Dinuclear Cobalt(II) Complex with <i>N</i>,<i>N</i>,<i>N</i>&prime;,<i>N</i>&prime;-Tetrakis(3,5-dimethyl-1-pyrazolyl)methyl-1,4-phenylenediamine Having a Tetrahedral Coordination Geometry

Abstract

We have engaged in the coordination chemistry of metal complexes with organic multidentate ligands containing pyrazole rings as well as pyrazole ligand because of their diverse coordination behaviors and relevance to a biologically active metal center with imidazole-like ligands. [1][2][3][4][5] Herein, we introduce a multidentate ligand, N,N,N¢,N¢-tetrakis(3,5-dimethyl-1-pyrazolyl)methyl-1,4-phenylenediamine (tpmp), which has a linear backbone of 1,4-phenylenediamine moiety. 6 These kinds of multidentate organic ligands are interesting, because linear backbone may serve as a spacer for an organic linking ligand or a multidentate chelating ligand, like 1,4-benzeneditetrazolate in coordination polymers. 7 In this study, we isolated a new dinuclear cobalt complex from a reaction of cobalt(II) chloride and tpmp, and determined the crystal structure of this compound, which consists of two tetrahedral cobalt(II) atoms with two pyrazolato-nitrogen atoms of tpmp and two chloride atoms, as shown in Fig. 1

Tetranuclear Nickel(II) and Cobalt(II) Complexes with 3,5-Dimethyl-1-pyrazolylmethanolato and Acetato Bridges Having a Cubane Core

“…[1][2][3][4][5][6][7][8] Recently, we studied metal complexes with a multidentate ligand, N,N,N¢,N¢-tetrakis(3,5-dimethyl-1-pyrazolyl)methyl-1,4-phenylenediamine (tpmp), having the 1,4-phenylenediamine moiety, and isolated a dinuclear cobalt complex from a reaction of cobalt(II) chloride and tpmp consisting of two tetrahedral cobalt(II) atoms with two pyrazolato-nitrogen atoms of tpmp and two chloride atoms. 6 In this study, we tried to extend this work to reactions with other metal salts, such as cobalt(II) acetate and nickel(II) acetate. We found totally different products with 3,5-dimethyl-1-pyrazolyl)methanolato (dmpm -), as shown in Fig …”