| The nitrogen heterocyclic ligands have strong coordination ability with the transition metal ion.Cuprous complex not only have various structures but also have important applications in photoluminescence,photocatalysis,photodegradation,biopharmaceuticals,adsorption and heterogeneous catalysis.In this thesis,one mononuclear cuprous complex,one binuclear cuprous cluster compound and seven cuprous coordination polymers bearing 2-?2'-pyridyl?benzoxazole?2-PBO?,2-?4'-pyridyl?benzoxazole?4-PBO?,2,2'-?1,4-butyl?bis-1,3-benzoxazole?BBO?and a sulfur ligand?SPPh3?,have been synthesized by natural volatilization,interfacial diffusion,interfacial reaction and solvothermal.The complexes were characterized by elemental analysis,UV-visible,infrared and X-ray single crystal diffraction to determine the structure and composition of the complexes.The electrochemical properties,solid state fluorescence properties and biological activities of the complexes were investigated.The specific research contents are as follows:1.Reaction of 2-?2'-pyridyl?benzoxazole?2-PBO?,2-?4'-pyridyl?benzoxazole?4-PBO?and 2,2-?1,4-butanediyl?bis-1,3-benzoxazole?BBO?ligands with CuX?X=I,Br,SCN?afforded a binuclear copper?I?complex[Cu2?2-PBO?2??2-I?2]·MeCN?1?and three copper?I?coordination polymers[Cu?4-PBO???3-I?]n?2?,[Cu?4-PBO???3-SCN?]n?3?,[Cu?BBO???2-Br?]n?4?.The structural analysis revealed that the all cuprous ions are four-coordinated and the geometric structure around the central cuprous atom possessing slightly distorted tetrahedral geometry in complexes 1-4??4=0.872-0.942?.Halogen or pseudohalide ions can not only act as counter anions,but also as ligands participation in coordination when the cuprous ion coordination sites are not saturated.Due to the different coordination modes of the benzoxazole ligands,in order to satisfy the tetra-coordination of cuprous ions,halogen or pseudohalide ions adopt?2 and/or?3-bridging modes to synergistically complete coordination.In complex 1,the Cu???Cu distance is 2.57?,which is much smaller than the van der Waals radius of 2.80?,indicating a strong metal-metal bond interaction.There are two different Cu???Cu distances,2.718 and 2.848?,respectively in complex 2,which are close to the van der waals radii,indicating the presence of weak metal-metal bond interactions.According to the soft and hard acid-base theory,this may be due to the fact that the cuprous ion matches the orbital of the iodide ion resulting in a metal-metal bond interaction.Photoluminescence investigation show that complexes 1,3 and4 have two emission peaks,the high energy band peak is attributed to MLCT[d10?Cu???*]and XMCT,the low energy band peak is caused by the 3CC emission.However complex 2only had one emission peak,which may be attributed to MLCT[d10?Cu???*]and XMCT.This may be due to the presence of?2-X?X=I,Br,S?in these complexes,while the complex 2contains only?3-I,resulting in a difference in the fluorescent properties of the complexes 1-4.The electrochemical properties of complexes 1-4 by cyclic voltammetry show that:complexes1-4 have a pair of irreversible CuI/CuII redox couples.The free radical scavenging activity of the complexes showed that the complexes 1 and 4 have good antioxidant activity against superoxide and hydroxy radicals in which the complex 1 has the highest activity,and the IC50value was?1.24±0.01?×10-7 M.2.Four cuprous coordination polymers and one mononuclear cuprous complex,namely:{[Cu?BBO?3]·PF6}n?5?,{[Cu?BBO?2?CH3CN?2]·BF4}n?6?,{[Cu?BBO?2?SPPh3?]·BF4}n?7?,{[Cu?BBO??SPPh3?]ClO4}n?8?and one mononuclear cuprous complex{[Cu?SPPh3?3]PF6}2?9?bearing a bisbenzoxazole ligand,2,2'-?1,4-butanediyl?bis-1,3-benzoxazole?BBO?and auxiliary ligand triphenylphosphine?SPPh3?have been synthesized,and structurally characterized by elemental analyses,IR,UV-Vis and single-crystal X-ray diffraction.The structural analysis revealed that the structures of coordination polymers 5,7,8 and complex 9are both three-coordinated and show distorted trigonal planar geometry in which the coordination polymers 7 and 8 are one-dimensional helical chain coordination polymers,and the coordination polymer 5 is a two-dimensional planar coordination polymer.The crystal structure of complex 9 shows two crystallographically independent but chemically identical[Cu?SPPh3?3]PF6 units.The coordination polymer 6 is a tetracoordinated space configuration of a twisted tetrahedron??4=0.945?in which two BBO link Cu?I?ions into a one-dimensional zigzag chain in coordination polymer 6,while acetonitrile as an ancillary ligand distributed on both sides of the one-dimensional chain.Luminescence properties investigation show that compared with the ligands,6-9 only had one emission peak in which were red-shifted by 58,89,47 and 70 nm,respectively,which may be attributed to[MLCT(d10?Cu???*].The two emission peaks appearing in 5 are caused by?*-?transition?381 nm?and n-?*transition?401nm?.This may be due to the fact that in the 6,7 and 8,in addition to the coordination of the nitrogen heterocyclic ligand,the ancillary ligands also participate in the coordination,increasing the steric hindrance,thereby reducing the energy loss.The above results indicate that the coordination of the ancillary ligands can regulate the structure and fluorescent properties of the cuprous complex.The cyclic voltammogram of 5-9 represent a pair of irreversible CuI/CuII redox couples.The bioactivity experiments screened that complexes 7and 8 had excellent anti-hydroxyl radical activity,while complexes 6-9 exhibited good superoxide radical scavenging activity. |
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