Syntheses, structural, theoretical, and nonlinear optical studies of non-interpenetrating three-dimensional nest-shaped-cluster [MoOS ₃Cu₃]-based coordination polymers

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.