EFFECT OF SUBSTITUTION ON PACKING IN OBENZOATO-O)-DI(1,3-DIAMINOPROPANE-N,N')NICKEL(II) (Z = 2, 3 OR 4) COMPLEXES

The structures of obenzoato-O)bis(1,3-diaminopropane-N,N')nickel(II) ( where Z=2,3 or 4) were determined by single-crystal X-ray methods. In each compound the chelate rings display a chair conformation and there is trans coordination around the central metal cation. The coordinati on polyhedron around the central nickel(II) cation is distorted pseudo -octahedron with the site symmetry of C-i. Although the bond lengths a nd angles in the compounds are similar, there are differences in the p acking modes. The hydrogen bonding networks combine the complex units in two dimensions. However, there is notable variation in the third di mension, where the position of a chlorine substituent in an aromatic r ing determines the packing mode of the benzoate anions. The crystal da ta are as follows. [Nitn(2)(2ClbzO)(2)], C20H28Cl2 N4NiO4, M-r=518.08, orthorombic, space group Pbca No. 61, a=10.219(3), b=10.247(2), c=22. 336(7) Angstrom, Z=4. [Ni(tn)(2)(3ClbzO)(2)], C20H28Cl2N4NiO4, M-r=518 .08, monoclinic, space group P2(1)/a No.14, a=11.555(2), b=8.162(2), c =12.650(2) Angstrom, beta=106.17(2)degrees, Z=2. [Ni(tn)(2)(4ClbzO)(2) ], C20H28Cl2N4NiO4, M-r=518.08, monoclinic, space group P2(1)/c No. 14 , a=10.538(3), b=9.099(2), c=12.801(3) Angstrom, beta=92.83(2)degrees, Z=2; tn=1,3-diaminopropane, bzO=a benzoate anion. (C) 1998 Elsevier S cience S.A.