Towards Understanding the Reactivity and Optical Properties of Organosilicon Sulfide Clusters

We report the extension of the class of organotetrel sulfide clusters with further examples of the still rare silicon-based species, synthesized from RSiCl3 with R=phenyl (Ph, I), naphthyl (Np, II), and styryl (Sty, III) with Na2S. Besides known [(PhSi)(4)S-6] (IV), new compounds [(NpSi)(4)S-6] (1) and [(StySi)(4)S-6] (2) were obtained, the first two of which underwent reactions with [AuCl(PPh3)] to form ternary complexes. DFT studies of cluster dimers helped us understand the differences between the habit of {Si4S6}- and {Sn4S6}-based compounds. Crystalline 1 showed a pronounced nonlinear optical response, while for intrinsically amorphous 2, the chemical damage threshold seems to inhibit a corresponding observation. Calculations within the independent particle approximation served to rationalize and compare electronic and optical excitations of [(RSi)(4)S-6] clusters (R=Ph, Np). The calculations reproduced the measured data and allowed for the interpretation of the main spectroscopic features.

Automated summary

This study reports the extension of organotetrel sulfide clusters with new silicon-based compounds, synthesized and studied for their optical and electronic properties. DFT calculations and experimental data validation provided insights into the optical characteristics of the new compounds.