Colombia
Colombia
Los complejos sintetizados [RuCl2(2,6-dmpz)2(PPh3)2] y [RuCl2(CO)(N-het)(PPh3)2], (donde N-het son 2,6-dimetilpirazina (2,6-dmpz), Imidazol (Imz) y pirazina (pz)) PPh3 = trifenilfosfina, se sintetizaron a partir de RuCl2(PPh3)3 y un ligando N-heterocíclico. Estos complejos se caracterizaron por técnicas espectroscópicas. Para el complejo [RuCl2(2,6-dmpz)2(PPh3)2] el espectro Ir indica que los cloros se encuentran en posición cis. El espectro electrónico de los complejos presenta intensas bandas de transferencia de carga, asignadas a las transiciones de los orbitales dp llenos del rutenio a los orbitales pp * vacíos de los anillos N-heterocíclicos. Los estudios térmicos de DSC y TGA para los complejos del tipo diclorocarbonil(N-heterocíclico)bis(trifenilfosfina)rutenio(II), donde los N-heterocíclicos son 2,6-dmpz, Imz y pz, indican que la estabilidad térmica de los complejos depende de la nucleofílidad del ligando nitrogenado.
The complexes [RuCl2(2,6-dmpz)2(PPh3)2] and [RuCl2(CO)(PPh3)2(N-het)] (N-het is imidazol (Imz) 2,6-dimethylpyrazine (2,6-dmpz) and pyrazine (pz)) PPh3 = triphenilphosfine), were synthized from RuCl2(PPh3)3 and a N-heterocyclic ligand. The complexes were characterized by spectroscopic techniques. The vibrational spectrum of [RuCl2(2,6-dmpz)2(PPh3)2] indicat that chlorine atoms are in cis position. The spectrum is from 31P-NMR indicated that phosphines are in position trans. The electronic spectra of these complexes exhibited intense bands of charge transfer assigned to the transitions of the occupied dp orbitals of ruthenium to the empty ppi * orbitals of the N-heterocyclic rings. The curve of DSC (Differential Scanning Calorimetryc) indicates that the complexe dichlorobis(2,6-dimethyilpirazine)bis(triphenylphosphine)ruthenium(II) suffers an exothermic phase transition at 231 0C. From the TGA the exothermic phase transition is due to a loss of mass that is characterized as to tha dissociation of one of 2,6-dmpz and a PPh3. The thermal studies of the complexes of the type RuCl2(CO)(PPh3)2(N-het), where N-het is a 2,6-dmpz, Imz and pz, by DSC and TGA indicate that thermal stability of ths complexes depend on the nucleophilicity of the nitrogen ring.
© 2001-2024 Fundación Dialnet · Todos los derechos reservados