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Different Isomers Of [RuII(NO+)(hedta)(H2O)] Prepared From Ru(NO)Cl3 Via Chelation By Hedta3− Than By NO2 − Addition To [Ru(H2O)(hedta)]−

Y. Chen, R. E. Shepherd
Published 2003 · Chemistry

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Abstract NO 2  − substitution on [Ru II (H 2 O)(hedta)] − , followed by acidification, forms almost exclusively the cis -equatorial [Ru II (NO + )(hedta)] isomer ( 1a ) ( υ NO =1846 cm −1 ). However, the reaction of a pre-formed ruthenium nitrosyl complex, Ru(NO)Cl 3 (H 2 O) 2 , with hedta 3− (pH∼3.0, 1.5 h, ∼80 °C) produced two different products ( 2a , 2b ). Complexes 2a and 2b , [Ru(NO)(hedta)X], have structures that are derived from the energetically much less favorable cis -polar [Ru II (NO + )(hedta)] isomer by a displacement of one glycinato donor by X=H 2 O or Cl − , either trans ( 2b ) or cis ( 2a ) to NO + . Both isomer products ( 2a , 2b ) have υ NO =1882 cm −1 , indicative of rather similar oxygen donors trans to NO + . Complex 2a (66%) has the NO + group cis to in-plane X=H 2 O or Cl − and the two N donors of hedta 3− . Complex 2a also has one axial glycinato chelate from the N -hydroxyethyl nitrogen ( R ), and one in-plane glycinato chelate from the second N donor ( R ). The ( R , R ) placement of the pendant ethyl and glycinato units are in an ‘up,down’ arrangement for 2a , minimizing repulsions for the pendant groups. Complex 2b (33%) has two in-plane glycinato chelate rings and the two in-plane en-type N donors, as for cis -polar [Ru(NO)(hedta)], but with the axial glycinato group of 2a moved to the in-plane location, and retaining the ( R , R ) ‘up,down’ chiralities. The coordination assignments for the glycinato rings from 1 H and 13 C NMR data are supported by MMFF94 calculations wherein 2a ( R , R ) (‘up,down’) is more stable than ( R , S ) (‘up,up’) by approximately 36 kcal mol −1 . The calculations are sensitive to the central angles with the Ru center, which were constrained to 90° angles in the calculations. For lesser isomer 2b , it was determined that the stability of the placement of pendant groups follows the order ( R , R ) (‘up,down’)>( S , R ) (‘down,down’)∼( S , S ) (‘down,up’) > ( R , S ) (‘up,up’). The Ru II (NO + )/Ru II (NO − ) reduction potential of 2a and 2b is −0.12 V versus NHE, similar to −0.10 V for 1a . Since the [Ru(NO)(hedta)] coordination is most favored for a cis -equatorial complex than complexes derived from cis -polar, the addition of the hedta 3− ligand forms 2a and 2b under kinetic control wherein substitution of the first and second N donors occur cis to the NO + group.
This paper references
Coordination and organometallic chemistry of metal-NO complexes.
Trevor W Hayton (2002)
Coordination of Ru(NO)Cl3 to the tripeptides glyglygly and glyglyhis: N-terminal amine–amide and C-terminal imidazole–amide functionalities in bidentate chelation
J. Slocik (2000)
Nitrato and nitro complexes of nitrosylruthenium
J. M. Fletcher (1955)
A controlled NO-releasing compound: synthesis, molecular structure, spectroscopy, electrochemistry, and chemical reactivity of R,R,S,S-trans-[RuCl(NO)(cyclam)]2+(1,4,8,11-tetraazacyclotetradecane).
D. R. Lang (2000)
Preparation and Characterization of Ethylenediaminetrihalogenonitrosylruthenium(III) Complexes
H. Tomizawa (1993)
Developing Carrier Complexes for “Caged NO”: RuCl3(NO)(H2O)2 Complexes of Dipyridylamine, (dpaH), N,N,N'N'-Tetrakis (2-Pyridyl) Adipamide, (tpada), and (2-Pyridylmethyl) Iminodiacetate, (pida2-)
J. Slocik (2000)
Toxicology and pharmacology of some ruthenium compounds: Vascular smooth muscle relaxation by nitrosyl derivatives of ruthenium and iridium.
H. Kruszyna (1980)
Coordination of RuCl3(NO)(H2O)2 by imidazole, histidine and iminodiacetate ligands: a study of complexation of 'Caged NO' by simple bio-cellular donors
J. Slocik (2001)
[Ru2II(ttha)(H2O)2]2− is a rapid No scavenger (ttha6− = triethylenetetraminehexaacetate)
Y. Chen (1997)
Nitric oxide donors: chemical activities and biological applications.
P. Wang (2002)
Kinetics of nitric oxide scavenging by ruthenium(iii)polyaminocarboxylates: novel therapeutic agents for septic shock
N. Davies (1997)
Electrospray mass spectrometry of trans-[Ru(NO)Cl(dpaH)2]2+ (dpaH=2,2′-dipyridylamine) and ‘caged NO’, [RuCl3(NO)(H2O)2]: loss of HCl and NO from positive ions versus NO and Cl from negative ions
J. Slocik (2001)
Synthesis and characterization of meso-[Ru(NO)Cl(dioxocyclam)] and the 1H NMR comparison with [MII(dioxocyclam)] complexes (MII=NiII and PdII) (dioxocyclam=1,4,8,11-tetraazacyclotetradecane-5,7-dione)
J. Slocik (2001)
Potency and kinetics of nitric oxide‐mediated vascular smooth muscle relaxation determined with flash photolysis of ruthenium nitrosyl chlorides
T. D. Carter (1997)
Vasodilator effects of organotransition-metal nitrosyl complexes, novel nitric oxide donors.
Y. X. Wang (2000)
Photolabile donors of nitric oxide: ruthenium nitrosyl chlorides as caged nitric oxide.
N. Bettache (1996)
The influence of NO-containing ruthenium complexes on mouse hippocampal evoked potentials in vitro.
A. Wieraszko (2001)
15N NMR and Electrochemical Studies of [Ru(II)(hedta)](-) Complexes of NO, NO(+), NO(2)(-), and NO(-).
Y. Chen (1999)
Photoreactivity of the Ruthenium Nitrosyl Complex, Ru(salen)(Cl)(NO). Solvent Effects on the Back Reaction of NO with the Lewis Acid RuIII(salen)(Cl)1
Carmen F. Works and (2000)
Ruthenium complexes as nitric oxide scavengers: a potential therapeutic approach to nitric oxide‐mediated diseases
S. Fricker (1997)
Hypotensive properties and acute toxicity of trans-[Ru(NH(3))(4)P(OEt)(3)(NO)](PF(6))(3), a new nitric oxide donor.
A. S. Torsoni (2002)
Mechanistic studies on AMD6221: a ruthenium-based nitric oxide scavenger.
R. Mosi (2002)

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