A computational study of neutral and charged pyrroles. Functionalization of 1-phenylpyrrole and 2,5-dimethyl-1-phenylpyrrole with electron donating methylsulfanyl groups

We present a detailed computational study of the geometric structure and to rsional potential of 1-phenylpyrrole, 2,5-dimethyl-1-phenylpyrrole. 3.4-bis (methylsulfanyl)-1-phenylpyrrole, and 3,4-bis(methylsulfanyl)-2,5-dimethyl- 1-phenylpyrrole. Both the neutral molecule and the corresponding radical c ation are investigated for each compound. Calculations of the neutral speci es and radical cations are performed at the RHF/6-31G(d) and UHF/6-31G(d) l evels, respectively, Our study has two major aims: (i) to assess and evalua te the effects of the bulky methyl substituents at 2,5 positions and (ii) t o investigate the effects exerted by the electron-donating methylsulfanyl g roups. The analysis of the results has revealed that both the methyl and me thylsulfanyl substituents induce unusual structural properties, particularl y in the radical cations.