Inorganic Chemistry, Vol.34, No.2, 454-465, 1995
Polynuclear Copper Lanthanide Complexes with Amino Alcohol Ligands - Syntheses, Structures, and Magnetic and Spectroscopic Studies of Cuii(Bdmmp)2(H2O), Priiicuii(Bdmmp)(Bdmmph)(Mu-Oh)(Hfacac)3, (Laiiicuii(Bdmmp)(Bdmmph)(Mu-Oh)(O2Ccf3)3)2, and Cuii4(Bdmmp)2(Mu-4-O)(O2Ccf3)4, (Bdmmph = 2,6-bis((Dimethylamino)Methyl)-4-Methylphenol - Hfacac = Hexafluoroacetylacetonato)
The syntheses of polynuclear copper(II)-lanthanide(III) complexes using the 2,6-bis[(dimethylamino)methyl]-4-methylphenolato ligand (bdmmp) have been investigated. The reaction of Cu(OCH3)2 with 2 equiv of bdmmpH in THF yields a mononuclear copper complex Cu(bdmmp)2(H2O) (1), which subsequently reacts with 1 equiv of Pr(hfacac)3 or La(O2CCF3)3 (hfacac = hexafluoroacetylacetonato) to produce two heteronuclear complexes Pr(III)-Cu(II)(bdmmpH)(OH)(hfacac)3 (2) and [La(III)Cu(II)(bdmmp)(bdmmpH)(OH)(O2CCF3)]2 (3). The reaction of Cu(OCH3)2, Cu(O2CCF3)2, bdmmpH, and H2O in a 1:1:1:0.5 ratio in THF yields a tetranuclear copper complex Cu4(bdmmp)2(mu4-O)(O2CCF3)4 (4). The structures of compounds 1-4 have been determined by single-crystal X-ray diffraction analysis. Compound 1 crystallizes in the monoclinic crystal space group C2/c, with a = 17.443-(8) angstrom, b = 9.510(3) angstrom, c = 20.459(9) angstrom, beta = 122.89(3)-degrees, V = 2849(2) angstrom3, and Z = 4. Compound 2 crystallizes in the monoclinic space group P2(1)/n, with a = 14.304(8) angstrom, b = 19.122(6) angstrom, c = 20.059(4) angstrom, beta = 100.21(3)-degrees, V = 5399(3) angstrom3, and Z = 4. Compound 3 crystallizes in the triclinic space group P1BAR, with a = 13.106(6) angstrom, b = 17.15(1) angstrom, c = 11.152(6) angstrom, alpha = 97.14(4)-degrees, beta = 108.48(4)-degrees, gamma = 93.85(4)-degrees, V = 2343(2) angstrom3, and Z = 1. Compound 4 crystallizes in the orthorhombic space group P2(1)2(1)2(1), with a = 18.408(7) angstrom, b = 22.88(1) angstrom, c = 10.598(5) angstrom, V = 4464(2) angstrom3, and Z = 4. The magnetic properties of these compounds have been examined by variable-temperature magnetic susceptibility measurements. The magnetism of compound 2 is dominated by the paramagnetism of the Pr(III) ion, while the magnetism of 4 is dominated by antiferromagnetic exchanges of the Cu(II) ions with J1 = -101 cm-1, J2 = -101 cm-1, J3 = -45 cm-1, J4 = 3 cm-1, and g = 2.02. UV-vis spectroscopic studies revealed that compound 1 has an intense ligand --> metal charge transfer band at lambda = 427 nm. Molecular orbital analysis on the electronic structure of 1 by extended Huckel MO methods indicates that this absorption band is mainly due to the transitions of the pi orbitals of the phenoxy ligand to the singly occupied dx2-y2 orbital of the copper ion.
Keywords:CRYSTAL-STRUCTURE;METAL