EXPLOITATION OF PROTON AND ELECTRON COOPERATIVE MOLECULAR SYSTEMS BUILT UP BY HYDROGEN BONDED METAL

利用过渡金属离子的氧化还原过程实现质子-电子协同体系，需要通过强氢键相互作用形成具有混合价络合物的新分子体系。我们已经证明了由金属离子和2,2 -双咪唑单阴离子（Hbim^<-1>）组成的分子构建体系不仅可以通过配体之间互补的NH-N氢键自组织形成有序的超结构。金属离子氧化数的变化也会极大地改变配体中两个NH质子的pKa_1和pKa_2值。本文提出了一种新的分子体系[Re^<III>Cl^2(PPh_3)(Hbim)]_2配合物(1)，具有氢键二聚体结构。有趣的是，络合物1上的循环伏安图显示了Re^<II>、Re^<II>、Re^<II>、Re^<III>、Re^<III>、Re^<III>、Re^<III>、Re^<IV>、Re^<IV>、Re^<IV>上的可逆和准可逆氧化还原电位。通过测量介电常数，配合物1将显示出与两个Re离子混合价态的电子转移和两个hhm ^<-1>配体之间互补的分子间氢键互变异构化的质子转移有关的双功能。

Realization on a proton and an electron cooperative system using redox process of transition metal ions has required making up of a new molecular system with a mixed valence complex through a strong hydrogen-bonding interaction. We have already demonstrated that molecular building systems with a metal ion and 2, 2-bimidazolate monoanion (Hbim^<-1>) can be formed not only the ordered super-structures by self-organization using complementary NH-N hydrogen bonds between the ligands. But also variation on oxidation number of a metal ion can greatly change the pKa_1 and the pKa_2 values of two NH protons in the ligand. Here it is presented that a new molecular system, [Re^<III>Cl^2(PPh_3)(Hbim)]_2 complex (1), with a hydrogen-bonded dimmer formation was prepared. Interestingly, the cyclic voltammogram on the complex 1 indicated reversible and quasi-reversible redox potentials on Re^<II>Re^<II>【tautomer】Re^<II>Re^<III>【tautomer】 Re^<III>Re^<III>【tautomer】Re^<III>Re^<IV>【tautomer】Re^<IV>Re^<IV>. Complex 1 will show the bi-functionalities on relation to an electron transfer in the mixed valence state of two Re ions and a proton transfer for tautomerization of complementary intermolecular hydrogen-bonding between two Hbim^<-1> ligands, by measuring on dielectric constant.