Tetra-μ-aqua-octaaquabis(μ-4-chloropyridine-2,6-dicarboxylato)bis(4-chloropyridine-2,6-dicarboxylato)tricobalt(II)disodium(I) bis[triaquabis(4-chloropyridine-2,6-dicarboxylato)cobalt(II)] hexahydrate

Abstract

The title compound, [Co3Na2(C7H2ClNO4)4(H2O)12][Co(C7H2ClNO4)(H2O)3]2·6H2O, consists of a centrosymmetric dimer of [CoII(dipicCl)2]2− complex dianions [dipicCl is 4-chloro­pyridine-2,6-dicarboxyl­ate] bridged by an [Na2CoII(H2O)12]4+ tetra­cationic cluster, two independent [Co(dipicCl)(H2O)3] complexes, and six water mol­ecules of crystallization. The metals are all six-coordinate with distorted octahedral geometries. The [CoII(dipicCl)(H2O)3] complexes are neutral, with one tridentate ligand and three water molecules. The [CoII(dipicCl)2]2− complexes each have two tridentate ligands. The [Na2CoII(H2O)12]4+ cluster has a central CoII ion which is coordinated to six water molecules and lies on a crystallographic inversion center. Four of the water molecules bridge to two sodium ions, each of which have three other water molecules coordinated along with an O atom from the [CoII(dipicCl)2]2− complex. In the crystal structure, the various units are linked by O—H⋯O hydrogen bonds, forming a three-dimensional network. Two water molecules are disordered equally over two positions.

Computational, electrochemical, and spectroscopic studies of two mononuclear cobaloximes: the influence of an axial pyridine and solvent on the redox behaviour and evidence for pyridine coordination to cobalt(i) and cobalt(ii) metal centres

“…In these systems, para-substituted pyridine linkers have been employed as important templates in the syntheses of photocatalytic systems reported for the reduction of protons to form hydrogen. 44,62,63 For many years, we have been interested in the development of transition metal complexes that contain at least one cobalt metal centre, 44,[64][65][66][67][68][69][70][71] and also inorganic reaction mechanisms that involve electron transfer processes. 64,65,[72][73][74] Recently, 44 [Ru(Me 2 bpy) 2 (L-pyr)Co-(dmgBF 2 ) 2 (OH 2 )](PF 6 ) 2 (where Me 2 bpy = 4,4′-dimethyl-2,2′bipyridine), and [Ru( phen) 2 (L-pyr)Co(dmgBF 2 ) 2 (OH 2 )](PF 6 ) 2 for hydrogen evolution in acidic acetonitrile.…”

Assessing the stability of the Co(I) species of two mononuclear dichlorocobalt compounds bearing 2,2′-bipyridine and trans-2-(2′-quiolyl)methylene-3-quinuclidione via 59Co NMR spectroscopy, electrochemical, and catalyzed proton electroreduction studies

“…Our research group and collaborators have been interested in the development of transition metal complexes that contain cobalt metal centres [24][25][26][27][28][29][30][31], as well as inorganic reaction mechanisms that involve electron transfer processes [25,26,[32][33][34][35][36]. In a recent report, we outlined the preparation and application a novel mixed-metal binuclear ruthenium(II)-cobalt(II) photocatalysts ([Ru(pbt) 2 (Lpyr)Co(dmgBF 2 ) 2 (H 2 O)](PF 6 ) 2 (where pbt = 2-(2′-pyridyl)benzothiazole, L-pyr = (4pyridine)oxazolo [4,5-f]phenanthroline, and dmgBF 2 = difluoroboryldimethylglyoximato) for photocatalytic production of hydrogen [24].…”