Crystal and molecular structures of diphenylethylarsine sulfide, C14H15AsS, and p-tolyldiethylarsine sulfide, C11H17AsS

In order to elucidate the influence of aryl or alkyl substituents on the nature of the ⋯ bond, which controls the complexing properties of the substances (Alk)n(Ar)3-nAsS (n = 0–3), the X-ray investigation of (p-MeC6H4)Et3AsS (TDEAS) and Ph2EtAsS (DPEAS) has been carried out. It was shown that the bond length AsS in these compounds has intermediate values (2.0896 and 2.0812 A) in respect to those previously found by us in Et3AsS and Ph3AsS (2.115 and 2.077 A). This confirms the conclusion that the increase of the number of aryl substituents in tertiary arsine sulfides leads to a decrease of electron density on the As atom along with simultaneous strengthening of the π-interaction between As and S.