Deformation-density studies of thiathiophthenes. II. 2,4-diphenyl-6a-thiathiophthene

Topological analysis of charge density in heptasulfur imide (S7NH) from isolated molecule to solid

“…Some studies of experimental deformation density distribution reveal various density distribution on S-S bond, such that a double maximum was found along the S-S bond of S 8 molecule [1]; a maximum at the midpoint of the S-S bonds was observed on Na 2 S 2 O 6 $ 2H 2 O, Na 2 S 2 O 6 $2D 2 O [S-SZ2.14 Å ] and MgS 2 O 3 $6H 2 O [S-SZ2.02 Å ] [2][3]. Several thiathiophthene derivatives were investigated, little density accumulation was detected in the deformation density distribution along the S-S bonds [S-SZ2.14-2.51 Å ] [5][6][7][8][9][10][11][12]. The similar results were also reproduced from theoretical studies [13].…”

“…The studies of molecules containing sulfur-sulfur bonds have drawn extensive attention in the past 20 years [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20] not only on the bonding features of S-S bond and the necessity for the inclusion of d-polarization functions for the sulfur atoms, but also for its important role in the protein folding. Some studies of experimental deformation density distribution reveal various density distribution on S-S bond, such that a double maximum was found along the S-S bond of S 8 molecule [1]; a maximum at the midpoint of the S-S bonds was observed on Na 2 S 2 O 6 $ 2H 2 O, Na 2 S 2 O 6 $2D 2 O [S-SZ2.14 Å ] and MgS 2 O 3 $6H 2 O [S-SZ2.02 Å ] [2][3].…”

Bond Characterization of a Unique Thiathiophthene Derivative: Combined Charge Density Study and X-ray Absorption Spectroscopy

“…Because of such interesting bonding character, charge density studies have been applied to quite a few S-related compounds, − ,, including the thiathiophthene (TTP) derivatives. − There are many TTP derivatives: some are symmetric with equal S–S bonds when the substituents are at the 2,5-positions; ,, others are asymmetric with a long and a short S–S bond when the substituents are at 2,4-positions. ,− The title compound, 2,5-dimethyl-3,4-trimethylene-6a-TTP, belongs to a symmetric one. It was indicated , that the Lewis resonance structures of TTP could be represented as in Figure , where the structure was described as a 10π electron aromatic system , plus a 3c-4e σ bond along S–S–S.…”

“…It was indicated , that the Lewis resonance structures of TTP could be represented as in Figure , where the structure was described as a 10π electron aromatic system , plus a 3c-4e σ bond along S–S–S. The deformation density of two TTP derivatives, one symmetric, 2,5-dimethyl-TTP, and the other asymmetric, 2,4-diphenyl-TTP, was investigated. − The S–S bond lengths of these compounds are all longer than the corresponding S–S single bond. The aim of this study is to establish the bond characterization on the title molecule through a combined experimental and theoretical charge density distribution as well as sulfur K-edge X-ray absorption spectroscopy (XAS).…”

Deformation density studies of thiathiophthene. 3. Theoretical studies on 2,5-dimethylthiathiophthene and 2,4-diphenylthiathiophthene

“…The enhancement of the density accumulation along S-C bonds by the inclusion of sulfur d polarization functions is more prominent than the region around the sulfur atom. The improvements of the deformation density based on split valence level ab initio calculation in comparison with the one based on EHMO calculations4 (Figure3in ref4)…”