Abstract The I. R. measurements on a series of complexes, prepared with copper (II) phthalimide and aliphatic amines of type [Cu(amine)2 · (Phthalimide)2]0 have been done. The spectra indicate that the co‐ordination of phthalimide ion to copper may be through the nitrogen and that the arrangement of two amine and two phthalimide ions around the copper atom may be trans planar.