Insightful understanding of charge transfer processes in metalated phthalocyanines

Marcus electron transfer theory coupling with quantum-mechanics (QM) calculations was applied to study the hole mobilities of a series of metalated phthalocyanine molecular crystals. The effect of metals on the frontier occupied molecular orbitals is discussed according to their eigenvalues and distributions. Temperature-dependent mobilities are rationalized by considering intermolecular interactions. Our results reveal that the central metal atoms have limited impacts on the properties of phthalocyanines. This discovery is demonstrated by their almost identical distributions and energy order of the highest occupied molecular orbitals of phthalocyanine compounds and slightly deceased internal reorganization energy and increased electron coupling compared with those of metal-free phthalocyanine. Our results reveal that the weak intermolecular interaction is mainly responsible for the notable temperature-dependent conductivity. The findings of this paper are expected to benefit the molecular design of novel phthalocyanine-based electronic devices.