Metallo-Supramolecular Polymers
Résumé
Metallo-supramolecular polymers (MSPs) are polymeric entities whose macromolecules consist of metal ions and molecules with two or more chelate end-groups linked to chains by coordination bonds. A typical linear MSP is spontaneously formed upon mixing the molecular building blocks (unimers) with metal ions (ion couplers), because the activation energy of coordination binding is low. Therefore, the extent of the assembling process and thus also the length (degree of polymerization, DP) of the MSP chains is controlled by thermodynamics: high DP in the solid state at room (or working) temperature, but low DP in the solid state at increased temperature or in solution. Owing to these features, MSPs belong to the family of constitutional dynamic polymers (dynamers). Reversible assembling provides advantages in the processing of MSPs (low-viscous solutions or melts at preparation of functional films), responsiveness to certain external stimuli, possibility of post-synthesis tuning of their properties, and a potential for structure self-healing. The MSPs are promising materials mainly for advanced applications in fields such as optoelectronics and sensing.