Conformational isomers of cis-chloro(nitrosyl)(1,4,7,10-tetraazacyclododecene)ruthenium(II), cis-[RuIICl(imcyclen)(NO+)]2+. Oxidation of the coordinated 1,4,7,10-tetraazacyclododecane (cyclen) ligand

Ferreira, Kleber Queiroz; Santos, Flávia Leite Souza; Rocha, Zildete; Guaratini, Thais; Silva, Roberto Santana da; Tfouni, Elia

doi:10.1016/j.inoche.2003.10.017

Cited by 15 publications

(31 citation statements)

References 43 publications

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“…For reasons of stability and symmetry, only the configurational isomers trans-III and trans-I were considered in this study. Although only ruthenium cyclen (12aneN4 or 1,4,7,10-tetraazacyclododecane) complexes with a cis configuration are known, 38,67,68 cyclen derivatives 6-9 were also considered in the same configuration as cyclam and its derivatives 2-5 ( Fig. 2) for comparison.…”

Section: Introductionmentioning

confidence: 99%

The nature of Ru–NO bonds in ruthenium tetraazamacrocycle nitrosyl complexes—a computational study

et al. 2012

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2012The nature of Ru-NO bonds in ruthenium tetraazamacrocycle nitrosyl complexes-a computational study DALTON TRANSACTIONS, CAMBRIDGE, v. 41, n. 24, Ruthenium complexes including nitrosyl or nitrite complexes are particularly interesting because they can not only scavenge but also release nitric oxide in a controlled manner, regulating the NO-level in vivo.The judicious choice of ligands attached to the [RuNO] core has been shown to be a suitable strategy to modulate NO reactivity in these complexes. In order to understand the influence of different equatorial ligands on the electronic structure of the Ru-NO chemical bonding, and thus on the reactivity of the coordinated NO, we propose an investigation of the nature of the Ru-NO chemical bond by means of energy decomposition analysis (EDA), considering tetraamine and tetraazamacrocycles as equatorial ligands, prior to and after the reduction of the {RuNO} 6 moiety by one electron. This investigation provides a deep insight into the Ru-NO bonding situation, which is fundamental in designing new ruthenium nitrosyl complexes with potential biological applications.

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Section: Introductionmentioning

confidence: 99%

The nature of Ru–NO bonds in ruthenium tetraazamacrocycle nitrosyl complexes—a computational study

et al. 2012

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“…Among the NO donors, ruthenium nitrosyl complexes are particularly attractive because they are stable, can be either water soluble or not, deliver NO at different rates upon activation by reduction at biologically accessible potentials and/or by light irradiation, in either solution or matrices. [14][15][16][17][18]34,[40][41][42][43][44][45][46][47][48][49] These properties can be tuned by the adequate choice of ligands. 14,18 It should be pointed out that interesting biological activities for several of these complexes have already been reported.…”

Section: Introductionmentioning

confidence: 99%

Chemical and photochemical properties of a ruthenium nitrosyl complex with the N-monosubstituted cyclam 1-(3-Propylammonium)-1,4,8,11-tetraazacyclotetradecane

Ferreira¹,

Tfouni²

2010

J. Braz. Chem. Soc.

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O complexo aminofuncionalizado trans-[Ru(NO)Cl(1-pramcyH)](PF 6 ) 3 (1-pramcyH = 1-(3-propilamônio)-1,4,8,11-tetraazaciclotetradecano) foi sintetizado através da reação do trans-[RuCl(tfms)(1-pramcyH)](tfms) 2 (tfms = trifluorometanossulfonato) com óxido nítrico (NO) em solução aquosa ácida. O complexo foi caracterizado por análise elementar, espectroscópica (UVvis, IV, RMN de 1 H e 13 C) e eletroquímica. Dois valores de pK a (7,0 e 8,2) foram determinados para trans- [Ru(NO) ](PF 6 ) 3 e foram atribuídos a um dos prótons do grupo amina do cyclam e ao propilamônio. A redução do trans- [Ru(NO) ] 3+ leva à saída rápida de cloreto seguida de saída lenta de NO, enquanto a irradiação do complexo em solução aquosa desaerada resulta na labilização fotoquímica do NO. O rendimento quântico para a fotoaquação do NO diminui com o aumento do comprimento de onda de irradiação e com a diminuição do pH, e é observável apenas a l irr < 370 nm. O comportamento do trans- [Ru(NO) ] 3+ é semelhante ao do complexo análogo trans- [Ru(NO) Cl(cyclam)] 2+ , porém difere daquele do complexo com carboxipropil como substituinte.The amine-functionalized trans- [Ru(NO) ](PF 6 ) 3 complex (1-pramcyH = 1-(3-propylammonium)-1,4,8,11-tetraazacyclotetradecane) was synthesized from trans- [RuCl(tfms) (1-pramcyH)](tfms) 2 (tfms = trifluoromethanesulfonate) in acidic aqueous solution in the presence of nitric oxide (NO). The complex was characterized by elemental, spectroscopic (UV-Vis, IR, 1 H and 13 C NMR) and electrochemical analyses. Two pK a values (7.0 and 8.2) were estimated for trans- [Ru(NO) ](PF 6 ) 3 and were assigned to one of the cyclam nitrogen protons and to the protonated aminopropyl group. Reduction of trans- [Ru(NO) ] 3+ results in rapid loss of chloride followed by slower loss of NO, while irradiation of the complex in aqueous deaerated conditions suggests photochemical labilization of NO. The quantum yields for NO photoaquation decrease as the irradiation wavelength increases, being noticeable only at l irr < 370 nm, and increase as pH increases. The behavior of trans- [Ru(NO) ] 3+ , which contains an aminopropyl substituted cyclam, parallels that reported for the analogous complex with the unsubstituted ligand, but differs from that described for the complex in which carboxypropyl is the substituent. Keywords: nitrosyl, ruthenium, nitric oxide donor, substituted cylam, mono-N-functionalized cyclam IntroductionThe discovery of the participation of nitric oxide (NO) in a wide range of physiological processes and pathologies 1 has launched investigations on NO donors, including metal nitrosyl complexes in solution or immobilized in matrices, aiming at the understanding of both fundamental aspects and biological activity for potential applications. Among the NO donors, ruthenium nitrosyl complexes are particularly attractive because they are stable, can be either water soluble or not, deliver NO at different rates upon activation by reduction at biologically accessible Chemical and Photochemical Properties of a Ruthenium Nitrosyl...

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“…One consists in electrochemical oxidation in basic medium of trans-[Ru(OH 2 ) 2 (CMe 6 -cyclam)] + forming [Ru(OH 2 ) 2 ([14]-diene)] 3+ [90]. The other is a consequence of an oxidative dehydrogenation of cis-[RuCl 2 (cyclen)] + in basic medium using air which converts amine to imine forming cis-[RuCl(OH)(imcyclen)] + [36]. In contrast to the former, it is not a controlled method, and several Ru(II) complexes with ligands such as bpy, phen, and 4-NCpy, cis-[Ru II L 1 L 2 (imcyclen)] n+ (L 1 = L 2 = bpy, phen, 4-NCpy; L 1 = Cl − , OH − , H 2 O and L 2 = NO + ) were obtained using it [35,36].…”

Section: Unsaturated Tetraazamacrocyclic Complexesmentioning

confidence: 99%

“…The forms adopted by the complex were determined by 1 H and 13 C NMR spectra using several techniques. The trans-[NiL 1 L 2 (cyclam)] 2+ was obtained as a mixture of the five conformational isomers, while the cis-[ML 1 L 2 (cyclen)] q+ (M = Co, Ru; L = Cl − , NO, bpy, phen, 4-NCpy) complexes were obtained as a mixture of anti-syn, syn-syn conformational isomers [35,36]. A solvatochromic effect is observed in the 1 H NMR spectra of trans-[RuCl(4-acpy)(cyclam)] + , as can be seen by the shift of the cyclam NH hydrogens from 4.54 and 4.09 ppm in dmso-d 6 to 4.50 and 3.79 ppm in acetone-d 6 .…”

Section: Epr Infrared and Nuclear Magnetic Resonance Spectramentioning

confidence: 99%

“…In aqueous solution, [Ru II L 1 L 2 (cyclen)] q+ (L 1 = NO, L 2 = Cl; L 1 = L 2 = bpy, phen or 4-NCpyH + ) undergoes macrocycle oxidative dehydrogenation [35,36], and stereoisomerization of the hydrogen in N H groups of cyclen in aqueous and organic media was observed. An uncommon example is the isomerization in the synthesis of trans-[Ru(NO)(OH)(cyclam)](ClO 4 ) 2 using cis-[RuCl 2 (cyclam)]Cl as starting material [37].…”

Section: Introductionmentioning

confidence: 99%

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The versatile ruthenium(II/III) tetraazamacrocycle complexes and their nitrosyl derivatives

Doro

Ferreira

Rocha

et al. 2016

Coordination Chemistry Reviews

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Conformational isomers of cis-chloro(nitrosyl)(1,4,7,10-tetraazacyclododecene)ruthenium(II), cis-[RuIICl(imcyclen)(NO+)]2+. Oxidation of the coordinated 1,4,7,10-tetraazacyclododecane (cyclen) ligand

Cited by 15 publications

References 43 publications

The nature of Ru–NO bonds in ruthenium tetraazamacrocycle nitrosyl complexes—a computational study

The nature of Ru–NO bonds in ruthenium tetraazamacrocycle nitrosyl complexes—a computational study

Chemical and photochemical properties of a ruthenium nitrosyl complex with the N-monosubstituted cyclam 1-(3-Propylammonium)-1,4,8,11-tetraazacyclotetradecane

The versatile ruthenium(II/III) tetraazamacrocycle complexes and their nitrosyl derivatives

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