title: IR and Raman characterization of the zincocenes (eta(5)-C5Me5)2Zn2 and (eta(5)-C5Me5)(eta(1)-C5Me5)Zn.
abstract: The measured Raman and IR spectra of solid, polycrystalline bis(pentamethylcyclopentadienyl)dizinc, (eta(5)-C5Me5)2Zn2, 1, and bis(pentamethylcyclopentadienyl)monozinc, (eta(5)-C5Me5)(eta(1)-C5Me5)Zn, 8, are reported in some detail. The IR spectra of the vapors of 1 and 8 each trapped in a solid Ar matrix at 12 K confirm the essentially molecular character of the solids. The experimental results have been interpreted with particular reference (i) to the corresponding spectra of (68)Zn-enriched samples of the compounds, and (ii) to the spectra simulated by density functional theory (DFT) calculations at the B3LYP level. The marked differences of structure of 1 and 8 contrast with the relatively close similarity of their vibrational spectra, disparities being revealed only on detailed scrutiny, including the effects of (68)Zn enrichment, and primarily at wavenumbers below 1000 cm(-1). The Zn-Zn stretching motion of 1 features not as a single, well-defined mode identifiable with intense Raman scattering but in several normal modes which respond in varying degrees to (68)Zn substitution. A stretching force constant of 1.42 mdyne A(-1) has been estimated for the Zn-Zn bond of 1.
authors.affiliation: Instituto de Investigaciones Químicas-Departamento de Química Inorgánica, Universidad de Sevilla-Consejo Superior de Investigaciones Científicas, Américo Vespucio 49, 41092 Sevilla, Spain.
authors.forename: Diego
authors.initials: D
authors.lastname: del Rio
authors.forename: Irene
authors.initials: I
authors.lastname: Resa
authors.forename: Amor
authors.initials: A
authors.lastname: Rodriguez
authors.forename: Luis
authors.initials: L
authors.lastname: Sánchez
authors.forename: Ralf
authors.initials: R
authors.lastname: Köppe
authors.forename: Anthony J
authors.initials: AJ
authors.lastname: Downs
authors.forename: Christina Y
authors.initials: CY
authors.lastname: Tang
authors.forename: Ernesto
authors.initials: E
authors.lastname: Carmona
mesh_terms: D003198:Computer Simulation; D008956:Models, Chemical; D009942:Organometallic Compounds / Q000138:chemical synthesis / Q000737:chemistry*; D011789:Quantum Theory; D013055:Spectrophotometry, Infrared / Q000379:methods; D013059:Spectrum Analysis, Raman / Q000379:methods*; D015032:Zinc / Q000737:chemistry*
chemical_list: D009942:Organometallic Compounds; D015032:Zinc