A Controlled NO-Releasing Compound: Synthesis, Molecular Structure, Spectroscopy, Electrochemistry, and Chemical Reactivity of R,R,S,S-trans-[RuCl(NO)(cyclam)]2
详细信息 查看全文
- 作者：D. R. Lang ; J. A. Davis ; L. G. F. Lopes ; A. A. Ferro ; L. C. G. Vasconcellos ; D. W. Franco ; E. Tfouni ; A. Wieraszko ; and M. J. Clarke
- 刊名：Inorganic Chemistry
- 出版年：2000
- 出版时间：May 29, 2000
- 年：2000
- 卷：39
- 期：11
- 页码：2294 - 2300
- 全文大小：105K
- 年卷期：v.39,no.11(May 29, 2000)
- ISSN：1520-510X
文摘
The synthesis of trans-[RuCl(NO)(cyclam)]2+ (cyclam = 1,4,8,11-tetraazacyclotetradecane) can be accomplishedby either the addition of cyclam to K2[RuCl5NO] or by the addition of NO to trans-[RuCl(CF3SO3)(cyclam)](CF3SO3). Crystals of trans-[RuCl(NO)(cyclam)](ClO4)2 form in the monoclinic space group P21/c, with unit cellparameters of a = 7.66500(2) Å, b = 24.7244(1) Å, c = 16.2871(2) Å, 
= 95.2550(10)
, and Z = 4. One of thetwo independent molecules in the unit cell lies disordered on a center of symmetry. For the ion in the generalposition, the Ru-N and N-O bond distances and the [Ru-N-O]3+ bond angle are 1.747(4) Å, 1.128(5) Å,178.0(4), respectively. In both ions, cyclam adopts the (R,R,S,S) configuration, which is also consistent with 2DCOSY 1H NMR studies in aqueous solution. Reduction (E = -0.1 V) results in the rapid loss of Cl- by first-order kinetics with k = 1.5 s-1 and the slower loss of NO (k = 6.10 × 10-4 s-1, 
H
= 15.3 kcal mol-1, S= -21.8 cal mol-1 K-1). The slow release of NO following reduction causes trans-[RuCl(NO)(cyclam)]2+ to bea promising controlled-release NO prodrug for vasodilation and other purposes. Unlike the related complex trans-[Ru(NO)(NH3)4(P(OEt)3)](PF6)2, trans-[RuCl(NO)(cyclam)]Cl2 is inactive in modulating evoked potentials recordedfrom mice hippocampal slices probably because of the slower dissociation of NO following reduction.
= 95.2550(10), and Z = 4. One of thetwo independent molecules in the unit cell lies disordered on a center of symmetry. For the ion in the generalposition, the Ru-N and N-O bond distances and the [Ru-N-O]3+ bond angle are 1.747(4) Å, 1.128(5) Å,178.0(4), respectively. In both ions, cyclam adopts the (R,R,S,S) configuration, which is also consistent with 2DCOSY 1H NMR studies in aqueous solution. Reduction (E = -0.1 V) results in the rapid loss of Cl- by first-order kinetics with k = 1.5 s-1 and the slower loss of NO (k = 6.10 × 10-4 s-1, H = 15.3 kcal mol-1, S= -21.8 cal mol-1 K-1). The slow release of NO following reduction causes trans-[RuCl(NO)(cyclam)]2+ to bea promising controlled-release NO prodrug for vasodilation and other purposes. Unlike the related complex trans-[Ru(NO)(NH3)4(P(OEt)3)](PF6)2, trans-[RuCl(NO)(cyclam)]Cl2 is inactive in modulating evoked potentials recordedfrom mice hippocampal slices probably because of the slower dissociation of NO following reduction.