SYNTHESIS, SPECTRAL AND STRUCTURAL CHARACTERIZATION OF [NAMN(PYRAZINATO)(NCO)(2)(H2O)(2)], A POLYMERIC STRUCTURE CONTAINING MU(O,O,N)-BRIDGING CYANATO LIGANDS BETWEEN MANGANESE AND SODIUM-CENTERED POLYHEDRA

The complex [NaMn(pyrazinato) (NCO)(2)(H2O)(2)] has been synthesized a nd characterized by spectroscopic and X-ray crystallographic methods. The infrared and Raman spectral results suggest that the complex conta ins a N,O-bidentate pyrazinato anion, aqua ligands and Mn-O bonded cya nato groups. The structure of the complex features an octahedrally coo rdinated manganese atom as well as six-coordinated sodium atom. Each m anganese atom is chelated by a pyrazinato anion [via its ring nitrogen atom, Mn-N = 2.320(4) Angstrom, and a carboxylato oxygen atom, Mn-O = 2.175(3) Angstrom], and links a bridging aqua ligand [Mn-O = 2.284(3) Angstrom] and three mu(O,O,N)-bridging cyanato ligands [Mn-O from 2.1 44(4) to 2.307(4) Angstrom]. The sodium atom is bonded to three bridgi ng cyanato groups in a facial arrangement [Na-N(13) = 2.340(5) Angstro m, Na-N(23) = 2.368(4) Angstrom, and Na-O(11) = 2.584(4) Angstrom] and three water molecules [Na-O av. = 2.421 Angstrom] in which two of the m act as bridges between two sodium octahedra. The manganese and sodiu m octahedra have a common edge via an aqua ligand and a cyanato group. Copyright (C) 1996 Elsevier Science Ltd