An Interesting Behavior and Nonlinear Optical (NLO) Response of Hexamolybdate Metal Cluster: Theoretical Insight into Electro-Optic Modulation of Hybrid Composites

Abstract: Hexamolybdate is a Lindqvist polyoxometalate cluster. Conjugated polymer is covalently bonded with hexamolybdate cluster via side chain. The conjugated polymer containing metal cluster as side-chain pendant has already been investigated for synthesis and optical properties. Herein, the TDDFT calculation were used to investigate the second-order nonlinear optical (NLO) response of a crystal system. A robust wide range of charge-transfer has been observed via donor (metal cluster) towards the acceptor (end organic ring), consequently responsible for the large NLO response of the studied system. This type of charge transfer containing material is considered to be an efficient candidate for NLO applications. However, polymer shows not only efficient charge transfer but also better charge transporting characteristics. The answer whether cluster is donor or acceptor has been explained through DFT calculations. Graphical Abstract: Interestingly, at a specific chain length, the organic ligand (ring) acts as an acceptor while metal cluster behaves like a donor: Clarification by DFT calculations through nonlinear electro-optic modulation.[Figure not available: see fulltext.]