3224THE CRYSTAL AND MOLECULAR STRUCTURE OF C35H4sO 5 clustered, the trend of a decreasing C-O bond length with decreasing bridge angle is clearly evident.A packing diagram is shown in Fig. 6. In general the long direction of the molecules lies perpendicular to the b axis with the longest dimension of the molecules lying along the diagonal of the ac plane. No unusual intermolecular contacts were observed. The

Abstract.[Cu(C loH9N3)(C 2H302)(C104)1. H20, C 12H 14-ClCuN30 7, M r = 411.3, monoclinic, P21/c, Z = 4, a = 7.309 (3), b = 16.363 (4), c = 13.646 (4)/k, /~ = 105.-085 (3) ° , U = 1589.65/~3 Dm= 1.75 (2), D c = 1.72 Mg m -3. R = 0.0517 for 2518 observed 'reflections. The local molecular CuN2020; chromophore involves an elongated rhombic octahedral structure with near symmetrically bonded di-2-pyridylamine (dpyam) and acetate groups bonding in the plane and bridging semi-coordinate perchlorate groups completing the six coordination.

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The anation of p-ci~-[Co(trien)(OH~)~]~+ ion by oxalic acid, bioxalate anion and oxalate dianion has been studied at 30-45°C and I = 1.0 M (KNO,). The common anation rate constant, k,, of {~-cis-[C~(trien)(OH,)~]~+. H,C?O,} and {p-~is-[Co(trien)(OH,)~]~+, HC20T} ion-pairs is found to be 6.7 x sec-' at 40°C. The observed anation rate constant levels off to a,limiting value (7.0 (20.8) x sec-I) at 40"C, pH = 4.00 (20.05) and [CzO:-] 3 0.15 M, which is characteristic of the anation rate constant (k,) of the oxalate dianion ion-pair. Activation enthalpy and entropy for the k , and kl paths are 24.5 K.cal mole-', 0.8 cal. deg-I mole-' and 28.9 K.cal mole-], 24.0 cal. deg-mole-', respectively. The temperature independent ion-pair equilibrium constant for H2C20, ion-pair was found to be 6.8 (21.2) M-'. The anation of {~-cik-[C~(trien)(OH~)~]~+-X} ion pairs (X = H2C20,, HC,O; or C20,2-) is believed to involve an 'Id' mechanism.

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