Study On The Synthesis, Structure And Properties Of New Phosphonate-based Tetrazolium Complexes

In this paper we designed and synthesized three new ligands with both phosphonate group and tetrazole group:diethyl 4-(2H-1,2,3,4-tetrazol-5-yl)benzylphosphonate[(R1)2L1],methyl hydrogen 4-(2H-1,2,3,4-tetrazol-5-yl)benzylphosphonate R2L2 and diethyl 4-(2-ethyl-2H-1,2,3,4-tetrazol-5-yl)benzylphosphonate R1L3,(R1=C2H5,R2=CH3).Based on these three ligands,six different complexes are obtained with transition metals:[Zn(R1L1)]n(1),[Zn(L2)]·2H2O(2),[Co(R,L1)(H2O)]·H2O(3),[Cd(R1L1)(H2O)]·H2O·C2H5OH(4),[Cd(L1)(H2O)]·H2O(5),[Zn(L3)(H2O)]n(6).Complexes 1,3,4,5 are constructed respectively by the reactions of ligand(R1)2L1 with different transition metals under hydrothermal conditions,2 and 6 are obtained by Zn(NO3)2·6H2O reacting with the ligand R2L2 and(R1)2L3 respectively under hydrothermal conditions.Both complexes 1 and 2 show 3D channel structures with same coordination mode constructed from same metal zinc and different ligands.Whereas,different porous properties are found to be formed in 1 and 2.The channels in 1 are lipophilic and those in 2 are hydrophilic.1 and 2 also have novel topology structures without reported previously.Complexs 3 and 4 are isomorphic with 2D network structures,obtained under same hydrothermal conditions.Complex 4 and 5,synthesized under different pH values,have different coordination modes and different structures.5 shows 1D chain compared with the 2D network of 4.Complex 6 constructed by ligand R1L3 with a 2D layer structure are formed in the same hydrothermal condition as 1.Only O from the phosphonate group in 6 is coordinated,however,both 0 from the phosphonate group and N from the tetrazole group are coordinated in 1.It is probably because an ethyl group is transferred to tetrazole ring from phosphonate group compared L3 in 6 with R1L1 in 1.All six complexes are characterized by elemental analysis,IR spectra,TG-DSC and XRD power diffraction.In addition,the three ligands and complexes 1,2,5,6 are also analyzed by fluorescence spectra,all of which exhibit good fluorescence properties.Magnetism property is also conducted for complex 3,the atoms of Co in which show changes ferromagnetism.