A RESONANCE RAMAN SPECTROELECTROCHEMICAL STUDY OF THE ZN(II) TETRAPHENYLCHLORIN ANION

Authors
BLACKWOOD ME LIN CY CLEARY SR MCGLASHEN MM SPIRO TG
Citation
Me. Blackwood et al., A RESONANCE RAMAN SPECTROELECTROCHEMICAL STUDY OF THE ZN(II) TETRAPHENYLCHLORIN ANION, The journal of physical chemistry. A, Molecules, spectroscopy, kinetics, environment, & general theory, 101(3), 1997, pp. 255-258
Citations number
37
Categorie Soggetti
Chemistry Physical
Journal title
The journal of physical chemistry. A, Molecules, spectroscopy, kinetics, environment, & general theory → ACNP
ISSN journal
10895639
Volume
101
Issue
3
Year of publication
1997
Pages
255 - 258
Database
ISI
SICI code
1089-5639(1997)101:3<255:ARRSSO>2.0.ZU;2-A
Abstract
Zinc(II) tetraphenylchlorin (ZnTPC) and its pi-anion radical have been studied by UV-vis absorption and resonance Raman (RR) spectroscopies. Analyses of the RR spectra were aided by data for the pyrrole-d(8), m eso-C-13, and phenyl-d(20) isotopomers. Upon formation of the anion, s ignificant frequency shifts are observed in skeletal vibrational modes , while substituent modes remain essentially unshifted. Both frequency upshifts (nu(37), nu(10), and nu(19)) and downshifts (nu(2), nu(11), and nu(3)) occur for the C-alpha C-m and CbetaCbeta stretching modes i n the pi-anion. Modes involving significant CalphaCbeta stretching mot ion, nu(4) and nu(41), upshift in the anion spectrum. The pattern of v ibrational frequency shifts for the anion of ZnTPC is similar to what is observed for the anion of vanadyl tetraphenylporphyrin ((VO)TPP) de spite the reduction of a pyrrole ring in TPC. This resemblance is due to the Jahn-Teller distortion in (VO)TPP-, which gives its singly occu pied molecular orbital the same bonding pattern as in ZnTPC-.