V. P. Rybalkin

The novel azomethine ligands for binuclear copper(II) complexes with ferro- and antiferromagnetic properties

A series of novel binuclear ferro- and antiferromagnetic Cu(2+) chelates of structurally broadly varied Schiff bases (derived from o-tosylamino(hydroxyl)benzaldehydes and monoalkylated o-phenylenediamine, o-aminophenol, o-aminothiophenol, 1,2-diaminobenzimidazole, 1-aminobenzimidazoline-2-thione) and β-diketimines (derived from 2,6-di-i-Pr-aniline) has been prepared. The tautomerism of the ligands and structureof their copper complexes have been studied with the use of IR, 1H NMR EPR and EXAFS spectroscopy. Molecular and crystal structure of a β-diketimine copper dimer has been determined by X-ray crystallography. The magnetic measurements (2–300 K) performed for all the complexes showed that the ferro- and antiferromagnetic character of the exchange interaction depends both on the structure of the coordination site (origin of the ligating centers) and the structure of the ligands (in particular, on the type of the cycle annelated to the bridging fragment). Whereas S-binding metal chelates 13 (X = NTs, Y = S, R = H) are diamagnetic, the complexes 15 with annelated azole moieties are ferromagnetic.

Photochromic Cation Sensors

ABSTRACT Novel photochromic chemosensors for alkali-, alkali-earth and d-metal cations were synthesized and their photochemical and complexing properties investigated with the use of UV/vis, IR, 1H/7Li NMR spectroscopy and quantum chemical calculations – DFT(B3LYP/6-31G).

Chemosensors based on N -(9-anthrylmethyl)-benzene-1,2-diamine

A number of N-(9-antrylmethyl)-N′-arylmethylidenebenzene-1,2-diamines and 1-(9-anthrylmethyl)-2-aryl-1H-benzimidazoles were synthesized by condensation of N-(9-anthrylmethyl)benzene-1,2-diamine with aromatic and heterocyclic aldehydes. Study on their luminescent properties and complexing ability showed that 2-{[2-(9-anthrylmethylamino)phenylimino]methyl}-5-methylphenol, 2-{[2-(9-anthrylmethylamino)phenylimino] methyl}-4-methoxyphenol, and 2-{[2-(9-anthrylmethylamino)phenylimino]methyl}-6-methoxy-4-nitrophenol are effective and highly selective chemosensors for H+ and Hg2+ ions.

N,N′-Bis(9-anthrylmethyl)diamines as fluorescent chemosensors for transition metal cations

N,N′-Bis(9-anthryl)-substituted diamines, imidazolidines, and hexahydropyrimidines were synthesized, and their luminescence properties and complexing ability were studied. N,N′-Bis(9-anthrylmethyl)ethane-1,2-diamine and N,N′-bis(9-anthrylmethyl)butane-1,4-diamine were found to be effective and selective PET chemosensors for Zn2+ and H+, respectively. 2-[1,3-Bis(9-anthrylmethyl)hexahydropyrimidin-2-yl]-6-methoxyphenol can be used as fluorescent chemosensor for mercury(II) cations.

Synthesis and structure of 1-[(3-hydroxybenzo[b]thiophen-2-yl)methylidene]-3-oxo-5-phenyl-1-pyrazolidinium-2-ide

Potentially tautomeric azomethine imine, 1-[(3-hydroxybenzo[b]thiophen-2-yl)methylidene]-3-oxo-5-phenyl-1-pyrazolidinium-2-ide has been prepared. According to X-ray diffraction, 1H, 13C, and 15N NMR and electronic spectroscopy, the compound exists as 3-hydroxybenzothiophene structure containing intermolecular hydrogen bond between the hydroxy group and the carbonyl oxygen of the pyrazolidone ring in crystal state. Quantum chemical calculations predict the possibility of OH and NH tautomeric forms.

Synthesis and photochromic properties of fulgides and fulgimides, 5-alkoxybenzo[ b ]furan derivatives

New heterocyclic fulgides, 3-[1-(5-alkoxy-2-methylbenzo[b]furan-3-yl)ethylidene]-4-(2-propylidene)dihydro-2,5-furandiones, and fulgimides, 1-(2-dimethylaminoethyl)-3-[(5-methoxy-2-methylbenzo[b]furan-3-yl)ethylidene]-4-(2-propylidene)dihydro-2,5-pyrroledione and 1-benzyl-3-[(5-methoxy-2-methylbenzo[b]furan-3-yl)ethylidene]-4-(2-propylidene)dihydro-2,5-pyrroledione, were synthesized. Electron spectroscopy and 1H NMR spectroscopy were used to establish that all the compounds obtained have Z-configuration and exhibit photo-chromic properties with high stability to photodegradation in solutions. Cyclic photoisomers of fulgides possess fluorescent properties and thermal stability.

Synthesis and photochromic properties of fulgides based on naphtho[1,2-b]furan and benzo[g]indole

Heteroaromatic fulgides and fulgimides are among the most promising photochromic compounds for three-dimensional optical data storage devices and optical molecular switches due to high stability of their initial and photoinduced forms [1, 2]. However, there are no data on fulgides based on naphtho-fused fivemembered heterocyclic compounds. With the goal of studying compounds of this sort, we have synthesized fulgides IIa and IIb by the Stobbe condensation of 1-(5-methoxy-2-methylnaphtho[1,2-b]furan-3-yl)ethanone (Ia) and 1-(5-methoxy-2-methyl-1-phenyl1H-benzo[g]indol-3-yl)ethanone (Ib) with diethyl 2-isopropylidenebutanedioate in the presence of sodium hydride [3] (Scheme 1). On the basis of the IR and H NMR spectra, the isolated products were assigned the structure of 3-isopropylidene-4-{1-(5-methoxy-2-methylnaphtho[1,2-b]furan-3-yl)ethylidene}tetrahydrofuran-2,5-dione (IIa) and 3-isopropylidene-4-{1-(5-methoxy-2-methyl-1phenyl-1H-benzo[g]indol-3-yl)ethylidene}tetrahydrofuran-2,5-dione (IIb). Both compounds are E isomers with respect to the C=C hetarylethylidene double

Photochromic benzo[g]indolyl fulgimide with modulated fluorescence

A new photochromic fulgimide, (E)-1-(anthracen-9-ylmethyl)-3-[1-(5-methoxy-2-methyl-1-phenyl-1H-benzo[g]indol-3-yl)ethylidene]-4-(propan-2-ylidene)pyrrolidine-2,5-dione, has been synthesized and found to exhibit fluorescence. The structure of this compound and intermediate fulgenates and amidofulgenic and fulgenic acids has been determined by electronic and vibrational spectroscopy, 1H and 13C NMR, and mass spectrometry. The amidofulgenic and fulgenic acids are capable of undergoing photoinduced reversible Z/E isomerization with respect to the C=C bond without subsequent cyclization, whereas fulgenates are converted to the corresponding cyclic structures. The new fluorescent fulgimide is transformed into the colored nonfluorescing cyclic isomer under UV irradiation. The reverse ring opening under visible light irradiation restores the fluorescence properties, which makes this compound a molecular fluorescence switch.

Acylated 2-(N-arylaminomethylene)benzo[b]thiophene-3(2H)-Ones: Molecular Switches with Varying Migrants and Substituents

Synthesis and properties of photochromic acylated 2-(-arylaminomethylene)benzo[]thiophene-3(2)-ones are described. Their structure largely depends on the nature of acyl migrant and in a less degree on N-aryl substituent.

Synthesis and structure of new 6-substituted 5-methyl-5,6-dihydrocyclohepta[ b ]indole-9,10-dicarboxylic anhydrides

Reactions of (2-chloro-1-methyl-1H-indol-3-yl)-2-oxoacetyl chloride with alk-3-enoic acids gave the corresponding 6-substituted 5-methyl-5,6-dihydrocyclohepta[b]indole-9,10-dicarboxylic anhydrides which showed fluorescent properties.