Exploration of 1-Arylmethyl-1,3-diphosphacyclobutane-2,4-diyls as Hole Transfer Materials

This paper describes the p type semiconductor characteristics of 1-arylmethyl-substituted air-tolerant 1,3-diphosphacyclobutane-2,4-diyls, focusing preliminarily on their hole transfer parameters deduced from their crystal and density functional theory (DFT) structures. 1-(2-Anthrylmethy)-3-t-butyl-2,4-bis (2,4,6-tri-t-butylphenyl)-1,3-diphosphacyclobutane-2,4-diyl functions as a p-type field-effect transistor (FET) with semiconductor parameters comparable to its benzyl-substituted derivative. Thienylmethyl groups induced the FET response, and thus we investigated the utility of the 2-thieno[3,2-b] thio-phenemethyl group. Critical parameters, including reorganization energies (lambda), hole couplings (V), and hole hopping rates (W) were estimated based on experimental and DFT data. The benzyl and 2-anthrylmethy groups constructed hole transfer pathways comparable to that of acenes, whereas the 2-thieno [3,2-b] thiophenemethyl substituent resulted in the assembly of a unique three-dimensional network. The findings described in this study may lead to the fabrication of superior FET devices based on the chemistry of 1,3-diphosphacyclobutane-2,4-diyl.