The Microwave Spectra and Molecular Structures of Trifluoromethyl Bromide, Iodide, and Cyanide

摘要

The pure rotational spectra of trifluoromethyl bromide, iodide, and cyanide have been studied in the microwave region. TheB0values in Mc/sec were determined as follows: 2098.06 for CF3Br79; 2078.50 for CF3Br81; 1523.23 for CF3I; 2945.535 for CF3CN14; 2855.859 for CF3CN15. The nuclear quadrupole couplings,eQq, are in Mc/sec: 619 for Br79; 517 for Br81; minus;2150 for I127; minus;4.70 for N14. With any reasonable assumption of bond angles,dCFis found to be 1.33plusmn;0.015A in each molecule. The other distances depend more strongly on the assumption of the bond angles. With ang;FCF assumed to be 108deg;plusmn;1deg;, as suggested from other similar molecules, the values,dCBr= 1.91plusmn;0.02A,dCI= 2.14plusmn;0.02A,dCC= 1.46plusmn;0.02A, are obtained, where the additional assumptionsdCF= 1.332A for CF3I anddCN= 1.158A for CF3CN are made.