190843-93-7Relevant articles and documents
Lateral extension induces columnar mesomorphism in crucifix shaped quinoxalinophenanthrophenazines This paper is dedicated to Professor Makhlouf J. Haddadin on the occasion of his 80th birthday and 50 years of outstanding service to the American University of Beirut
El-Ballouli, Ala'A O.,Kayal, Himadri,Shuai, Chen,Zeidan, Tarek A.,Raad, Farah S.,Leng, Siwei,Wex, Brigitte,Cheng, Stephen Z.D.,Eichhorn, S. Holger,Kaafarani, Bilal R.
, p. 308 - 314 (2015)
Reported here is the columnar mesomorphism of board shaped dyes based on quinoxalino[2′,3′:9,10]phenanthro[4,5-abc]phenazine (TQPP) derivatives that was induced by an increase in lateral bulk. TQPP derivatives with protons, tert-butyl and 4-tert-butyl-phenyl groups in positions 2 and 11 are compared, as well as dodecylthio, dodecyloxy, phytanylthio, and phytanyloxy side-chains. Only derivatives with 4-tert-butyl-phenyl groups display columnar liquid crystal phases over wide ranges of temperature while all other TQPPs are not liquid crystalline except for the compound with tert-butyl groups and phytanyloxy side-chains that shows a Colr mesophase over a temperature range of 26 °C. The sole attachment of phytanyl groups does not effectively induce columnar mesophases. However, the lateral attachment of bulky groups to the TQPP core induces columnar mesomorphism because of the in-plane aspect ratio decrease and the favored twisted or helical π-stacking of the molecules in columns rather than the parallel co-planar packing.
Synthesis and binding investigations of novel crown-ether derivatives of phenanthro[4,5- abc ]phenazine and quinoxalino[2′,3′:9,10] phenanthro[4,5- abc ]phenazine
Jradi, Fadi M.,El-Ballouli, Ala'A O.,Al-Sayah, Mohammad H.,Kaafarani, Bilal R.
, p. 15 - 24 (2014)
The synthesis and binding investigation of novel crown-ether derivatives of phenanthro[4,5-abc]phenazine and quinoxalino[2′,3′:9,10] phenanthro[4,5-abc]phenazine sensors are reported. The binding studies of these sensors with an array of alkali and alkaline-earth metals are exploited using UV-vis, fluorescence and nuclear magnetic resonance spectroscopies. 2013
Synthesis and metal-binding studies of a novel pyrene discotic
Jradi, Fadi M.,Al-Sayah, Mohammad H.,Kaafarani, Bilal R.
, p. 238 - 242 (2008)
The synthesis of a novel bis-crown quinoxalino[2′,3′:9,10]phenanthro[4,5-abc]phenazine discotic and its binding properties to a series of alkali and alkaline-earth metals is reported. A schematic representation of the binding equilibrium of the sensor to the metal is proposed. The binding constant of the sensor to barium(II) was estimated to be 1.4 × 104 M-1 based on 1H NMR studies.
Synthesis of Distorted Nitrogen-Doped Nanographenes by Partially Oxidative Cyclodehydrogenation Reaction
Varghese, Eldhose V.,Gao, Chen-Feng,Chang, Yu-Lun,Chen, Hsing-Yin,Chen, Chia-Hsiang
, (2022/02/23)
A series of partially fused N-doped nanographenes (2–4) are synthesized via the oxidative cyclodehydrogenation of oligoaryl-substituted dibenzo[e,l]pyrene (1), and five, six, and seven new C?C bonds are formed, respectively, implying stepwise C?C bond fusion and extended π-conjugation. Single-crystal X-ray diffraction analysis of compound 4 a revealed that the presence of sterically demanding groups hindered the formation of planar and fully fused nanographene in the oxidative cyclodehydrogenation reaction step. Optical study of compounds 2 to 4 showed that extended π-conjugation leads to a regular stepwise bathochromic shift in the absorption and emission spectra. Furthermore, the HOMO–LUMO gaps of these compounds exhibit a decrease as C?C bond formation proceeds. Thus, the optoelectronic properties of nanographenes are highly dependent on the formation of new C?C bonds in the molecular skeleton.
