P4VP and oligo(phenylenevinylene)-perylenebisimide mixed donor-acceptor supramolecular comb polymer complexes with improved charge carrier mobility

Abstract

Random donor‐acceptor (D‐A) supramolecular comb polymers were formed when hydroxyl functionalized donor and acceptor small molecules based on Oligo(phenylenevinylene) (named OPVCN‐OH) and Perylenebisimide (named UPBI‐PDP), respectively, were complexed with Poly(4‐vinyl pyridine) (P4VP). A series of random D‐A supramolecular comb polymers were formed by varying the ratios of UPBI‐PDP and OPVCN‐OH with P4VP. A 100% P4VP‐donor polymer complex [P4VP(OPV1.00)] and a 100% P4VP‐acceptor polymer complex [P4VP(UPBI1.00)] were also synthesized and characterized. Complex formation was confirmed by FT‐IR and 1H NMR spectroscopy. Solid state structural studies carried out using small angle X‐ray scattering and wide angle X‐ray diffraction experiments revealed altered packing of the D and A molecules in the complexes. Transmission electron microscopy images showed lamellar structures in the < 10 nm scale for the P4VP(OPV1.00), P4VP(UPBI1.00), and mixed P4VP (D‐A) complexes. The effect of the nanoscopic D‐A self‐assembly on the bulk mobility of the materials was probed using SCLC measurements. The mixed D‐A random complexes exhibited ambipolar charge transport characteristics with higher values for the average bulk hole mobility estimate. P4VP(OPV0.25 + UPBI0.75) exhibited an average hole mobility in the order of 10−2cm2 V−1 s−1 and electron mobility 10−5cm2 V−1 s−1. © 2016 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2016, 54, 2403–2412

Liquid crystalline supramolecular crosslinked polymer complexes of ditopic rylenebisimides and P4VP

“…Mesomorphic behavior observed in the pristine molecules was retained in the complexes P4VP‐PBI and P4VP‐NBI which was confirmed by POM and WXRD. Previous findings from our group also supports the observation that multiple sites of interaction, as is possible along the P4VP polymer backbone, can make up for the lack of strong individual point sites of interaction, resulting in overall improvement in alignment. The WXRD studies of the complexes versus pristine systems clearly demonstrated stretching of the rylenebisimide molecules due to hydrogen‐bonded intercalation of P4VP polymer chains.…”

“…In contrast to the soft supramolecular gel networks, bulk materials formed by supramolecular networks are seldom explored. In the recent years, the self‐assembly of P4VP with small π‐conjugated molecules was explored for their improvement in charge transport ability afforded by the enhanced π–π interactions . High degree of ordering of the semiconducting material could be achieved via the multiple hydrogen bonding interaction sites afforded by the P4VP.…”