Excited State Proton Transfers in Hybrid Compound Based on Indoline Spiropyran of the Coumarin Type and Azomethinocoumarin in the Presence of Metal Ions

Spectral-luminescence properties of a hybrid compound containing a coumarin-type spiropyran and an azomethinocoumarin fragment in toluene-acetonitrile solution in the presence of Li+, Ca2+, Zn2+ and Mg2+ ions are reported. Two excited state proton transfers can occur in the hybrid compound—the transfer of a proton from the OH group of the 7-hydroxy coumarin tautomer to the N atom of the C=N bond of the azomethine fragment leading to green ESIPT fluorescence with a maximum at 540 nm and from the OH group of the 7-hydroxy coumarin tautomer to the carbonyl group of the pyrone chromophore, which leads to the formation of the 2-hydroxyl-tautomer T of coumarin with blue fluorescence with a maximum at 475 nm. Dependence of these excited state proton transfers on the metal nature and irradiation with an external UV source is discussed.

SYNTHESIS, STRUCTURE AND PROPERTIES OF COMPLEX COMPOUNDSOF COBALT (II) WITH BENZOXASINE DERIVATIVES

In this work, coordination compounds of Co (II) with derivatives of dihydro-4H-3,1-benzoxazines were synthesized by a chemical method and their composition, structure, and physicochemical properties were studied. ... According to the data of elemental analysis and analysis for metal, the obtained complex compounds have the composition ML2, where M is metal, L are ligands: 2- [2-hydroxyphenyl] -4,4-diphenyl-1,2-dihydro-4H-3,1benzoxazine (L1), 2- [2-hydroxy-5-nitrophenyl] -4,4-diphenyl-1 , 2-dihydro-4H-3,1-benzoxazine (L2), 2- [2hydroxynaphthyl] -4,4-diphenyl-1,2-dihydro-4H-3,1-benzoxazine (L3), 2- [ 2-hydroxynaphthyl] -4,4-diethyl-1,2dihydro-4H-3,1-benzoxazine (L4). The structure and properties of the obtained complex compounds were studied by IR spectroscopy. According to IR spectroscopy data, it was found that in all complex compounds, the ligand participates in the open azomethine form; coordination with the metal atom involves two oxygen atoms and a nitrogen atom of the azomethine fragment of the ligand. It was found that the ligand in the complex performs a tridentate chelate-bridging function. The structure of complex compounds of cobalt with derivatives of benzoxazines is proposed.