The Structures And Properties Of Coordination Complexes Built From N-Neterocycle/Carboxylate Ligands

Coordination polymers have been an active research field and especially popular with the chemical workers, arising from not only the diversification and tunability of their architectures, but also their distinctive physical properties in nonlinear optics, gas storage, magnetism and heterogeneous catalysis. At the current stage, the core tasks of the research subjects are to design appropriate building unit and apply the relevant crystal engineering strategy to fabricate the new functional crystal materials with expectedly unique structure and superior performance. Based on this, we conduct the systematic and in-depth research into the influence factors of crystalline structure, and further seek the structure-activity relationship between structures and properties. In this paper, we select a flexible bis(methylbenzimidazole) ligand(hbmb), a semirigid bis(thiazolylbenzimidazole) ligand(btbb), an asymmetric tripodal multicarboxylic ligand(H3L), an ether-linked flexible tetracarboxylic acids ligand(H4L) as the main ligands, severally, successfully acquiring 37 new complexes via hydro(solvo)thermal synthetic method. We detailedly analyze and expound their structural characteristics utilizing network topology method, and carefully examine the impact of N-donor/carboxylate linkers on the final networks. Furthermore, according to the respective features of these complexes, their fluorescent properties, solvent resistance properties, catalytic properties, magnetic properties have also been explored. This thesis includes the following seven parts:1. Eight entangled coordination complexes have been prepared by the reactions of the flexible ligand hbmb with Zn(II)/Cd(II) ions in the presence of diversiform dicarboxylate coligands. 1 and 2 exhibit 6-connected self-penetrating 3D roa frameworks. 3 and 4 display 4-fold interpenetrating 3D 66-dia frameworks. 5 and 6 reveal 2-fold interpenetrating 6-connected 3D pcu frameworks. Both 7 and 8 are 4-connected 3D frameworks built through unusual 2Dâ†'3D parallel interpenetration, of which 7 presents a(44·62)2 topology and 8 shows a 44·62 topology. A systematic structural comparison of four pairs of complexes manifests that the frameworks can be tuned by diverse dicarboxylate coligands and changeable conformations of hbmb ligand. Moreover, 1-8 exhibit excellent solvent resistance to boiling water and usual organic solvents. Their strong fluorescence emissions indicate that they may be used as underlying photoluminescent materials.2. Five 2D Zn(II)/Cd(II)-containing coordination complexes based on hbmb and different dicarboxylates have been synthesized. 9 is an undulated structure with(63)2 topology, containing left- and right-handed helical chains. 10 possesses a puckered 44·62 topology. 11 exhibits a(4,4) parallelogram network and also owns left- and right-handed helical chains. 12 and 13 display four-connected rectangular grids with 44·62 topology. 9-13 show good thermal stability and good luminescent properties.3. The synchronous use of the btbb and related carboxylate coligands to react with Cd(II) ions affords six complex architectures. 14 features a 6-connected 3D 412·63-pcu alpha-Po primitive cubic topology net. All of complexes 15, 16 and 18 contain left- and right-handed helical chains(15: a 2-fold interpenetrating 3D(412·63)-pcu architecture; 16: a(3,6)-connected net with(42·54·66·7·82)(4·62) topology; 18: a(3,4)-connected(42·6)(42·63·8)-3,4L83 topology net). 17 exhibits a(3,4)-connected(84·102)(8·102)-3,4T48 topology net. 19 possesses a(3,5)-connected(42·6)(42·67·8)-3,5L2 topology. The relatively narrow optical energy gaps of 14–19(< 2.30 e V) reflect their outstanding semiconductive nature. The photocatalytic behaviors of 14–19 attest that 16, 17 and 19 may be good photocatalysts for the photodegradation of MB. While the interpenetrating framework 15 containing helical chains could be not good for starting the decomposition reaction.4. In the presence/absence of auxiliary N-donor ligands, four complexes containing CdII clusters have been acquired by the reactions of CdII salts and H3 L. 20 based on trinuclear CdII clusters exhibits a(3,3,6)-connected 3D framework. 21 belongs to a(3,3,8,8)-connected tfz-d topology net assembled by two kinds of trinuclear CdII clusters. 22 features a(3,8)-connected tfz-d net based upon one kind of trinuclear CdII cluster. 23 presents a 3D(3,6,10)-connected framework with dinuclear and tetranuclear clusters. The study on optical energy gaps of 20–23 signifies that they are latent semiconductive materials. The photocatalytic experimental results demonstrate that the cluster complexes containing different kinds of nuclei may exert different impact on the decomposition of disparate organic dyes.5. Two high-connected trinuclear Mn(II)-clusters molecular magnetism have been fabricated by engaging a H3 L ligand to self-assemble with Mn(II). 24 is a 3-nodal(3,4,9)-connected new topology. 25 is a 4,8-c flu network topology. 24 and 25 own high thermal stability and distinguished solvent resistance in boiling water and common organic solvents. χMT-T and χM-1-T measurements make clear that both of them exhibit ferromagnetic behaviour at the low-temperature region. Their magnetization curves M(H) does not reach the clear saturation values, and no hysteresis loop was observed. By alternating-current(AC) susceptibility measurements, the frequency-dependent peaks do not appear, declaring that there is no slow relaxation behavior of the magnetization. The FC and ZFC data of 24 display the divergence over the temperature range 40-3.5 K. 25 is based on a typical –J1J1J2– sequence, featuring the ferrimagnetic chain of a(5/2, 10/2) spin topology.6. Five Co(II)/Mn(II)/Cu(II) architectures have been obtained using main ligand H4 L. 26 presents a(4,4)-connected 2D sql net with(44·62)2 topology, which are finally extended to a 3D supramolecular framework by π···π stacking interactions. 27 has a 3D(4,4)-connected new topology net with point symbol of(86)2. 28 features a(4,4)-connected 3-fold interpenetrating 3D(42·84)2-pts topology network. 29 possesses two binuclear molecules and these adjacent binuclear units are further stretched to 2D infinite packing structure through two distinct types of π···π stacking interactions. 30 is a 2D layer structure with the(8)(84·122) topology. The magnetic studies of 26 and 28 illuminate that both of them signify antiferromagnetic interactions. 29 and 30 have been justified to be practicable heterogeneous catalysts for the synthesis of 2-imidazoline and 1,4,5,6-tetrahedropyrimidine derivatives.7. By introducing a series of N-donor coligands into the Ni(II)/L4- synthesis system, seven Ni(II) coordination complexes have been prepared. 31 presents a(4,4)-connected 3-fold interpenetrating 3D bbf net with(64·82)(66) topology. 32 belongs to a(4,4,4)-connected 3-fold interpenetrating 3D bbf network with(66)2(64·82) topology. 33 possesses a(3,4)-connected 3,4L13 net with(4·62)(42·62·82) topology. 34 features a(4,4,4)-connected mog Moganite 3D network with(4·64·8)2(42·62·82) topology. 35 exhibits a(4,5)-connected 3D architecture with(4·69)(42·66·82) topology. 36 has a(4,7)-connected 3D framework with(45·5)(47·53·611) topology. 37 is a(4,4)-connected 4,4L28 net with(42·64)(4·64·8) topology. A systematic structural comparison of 31–37 signifies that their frameworks can be adjusted by variable conformations of the flexible H4 L ligand and divers N-donor ligands. The variable-temperature magnetic susceptibilities of 36 display overall weak antiferromagnetic coupling between the adjacent Ni(II) ions. 33, 35, 36 and 37 can serve as valid catalysts for the synthesis of the biphenyl.