STRUCTURE PREDICTION OF ALKALINE ACTIVATED HYDROLYSIS LIGNIN BASED ON THE STUDY OF ITS MODEL COMPOUNDS

摘要

The difficulties of lignin structure determination by universal analytic methods impose new disparate approaches to put together and substantiate the experimentally gathered data.Elaborated computer models and fragments of the lignin molecule are largely utilized in computational chemistry.Prediction of the conformations and spatial structures of the basic monolignols and of the alkaline activated hydrolysis lignin(AAHL)in different solvents is of vital importance for a correct determination of their molecular orbitals and chemical properties.The most probable conformations(those with minimal energy)of monolignols and AAHL are computed by the semi-empirical method MOPAC2002 and also by the method of molecular mechanics MM2.The effect of the solvent is calculated again with MOPAC2002.