“Synthesis and characterization of new 1′,3,3′,4-tetrahydrospiro[chromene-2,2′-indole] derivatives” Doctoral Thesis

Author, institution: Miglė Dagilienė, Kaunas University of Technology

Science area, field: Physical Sciences, Chemistry

The Doctoral Dissertation is available and at the library of Kaunas University of Technology (K. Donelaičio St. 20, Kaunas).

Scientific Supervisor: Prof. dr. Vytas MARTYNAITIS (Kaunas University of Technology, Physical Sciences, Chemistry – 03P)

Scientific consultant: Prof. Habil. Dr. Algirdas ŠAČKUS (Kauno technologijos universitetas, Physical Sciences, Chemistry – 03P)

Dissertation defence board of Chemistry Science Field

Prof. Dr. Vytautas GETAUTIS (Kaunas University of Technology, Physical Sciences, Chemistry – 03P) – Chairman;
Dr. Eglė ARBAČIAUSKIENĖ (Kaunas University of Technology, Physical Sciences, Chemistry – 03P);
Dr. Svajus ASADAUSKAS (Institute of Chemistry of Center for Physical Sciences and Technology, Physical Sciences, Chemistry – 03P);
Prof. habil. dr. Vytautas MICKEVIČIUS (Kaunas University of Technology, Physical Sciences, Chemistry – 03P);
Prof. dr. Patrick ROLLIN (University of Orléans, France, Physical Sciences, Chemistry – 03P).

Annotation:

A new class of fast photochromic organic molecular switches was designed and synthesized. The reaction of Fisher’s base and analogous compounds with 2-chloromethyl-4-nitrophenol resulted in the formation of 1-alkyl-[2-(2-hydroxy-5-nitrophenyl)ethyl-1]-3,3-dimethyl-3H-indolium chlorides, which underwent spirocyclization by treatment with a base to afford 1′,3,3′,4-tetrahydrospiro[chromene-2,2′-indoles] representing a new class of heterocyclic compounds notable for the single C₃-C₄ bond of their pyran ring. Irradiation of the 1′,3,3′,4-tetrahydrospiro[chromene-2,2′-indole] solutions in acetonitrile with nanosecond laser pulses generated short-lived colored chromophores which thermally reverted back to the ground state over 10¹ – 10² ns.
1′,3,3′,4-Tetrahydrospiro[chromene-2,2′-indole] derivatives undergo transformations to the colored ring-open form possessing the 4-nitrophenolate or 4-nitrophenylazophenolate chromophore when treated with cyanide in acetonitrile solution buffered with sodium phosphate. They consequently show a distinct color change. This change can be measured spectrometrically or detected by the naked eye. Furthermore, these compounds in particular exhibit high selectivity and are not affected by halide and other anions which are common interferents in the conventional sensing schemes for cyanide. This new chemosensor exhibits high sensitivity to low concentrations of cyanide and also demonstrates a very fast response up to tens of seconds.