F. Albert Cotton, Lee M. Daniels, Glenn T. Jordan IV and Carlos A. Murillo
A crystallographic study of Co(dpa)2 reveals that the pseudo-tetrahedral molecules stack together to form a one-dimensional ribbon with the molecules linked together through significant C–H···N interactions; the C···N separation is 3.41(3) Å and the angle at the hydrogen atom is 177(2)°.