Syntheses, structural, theoretical, and nonlinear optical studies of non-interpenetrating three-dimensional nest-shaped-cluster [MoOS 3 Cu 3 ]-based coordination polymers

Abstract

An efficient route to construct three-dimensional (3-D) M/S/Cu nest-cluster-based coordination polymers has been developed. By this method, cyanide bridges have been successfully introduced to build three new non-interpenetrating 3-D nest-shaped-cluster [MoOS3Cu 3]-based coordination polymers, 3∞{[(NO3)⊂(Me4N)3] ⊂[MoOS3Cu3(CN)3]} (1) and 3∞{[(NH4)·2DMF]⊂[Mo2O 2S6Cu6(CN)3(L)4]} (L 1 = bipy = 4,4′-bipyridine, 2; L2 = bpee = 1,2-bis(4-pyridyl)ethene, 3). The structures of 1-3 have been established by elemental analysis, IR, UV-vis, and single-crystal X-ray crystallographic studies. 1 is the first non-interpenetrating 3-D 6-connected M/S/Cu coordination polymer and possesses an unprecedented dual-inclusive structure, rare "ACS" topology and huge free volume. 2 and 3 possess unusual non-interpenetrating 3-D pillar-layer-alternating honeycomb-like frameworks with diamondoid topologies. Nonlinear optical (NLO) properties of these clusters were investigated by Z-scan employing 5 ns pulses at 532 nm, with 1-3 showing strong third-order NLO properties. Time-dependent density functional theory (TD-DFT) studies have afforded insight into the electronic transitions and spectral characterization of these functionalized NLO molecular materials.