ELECTRON INDUCTIVE PERTURBATION(S) OF HETERONUCLEAR METAL-METAL BONDS- ISOCYANIDE AND INDENYL DERIVATIVES OF THE MIXED-METAL DIMERS [(ETA(5)-C5H5)FE(CO)(2)RE(CO)(5)] AND [MNRE(CO)(10)]

Citation
Pd. Harvey et al., ELECTRON INDUCTIVE PERTURBATION(S) OF HETERONUCLEAR METAL-METAL BONDS- ISOCYANIDE AND INDENYL DERIVATIVES OF THE MIXED-METAL DIMERS [(ETA(5)-C5H5)FE(CO)(2)RE(CO)(5)] AND [MNRE(CO)(10)], Canadian journal of chemistry, 72(10), 1994, pp. 2176-2182
Citations number
29
Categorie Soggetti
Chemistry
ISSN journal
00084042
Volume
72
Issue
10
Year of publication
1994
Pages
2176 - 2182
Database
ISI
SICI code
0008-4042(1994)72:10<2176:EIPOHM>2.0.ZU;2-S
Abstract
The properties of the heteronuclear metal-metal bonds in the unbridged [eta(5)-C5H5)Fe(Co)(2)Re(CO)(5-n)(CNR)(n)] and [(eta(5)-C9H7)Fe(CO)(2 )Re(CO)(5-n)(CNR)(n)] complexes (n = 0, 1, 2; R = tert-butyl (tBu) and 2,6-dimethylphenyl (Xy)) and the two equa torially substituted isomer s of [MnRe(CO)(8)(CN-tBu)(2)] have been investigated theoretically by Extended Huckel Molecular Orbital calculations (EHMO) and experimental ly by UV-visible spectroscopy, electrochemistry, and by microRaman or FT-Raman spectroscopy. The expected d sigma orbital is the lowest uno ccupied molecular orbital (LUMO), mainly fabricated by interactions of the metal d(z2) orbital, but the d pi and d sigma orbitals are the h ighest occupied molecular orbital (HOMO) and HOMO-1, respectively, as demonstrated experimentally from the UV-visible spectra. The EHMO comp utations demonstrate the mixing between these two d pi (and d delta) and d sigma MO orbitals. The influence of substituent effects on the s pectroscopic and electrochemical properties is complicated and is inte rpreted in terms of inductive effects and relative destabilisation of the d sigma, d pi, and d sigma* molecular orbitals. Finally, the meta l-metal stretching frequencies for four mixed metal dimers (MnRe and F eRe) are reported.