Syntheses, Structures And Properties Of Functional Coordination Complexes And Molecular Architectures Based On N-and O-containing Ligands

Recently, design and syntheses of metal-organic frameworks (MOFs) based on carboxylic ligands through metal-ligand coordination and intermolecular superamolecular interactions have been shown much interest due to their particular topologies and some potential applications such as catalysis, adsorption, magnetism, photochemistry and NLO materials. In this thesis, N- and O-containing ligands are designed and synthesized as multifunctional ligands. 17 new coordination polymers have been prepared and the photoluminescent properties have been characterized.This dissertation covers the following three parts:1.Three complexes are hydrothermal synthesized from 6-hydroxynicotinic acid (H₂L¹), phen and 4,4'-bipy, namely [Cu₂(HL¹)₄(bipy)₂]_n·5nH₂O (1), [Cd(HL¹)(NO₃)(phen)]_n (2) and [Cd₂L₂¹(phen)₂]_n·0.25nH₂O (3). Complex 1 is 1D chain structure and these chains are further joined together to be a 3D superamolecular architecture through hydrogen bond. 2 and 3 are 2D layer structure.2.After Design and synthesis of a new ligand, N- acetic-6-oxidonicotinic acid(H₂L²), based on H₂L¹ 8 new complexes are obtained, namely [Cu(HL²)₂(H₂O)]_n·2nH₂O (4), [Zn(HL²)₂(H₂O)]_n·2nH₂O (5), [Mn(HL²)₂(H₂O)]_n·2nH₂O (6), [Cd(HL²)₂(H₂O)]_n·2nH₂O (7), [ZnL²(phen)(H₂O)]_n·nH₂O (8), [CdL²(H₂O₎2]_n·3nH₂O (9), [Zn₂L²(OH)₂(H₂O)]_n(10), [ZnL²(H₂O)]_n (11). Complex 4, 5, 6 and 7 are allomerisms with 1D chain structure. 8 is a 3D superamolecular architecture constructed from 1D chain while 9 and 10 are 2D layers. Complex 11 is the only 3D structure because all the coordination sites take participate in coordination.3. we have successfully designed a new multicarboxylate ligand: 3,5-bis-carboxymethoxy-benzoic acid (H₃L³) which possesses rigid and flexible carboxyl groups and hydrothermal synthesizes 6 unique complexes,namely [Zn₂L³(OH)]_n·nH₂O (12),[Zn₄L₂³(OH)₂(4,4'-bipy)₂]_n·nH₂O·0.5nEtOH(13), [Cd₃L₂³(H₂O)₆]_n·6nH₂O (14), [Cd₄L₂³(OH)₂(phen)₄]_n·nH₂O (15),[Mn₃L₂³(4,4'-bipy)₂(H₂O)₄]_n·nH₂O (16) [Cu₃L₂³(phen)₂(H₂O)₂]_n (17). 12 features an unusual 5-connected 4⁶.6⁴ uninodal net with both the dinuclear Zn unit and the L³ ligand being the square pyramidal nodes. 13 presents an interesting 3D (3,8)-connected network constructed from pillared undulate layers. 14 and 15 are monolayer structures. 16 is a unique 1D chain structure with double M face-to-face construction while 17 is a 2D net with trinuclear clusters. All complexes have been determined by single-crystal X-ray diffraction, IR, thermal stabilities analyses and photoluminescence. And some of complexes are also characterized by preliminary NLO property, UV-vis property and theoretical analyses on photoluminescence. After investigation, it is found that strong basic condition leads to high dimensional structure; anions have great efforts while auxiliary ligands possibly act as structure-directing reagents; The photoluminescence properties of the metal-organic complexes depend on the nature of the organic ligand as well as the metal ions.