939972-35-7Relevant academic research and scientific papers
Square-planar N2S2NiII complexes with an extended π-conjugated system
Kawamoto, Tatsuya,Takeda, Kazunori,Nishiwaki, Masato,Aridomi, Takashi,Konno, Takumi
, p. 4239 - 4247 (2007)
The reaction of a mixture of 2-(1-naphthyl)benzothiazoline (HL1) and 2,6-diphenylbenzo[1,2-d:4,5-d′]bisthiazoline (H3L 2) with nickel(II) acetate tetrahydrate yielded three kinds of square-planar nickel(II) complexes: one nickel(II) complex with innocent ligands ([Ni(L1)2] (1c)) and two nickel(II) complexes with non-innocent ligands ([Ni(L1-L1)] (1a) and [Ni(L 1-L2)] (1b)). The complex 1c has two bidentate-N,S ligands, which are formed via ring opening of HL1. On the other hand, the two complexes 1a and 1b contain a tetradentate-N2S2 ligand, which is created via ring opening of HL1 and H 3L2, followed by bond formation between imino carbon atoms. Complexes 1a and 1b show very intense absorptions in the near-infrared (NIR) region, characteristic of square-planar complexes with non-innocent ligands. The third nickel(II) complex having a non-innocent tetradentate-N 2S2 ligand ([Ni(L2-L2)] (2)) was prepared from H3L2 and nickel(II) acetate tetrahydrate. The electronic spectrum of 2 exhibits a very intense absorption at 981 nm (ε = 3.6 × 104 M-1 cm-1), which is significantly red-shifted compared with those of 1a (837 nm and 4.4 × 104 M-1 cm-1) and 1b (885 nm and 4.5 × 104 M-1 cm-1), indicating the presence of an extended π delocalization. The reaction of 2,6-bis(3,5-dichlorophenyl) benzo[1,2-d:4,5-d′]bisthiazoline (H3L3) with nickel(II) acetate tetrahydrate also led to the formation of a nickel(II) complex with a non-innocent ligand ([Ni(L3-L3)] (3)). While complex 3 is analogous to 2, its electrical conductivity is much higher than that of 2. The molecular structures of 1b, 1c, 2, and 3 were determined by X-ray crystallography.
