Copper(II)–π interaction in cis-[Cu(orotato)(NH3)2] and the crystal structure of [Cu(orotato)(H2O)4]·H2O: X-ray, vibrational spectroscopy and density functional study

Vibrational spectra and reinvestigation of the crystal structure of a polymeric copper(II)–orotate complex, [Cu(μ-HOr)(H2O)2]n: The performance of new DFT methods, M06 and M05-2X, in theoretical studies

“…Metal ion coordination may occur through the two carboxylate O atoms as well as the two N atoms of the pyrimidine ring and two carbonyl oxygen atoms. Recently, our single crystal X-ray diffraction study on cis-[Cu(HOr)(NH 3 ) 2 ] has revealed the additional, unusual coordination site of the orotate ligand (HOr 2− ), namely, the (C C) bond of the uracilate ring [13]. Soylu et al [21] also reported a similar Cu-interaction in the dimeric complex, [Cu 2 (HOr) 2 (H 2 O) 4 ].…”

“…Similarly to the mononuclear Cu(II)-orotate complexes [13], the copper(II) ion is chelated by the carboxylate O1 oxygen atom and the deprotonated pyrimidine N1 nitrogen atom of the orotate ligand. Two oxygen atoms (O5 and O6) of two water molecules complete a slightly distorted square-planar environment of the copper atom.…”

“…Metal-orotates can penetrate the cell membranes, thus, they can be used in curing syndromes associated with a deficiency of calcium, magnesium, zinc, and iron [3][4][5]. The treatment with both vitamin B 13 and Mg-orotate gives excellent results in prevention and treatment of heart diseases [6]. It should be emphasized that copper-orotates are used as ingredients in pharmaceutical compositions for curing neoplastic disease [7] and compositions for treating skin, hair and nails [8].…”

“…In the last 10 years many research groups performed extensive studies on application of orotic acid as a polydentate ligand in coordination chemistry [9][10][11][12][13][14][15][16][17][18][19][20][21][22][23]. The multifunctionality of the orotate anions offers interesting possibilities for supramolecular assemblies in crystal engineering.…”

“…In a series of papers we reported detailed experimental and theoretical studies of the vibrational spectra and molecular structures of cis-[Ni(HOr)(H 2 O) 4 ]·H 2 O [11], cis-[Pt(HOr)(NH 3 ) 2 ] [12] cis-[Cu(HOr)(NH 3 ) 2 ] [13,14], and [Ni(HOr)(NH 3 ) 2 (H 2 O) 2 ] [15].…”