Colin Cameron, Allan H. Fawcett, Cecil R. Hetherington, Richard A. W. Mee and Frederick V. McBride
The step growth of a flexible AB2 monomer, normally considered to produce dendrimers or fractal molecules, as they are themselves self-similar to their branches, is frustrated by the formation of one cycle within each molecule, according to a Monte Carlo lattice study of the evolution of the topological trees that are embedded in three-dimensional space; the number of cycles of m residues is well fitted by the relationship Rm = K0 pam m-e, pa being the extent of reaction of the A groups; at the end of a polymerization of N0 monomers the total number of cycles, and of molecules, is given by the product of K0 and the Euler–Riemann function ξ(e) so there is a simple relationship between these quantities and the mean number average degree of polymerization at infinite time: N0 = K0 <x>n,∞ ξ(e).