Studies on photo switchable pendant indolyl furyl and thienyl fulgimides containing polypyrroles

Abstract

Aim of the research work is to examine the optical switching newlineproperties of polypyrrole containing thermally irreversible indolyl furyl and newlinethienylfulgimide units namely INDP FFP and TFP respectively The newlinepolypyrrole were prepared by electrodeposition on ITOglass substrate The newlinemonomers TFM and FFM were prepared by Stobbe condensation followed newlineby cyclization using trifluoroacetic anhydride TFA as dehydrating agent In newlinethe presence of TFA fulgide was condensed with 461pyrrolyl hexyloxy newlineaniline NPA to get monomers These monomers were electropolymerized newlineby cyclic voltammetry at constant potential 09 V to get FFP and TFP newlineThe monomer INDM was prepared by two consecutive Stobbe condensation newlinesubsequent hydrolysis and cyclization to obtain fulgide The reaction of newlinefulgide and 461pyrrolyl hexyloxy aniline NPA in the presence of newlineZnCl HMDS and resultant monomer was subjected to electropolymerization newlineto get polymer INDP on ITOglass substrate newlineAll the monomers were characterized by FTIR spectroscopy The newlinestretching band at 1746 cm and 1840 cm in all spectra of polymers newlineconfirms the presence of fulgimide group The methyl group in monomers newlinewas appeared at 2298 cmThe band at 1714 cm confirms the NCO newlinelinkage of fulgimide unit in all the monomers Pyrrole protons were observed newlineat 61 and 64 ppm for all the monomers in the HNMR spectra All newlinemonomers exhibit strong broad resonance signal in the range of 3645 ppm newlinecorresponds to methylene protons adjacent to ether Nsubstituted linkages newlineThe aromatic protons in all the monomers were resonated around 69 789 ppm newlineas broad signal The CNMR spectra of all the monomers demonstrated a newlineresonance signal at 180 1686 and 1675 ppm corresponding to ester carbonyl newlinegroup of fulgimides units All the monomers evidence four signals in between newline582694 ppm correspond to methylene carbon adjacent to etherester newlinelinkages The aromatic protons were appeared in the range of 1152 1584 ppm newlineTGA analysis reveals that stability and rigidity of polymers increases with newline