Syntheses, Structural, Theoretical, and Nonlinear Optical Studies of Non-Interpenetrating Three-Dimensional Nest-Shaped-Cluster [MoOS₃Cu₃]-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 [MoOS3Cu3]-based coordination polymers, 3 ∞{[(NO3)⊂(Me4N)3]⊂[MoOS3Cu3(CN)3]} (1) and 3 ∞{[(NH4)·2DMF]⊂[Mo2O2S6Cu6(CN)3(L)4]} (L1 = 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.

Nonlinear optical properties, upconversion and lasing in metal–organic frameworks

“…TTA does not require the simultaneous absorption of two photons, which allows it to work at very low power excitations. 67,126,133 It is not formally an NLO process as it utilizes ordinary one-photon absorption, although the bimolecular character of the exciton interactions makes it similar to two-photon NLO processes.…”

“…17b). 67,128,134,135 The UC quantum yield (F UC , the fraction of upconverted photons per absorbed photons) can be described as the product of the quantum efficiencies of all involved photophysical processes according to the following equation:…”

Tetrazine Chromophore‐Based Metal–Organic Frameworks with Unusual Configurations: Synthetic, Structural, Theoretical, Fluorescent, and Nonlinear Optical Studies

“…Using the so‐called interdiffusion method,9d the reaction of [Et 4 N] 2 [WS 4 ] and CuCN (molar ratio 1:3) with 4,4′‐pytz afforded 1 as a T‐shaped [WS 4 Cu 3 ] + ‐containing MOF, the combination of [NH 4 ] 2 [MoS 4 ] and CuCN (molar ratio 1:4) with 4,4′‐pytz gave 2 as a pentanuclear planar open‐shaped [MoS 4 Cu 4 ] 2+ ‐containing MOF, and the assembly of [NH 4 ] 2 [WS 4 ] and Cu[N(CN) 2 ] (molar ratio 1:3) with 4,4′‐pytz afforded 3 as an unexpected 3D flywheel‐shaped [WS 4 Cu 3 ] + ‐containing MOF (Scheme ). The phase purities of the bulk products of 1 – 3 were independently confirmed by using powder X‐ray diffraction (Figure S1 in the Supporting Information).…”

“…The interdiffusion method9d employed in these studies used a solvent polarity‐tunable buffer layer to separate the polar and nonpolar solutions, one of which included the soluble M/S/Cu clusters, whereas the other contained precipitating agents, such as a counterion or a conjugated bridging ligand. When these two solutions diffused into the buffer layer, the M/S/Cu MOFs were formed and crystallized in the buffer layer.…”

Spacer length-directed construction of two-dimensional [MoS3Cu3]-based coordination polymers from a precursor cluster [PPh4][Cp∗MoS3(CuNCS)3] (Cp∗=η5-C5Me5) and 4-pyridyl-based ditopic ligands

“…Several groups in the world are interested in the construction of cluster-based coordination polymers from the preformed Mo(W)/Cu/S clusters due to their rich structural varieties and unique physicochemical properties [18][19][20][21]. Studies in this respect have not only offered tremendous potential for tailoring materials to have intriguing structural aspects , specific physical characteristics [23][24][25][26][27]29,[34][35][36][38][39][40][41][42][43][44]48,49] and chemical functionalities [30,37,44,47], but also provided great challenges in the understanding of the synergism between the cluster core and the ligand, as well as the correlation between the reactant and the product.…”