Structure and magnetism of NNN′N′-tetramethyl-p- phenylenediamine-pentacyanocyclopentadienide (TMPD-PCCp)

Abstract

TMPD-PCCp crystallizes in the triclinic space group P1 with cell parameters a = 6.814(2), b = 10.595(3), c = 14.540(3) Å, α = 74.65(2), β = 81.93(2), γ = 79.04(2)°, V = 989.3 Å3, Z = 2, and wR = 0.064. The complex exhibits novel mixed stacking of TMPD+ ion radicals and diamagnetic PCCp- ions and is weakly antiferromagnetic, with a Weiss constant of 2.6 K. An empirical model for ferromagnetic superexchange is presented for properly oriented ion radicals forming mixed stacks with symmetric diamagnetic spacers. © 1986 American Institute of Physics.