“…Different factors determining the structural features of dimers, including both competition between different conformations, as well as competition between inter molecular versus intra molecular dimerization, have been investigated . Short-chain polyester linkers of varying lengths were end-functionalized with coumarin derivatives to study their dimerization behavior. , By incorporating a methyl substituent on coumarin, both the stereochemistry and photoreactivity could be controlled. Using unsubstituted structures was shown to lead to a preferential head-to-head conformation of dimers, while the methyl substituent led to exclusive formation of only head-to-tail conformation.…”