Vibrational absorption spectra of C_nS (n = 2, 6) and C_nS₂ (n = 7, 9, 11, 13, 15) linear carbon–sulfur clusters

Abstract

Carbon-sulfur clusters have been generated by the laser ablation of mixed sulfur-graphite pellets and the pulsed-jet discharge of acetylene/carbon disulfide/argon or diacetylene/carbon disulfide/argon mixtures. Fourier transform infrared absorption spectroscopic measurements of cryogenic argon matrices, aided by Becke's three-parameter exchange functional and the gradient-corrected functional of Lee, Yang, and Paar (B3LYP/6-311G*) calculations of the previous paper, has led to the identification of six heretofore unknown C n S m clusters: C 6 S, C 7 S 2 , C 9 S 2 , C 11 S 2 , C 13 S 2 , and C 15 S 2 . In addition, C 2 S has also been formed and bands at 1662.6 and 857.2 cm Ϫ1 unambiguously assigned to its C-C and C-S stretching modes, respectively. Using 12 C/ 13 C isotopic substitution and density functional theory calculations, bands at 1377.9, 1368.8, 1832.4, and 1796.9 cm Ϫ1 have been assigned to the 4 , 7 , 10 , and 12 C-C stretching vibrations in linear C 6 S, C 7 S 2 , C 13 S 2 , and C 15 S 2 clusters, respectively. From intensity correlation measurements, the 2056.7, 1938.2, and 1504.5 cm Ϫ1 bands have been attributed to the C 7 S 2 ( 5 , 6 ), and C 15 S 2 ( 13 ) clusters, respectively. A "coincidence plot" has been used to ascribe several additional bands to the C 9 S 2 ( 7 , 8 ), and C 11 S 2 ( 9 ) clusters.

Carbon–sulfur chains: A high‐resolution infrared and quantum‐chemical study of C3S and SC7S

“…However, in an argon matrix the ν 5 mode of SC 7 S has been observed (tentatively) at 2056.7 cm −1 (Ref. ) which is fully compatible with the gas‐phase location at 2061 cm −1 in Figure . For comparison, a redshift of a few cm −1 is of similar order as that observed for pure carbon chains of similar size: 2127.8 cm −1 (Ar) versus 2138.315 cm −1 (gas) for the ν 4 mode of C 7 and 2078.1 cm −1 (Ar) versus 2079.67 cm −1 (gas) for the ν 5 mode of C 9 (see Ref.…”

“… and references therein), matrix‐isolation infrared spectroscopy (Ref. and references therein), as well as microwave spectroscopy (Refs. and references therein).…”

Parity alternation of linear ground-state CnS2− (n=6–18) clusters

“…For a particular family of molecules, the basic struc- ture with the lowest energy affects the "building up" of larger molecules, and this is an important area in biochemical research. In previous theoretical investigations on C n S, C n S + , and C n S − clusters, a configuration with the sulfur atom located at the terminus of a linear carbon chain is probably the most favorable in energy [12][13][14][15][16]18,19]. The most stable structures of C n S 2 are also suggested to be linear with one sulfur atom located at each end of the carbon chain [12,13,17].…”

“…In previous theoretical investigations on C n S, C n S + , and C n S − clusters, a configuration with the sulfur atom located at the terminus of a linear carbon chain is probably the most favorable in energy [12][13][14][15][16]18,19]. The most stable structures of C n S 2 are also suggested to be linear with one sulfur atom located at each end of the carbon chain [12,13,17]. After comparing a great number of models, we find that the "ground-state" isomers of C n S 2− (n = 6-18) clusters are linear in configuration having a sulfur atom at a terminal position.…”

“…Zaidi et al calculated the most stable linear isomer of C 3 S in potential energy surface by CCSD(T) method [11]. Wang et al calculated infrared spectra and dissociation pathways of linear C n S m (n = 1-29, m = 1-2) clusters and vibrational absorption spectra of C n S (n = 2, 6) and C n S 2 (n = 7,9,11,13,15) linear carbon-sulfur clusters using B3LYP/6-311G * DFT methods [12,13]. Pérez-Juste et al examined linear sulfur-carbon chains C n S (n = 1-6) of astronomical interest by means of several theoretical methods [14].…”