Bis(pyrimidine-2-carboxylato-κ²N,O)copper(II)

Abstract

Key indicators: single-crystal X-ray study; T = 291 K; mean (C-C) = 0.003 Å; R factor = 0.025; wR factor = 0.072; data-to-parameter ratio = 13.6.The title compound, [Cu(C 5 H 3 N 2 O 2 ) 2 ], was prepared in a water-ethanol solution containing 2-cyanopyrimidine, malonic acid and copper(II) nitrate trihydrate. The Cu II ion, located on an inversion center, is chelated by two pyrimidine-2-carboxylate anions in a CuO 2 N 2 square-planar geometry. The uncoordinated carboxylate O atom and pyrimidine N atoms are linked to adjacent pyrimidine rings via weak C-HÁ Á ÁO and C-HÁ Á ÁN hydrogen bonding. -Stacking is observed between nearly parallel pyrimidine rings, the centroid-to-centroid separation being 3.8605 (13) Å . Related literature ExperimentalCrystal data [Cu(C 5

Thermal, spectroscopic, X-ray and theoretical studies of metal complexes (sodium, manganese, copper, nickel, cobalt and zinc) with pyrimidine-5-carboxylic and pyrimidine-2-carboxylic acids

“…In the sodium pyrimidine-2-carboxylate spectra, it was observed that for many bands originating from vibrations of the aromatic system and the wavenumber (3,4,5,6,13) are reduced. Many of the bands present in the ligand spectrum disappear in the spectrum of sodium salt (8,12,14,17,18,20,22). Some of the bands do not change (7,9,10,16), and only for some bands, the wavenumbers increase in the spectrum of the sodium salt with respect to the ligand (11,21,23).…”

“…In the spectrum of sodium salt, a number of bands present in the spectrum of acid disappear. These are bands marked with 4,5,7,8,9,11,12,17,18,21). Some of the bands are shifted toward the lower values of wave numbers in the spectrum of sodium salt (13,22).…”

“…In complexes of heteroaromatic acids, the metal may be attached via a carboxyl anion and heteroatoms of the aromatic ring. These types of binding are formed inter alia in the pyridine-2-carboxylic, pyrazine-2-carboxylic or pyrimidine-2-carboxylic acid complexes [15][16][17][18]. The pyrimidine-5-carboxylic acid may form complexes by attaching a metal via a ring nitrogen atom without the participation of a carboxylic group [19].…”

“…Carboxylic acids derived from diazines ( Fig. 1) due to the number of potential chelating sites can form various coordination structures in relationships with metal ions [18,19,31,32]. The pyrimidine derivatives are found in living organisms where they play a fundamental role in many life processes.…”