Crystal structure and molecular stereochemistry of polymeric Cu ₂(DMP)₄(DMSO) as a platform for phosphate diester binding

چکیده مقاله

Treatment of a solution of CuCl₂ in dimethyl phosphate (DMP) in an inert solvent under nitrogen atmosphere resulted in a light blue fluorescence powder. Slow evaporation of H₂O-DMSO solution of this powder led to the formation of blue-sky crystals of a new polymeric Cu(II) complex, with a unit cell composed of Cu₂(DMP)₄(DMSO), (1). The crystal and molecular structure of the complex was established crystallographically. Compound (1) crystallizes in the monoclinic space group P2₁/n with a = 12.8920(11)Å, b = 13.1966(11)Å, c = 14.7926(13)Å, α = 90°, β= 98.943(2)°, γ = 90° and Z = 4. A square pyramidal environment for the metal center is established by coordination of oxygen atoms of four bridging DMP ligands in the basal positions and a tri-centered oxygen atom of DMSO in the apical disposition. The sixth position is also affected by a weak interaction with the sulfur atom of DMSO. The phosphorous atom in the bridging DMP is arranged in a deformed tetrahedron with gg conformation for methyl esters with C_2v symmetry. Accordingly, the angles of methoxy substituents are unexpectedly smaller than the bridging oxygens, and synchronous z-in and z-out distortions are suggested for DMP anion. The oxygen atom of SOCuCu' fragment derived from DMSO, functions as a tri-centered nuclei lie almost in a trigonal triangle environment. This study helps provide further insights into the binding nature of phosphate esters to the active sites of enzymes, which catalyze phosphoryl transfer reactions. © 2006 WILEY-VCH Verlag GmbH & Co. KGaA.