Polynuclear paddle-wheel copper(II) propionate with di-2-pyridylamine or 1,10-phenanthroline: Preparation, characterization and X-ray structure

Abstract

The synthesis, spectroscopic, magnetic and structural characterization of two new polynuclear copper(II) propionate are described. Both compounds exhibit the typical paddle-wheel type structure. The complex [Cu 4(dpyam) 2(OCOC 2H 5) 2(μ-O 2CC 2H 5) 6(H 2O) 2][Cu 2(μ- O 2CC 2H 5) 4(H 2O) 2] · (DMF) 2 1; where dpyam = di-2-pyridylamine, the “outer” Cu ions, with a CuN 2O 2O′ chromophore, have an intermediate five-coordinate geometry. The “inner” Cu ions, with a CuO 4O′ chromophore, have a square pyramidal geometry. The two Cu(II) ions in the inner unit are bridged by four syn, syn-η 1:η 1:μ propionates, showing the paddle-wheel cage type. The “outer” and “inner” linked by propionate bridges showing syn, anti-η 1:η 1:μ coordination mode. The 1D structure of complex [Cu 6(phen) 2(H 2O) 2(μ-O 2CC 2H 5) 12] n [Cu 2(μ-O 2CC 2H 5) 4(H 2O) 2] 2 n · (H 2O) 0.5 n 2; where phen = 1,10-phenanthroline, consists of zig-zag chains of mononuclear Cu(μ-O 2CC 2H 5) 2(H 2O)(phen) repeating units running along the b-axis, which are connected along the unit cell diagonal via Cu 2(μ-O 2CC 2H 5) 4 paddle-wheel dinuclear units. Within mononuclear and dinuclear units, the Cu(II) ions have a square pyramidal geometry. However, the outer sphere of both compounds consists of the Cu 2(μ-O 2CC 2H 5) 4(H 2O) 2 paddle-wheel molecule in which Cu(II) ions involve a square pyramidal geometry.