Crystallochemical formula as a tool for describing metal–ligand complexes – a pyridine-2,6-dicarboxylate example

Abstract

Compounds (299) containing 494 symmetrically independent pyridine-2,6-dicarboxylate moieties have been investigated. Among them the structures of Na(3)[Nd(Pydc)(3)].14H(2)O and Na(3)[Er(Pydc)(3)].11.5H(2)O, where H(2)Pydc is pyridine-2,6-dicarboxylic acid, were determined by single-crystal X-ray diffraction, while the others were taken from the Cambridge Structural Database. The characteristics of any complex by means of the ;method of crystallochemical analysis' are described, and the coordination types of all the Pydc ions and crystallochemical formulae of all the compounds were determined. Although the ion can act as a mono-, bi-, tri-, tetra- and pentadentate ligand, 96% of Pydc ions are coordinated to the central A atom in the tridentate-chelating mode. The dependence of the denticity and geometry of pyridine-2,6-dicarboxylate, as well as of the composition of Pydc-containing complexes, was studied as a function of the nature of the A atom, the molar ratio Pydc:A and the presence of neutral or acidic ligands in the reaction mixture.

Structures, luminescence and vibrational spectroscopy of europium and terbium nitro- and dinitro-substituted benzoates. Nitro groups as quenchers of Ln3+ luminescence

“…Here and below coordination type of a ligand is denoted in terms of Ref. [27]. All these types are met in the structures of nitrobenzoates.…”

Structure and optical spectroscopy of Yb(III) complex with o-phenylenedioxydiacetic acid

“…These kinds of tridentate carboxyl groups coordination (II and V) are rarely found in polymeric structures of lanthanide complexes containing the Na(I) ion. The carboxyl group coordination of II and V type was reported in [33][34][35], type II in [36][37][38], and type V in [39][40][41][42][43]. 1571 cm À1 (m as (COO À )).…”

Exploitation of knowledge databases in the synthesis of zinc(II) malonates with photo-sensitive and photo-insensitive N,N′-containing linkers

“…Coordination modes are denoted in accordance with the nomenclature described by Serezhkin et al (2009). Each ligand L is designated by one of the letters M, B, T or K depending on the number of donor atoms connected to the metal (1, 2, 3 or 4, respectively).…”