Isomerism of asymmetric dendrimers and stereoisomerism of alkanes

Abstract

Two extremes of isomerism in constructing acyclic chemical networks are considered. On the one hand, building blocks without symmetry generate dendrimers. On the other, tetradentate building blocks of full symmetry give stereoisomerism of alkanes. Dissimilarity characteristic theorem is applicable to both situations in generating and enumerating isomers. A new category of graph-theoretical trees, ones with finite color-coded links, is modeled for dendrimers and analyzed using the Cayley scheme. Bidentate, tridentate and tetradentate dendrimers are enumerated. A homologous series of polyol-type molecules is also enumerated. Concepts of chirotopicity and stereogenicity are found embodied within the counting scheme. This scheme indicates that irregular carbon nodes orderly dispose molecular chirality and are genuine ‘elements’ of chirality, even though this idea was once unpopular.