Low temperature Raman study of bis(trimethylsilyl)acetylene

Abstract

Raman spectra of acetylacetone were recorded for molecules isolated in an argon matrix at 10 K and for a polycrystalline sample. In the solid sample, broad bands appear superimposed on a much weaker Raman spectrum corresponding mainly to the stable enol form. The position of these bands depends on the excitation wavelength (514.5 and 488.8 nm argon ion laser lines were used), sample temperature, and cooling history. They are attributed to transitions from an excited electronic state to various isomer states in the ground electronic state. Laser photons have energies comparable to energies of a number of excited triplet states predicted for a free acetylacetone molecule (Chen, X. Chem. Phys. 2002, 116, 5694). Using matrix isolation in argon, the vibrational spectrum of acetylacetone at 10 K was recorded. Strong bands at 1602 and 1629 cm -1 are assigned as the SYN enol bands, while a weaker underlying band at 1687 cm -1 and a medium shoulder at 1617 cm -1 are assigned as TS2 enol bands.

Redox Communication between Two Diarylamido/Bis(phosphine) (PNP)M Moieties Bridged by Ynediyl Linkers (M = Ni, Pd, Pt)

“…Raman spectra of 3M also support the same trend. Notably, CC triple-bond stretchings observed in 3M were considerably lower in comparison to those of bis­(trimethylsilyl)­acetylene (2108 cm –1 ) and bis­(diphenylphosphino)­acetylene (2097 cm –1 ) …”