MOLECULAR-STRUCTURE AND ASSOCIATION OF DIPHENYLGUANIDINE IN SOLUTION

An experimental and theoretical study of the structure and aggregation of diphenylguanidine (DPhG) in non-polar and low-polarity solvents (C Cl4, C6H6, C2HCl3 and CHCl3) was performed. Dipole moments, IR spectra and average molecular weight measurements as a function of concentrat ion demonstrate that DPhG is strongly associated in the solvents studi ed, The dimerization constant in CCl4 is 192 +/- 7 dm(3) mol(-1). Expe rimental results and a theoretical discussion on the basis of MNDO-PM3 and -AM1 methods show that in low-polarity solvents DPhG exists in th e form of an asymmetric tautomer, the same as was found in the solid-s tate structure.