Cis– trans isomerization in the syntheses of ruthenium cyclam complexes with nitric oxide

• Published in: Inorganic chemistry communications 2012, Vol.15, p.93-96
• Main Authors: Vidal, Robson da Silva, Doro, Fábio Gorzoni, Ferreira, Kleber Queiroz, da Rocha, Zênis Novais, Castellano, Eduardo Ernesto, Nikolaou, Sofia, Tfouni, Elia
• Format: Article
• Language: English
• Subjects: Cis– trans isomerization; Cyclam; Nitric oxide; Nitrite; Nitrosyl; Ruthenium
• ISSN: 1387-7003; 1879-0259
• DOI: 10.1016/j.inoche.2011.09.046

The cis to trans isomerizations during the syntheses of trans-[Ru(NO)(OH)(cyclam)](PF 6) 2, from cis-[RuCl 2(cyclam)]Cl, and [Ru(NO)Cl(cyclam)] (PF 6) 2, from cis-[RuCl 2(dmso) 4], are reported. The novel trans-[Ru(NO)(OH)(cyclam)](PF 6) 2 complex was characterized by X-ray crystallography and vibrational infrared and nuclear magnetic resonance spectroscopies. The Ru–N–O bond angle (176.75º) and ν(NO) (1835 cm − 1 ) suggest a nitrosonium character for this hydroxo complex. The crystal and molecular structure of trans-[Ru(NO)Cl(cyclam)](ClO 4) 2·2 H 2O is also reported. Results presented here support the cis– trans isomerization observed for the first time with ruthenium cyclam complexes. Cis– trans isomerization in the syntheses of [Ru(NO)L(cyclam)] from cis-[RuCl 2(cyclam)]Cl after reduction and followed by addition of nitrite [Display omitted] ► Cis– trans isomerization in the syntheses of [Ru(NO)L(cyclam)] from cis complexes. ► Trans–ruthenium nitrosyl complexes with cyclam ligand synthesized from cis analogues. ► Cis– trans isomerization in the syntheses of [Ru(NO)L(cyclam)] upon addition of nitrite. ► Novel trans-[Ru(NO)(OH)(cyclam)](PF 6) 2 complex obtained from cis-[RuCl 2(cyclam)]Cl. ► Trans-[Ru(NO)Cl(cyclam)](ClO 4) 2 obtained from cis-[RuCl 2(dmso) 4]. ► Cis– trans isomerizations are supported by X-ray crystallography and other techniques.