| 1. |
- Gowda, Vasantha, et al.
(författare)
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Structural investigations of rare earth dialkyl dithiocarbamate complexes: solid-state NMR, X-ray diffraction and DFT calculation studies
- 2013
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- In this study, we made an attempt to qualitatively study the structures of few rare earth metal complexes by employing solid state NMR, X-Ray Diffraction, and preliminary DFT calculations. High resolution 13C and 15N solid state CP/MAS NMR spectra were recorded for six diamagnetic polycrystalline rare earth dialkyldithiocarbamates of the general formula [(RE2S2CNR2)3 PHEN] (where RE=La or Y, R=C2H5, C3H7, and i-C3H7) [1]. Different isotropic 13C and 15N chemical shifts for the three dialkyldithiocarbamato groups were observed. Regulacio et al. (2005) inferred that irrespective of the alkyl chains, rare earth complexes of dialkyldithiocarbamates and phenanthroline (3:1) ligands always crystallize in a monoclinic system with a space P21/c group. However, comparative analysis of solid state 13C/15N CPMAS spectra of polycrystalline yttrium and lanthanum diethyldithiocarbamate complexes shows the presence of significant differences, indicating structural variations of these complexes. Also, quite different X-Ray diffraction powder pattern was observed for the above two complexes. Finally, the computational geometry optimization of Y and La complexes, followed by the preliminary calculation of 13C and 15N chemical shifts and shielding contributions with the ADF program [2], found to be very near to the experimental results.
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| 2. |
- Roukala, Juho, et al.
(författare)
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Experimental and First-Principles NMR Analysis of Pt(II) Complexes With O,O'-Dialkyldithiophosphate Ligands
- 2016
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Ingår i: Journal of Physical Chemistry A. - : American Chemical Society (ACS). - 1089-5639 .- 1520-5215. ; 120:42, s. 8326-8338
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Tidskriftsartikel (refereegranskat)abstract
- Polycrystalline bis(dialkyldithiophosphato)Pt(II) complexes of the form [Pt{S2P(OR)2}2] (R = ethyl, iso-propyl, iso-butyl, sec-butyl or cyclo-hexyl group) were studied using solid-state 31P and 195Pt NMR spectroscopy, to determine the influence of R to the structure of the central chromophore. The measured anisotropic chemical shift (CS) parameters for 31P and 195Pt afford more detailed chemical and structural information, as compared to isotropic CS and J couplings alone. Advanced theoretical modeling at the hybrid DFT level, including both crystal lattice and the important relativistic spin-orbit effects qualitatively reproduced the measured CS tensors, supported the experimental analysis, and provided extensive orientational information. A particular correction model for the non-negligible lattice effects was adopted, allowing one to avoid a severe deterioration of the 195Pt anisotropic parameters due to the high requirements posed on the pseudopotential quality in such calculations. Though negligible differences were found between the 195Pt CS tensors with different substituents R, the 31P CS parameters differed significantly between the complexes, implying the potential to distinguish between them. The presented approach enables good resolution and a detailed analysis of heavy-element compounds by solid-state NMR, thus widening the understanding of such systems.
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| 3. |
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| 4. |
- Frantti, J., Ivanov,S. A., Eriksson, .S- G. Rundlöf, H. Lantto, V. Lappalainen, J. and Kakihana, M.
(författare)
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High resolution neutron powder diffraction study of the microstrain contributions in Pb(ZrxTi1
- 2002
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Ingår i: Proceeding at the Electroceramics VIII Conference, August 25-28 2002, Rome, Italy.
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)
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| 5. |
- Frantti, J., Ivanov, S. A., Eriksson, S.- G., Rundlöf, H., Lantto,V.Lappalainen, J. and Kakihana, M.
(författare)
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On the phase transitions of Pb(ZrxTi1
- 2002
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Ingår i: Phys. Rev.. ; B66, s. 64108-
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Tidskriftsartikel (refereegranskat)
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| 6. |
- Frantti, J., Ivanov, S., Eriksson, S.- G., Lappalainen, J., Lantto, V. and Kakihana, M.
(författare)
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Neutron Diffraction and Bond-valence Calulation studies of Pb(ZrxTi1
- 2002
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Ingår i: Ferroelectrics. ; 272, s. 51-
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Tidskriftsartikel (refereegranskat)
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| 7. |
- Frantti, J., Ivanov, S., Eriksson, S., Rundlöf, H., Lantto, V., Lappalainen, J. and Kakihana, M.
(författare)
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Phase transitions of Pb(ZrxTi1
- 2002
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Ingår i: Phys. Rev.. ; B66, s. 64108-
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Tidskriftsartikel (refereegranskat)
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| 8. |
- Frantti, J., Ivanov S., Lappalainen, J., Eriksson, S., Lantto, V., Nishio, S., Kakihana, M. and Rundlöf, H.
(författare)
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Local and average structure of lead titanate based ceramics
- 2002
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Ingår i: Ferroelectrics. ; 266, s. 73-
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Tidskriftsartikel (refereegranskat)
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| 9. |
- Frantti, J, et al.
(författare)
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Local and average structure of lead titanate based ceramics
- 2002
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Ingår i: Ferroelectrics. - : Informa UK Limited. - 0015-0193 .- 1563-5112. ; 266:1, s. 73-90
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Tidskriftsartikel (refereegranskat)abstract
- The revised lattice dynamics of Pb(Zr x Ti 1 -x )O 3 (PZT) with 0.10 ≤ x ≤0.54 ceramics is reported. The phase transition from tetragonal phase to the monoclinic phase is proposed to occur via locally distorted regions. Neutron diffraction data suggests that these local regions transform to the monoclinic phase with decreasing temperature, when x ≈0.50.
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| 10. |
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