Heterobimetallic Chalcogenide Cluster Polymers: Syntheses, Structures And Third-order Nonlinear Optic Properties

The dissertation focuses on the syntheses and structures of polymericMo(W)/S/Cu(Ag) clusters, fourteen new Mo(W)/S/Cu(Ag) polymers being prepared andstructurally characterized, of which two are 0-D, eight are 1-D, and four are 3-Dpolymers. Besides one new monomer of Mo/S/Ag cluster was also synthesized andstructurally characterized. The third-order nonlinear optic (NLO) properties of somesynthesized compounds were investigated.1. The reactions of [MO_nS_4-n]^2- (M=Mo, W; n=0,1) with CUES in the presence of[Me₄N]⁺ or [n-Bu₄N]⁺ as structure-inducer resulted in two 0-D polymeric clusters, withtrinuclear linear and novel tridecanuclear double-ring structure, respectively. The latterstructural pattern has not been observed in literatures.2. The reactions of [NH₄]₂[MS₄] with Ag⁺ induced by several different templatesled to the formation of seven 1-D Mo(W)/S/Ag polymers, of which three configurationswere found, namely linear chain, zigzag chain with '1:2' steps, and zigzag chain with'2:2' steps. The last two configurations have not been reported thus far.3. By comparing the reactive conditions and crystal structures among some 1-DMo(W)/S/Ag clusters and known analogs, it has been pointed out that the valences andradii of cationic complexes, the orientation of ligands in cationic complexes, crystallizedsolvents, and coexisting anions can all exert influences on the configurations ofpolymeric chains. These influences were analyzed in some depth. The inclusion ofcoexisting anions and its impact on polymeric configuration have not been observed inthis system before.4. The synthesis and crystal structure of a 1-D W/S/Cu cluster bridged by4,4'-bipyridyl were studied and the correlation between the intermediate compound intwo-step reaction and the dimensionality of resulting products was also analyzed.5. The structures of some known Mo(W)/S/Cu(Ag) polymers were analyzed from atopological connection view and augmenting the connectivity of net-nodes was pointedout as an important approach to 3-D structures. The effects of halogens andcomplementary cations on the dimensionality of resulting products were also discussed.Based on these discussion, two reaction systems of [NH₄]₂[MOS₃]-CuCN-[Me₄N]NO₃and [NH₄]₂[MOS₃]-CuCN-4,4'-bipyridyl were studied to give four 3-D polymericclusters with [MOS₃] moieties, no such [MOS₃]^2- derivatives with 3-D structures beingreported to date. Two of the four 3-D clusters were found to possess novel ACS topologyin their anionic skeletons, and furthermore, a special two-folded inclusion is observed in these two clusters, which, to our knowledge, has not been reported in the domains ofpolymeric clusters and coordination polymers. Another two clusters assume a pillared3-D structure, with diamond topology.6. The third-order NLO properties of some synthesized clusters were investigated.Among them two neutral cubane-like clusters with terminal oxygen exhibit notablethird-order NLO properties as against no observable NLO effects found for reportedanalogs with terminal sulfur. Three 1-D Mo(W)/S/Ag polymers also show strongthird-order NLO properties, two of them having a higher secondary hyperpolarisabilityabout ten times larger than that of the reported 1-D W/S/Ag cluster. Of the foursynthesized 3-D clusters, two were found to display moderate and strong third-orderNLO properties, respectively.