IFEG   20353
INSTITUTO DE FISICA ENRIQUE GAVIOLA
Unidad Ejecutora - UE
artículos
Título:
1H-NMR Relaxation Study of a Magnetic Ionic Liquid as a Potential Contrast Agent
Autor/es:
C. DANIEL; F. VACA CHAVEZ; C. PORTUGAL; JOÃO CRESPO; P. SEBASTIAO
Revista:
JOURNAL OF PHYSICAL CHEMISTRY B - (Print)
Editorial:
AMER CHEMICAL SOC
Referencias:
Lugar: Washington; Año: 2015
ISSN:
1520-6106
Resumen:
A Proton Nuclear Magnetic Relaxation dispersion 1HNMRD study of the moleculardynamics in mixtures of magnetic ionic liquid [P66614][FeCl4] with [P66614][Cl] ionic liq-uid and mixtures of [P66614][FeCl4] with Dimethyl sulfoxide (DMSO) is presented. Theproton spin lattice relaxation rate, R1, was measured in the frequency range of 8kHz-300MHz. The viscosity of the binary mixtures was measured as a function of an appliedmagnetic eld, B, in the range of 0 - 2T. In the case of DMSO/[P66614][FeCl4] the vis-cosity was found to be independent from the magnetic eld while in the case of the[P66614][Cl]/[P66614][FeCl4] system viscosity decreased with the increase of the magneticeld strength. The spin lattice relaxation results were analyzed for all systems takinginto account the relaxation mechanisms associated to the molecular motions with cor-relation times in a range between 10􀀀11 􀀀 10􀀀7s, usually observed by NMRD, and theparamagnetic relaxation contributions associated with the presence of the magneticions in the systems. In the case of DMSO/[P66614][FeCl4] system the R1 dispersionshows the relaxation enhancement due to the presence of the magnetic ions, similarto that reported for contrast agents. For the [P66614][Cl]/[P66614][FeCl4] system, theR1 dispersion presents a much larger paramagnetic relaxation contribution, in com-parison with that observed for the DMSO/[P66614][FeCl4]mixtures, but dierent fromthat reported for other magnetic ionic liquid system. In the [P66614][Cl]/[P66614][FeCl4]system the relaxation enhancement associated to the paramagnetic ions is clearly notproportional to the concentration of magnetic ions, in contrast with what is observedfor the DMSO/[P66614][FeCl4]system