Rate constant calculations in the dimerization of diaminocarbene: a direct dynamics study

Generalized transition state theory calculations are performed on the dimerization of diaminocarbene [(H2N)2C:] (1) to tetrakis(amino)ethene [(H2N)2CC(NH2)2] (2). This process involves the formation of a double bond from two carbenes and therefore inclusion of correlation energy is vital. The density functionals BPW91, B3LYP and the QCISD(T)//MP2 model are used in the electronic structure calculations of reactants, transition states and products. The goal of this work is to gain insight into the mechanism of dimerization of the diaminocarbenes [(R2N)2C:] (R=H, Me), where experimental activation parameters are already available for R=Me.