The favored trans(O-6) geometry in hexadentate copper(II) complexes of 1,3-propanediamine-N,N-diacetic-N,N-di-3-propionic acid. Crystal structure of trans(O-6)-Na-2[Cu(1,3-pddadp)]center dot NaNO3 center dot 2H(2)O. Strain analysis and spectral assignments of complexes

The octahedral copper(II) complexes of 1,3-propanediamine-N,N-diacetic-N,N-di-3-propionic acid (H(4)1,3-pddadp) prepared in the region of pH 2 to 7 are hexadentates. Only one (trans(O-6)) of the three geometrical isomers was found to dominate. The trans(O-6)-Na-2[Cu(1,3-pddadp)] . NaNO3 . 2H(2)O complex crystallizes in the space group P2/c of the monoclinic crystal system with a = 9.231(2), b = 11.736(14), c = 10.150(2) Angstrom, beta = 109.33(2)degrees and Z = 2. The conformations of the chelate rings are found to be envelope for the glycinate and skew-boat for the beta-alaninate and 1,3-propanediamine rings, The complex is a tetragonally elongated octahedron (T similar to 0.8) with C-2 molecular symmetry. IR (carboxylate region) and electronic absorption spectra are assigned and discussed in relation to the structure of complexes. For hexadentate Cu(II) edta-type complexes of known structures the strain analysis is also discussed

Synthesis and structure of aquamethanol-2,2-(2,6-pyridin-diyldiethylidene)-dioxamohydrazidocobalt(II) perchlorate

The complex [Co(H(2)L)(H2O) (MeOH)](ClO4)(2)[H(2)L] = 2,2triple prime-(2,6-pyridindiyl-diethylidene) -dioxamohydrazide] has been prepared by direct and template syntheses and characterized by elemental analysis, IR spectroscopy, and magnetic susceptibility measurements. The crystal structure of the complex has also been determined. The cobalt atom is seven coordinated with approximately pentagonal-bipyramidal geometry. The H2O and methanol are axial with the planar pentadentate H(2)L ligand forming the equatorial plane. The possible reaction mechanism has been proposed

Preparation and molecular structure of the trans(O-6) isomer of dihydrogen (1,3-propanediamine-N,N-diacetato-N,N-di-3-propionato)copper(II) complex. The stereochemistry of copper(II)-EDTA-type complexes in relation to the structure of the ligand

The hexadentate complex [Cu(H(2)1,3-pddadp)]. 1.5H(2)O (1,3-pddadp = 1,3-propanediamine-N,N-diacetate-N,N-di-3-propionate ion) has been prepared and isolated and its molecular structure determined by the single crystal X-ray diffraction technique. The complex is a trans(O-6) isomer, in which the copper(II) ion is surrounded octahedrally by two nitrogen and four oxygen atoms of 1,3-pddadp with two protonated beta-alaninate rings in trans positions. The copper atom environment is a tetragonally elongated octahedron with tetragonality (T) 0.798. A comparison of structures of the copper(II)-edta-type complexes shows an expected variation in their stereochemistry, depending on the structure of the ligand. The 1,3-pddadp ligand encircles the Cu-II ion more favourably than the edta ligand, which is capable of forming five-membered chelate rings only. Some properties of the complex are also given. Copyright (C) 1996 Elsevier Science Lt

Pentagonal bipyramidal complexes of Co(II) with singly- and doubly-deprotonated 2 ',2 '''-(2,6-pyridindiyldiethylidene)dioxamohydrazide - The crystal structure of [diaqua-2 ',2 '''-(2,6-pyridindiyldiethylidene)dioxamohydrazidecobalt(II)] hexahydrate

This paper reports the first Co(II) complexes with a singly-and doubly-deprotonated H2L ligand (H2L = 2',2'''-(2,6-pyridindiyldiethylidene)dioxamohydrazide belonging to the planar pentadentate class. The complexes were characterized by elemental analysis, thermal analysis, IR spectroscopy, molar conductivity and magnetic susceptibility measurements. The crystal structure of [Co(L)(H2O)(2)].6H(2)O complex has been determined. The pentagonal bipyramidal geometry present in the previously synthesized complex [Co(H2L)(H2O)(MeOH)](ClO4)2(,) wherein the ligand is present in a neutral form, has been preserved around Co(II)