14337-09-8Relevant academic research and scientific papers
Models for Copper-Dioxygen Complexes: the Chemistry of Copper(II) with Some Planar Tridentate Nitrogen Ligands
Piguet, Claude,Bocquet, Bernard,Mueller, Edgar,Williams, Alan F.
, p. 323 - 337 (2007/10/02)
The solution chemistry of Cu(II) with a series of five planar tridentate nitrogen ligands, 2,6-bis(benzimidazol-2-yl)pyridine (bzimpy, 1), 2,6-bis(1-methylbenzimidazol-2-yl)pyridine (mbzimpy, 2), 2,6-bis(benzothiazol-2-yl)pyridine (bzthpy, 3), 2,6-bis(benzoxazol-2-yl)pyridine (bzoxpy, 4), and 2,2',6',2"-terpyridyl (terpy, 5) is reported.Electronic and EPR spectra are consistent with the complexes 2+ having essentially tetragonal structure in solution, with the fourth coordination site in the plane of the ligand occupied by solvent. bzthpy and bzoxpy show smaller ligand-field splittings than bzimpy, mbzimpy, and terpy, and are easily decomplexed from the copper.Substitution of the coordinated solvent molecule in the plane of the ligand is observed with Cl- and OH- (provided that the ligand has no acidic protons) for all ligands except terpy.The reaction between 2+ and imidazole has been studied by potentiometric titration in MeCN/H2O 1:1 and shows strong binding of the imidazole in the plane (log K = 4.5 at 25 deg C), and also the formation of an imidazolate-bridged dinuclear species.
Detailed spectrophotometric study of copper(II) halides in anhydrous methanol
Khan,Meullemeestre,Schwing,Vierling
, p. 3306 - 3309 (2008/10/08)
A spectrophotometric study of the copper(II) chlorides and the copper(II) bromides in anhydrous methanol was carried out at 25°C and at constant ionic strength (1 mol·L-1). A matrix rank treatment of the experimental data followed by the testing of different theoretical models confirmed the presence of four mononuclear complexes for both systems, viz. CuX+, CuX2, CuX3-, and CuX42-. Overall stability constants calculated for the chlorocuprates are β1 = 2.8 × 102, β2 = 1.6 × 104, β3 = 2.3 × 105, and β4 = 4.5 × 105 and for the bromocuprates are β1 = 5.2 × 103, β2 = 3.9 × 105, β3 = 2.0 × 106, and β4 = 2.1 × 106. Individual electronic spectra of all species in methanol are reported for the first time. In this solvent the tetracoordinated chloro complex exhibits a calculated absorption maximum in the near-IR region consistent with a square-planar structure, in contrast to the structure in the solid state, while for the tetrabromocuprate the structure of a flattened tetrahedron is confirmed.
