Electronic Spectra and Structure of Sulfur Compounds

Abstract

The lower-energy electronic states of a series of saturated sulfur compounds have been investigated theoretically and experimentally. The compounds investigated fell into two categories: the monosulfide series ABS in which the substituents A and B were varied, and the polysulfide series R2Sn, where n=1, 2, 3, and 4 and where R was usually CH3. The data collected included ultraviolet vapor spectra, solution spectra, solvent shifts, and vibrational data. Computations followed an approach related to that of Wolfsberg and Helmholz. This theoretical method closely approximates the experimentally observed energies in the compounds containing a single sulfur atom but encounters difficulties when two or more sulfurs are present because of the large 3dS−3dS and 4sS−4sS interactions which are predicted. It is indicated that the lower-energy excited electronic states of all the monosulfide compounds investigated are of a molecular nature in which the 4sS and 3dS atomic orbitals of sulfur play particularly dominant but by no means exclusive roles. The lower-energy excited states of the molecules R2Sn, n=2, 3, and 4, also contain significant 4s and 3d character; additionally, however, they are of S–S antibonding nature.

A CASSCF/CASPT2 study on the low‐lying electronic states of the CH3SS and its cation

“…I n the past two decades, numerous experimental and theoretical studies on photodissociation of Dimethyl disulphide, CH 3 SSCH 3 , and they presented abundant information [1][2][3][4][5][6][7][8][9][10]. All these experimental and theoretical details confirmed that CH 3 S and CH 3 S 2 are the products of the photodissociation.…”

Ab initio study of the ground and excited states of hydrogen sulphide using SCF and CI calculations

“…Theoretical assignments of this region of the spectrum by semiempirical and ab initio techniques have proved inconclusive. Approximate studies by Thompson et al [14] predict a low-lying transition to a sulphur 3d orbital, while Murrell et al [15] calculate the presence of a transition to a Rydberg 4s orbital together with two valence-shell transitions in the 5.0-7.4 eV M.P.…”

“…In common with previous theoretical studies of H2S conducted at the SCF level [8][9][10][11], recent valence bond [12] and coupled electron pair (CEPA) and pair natural orbital configuration interaction (PNO-CI) [13] studies have been mainly confined to the ground state of the neutral molecule. Studies of the low-lying excited states have in general relied on less sophisticated calculations [14][15][16][17][18][19].…”

(Anthracen-9-yl)methyl sulfides as a mechanistic probe for chemical as well as photochemical electron-transfer reactions

“…It is reported that organic sulfides are ideal precursors for sulfur-centred radical cations that can be used for probing mechanisms of electron-transfer quenching of excited states as well as for monitoring the fate of sulfur radicals. [3][4][5][6][7][8][9][10][11] One of the most frequently used reagents for the oxidative generation of radicals is the strong one-electron oxidant cerium(IV) ammonium nitrate (CAN). CAN has been widely used in organic reactions which include oxidation, [12][13][14][15][16] oxidative addition, [17][18][19][20][21] photooxidation, 22 nitration, [23][24][25] deprotection, 26,27 graft polymerization, 28,29 etc.…”