Divalent transition metal complexes [LM(II)](ClO4)(2) (M=Mn,Fe,Co,Ni,Cu,Pd) of the hexadentate ligand 1,4,7-tris(o-aminobenzyl)-1,4,7-triazacyclononane (L)

Reaction of the hexadentate ligand 1,4,7-tris(o-aminobenzyl)-1,4,7-triazacyclononane (L) in ethanol with perchlorate salts of divalent transition metal ions, M(II)(ClO4)(2) . 6H(2)O, affords crystalline salts [ML](ClO4)(2) (M: Mn, 1; Fe, 2; Co, 3; Cu, 5). The nickel complex 4 crystallizes as the monohydrate, [NiL](ClO4)(2) . H2O. The reaction of L with Pd(CH3CO2)(2) in ethanol gives red-brown crystals of [PdL](ClO4)(2) . H2O, 6, after addition of HClO4. The crystal structures of [NiL](ClO4)(BPh(4))(C3H6O)(2), 5, and 6 have been determined by single-crystal X-ray crystallography. [NiL](ClO4)(BPh(4))(C3H6O)(2) crystallizes in the triclinic space group <P(1)over bar> with Z = 2, a = 10.991(3) Angstrom, b = 13.817(6) Angstrom, c = 19.314(7) Angstrom, alpha = 77.19(3)degrees, beta = 77.99(2)degrees, and gamma = 72.80(3)degrees. The nickel ion is six-coordinate with a distorted octahedral NiN6 polyhedron; the cation possesses C-3 symmetry. Complex 5 crystallizes in the monoclinic space group P2(1)/n with Z = 4, a = 9.393(5) Angstrom, b = 17.16(1) Angstrom, c = 18.99(1) Angstrom, and beta = 92.70(5)degrees. The copper ion (d(9)) is five-coordinate with a square-based pyramidal CuN5 polyhedron; it contains one uncoordinated pendant o-aminobenzyl arm. A similar structure is adopted by the palladium(II) ion (d(8)) in 6; it crystallizes in the monoclinic space group P2(1)/n with Z = 4, a = 10.895(2) Angstrom, b = 18.578(4) Angstrom, c = 15.541(3) Angstrom, and beta = 93.41(2)degrees. X-ray powder diffraction data for 1-3 show that these salts are isostructural with the complex [ZnL](ClO4)(2), for which it has been shown previously that the zinc ion is in a distorted trigonal prismatic environment of six nitrogen donor atoms. Two of the six-membered aniline chelate rings adopt a boat whereas the third has a twist-boat conformation. The symmetry of the dications in 1-3 is therefore also C-1.