N-Substituted hydrazones of nickel complexes of β-octaethylporphyrin and tetraethyl ester of coproporphyrin I were obtained. These compounds can serve as intermediate compounds for the preparation of meso-functionalized derivatives of porphyrins by means of various reactions. In the first stage Vilsmeier-Haack reaction was carried out by the interaction of nickel complexes of β-octaethylporphyrin and tetraethyl ester of coproporphyrin I with N,N-dimethylformamide and phosphorus(V) oxochloride forming the so-called "phosphorus complex", which was hydrolyzed with saturated solution of sodium acetate. The corresponding meso-formyl derivatives of metal porphyrins were obtained as a result. Synthesis of the hydrazones was carried out by the reactions of meso-formyl derivatives with the hydrazines using trifluoroacetic acid as a catalyst. The result of the reaction was formation of hydrazones in the form of a mixture of E-and Z-isomers, which were separated using preparative thin layer chromatography. Thus a series of hydrazoneswith different substituents at the nitrogen atom was obtained. The structures of all obtained compounds were determined using the methods of NMR spectroscopy, electronic absorption spectroscopy and mass spectrometry. For nickel complex of tosylhydrazone derivative of β-octaethylporphyrin the crystal structure was determined using X-ray diffraction. X-ray analysis shows that porphyrin molecules in the crystal form dimers bonded by two hydrogen bonds between the hydrogen atom of the NH-group of hydrazone and the oxygen atom of the sulfonate groups.
The meso‐imino derivatives of the palladium (II) and nickel (II) complexes of coproporphyrins I and II and β‐octaethylporphyrin were obtained by the Vilsmeier formylation followed by interaction with amines. The metal complexes of the azomethines obtained were transformed to the corresponding complexes of cyclopentane and cyclopentane‐pyrrolidone fused porphyrin derivatives by thermolysis. The plausible mechanism of such transformations was suggested and substantiated with quantum chemical calculations. Meso‐cyano‐, meso‐hydroxy‐, and meso‐aminocarbonyl derivatives of β‐octaethylporphyrin were obtained by treatment of the corresponding meso‐imino derivatives with bases. Demetalation of the nickel complex of the meso‐ hydroxy‐β‐octaethylporphyrin led to formation of the free base derivative. The structures of new types of the porphyrin derivatives were determined via X‐ray powder diffraction analysis. The obtained types of porphyrins are promising candidates to use as photosensitizers in medicine applications due to their longer wave absorption combined with high stability.
New complexes of neptunyl(V) isothiocyanate
with 4′-aryl-substituted
2,2′:6′,2″-terpyridines (Terpy) and N,N-dimethylacetamide (DMA) were obtained: [(NpO2)(4′-Ph-Terpy)(DMA)(NCS)]·DMA, [(NpO2)(4′-(4-(CF3)C6H4)-Terpy)(DMA)(NCS)]·2H2O·DMA, [(NpO2)(4′-(3-BrC6H4)-Terpy)(DMA)(NCS)]·DMA, and [(NpO2)(4′-(2-(COOH)C6H4)-Terpy)(DMA)(NCS)]·DMA. The structures
of the compounds were determined with X-ray diffraction analysis.
The neptunium coordination polyhedra were found to be pentagonal bipyramids
with O atoms of the NpO2 groups in the apical positions
and the equatorial planes formed by three N atoms of the terpyridine
ligand, a N atom of the isothiocyanate anion, and an O atom of DMA.
The influence of the substituents of the Ar group on the crystal structure
is discussed. The IR spectra contain well-resolved bands of characteristic
vibrations of all groups in the complex. The electronic absorption
spectra are typical for neptunium(V) complexes and contain an intense
narrow absorption band belonging to an f–f transition with
a maximum of 988 nm and several long-wave satellites of lower intensity.
The substituted terpyridines were shown to be efficient for the extraction
of various valence forms of neptunium from the isothiocyanate solutions.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.