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Complexation of metal cations with acyclic and macrocyclic nucleobase derivatives containing uracil and 2-thiocytosine units linked by polymethylene spacers was studied. The investigated compounds have demonstrated high extraction selectivity for the Ag+ ion over a large number of competitive cations (Na+, Ca2+, Co2+, Ni2+, Cu2+, Zn2+, Cd2+). The structure and composition of Ag+ complexes have been investigated by a variety of physical-chemical methods. The crystal structures of three Ag+ complexes with 2-thiocytosine have been established by X-ray analysis. To refine the composition of the complexes formed in solution, the self-diffusion coefficients have been determined by NMR spectroscopy. For the estimation of the most reliable complex structures, the combined analysis of NMR data and DFT calculations was successfully applied. It was shown that the tendency of 2-thiocytosine moieties to form N1-nitrogen coordinated complexes and the presence of a polymethylene spacer between amine groups in the pyrimidinophanes provides the formation of Ag+ mediated duplex-type multi-component complexes.

Pyrimidinophanes are macrocycles consisting of pyrimidine moieties bridged to each other with alkyl spacers. Most of the known pyrimidinophanes originate from pyrimidinic nucleobase uracil and its 5(6)-substituted derivatives. Diverse macrocyclic compounds with pyrimidine moieties have appeared during the last two decades, and in this review the synthesis and properties of the pyrimidinophanes studied have been described.

Intra-and intermolecular interactions in acyclic compounds containing nucleotide base (uracil and thymine) derivatives and their macrocyclic analogs (pyrimidinophanes) were studied by IR, UV, luminescence, and NMR spectroscopy. Molecules of these compounds include one or two N3-methylsubstituted or N3-unsubstituted uracil fragment or two adenine fragments linked through a hexamethylene spacer to an uracil, 5,5′-methylenediuracil or diphenylmethane fragment. The examined compounds almost all are characterized by π-π interactions and intramolecular hydrogen bonding between the terminal uracil or adenine fragments. Intramolecular association constants were determined and factors affecting them were discussed. Complex formation of acyclic and macrocyclic ligands with adenine and thymine derivatives was studied. The low values of the association constants were interpreted in terms of a competition between intra-and intermolecular bonding and very labile ligand structure.

Compounds consisting of two or three uracil fragments were synthesized by reaction of methyl-substituted uracil sodium salts with 1-(6-bromohexyl)-3,6-dimethyluracil or 1,6-dibromohexane. Treatment of these compounds with paraformaldehyde gave the corresponding pyrimidinophanes and acyclic compounds in which the uracil fragments are linked through methylene bridges. Uracil derivatives having no substituent on N3 were synthesized by reactions of silylated uracils with 1,3-bis(6-bromohexyl)uracil or 4,4′-(6-bromohexyloxy)diphenylmethane. The acyclic compound was converted into pyrimidinophane containing uracil fragments with N3H groups. A trinucleotide analog including uracil and two adenine fragments was synthesized from 1,3-bis(6-bromohexyl)uracil.

The reactions of 1,3-bis(5-bromopentyl)-5-methyl-or 1,3-bis(5-bromopentyl)-6-methyl-uracil with benzylamine afforded pyrimidinophanes containing the nitrogen atom in the polymethylene bridge. Single-crystal X-ray diffraction study and NMR and UV spectroscopic study in solution demonstrated that the phenyl and uracil fragments in the macrocycles are in spatial proximity. Unlike the known macrocycles containing the pyrimidine ring, the pyrimidinophanes under study are conformationally rigid.

Acyclic and macrocyclic compounds having different numbers of pyrimidine fragments and nitrogen atoms in the polymethylene bridges or in substituents at the pyrimidine rings reacted with 2,3,5,6-tetrachloro-1,4-benzoquinone and 1,4-benzoquinone according to the charge transfer scheme to give products with an ionic structure. The reaction was accompanied by protonation of nitrogen atoms in the polymethylene bridges or in substiuents at the pyrimidine rings and reduction of 2,3,5,6-tetrachloro-1,4-benzoquinone or 1,4-benzoquinone to 2,3,5,6-tetrachlorobenzene-1,4-diol or benzene-1,4-diol, respectively. The isolated products are dielectrics.

The reactions of disodium salts of N,N"-bis(2-mercapto-6-methylpyrimidin-4-yl)alkylenediamines with 1,3-bis(ω-bromoalkyl)-6-methyluracils afforded a series of macrocyclic compounds containing three pyrimidine fragments with different numbers of methylene groups in linking bridges.

The geometric parameters of dl- and d-tetranuclear iron(III) tartrates [Fe4(d-L)2(l-L)2(H2O)8]4–and [Fe4(d-L)4(H2O)8]4–(H4L is tartaric acid) were optimized using the molecular mechanics method (MIND program, Dashevskii–Plyamovatyi model).

The reactions of 1,3-bis(ω-bromobutyl- or -pentyl)-6-methyluracil with 1,3-bis(ω-ethylaminobutyl- or -pentyl)-6-methyluracil afforded pyrimidinophanes containing N atoms in bridging polymethylene chains. Individual geometric isomers of pyrimidinophanes were isolated. The structure of one of these isomers was established by X-ray diffraction analysis. Quaternization of the bridging N atoms with o-nitrobenzyl bromide gave rise to water-soluble pyrimidinophanes.

Formation of heteronuclear erbium(III), thulium(III), and iron(III) d- and dl-tartrates was studied by proton magnetic relaxation, pH-metry, and paramagnetic birefringence in combination with mathematical simulation. The paramagnetic birefringence constants mP of the complexes were calculated.

The catalytic effect of new amphiphilic pyrimidinic compounds with two ammonium head groups and different kinds of counterions, inorganic bromide anions and hydrophobic tosylate anions, was studied and compared with that of conventional cetyltrimethylammonium surfactants with bromide and tosylate counterions.

The cyclization of 1,3-bis(ω-bromoalkyl)uracils with sodium sulfide led to pyrimidinophanes, containing one uracil unit and an S atom in the spacer, macrocyclic structure was confirmed by X-ray data; the S atom in bridge can be oxidized into sulfoxide or sulfone or converted into sulfonium ion.

Cationic dimeric pyrimidinic surfactants have been synthesised; the aggregation and catalytic properties of supramolecular systems based on these surfactants and polyethyleneimine have been studied.

The reactions of stoichiometric amounts of sodium salts of 2-hydroxy-3-methyl-4-oxo-3,4-dihydropyrimidine or 2-hydroxy-3,6-dimethyl-4-oxo-3,4-dihydropyrimidine and dibromoalkanes in dimethylformamide were used to synthesize α,ω-bis(3-methyl- or 3,6-dimethyl-2,4-dioxo-1,2,3,4-tetrahydro-1-pyirimidinyl)alkanes with 1 and 3-5 methylene units in the hydrocarbon brigde.

pH-Metering and magnetic double refraction are used to determine the molar constant of magnetic double refraction of dysprosium monotartrate DyH2L+ (H4L is tartaric acid). A molecular mechanics technique (Dashevskii-Plyamovatyi model) was used to model the structure of the ligand and hydrate surroundings of dysprosium(III) in DyH2L+. Theoretical molar constants of magnetic double refraction calculated from the molecular mechanics data (CONKERR program) were compared with the experimental values; the most probable models of the surroundings of the dysprosium(III) are established.

The structures of the ligand and hydrate environments of dysprosium(III) have been determined for dysprosium(III) d - and dl -tartrates in aqueous solution.

A series of acyclic and macrocyclic nucleobase derivatives that contain uracil and 2-thiocytosine units linked by polymethylene spacers was prepared. The length of spacers as well as the oxidation number of sulfur atoms entering into the structure of the compounds was varied. The crystal structure of pyrimidinophane with hexa- and heptamethylene linkers was established by X-ray analysis. The metal ion-binding properties of pyrimidinophanes and their acyclic counterparts were investigated by liquid extraction and 1H NMR titration experiments. The compounds with 2-thiocytosine fragments revealed a high selectivity of extraction towards Ag+ ions. The stoichiometry of silver complexes and the binding constants have been determined. The antibacterial activity of these complexes was also discussed.

New pyrimidinophanes containing four uracil units connected with methylene bridges through the N(1) and C(5) atoms of pyrimidine rings were obtained by treatment of 1,4-bis(3,6-dimethyluracil-1-yl)butane with paraform.