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Titolo:
EXTENDED X-RAY-ABSORPTION FINE-STRUCTURE, CRYSTAL-STRUCTURES AT 295-KAND 173-K, AND ELECTRON-PARAMAGNETIC-RESONANCE AND ELECTRONIC-SPECTRAOF BIS[TRIS(2-PYRIDYL)METHANE]COPPER(II) DINITRATE
Autore:
ASTLEY T; ELLIS PJ; FREEMAN HC; HITCHMAN MA; KEENE FR; TIEKINK ERT;
Indirizzi:
UNIV SYDNEY,DEPT INORGAN CHEM SYDNEY NSW 2006 AUSTRALIA UNIV SYDNEY,DEPT INORGAN CHEM SYDNEY NSW 2006 AUSTRALIA JAMES COOK UNIV N QUEENSLAND,DEPT MOLEC SCI TOWNSVILLE QLD 4811 AUSTRALIA UNIV TASMANIA,DEPT CHEM HOBART TAS 7000 AUSTRALIA UNIV ADELAIDE,DEPT CHEM ADELAIDE SA 5005 AUSTRALIA
Titolo Testata:
Journal of the Chemical Society. Dalton transactions
fascicolo: 4, , anno: 1995,
pagine: 595 - 601
SICI:
0300-9246(1995):4<595:EXFCA2>2.0.ZU;2-W
Fonte:
ISI
Lingua:
ENG
Soggetto:
JAHN-TELLER DISTORTIONS; PYRAZOLE-DERIVED LIGANDS; COORDINATION CHEMISTRY; ANGULAR-OVERLAP; COMPLEXES; TRIS(2-PYRIDYL)PHOSPHINE; TRIS(2-PYRIDYL)METHANE; REDETERMINATION; COPPER(II); DEPENDENCE;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Science Citation Index Expanded
Citazioni:
36
Recensione:
Indirizzi per estratti:
Citazione:
T. Astley et al., "EXTENDED X-RAY-ABSORPTION FINE-STRUCTURE, CRYSTAL-STRUCTURES AT 295-KAND 173-K, AND ELECTRON-PARAMAGNETIC-RESONANCE AND ELECTRONIC-SPECTRAOF BIS[TRIS(2-PYRIDYL)METHANE]COPPER(II) DINITRATE", Journal of the Chemical Society. Dalton transactions, (4), 1995, pp. 595-601

Abstract

The crystal structure of bis[tris(2-pyridyl)methane]copper(II) dinitrate, [Cu{(C5H4N)3CH}2][NO3]2 has been determined. At 295 K the Cu atomlies on a special position so that all six Cu-N bonds are crystallographically equivalent [Cu-N 2.103(4) angstrom]. The structure at 173 K is very similar [Cu-N 2.095(3) angstrom]. However, the electronic spectrum suggests that the Cu2+ ion experiences a ligand field of tetragonal symmetry. This has been confirmed by the EXAFS of the compound, which shows four nitrogen atoms at 2.04 angstrom and two at 2.25 angstromfrom the copper. The apparent trigonal symmetry revealed by the X-rayanalysis is thus due to disorder of the long and short Cu-N bonds about the three-fold axis. The EPR spectrum shows an isotropic signal at 295 K, but a signal characteristic of a tetragonally elongated octahedral complex at 150 K. This suggests that the directions of the long and short bonds interchange rapidly on the EPR time-scale at room temperature, but that the complexes become frozen into particular orientations on cooling.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 01/12/20 alle ore 08:17:09