No abstract

Magnetische und spektroskopische Untersuchungen der Titelkomplexe zeigen, daß Grad und Art ihrer Polymerisation mit der Substitution am Biguanid‐Teil variiert.

A study of the magnetic properties (80-31 0 K) of the complexes [ C U ~( O , C C ~H , R ) ~] * ~, ~N H -O ~ (R = H, rn-Me, or o-NO, ; 3.6NH-od = 3,6-diazaoctane-I ,8-diamine) indicates the presence of ferromagnetic interactions. In the cases of R = H and rn-Me, feeble ferromagnetism appears in the range 80-1 50 K. The o-nitrobenzoato-complexshows only antiferromagnetic interactions leading to diamagnetism in the 80-1 50 K region. Comparison of the experimental and calculated susceptibilities with the Bleaney-Bowers model with -2J = 289.2 cm-l for R = H. 31 1.4 cm-l for R = m-Me, and 265.6 cm-l for R = o-NO, (in each case g = 2.1 9 and N = 60 c.g.s. units), indicates that the complexes are polymeric with three binuclear units of benzoatocopper(ii) joined by two 3,6NH-od molecules. A spectral band in the 333-425 nm region indicates the presence of metal-metal interactions. Lowering of a band at 1 695 c m -l to 1 620-1 640 c m -l is indicative of carboxylate bridging, and a band in the 800-820 cm-l region is attributed to M-N co-ordination.