Intramolecular interactions in polynorbornanes

The intramolecular interactions involving bridging groups in a series of hetero bridged fused [n]polynorbornanes (n = 1–4) have been studied by using high-level ab initio method (G3-MP2B3) via the series of appropriate homodesmotic and protobranching compensated reactions. The calculated standard reaction enthalpies allowed us to obtain estimates of various nonbonding intramolecular interactions. The existence of rigid polynorbornane skeleton enabled us to “switch on” various interactions in a selective manner. The important intermolecular interactions comprise hydrogen bonding, hyperconjugation and non-bonding repulsive interactions (steric hindrance).