Effect of heteroatom (S/Se) juggling in donor-acceptor-donor (D-A-D) fused systems: synthesis and electrochemical polymerizationElectronic supplementary information (ESI) available: Cif files of compounds 1, 2 and 3, 1H and 13C NMR spectra of all new compounds and optimized structures, absolute energies, absorption spectra, picture of the HOMO and LUMO, and coordinates for the optimized structures of 1, 2, 3, P1, P2 and P3. CCDC 1412607, 1412608 and 1412747. For ESI and crystallographic data in

• Main Authors: Ghosh, Sirina, Das, Sarasija, Kumar, Neha Rani, Agrawal, Abhijeet R, Zade, Sanjio S
• Format: Article
• Language: English
• ISSN: 1144-0546; 1369-9261
• DOI: 10.1039/c7nj02394d

A series of nitrogen-bridged donor-acceptor-donor (D-A-D) type molecules, 1-3 , was synthesized using thiophene/selenophene as donors and benzothiadiazole(BTD)/benzoselenadiazole(BSeD) as acceptors. Compound 1 contains a sulfur (S) atom in both the donor and acceptor which was changed to selenium (Se) in 2 for the donor and in 3 for the acceptor. The juggling of S/Se atom(s) in the donor or acceptor unit helps in modulating the structural, photophysical, and electrochemical properties of the resulting compounds. As revealed from crystal structures, compounds 2 and 3 dimerize via S N and Se N interactions, respectively. Compounds 1-3 were successfully polymerized by electrochemical polymerization and the resulting polymers were studied electrochemically. Compounds 1-3 show high fluorescence quantum yields, positive solvatochromism, and high stokes shifts. Planarization of donor-acceptor-donor (D-A-D) systems through N-bridges with systematic alteration of S/Se atom(s) resulted in interesting fluorosolvatochromic molecules and their electrochemical polymers.