Please use this identifier to cite or link to this item:
|Type:||Artigo de periódico|
|Title:||The Carbonyl Vibration In α-group Iv Metal Ketones|
|Abstract:||Overend and Scherer's perturbation theory treatment (Spectrochim. Acta, 16 (1960) 773) of ν(CO) is applied to R3MCOR′ and R3MCOMR3 (M = C, Si, Ge, Sn). Corrected group frequencies, ν*(CO), which exclude effects extraneous to the CO bond (e.g. molecular geometry and potential energy contributions from internal coordinates other than the CO bond) and which reflect the true strength of the CO bond are calculated. Results are interpreted in terms of Si(dπ)←CO(π) interactions out-weighing silicon's +I inductive effect in lowering ν(CO). Surprisingly, α-metal-CO electronic interactions appear to be of similar magnitude for C, Ge, and Sn. Our conclusions do not contradict the interpretation of the basicity order for the α-metal ketones in terms of relative inductive effects of M since the basicities depend on the availability of the non-bonding σ electrons of oxygen. In fact, the greater +I of silicon may be expected to promote more effective (d-p)π back-donation. A comment concerning the CO vibration in β-silyl ketones is given. © 1973.|
|Appears in Collections:||Unicamp - Artigos e Outros Documentos|
Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.