“…Thus, the number, kind and strength of hydrogen bonds formed by [Co(1)(en)3 ]3+ differs from that formed by [Co(2)(en)3] 3+. A common feature for both is that iodide anions are bonded to -NH(ob) groups, in agreement with the steric criterion of Raymond, Corfield & Ibers (1968) developed by Spinat, Whuler & Brouty (1979). On the other hand, it can be assumed that the presence of four base sites in the planar oxalate anions makes possible the stabilization of A666 or A222 configurations instead of other configurations, such as A2,;t2 or A66~, which are usually stabilized when an extensive hydrogen-bonding network exists (Haque, Caughlan & Emerson, 1970;Duesler & Raymond, 1971;Cramer & Huneke, 1978).…”