Quantum chemical calculations of the equilibrium structure, potential energy surface cross-sections along the nonrigid degrees of freedom of (CF3COOAg)2, (CHF2COOAg)2, (CH2FCOOAg)2, and (CH3COOAg)2 dimers and the corresponding monomers are presented. The B3LYP method with the augmented cc-pVTZ basis set for C, O, F atoms and the Stuttgart 1997 RSC basis set together with the relativistic effective potential for Ag atoms is used. It is shown that in all dimers the eight-membered ring is a rather rigid planar fragment, and the Ag atoms can be bonded with the bond order of 0.2 in dimers. Almost free rotation of acyclic groups around the C-C bond in (CH3COOAg)2 and (CF3COOAg)2 dimers transforms into a hindered one in the (CHF2COOAg)2 dimer, and further into the existence of syn- and anti-structures divided by a high rotation barrier in the (CH2FCOOAg)2 dimer. In monomers, the ratio of the internal rotation barriers is similar. With increasing number of fluorine substitution for hydrogen atoms in dimers the Ag-Ag bond length is found to increase (2.79 Е, 2.81 Е, 2.83 Е, 2.84 Е) and the ring rigidity to simultaneously decrease in the acetate-triflouroacetate series.

Ключевые слова: silver acetates, quantum chemical calculations, potential energy surface scanning