Synthesis, Structure And Spectroscopic Properties Of Tetrazolate-Complexes Based On In Situ Formation Of Tetrazolate Ligand

In situ hydro(solvo)thermal reaction is a promising method for synthezing new coordinationcomplexes, in which the relatively high temperature and pressure may promote unusual in situorganic ligand reactions not feasible in conventional conditions. This work mainly paid attentionon in situ hydro(solvo)thermal novel tetrazolate-complexes generation and photoluminescenceproperties. The thesis is divided into four chapters.In the first chapter, the research background is concisely introduced with the emphasis onthe current survey of metal-organic complexes of crystal engineering; and the factors inmodifying the metal-organic complexes network geometry are summarized. The coordinationchemistry of in situ generation tetrazolate complexes under hydro(solvo)thermal conditions arebriefly reviewed. In addition, the significancy and the progress of this work also have beenoutlined.The second chapter focuses on the systematic investigation of the influence of metal ionsand supramolecular interactions on the self-assembly of in situ generated tetrazolate coordinationarchitectures. A series of new metal-organic complexes, [Zn(pzta)₂(H₂O)₂] (1), [Cu(pzta)₂](H₂O)₃(2), [Cd(pzta)₂]_n (3), [Ag(pzta)]_n(4), and [Cd₂(pzta)(OH)(SO₄)]_n (5) [pzta=pyrazinyl tetrazolate]have been achieved by in situ hydrothermal synthesis from pyrazinecarbonitrile and sodiumazide with different metal ions. Complexes 1 and 2 have similar mononuclear structures bearingdistinct intermolecular hydrogen-bond interactions to form two different 3D supramolecularnetworks based on 4⁴-subnets. Complex 3 features a one-dimensional crossed-shape chainstructure. Complex 4 is a coordination polymer comprised of mildly undulated 2D layers with a(4.8²) topological network. Complex 5 is three-dimensional open framework constructed bypentanuclear cadmium clusters, in which Cd(â…¡) atoms are connected byμ5-SO₄ units andhydroxyl. The structure is reinforced by pzta ligands to give a 3D inorganic cationic diamondoidnetwork. The configurations of the series of complexes 1-5 span from mononuclear (1, 2), one-(3) and two- (4) to three- (5) dimensions, which indicates that metal ions play an essential role inthe framework formation of the in situ generated tetrazolate complexes. Furthermore, complexes1, 3 and 5 exhibit strong blue photoluminescence in a similar energy region.In chapter 3, the copper(I)-tetrazolate {[Cu₃(μ₃-Mtta)₄]Na}_n (6) is obtained bysolvo(hydro)thermal in situ reactions. Complex 6 displays a 3D 4-connected Pts net whichpossess 1D channel. Base on the dinuclear copper unit of complex 6, three copper(I)-tetrazolatecomplexes, {[Cu₂(μ₃-Mtta)₂(CN)][Na(CH₃CN)]}_n (7) and {[Cu₄(μ₃-Mtta)₂(CN)₃](H₃O)}_n (8) (Mtta=5-methyl tetrazolate) were obtained using the azole-SBU strategy; 7 is anon-interpenetrated 3D cubic pcu net containing guest molecules in the porous channels, while 8exhibits a 3D 1vt net with rare four-fold interpenetrated structure. Hence, two differenttopological types of Cu(â… )-tetrazolate coordination polymers are successfully achieved using theazole-SBU "joints" and CN- "struts" strategy. The formation of distinct networks are influencedby the variable coordination number of Cu(â… ) centers and the amount of coordinating CN-ligands. The common Pts net (6), pcu net (7), and the rare four-interpenetrating 1vt net (8)illustrate the both types of "simple, high-symmetry" structures.In chapter 4, further studies of the influence of halogen I^- on structures ofcopper(â… )-tetrazolate are carried out. Two different substituted nitrile derivatives were selected toconstruct extended frameworks based on Cu_nI_n clusters by the catalysis of CuI. Threecopper(â… )-tetrazolate complexes which contain Cu_nI_n clusters were obtained. ComplexCu₅(μ₄-Mtta)₃(μ₆-I)(μ₂-I)}_n (9) displays a 2D structure possessing of ten-nuclear Cu clusters.Complex {Cu₅(μ₅-Mtta)₃(CN)μ₄-I}_n (10) is a 3D framework constructed by 16-member loops.Complex {[Cu₂(μ₅-Btta)(μ₃-I)}_n (11) exhibits a 3D self-penetrating network. All of threecomplexes possess the neutral dimers Cu₂I₂ forming three kinds of (Cu_nI_n) cluster cations, whichis bridged by tetrazolate to generate various architectures.