Quantum chemical design of triple hybrid organic, inorganic and organometallic materials: An efficient two-dimensional second-order nonlinear optical material

In the present report, a quantum chemical study is presented through the designing of triple hybrid nonlinear optical (NLO) materials comprising of organic, inorganic and organometallic moieties. The designed compounds possess two-dimensional (2-D) NLO properties with significantly larger values of their nonlinear anisotropy, which is due to their unique V-shaped configurations. Interestingly, the incorporation of ferrocenyl moieties causes remarkable enhancements in the NLO response properties of designed compounds. For instance, the ferrocenyl containing compounds IA3 [2,4-diido, 6,9-di-(1-ethynyl-4-methylbenzene ferrocenyl) decaborane and IA4 [2,4-diido, 6,9-di-(1-methyl-4-((4-(prop-1-yn-1-yl)phenyl)ethynyl)benzene ferrocenyl) decaborane are found to possess notably larger amplitudes of their first hyperpolarizabilities mounting to 34.95 × 103 and 331.50 × 103 a.u., respectively. The additional substitutions of diiodo groups at 2, 4 positions of decaborane basket not only improves the NLO response but also causes further stability as indicated by vertical ionization potentials (VIPs) of all the systems in group-A. Furthermore, a structure-NLO property relation is established using TD-DFT calculations along with frontier molecular orbital (FMOs) diagrams as well as total and partial density of states (TDOS and PDOS). It is expected from the results of the present investigation that these triple-hybrid compounds can be potential candidates for NLO applications possessing additional advantages of their 2-D NLO characters and better thermal stabilities.