Platinum group metal-ketoxime complexes: crystal structure of hydrogen fac-tris(dimethylviolurato)ruthenate(II) heptahydrate

Supramolecular interactions through lone pair(lp)–π and hydrogen bonding in cobalt(III) and manganese(II) derivatives of N,N′-dimethylvioluric acid: A combined experimental and theoretical study

“…In this complex, cobalt(III) atom is six-coordinated by three dimethylviolurato anions acting as bidentate ligands leading to a [CoN 3 O 3 ] chromophore in a fac disposition. This coordination mode has been previously observed in other metal complexes containing dimethylviolurato anions as ligands [22,40]. The coordination of each bidentate ligand forms a five-membered chelate ring, exhibiting very significant differences between the Co-N ($1.88 Å) and Co-O ($1.95 Å) distances.…”

“…Furthermore, there is a considerable number and diversity of applications of violurato derivatives, namely, in analytical chemistry (determination and identification of metal cations) [9], as potent bioactive molecules (antibacterial, antifungal, antihypoxic, antiproliferative and antitumor agents) [10] and redox mediators (e.g., in enzyme-catalyzed degradation of organic pollutants in the industrial effluents and bleaching treatment) [11]. Although various metal complexes of violuric acid [12][13][14][15][16][17][18] and N,N 0 -dimethylvioluric acid [19][20][21][22][23][24] have been reported, the investigation of energetic features of supramolecular assemblies observed in such structures has not been undertaken in detail. Very recently, some of our group have reported the structures of N,N 0 -dimethylvioluric acid monohydrate and two cadmium(II) complexes obtained from reactions involving HDMV and different N-donor ligands (benzimidazole and pyridine) [25] [27], have been reported previously.…”

Structural analogues of ferroverdin. Tris(methyl isonitrosoacetoacetato)cobalt(III)

“…Each ligand is bidentate, binding to the metal via the N atom of the nitroso group and the ketonic O atom, thereby forming a five-membered chelate ring. The disposition of the three ligands around the Co atom is fac, the overall geometry being very similar to that found in analogous compounds, not only with cobalt(III) (Figgis, Raston, Sharma & White, 1978b), but also with other d 6 metal ions, such as iron(II) (Raston, White & Golding, 1977) and ruthenium(II) (Romero, Salas, Simard, Quir6s & Beauchamp, 1990). The coordination octahedron is trigonally distorted, as would be expected for a tris-chelate complex.…”

Synthesis, Characterization, and Protonation of an Amide-Containing Thiolate Complex of a Ruthenium Nitrosyl Porphyrin

“…These values are within those expected (2.5-3.2 Å, 130-180°) for moderate hydrogen bonds. 54 Although dimethylformamide complexes of ruthenium porphyrins are known 35,55 and a few non-porphyrin ruthenium amide crystal structures have been reported, [56][57][58][59] to the best of our knowledge this is the first X-ray structural determination of a ruthenium porphyrin amide complex.…”