Electronic Absorption Spectra of C₄O^- and C₄S^- in Neon Matrixes

Abstract

The electronic spectra of the anions C 4 Oand C 4 Shave been observed by absorption spectroscopy in a neon matrix using mass selection. The symmetries of the states are determined on the basis of spectroscopic evidence and ab initio calculations. Two absorption systems of C 4 Oare assigned to the A 2 Σ + r X 2 Π and B 2 Π r X 2 Π electronic transitions, with band origins near 875 and 442 nm, respectively. The B 2 Π r X 2 Π system of C 4 S -, with the origin near 568 nm, has also been observed. After photobleaching, the 3 Σr X 3 Σelectronic transition of C 4 S is observed around 447 nm.

Neutral cumulene oxide CCCCO is accessible by one-electron oxidation of [CCCCO]−˙ in the gas phase

“…The results agree well with those obtained in previous studies. 28- 32 For example, the electron affinity for triplet CCCCO is calculated to be 2.86 eV [at the CCSD(T)/aug-cc-pVDZ//B3LYP/6-31G* level of theory], and this value should be compared with 2.83 eV at the CCSD/aug-cc-pVDZ level of theory. 31 Both singlet and triplet CCCCO are very similar in structure, and are best represented by the cumulene oxide structure C=C=C=C=O.…”

“…Theory predicts that it has a 2 P electronic state, 28,31 confirmed by its absorption spectrum in a neon matrix. 32 It is reported that this anion may be formed by the reaction of C 4 − • with oxygen. 37 However, this synthesis does not absolutely prove the bond connectivity of the product anion and as such is not suitable for this study.…”

Electronic absorption spectra of C7O and C7O+ in 6 K neon matrices

“…Only the electronic transition of C 2 O in the gas phase [18], and of the two C 2 O − and C 4 O − anions in 6 K neon matrices, have been reported [19,20]. There are a few theoretical papers on the excitation energies of C 2 O, C 2 O − , C 4 O − and C 2 O + [20][21][22][23].…”

Photoelectron spectroscopy and density functional calculations of CnSm− (n = 2–7; m = 1, 2) clusters

“…It would be interesting to compare the structures of C n S m (m = 1, 2) clusters with their isoelectronic counterparts such as C n O m and Si n S m (m = 1, 2) clusters which were investigated previously by a number of experiments and theoretical calculations. The most stable structures of the neutral C n O (n r 9) [48][49][50][51] and C n O 2 (n = 2-7) [52][53][54][55][56][57][58][59] clusters reported in the literature are similar to those of corresponding neutral C n S and C n S 2 , they are all linear configurations with a carbon chain C n terminated either by the O/S atom at one end or at both ends. This is because that the oxygen atom and the sulfur atom have similar bonding characteristics.…”