| 1. |
- Andersson, Olov, 1979-, et al.
(author)
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WARA-PS : a research arena for public safety demonstrations and autonomous collaborative rescue robotics experimentation
- 2021
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In: Autonomous Intelligent Systems. - : Springer Nature. - 2730-616X. ; 1:1
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Journal article (peer-reviewed)abstract
- A research arena (WARA-PS) for sensing, data fusion, user interaction, planning and control of collaborative autonomous aerial and surface vehicles in public safety applications is presented. The objective is to demonstrate scientific discoveries and to generate new directions for future research on autonomous systems for societal challenges. The enabler is a computational infrastructure with a core system architecture for industrial and academic collaboration. This includes a control and command system together with a framework for planning and executing tasks for unmanned surface vehicles and aerial vehicles. The motivating application for the demonstration is marine search and rescue operations. A state-of-art delegation framework for the mission planning together with three specific applications is also presented. The first one concerns model predictive control for cooperative rendezvous of autonomous unmanned aerial and surface vehicles. The second project is about learning to make safe real-time decisions under uncertainty for autonomous vehicles, and the third one is on robust terrain-aided navigation through sensor fusion and virtual reality tele-operation to support a GPS-free positioning system in marine environments. The research results have been experimentally evaluated and demonstrated to industry and public sector audiences at a marine test facility. It would be most difficult to do experiments on this large scale without the WARA-PS research arena. Furthermore, these demonstrator activities have resulted in effective research dissemination with high public visibility, business impact and new research collaborations between academia and industry.
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| 2. |
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| 3. |
- Chábera, Pavel, et al.
(author)
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Band-selective dynamics in charge-transfer excited iron carbene complexes
- 2019
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In: Faraday Discussions. - : Royal Society of Chemistry (RSC). - 1359-6640 .- 1364-5498. ; 216:2019, s. 191-210
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Journal article (peer-reviewed)abstract
- Ultrafast dynamics of photoinduced charge transfer processes in light-harvesting systems based on Earth-abundant transition metal complexes are of current interest for the development of molecular devices for solar energy conversion applications. A combination of ultrafast spectroscopy and first principles quantum chemical calculations of a recently synthesized iron carbene complex is used to elucidate the ultrafast excited state evolution processes in these systems with particular emphasis on investigating the underlying reasons why these complexes show promise in terms of significantly extended lifetimes of charge transfer excited states. Together, our results challenge the traditional excited state landscape for iron-based light harvesting transition metal complexes through radically different ground and excited state properties in alternative oxidation states. This includes intriguing indications of rich band-selective excited state dynamics on ultrafast timescales that are interpreted in terms of excitation energy dependence for excitations into a manifold of charge-transfer states. Some implications of the observed excited state properties and photoinduced dynamics for the utilization of iron carbene complexes for solar energy conversion applications are finally discussed.
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| 4. |
- Chábera, Pavel, et al.
(author)
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Photofunctionality of iron(III) N-heterocyclic carbenes and related d5 transition metal complexes
- 2021
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In: Coordination Chemistry Reviews. - : Elsevier BV. - 0010-8545. ; 426
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Research review (peer-reviewed)abstract
- Despite a few reports of photoluminescent and strongly photo-oxidizing transition metal complexes with a d5 electronic configuration, the photophysics and photochemistry of this class of transition metal complexes have largely remained unexplored. Recent investigations of earth-abundant iron(III) N-heterocyclic carbene (NHC) complexes have demonstrated promising photophysical and photochemical properties associated with low-spin (doublet) ligand-to-metal charge transfer (2LMCT) excitations, including nanosecond photoluminescence (PL) and capabilities to drive both photo-oxidation and photo-reduction reactions. These encouraging results are at first sight surprising in light of the general scarcity of known photofunctional complexes of any transition metal complexes with a d5 electronic configuration, including 1st, 2nd and 3rd row transition metal complexes of Mn(II), Tc(II), Re(II), Fe(III), Ru(III) and Os(III). Here, we review the photophysical and photochemical properties of the new Fe(III) NHC complexes together with related d5 transition metal complexes as a basis for a broader understanding of the unorthodox photophysical and photochemical properties associated with this open-shell electronic configuration. This includes considerations of the role of charge and spin effects on the ground state electronic structure, as well as discussions of charge transfer (CT) and metal centered (MC) excited state properties. The special properties of 2LMCT excited states are emphasized as a key feature to understand the photophysics of many photofunctional d5 transition metal complexes. Further aspects of excited state dynamics with d5 light-harvesting complexes, including both intra- and inter-molecular charge transfer processes, are also discussed. Finally, some fundamental challenges and emerging opportunities for further development of photofunctional Fe(III) NHC and related LMCT/d5 complexes for light-harvesting, light-emitting, and photo(electro)chemical applications are outlined. This includes some general considerations of how the specific photochemical properties of the LMCT/d5 complexes provides an exciting opportunity to develop a unique niche within the diversity of photofunctional molecular systems alongside other types of organic and inorganic chromophores commonly used in the field of molecular photochemistry.
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| 5. |
- Kaufhold, Simon, et al.
(author)
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Microsecond Photoluminescence and Photoreactivity of a Metal-Centered Excited State in a Hexacarbene-Co(III) Complex
- 2021
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In: Journal of the American Chemical Society. - : American Chemical Society (ACS). - 0002-7863 .- 1520-5126. ; , s. 1307-1312
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Journal article (peer-reviewed)abstract
- The photofunctionality of the cobalt-hexacarbene complex [Co(III)(PhB(MeIm)3)2]+ (PhB(MeIm)3 = tris(3-methylimidazolin-2-ylidene)(phenyl)borate) has been investigated by time-resolved optical spectroscopy. The complex displays a weak (φ ∼10-4) but remarkably long-lived (τ ∼1 μs) orange photoluminescence at 690 nm in solution at room temperature following excitation with wavelengths shorter than 350 nm. The strongly red-shifted emission is assigned from the spectroscopic evidence and quantum chemical calculations as a rare case of luminescence from a metal-centered state in a 3d6 complex. Singlet oxygen quenching supports the assignment of the emitting state as a triplet metal-centered state and underlines its capability of driving excitation energy transfer processes.
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| 6. |
- Kjær, Kasper Skov, et al.
(author)
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Luminescence and reactivity of a charge-transfer excited iron complex with nanosecond lifetime
- 2019
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In: Science. - : American Association for the Advancement of Science (AAAS). - 0036-8075 .- 1095-9203. ; 363:6424, s. 249-253
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Journal article (peer-reviewed)abstract
- Iron’s abundance and rich coordination chemistry are potentially appealing features for photochemical applications. However, the photoexcitable charge-transfer (CT) states of most Fe complexes are limited by picosecond or sub-picosecond deactivation through low-lying metal centered (MC) states, resulting in inefficient electron transfer reactivity and complete lack of photoluminescence. Here we show that octahedral coordination of Fe(III) by two mono-anionic facial tris-carbene ligands can suppress such deactivation dramatically. The resulting complex [Fe(phtmeimb)2]+, where phtmeimb is [phenyl(tris(3-methylimidazol-1-ylidene))borate]-, exhibits strong, visible, room temperature photoluminescence with a 2.0 ns lifetime and 2% quantum yield via spin-allowed transition from a ligand-to-metal charge-transfer (2 LMCT) state to the ground state (2 GS). Reductive and oxidative electron transfer reactions were observed for the2 LMCT state of [Fe(phtmeimb)2]+ in bimolecular quenching studies with methylviologen and diphenylamine.
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| 7. |
- Kolesnichenko, Pavel V., et al.
(author)
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Viking Spectrophotometer : A Home-Built, Simple, and Cost-Efficient Absorption and Fluorescence Spectrophotometer for Education in Chemistry
- 2023
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In: Journal of Chemical Education. - : American Chemical Society (ACS). - 0021-9584 .- 1938-1328. ; 100:3, s. 1128-1137
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Journal article (peer-reviewed)abstract
- Investigating the optical properties of various chemical compounds using UV-vis spectrophotometers is an essential part of education in chemistry. However, commercial spectrophotometers are usually treated as "magic black boxes", where the dominant majority of optical elements are hidden "under the hood". This often limits understanding of the mechanisms behind the generation of spectral curves, which in turn may impede the ability to understand the limitations of the applied method and, in some cases, interpret the acquired data. In addition, the study of optical emission phenomena using fluorescence spectrophotometers is seldom implemented in educational laboratories due to the practical challenges and costs of the devices, which severely limit pedagogic access to this topic. For students to be more confident with these two basic spectroscopy techniques, we have developed a laboratory kit that provides a multifaceted learning experience. Starting with a basic exploration of an instrument assembly, it teaches, for example, such technical concepts as spectral resolution and detection sensitivity. More fundamentally, it enables deeper learning of the Beer-Lambert law and the notion of Stokes shift. The spectrophotometer is built from cost-efficient materials and is easily scalable, making it affordable for many educational laboratories. Due to a modular design, it is adaptable to various levels of education and has been successfully applied during high school-, undergraduate-, and graduate-level classes.
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| 8. |
- Lindh, Linnea, et al.
(author)
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Dye-sensitized solar cells based on Fe N-heterocyclic carbene photosensitizers with improved rod-like push-pull functionality
- 2021
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In: Chemical Science. - : Royal Society of Chemistry (RSC). - 2041-6520 .- 2041-6539. ; 12:48, s. 16035-16053
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Journal article (peer-reviewed)abstract
- A new generation of octahedral iron(ii)-N-heterocyclic carbene (NHC) complexes, employing different tridentate C^N^C ligands, has been designed and synthesized as earth-abundant photosensitizers for dye sensitized solar cells (DSSCs) and related solar energy conversion applications. This work introduces a linearly aligned push-pull design principle that reaches from the ligand having nitrogen-based electron donors, over the Fe(ii) centre, to the ligand having an electron withdrawing carboxylic acid anchor group. A combination of spectroscopy, electrochemistry, and quantum chemical calculations demonstrate the improved molecular excited state properties in terms of a broader absorption spectrum compared to the reference complex, as well as directional charge-transfer displacement of the lowest excited state towards the semiconductor substrate in accordance with the push-pull design. Prototype DSSCs based on one of the new Fe NHC photosensitizers demonstrate a power conversion efficiency exceeding 1% already for a basic DSSC set-up using only the I−/I3−redox mediator and standard operating conditions, outcompeting the corresponding DSSC based on the homoleptic reference complex. Transient photovoltage measurements confirmed that adding the co-sensitizer chenodeoxycholic acid helped in improving the efficiency by increasing the electron lifetime in TiO2. Time-resolved spectroscopy revealed spectral signatures for successful ultrafast (<100 fs) interfacial electron injection from the heteroleptic dyes to TiO2. However, an ultrafast recombination process results in undesirable fast charge recombination from TiO2back to the oxidized dye, leaving only 5-10% of the initially excited dyes available to contribute to a current in the DSSC. On slower timescales, time-resolved spectroscopy also found that the recombination dynamics (longer than 40 μs) were significantly slower than the regeneration of the oxidized dye by the redox mediator (6-8 μs). Therefore it is the ultrafast recombination down to fs-timescales, between the oxidized dye and the injected electron, that remains as one of the main bottlenecks to be targeted for achieving further improved solar energy conversion efficiencies in future work.
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| 9. |
- Lindh, Linnea, et al.
(author)
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Multifaceted Deactivation Dynamics of Fe(II) N-Heterocyclic Carbene Photosensitizers
- 2023
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In: Journal of Physical Chemistry A. - 1089-5639. ; 127:48, s. 10210-10222
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Journal article (peer-reviewed)abstract
- Excited state dynamics of three iron(II) carbene complexes that serve as prototype Earth-abundant photosensitizers were investigated by ultrafast optical spectroscopy. Significant differences in the dynamics between the investigated complexes down to femtosecond time scales are used to characterize fundamental differences in the depopulation of triplet metal-to-ligand charge-transfer (3MLCT) excited states in the presence of energetically accessible triplet metal-centered (3MC) states. Novel insights into the full deactivation cascades of the investigated complexes include evidence of the need to revise the deactivation model for a prominent iron carbene prototype complex, a refined understanding of complex 3MC dynamics, and a quantitative discrimination between activated and barrierless deactivation steps along the 3MLCT → 3MC → 1GS path. Overall, the study provides an improved understanding of photophysical limitations and opportunities for the use of iron(II)-based photosensitizers in photochemical applications.
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| 10. |
- Lindh, Linnea
(author)
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Photophysics and Photochemistry of Iron Carbene Complexes
- 2023
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Doctoral thesis (other academic/artistic)abstract
- Nature captures sunlight via light-absorbing molecules.Similarly, photosensitisers are used in applications of solar cells and artificial photosynthesis to absorb sunlight, and transfer the excited electron.Successful photosensitisers have in the past been based on a Ru polipyridyl scaffold, despite Ru being one of the scarcest elements in Earth's crust.This thesis work aims to replace Ru polipyridyl complexes by Fe carbene complexes, that by clever ligand design have approached suitable photosensitiser properties.One crucial property that is not yet competitive for Fe carbene photosensitisers is how long they stay in the excited state, i.e. their lifetime. This is controlled by the deactivation pathways of the molecule, dictated by the excited state landscape. Several Fe carbene photosensitisers were in this thesis investigated by spectroscopic and computational methods, to understand their deactivation pathways. For the Fe(II) carbene complexes investigated, small changes in the ligand structure influenced both what excited state (charge-transfer or metal-centred) that was mainly populated and the lifetime of the state.For the Fe(III) carbene complexes investigated, there was instead one dominating charge-transfer excited state that was rather unaffected by changes to the ligand. Furthermore, for the Fe(II) complexes metal-centred states played a large role in the deactivation pathway but for the Fe(III) complexes this was not the case.Also, one Co(III) carbene complex was investigated which displays remarkable long lifetime and emission from a metal-centred state.As a first step towards application, the electron-transfer properties of some of the photosensitisers were investigated.Fe(II) complexes with a push-pull design were able to transfer electrons to TiO2 in a solar cell configuration.The solar cell performance was however limited by an ultrafast recombination reaction, that brought a majority of the transferred electrons back to the photosensitiser.The Fe(III) complexes investigated had long enough lifetime to participate in electron transfer with other molecules in solution, if the concentration was high.Furthermore, at very high concentrations of the photosensitiser a light-induced charge-disproportionation reaction outcompeted all other deactivation pathways. In a heterogeneous catalysis configuration, this reaction could generate long-lived Fe(IV) species with the correct additives.The thesis work thus provide fundamental insights to the early implementations of Fe carbene photosensitisers in applications, by resolving key electron-transfer processes on the ultrafast timescale.
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| 11. |
- Lindh, Linnea, et al.
(author)
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Photophysics and photochemistry of iron carbene complexes for solar energy conversion and photocatalysis
- 2020
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In: Catalysts. - : MDPI AG. - 2073-4344. ; 10:3
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Research review (peer-reviewed)abstract
- Earth-abundant first row transition metal complexes are important for the development of large-scale photocatalytic and solar energy conversion applications. Coordination compounds based on iron are especially interesting, as iron is the most common transition metal element in the Earth’s crust. Unfortunately, iron-polypyridyl and related traditional iron-based complexes generally suffer from poor excited state properties, including short excited-state lifetimes, that make them unsuitable for most light-driven applications. Iron carbene complexes have emerged in the last decade as a new class of coordination compounds with significantly improved photophysical and photochemical properties, that make them attractive candidates for a range of light-driven applications. Specific aspects of the photophysics and photochemistry of these iron carbenes discussed here include long-lived excited state lifetimes of charge transfer excited states, capabilities to act as photosensitizers in solar energy conversion applications like dye-sensitized solar cells, as well as recent demonstrations of promising progress towards driving photoredox and photocatalytic processes. Complementary advances towards photofunctional systems with both Fe(II) complexes featuring metal-to-ligand charge transfer excited states, and Fe(III) complexes displaying ligand-to-metal charge transfer excited states are discussed. Finally, we outline emerging opportunities to utilize the improved photochemical properties of iron carbenes and related complexes for photovoltaic, photoelectrochemical and photocatalytic applications.
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| 12. |
- Lindh, Linnea, et al.
(author)
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Side-group switching between metal-to-ligand charge-transfer and metal-centered excited state properties in iron(II) N-heterocyclic carbene complexes
- 2024
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In: Coordination Chemistry Reviews. - 0010-8545. ; 506
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Research review (peer-reviewed)abstract
- Fe(II) N-heterocyclic carbene (NHC) complexes have emerged over the last decade as a promising class of light-harvesting complexes for a variety of photochemical applications relying on the presence of high-energy excited states of mainly charge-transfer character with excited state lifetimes of tens of picoseconds or longer. Recent spectroscopic investigations have significantly refined the understanding of some of the key prototype complexes of this kind and highlighted the subtle balance between population of triplet metal-to-ligand charge-transfer (3MLCT) and triplet metal-centered (3MC) states as a key issue to better understand and ultimately control the excited state dynamics in these complexes. To present a broader perspective on this issue, we here re-examine and discuss the excited state properties of a series of complexes with different side-groups on a common Fe NHC scaffold. Both the steady-state absorption spectrum and excited state dynamics are influenced by the side-group substitution, and the changes are rationalized based on shifting of the lowest metal-to-ligand charge-transfer (MLCT) state in energy based on the electron-withdrawing or electron-donating properties of the side-groups. Only electron-withdrawing substituents such as carboxylic acid groups ensured that the majority excited population stays in the 3MLCT state for ∼20 ps rather than rapidly converting into metal-centered (MC) states. In other complexes, the 3MLCT state survived <300 fs after which the 3MC state was populated for ∼10 ps. The transient absorption results also show that the dynamics can be switched in a simple manner by deprotonating the carboxylic acid group, which renders some of the complexes pH-sensitive. For the here discussed complexes, the results from transient absorption measurements indicate that the 3MLCT and 3MC states were close enough in energy to enable the side-group to determine the photophysics. The emerging understanding of the 3MLCT-3MC balance, as well as the nature and properties of the 3MC state in these complexes with intermediate ligand field strength is used to provide a broader fundamental perspective required to improve the ligand-design of Fe carbene complexes for issues such as to ensure a long-lived 3MLCT state.
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| 13. |
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| 14. |
- Prakash, Om, et al.
(author)
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Photophysical Integrity of the Iron(III) Scorpionate Framework in Iron(III)-NHC Complexes with Long-Lived 2LMCT Excited States
- 2022
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In: Inorganic Chemistry. - : American Chemical Society (ACS). - 0020-1669 .- 1520-510X. ; 61:44, s. 17515-17526
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Journal article (peer-reviewed)abstract
- Fe(III) complexes with N-heterocyclic carbene (NHC) ligands belong to the rare examples of Earth-abundant transition metal complexes with long-lived luminescent charge-transfer excited states that enable applications as photosensitizers for charge separation reactions. We report three new hexa-NHC complexes of this class: [Fe(brphtmeimb)2]PF6 (brphtmeimb = [(4-bromophenyl)tris(3-methylimidazol-2-ylidene)borate]–, [Fe(meophtmeimb)2]PF6 (meophtmeimb = [(4-methoxyphenyl)tris(3-methylimidazol-2-ylidene)borate]–, and [Fe(coohphtmeimb)2]PF6 (coohphtmeimb = [(4-carboxyphenyl)tris(3-methylimidazol-2-ylidene)borate]–. These were derived from the parent complex [Fe(phtmeimb)2]PF6 (phtmeimb = [phenyltris(3-methylimidazol-2-ylidene)borate]– by modification with electron-withdrawing and electron-donating substituents, respectively, at the 4-phenyl position of the ligand framework. All three Fe(III) hexa-NHC complexes were characterized by NMR spectroscopy, high-resolution mass spectroscopy, elemental analysis, single crystal X-ray diffraction analysis, electrochemistry, Mößbauer spectroscopy, electronic spectroscopy, magnetic susceptibility measurements, and quantum chemical calculations. Their ligand-to-metal charge-transfer (2LMCT) excited states feature nanosecond lifetimes (1.6–1.7 ns) and sizable emission quantum yields (1.7–1.9%) through spin-allowed transition to the doublet ground state (2GS), completely in line with the parent complex [Fe(phtmeimb)2]PF6 (2.0 ns and 2.1%). The integrity of the favorable excited state characteristics upon substitution of the ligand framework demonstrates the robustness of the scorpionate motif that tolerates modifications in the 4-phenyl position for applications such as the attachment in molecular or hybrid assemblies.
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| 15. |
- Prakash, Om, et al.
(author)
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Tailoring the Photophysical Properties of a Homoleptic Iron(II) Tetra N-Heterocyclic Carbene Complex by Attaching an Imidazolium Group to the (C∧N∧C) Pincer Ligand─A Comparative Study
- 2024
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In: Inorganic Chemistry. - : American Chemical Society (ACS). - 0020-1669 .- 1520-510X. ; 63:6, s. 2909-2918
-
Journal article (peer-reviewed)abstract
- We here report the synthesis of the homoleptic iron(II) N-heterocyclic carbene (NHC) complex [Fe(miHpbmi)2](PF6)4 (miHpbmi = 4-((3-methyl-1H-imidazolium-1-yl)pyridine-2,6-diyl)bis(3-methylimidazol-2-ylidene)) and its electrochemical and photophysical properties. The introduction of the π-electron-withdrawing 3-methyl-1H-imidazol-3-ium-1-yl group into the NHC ligand framework resulted in stabilization of the metal-to-ligand charge transfer (MLCT) state and destabilization of the metal-centered (MC) states. This resulted in an improved excited-state lifetime of 16 ps compared to the 9 ps for the unsubstituted parent compound [Fe(pbmi)2](PF6)2 (pbmi = (pyridine-2,6-diyl)bis(3-methylimidazol-2-ylidene)) as well as a stronger MLCT absorption band extending more toward the red spectral region. However, compared to the carboxylic acid derivative [Fe(cpbmi)2](PF6)2 (cpbmi = 1,1′-(4-carboxypyridine-2,6-diyl)bis(3-methylimidazol-2-ylidene)), the excited-state lifetime of [Fe(miHpbmi)2](PF6)4 is the same, but both the extinction and the red shift are more pronounced for the former. Hence, this makes [Fe(miHpbmi)2](PF6)4 a promising pH-insensitive analogue of [Fe(cpbmi)2](PF6)2. Finally, the excited-state dynamics of the title compound [Fe(miHpbmi)2](PF6)4 was investigated in solvents with different viscosities, however, showing very little dependency of the depopulation of the excited states on the properties of the solvent used.
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| 16. |
- Rosemann, Nils W., et al.
(author)
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Competing dynamics of intramolecular deactivation and bimolecular charge transfer processes in luminescent Fe(iii) N-heterocyclic carbene complexes
- 2023
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In: Chemical Science. - : Royal Society of Chemistry (RSC). - 2041-6520 .- 2041-6539. ; 14:13, s. 3569-3579
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Journal article (peer-reviewed)abstract
- Steady state and ultrafast spectroscopy on [FeIII(phtmeimb)2]PF6 (phtmeimb = phenyl(tris(3-methylimidazol-2-ylidene))borate) was performed over a broad range of temperatures. The intramolecular deactivation dynamics of the luminescent doublet ligand-to-metal charge-transfer (2LMCT) state was established based on Arrhenius analysis, indicating the direct deactivation of the 2LMCT state to the doublet ground state as a key limitation to the lifetime. In selected solvent environments photoinduced disproportionation generating short-lived Fe(iv) and Fe(ii) complex pairs that subsequently undergo bimolecular recombination was observed. The forward charge separation process is found to be temperature-independent with a rate of ∼1 ps−1. Subsequent charge recombination takes place in the inverted Marcus region with an effective barrier of 60 meV (483 cm−1). Overall, the photoinduced intermolecular charge separation efficiently outcompetes the intramolecular deactivation over a broad range of temperatures, highlighting the potential of [FeIII(phtmeimb)2]PF6 to perform photocatalytic bimolecular reactions.
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| 17. |
- Siverbo, Sven, 1970-, et al.
(author)
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#metoo-management
- 2018
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Book (other academic/artistic)abstract
- För ett drygt år sedan inleddes #metoo-rörelsen, vilken påminner oss om att det finns brister i samhället även om allt ser bra ut på ytan. Mycket talar för att #metoo inte är en övergående fluga. Det handlar inte om en samordnad aktion med ett tydligt mål och det finns heller ingen ledare för rörelsen. #metoo är en självorganiserad rörelse, ett sätt att synliggöra det som under snart sagt hela mänsklighetens historia har förtigits, förnekats och bagatelliserats trots att alla har vetat. Den här rapporten belyser #metoo-rörelsens inverkan på organisationer ur ett managementperspektiv. Vi är intresserade av fenomenet #metoo-management, vilket vi definierar som organisationers arbete med att förebygga och hantera sexuella trakasserier som en följd av #metoo-rörelsen. Det första syftet med rapporten är att ta reda på om #metoo-management förekommer. Det andra syftet är att utforska hur organisationer arbetar med #metoo-management. Det tredje syftet är att förklara varför organisationer väljer att arbeta med #metoo- management på olika sätt. Baserat på intervjuer med företrädare för tio organisationer – i flera fall väldigt olika – har vi konstaterat att #metoo-rörelsen har gett upphov till #metoo- management. Mer precist handlar #metoo-management om flera olika åtgärder och aktiviteter. Organisationer har återupprepat och preciserat sina programförklaringar mot sexuella trakasserier. Programmen har fått förnyad spridning på arbetsplatserna och ytterligare åtgärder för programefterlevnad har vidtagits. Procedurer för klagomålshantering har utvecklats, utbildningar har initierats och riskfaktorer har identifierats och reducerats. Inte minst har förekomsten av problem med sexuella trakasserier inventerats. Något överraskande kunde vi notera att det inte fanns något exempel på att programmen mot sexuella trakasserier utvärderades och att det saknades planer för att minska beroendeförhållanden mellan chefer och anställda i de organisationer där dessa var betydande. Det är viktigt att betona att det finns betydande skillnader mellan organisationer i hur intensivt arbetet med #metoo-management har bedrivits. Skillnaderna förefaller bero på flera olika faktorer. En är att incidensen av sexuella trakasserier är olika och en annan att organisationer gör olika bedömningar av hur stor skada uppdagade fall skulle göra på arbetsgivarvarumärket. Ytterligare förklaringar till intensiteten i arbetet är skillnader i hur ambitiöst arbetet har varit innan #metoo- rörelsen och att det i vissa organisationer finns större kunskaper om riskfaktorer än i andra. Slutligen förefaller organisationens storlek och synlighet spela roll genom att de är mer påpassade och därför har större anledning att undvika problem som väcker negativ uppmärksamhet
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| 18. |
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| 19. |
- Strinnholm, Åsa, 1962-
(author)
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Food hypersensitivity among schoolchildren : prevalence, Health Related Quality of Life and experiences of double-blind placebo-controlled food challenges
- 2017
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Doctoral thesis (other academic/artistic)abstract
- Background: The prevalence of reported food hypersensitivity among children has increased in Western countries. However, the prevalence varies largely due to differences in methods used in different studies. Double-blind placebo-controlled food challenge (DBPCFC) is the most reliable method to verify or exclude food hypersensitivity. The use of double-blind food challenges is increasing in clinical praxis, but since the method is time- and resource consuming it is rarely used in population-based cohort studies. There is a lack of knowledge on how adolescents and mothers experience participation in double-blind placebocontrolled food challenges and to what extent the food is reintroduced after a negative challenge. While several studies have described the impact of IgEmediated food allergy on Health-Related Quality of Life (HRQL), few studies have described HRQL among children with other food hypersensitivity phenotypes.Aim: The aim of this thesis was to estimate the prevalence of reported food hypersensitivity, associated risk factors, and symptom expressions among schoolchildren. We also examined HRQL among children with total elimination of cow's milk, hen’s egg, fish or wheat due to food hypersensitivity as a group compared with children with unrestricted diet, and after we categorised the children with eliminated foods into different phenotypes of FHS. Finally, adolescents' and mothers' experience of DBPCFC was examined as well if the food had been reintroduced.Methods: Three studies were based on the Obstructive Lung Disease in Northern Sweden (OLIN) paediatric cohort II. The cohort was recruited in 2006 when all children in first and second grade (7-8 years) in three municipalities in Norrbotten were invited to a parental questionnaire study and 2,585 (96% of invited) participated. The questionnaire included questions about food hypersensitivity, asthma, rhinitis, eczema and possible risk factors. The children in two municipalities were also invited to skin prick testing with 10 airborne allergens, and 1,700 (90%) participated. Paper I is based on this initial survey of the cohort. Four years later, at age 11-12 years, the cohort was followed up using the same methods and with the same high participation rate. At the follow-up, 125 children (5% of the cohort) reported total elimination of cow's milk, hen's egg, fish or wheat due to food hypersensitivity. These children were invited to a clinical examination and to complete a generic (KIDSCREEN-52) and a diseasespecific HRQL questionnaire (FAQLQ-TF) (n=75). Based on the clinical examination the children were categorised into different phenotypes of food hypersensitivity: current food allergy, outgrown food allergy and lactose intolerance. In addition, a random sample of children with unrestricted diet from the same cohort, answered the generic questionnaire (n=209). Paper II is based on this HRQL study. Children categorised as having current food allergy were invited to a further evaluation including DBPCFC. Eighteen months after the challenges, these children were interviewed about their experiences during and after the challenge (n=17). Paper III is based on these interviews. Paper IV was based on interviews with mothers to children referred to a paediatric allergy specialist for evaluation of food allergy using DBPCFC (n=8). In the two interview studies results were analysed using qualitative content analysis.Results: At age 7-8 years, the prevalence of reported food hypersensitivity was 21%. Food hypersensitivity to milk, egg, fish, wheat or soy was reported by 10.9% and hypersensitivity to fruits or nuts by 14.6%. The most common essential food to trigger symptoms was milk, reported by 9%. The most frequently reported food induced symptoms, were oral symptoms mainly caused by fruits, followed by gastrointestinal symptoms mainly caused by milk. The risk factor pattern was different for food hypersensitivity to milk compared to hypersensitivity to other foods. No significant difference in distribution in generic or disease-specific HRQL was found among children with reported total elimination of milk, egg, fish and/or wheat due to FHS compared to children with unrestricted diet. However, a trend indicated that the disease-specific HRQL was most impaired among children with current food allergy compared to children with outgrown food allergy and lactose intolerance. The proportion of poor HRQL defined as ≥75 percentile was significantly higher among children with current food allergy than the other phenotypes. A DBPCFC was an opportunity for the adolescents and the mothers to overcome the fear of reactions to food that had been eliminated for a long time. After the challenge, when the food was partially or fully reintroduced, socializing became easier and both adolescents and mothers experienced more freedom regarding food intake. A negative challenge was not consistently associated with reintroduction of the food. Reasons for reintroduction failure were fear of allergic reactions, that the adolescent did not like the taste of the food, or that living with an elimination diet was considered as normal. Conclusion In this population-based study, one in five of children at age 7-8 years reported food hypersensitivity to any food. The generic HRQL was similar among children with and without food hypersensitivity. However, poor disease-specific HRQL was more common among children with current food allergy compared to children with other FHS phenotypes. If the tested food was reintroduced after a DBPCFC, both adolescents and mothers described a changed life with less fear, and that life had become easier regarding meal preparations and social events. As reintroduction failure was present despite a negative food challenge, follow-ups and evaluations of food reintroduction should be performed independent of the outcome of a food challenge.
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| 20. |
- Strinnholm, Åsa, et al.
(author)
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Health Related Quality of Life among schoolchildren aged 12-13 years in relation to food hypersensitivity phenotypes : a population-based study
- 2017
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In: Clinical and Translational Allergy. - : BioMed Central. - 2045-7022. ; 7
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Journal article (peer-reviewed)abstract
- Background:While Health Related Quality of Life has been investigated among children with IgE-mediated food allergy, less is known about quality of life among children with other types of hypersensitivity to food. The aim of this study was to investigate Health Related Quality of Life (HRQL) in children with and without food hypersensitivity. Further, we compared HRQL between children with different phenotypes of food hypersensitivity. Methods:In a large population-based cohort of schoolchildren in Northern Sweden, the parents of 2,612 (96% of invited) completed a questionnaire. All 125 (5%) children who reported complete elimination of milk, egg, fish or wheat due to food hypersensitivity were invited to a clinical examination and 94 children participated. Of these, 75 children also completed a generic (KIDSCREEN -52) and a disease-specific HRQL questionnaire (FAQLQ-TF). Thereafter, these children were categorised into the different phenotypes: current food allergy, outgrown food allergy, and lactose intolerance. Additionally, 209 children with unrestricted diets answered the generic questionnaire.Results:The median score of all KIDSCREEN -52 domains were above the population norm of 50 both in children with and without food hypersensitivity. No significant differences in distribution in generic or disease-specific HRQL were found between children with or without food hypersensitivity. There were no significant differences in HRQL between children with different phenotypes of food hypersensitivity. However, children with current food allergy tended to have the lowest HRQL. Further, poor HRQL defined as ≥75th percentile for the disease specific score was significantly more common in the current food allergy phenotype in the domain Emotional impact and the total FAQLQ, compared to the other phenotypes.Conclusions: In this population-based study, 12-13 year old children reported good HRQL regardless of having food hypersensitivity or not. However, the children with the current phenotype reported lower HRQL than the other phenotypes.
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| 21. |
- Strinnholm, Åsa, et al.
(author)
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Reintroduction failure is common among adolescents after double-blind placebo-controlled food challenges
- 2017
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In: Acta Paediatrica. - : Wiley. - 0803-5253 .- 1651-2227. ; 106:2, s. 282-287
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Journal article (peer-reviewed)abstract
- AIM: There has been a lack of research on adolescents' who undergo double-blind placebo-controlled food challenges. The aim of this study was to investigate food allergic adolescents' experiences and consequences of double-blind placebo-controlled food challenges.METHODS: This qualitative, descriptive interview study included 17 adolescents aged 14-15 years with total elimination of cows' milk, hens' eggs or cod due to food allergies. The participants, who were initially identified from a large population-based cohort study, were interviewed 18 months after completing their challenges.RESULTS: The double-blind placebo-controlled food challenge proved to be a complex experience for the adolescents, involving fear of potential reactions and the hope that the food could be reintroduced. Experiences during the challenge were described in three themes: facing fears in a secure environment, being hesitant but curious about unknown tastes and waiting for unknown food reactions. Experiences after the challenge were desribed in two themes: gaining control and freedom and continuing old habits. A negative challenge was not consistently associated with the reintroduction of the challenged food.CONCLUSION: This study highlighted the importance of considering the adolescents' expectations and experiences of the challenge and the reintroduction process to ensure desirable changes in their dietary habits. Follow ups should be performed regardless of the outcome of challenges.
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| 22. |
- Strinnholm, Åsa, et al.
(author)
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To face fear : a qualitative study of adolescents' experiences of double-blind, placebo-controlled food challenges
- 2015
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In: Allergy. European Journal of Allergy and Clinical Immunology. - : Wiley. - 0105-4538 .- 1398-9995. ; 70, s. 386-386
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Journal article (other academic/artistic)abstract
- Background: Double-blind, placebo-controlled food challenges are the gold standard for diagnosing the clinical relevance of a suspected food allergy. Hitherto there are no descriptions on how adolescents' experience this procedure. The aim of this study was to describe adolescents' experiences of double-blind, placebo-controlled food challenges and to what extent the provoked food was reintroduced following the challenge. Method: Seventeen adolescents were interviewed after participating in double-blind, placebo-controlled food challenges. The interview data was analyzed using qualitative content analysis.Results: Experiences during the challenge were: challenging fears in a secure environment, being curious but also hesitant to unknown tastes and waiting for unknown food reactions. Experiences after the challenge were: gaining control and freedom or to stay in old habits. Out of 20 challenges the outcome was negative in 11 cases and positive in 9. Five adolescents with a negative outcome and 4 with mild reactions reintroduced the provoked food. Conclusions: During the challenge the adolescents received knowledge about whether and how they reacted to the provoked food. Reintroduction of the food was not always consistent with the challenge outcome. Independent of the outcome of the challenge and the choices made based on the challenge result, all the adolescents strived for what they felt was a normal life. This study provides a better understanding of young people's experience of double-blind, placebo-controlled food challenge and their motivations to introduce -or not- the previously eliminated food. The result indicate that follow ups are important since the adolescents need support in their striving to manage new food-related situations after the challenge, independent of the outcome.
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