X-RAY CRYSTAL-STRUCTURE OF CU-2(MEDPCO-2H)CL-2, (MEDPCO=N,N'-BIS(2-N,N-DIMETHYLAMINOETHYL)PYRIDINE-2,6-DICARBOXAMIDE 1-OXIDE - COPPER(II) COMPLEXES OF A DEPROTONATED BINUCLEATING PYRIDINE N-OXIDE LIGAND

The X-ray structure is reported for the complex Cu-2(medpco-2H)Cl-2, (medpco=N,N'-bis(2-N,N-dimethylaminoethyl)pyridine-2,6-dicarboxamide 1-oxide. The complex is triclinic, <P(1)over bar>, a=8.313(4), b=11.403(5), c=11.611(3) Angstrom, a=91.66(3), beta=108.99(4), gamma=109.60(3)degrees and Z=2. The deprotonated ligand (medpco-2H)(2-) acts as a binucleating ligand, producing an N-oxide-bridged complex. Each copper in Cu-2(medpco-2H)Cl-2 is five-coordinate, being coordinated by a bridging N-oxide oxygen, a deprotonated amide nitrogen, a tertiary amine nitrogen and two bridging chlorides. The complex does not exhibit significant magnetic interaction, and this may be the result of distortion of the bridging geometry from planarity. A range of other, apparently N-oxide-bridged, complexes of the type Cu-2(medpco-2H)X(2) is reported. The complex Cu-2(medpco-2H)Br-2 . H2O is strongly antiferromagnetic, with magnetic data closely fitting the expected binuclear structure.