Covalent Organic Functionalization Of Transition-metal-substituted Tungsten-oxo Clusters Under Hydrothermal Conditions

Directed by the idea of lacunary-directed synthesis first summarized by our groupunder the practice and experience of the exploration on the metal-oxo clusters that thelacunary sites of various polyoxometalate (POM) precursors could act as the structuredirecting agents, which induce different metal ions to form novel metal-oxo clusters, theresearch work of this dissertation aims to introduce various kinds of tungsten-oxo lacunaryprecursors and the second type of transition-metal ions into the hydrothermal reactionsystem to obtain novel high-nuclear-or super high-nuclear-metal-substituted tungstate-oxoclusters (TMSTs) and aggregates. Based on lacunary directed synthesis mentioned aboveand hard work and introducing chelate organic ligands to act as structure-stabilizing agents,a series of unprecedented covalent organic functionalized TMSTs, including isolatedmonomers, dimers, tetramers and polymers were successfully made and could be classifiedas four series with a total of41compounds, which were characterized by elementalanalyses, FT-IR, ultraviolet-visible diffused reflection and thermogravimetric analyses,powder X-ray diffractions, single-crystal X-ray diffractions and relevant properties. Thesuccessful isolation of these compounds not only provides a novel route for extending thesynthetic idea of chemistry of TMSTs, but also enriches the structural type of chemistry ofTMSTs and developing the inorganic-organic hybrid materials.Series1: By introducing sundry chelate organoamines, fatty acids and tripodal alcoholligands (Tris), fourteen discrete symmetric/asymmetric covalent organic functionalized{Ni6XW9}(X=P, SiIV, GeIV, AsV) clusters have been synthesized hydrothermally,including four isolated {Ni6PW9} species covalent organic functionalized by simple chelateorganoamines (compounds3-1to3-4); two products with in-situ cyclocondensation oforganoamine reation, one of them is isolated {Ni6PW9} cluster (compound3-5), the other isan extended structure with1D chain (compound3-6); four Tris ligands asymmetriccovalent organic functionalized {Ni6XW9} clusters (compounds3-7to3-10), whencompounds3-9crystallized as chiral space group, compounds3-10was structurallycharacterized as1D chain-like cluster; two isostructural isolated chelate organoamineasymmetric covalent organic functionalized {Ni6XIVW9}(X=Si and Ge) clusters, (compounds3-11and3-12); two isolated chelate organoamine symmetric/asymmetriccovalent organic functionalized {Ni6AsW9} species (compounds3-13and3-14). All ofthem have coupled enantiomers in their structures because of the asymmetric covalentorganic fuctionalization {Ni6XW9} species of except3-2,3-3,3-9and3-13.Series2: Eighteen amino acid asymmetric functionalized {Ni6PW9} clusters have beenmade under hydrothermal conditions after a systematic investigation for effects on chelateamines, Tris ligands, amino acids, buffers and their concentrations ionic strength, etc.,including four isolated achiral Damp asymmetric functionalized {Ni6PW9} species(compounds4-1to4-4); thirteen chiral L-Pro or D-Pro (There are conversions that L-Proand D-Pro convers to each other freely through the in-situ hydrothermal reaction incompounds4-5to4-16) asymmetric functionalized {Ni6PW9} species, isolatedmonomeric clusters (compounds4-5,4-6,4-8,4-10and4-15to4-18), three isolatedtetramers (compounds4-11to4-13) and three1D chain-like clusters (compounds4-7,4-9and4-14). Compound4-17and4-18are confirmed as single chiral structures confirmed byFlack factor.Series3: By introducing sundry chelate organoamines, two single and three mixedcovalent organoamine functionalized sandwiched CuII-substituted TMSTs have beenobtained hydrothermally, including one1D chain-like semi-di-CuIIcluster (compound5-1),one en/enMe mixed organoamine functionalized sandwiched tetra-CuII-substituted TMST(compound5-2), one en/dien mixed organoamine functionalized sandwichedhexa-CuII-substituted TMST (compound5-3), one en/enMe mixed organoaminefunctionalized sandwiched hexa-CuII-substituted TMST (compound5-4) and onesandwiched octa-CuII-substituted TMST (compound5-5).Series4: By introducing3d-3d’ mixed transition-metal to various kinds of lacunaryprecursors of tungsten-oxo clusters in hydrothermal system, four novel3d-3d’ mixedtransition-metal co-functionalized TMSTs have been synthesized, including oneCuII-FeII-FeIIIco-functionalized2D extended tetra-FeII/FeIII-substituted kegging-type TMST(6-1), one CuII-FeIIIco-functionalized isolated di-semi-FeIII-substituted Dawson-type TMST(6-2), one unprecedented CuII-VIV-SbIIIco-functionalized1D chain-liketri-VOII-tri-SbIII-substituted kegging-type TMST (6-3) and one unprecedented B-ZnII-VIV-SbIII-WVIpenta-metal-non-metal system with four kind of clusters, V-O, W-O,B-O and tri-VOII-tri-SbIIIclusters (6-4).