Structure and magnetic studies of bis‐piperidinium tetrachlorocuprate

X‐ray, magnetic susceptibility, and epr investigations of bis‐piperidinium tetrachlorocuprate (C5H10NH2)2CuCl4 indicate that it is a complicated structure of CuCl4= chains and ribbons separated by piperidinium groups and that it exhibits weak antiferromagnetism with J/k approximately −0.8 °K. The space group is Pc and the unit cell data are a=8.218 A, b=16.924 A, c=12.186 A, and β=100.5°. The possibilities of magnetic dimensionality transitions and disordering as a function of temperature are discussed.