Design And Synthesis Of Organic Fluorescent Dyes And Their Applications In Chemosensing And Molecular Logic Gates

With the innovation of organic synthesis methods, a vairety of organic fluorescentdyes have been developed that play an important role in various areas of military andcivilian. In recent years, organic fluorescent dyes have been also often used inchemosensing and molecular logic gates. Fluorescent chemosensors combine molecularrecognition with some form of reporter. And the presence of target can be detected withorganic fluorescence dyes as the indicator. It is simple, fast, sensitive, and inexpensive.Molecular logic gates are an emerging interdiscipline, utilizing integrated circuits inelectronics on a molecular scale. And they have been widely applied in biosensing anddiagnostics, prodrug activation and drug delivery/release, intelligent mateirals andmolecular computers.The pyrene and8-hydroxy quinoline (8-HQ) are two of important fluorescent dyes.Therefore, we would prepare many fluorescent dyes with good fluorescence propertiesfrom these two dyes, and develop their applications in sensing and logic gates.1. We developed new fluorescent dyes based on pyrenylthiazoles and studied thefluorescence and UV/Vis properties of these dyes. The introduction of the phenylgroup could cause significant change and the effect of the methyl group was notobvious in fluorescence emission. From the single crystal data, we found anarrangement of benzene-thiazole stacking rather than pyrene-pyrene stacking. And thetheoretical (TD-DFT) calculations were carried out and the intramolecular chargetransfer was observed in these dyes. The theoretical calculations are in good agreementwith the expeirmental data. 2. We synthesized an aggregation-enhanced excimer emission (AEEE) fluorophore byintroducing chalcone into pyrene. Then we designed a probe with good watersolubility based on pyrenylchalcone for polyanion (Polyacrylic acid sodium salt andDNA) detection in aqueous media. Moreover, we found that the addition of biothiol(Cysteine) could lead to another different "Turn-on" change in fluorescence. And wemade this AEEE-active probe into a2-to-4molecular decoder. Our molecular decodercould work in pure water and be observed by naked eyes. And it wasenvironmentally-friendly (Instead of heavy metal ions and poisons, such as mercuryand cyanide). To our knowledge, the chalcone for AEEE-designing and itsapplications in the molecular decoder have not been reported before. This class ofAEEE-active luminophore is expected to be applied in more area in future.3.By using the new method in medicinal chemistry, we developed a new molecular logicgate that utilized a succinic imide labelled pyrene probe as the signal responser.Different from perylenebisimide and naphthalimide probes, this new logic gate canhandle both A+2+gand Hg in different pH without interference from other metal ions.After further investigating, owing to its molecular conjugative effect, we found thatthe functions of cytosine and thymine were integrated into an organic molecular. Thenwe desi+gn a molecular logic gate for H+, A+g，H22g and S" which has16kinds of inputcombinations and3different kinds of gate symbols (INHIBITOR，OR andIMPLICATION). Moreover，this molecular logic gate could be made into fluorescentpapers and firstly applied in the field of cryptography.4.We introduced the imide structure into8-HQ and made this new molecular logic gatef23or Zn++, Cd2+，Y and La)+selectively. Then we designed a five-input molecularlo2+gic gate by another input of Cu as INHIBITOR.5.We used the Vilsmeier-Haack-Arnold reaction, Corey-link reaction and Corey-Fuchsreaction to explore a new synthesis route of organic dyes from aromatic compounds.