Журнал "Макрогетероциклы"

Yulia A. Glazova,^a Elena V. Lukovskaya,^a@ Yury V. Fedorov,^a,b Alla A. Bobylyova,^a Anna A. Moiseeva,^а Alexander V. Anisimov,^a and Olga A. Fedorova^a,b

^аChemistry Department, M.V. Lomonosov Moscow State University, 119991 Moscow, Russia

^bA.N. Nesmeyanov Institute of Organoelement Compounds of Russian Academy of Sciences, 119991 Moscow, Russia

^@Corresponding author E-mail: luchal2006@yandex.ru; tel.: +7(495)939 24 48; fax: +7(495) 932 85 68

DOI: 10.6060/mhc140490l

Macroheterocycles 2014 7(4) 373-379

Molecular sensors became very popular among the researches in these latter days due to the possibility to use them for development of new effective methods in the fields of biochemical analysis and environmental monitoring. Polythiophene derivatives, containing ionophoric residues, demonstrate changes in electrochemical characteristics during the complexation with different metal cations. Also some polythiophene derivatives demonstrating an optical response upon the complex formation with alkaline and alkaline-earth metals are known from the literature. Only a couple of polythiophene derivatives that can be considered as multiparametric sensors are known. The presence of thiophene chain in the ligand molecule allows detecting of metal cations using optical as well as electrochemical methods. In the present report the synthesis and investigations of crown-containing polythiophene derivative possessing optical and electrochemical characteristics as well as ability toward complex formation with alkaline-earth metals are given. The novel ligand has an extended chromophoric system with a donor crown-ether part at one end and acceptor benzothiazol residue at the other end. This kind of structure provides good optical characteristics in UV-Vis spectral range. The long-wavelength band in the absorption spectrum of donor-acceptor type compound is caused by charge transfer from donor to acceptor part at photoexcitation. Two thiophenic rings are introduced into the ligand to provide good electrochemical characteristics. The complex formation of crown-containing polyheterocyclic dye with magnesium perchlorate was investigated with a range of physical-chemical methods such as spectrophotometric titration, NMR spectroscopy, ESI-MS and cyclic voltammetry. The formation of “inclusive” type complex of dye with magnesium cation was detected. The complex formation produces changes in optical and electrochemical characteristics of ligand. It was also shown that the complex formation of crown-free ligand with magnesium perchlorate wasn’t observed because benzothiazolic residue doesn’t possess an affinity toward magnesium cation. Investigation of crown-containing part without long conjugated system demonstrated the complexation ability but it almost did not affect to the signal positions of the nearby protons in 1H NMR spectrum. Data, obtained by different physical-chemical methods are in a good agreement with each other and indicate that the molecule, having such a design can be used as a multiparametric sensor for alkaline-earth metals.

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