Fluorescence behavior of syndiotactic polystyrene and its derivative: Formation of a ground-state dimer in the solid state

The fluorescence behavior of syndiotactic polystyrene (SPS) and its derivative, syndiotactic poly (4-tert-butylstyrene) (SPTBS), in solution, gel and solid-state forms is examined in detail. The behavior of these polymers is also compared to isotactic and atactic polystyrene. The main fluorescence of SPS and SPTBS in the solid state is discovered to be the result of a ground-state dimer (GD), even in ultrathin films, where side-chain phenyl groups that fail to form a GD mainly exhibit intermolecular excimer formation. The structures of all racemo diads promote contact between the side-chain phenyl groups of a polymer chain and other polymer chain. This might be one reason for the fast crystallization of SPS. It is important that the main fluorescence of SPS is a result of a GD because SPS is expected to be a host polymer capable of orientating clathrate opto-functional guest molecules.