Molecular organization of reactants in the kinetics and catalysis of liquid phase reactions: X. Synergism in the combined catalysis of urethane formation by organotin compounds and tertiary amines

The kinetics of the reaction of m-Cl-phenyl isocyanate with n-butanol in heptane catalyzed by tin tributylacetate and diazobicyclooctane is studied. The phenomenon of synergism in the catalysis of urethane formation is quantitatively described by the simulation of kinetics using the data on the equilibrium constants of association of the alcohol in the system and modern concepts on the reaction mechanism. The formation of a donor-acceptor complex between the catalysts and inclusion of this complex into the composition of new reactive heteroassociates with the participation of the monomeric and dimeric forms of the alcohol were the reasons fnr the nnnarMitive. action nf the. catalvsts in the reaction under study.