Microwave Spectrum and Structure of Formic Acid

摘要

The microwave spectra of five isotopic species of formic acid have been investigated, and values of the rotational constantsBandChave been obtained. For HC12OOH,B=12 055.1 Mc,C=10 416.0 Mc; for HC12OOD,B=11 762.5 Mc,C=9970.1 Mc; for DC12OOH,B=12 055.6 Mc,C=9955.8 Mc; for DC12OOD,B=11 759.9 Mc,C=9534.1 Mc; and for HC13OOH,B=12 053.7 Mc,C=10 378.9 Mc. The following structural parameters have been fitted to these rotational constants:rCsngbnd;H=1.085 A,rC=O=1.245 A,rCsngbnd;O=1.312 A,rOsngbnd;H=0.95 A, ang;OCO=124deg;18prime;, ang;COH=107deg;48prime;. The Cdblbnd;O bond has been estimated to have 75 doublehyphen;bond character. The torsional frequency was found to be 667plusmn;41 cmmdash;1and a barrier height of roughly 17 kcal/mole is indicated.