Synthesis, Crystal Structure And Properties Of Transition Metal Schiff Base Complexes

On the base of 3-carboxylsalicylaldehyde, a series of its Schiff bases were synthesized with 1,2-diaminopropane,1R,2R-diaminocyclohexane,thiosemicarbazide, 2-aminobenzenthiol.With these Schiff bases as ligands,a series of transition metal complexes were obtained and characterized.(1) The complex Cu2MES·2H2O [H4MES = N,N'-bis(3-carboxylsalicylidene)-1,2- diaminopropane] was synthesized in methanol at room temperature. The structure was characterized by elemental analysis, IR, UV-Vis, thermal analysis and single crystal X-ray diffraction. It crystallizes in triclinic system, space group P-1,with a = 7.8013(10)?, b = 11.0412(14)?, c = 11.5974(15)?,α= 80.067(2)°,β= 74.129(2)°,γ= 80.627(2)°, Z = 2, R1 = 0.0495, wR2 = 0.1269. The crystal is constructed with binuclear units, in which the two copper atoms are bridged by two phenolate oxygen atoms. Copper atom 1 is coordinated by two nitrogen atoms, two phenolate oxygen atoms in a planar geometry, copper atom 2 is coordinated by two phenolate oxygen atoms and two carboxylate oxygen atoms in the same plane.(2) Complexes Ni(HCSP)2·H2O and Co(HCSP)2·1.5H2O[H2CSP = 1-(N-3-carboxyl- salicylidene)-1,2-diaminopropane] were obtained through selfassembly. The structure was characterized by IR and single crystal X-ray diffraction. Ni(HCSP)2·H2O crystallizes in monoclinic system, space group P2(1)/c, with a = 9.756(2)?, b = 14.236(3)?, c = 17.403(4)?,α=γ= 90°,β= 98.951(3)°, Z = 4, R1 = 0.0719, wR2 = 0.1844;Co(HCSP)2·1.5H2O: monoclinic crystal system, P(2)1/c space group, a = 12.728(6)?, b = 14.478(7)?, c = 15.916(7)?,α=γ= 90°,β= 108.585(6)°, Z = 2, R1 = 0.1132, wR2 = 0.3128. Both the crystals are constructed with mononuclear units, in which the metal atoms are coordinated by two phenolate oxygen atoms and four imine nitrogen atoms. 3 (3) Schiff base complexes Zn(HMODS)2 and Ni(HMODS)2, where H2MODS is the monocleating Schiff base N-3-carboxylsalicylidene(1R, 2R)-diaminocyclohexane, were synthesized and characterized. Zn(HMODS)2:orthorhombic crystal system, P2(1)2(1)2(1) space group: with a = 8.858(2)?, b = 12.610(3)?, c = 25.008(6)?, Z = 4, R1 = 0.0553, wR2 = 0.1026. Ni(HMODS)2: monoclinic crystal system, space group P2(1), with a = 9.0013(12)?, b = 12.6584(17)?, c = 12.1077(16)?,β= 93.826(2)°, Z = 2, R1 = 0.0469, wR2 = 0.0746.(4) The Schiff base complex Cu(H2DAS)·H2O was synthesized, where H4DAS is binucleating ligand N,N'-bis(3-carboxylsalicylidene)(1R,2R)-diaminocyclohexane. It belongs to triclinic crystal system, P-1 space group, a = 8.3571(10)?, b = 10.8415(13)?, c = 12.5327(15)?,α= 84.531(2),β= 70.9210(10)°,γ= 80.266(2)°, Z = 1, R1 = 0.0768, wR2 = 0.2354.(5) The 3-carboxylsalicylidene-thiosemicarbazide Schiff base(TSS)and corresponding complex Co(C9H8N3O3S)2 were gained and characterized by element analysis, IR, thermal analysis and X-ray crystallography. The crystal belongs to monoclinic crystal system, space group C2/c, a = 15.526(2)?, b = 25.659(4)? , c = 25.262(5)?,β= 93.709(3)°, Z = 16, R1 = 0.1386, wR2 = 0.3735, the cobalt atom is in an aberrance octahedron coordination site of N2O2S2.(6) The ternary complex [Cu(C8H4O4)(C12H8N2)(H2O)]·CH3OH, where C8H4O42- is 3-carboxylsalicylaldehyde dianion and C12H8N2 is o-phenanthroline, was synthesized. The crystal belongs to triclinic crystal system, P-1 space group, with a = 8.6714(11)?, b = 10.3895(13)?, c = 11.7617(14)?,α= 115.125(2),β= 95.859(2),γ= 93.589(2)°, Z = 2, R1 = 0.0464, wR2 = 0.0978. The Cu(II) ion is pentacoordinated in a tetragonal pyramid geometry, with two O atoms of 3-carboxylsalicylaldehyde dianion and two N atoms of o-phenanthroline occupying the square plane, and the water's O atom locating at the axial site.