Benzothidiazole dibenzoic acid derivative (BTDB) is a well-known organic linker in various metal-organic framework structures as well as a fluorescent probe in biological systems. Here, we demonstrate that the radiative and non-radiative decay channels of BTDB can be interplayed and precisely controlled through concentration and hydrogen bond interactions as directly evidenced experimentally and theoretically. This leads to excited-state structural changes that significantly suppress the torsional motion around the Benzothidiazole moiety, leading to an enormous increase in the emission quantum yields from ~1% to 70%. These changes are associated with the existence of two equilibria where dimers and small-oligomers form in dimethylformamide (DMF), with high formation constants of 18,000 M-1 and 1.2 × 10 13 M-3 , respectively. These evolving species, i.e., the dimers and oligomers, are formed via hydrogen bonds between carboxylic acid groups present at the far-edge of the rod-like BTDB molecules. The estimated repeating number for this smalloligomer formation via bonded monomers is eight in DMF, as shown by emission spectra analysis. With deprotonation as a control experiment, these associated species can easily collapse to the initial monomer species, confirming the role of the hydrogen-bond formation on the observed phenomena. Theoretical studies and NMR experiments not only confirm the existence of the dimers, but also demonstrate the important role of the hydrogen bonds on the excited-state dynamics. These new findings provide a better understanding of the photophysical behaviors of organic linkers used in a wide range of chemical and biological applications.

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This paper presents an improved StrongARM latch comparator, designed and simulated in 90nm and 32nm CMOS technologies. The proposed design provides an improvement of 7% in energy efficiency, 14% in speed and an average reduction of 41% in the clock feedthrough, compared to the conventional design. The new architecture also minimizes the area by reducing the required transistors needed for the enhanced performance.

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