An Acridone‐Based Fluorescent Chemosensor for Cationic and Anionic Species, and Its Application for Molecular Logic Operations

Primordial Molecular 1-Bit Magnitude Comparator in Consort with Excitation-Guided Mouldable Logic Systems: A Guided Design of Regular Interactions between Molecules

In addition to designing certain excitation modulated logic systems, we have created the first-ever genuine molecular 1-bit magnitude comparator, using acid and base guided varied absorption responses at separate channels. Designed and manufactured Bifunctional Bis(indolyl)methane Derivative (1) demonstrates distinct optical responses (in UV-visible and fluorescence mode) to a range of chemical stimuli (acid, base, Hg2+, Cu2+, EDTA, GSH, etc.) in aqueous medium. Intriguingly, the compound's excitation-modulated fluorescence responses appeared to change at different detection channels depending on whether the aforementioned analytes were present or not. We have proposed not only an excitation driven logic system with switchable molecular IMPLICATION and XNOR logic gates, but also a molecular 1-bit magnitude comparator in our proposal. A second excitation driven logic system with switchable molecular COMPLEMENT and NOR logic gates was also designed with two different optical channels and used Hg(II) & Cu(II) as chemical inputs.

Acridino-Diaza-20-Crown-6 Ethers: New Macrocyclic Hosts for Optochemical Metal Ion Sensing

Acridino-diaza-20-crown-6 ether derivatives as new turn-on type fluorescent chemosensors with an excellent functionality and photophysical properties have been designed and synthesized for metal ion-selective optochemical sensing applications. Spectroscopic studies revealed that in an acetonitrile-based semi-aqueous medium, the sensor molecules exhibited a remarkable fluorescence enhancement with high sensitivity only toward Zn2+, Al3+ and Bi3+, among 23 different metal ions. Studies on complexation showed a great coordinating ability of logK > 4.7 with a 1:1 complex stoichiometry in each case. The detection limits were found to be from 59 nM to micromoles. The new ionophores enabled an optical response without being affected either by the pH in the range of 5.5-7.5, or the presence of various anions or competing metal ions. Varying the N-substituents of the new host-backbone provides diverse opportunities in both immobilization and practical applications without influencing the molecular recognition abilities.