RESUMO
Mossbauer spectra for l and d enantiomers of the Fe(phen)3Sb2(C4H2O6)(2);8H(2)O complex are reported. Four independent experiments show a small but reproducible energy shift of the Fe-Mossbauer spectra for the two enantiomers of 0.004+/-0. 002 mm/sec ( 1.9x10(-10) eV). This exceedingly small energy difference is comparable to that predicted by the parity-violating energy difference (PVED) using a Z6.2 scaling law applied to low Z ( Z = 6) molecules. Theoretical calculations suggest that the PVED for the Fe(phen)2+3 moiety should be smaller than this estimate, however, PVED effects of the chiral antimony tartrates are not taken into account.
RESUMO
Fully relativistic four-component electronic structure ab initio calculations including neutral current corrections are reported for a number of small chiral molecules that are of interest in the experimental search for differences in the vibrational spectra of the two enantiomers of handed molecules. The largest vibrational energy differences, of the order 0.2 Hz, are found in chiral methane derivatives which include an iodine substituent. The vibrational energy differences in CHBrClF are 7 and 2 mHz for the carbon-chlorine and carbon-fluorine stretching modes, respectively, which are 3 to 4 orders of magnitude smaller than the precision reported in recent experiments.
