Preparation and structure of tetrakis(indolo[2,3-b]quinoxalinato)dinickel(II)

Treatment of 6H-indolo[2,3-b]quinoxaline (1) with NaBH4 in ethanol at 82 de grees C for 10 min under argon gives the reactive anion species 2 (generate d by deprotonation of N-6 position of 1), which upon reaction with Ni(OAc)( 2). 4H(2)O in ethanol at 82 degrees C for 6 h under argon forms the title d inuclear nickel(II) complex 3. The molecular structure of the novel complex 3, indicating the Ni-Ni distance of 2.618(1) Angstrom, is reported.