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Herein we present the regio- and diastereoselective synthesis of novel pyrrolidine-fused spiro-dihydrophosphacoumarins via intermolecular [3 + 2] cycloaddition reaction. The presented approach is complementary to existing ones and provides an easy entry to the otherwise inaccessible derivatives. Additionally, the unprecedented pathway of the reaction of 4-hydroxycoumarin with azomethine ylides is described. The anti-cancer activity of the obtained compounds was tested in vitro, the most potent compound being 2.6-fold more active against the HuTu 80 cell line than the reference 5-fluorouracil, with a selectivity index > 32.

It is well-known that non-IPR fullerenes are highly unstable. For this reason, they cannot be obtained as pristine fullerenes; however, some of them become stable as derivatives (exohedral or endohedral). In this article, we attempted to elucidate in detail molecular structure for such a non-IPR fullerene. Using theoretical approach supported by DFT calculations, the features of molecular structure of isomer 17894 (C1) of fullerene C76 with data about distribution of single, double and delocalized π-bonds as well its structural formula has been determined for the first time. The instability of the studied fullerene molecule caused by its open-shell structure and significant local overstrains related to the high folding angle value of pentagons in pentalene fragment. The supposed synthesis of the endohedral molecule starts with the ionic pair formation, i.e. anionic fragment of fullerene cage and metal cation electrostatically bound with it. It would lead to closing of open electron shell of fullerene and local overstrain release at pentalene fragment. As to the exohedral derivatives the probable positions of addends are discussed. Both methods in their own demonstrate the possibilities to stabilize the molecule of the C76 isomer 17894. The elucidation and analysis of structural features along with electronic characteristics of non-IPR fullerene molecules appear to be useful for predicting the possibility of their synthesis as derivatives and will assist in determination of their reactivity. This will ensure the targeted production of fullerenes and their derivatives for the needs of medicine, electronics and other industries. The fundamental knowledge of the properties of nanoobjects, namely fullerenes, is actually developing as the independent direction with a long-term perspective.

This review describes the most significant published results devoted to the study of the nature of the higher fullerenes stability, revealing of correlations between the structural features of higher fullerene molecules and the possibility of their producing. A formalization of the substructure approach to assessing the stability of higher fullerenes is proposed, which is based on a detailed analysis of the main structural features of fullerene molecules. The developed substructure approach, together with the stability of the substructures constituting the fullerene molecule, helps to understand deeper the features of the electronic structure of fullerenes.

It is well-known that the small non-IPR fullerenes Cn (n

A series of novel 4-aminobenzofuroxan derivatives containing aromatic/aliphatic amines fragments was achieved via aromatic nucleophilic substitution reaction of 4,6-dichloro-5-nitrobenzofuroxan. The quantum chemistry calculations were performed to identify the factors affecting the regioselectivity of the reaction. The formation of 4-substituted isomer is favored both by its greater stability and the lower activation barrier. Antimicrobial activity of the obtained compounds has been evaluated and some of them were found to suppress effectively bacterial biofilm growth. Fungistatic activity of 4-aminobenzofuroxans were tested on two genetically distinct isolates of M. nivale. The effect of some benzofuroxan derivatives is likely to be more universal against different varieties of M. nivale compared with benzimidazole and carbendazim. Additionally, their anti-cancer activity in vitro has been tested. 4-aminofuroxans possessing aniline moiety showed a high selectivity towards MCF-7 and M-HeLa tumor cell lines. Moreover, they exhibit a significantly lower toxicity towards normal liver cells compared to Doxorubicin and Tamoxifen. Thus, benzofuroxans containing aromatic amines fragments in their structure are promising candidates for further development both as anti-cancer and anti-microbial agents.

It is well-known that the small non-IPR fullerenes C

Two chromophores with π-deficient quinoxaline (Q) core in the π-electron bridge together with dibutylaniline (DBA) donor moiety and tricyanofuranyl (TCF) or dicyanovinyl (DCV) acceptor moieties have been synthesized to investigate their macroscopic nonlinear optical (NLO) activity in guest-host materials. A distinctive feature of the 7-DBA-VQPhV-TCF chromophore is predominance of negative solvatochromism over the positive one, which is quite rarely met for the chromophores manifesting inverse solvatochromic behavior as well as the blue shift of the absorption maximum compared to the chromophore FTC with divinylthiophene π-bridge. Introduction of quinoxaline moiety in the conjugated bridge promotes the increase of thermal stability: Td of both compounds is higher than 225 °C. Density functional theory was used to calculate the chromophores first hyperpolarizability (β). Quadratic NLO response characterized by d33 coefficient was measured by SHG technique for thin guest-host polymer films. The influence of chromophore content on the NLO coefficient of 7-DBA-VQPhV-TCF/PMMA film has been investigated and the d33 value of this film reaches 108 pm/V at 25 wt% load. The poled film 7-DBA-VQPh-DCV/PMMA shows twice smaller d33 values (30 pm/V) at the same chromophore load (20 wt%).

For the first time the nonlinear optical (NLO) activity of indolizine-based push-pull chromophores with different acceptor moieties was studied and compared. All the chromophores demonstrate strong absorption band in the visible (orange-red) part of the spectrum, with e of ca. 105 L∙cm−1∙M−1 notably dependent on medium polarity. Replacement of Ph-TCF acceptor by Hex-TCP one results in twofold increase of the first hyperpolarizability value. Energy gaps estimated by electrochemical methods decrease in the series ΔE1a,b>ΔE3a,b>ΔE2a,b for compounds with Ph-TCF, DCM and Hex-TCP acceptors, respectively, good agreement with DFT estimations is obtained. The nonlinear optical coefficient for poled PMMA-based films, containing 20 wt% of isomeric indolizine chromophores with weaker dicyanomethylene (DCM) acceptor and with π- bridge expanded by isophorone moiety, achieves 36 pm/V, thus exceeding those for materials containing chromophores with stronger Ph-TCF or Hex-TCP acceptors and with short vinylene π-bridge.

Fabrication of multifunctioning systems using noncovalent self-assembly principles are of great importance in biomimetic drug and gene delivery systems construction. Herein, supramolecular systems based on homologous series of amphiphiles bearing imidazolium fragment (C n H 2n+1 Im + Br − , where n = 14, 16, 18) have been fabricated and studied. Their aggregation behavior, solubilization activity toward hydrophobic guest, interaction with DNA decamer as well as integration with lipid bilayer have been investigated. Elongation of hydrophobic fragment by two methylene groups results in 4-fold decrease of critical micelle concentration, however does not affect solubilization properties. Examination of capability of amphiphiles studied to interact with DNA decamer have revealed some unconventional features: size and charge characteristics of amphiphile/oligonucleotide complexes do not depend on the length of hydrophobic tail, but the latter affects the efficacy of component binding, which achieves 100% for all amphiphiles. Capability of amphiphiles studied to integrate with lipid bilayer strongly depends on the length of hydrophobic fragment: the lower homologue C 14 H 29 Im + Br − increases the permeability of lipid bilayer, while the higher homologues C 16 H 33 Im + Br − and C 18 H 37 Im + Br − , vice versa, stabilize it. Enhance of capability of the drug (indometacin) to penetrate through lipid bilayer has been shown in the presence of C 14 H 29 Im + Br − .

Fifteen open-shell isomers off the forty six IPR isomers of fullerene C90 were found and investigated: 5 (Cs), 7 (C1), 9 (C1), 10 (Cs), 11 (C1), 20 (C1), 21 (C1), 22 (C1), 23 (C2), 24 (C1), 25 (C2v), 41 (C2), 42 (C2), 43 (C2), and 44 (C2). According to developed by us approach the positions of single, double, and delocalized π-bonds in the molecules of these isomers are shown for the first time. The obtained results of electronic and geometrical structures are fully supported by DFT method with the B3LYP functional at the 6–31G and 6–31G* levels. Molecules of these open-shell isomers contain different radical substructures (mainly the phenalenyl-radical substructures), they should be unstable and could not be obtained as empty molecules. Nevertheless, there is a possibility of obtaining them in polymeric forms or as endohedral or exohedral derivatives.

The purposeful change of crystallization conditions for rac-3-chloro-5-hydroxy-1-(4-methylbenzyl)-4-[(4-methylphenyl)sulfanyl]-1,5-dihydro-2H-pyrrol-2-one 1 leads to two different crystal modifications, namely, a racemic compound in the triclinic space group P with Z′ = 1 (α-1) and a partial solid solution based on a racemic compound in the monoclinic space group P21 with Z′ = 4 (β-1). The first modification, α-1, is characterized by a higher density of the molecular packing in the crystal, while the second one, β-1, by a stronger system of hydrogen bonds and the presence of positional and substitutional disorder simultaneously. The analysis of the crystal structure of modifications α and β allowed us to define some structural aspects of the partial solid solution formation. Namely, the tendency to build a stronger hydrogen bond system enables the solution of enantiomers of 1 to be formed in the crystalline phase, whereas the propensity of the molecules to adopt a more favorable transoid conformation limits the solubility of the minor enantiomer.

New stable water-soluble metal complexes of citrus pectin (sodium polygalacturonate, PG-Na) with biogenic microelements (Ca and Fe) that we synthesized were characterized by infrared spectroscopy, dynamic light scattering, and atomic force microscopy. The temperature dependence of the mass of PG-Na, PG-NaFe, and PG-NaFeCa samples was studied by simultaneous thermal analysis. Water was found to be the major component of the gas phase in the first stage of mass loss of PG-NaFe and PG-NaFeCa, while the second stage involves decarboxylation and decomposition. The stimulating action of PG-NaFe and PG-NaFeCa on hematopoiesis in outbred rats during growing period, manifested as more than 10% increase in the hemoglobin concentration, was demonstrated.

Achieving high thermal stability and control of supramolecular organization of functional dyes in sensors and nonlinear optics remains a demanding task. This study was aimed at the evaluation of thermal behavior and Langmuir monolayer characteristics of topologically varied nitrothiacalixarene multichromophores and phenol monomers. A nitration/azo coupling alkylation synthetic route towards partially O-substituted nitrothiacalixarenes and 4-nitrophenylazo-thiacalixarenes was proposed and realized. Nuclear magnetic resonance (NMR) spectroscopy and X-ray diffractometry of disubstituted nitrothiacalix[4]arene revealed a rare 1,2-alternate conformation. A synchronous thermal analysis indicated higher decomposition temperatures of nitrothiacalixarene macrocycles as compared with monomers. Through surface pressure/potential-molecular area measurements, nitrothiacalixarenes were shown to form Langmuir monolayers at the air&ndash, water interface and, through atomic force microscopy (AFM) technique, Langmuir&ndash, Blodgett (LB) films on solid substrates. Reflection-absorption spectroscopy of monolayers and electronic absorption spectroscopy of LB films of nitrothiacalixarenes recorded a red-shifted band (290 nm) with a transition from chloroform, indicative of solvatochromism. Additionally, shoulder band at 360 nm was attributed to aggregation and supported by gas-phase density functional theory (DFT) calculations and dynamic light scattering (DLS) analysis in chloroform&ndash, methanol solvent in the case of monoalkylated calixarene 3. Excellent thermal stability and monolayer formation of nitrothiacalixarenes suggest their potential as functional dyes.

Two isomeric indolizine-based chromophores (MPI-1)-OT-TCF and (MPI-3)-OT-TCF with octatetraene π-bridge and tricyanofuran acceptor moieties have been synthesized and systematically investigated. Chromophores exist as a mixture of E- and Z-isomers in low-polar dioxane and chloroform solutions, while in polar solvents only one isomer is observed. The chromophores show excellent thermal stability with Td>260 °C (DSC) and small energy gap between the frontier orbitals (about 0.8–0.9 eV) established by DPV method. The chromophores exhibit absorption in the visible and near IR region. Solvatochromic shifts amounting to ca. 100 nm when passing from dioxane to DMSO solutions are accompanied by appearance of an additional narrow intensive absorption band at ca. 915–950 nm resulting from the cross of cyanine limit. For the first time electro-optic activity of composite materials doped by indolizine based chromophores have been investigated; EO coefficient of poled (MPI-3)-OT-TCF/PMMA film afforded value of 29 pm/V at 10 wt% load.

The analysis of previously experimentally obtained and characterized by X-ray perfluoralkyl derivatives C74(D3h)(CF3)12 and C76(Td)(CF3)12 have shown for the first time that the most feasible positions of addends are phenalenyl-radical substructures and/or hexagons with delocalized pi-bonds, that lead to stabilization of these molecules. The most probable addition positions of H• and CF3• radicals to the «missing» fullerenes С74 (D3h) and С76 (Td) are revealed on the basis of developed approach of molecular modeling followed by DFT calculations. Radical addition reactions seem to be useful for stabilization of open-shell fullerenes.

All nine isolated-pentagon-rule isomers of fullerene C(82) were investigated by the DFT method with the B3LYP functional at the 6-31G, 6-31G*, and 6-31+G* levels. The distribution of single, double, and delocalized π-bonds in the molecules of these isomers is shown for the first time. The obtained results are fully supported by DFT quantum-chemical calculations of electronic and geometrical structures of these isomers. The molecules of isomers 7 (C(3v)), 8 (C(3v)), and 9 (C(2v)) contain some radical substructures (such as the phenalenyl-radical substructure), which indicates that they are unstable and cannot be obtained as empty molecules. Thus, there is a possibility of obtaining them only as endohedral metallofullerenes or exohedral derivatives. Isomers 1 (C(2)), 2 (C(s)), 4 (C(s)), 5 (C(2)), and 6 (C(s)) with closed electronic shell are supposed to be stable, resembling isomer 3 (C(2)), which has just been extracted experimentally as an empty fullerene. We assume they can be produced as empty molecules.