| 1. |
- Abrahamsson, Maria, et al.
(författare)
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A new strategy for the improvement of photophysical properties in ruthenium(II) polypyridyl complexes. Synthesis and photophysical and electrochemical characterization of six mononuclear ruthenium(II) bisterpyridine-type complexes
- 2005
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Ingår i: Inorganic Chemistry. - : American Chemical Society (ACS). - 0020-1669 .- 1520-510X. ; 44:9, s. 3215-3225
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Tidskriftsartikel (refereegranskat)abstract
- The synthesis and characterization of six ruthenium(II) bistridentate polypyridyl complexes is described. These were designed on the basis of a new approach to increase the excited-state lifetime of ruthenium(II) bisterpyridine-type complexes. By the use of a bipyridylpyridyl methane ligand in place of terpyridine, the coordination environment of the metal ion becomes nearly octahedral and the rate of deactivation via ligand-field (i.e., metal-centered) states was reduced as shown by temperature-dependent emission lifetime studies. Still, the possibility to make quasi-linear donor-ruthenium-acceptor triads is maintained in the complexes. The most promising complex shows an excited-state lifet me of tau = 15 ns in alcohol solutions at room temperature, which should be compared to a lifetime of tau = 0.25 ns for [Ru(tpy)(2)](2+). The X-ray structure of the new complex indeed shows a more octahedral geometry than that of [Ru(tpy)(2)](2+). Most importantly, the high excited-state energy was retained, and thus, so was the potential high reactivity of the excited complex, which has not been the case with previously published strategies based on bistridentate complexes.
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| 2. |
- Anderlund, Magnus F., et al.
(författare)
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A new, dinuclear high spin manganese(III) complex with bridging phenoxy and methoxy groups. Structure and magnetic properties
- 2006
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Ingår i: Inorganic Chemistry Communications. - : Elsevier BV. - 1387-7003 .- 1879-0259. ; 9:12, s. 1195-1198
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Tidskriftsartikel (refereegranskat)abstract
- A new mu-phenoxy-mu-metoxy di-manganese(III) complex with the trisphenolic ligand, 2,6-bis[((2-hydroxybenzyl)(2-pyridylmethyl)amino)methyl]-4-methylphenol, was isolated as a perchlorate salt. The X-ray structure shows that the two manganese(III) ions are in a distorted octrahedral enviroment with approximately perpendicular Jahn-Teller axes. Investigation of the molar magnetic susceptibility reveals a ferromagnetic coupling between the two high-spin manganese(III) ions. Fitting of the data led to g = 2 and J = 12.5 cm(-1).
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| 3. |
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| 4. |
- Ivanov, Alexander V., et al.
(författare)
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Polycrystalline and surface O,O′-dialkyldithiophosphate zinc(II) complexes : preparation, 31P CP/MAS NMR and single-crystal X-ray diffraction studies
- 2001
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Ingår i: Inorganica Chimica Acta. - 0020-1693 .- 1873-3255. ; 315:1, s. 26-35
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Tidskriftsartikel (refereegranskat)abstract
- Dithiophosphate zinc(II) complexes with eight different O,O′-dialkyldithiophosphate ligands have been prepared in solid/liquid states and as surface complexes on a synthetic sphalerite, and studied by means of 31P NMR spectroscopy. All 31P resonances, corresponding to dithiophosphate ligands with different structural functions (i.e. terminal chelating or bridging between two metal atoms in bi- and tetranuclear complexes), have been assigned on the basis of comparative analyses of chemical shift data for solid complexes, their melts and chloroform solutions at various concentrations. The bridging coordination of O,O′-dialkyldithiophosphate ligands by the two neighbouring zinc(II) atoms was established in the case of zinc(II) complexes formed at the surface of the synthetic sphalerite. In addition, novel molecular and crystal structures of the binuclear O,O′-di-cyclo-hexyldithiophosphate zinc(II) complex have been resolved by single-crystal X-ray diffraction data analysis, and useful correlations with 31P NMR data for this complex were obtained.
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| 5. |
- Ivanov, Alexander V., et al.
(författare)
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Rotation isomers of bis(diethyldithiocarbamato)zinc(II) adduct with pyridine, Zn(EDtc)(2)center dot Py: ESR, C-13 and N-15 CP/MAS NMR and single-crystal X-ray diffraction studies
- 1999
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Ingår i: Polyhedron. - 0277-5387 .- 1873-3719. ; 18:15, s. 2069-2078
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Tidskriftsartikel (refereegranskat)abstract
- The adduct of bis(diethyldithiocarbamato)zinc(II) with pyridine, Zn(EDtc)2·Py, was prepared and studied by means of ESR (63Cu2+ and 65Cu2+ were used as spin labels), solid-state natural abundance 13C and 15N CP/MAS NMR spectroscopy and single-crystal X-ray diffraction data analysis. Two rotation isomers of the adduct were unambiguously determined by these three independent methods. It was found that these two isomers have different orientations of the pyridine ring about the N(Py)-Zn axis. The acute angles of the plane of the pyridine molecules relative to the most weak Zn-S bond are equal to 45.6 and 52.7° in the different isomers. Adduct molecules adopt a geometry which is intermediate between the square pyramidal (C4v) and the trigonal bipyramidal (D3h). All ESR and NMR resonances of Zn(EDtc)2·Py were assigned
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| 6. |
- Ivanov, Alexander V., et al.
(författare)
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The structural reorganisation of bis(diethyldithiocarbamato)morpholine-zinc(II) and -copper(II) in the course of solid-state solvation with morpholine and benzene molecules studied by ESR, solid-state 13C and 15N CP/MAS NMR spectroscopy and single-crystal X-ray diffraction
- 2001
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Ingår i: Inorganica Chimica Acta. - 0020-1693 .- 1873-3255. ; 321:1-2, s. 63-64
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Tidskriftsartikel (refereegranskat)abstract
- Six forms of both non-solvated and solvated adducts of bis(diethyldithiocarbamato)–zinc(II) and –copper(II) with morpholine, of general formulas [M{O(CH2)4NH}{S2CN(C2H5)2}2] and [M{O(CH2)4NH}{S2CN(C2H5)2}2]·L (M=Zn(II) (1): L=O(CH2)4NH (2), C6H6 (3); M=Cu(II) (4): L=O(CH2)4NH (5), C6H6 (6)), have been prepared and studied by means of ESR, solid-state natural abundance 13C and 15N CP/MAS NMR spectroscopy and single crystal X-ray diffraction data. The existence of two conformers, which are correlated as rotation isomers, was unambiguously established for both zinc(II) and copper(II) non-solvated adducts 1 and 4. These two isomeric forms are characterised by different modes of spatial orientation of the non-planar morpholine ring relative to the two four-membered metallochelate rings. The geometry of the adduct molecules is close to square pyramidal, C4v, and therefore the ground state of the unpaired copper(II) electron corresponds to the 3dx2−y2 atomic orbital (AO). Solvation of the studied adducts in the solid state leads to their significant structural reorganisation at the molecular level, i.e. their structural unification yielding qualitatively new structural states with: (i) different lengths of the Zn---N bond; (ii) reoriented heterocyclic ring of the coordinated morpholine molecule; and (iii) an enhanced contribution of trigonal-bipyramidal character to the geometry of the coordination polyhedra of the central atom (from 7.5 and 22.7% in original adducts to 75% in solvated forms). The type of geometry of the coordination polyhedrons in the solvated forms of the adducts (intermediate between trigonal bipyramid D3h and square pyramid C4v) correlates with the fact that the ground state of the unpaired copper(II) electron is a mixture of 3dz2 and 3dx2−y2 AOs. All observed ESR and NMR resonances have been assigned and are in agreement with the structures obtained from X-ray diffraction data.
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| 7. |
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| 8. |
- Kritikos, Mikael, et al.
(författare)
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Synthesis, Structure and Properties of ErNb2(OPri)13
- 2004
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Ingår i: Journal of Sol-Gel Science and Technology. ; 32, s. 25-29
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Tidskriftsartikel (refereegranskat)abstract
- The molecular alkoxide, ErNb2(OPri)13 was prepared by metathesis with 2KNb(OPri)6, KOPri and ErCl3, and structurally determined by single-crystal X-ray diffraction techniques. Each molecule contains a central Er3+-ion coordinates by six OPri groups placed, one via a double alkoxo-bridge and the other via a triple alkoxo.bridge. It is isostructural with LaNb2(OPri)13, in spite of the large difference in ionic radius between Er3+ and La3+ (16%). The compound was characterized by its IR- and UV-vis-NIR-spectroscopic fine structures, and found to be structurally intact in hexane:isopropanol solution.
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| 9. |
- Kritikos, Mikael, et al.
(författare)
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Synthesis, Structure and Properties of Na2Zn(OEt)4(HOEt)5
- 2004
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Ingår i: Journal of Sol-Gel Science and Technology. ; 32, s. 19-23
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Tidskriftsartikel (refereegranskat)abstract
- The synthesis, structure and properties of Na2Zn(OEt)4(HOEt)5, having the right Na:Zn ratio for sol-gel synthesis of the highly Na-ion conducting ceramic Nai1.8Zn0.9Si1.1O4, is described. It was synthesised in high yield by a metathesis reaction of ZnCl2 and 4NaOEt in ethanol or ethanol/toluene solvent. The structure was determined by single-crystal X-ray methods and consists of two symmetry related polymeric strands with the metal sequence ...-Zn-Na-Na-Zn-.... Extensive hydrogen bonding is present within each chain. Further characterization was lmade with IR- and Raman-spectroscopy and thermo-calorimetry, showing that the compound is stable to 65°C.
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| 10. |
- Kritikos, Mikael, et al.
(författare)
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Synthesis, structure and properties of two unexpected square pyramidal pentanuclear oxo-isopropoxide molecules : Ce5O(OPri)(13) and La5O(OPri)(13)(HOPri)(2)
- 2012
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Ingår i: Inorganica Chimica Acta. - : Elsevier BV. - 0020-1693 .- 1873-3255. ; 384, s. 125-132
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Tidskriftsartikel (refereegranskat)abstract
- The synthesis, structure and properties of two pentanuclear oxo-alkoxides are described. A combination of metathesis of LnCl(3) and 3KOPr(i) and stoichiometric hydrolysis resulted in the solvated oxo-alkoxide La5O(OPri)(13)(HOPri)(2) (1) and the non-solvated Ce5O(OPri)(13) (3). 1 is rather stable at room-temperature, but desolvation into La5O(OPri)(13) (2), identified by spectroscopy, could be achieved by vacuum treatment. 1 and 3 were structurally characterised by single-crystal X-ray diffraction. In both 1 and 3 the metal atoms have a square pyramidal arrangement. In 1, each crystallographically independent La5O(OPri)(13) (HOPri)(2) molecule contains 3 six-coordinated and 2 seven-coordinated La atoms, while in 3 all Ce atoms are six-coordinated. 3 Is the first structurally characterized example of a purely Ce3+ isopropoxide. Characterisations of 1 and 3 were by IR- and Raman spectroscopy and differential scanning calorimetry, and for 1 also by H-1 and C-13 NMR spectroscopy. The great similarity of the IR spectra of the solid 1 and 3, respectively, to their corresponding solutions, showed that the molecular structure present in the solid state is close to retained in solution.
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