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Four new manganese(II) complexes, based on dinitro and tetranitrothiacalix[4]arenes, were synthesized and characterized from structural points of view in the crystalline phase. It was revealed that thiacalix[4]arenes decorated with two and four electron withdrawing groups, when combined with MnCl2, afforded the formation of similar tetranuclear complexes 1 and 2a with two non-equivalent metal ions and a rhombic geometry of the metallic cluster core. The distortion of the coordination sphere of metal cations within the obtained complexes was found to be dependent on the number of nitro groups located at the upper rim of the macrocyclic backbone, adopted in cone conformation. The tetranuclear complex 2b of a different type, displaying the formation of a dinuclear cluster core, crystallized in a non-centrosymmetric space group was obtained, when tetranitrothiacalix[4]arene, adopted in a partial cone conformation, was involved in coordination with manganese(II) cations. The switching of coordination behavior for the macrocyclic ligand in 2b was achieved due to the presence of upper-rim-disposed electron-withdrawing nitro groups, increasing the flexibility of the macrocyclic backbone by breaking the H-bonding between the OH phenolate moieties within the ligand structure. Finally, the use of 2,2′-bipyridine as an auxiliary ligand in coordination with tetranitrothiacalix[4]arene and manganese(II) cations led to the third type complex formation 3, where the macrocycle platform adopted in a 1.2-alternate conformation.

The building of new Supramolecular Coordination Containers obtained through the linking of tetrasulfonylcalix[4]arene (3-4H) based transition metal tetra- or trinuclear clusters by succinic acid (suc) as a flexible aliphatic connector possessing high conformational mobility and rotational freedom, produced a variety of three different polynuclear species in the crystalline phase, which were characterized by X-ray diffraction on single crystals and powder. In the case of CoII and NiII cations, the formation of unique chiral-induced isomorphous supramolecular architectures generated by interconnection of dimeric M8-cages with the co-crystallized M(OH)2DMF4 neutral species via H-bonding was observed. Moreover, it was found that, in contrast to what was observed with NiII cations, the use of Cobalt(II) ions in the same multicomponent system, led to the formation of achiral M8-cages which was characterized by the presence of both left- and right-handed succinic acid moieties within the supramolecular entity structure. Finally, the coordination of ZnII cations with 3-4H and succinic acid produced the generation of dimeric M6-cages where two trinuclear [Zn3-3]2+ cationic clusters were bound by two succinic carboxylate units.

The first example of an asymmetric reaction of ortho-lithiatied Ugi's amine with tetracoordinated phosphorus(v) chloride has been demonstrated.

A series of new 2-hydroxy-3-methoxybenzylidenethiazolo[3,2-a]pyrimidines with different aryl substituents at the 5 position are synthesized and characterized by 1H/ 13C NMR and IR-spectroscopy and mass-spectrometry, as well as single crystal X-ray diffraction (SCXRD). It was demonstrated that the type of hydrogen bonding can play a key role in the chiral discrimination of these compounds in the crystalline phase. The hydrogen bond of the O–H...N type leads to 1D supramolecular heterochiral chains or conglomerate crystallization in the case of the formation of homochiral chains. The hydrogen bond of O–H...O type gave racemic dimers, which are packed into 2D supramolecular layers with a parallel or angular dimers arrangement. Halogen bonding of the N...Br or O...Br type brings a new motif into supramolecular self-assembly in the crystalline phase: the formation of 1D supramolecular homochiral chains instead 2D supramolecular layers. The study of cytotoxicity against various tumor cells in vitro was carried out. It was found that 2-hydroxy−3-methoxybenzylidenethiazolo[3,2-a]pyrimidines with 3-nitrophenyl substituent at C5 carbon atom demonstrated a high efficiency against M-HeLa (cervical adenocarcinoma) and low cytotoxicity against normal liver cells.

The coordination diversity of a novel N4-ligand and its sodium complex toward cobalt(ii) ions was studied.

Racemic and enantiopure ferrocene-based

Transition-metal mediated white phosphorus activation is of high interest as an ecological alternative to P

A series of D-π-A, D-π-D'-π-A, D-π-A'-π-A nonlinear optical chromophores with vinylene π-electron bridges or bridges with π-deficient/π-excessive heterocyclic moieties along with the corresponding precursors D-vinylene, D-π-D', D'-π-A, D-π-A' and A'-π-A are synthesized and studied both experimentally and computationally. The effect of the heterocycle in the π-electron bridge on the oxidation/reduction potentials and the energy gap (ΔEel ) is investigated in detail. The properties of the D-π-A'(D')-π-A chromophores are shown to correlate with those of building blocks: the oxidation potential is determined by the D-vinylene, and the reduction potential is determined by A'(D')-π-A truncated compounds. The contribution of the acceptor to the oxidation potential of chromophores in comparison with those of the precursors was estimated and analyzed in terms of electronic communication between the end groups. A good correlation between the ΔEel and the chromophores' first hyperpolarizability is revealed.

Trialkyl phosphonium derivatives of vinyl-substituted p-chlorophenol were synthesized here by a recently developed method of preparing quaternary phosphonium salts from phosphine oxides using Grignard reagents. All the derivatives with a number (n) of carbon atoms in phosphonium alkyl substituents varying from 4 to 7 showed pronounced uncoupling activity in isolated rat liver mitochondria at micromolar concentrations, with a tripentyl derivative being the most effective both in accelerating respiration and causing membrane potential collapse, as well as in provoking mitochondrial swelling in a potassium-acetate medium. Remarkably, the trialkyl phosphonium derivatives with n from 4 to 7 also proved to be rather potent antibacterial agents. Methylation of the chlorophenol hydroxyl group suppressed the effects of P555 and P444 on the respiration and membrane potential of mitochondria but not those of P666, thereby suggesting a mechanistic difference in the mitochondrial uncoupling by these derivatives, which was predominantly protonophoric (carrier-like) in the case of P555 and P444 but detergent-like with P666. The latter was confirmed by the carboxyfluorescein leakage assay on model liposomal membranes.

Redox properties of monoiminoacenaphthenes (MIANs) were studied using various electrochemical techniques. The potential values obtained were used for calculating the electrochemical gap value and corresponding frontier orbital difference energy. The first-peak-potential reduction of the MIANs was performed. As a result of controlled potential electrolysis, two-electron one-proton addition products were obtained. Additionally, the MIANs were exposed to one-electron chemical reduction by sodium and NaBH4. Structures of three new sodium complexes, three products of electrochemical reduction, and one product of the reduction by NaBH4 were studied using single-crystal X-ray diffraction. The MIANs reduced electrochemically by NaBH4 represent salts, in which the protonated MIAN skeleton acts as an anion and Bu4N+ or Na+ as a cation. In the case of sodium complexes, the anion radicals of MIANs are coordinated with sodium cations into tetranuclear complexes. The photophysical and electrochemical properties of all reduced MIAN products, as well as neutral forms, were studied both experimentally and quantum-chemically.

The row of metallocyclic dinuclear gold(I) complexes with cyclic diphosphines, namely, P-pyridylethyl-substituted 1,5-diaza-3,7-diphosphacyclooctanes, has been obtained. Further interaction of the dinuclear gold(I) complexes with copper(I) iodide gave the first examples of hexanuclear AuI/CuI complexes containing two unusual trinuclear AuICu2I2 fragments. The structures of di- and hexanuclear complexes were confirmed by NMR spectroscopy, ESI mass spectrometry, elemental analysis, and single-crystal X-ray diffraction. All of the obtained complexes are moderate emitters in the solid state. Dinuclear gold(I) complexes displayed a greenish emission with the maxima in the emission spectra at ca. 550 nm. The obtained hexanuclear heterobimetallic AuI/CuI complexes are triplet solid-state blue emitters with the maximum in the emission spectra at 463 and 484 nm. According to the TD-DFT calculations, the observed emission of all studied complexes had a triplet origin and was caused by the 3CC or 3(MLCT) T1 → S0 transitions for dinuclear and hexanuclear complexes, respectively.

The title hydrated copper(I)–L-cysteine–chloride complex has a polymeric structure of composition {[Cu16(CysH2)6Cl16]·xH2O} n [CysH2 = HO2CCH(NH3 +)CH2S− or C3H7NO2S], namely, poly[[tetra-μ3-chlorido-deca-μ2-chlorido-dichloridohexakis(μ4-L-cysteinato)hexadecacopper] polyhydrate]. The copper atoms are linked by thiolate groups to form Cu12S6 nanoclusters that take the form of a tetrakis cuboctahedron, made up of a Cu12 cubo-octahedral subunit that is augmented by six sulfur atoms that are located symmetrically atop of each of the Cu4 square units of the Cu12 cubo-octahedron. The six S atoms thus form an octahedral subunit themselves. The exterior of the Cu12S6 sphere is decorated by chloride ions and trichlorocuprate units. Three chloride ions are coordinated in an irregular fashion to trigonal Cu3 subunits of the nanocluster, and four trigonal CuCl3 units are bonded via each of their chloride ions to a copper ion on the Cu12S6 sphere. The trigonal CuCl3 units are linked via Cu2Cl2 bridges covalently connected to equivalent units in neighboring nanoclusters. Four such connections are arranged in a tetrahedral fashion, thus creating an infinite diamond-like net of Cu12S6Cl4(CuCl3)4 nanoclusters. The network thus formed results in large channels occupied by solvent molecules that are mostly too ill-defined to model. The content of the voids, believed to be water molecules, was accounted for via reverse Fourier-transform methods using the SQUEEZE algorithm [Spek (2015). Acta Cryst. C71, 9–18]. The protonated amino groups of the cysteine ligands are directed away from the sphere, forming N—H...Cl hydrogen bonds with chloride-ion acceptors of their cluster. The protonated carboxy groups point outwards and presumably form O—H...O hydrogen bonds with the unresolved water molecules of the solvent channels. Disorder is observed in one of the two crystallographically unique [Cu16(CysH2)6Cl16] segments for three of the six cysteine anions.

A comparative analysis of the molecular and crystal structures is performed for 5-[(diphenylphosphoryl) methyl]-4-phenyl-2,4-dihydro-3H-1,2,4-triazole-3-thione (1) in individual crystal (1a) and a crystal solvate with dimethylformamide (DMF) in the 1:1 ratio (1b). The crystals of both modifications have the identical geometries of the molecule of the key compound, and the crystals (despite their different crystal systems and unit cells parameters) are characterized by the formation of an identical one-dimensional supramolecular motif in them due to classical N–H...O hydrogen bonds and weaker noncovalent – C-H ... S interactions in crystal 1a and CH ... N in crystal 1b. A tetragonal packing of one-dimensional motifs oriented along the smallest unit cell parameter are observed in both cases. Solvate molecules are localized in zero-dimensional cavities in crystal 1b. Despite a denser molecular packing in crystal 1b, the solid-state phase transformation is observed for its polycrystalline sample, and the powder X-ray diffraction method shows that it partially transforms into form 1a with time. The latter form is characterized by a less dense molecular packing in the crystal.

The highly efficient α- and vicinal bis-addition of cyclic imides to methyl propiolate in high yields and β-addition of these imides to α-imidoacrylates in quantitative yields is reported. These reactions offer a simple metal-free method for a gram-scale preparation of practically useful α-imidoacrylates and vicinal bisimides under mild conditions with high atom economy and selectivity.

A series of novel isonicotinoyl hydrazones based on pyridoxine (vitamin B6) were synthesized. The synthesized compounds were evaluated for their antimycobacterial activity on M. tuberculosis H37Rv strain. The most potent compound 13 showed good activity on H37Rv strain and on clinical isolates of M. tuberculosis with multidrug-resistant tuberculosis (TB) profile included first- and second-line drugs. Cytotoxicity studies of compound 13 on human embryonic kidney cells, human liver, human mesenchymal stem cells, and human embryonic lung cells in vitro demonstrated it is 2–3 times less toxicity then isoniazid and 1.5–2 less toxicity than ethambutol and moxifloxacin. Compound 13 showed weak complexation with Fe3+ ions, low acute toxicity (LD50 > 2000 mg/kg per os on mice) and the identical to isoniazid and significantly better than ethambutol and moxifloxacin efficacious in the mouse model of drug-sensitive (H37Rv) TB. These facts make him a promising candidate for future developments of antitubercular drugs.

By methods of cyclic voltammetry and preparative electrolysis, the electrochemical properties of sterically hindered imidazolium salt 3-(6-(1H-pyrazol-1-yl)pyridin-2-yl)-1-(2,6-diisopropylphenyl)-1H-imidazol-3-ium bromide containing the pyrazolyl-pyridyl moiety are studied and the N-heterocyclic carbene complexes of nickel(II) are electrochemically synthesized by the cathodic reduction of this salt in the presence of nickel(II) ions. The monitoring of this preparative electrosynthesis by mass spectrometric measurements demonstrates that these organonickel complexes can contain either one (when a diaphragm cell is used) or two (when the diaphragmless cell contains a soluble nickel anode) N-heterocyclic carbene ligands.

The Kukhtin–Ramirez reaction of 2-(3-oxo-3-phenyl)ethoxy-benzo[d]-1,3,2-dioxaphospholes with perfluorodiacetyl was monitored by NMR methods. To our surprise the initial stage involved a kinetically controlled [4+4]-cycloaddition with the formation of a cage phosphorane containing a 2′,5′,8′,9′-tetraoxa-2λ5-phosphaspiro[benzo[d][1,3,2]dioxaphosphole-2,1′-bicyclo[4.2.1]nonan]-3′-ene (compound 5) scaffold. Intermediate 5 then converts to spirophosphorane–4′,5′-bis(trifluoromethyl)-2λ5-spiro[benzo[d] [1,3,2]dioxaphosphole-2-yl-2,2′-[1,3,2] dioxaphosphole (compound 4). Compound 4 further rearranges into a cage phosphorane derivative containing a [2,5]epoxybenzo[d][1,3,6,2]trioxaphosphocine] (compound 3) backbone.

Bisphosphonium salt containing a 1,4-dihydroxynaphthyl-substituted moiety was synthesized in high yield by the reaction of 2-methyl-1,4-naphthoquinone with three equivalents of triphenylphosphine and hydrogen bromide. The structure of the synthesized bisphosphonium salt was determined by NMR spectroscopy and X-ray diffraction.

Elongation factor P (EF-P) is a translation protein factor that plays an important role in specialized translation of consecutive proline amino acid motifs. EF-P is an essential protein for cell fitness in native environmental conditions. It regulates synthesis of proteins involved in bacterial motility, environmental adaptation and bacterial virulence, thus making EF-P a potential drug target. In the present study, we determined the solution and crystal structure of EF-P from the pathogenic bacteria Staphylococcus aureus at 1.48 Å resolution. The structure can serve as a platform for structure-based drug design of novel antibiotics to combat the growing antibiotic resistance of S. aureus.

A one-pot method for the synthesis of dipotassium salts of N-alkyl-N-{[O-alkoxy(hydroxy)phosphoryl]methyl}dithiocarbamic acids has been elaborated. Dipotassium salts of N-isopropyl-, N-butyl-, and N-cyclohexyl-N-{[hydroxy(O-ethoxy)phosphoryl]methyl}dithiocarbamic acids as well as N-{[O-butoxy(hydroxy)phosphoryl]methyl}-N-(2-methoxyethyl)dithiocarbamic acid have been synthesized and isolated. Crystal and molecular structure of the latter compound have been elucidated.

The reaction of (R)-1-(1-phenyl)ethyl-3-(O,O-diethylthiophosphoryl)thiourea with Cu(II) acetate is accompanied by copper reduction and leads to the formation of a chiral polynuclear Cu6L6 complex. In the crystalline phase the complex consists of six Cu(I) ions alternating with sulfur atoms in the central core, with all six ligands exhibiting similar 1,5-S,S-coordination modes. This structural multinuclear arrangement is preserved in solutions, while at the same time partial disproportionation is observed with the formation of complexes of lower dimensionality. Synchronous redox processes are observed for all six copper ions in the complex in the solid state. The mechanism of copper reduction with the ligand itself as a reducing agent is proposed.

A family of helical dinuclear copper(I) pyridylphospholane complexes [Cu2L3X]X (X = BF4−, Cl− and Br−) was prepared. The family includes the first examples of this type of complex based on copper(I) chloride and copper(I) bromide. The two isomers typical of this class of compounds, namely head-to-head and head-to-tail complexes, were studied in solution by spectroscopic and optical methods, and in the solid state by X-ray diffraction. Furthermore, the solid-state luminescence of the complexes at different temperatures was studied, and the results were interpreted using quantum-chemical calculations. It was shown that the luminescence of the complexes is attributed to the 3(M + X)LCT transitions.

This article describes the design and biological properties of a BODIPY FL-labeled monoterpenoid BF2-meso-(4-((1″R)-6″,6″-dimethylbicyclo[3.1.1]hept-2″-ene-2″)yl-methoxycarbonylpropyl)-3,3′,5,5′-te...

Two new isomorphous ring-like hexanuclear symmetrical coordination species ((2-2H)232M6, M = Co, Ni) presenting a hollow cyclic structure were successfully designed through the molecular recognition between the in situ generated sulfonylcalix[4]arene (3) supported trinuclear clusters and flexible macrocyclic linkers based on the low rim appended calix[4]arene diacid derivative (2-4H) demonstrating a pincer-like shape. The obtained coordination compounds have been characterized from a structural point of view in the crystalline phase revealing the formation of internal hydrophobic voids, passing through the hexameric units, and external voids, resulting from the packing of the complexes in the lattice. A slight structural transformation was evidenced upon air-drying, leading to the closure of external voids caused by the solvent release and also the solvent mobility within the network. The ability of obtained desolvated solid-state hexanuclear species to uptake small volatile molecules like H2O, CH3C(O)CH3, MeOH and EtOH has been investigated by dynamic vapor sorption (DVS) showing their high affinity towards more polarizable molecules.

New thermally stable long-chained 2-alkylisothiuronium 7-chloro-4,6-dinitrobenzofuroxan-5-olates were obtained from the corresponding bromides and 5,7-dichloro-4,6-dinitrobenzofuroxan, the hydrolysis of the C(5)–Cl bond to produce phenolic function having occurred in the course of the process. The compound structure was determined by IR spectroscopy, elemental analysis and X-ray single crystal study. Salts with C14–C18 alkyl groups revealed moderate antibacterial and antifungal activities.

It has been shown for a wide range of epoxy compounds that their interaction with triphenylphosphonium triflate occurs with a high chemoselectivity and leads to the formation of (2-hydroxypropyl)triphenylphosphonium triflates 3 substituted in the 3-position with an alkoxy, alkylcarboxyl group, or halogen, which were isolated in a high yield. Using the methodology for the disclosure of epichlorohydrin with alcohols in the presence of boron trifluoride etherate, followed by the substitution of iodine for chlorine and treatment with triphenylphosphine, 2-hydroxypropyltriphenylphosphonium iodides 4 were also obtained. The molecular and supramolecular structure of the obtained phosphonium salts was established, and their high antitumor activity was revealed in relation to duodenal adenocarcinoma. The formation of liposomal systems based on phosphonium salt 3 and L-α-phosphatidylcholine (PC) was employed for improving the bioavailability and reducing the toxicity. They were produced by the thin film rehydration method and exhibited cytotoxic properties. This rational design of phosphonium salts 3 and 4 has promising potential of new vectors for targeted delivery into mitochondria of tumor cells.