@article { ISI:000355064000014, title = {Self-assembly directed template photopolymerization of perylenebisimide-poly (4-vinylpyridine): nano organization}, journal = {Polymer}, volume = {65}, year = {2015}, month = {MAY}, pages = {115-123}, publisher = {ELSEVIER SCI LTD}, address = {THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND}, abstract = {

A perylene bisimide derivative (PDP-UPBIAcry) having hydroxyl moieties at one termini and polymerizable acrylic units at the other termini was supramolecularly complexed with the pyridine units of Poly (4-vinyl pyridine) (P4VP), followed by photoinduced polymerization of the acrylic units to obtain lamellar organization in the \<10 nm range. H-1 NMR studies including variable temperature (20 degrees C-70 degrees C) measurements were undertaken in DMSO-d(6) (anhydrous, extra dry) to understand the interaction between PDP-UPBIAcry and P4VP. The aromatic perylene protons of PDP-UPBIAcry registered an upfield chemical shift while the pyridine protons of P4VP exhibited small downfield shift in their 1:1 supramolecular complex. The hydrogen bonding interaction between pyridyl nitrogen and phenolic OH group was also traced in non-polar media like CDCl3 in model complexes of 4-vinyl pyridine (4VP) with PDP-UPBIAcry. Wide angle X-ray diffraction (WXRD) technique was used to study the bulk structure. Transmission electron microscopy (TEM) imaging revealed highly ordered layered assembly formed upon complexation. Observation from DFT energy minimization studies were correlated with X-ray diffraction data of the supramolecular complex [P4VP (PDP-UPBIAcry)](1.0) to understand the nature of packing of PDP-UPBIAcry that lead to the formation of highly ordered lamellar stacks alternating with P4VP. The higher ordering in the supramolecular polymer complex was also confirmed by the quenching of fluorescence and reduced fluorescence life times of thin solid films of the [P4VP Poly(PDP-UPBIAcry)](1.0) sample. (C) 2015 Elsevier Ltd. All rights reserved.

}, keywords = {hydrogen bonding, P4VP, Perylenebisimide}, issn = {0032-3861}, doi = {10.1016/j.polymer.2015.03.062}, author = {Shinde, Shekhar and Asha, S. K.} } @article { ISI:000381302400017, title = {P4VP and oligo(phenylenevinylene)-perylenebisimide mixed donor-acceptor supramolecular comb polymer complexes with improved charge carrier mobility}, journal = {Journal of Polymer Science Part A-Polymer Chemistry}, volume = {54}, number = {15}, year = {2016}, month = {AUG}, pages = {2403-2412}, publisher = {WILEY-BLACKWELL}, address = {111 RIVER ST, HOBOKEN 07030-5774, NJ USA}, 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 H-1 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(-2) cm(2) V-1 s(-1) and electron mobility 10(-5) cm(2) V-1 s(-1). (C) 2016 Wiley Periodicals, Inc.

}, keywords = {donor-acceptor, oligo(phenylenevinylene), P4VP, Perylenebisimide, Self-assembly, structure-property relations, supramolecular comb polymer, supramolecular structures}, issn = {0887-624X}, doi = {10.1002/pola.28115}, author = {Saibal, B. and Chithiravel, Sundaresan and Asha, S. K.} } @article {45700, title = {Liquid crystalline supramolecular crosslinked polymer complexes of ditopic rylenebisimides and P4VP}, journal = {Journal of Polymer Science Part A-Polymer Chemistry}, volume = {55}, year = {2017}, month = {MAR}, pages = {951-959}, type = {Article}, abstract = {

Perylenebisimide and naphthalenebisimide (PBIPDP and NBI-PDP) end functionalized with pentadecyl phenol is designed as ditopic hydrogen bonding acceptors to form supramolecular crosslinked network with poly(4-vinyl pyridine) (P4VP). The pristine PBI-PDP has been grown as single crystals from DCM-MeOH (dichloromethane-methanol) mixture at room temperature, which revealed a P21 space group. Noticeably, the pentadecyl alkyl chain shields the aromatic perylene core on both sides resulting in the absence of p-p interaction in single-crystal assembly. The naphthalenebisimide derivative exhibits thermotropic liquid crystalline behavior, while both the molecules exhibits lyotropic liquid crystalline phases in tetrahydrofuran (THF), which were characterized using a combination of differential scanning calorimeter, X-ray diffraction, and polarized light microscopy. The hydrogen-bonded complex of both the rylenebisimides with P4VP preserves the mesomorphic properties in THF. The electron transport mobility measured by space charge limited current measurements reveals a two orders of magnitude increase in the charge transport in the P4VP complex compared to that of the pristine molecule. The average electron mobility obtained is mu(e, avg): 10(-3) cm(2)/Vs for P4VP-PBI compared to mu(e, avg): 10(-5) cm(2)/Vs for pristine PBI derivative. (C) 2017 Wiley Periodicals, Inc.

}, keywords = {crystal structures, ditopic rylenebisimide, hydrogen bonding, lyotropic liquid crystal, P4VP, Self-assembly, supramolecular crosslink, supramolecular structures}, issn = {0887-624X}, doi = {10.1002/pola.28449}, author = {Saibal, B. and Narayan, Rekha and Chithiravel, S. and Asha, S. K.} }