Metal–Organic Frameworks with Phosphotungstate Incorporated for Hydrolytic Cleavage of a DNA-Model Phosphodiester

Five phosphotungstate-incorporated metal–organic frameworks

{[Eu₄(dpdo)₉(H₂O)₁₆PW₁₂O₄₀]}(PW₁₂O₄₀)₂·(dpdo)₃·Cl₃ (1); {ZnNa₂(μ-

OH)(dpdo)₄(H₂O)₄[PW₁₂O₄₀]}·3H₂O (2); {Zn₃(dpdo)₇}[PW₁₂O₄₀]₂·3H₂O (3); and [Ln₂H(μ-O)₂(dpdo)₄(H₂O)₂][PW₁₂O₄₀]·3H₂O (Ln = Ho for 4 and Yb for5) (dpdo = 4,4′-bipyridine-N,N′-dioxide) have been synthesized through a one-step hydrothermal reaction and characterized by elemental analyses, infrared (IR) spectroscopy, photoluminescence, and single-crystal X-ray diffraction (XRD). The structural analyses indicate that 1–5 display diversity structure from one-dimensional (1D) to three-dimensional (3D) series of hybrids. Kinetic experiments for the hydrolytic cleavage of DNA-model phosphodiester BNPP (bis(p-nitrophenyl)phosphate) were followed spectrophotometrically for the absorbance increase at 400 nm in EPPS (4-(2-hydroxyethyl)piperazine-1-propane sulfonic acid) buffer solution, because of the formation of p-nitrophenoxide with 1–5 under conditions of pH 4.0 and 50 °C. Ultraviolet (UV) spectroscopy indicate that the cleavage of the phosphodiester bond proceeds with the pseudo-first-order rate constant in the range of 10^–7–10^–6 s^–1, giving an inorganic phosphate and p-nitrophenol as the final products of hydrolysis. The results demonstrate that 1–5 have good catalytic activity and reusability for hydrolytic cleavage of BNPP.

Qiuxia Han (et al.). Metal–Organic Frameworks with Phosphotungstate Incorporated for Hydrolytic Cleavage of a DNA-Model Phosphodieste. American Chemical Society. Apr 1, 2012. http://pubs.acs.org/doi/full/10.1021/ic202685e