Controlled Synthesis And Properties Of 1-D Molecular Chain From Tetraazadiphenol Macrocyclic Complex As Support

In this paper, homodinuclear metal complexes of tetra-nitrogen macrocyclic ligands containing two phenoxide groups were obtained, which were the [2+2] condensation products of 1, 3-diaminopropane with 2, 6-diformyl-4-R-phenol(where R=Me, Cl, and F) in the presence of metal ions. Then A series of novel one-dimensional chain-like coordination polymers have been designed and synthesized with supermolecular self-assembly between the macrocyclic ligands and 1, 4-Bis(triazol-1-ylmethyl)benzene.These coordination polymers were characterized by infrared spectroscopy(IR), cyclic voltammetry(CV), UV-visible absorptions-pectrum(UV-Vis), diffuse reflectance spectroscopy(DRS). The corresponding band gap Eg was calculated between the highest occupied molecular orbital HOMO and the lowest unoccupied molecular orbital LUMO. The detailed coordination polymers are displayed as follows(the structures of relative ligands are given in Figure I): [Cu2L2(1,4-Bix)]ClO4 1;[Zn2L1(1,4-Bix)2](ClO4)2·8H2O 2; [Zn2L3(1,4-Bix)]ClO4·CH3 CN 3; [Mn4L2(1,4-Bix)3]Cl2 · 8ClO4· 6H2O4; [Mn2L3(1,4-Bix)2](ClO4)2·5H2O 5. The main research work was listed as following:Enough 2, 6-diformyl-4-R-phenol was synthesized as intermediates. Five one-dimensional chain coordination polymers 1-5 were obtained by the [2+2] condensation products of 2, 6-diformyl-4-R-phenol with 1, 3-diaminopropane in the presence of 1,4-Bis(triazol-1-ylmethyl) benzene and M(ClO4)2·6H2O. X-ray structure determination showed that the chain structure is formed from the macrocyclic structure coordinating two metal ions linked by 1, 4-Bis(triazol-1-ylmethyl)benzene molecules. The experimental results show that coordination polymers 1,2,3,5 exhibited an infinite one-dimensional chain structure while coordination polymer 4 exhibited tetranuclear manganese complex dimer. In coordination polymer 4, Mn2+ ions have the different coordination environment which can be regarded as tetragonal pyramid, octahedral respectively. In addition, Robson-type Schiff base macrocyclic complex exhibits saddle-like structure. In coordination polymer 1, Cu2+ ions have the same coordination environment which can be described as tetragonal pyramid. Similarly, Zn2+ ions in coordination polymer 3 also presented the same coordination polyhedron which can be regarded as tetragonal pyramid. In coordination polymer 2, Zn2+ ions have the same coordination polyhedron, namely octahedral. The coordination environment of Mn2+ ions in coordination polymer 5 is similar to that of 2. Cyclic voltammetry(CV) studies show that coordination polymers 1, 2 and 5 behave two reduction peaks and one oxidation peak. Among them, one pair of redox peak is quasi-reversible in the range of potential- 1.4 V~+1.4 V. Coordination polymer 3 behaves two pairs of redox peaks which are quasi-reversible in the range of potential- 1.4 V~+1.4 V. Coordination polymer 4 behaves one reduction peak and two oxidation peaks. Similarly, one pair of redox peaks(Mn(II)Mn(II) /Mn(Ⅲ) Mn(II)) at Half-wave potential-0.788 V are quasi-reversible in the range of potential-1.4 V ~ +1.4 V. UV-visible absorption spectrum(UV-Vis) studies show that coordination polymers 1, 2, 4 and 5 appear two absorption peaks in the ultraviolet region, in contrast, coordination polymer 3 in the ultraviolet region appears more absorption peaks in the ultraviolet region. Diffuse reflectance spectroscopy(DRS) studies show coordination polymers 1-5 exhibit absorption peaks in the UV-visible region. Finally, band gap Eg of the coordination polymers are calculated respectively.Coordination polymers 6-8 from research group were obtained by reaction of 2, 6-diformyl-4-R-phenol with 1, 3-diaminopropane in the presence of 4, 4-bipyridine and M(ClO4)2·6H2O. X-ray structure determination showed that coordination polymers 6-8 have an infinite 1-D molecular ladder motif composed of macrocyclic dinuclear copper complex with 4,4′-bipyridine molecules. The coordination polyhedron of each copper(II) ion in coordination polymers 6, 7 have the same coordination environment which can be described as octahedral and the coordination polyhedron of each zinc(II) ion in coordination polymer 8 also can be described as octahedral. So the entire macrocyclic molecules twisted slightly. Cyclic voltammetry(CV) studies show coordination polymers 6, 7 and 8 behave two reduction peaks and one oxidation peak. Among them, one pair of redox peak is quasi-reversible in the range of potential-1.4 V~+1.4 V. UV-visible absorption spectrum(UV-Vis) studies show that coordination polymers 6,7 and 8 appear two absorption peaks in the ultraviolet region, and all the absorption peaks are small at 400 nm. In addition, diffuse reflectance spectroscopy(DRS) studies show that coordination polymers 6,7 and 8 exist absorption phenomenon in the UV-visible region. Lastly, band gap Eg of the coordination polymers are calculated respectively.