Dinuclear copper(II) complexes containing nitroso-oximato bridges: two different copper(II)-bridging entities from the same precursor

Content Provider	Semantic Scholar
Author	Dominguez-Vera, José M. Colacio, Enrique Escuer, Albert Klinga, Martti Kivekäsc, Raikko Romerosa, Antonio
Copyright Year	1997
Abstract	Abstract The complexes [Cu(μ-L)Cu(bipy)(EtOH)](ClO4)2 2a and [Cu(μ-1L)Cu(bipy)(H2O)](ClO4)2·H2O 2b [where H2L = N,N′-bis(1,3-dimethyl-5-nitrosopyrimidine-2,4-(1H,3H)-dion-6-yl)propylenediamine; H21L arises from H2L by elimination of a CO molecule from one of the pyrimidine rings] have been obtained from the reaction of the precursor [Cu(μ-HL)Cu(H2O)2(CH3CH2OH)](ClO4)3 1 with bipy and Cu(ClO4)2 · 6H2O, respectively. The structures of 2a and 2b have been solved by X-ray crystallographic methods. The structure of 2a is made up of [Cu(μ-L)Cu(bipy)(EtOH)]2+ cations and two semi coordinated perchlorate anions. The [Cu(I)L] fragment coordinates to the external Cu(2) ion through the two deprotonated oximate oxygens to afford a dinuclear structure with double syn-syn nitroso-oximate bridge and an intramolecular CuCu distance of 3.731(1) A. The Cu(1) exhibits a CuN4O2 pseudoctahedral coordination polyhedron whereas the geometry around the Cu(2) ion is distorted square-pyramidal CuN2O2O. The structure of 2b consists of [Cu(μ-1L)Cu(bipy)(H2O)]2+ cations, two perchlorate anions and one lattice water molecule. The coordination of the [Cu(1L)] unit to the external Cu(2) ion takes place through the two nitroso-oximate groups, one of them disordered on two sets of crystallographic positions, one with a 63% occupancy and the other with a 37% occupancy. The intramolecular Cu(l)Cu(2) distance is 3.655(3) A. The Cu(l) occupying the inner site of the 1L2− ligand exhibits a 4+1 CuN4O (63%) [CuN3O2(37%)] coordination environment whereas the Cu(2) atom is in a distorted square-pyramidal CuN2O3(63%)[CuN3O2(37%)] environment. The dinuclear fragments of 2a and 2b are almost planar with dihedral angles between the mean basal coordination planes of 4.1(2)° and 4.6°, respectively. Both 2a and 2b are diamagnetic at room temperature, so that J
Starting Page	281
Ending Page	289
Page Count	9
File Format	PDF HTM / HTML
DOI	10.1016/0277-5387(96)00265-3
Volume Number	16
Alternate Webpage(s)	http://hera.ugr.es/doi/15004156.pdf
Alternate Webpage(s)	https://doi.org/10.1016/0277-5387%2896%2900265-3
Language	English
Access Restriction	Open
Content Type	Text
Resource Type	Article