MULTISTEP REDOX SYSTEMS, LXIV - DCNQI ANION-RADICAL SALTS WITH BISAMMONIUM CATIONS

Radical-anion salts have been prepared by electrocrystallization from seven 2,3- and 2,5-disubstituted DCNQIs and the quaternary dications ( AMM(2+)) HMED, DMBP, EBP, and EBBT. The black compounds adopt the stoi chiometry DCNQI/dication = 3:1, The crystal-structure analysis of two of these radical salts reveal skewed (zigzag, trimerized) stacks of DC NQI molecules separated by sheets of dications. Specific interactions between DCNQI anions and dications are absent. The effect on the stack ing of the DCNQI units of the two positive charges in the dications wh ich are held apart at a defined separation is discussed. The salts are shown to be semiconductors with powder conductivities of 10(-2) to 10 (-5) cm(-1).