Dynamic behavior of supramolecular comb polymers consisting of poly(2-vinyl pyridine) and palladium-pincer surfactants in the solid state

Inbal Davidi; Daniel Hermida-Merino; Keren Keinan-Adamsky; Giuseppe Portale; Gil Goobes; Roy Shenhar

doi:10.1002/chem.201303139

Dynamic behavior of supramolecular comb polymers consisting of poly(2-vinyl pyridine) and palladium-pincer surfactants in the solid state

Chemistry. 2014 Jun 2;20(23):6951-9. doi: 10.1002/chem.201303139. Epub 2014 May 14.

Authors

Inbal Davidi¹, Daniel Hermida-Merino, Keren Keinan-Adamsky, Giuseppe Portale, Gil Goobes, Roy Shenhar

Affiliation

¹ Department of Chemistry, The Institute of Chemistry and The Center for Nanoscience and Nanotechnology, Edmond J. Safra Campus, The Hebrew University of Jerusalem, Jerusalem, 91904 (Israel).

PMID: 24827547
DOI: 10.1002/chem.201303139

Abstract

When poly(2-vinyl pyridine) is combined with Pd-pincer-based organometallic surfactants, a mesomorphic structure forms due to weak stacking interactions between the pyridine units and the Pd-pincer headgroups. The weak binding between the surfactant and the polymer competes with the tendency of the aliphatic tails of the surfactant to crystallize. Here, we demonstrate that over extended periods of incubation, the crystallization tendency of the surfactant tails causes the surfactant molecules to detach from the polymer and gives rise to additional packing modes of the alkyl tails featuring higher crystalline order. The dynamic behavior of these aged structures was investigated by variable-temperature small-angle X-ray scattering (SAXS) and solid-state (13)C NMR, and revealed the influence of thermal changes on the molecular level, and how these changes propagate to the mesoscale structure.

Keywords: comb polymers; mesomorphic structures; phase separation; pincer complexes; poly(2-vinyl pyridine).