Di-μ-chloro-bis[aqua(caffeine)chlorocopper(II)]

Abstract

The title compound, di‐μ‐chloro‐bis­[aqua­chloro­(3,7‐dihydro‐1,3,7‐trimethyl‐1H‐purine‐2,6‐dione)copper(II)], [Cu2Cl4(C8H10N3O2)2(H2O)2], has the same chemical empirical formula as another compound [Bandoli et al. (1976). Inorg. Chim. Acta, 20, 71–78]. However, the title compound is a dimer arranged around an inversion centre, whereas Bandoli's compound is a chiral polymer. In the title compound, the CuII atom has a distorted tetra­gonal pyramidal coordination, formed by three Cl atoms, one N atom of the caffeine ligand and one O atom of a water mol­ecule.

Detection of Binuclear Copper—Caffeine Complexes under Electrospray Ionization Condition

“…[12][13][14][15][16] However, detection of binuclear copper-caffeine complexes could be a problem because ESI conditions (concentration about 10 -5 mol dm -3 , usually methanol as solvent and then a complicated process of the transfer of ions from solution to the gas phase) are much different from those used to prepare the complex for crystallographic characterization (often saturated solution is used and heated to boiling temperature). [6][7][8][9][10][11] this paper shows which of the binuclear copper-caffeine complexes can be detected by ESI-MS. If they are detected, this means that binuclear complexes are present in the electrosprayed solution and successfully transferred to the gas phase (formation of such complexes during phase transfer is rather unexpected).…”

“…[2][3][4][5] A number of binuclear copper-caffeine complexes have recently been characterized by crystallographic methods. [6][7][8][9][10][11] As expected from the well-known theory of hard and soft acids and bases, in most cases, the copper atom is co-ordinated by an N-9 nitrogen atom. [7][8][9][10][11] two copper atoms are usually bridged by carboxylate groups [6][7][8][9][10] and copper atoms are rarely bridged by chloride anions.…”

“…[7][8][9][10][11] two copper atoms are usually bridged by carboxylate groups [6][7][8][9][10] and copper atoms are rarely bridged by chloride anions. 11 Electrospray ionization mass spectrometry (ESI-MS) is well-known to be a suitable tool to study metal complexes with organic molecules. [12][13][14][15][16] However, detection of binuclear copper-caffeine complexes could be a problem because ESI conditions (concentration about 10 -5 mol dm -3 , usually methanol as solvent and then a complicated process of the transfer of ions from solution to the gas phase) are much different from those used to prepare the complex for crystallographic characterization (often saturated solution is used and heated to boiling temperature).…”

Synthesis and Structural Explanation of Mixed Ligand Complexes of Selenium(iv) With Caffeine and Some Nitrogen-Based Ligands

“…The metal complexes are monomeric, dimeric, several correlations are stabilized and discussed for coordination of caffeine and derivatives [13]. The Re(I) [14], Cu(II) [15], Zn(II) [16], Au(III) [17], Cu(II) and Zn(II) complexes of caffeine and xanthine compounds [18,19] have been synthesized and the structures as well as biological efficiency were assigned [20][21][22]. The caffeine, xanthines and theophylline organic ligands in usual neutral case are coordinated to different metal ions through N( 9) donating atom [10][11][12][13][14][15][16][17][18][19][20][21][22].…”

“…The Re(I) [14], Cu(II) [15], Zn(II) [16], Au(III) [17], Cu(II) and Zn(II) complexes of caffeine and xanthine compounds [18,19] have been synthesized and the structures as well as biological efficiency were assigned [20][21][22]. The caffeine, xanthines and theophylline organic ligands in usual neutral case are coordinated to different metal ions through N( 9) donating atom [10][11][12][13][14][15][16][17][18][19][20][21][22]. Herein, the scope of this study is aimed to synthesis, biological assessment and spectroscopic characterization of some mixed ligand complexes of caffeine and nitrogen base secondary ligands e.g.…”