期刊
INORGANIC CHEMISTRY
卷 53, 期 23, 页码 12459-12468出版社
AMER CHEMICAL SOC
DOI: 10.1021/ic5018714
关键词
-
资金
- U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences [DE-AC02-76SF00515]
- DOE Office of Biological and Environmental Research
- National Institutes of Health, National Institute of General Medical Sciences [P41GM103393]
- National Science and Engineering Research Council of Canada (NSERC)
- Canadian Foundation for Innovation (CFI)
- Province of Alberta (Department of Innovation and Science)
- University of Calgary
- NATIONAL INSTITUTE OF GENERAL MEDICAL SCIENCES [P41GM103393] Funding Source: NIH RePORTER
A spectroscopic investigation of the complexes formed between the Pb(II) ion and d-penicillamine (H(2)Pen), a chelating agent used in the treatment of lead poisoning, was carried out on two sets of alkaline aqueous solutions with C-Pb(II) approximate to 10 and 100 mM, varying the H2Pen/Pb(II) molar ratio (2.0, 3.0, 4.0, 10.0). Ultraviolet-visible (UV-vis) spectra of the 10 mM Pb(II) solutions consistently showed an absorption peak at 298 nm for S(-) ? Pb(II) ligand-to-metal charge-transfer. The downfield (13)C NMR chemical shift for the penicillamine COO(-) group confirmed Pb(II) coordination. The (207)Pb NMR chemical shifts were confined to a narrow range between 1806 ppm and 1873 ppm for all Pb(II)-penicillamine solutions, indicating only small variations in the speciation, even in large penicillamine excess. Those chemical shifts are considerably deshielded, relative to the solid-state (207)Pb NMR isotropic chemical shift of 909 ppm obtained for crystalline penicillaminatolead(II) with Pb(S,N,O-Pen) coordination. The Pb LIII-edge extended X-ray absorption fine structure (EXAFS) spectra obtained for these solutions were well-modeled with two Pb-S and two Pb-(N/O) bonds with mean distances 2.64 +/- 0.04 angstrom and 2.45 +/- 0.04 angstrom, respectively. The combined spectroscopic results, reporting delta Pb-207) 1870 ppm and ?max 298 nm for a Pb(II)S2NO site, are consistent with a dominating 1:2 lead(II):penicillamine complex with [Pb(S,N,O-Pen)(S-HnPen)](2-n) (n = 0-1) coordination in alkaline solutions, and provide useful structural information on how penicillamine can function as an antidote against lead toxicity in vivo.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据