The high reactivity of p-xylylene is found to be consistent with the calculations of Coulson on the electronic structures of singlet and triplet states of this molecule. p-Xylylcne is diamagnetic at low temperature and yet is extremely reactive toward mono-and diradicals forming a, a'-disubstituted derivatives of p-xylylene and linear copoymers, respectively. The reactivity of p-xylylene is so much greater than that of olefinic monomers that ...