Vibrational spectra of penta-atomic silicon–carbon clusters. III. Pentagonal Si3C2

Abstract

Articles you may be interested inElectronic structure of diatomic boron nitride Fourier transform infrared measurements on the spectra of the products of the vaporization of silicon/carbon mixtures trapped in argon at ϳ10 K combined with the results from a published ab initio study and from new theoretical calculations carried out in the present work, have resulted in the first observation of a spectrum for the pentagonal Si 3 C 2 cluster. Three vibrational fundamentals have been assigned: the 2 ͑a 1 ͒ symmetric ''breathing'' vibration at 681.1 cm Ϫ1 , the 7 ͑b 2 ͒ Si ␣ -C-C-Si ␣ stretching deformation at 956.7 cm Ϫ1 , and the 8 ͑b 2 ͒ C-Si ␤ -C antisymmetric stretching vibration at 597.8 cm Ϫ1 . The observed frequencies, relative intensities, and 13 C, 29 Si, and 30 Si isotopic shifts are in excellent agreement with the theoretical predictions.

Fourier transform infrared observation of the ν1(σ) mode of linear SiCH in Ar at 10 K

“…It has often been possible to observe 29 Si and 30 Si isotopic shifts in their respective, 4.7% and 3.1% natural abundances in the spectra of silicon-carbon clusters produced by high temperature evaporation, [13][14][15][16] but the relatively weak absorption lines in the present spectra obtained by VUV photolysis make this problematic, even though the predicted 29,30 Si isotopic shifts are large enough to move them outside the envelope of the fundamental absorptions. Nevertheless, because there is no evidence of the vibrational spectra of containing two ͑e.g., Si 2 C 13 and Si 2 C 2 ͒, 14 or more Si atoms ͓e.g., Si 3 C ͑Ref.…”

Fourier transform infrared identification of the ν5(σ u) fundamental of SiC5Si

“…This criterion was established empirically via previous Si m C n assignments by this lab. 4,7,8,[19][20][21][22][23][24][25] …”

Vibrational spectra and structures of SinC clusters (n = 3–8)

“…With Fouriertransform infrared spectroscopy in Ar matrices combined with quantum chemical calculations, the molecular structures of small Si n C m (n + m r 5) clusters were determined, e.g., a linear centrosymmetric geometry for Si 2 C 3 and a rhomboidal C 2v structure for Si 3 C. [35][36][37][38] Furthermore, Si 3 C 2 is a pentagon, and Si 2 C 4 has a linear symmetric geometry in the ground state. 39 Similarly, C-rich clusters such as SiC 4 , SiC 5 , SiC 7 , and SiC 9 , were found to exhibit chain-like structures. 38,[40][41][42][43] For small Si n C m clusters with n + m r 4, the electronic structure has been studied by resonant photoionization.…”