Organic Chemistry: Current Research

Organic Chemistry: Current Research
Open Access

ISSN: 2161-0401

+44 1478 350008

NIR absorbing donor-acceptor based 1,1,4,4-Tetracyanobuta-1,3-Diene (TCBD) and cyclohexa-2,5- diene-1,4-ylidene-expanded TCBD substituted ferrocenyl phenothiazines


10th European Organic Chemistry Congress

March 21-22, 2019 | Rome, Italy

Madhurima Poddar

Indian Institute of Technology Indore, India

Posters & Accepted Abstracts: Organic Chem Curr Res

Abstract :

π Conjugated molecular systems containing sulfur (S) and nitrogen (N) atoms are of significant interest for various optoelectronic applications. A wide variety of S and N based heterocyclic units such as thiazoles, benzothiazoles, benzothiadiazole, phenothiazines and many more have been explored for non-linear optics (NLO), organic light emitting diodes (OLEDs), organic photovoltaics (OPVs) and organic field-effect transistors (OFETs). The incorporation of heterocyclic moiety into the chromophore backbone leads to higher chemical and thermal robustness. Phenothiazine allows variety of reactions including electrophilic substitution at the aromatic position, nucleophilic reaction at the N position, oxidation at the sulfur, etc. Therefore, a series of unsymmetrical (D–A–D1, D1–π–D–A–D1 and D1–A1–D–A2–D1) and symmetrical (D1–A–D–A–D1 ) type of phenothiazines were designed and synthesized by [2 + 2] cycloaddition–electrocyclic ring-opening reaction of ferrocenyl substituted phenothiazines with tetracyanoethylene (TCNE) and 7,7,8,8–tetracyanoquinodimethane (TCNQ). The photophysical, electrochemical and computational studies show strong charge-transfer (CT) interaction in the phenothiazine derivatives which can be tuned by the variation of number of TCNE/TCNQ acceptors. The phenothiazines show red shifted absorption in 400–900 nm region, resulting in low HOMO–LUMO gap which is supported by TD-DFT calculations. The electrochemical study exhibits reduction waves at low potential due to strong 1,1,4,4–tetracyanobuta–1,3–diene (TCBD) and cyclohexa–2,5–diene–1,4–ylidene–expanded TCBD acceptors. The incorporation of cyclohexa–2,5–diene–1,4–ylidene–expanded TCBD stabilizes the LUMO energy level to greater extent as compared to TCBD.

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