Metal Complexes Of Polybenzimidazole Ligand: Their Synthesis And Inductive Roles In DNA Condensation

Two polybenzimidazole ligands:N,N,N',N'-tetrakis(2'-benzimidazolylmethyl)-1,4-di -ethylene amino glycol ether(EGTB) andl,1,4, 7,7-pentakis(1H-benzimidazol-2-ylmethyl) -1,4,7-triazaheptane(DTPB) have been synthesised. We also synthesise five metal complexes with EGTB or DTPB.All of the compounds[Cu₂(EGTB)(Ac)₂](Ac)₂·7H₂O(1),[Cu₂(DTPB)Cl₂]Cl₂·5H₂O·2CH₃OH(2),[Co₂(DTPB)Cl₃]Cl(3),[Mn(DTPB)Ac]Ac·8H₂O (4),[Mn₂(DTPB)(NO₃)₂(H₂O)₂] [Mn₂(DTPB)(NO₃)₂·H₂O·CH₃OH](NO₃)₄·4CH₃OH·H₂O (5) have been characterized by X-ray diffraction, the structure characters are as follows:1 is a dinuclear complex .Each of the center Cu(â…¡) is bonded to three N atoms,one O atom from EGTB and two O atoms from Ac^- ,to form a octahedron geometry.2 is a dinuclear complex .One of the center Cu(â…¡) is bonded to two benzimidazolyl nitrogens, two amine nitrogens from DTPB and two Cl^- ,to form a tetragonal pyramid;the other is bonded to three benzimidazolyl nitrogens, one amine nitrogens from DTPB and a Cl^- ,to form a trigonal bipyramid.3 is a dinuclear complex .One of the center Co(â…¡) is bonded to three benzimidazolyl nitrogens, two amine nitrogens from DTPB and a Cl^- ,to form a octahedron geometry;the other is bonded to two benzimidazolyl nitrogens, one amine nitrogens from DTPB and two Cl^- ,to form a trigonal bipyramid.4 is a mononuclear complex .The center Mn(â…¡) is bonded to three N atoms,two amine nitrogens from DTPB and one O atom from Ac^-,to form a octahedron geometry.5 is a dinuclear complex. One of the center Mn(â…¡) is bonded to three benzimidazolyl nitrogens, two amine nitrogens from DTPB and two O atoms of NO₃^- ,to form a pentagonal bipyramid;the other is bonded to two benzimidazolyl nitrogens, one amine nitrogens from DTPB,one O atom and two O atoms of water molecule ,to form a octahedron geometry.Interactions between compound 4,5 and DNA have been investigated by ultraviolet -visible spectra and fluorescence spectra.The results manifest the two compounds can bond DNA.The inductive roles of the two complexes in DNA condensation have been studied by gelose gel electrophoresis,RALS and DLS.The results indicate the compounds can induce DNA condensation in neutral condition and different DNA condensates have been detected by TEM.