Аннотация:With the use of MALDI mass spectrometry and 29Si NMR spectroscopy, the molecular-mass compositions of oligomers prepared via partial acidolysis of PhSi(OMe)3 by acetic acid have been studied. Depending on the molar ratio of mPhSi(OMe)3 and nCH3COOH (m/n), a wide variety of oligophenylmethoxysiloxanes with average compositions of [(PhSiO1.5)m(OMe0.5)(3 – 2n)/m]p are formed. Through analysis of the molecular masses (MALDI, GPC) and 29Si NMR spectra of the products, the types of molecular structures have been determined. After 66.67–86.67% completion of the process, the change from linear, branched, cyclic, and polycyclic structures to fully condensed polyhedral structures is observed.