Amin, Md. Khairul, Rahman, Md. Mostafizur, Naher, Masnun, Islam, Tanjila, Ahmad, Md. Faruak, Khan, Md. Amran-al-taz, Khan, Mohammad Mizanur Rahman, Alam, Md. Ashraful, Younus, Muhammad, Biswas, Manash Kanti, and Haque, Yasmeen
A series of acceptor and donor substituted bis(alkoxy)phenyl ethynyl oligomers 4,4′-((2,5-alkyoxy-1,4-phenylene)bis(ethyne-2,1-diyl))bis(nitrobenzene) (alkyl = C 4 H 9 3a; C 8 H 17 3b and C 12 H 25 3c ) and 4,4′-((2,5-alkyoxy-1,4-phenylene)bis(ethyne-2,1-diyl))bis(methylbenzene) (alkyl = C 4 H 9 4a; C 8 H 17 4b and C 12 H 25 4c ) has been synthesized by the palladium catalyzed cross coupling reaction of 1,4-dialkoxy-2,5-diiodobenzene with appropriate alkynes. The newly synthesized products were characterized by UV–Vis, IR and multinuclear NMR spectroscopic techniques as well as elemental analyses. All the synthesized bis-(alkoxy)phenyl ethynyl derivatives exhibit good thermal stability ( T 5 = 329–347 °C) as evident by thermo gravimetric analysis. In nitrophenyl substituted 3a-c , emission is observed in the green region, while in tolyl substituted 4a-c , emission is observed in the blue region of the electromagnetic radiation. Continuous wave (CW) closed aperture Z-scan technique reveals the signature of third-order nonlinearity in the materials that are thermal in nature. [ABSTRACT FROM AUTHOR]