INVESTIGADORES
ROMANO rosana mariel
artículos
Título:
Vibrational Spectra, Crystal Structures, Linkage and Rotational Isomerism of FC(O)SCN and FC(O)NCS
Autor/es:
LUIS A. RAMOS; SONIA E. ULIC; ROSANA M. ROMANO; MAURICIO F. ERBEN; CHRISTIAN W. LEHMANN; EDUARD BERNHARDT; HELMUT BECKERS; HELGE WILLNER; CARLOS O. DELLA VéDOVA
Revista:
INORGANIC CHEMISTRY
Editorial:
AMER CHEMICAL SOC
Referencias:
Año: 2010 vol. 49 p. 11142 - 11157
ISSN:
0020-1669
Resumen:
Fluorocarbonyl thio- and isothiocyanate, FC(O)SCN and FC(O)NCS, were fully characterized by IR (gas, Ar and N2(O)SCN and FC(O)NCS, were fully characterized by IR (gas, Ar and N2
matrixes), Raman (liquid and solid), UV (gas), and 13C NMR (liquid) spectroscopy, as well as single-crystal X-ray
diffraction. Their vibrational and conformational properties were analyzed using matrix isolation techniques guided by
quantum chemical calculation at the ab initio [MP2 and CCSD(T)], density functional theory B3LYP, and CBS-QB3
levels of theory. A complete assignment of the fundamental modes of FC(O)SCN was performed. In both the gas and
liquid states, FC(O)SCN and FC(O)NCS were found to exist as two conformers (Cs symmetry), in which the carbonyl
double bond (CdO) adopts a synperiplanar (syn) and an antiperiplanar (anti ) orientation with respect to either the
SCN or NCS group. For FC(O)SCN, the conformational enthalpy difference, ÄH = H(anti ) - H(syn), was
determined by matrix IR experiments to be 0.9(0.2 kcal mol-1. The conformational equilibria were evaluated by fastcooling
gaseous samples highly diluted in argon at different temperatures as cryogenic matrixes. The conformational
properties of both molecules were analyzed in terms of the hyperconjugative electronic effect applying the natural bond
orbital method. The kinetics of the thermal conversion of the high-energy anti into the syn FC(O)NCS conformer was
studied in Ar and N2 matrixes at cryogenic temperatures. The reversed synfanti photoisomerization was observed
using UV-vis light. Rearrangement of FC(O)SCN into FC(O)NCS was observed in the neat liquid and in solution.
Under 193 nm (ArF excimer laser) irradiation, FC(O)NCS isolated in cryogenic Ar matrixes forms FC(O)SCN. At low
temperature, single crystals of the two constitutional isomers were obtained using a miniature zone melting procedure.
According to X-ray diffraction, they exclusively crystallize in their syn forms (Cs symmetry) in the orthorhombic crystal
system.), Raman (liquid and solid), UV (gas), and 13C NMR (liquid) spectroscopy, as well as single-crystal X-ray
diffraction. Their vibrational and conformational properties were analyzed using matrix isolation techniques guided by
quantum chemical calculation at the ab initio [MP2 and CCSD(T)], density functional theory B3LYP, and CBS-QB3
levels of theory. A complete assignment of the fundamental modes of FC(O)SCN was performed. In both the gas and
liquid states, FC(O)SCN and FC(O)NCS were found to exist as two conformers (Cs symmetry), in which the carbonyl
double bond (CdO) adopts a synperiplanar (syn) and an antiperiplanar (anti ) orientation with respect to either the
SCN or NCS group. For FC(O)SCN, the conformational enthalpy difference, ÄH = H(anti ) - H(syn), was
determined by matrix IR experiments to be 0.9(0.2 kcal mol-1. The conformational equilibria were evaluated by fastcooling
gaseous samples highly diluted in argon at different temperatures as cryogenic matrixes. The conformational
properties of both molecules were analyzed in terms of the hyperconjugative electronic effect applying the natural bond
orbital method. The kinetics of the thermal conversion of the high-energy anti into the syn FC(O)NCS conformer was
studied in Ar and N2 matrixes at cryogenic temperatures. The reversed synfanti photoisomerization was observed
using UV-vis light. Rearrangement of FC(O)SCN into FC(O)NCS was observed in the neat liquid and in solution.
Under 193 nm (ArF excimer laser) irradiation, FC(O)NCS isolated in cryogenic Ar matrixes forms FC(O)SCN. At low
temperature, single crystals of the two constitutional isomers were obtained using a miniature zone melting procedure.
According to X-ray diffraction, they exclusively crystallize in their syn forms (Cs symmetry) in the orthorhombic crystal
system.[MP2 and CCSD(T)], density functional theory B3LYP, and CBS-QB3
levels of theory. A complete assignment of the fundamental modes of FC(O)SCN was performed. In both the gas and
liquid states, FC(O)SCN and FC(O)NCS were found to exist as two conformers (Cs symmetry), in which the carbonyl
double bond (CdO) adopts a synperiplanar (syn) and an antiperiplanar (anti ) orientation with respect to either the
SCN or NCS group. For FC(O)SCN, the conformational enthalpy difference, ÄH = H(anti ) - H(syn), was
determined by matrix IR experiments to be 0.9(0.2 kcal mol-1. The conformational equilibria were evaluated by fastcooling
gaseous samples highly diluted in argon at different temperatures as cryogenic matrixes. The conformational
properties of both molecules were analyzed in terms of the hyperconjugative electronic effect applying the natural bond
orbital method. The kinetics of the thermal conversion of the high-energy anti into the syn FC(O)NCS conformer was
studied in Ar and N2 matrixes at cryogenic temperatures. The reversed synfanti photoisomerization was observed
using UV-vis light. Rearrangement of FC(O)SCN into FC(O)NCS was observed in the neat liquid and in solution.
Under 193 nm (ArF excimer laser) irradiation, FC(O)NCS isolated in cryogenic Ar matrixes forms FC(O)SCN. At low
temperature, single crystals of the two constitutional isomers were obtained using a miniature zone melting procedure.
According to X-ray diffraction, they exclusively crystallize in their syn forms (Cs symmetry) in the orthorhombic crystal
system.(O)SCN was performed. In both the gas and
liquid states, FC(O)SCN and FC(O)NCS were found to exist as two conformers (Cs symmetry), in which the carbonyl
double bond (CdO) adopts a synperiplanar (syn) and an antiperiplanar (anti ) orientation with respect to either the
SCN or NCS group. For FC(O)SCN, the conformational enthalpy difference, ÄH = H(anti ) - H(syn), was
determined by matrix IR experiments to be 0.9(0.2 kcal mol-1. The conformational equilibria were evaluated by fastcooling
gaseous samples highly diluted in argon at different temperatures as cryogenic matrixes. The conformational
properties of both molecules were analyzed in terms of the hyperconjugative electronic effect applying the natural bond
orbital method. The kinetics of the thermal conversion of the high-energy anti into the syn FC(O)NCS conformer was
studied in Ar and N2 matrixes at cryogenic temperatures. The reversed synfanti photoisomerization was observed
using UV-vis light. Rearrangement of FC(O)SCN into FC(O)NCS was observed in the neat liquid and in solution.
Under 193 nm (ArF excimer laser) irradiation, FC(O)NCS isolated in cryogenic Ar matrixes forms FC(O)SCN. At low
temperature, single crystals of the two constitutional isomers were obtained using a miniature zone melting procedure.
According to X-ray diffraction, they exclusively crystallize in their syn forms (Cs symmetry) in the orthorhombic crystal
system.(O)SCN and FC(O)NCS were found to exist as two conformers (Cs symmetry), in which the carbonyl
double bond (CdO) adopts a synperiplanar (syn) and an antiperiplanar (anti ) orientation with respect to either the
SCN or NCS group. For FC(O)SCN, the conformational enthalpy difference, ÄH = H(anti ) - H(syn), was
determined by matrix IR experiments to be 0.9(0.2 kcal mol-1. The conformational equilibria were evaluated by fastcooling
gaseous samples highly diluted in argon at different temperatures as cryogenic matrixes. The conformational
properties of both molecules were analyzed in terms of the hyperconjugative electronic effect applying the natural bond
orbital method. The kinetics of the thermal conversion of the high-energy anti into the syn FC(O)NCS conformer was
studied in Ar and N2 matrixes at cryogenic temperatures. The reversed synfanti photoisomerization was observed
using UV-vis light. Rearrangement of FC(O)SCN into FC(O)NCS was observed in the neat liquid and in solution.
Under 193 nm (ArF excimer laser) irradiation, FC(O)NCS isolated in cryogenic Ar matrixes forms FC(O)SCN. At low
temperature, single crystals of the two constitutional isomers were obtained using a miniature zone melting procedure.
According to X-ray diffraction, they exclusively crystallize in their syn forms (Cs symmetry) in the orthorhombic crystal
system.(CdO) adopts a synperiplanar (syn) and an antiperiplanar (anti ) orientation with respect to either the
SCN or NCS group. For FC(O)SCN, the conformational enthalpy difference, ÄH = H(anti ) - H(syn), was
determined by matrix IR experiments to be 0.9(0.2 kcal mol-1. The conformational equilibria were evaluated by fastcooling
gaseous samples highly diluted in argon at different temperatures as cryogenic matrixes. The conformational
properties of both molecules were analyzed in terms of the hyperconjugative electronic effect applying the natural bond
orbital method. The kinetics of the thermal conversion of the high-energy anti into the syn FC(O)NCS conformer was
studied in Ar and N2 matrixes at cryogenic temperatures. The reversed synfanti photoisomerization was observed
using UV-vis light. Rearrangement of FC(O)SCN into FC(O)NCS was observed in the neat liquid and in solution.
Under 193 nm (ArF excimer laser) irradiation, FC(O)NCS isolated in cryogenic Ar matrixes forms FC(O)SCN. At low
temperature, single crystals of the two constitutional isomers were obtained using a miniature zone melting procedure.
According to X-ray diffraction, they exclusively crystallize in their syn forms (Cs symmetry) in the orthorhombic crystal
system.(O)SCN, the conformational enthalpy difference, ÄH = H(anti ) - H(syn), was
determined by matrix IR experiments to be 0.9(0.2 kcal mol-1. The conformational equilibria were evaluated by fastcooling
gaseous samples highly diluted in argon at different temperatures as cryogenic matrixes. The conformational
properties of both molecules were analyzed in terms of the hyperconjugative electronic effect applying the natural bond
orbital method. The kinetics of the thermal conversion of the high-energy anti into the syn FC(O)NCS conformer was
studied in Ar and N2 matrixes at cryogenic temperatures. The reversed synf