Theoretical study of the impact factor on redox property and second-order nonlinear response for organoimido derivatives of [Mo6O19]2−: Electron donors with magnitude of conjugated groups or length of conjugated chain

Mono- and multi-organoimido substituted derivatives for Lindqvist-type molybdate were carried out to search the preferred contribution factor on the redox property and the second-order nonlinear optical response. It was indicated that organic conjugated groups were much more sensitive to the redox property and nonlinear optical response than non-conjugated ones. The increment of NAr ligands, i.e. the greater net charge donation between organic segment and inorganic polyanion cluster, drove the first reduction potential dramatically negative. In contrast, the lengthening of conjugated chain resulted in remarkable improvement on second-order nonlinear optical response than in reduction potentials. In addition, MoN in mono-organoimido substituted derivatives has localized the electrons for HOMO on π-orbital of the first phenyl ring adjacent to N1 together with small part of π-pd orbital between Mo1 and N1, and the electron transition tends to transfer to organic conjugated groups. The two distinct paths may offer favorable direction for experiment.