Singlet-Triplet Gaps of Cobalt Nitrosyls: Insights from Tropocoronand Complexes.
Inorg Chem
; 54(15): 7362-7, 2015 Aug 03.
Article
em En
| MEDLINE
| ID: mdl-26203786
ABSTRACT
A density functional theory (DFT) study of {CoNO}(8) cobalt nitrosyl complexes containing the [n,n]tropocoronand ligand (TC-n,n) has revealed a sharp reduction of singlet-triplet gaps as the structures change from near-square-pyramidal (for n = 3) to trigonal-bipyramidal with an equatorial NO (for n = 5, 6). An experimental reinvestigation of [Co(TC-3,3)(NO)] has confirmed that it is not paramagnetic, as originally reported, but diamagnetic, like all other {CoNO}(8) complexes. Furthermore, DFT calculations indicate a substantial singlet-triplet gap of about half an eV or higher for this complex. At the other end of the series, low-energy, thermally accessible triplet states are predicted for [Co(TC-6,6)(NO)]. Enhanced triplet-state reactivity may well provide a partial explanation for the failure to isolate this compound as a stable species.
Texto completo:
1
Base de dados:
MEDLINE
Assunto principal:
Compostos Organometálicos
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Teoria Quântica
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Cobalto
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Compostos Macrocíclicos
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Nitrogênio
Idioma:
En
Ano de publicação:
2015
Tipo de documento:
Article
País de afiliação:
Noruega