Fluoroform, as confirmed by both experimental and theoretical studies, can participate in improper H-bond formation, which is characterized by a noticeable increase in the fundamental stretching frequency ν(C-H) (so-called blue frequency shift), an irregular change of its integral intensity, and a C-H bond contraction. A Car-Parrinello molecular dynamics simulation was performed for a complex formed by fluoroform (F3CH) and deuterated methyl fluoride (FCD3) in liquid nitrogen. Vibrational analysis based on the Fourier transform of the dipole moment autocorrelation function reproduces the blue shift of the fundamental stretching frequency ν(C-H) and the decrease in the integral intensity. The dynamic contraction of the C-H bond is also predicted. The stoichiometry of the solvated, blue-shifted complexes and their residence times are examined. © 2006 Wiley-VCH Verlag GmbH & Co. KGaA.