Structure, bonding, aromaticity and reactivity of Roesky's sulfoxide

Abstract

The molecular and crystal structure of 1-oxo-1,2,4,3,5-trithiadiazole () has been studied experimentally by the determination of the crystal structure and theoretically at the DFT/B1B95/aug-cc-pVTZ level of theory. The combination of the geometrical data with a number of properties of the title compound, consisting of orbital topologies, Hirshfeld charges and bond orders, aromaticity parameters and Fukui functions, led to a description of its structure, aromaticity and reactivity. In addition, the nature of the long sulfur-sulfur bond has been investigated. The bands in newly recorded infrared and Raman spectra have been assigned to the normal vibrations of the molecule, based on calculated vibrational data. The results of theoretical calculations of the 14N NMR chemical shifts have been compared to the experimentally obtained shifts.

Molecular and Crystal Structures of Cp*M(S2N2) (M = Co, Rh, Ir) and Related Compounds

“…Thanks to the development of new approaches within density-functional theory (DFT) in the early 2000s, it has become possible to study more advanced systems containing heavier elements. [7][8][9][10] Since then, we focused our attention on sulfur-nitrogen ring compounds and we found suitable DFT methodologies which led to successful descriptions of Roesky's sulfoxide (S 3 N 2 O), [11] Roesky's ketone [(S 2 N 2 )-CO] [12] and other ring compounds bearing the -SNSNfragment. [13] Experience from previous work combined with the advantage of the use of hybrid functionals enabled us to perform a detailed study on 1 with the emphasis on the geometry of the molecule, its bonding, aromaticity, and reactivity.…”

Five-Membered Arsenic−Sulfur−Nitrogen Heterocycles, RAs(S2N2) (R = Me, Et,iPr,tBu, Ph, Mes)

“…These peaks were observed in none of the spectra of the starting materials and are most likely due to the As(S 2 N 2 ) ring vibrational modes (Tables S3-S8 25,26,29 The As-N stretch gives IR bands around 585 cm -1 and the As-S stretches in cyclic molecules and cages range from 390 to 329 cm -1 . 30,31 The deformation vibrations of all the above mentioned bonds are scattered over the remaining low-frequency region.…”

“…The  increase in the spectra of 6 with respect to 5 is particularly noteworthy and can be explained by significant structural differences of the two compounds as determined by X-ray analysis. Since arsenic is a main group element and since the 14 N NMR chemical shifts are similar to those measured for Roesky's ketone and sulfoxide, 25,26 we assigned the lower chemical shift to the arsenic-bound nitrogen and the higher chemical shift to the SNS nitrogen.…”

“…34 Elongation of the bond between the terminal sulfur of the (S 2 N 2 ) moiety and the fifth element bound to this moiety has been observed in other five-membered main group sulfur-nitrogen heterocycles such as Roesky's ketone or Roesky's sulfoxide. 26,35 Table 2. Selected bond lengths (Å) and angles (º) of 5 and 6 5 6 a for a trigonal planar coordination, which supports the formal Lewis formula of 5.…”

“…The S(2)-As(1)-N(1) right angle corresponds well with the trend of inverse proportionality between van der Waals' radius of an atom and a bond angle value at this atom in five-membered sulfur-nitrogen rings. 14,22,26,35,39 The unit cell contains in total two molecules of 5, of which only one forms the asymmetric unit.…”