Structures of Pyridine Carboxylate Complexes of Cobalt(ii) and Copper(ii)

New thallium(III) chloride complexes with pyridine carboxylic acids: from molecular compounds to supramolecular associations

“…A survey of the reported molecular structure determinations for metal complexes reveals that the O,Nmonometallic biconnective (bidentate) (Scheme 1, structures I and II) is the most usual coordination pattern for the deprotonated form of the picolinic (Hpic) and 3-hydroxypicolinic (H3hpic) acids [1,2,3,4]. Nicotinic (Hnic) and isonicotinic (Hinic) acids were found to coordinate: (i) as unidentate, neutral ligands only through the pyridyl nitrogen atom (Scheme 1, structures IIIa and IVa) [5,6], (ii ) as O,O-bimetallic biconnective (bridging) ligands (Scheme 1, structures IIIb and IVb) [7,8], and (iii ) as O,O; N -bimetallic triconnective (tridentate) groups (Scheme 1, structures IIIc and IVc) [9,10]. The presence of the carboxylate group as substituent in position 2 of the pyridine ring usually leads to O,N -monometallic biconnective (chelate) coordination, while substitution in position 3 or 4 promotes the formation of supramolecular associations through bridging ligands.…”

Growth and characterisation of a novel polymer of manganese(II) nicotinate single crystal

“…In the case of Mn(II) complex of 2-mercaptonanicotinic acid, the Mn(1) ÀO distance range from 2.115(2) to 2.201(2) where as the Mn(1) À N distance is from 2.150(1) to 2.233(2) [14]. However in the case of cobalt and copper complexes, the metal atoms are coordinated by two pyridine nitrogen and four water molecules in which there is no -COO À coordination [15].…”

Chromium(III)-isonicotinate Complexes. Kinetics and Mechanism of Isonicotinate Ligand Liberation in HClO4 Solutions

“…The determined crystal structures for some Co(II), Mn(II), Cu(I), Cu(II), Ag(I), Pt(II) complexes demonstrate that isonicotinic acid is bonded via the pyridine nitrogen atom [6][7][8][9][10][11]. In the case of lanthanide complexes, isonicotinic acid acts as a bridging and chelating ligand through its carboxylate group [12,13].…”