A new method of preparation of matrix-isolated molecules of formic aci
d at low temperatures has been developed. A set of experimental freque
ncies and intensities of the IR spectrum of monomer molecules of formi
c acid isolated in a low temperature argon matrix has been obtained. I
t is shown on the basis of analysis of the IR spectrum that the new me
thod eliminates association and decomposition of molecules of the acid
during preparation of the sample.