Electrochromic properties of a novel low band gap conjugated copolymer based on 1,4-bis(2-thienyl)-naphthalene and 3,4-ethylenedioxythiophene

Thermal and solvatochromic effects on the emission properties of a thienyl-based dansyl derivative

Environmental conditions have a profound effect on the photophysical behavior of highly conjugated compounds, which can be exploited in a large variety of applications. In this context, we use a combination of experimental and computational methods to investigate thermal and solvatochromic effects on the fluorescence properties of a dansyl derivative bearing a thienyl substituent, namely 2-(3-thienyl)ethyl dansylglycinate (TEDG). In particular, we analyze how the solvent polarity and temperature affect the ground and excited state energies of TEDG by using time-resolved and steady-state fluorescence techniques. We determine the changes in dipole moment of the TEDG molecule upon photoexcitation, as well as the solvent polarity effects on the excited state lifetime. Besides, we provide theoretical modeling of the HOMO–LUMO orbitals and the vertical absorption and emission energies using time-dependent density functional theory (TDDFT) as well as the polarizable continuum model (PCM) to include the solvent contribution to the absorption and emission energies. Our results show that the emission mechanism of TEDG involves locally excited states derived from hybrid molecular orbitals, accompanied by a moderate variation of the molecular dipole moment upon light excitation. Our findings demonstrate that TEDG exhibits desirable fluorescence properties that make it a promising candidate for use as a photoactive material in electrochromic, optical thermometry, and thermography applications.

We use a combination of experimental and computational methods to investigate thermal and solvatochromic effects on the fluorescence properties of a dansyl derivative bearing a thienyl substituent, 2-(3-thienyl)ethyl dansylglycinate (TEDG).

Synthesis and characterization of donor–acceptor type conducting polymers containing benzotriazole acceptor and benzodithiophene donor or s-indacenodithiophene donor

Two D–A type copolymers were synthesized and characterized by a series of methods. Both copolymers showed high optical contrasts, fast response time and high coloration efficiency. In summary, they could be candidates for electrochromic applications.