Decoupling Optical Properties in Metallo-Supramolecular Poly(p-phenylene ethynylene)s

Abstract

The self-assembly polymerization of ditopic macromolecules through metal−ligand binding is an attractive framework for the preparation of high-molecular-weight metallo-supramolecular polymers. This approach was utilized here for the polymerization of a conjugated macromonomer (1) that was derived by functionalizing a low-molecular-weight poly(2,5-dialkoxy-p-phenylene ethynylene) (PPE) core with 2,6-bis(1‘-methylbenzimidazolyl)pyridine (Mebip) ligands on the two terminal positions. To minimize electronic interactions between the PPE moieties and the metal−ligand complexes, nonconjugated hexamethylene spacers were introduced between the PPE and Mebip building blocks. The supramolecular polymerization of macromonomer 1 with equimolar amounts of Zn2+ or Fe2+ resulted in polymers, which exhibit appreciable mechanical properties (loss moduli of [1·Zn(ClO4)2] n and [1·Fe(ClO4)2] n at 25 °C are ca. 450 and 610 MPa, respectively), but on account of their dynamic, reversible nature offer the ease of processing of low-molecular-weight compounds. The optoelectronic properties of these metallopolymers are similar to those of the parent PPE and demonstrate that the functionalities of semiconducting building blocks and coordination chain extenders can be effectively decoupled by a short, nonconjugated spacer.

Luminescent Mechanochromic Sensors Based on Poly(vinylidene fluoride) and Excimer‐Forming p‐Phenylene Vinylene Dyes

“…Fueled by academic curiosity and the potential for use in applications that range from security features, [1] lightemitting diodes, [2] lasers, [3] to chemical sensors, [4] the development of luminogenic polymers [5] is attracting much interest in laboratories around the world. We recently developed a new family of stimuli-responsive luminogenic polymers, which change their emission color upon exposure to a range of stimuli.…”

Optically healable supramolecular polymers

“…This design was based on the assumption that the hydrophobic core and the polar metal-ligand motif would phase separate 16 . Metal-Mebip complexes were previously used to self-assemble polymeric materials [17][18][19][20][21] , and their optical properties seemed appropriate for optical healing 22 (see below). To probe how the metal ion affects the materials' properties, 3 was self-assembled with Zn(NTf 2 ) 2 Published in " " which should be cited to refer to this work.…”

Fluorescent Fe(II) metallo-supramolecular polymers: metal-ion-directed self-assembly of new bisterpyridines containing triethylene glycol chains

“…After a successful study of the substituent effects of BTPYs with electron-donating methoxy groups for change in the photophysical properties of Ru(II)-MEPEs, we have designed new BTPY with bulky electron-donating triethylene glycol (TEG) chains to investigate the substituent effects on the photophysical properties of Fe(II)-MEPEs. The Fe(II) ion generates stable Fe(II)-MEPEs with a well-defined octahedral coordination geometry, but fluorescent Fe(II)-MEPEs have not been reported so far 4,[8][9][10][11] to our knowledge; however, it is well known that Fe(II) ions quench the fluorescence of Fe(II)-MEPEs bearing BTPY 9,12 or 2,6-bis(1¢-methylbenzimidazolyl)-pyridine. 13 Therefore, we chose Fe(II) ions for the study of substituent effects on fluorescent properties in metallo-supramolecular polymers.…”