Transesterification of RNA model induced by novel dinuclear copper (II) complexes with bis-tridentate imidazole derivatives.

Abstract

Two novel bis-tridentate imidazole derivatives were conveniently synthesized using a 'one-pot' method. Their dinuclear (Cu2L1Cl4, Cu2L2Cl4) and mononuclear (CuL1Cl2, CuL2Cl2∙H2O) copper (II) complexes were synthesized to comparably evaluate their reactivities in the hydrolytic cleavage of 2-hydroxypropyl p-nitrophenyl phosphate (HPNP) as a classic RNA model. Single crystals of Cu2L1Cl4 and Cu2L2Cl4 indicate that both of them are centrosymmetric, and each central copper ion is penta-coordinated. Regarding the transesterification of HPNP, both of dinuclear ones exhibited excess one order of magnitude rate enhancement in contrast with auto-hydrolysis reaction. Under comparable conditions, dinuclear complexes displayed no more than twofold increase in activity over their mononuclear analogues, which verifies the lack of binuclear cooperation effect due to long Cu-to-Cu space.