title: Design of an NO photoinduced releaser xerogel based on the controlled nitric oxide donor trans-[Ru(NO)Cl(cyclam)](PF6)2 (cyclam=1,4,8,11-tetraazacyclotetradecane).
abstract: The immobilization and properties of the nitric oxide donor trans-[Ru(NO)Cl(cyclam)](PF(6))(2), RuNO, entrapped in a silica matrix by the sol-gel process is reported herein. The entrapped nitrosyl complex was characterized by spectroscopic (UV-vis, infrared (IR), X-ray photoelectron, and (13)C and (29)Si MAS NMR) and electrochemical techniques. The entrapped species exhibit one characteristic absorption band in the UV-vis region of the electronic spectrum at 354 nm and one IR nu(NO) stretching band at 1865 cm(-1), as does the RuNO species in aqueous solution. Our results show that trans-[Ru(NO)Cl(cyclam)](PF(6))(2) can be entrapped in a SiO(2) matrix with preservation of the molecular structure. However, in a SiO(2)/SiNH(2) matrix, the complex undergoes a nucleophilic attack by the amine group at the nitrosonium. Irradiation of the complex, entrapped in the SiO(2) matrix, with light of 334 nm, resulted in NO release. The material was regenerated to its initial nitrosyl form by reaction with nitric oxide.
authors.affiliation: Departamento de Química, Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, Universidade de São Paulo, Av. dos Bandeirantes 3900, 14040-901 Ribeirão Preto, SP, Brazil.
authors.forename: Kleber Queiroz
authors.initials: KQ
authors.lastname: Ferreira
authors.forename: José F
authors.initials: JF
authors.lastname: Schneider
authors.forename: Pedro A P
authors.initials: PA
authors.lastname: Nascente
authors.forename: Ubirajara Pereira
authors.initials: UP
authors.lastname: Rodrigues-Filho
authors.forename: Elia
authors.initials: E
authors.lastname: Tfouni
mesh_terms: D000588:Amines / Q000737:chemistry; D002251:Carbon Tetrachloride / Q000737:chemistry; D015195:Drug Design; D004563:Electrochemistry / Q000379:methods; D005782:Gels / Q000737:chemistry*; D008027:Light; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D008855:Microscopy, Electron, Scanning; D009569:Nitric Oxide / Q000737:chemistry*; D020030:Nitric Oxide Donors / Q000737:chemistry / Q000494:pharmacology*; D009584:Nitrogen / Q000737:chemistry; D009942:Organometallic Compounds / Q000737:chemistry*; D012428:Ruthenium / Q000737:chemistry; D012822:Silicon Dioxide / Q000737:chemistry*; D013055:Spectrophotometry, Infrared / Q000379:methods*; D014965:X-Rays
chemical_list: C471988:(RuCl(NO)(cyclam))2; D000588:Amines; D005782:Gels; D020030:Nitric Oxide Donors; D009942:Organometallic Compounds; D009569:Nitric Oxide; D012822:Silicon Dioxide; D012428:Ruthenium; D002251:Carbon Tetrachloride; D009584:Nitrogen