These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.


Pubmed for Handhelds

PUBMED FOR HANDHELDS

Search MEDLINE/PubMed

  • Title: Synthesis and reactivity of a C3-symmetric trinuclear zinc(II) hydroxide catalyst efficient at phosphate diester transesterification.
    Author: Mitra R, Peters MW, Scott MJ.
    Journal: Dalton Trans; 2007 Sep 21; (35):3924-35. PubMed ID: 17893790.
    Abstract:
    Inspired by trinuclear Zn(II) sites in enzymatic systems, a ligand system containing three preorganized (2-pyridyl)methyl piperazine moieties anchored onto a rigid C3-symmetric triphenoxymethane platform has been developed for preorganizing three zinc ions into an environment conducive to intramolecular interaction. Zinc(II) binding by this ligand has been analyzed by means of potentiometric measurements in 50% (v/v) CH3CN-H2O solutions. Subsequently a C3-symmetric trinuclear Zn(II) hydroxide complex of the C3-symmetric ligand was synthesized and fully characterized using NMR spectroscopy and X-ray crystallography. This complex induces a 16,900-fold rate enhancement in the catalytic cyclization of the RNA model substrate, 2-hydroxypropyl-p-nitrophenyl phosphate (HPNP, pH 6.7, 25 degrees C) over the uncatalyzed reaction with multiple catalyst turnovers. The observed differences in the pH-rate profile can be attributed to the varying concentration of various trinuclear zinc species. The trinuclear Zn(II) catalyst exhibits a higher hydrolytic activity compared to its mononuclear analogue. The reactivity and structural features of this trinuclear Zn(II) complex will be discussed.
    [Abstract] [Full Text] [Related] [New Search]