The crystal structure of a bis(2,6-pyridinedicarboxylato)chromate(III) anion with an elaborate network of hydrogen bonding and π stacking

Chromium, molybdenum and tungsten

“…The synthesis, X-ray crystallography, spectroscopic, and electrochemical properties of [Hdpa][Cr(dipic) 2 ] Á 3H 2 O have been reported. 56 Based, on X-ray crystallography, the distorted octahedral [Cr(dipic) 2 ] À anions are part of an elaborate network of hydrogen bonding formed by the waters of solvation, the anion, and cation as well as p-stacking interactions. 56 It has been reported that lattice nitrogen within the catalyst Co 3 Mo 3 N was both reactive and likely highly mobile, 57 enabling potential novel nitrogen transfer pathways, where it has been suggested that loss and subsequent recovery of lattice nitrogen in the system reversibly cycles through the previously unknown nitride, Co 6 Mo 6 N. 57 Oxygen-, sulfur-, and selenium-bonded complexes…”

Potassium (4-carboxypyridine-2,6-dicarboxylato)dioxidovanadate(V) monohydrate

“…For related literature, see: Cassellato & Vigato (1978); Cingi et al (1971); Crans et al (2000); ; D'Ascenzo et al (1978); Drew et al (1970); Dutta & Ghosh (1967); Furst et al (1978); Gaw et al (1971); Ghosh et al (1978); Lukes & Jurecek (1948); Murtha & Walton (1973); Payne et al (2007); Syper et al (1980); Yang et al (2002). Selected bond lengths (Å ).…”

“…Pyridine-2,6-dicarboxylic acid (dipicolinic acid, abbreviated as H 2 dipic) has been found to be an interesting and versatile ligand for several reasons: (1) it can function as a tridentate ligand; (2) the carboxylate groups sometimes bridge two metal atoms (Cingi et al, 1971); (3) coordination to a metal atom can occur through dianionic (dipic 2-) (Lukes & Jurecek, 1948, Dutta & Ghosh, 1967, Drew et al, 1970, monoanionic (Hdipic -) (Murtha & Walton, 1973, Gaw et al, 1971, or neutral (H2dipic) forms of this ligand (Drew et al, 1970). Based on these facts, a large number of divalent or trivalent transition metal and lanthanide(III) complexes of dipicolinic acid have been studied (Payne et al, 2007, Cassellato & Vigato, 1978, D′Ascenzo et al, 1978, Ghosh et al, 1978, Furst et al, 1978. Recently, a number of cobalt-and vanadiumcontaining complexes with either 4-hydroxypyridine-2,6-dicarboxylic acid or dipicolinic acid as ligand, were reported to be insulin-like in nature , Crans et al, 2000, Yang et al, 2002.As part of our interest in the coordination chemistry of analogues of dipicolinic acid, we now extend this chemistry to include the structural elucidation of the [VO 2 (dipic-CO 2 H]anion.…”