L. A. Antina

Characteristic features of formation, synthesis, and properties of binuclear zinc(II) helicates with alkyl-substituted 3,3′-bis(dipyrrolylmethenes)

On the basis of spectrophotometric studies, it was demonstrated that complexation of hydrobromides of seven alkylated 3,3′-bis(dipyrrolylmethenes) (H2L · 2HBr) with zinc(II) acetate dihydrate in DMF (298.15 K) includes successive steps of formation of binuclear helicates of two types: [Zn2(AcO)2L] (heteroleptic single-helix complex) and [Zn2L2] (homoleptic double-helix complex). An increase in the degree of alkylation of the pyrrole rings of the ligands from 4 to 10 methyl groups induces an increase of overall complexation constants from 7.60 to 13.73. The synthesis of helicates [Zn2L2] was described. The products were studied by elemental analysis and IR, 1H NMR, U/Vis, and fluorescence spectroscopy. The effect of the helicand structure and the solvent nature on the chromophore and fluorescence properties of [Zn2L2] was discussed. The kinetic stability of zinc(II) with decamethyl-substituted 3,3′-bis(dipyrrolylmethene) in HCl-DMF medium was estimated.

Synthesis and spectral properties of the nickel(II) and mercury(II) helicates with 3,3′-bis(dipyrrolylmethenes)

The influence of the nature of the complexing metal on the optical properties of coordination compounds of bis(dipyrrolilmethenes) was studied.

Synthesis and photophysical properties of Cd(II) and Cu(II) complexes with decamethylated bis(dipyrrolylmethene)

Copper(II) and cadmium(II) complexes with bis(2,4,7,8,9-pentamethyldipyrrolylmethene-3-yl)-methane were synthesized. Influence of the complex-forming ion nature on the optical properties of [Cd2L2] and [Cu2L2] helicates was studied.

Synthesis and spectral properties of helicate of cobalt(II) with Bis(1,2,3,7,9-pentamethyldipyrrolylmethen-3-yl)methane

Reaction of cobalt(II) acetate tetrahydrate with compound I in a chloroform–methanol mixture in the presence of triethylamine afforded a binuclear homoleptic double-helical compound [Co2L2] II (Scheme 2). The electron absorption spectra of [Co2L2] solutions in organic solvents (С6Н6, DMF, CHCl3) contain two bands. Depending on the nature of the solvent, the most intensive band has a maximum in the range of 524–528 nm with a shoulder on the left slope at 490– 493 nm; a broadened less intense band of the charge transfer is in the range of 373–374 nm. Type of the electron absorption spectrum of helicate [Co2L2] in the organic solvents is consistent with the published data for the corresponding by composition Co(II) helicate with the structurally related bis(dipyrrolylmethenes) [4, 5]. In a non-polar inert benzene instead of the polar solvents, the electron-donating DMF and protonDOI: 10.1134/S1070363211010324

Kinetics of the dissociation of zinc(II) complexes with 3,3′-bis(dipyrrolylmethenes) in acetic acid-benzene binary solvent

A comparative study of the dissociation of zinc(II) helicates with a series of 3,3′-bis(dipyrrolylmethenes) (H2L) of [Zn2L2] composition in acetic acid-benzene binary proton donor solvent in the temperature range from 298.15 to 318.15 K is performed by means of electronic spectroscopy. Quantitative kinetic characteristics are determined and a stoichiometric mechanism of reaction is suggested. It is established that the protolytic dissociation of [Zn2L2] helicates proceeds according to a third-order kinetic equation of reaction. The effect of alkyl substituents in the pyrrol rings and nature of central 3,3′-spacer on lability of helicates is analyzed.

Kinetic stability of complexes of some d-metals with 3,3′-bis(dipyrrolylmethene) in the binary proton-donor solvent acetic acid-benzene

The kinetics of dissociation of Co(II), Ni(II), Cu(II), Zn(II), Cd(II), and Hg(II) binuclear homoleptic double-stranded helicates with bis(2,4,7,8,9-pentametyldipyrrolylmethen-3-yl)methane (H2L) of the [M2L2] composition in the binary proton-donor solvent acetic acid-benzene was studied. Protolytic dissociation of the helicates [M2L2] proceeds in accordance with the third order kinetic equation. Effect of the complexing metal nature is manifested in increased kinetic inertness in the following series of the helicates: [Cd2L2] < [Hg2L2] < [Cu2L2] < [Ni2L2] < [Zn2L2] < [Co2L2]. By the lability in similar environmental conditions the helicates [M2L2] are comparable to the metal complexes of distorted porphyrins and are much more inert than dipyrrolylmethenate mononuclear complexes.

NEW COLORIMETRIC AND FLUORESCENT CHEMOSENSORS BASED ON DIPYRROMETHENE DYES

Для цитирования: Антина Е.В., Березин М.Б., Гусева Г.Б., Бумагина Н.А., Антина Л.А., Вьюгин А.И. Новые колориметрические и флуоресцентные хемосенсоры на основе дипиррометеновых красителей. Изв. вузов. Химия и хим. технология. 2016. Т. 59. Вып. 6. С. 16-21. For citation: Antina E.V., Berezin M.B., Guseva G.B., Bumagina N.A., Antina L.A., V’yugin A.I. New colorimetric and fluorescent chemosensors based on dipyrromethene dyes. Izv. Vyssh. Uchebn. Zaved. Khim. Khim. Tekhnol. 2016. V. 59. N 6. P. 16-21.