Organotitanium fluorides (C5Me4R) TiF3 (R = H, Me, Et) sublimate with formation of crystalline dimers. From solution, we obtained crystals of dimers and tetramers. The tetramer [{(C5Me5) TiF3}(4)] irreversibly dissociates in the solid state to dimers (Delta H = 8.33 kcal mol(-1)). The variable- temperature H-1 and F-19 NMR spectroscopy measurements of the toluene-d(8) solution of [{(C5Me5)TiF3}(2)] revealed at 202 K one monomeric, two dimeric (with C-2h and C-s symmetry), two tetrameric (with D-2 and C-2v symmetry), and two trimeric (both C-2 symmetry) molecules. With the increase in temperature and dilution of the solution, the composition of the solution shifts to the smaller molecules. The thermodynamic and activation parameters for the reversible dissociation of dimers to monomers in the solution are Delta H = 9.2 kcal mol(-1), Delta S = 24.2 cal mol(-1) K-1, Delta H double dagger = 12.2 kcal mol(-1), Delta S double dagger = 9.7 cal mol(-1) K-1. The dissociation path with a weakly double-bridged transition-state dimer was proposed. The thermodynamic parameters for the reversible dissociation of the C-2v tetramer to the dimers in solution are Delta H = 7.9 kcal mol(-1) and Delta S = 26.8 cal mol(-1) K-1. From both tetramers, the D-2 molecule is 0.34(5) kcal mol(-1) lower in enthalpy and 6.5(5) cal mol(-1) K-1 lower in entropy than the C-2v molecule. The structures of both trimers were proposed. The low-temperature F-19 NMR spectra of the CDCl3 solution of [{(C5Me5)TiF3}(2)] are consistent with equilibria of a monomer, two dimers (with C-2h and C-s symmetry), and a trimer. The vapor pressure osmometric molecular mass determination of CDCl3 solution of [{(C5Me5)TiF3}(2)] at 302 K is consistent with the equilibrium of the dimer and the mo nomer.