Synthesis, Photophysical Studies of Blue‐Light‐Emitting Alternating Polymers from Substituted 9‐Sila Fluorenes and Substituted p‐Phenylacene

• Published in: ChemistrySelect (Weinheim) 2020-02, Vol.5 (8), p.2577-2580
• Main Authors: Gopalakrishnan, Jayasree, Hasija, Deepika C., Patil, Vishwanath R.
• Format: Article
• Language: English
• Subjects: Cyclic Voltammetry; Electroluminescence; p-hydroxy phenyl anthracene; Photoluminescence; Silafluorene
• ISSN: 2365-6549; 2365-6549
• DOI: 10.1002/slct.201904422

Five new alternating polymers were synthesized from 2,7‐dibromo‐3,6‐dimethoxy‐9‐sila fluorene with varied alkyl and aryl groups substituted at 9‐position and 2‐tert butyl‐9,10‐di (p hydroxyl phenyl) anthracene. The monomers and the polymers were synthesized in good yields at each stage of preparation and with high degree of reproducibility. The copolymers were soluble in common organic solvents like toluene, xylene, THF and chloroform. Chemical and optoelectronic characterizations of the polymers were done by 1H and 13C NMR, GPC, UV absorption, photoluminescence and cyclic voltammetric studies. Pure blue light emission, with the maximum absorption wavelength in the range of 445 to 457 nm and the PL quantum efficiency in the range of 0.55 to 0.91 were recorded for the synthesized copolymers in their solution in CHCl3. The ITO/CuPc/α‐NPD/ copolymer/ Alq3/LiF/Al devices fabricated from the polymers gave pure blue light emission irrespective of the substitution on silicon atom of the silafluorene moiety. The properties both photophysical and electrochemical, of the synthesized alternating polymers are quite suitable for the development of blue light emitting devices. New series of copolymers were successfully synthesized from 2,7‐dibromo‐3,6‐dimethoxy‐9‐sila fluorine and alkyl/ aryl substituted diphenyl acene. Polymers exhibited good solution processibility with a pure blue light emission. UV, PL and CV studies showed quantum efficiencies of the polymers in the range of 0.55–0.91. The ITO/CuPc/α‐NPD/ copolymer/ Alq3/LiF/Al devices fabricated from the polymers gave pure blue light emission irrespective of the substitution on silicon atom of the silafluorene moiety.