The EPR spectrum of a single crystal of chromium hexacarbonyl doped with Fe(CO)5thinsp;

摘要

Single crystals of Cr(CO)6have been doped with 0.05percnt; Fe(CO)5and ggr; irradiated at 77 K. The irradiated crystals revealed EPR spectra at 95 K of a species identified as Fe(CO)5minus;, present in two modifications A and B. Using Fe(CO)5+enriched in the isotope13C, the hyperfine tensors of the five carbon atoms of A were obtained; the unique13C hadapar;= 21 G andaperp;= 18 G; the other four hadapar;= 6.6 G andaperp;= 9.0 G. Measurement of the57Fe hyperfine interaction indicated the presence of a single Fe nucleus with apar;= l0 G and aperp;= 6 G. The two modifiactions A and B correspond to Fe(CO)5+molecules in which the unique Fendash;C bond is parallel to Crndash;C(1,2) or Crndash;C(3,4,5,6) bonds, respectively, in the pure Cr(CO)6crystal.