Femtosecond quadratic nonlinear optical (NLO) activity of composite polymer materials (with chromophore load 25, 30 and 35 wt%) containing the quinoxalinone-based dye with Bn/Bz substituent in various positions of the framework have been studied by second harmonic generation technique. Four novel dipole chromophores have been synthesized and their linear optical and NLO properties were investigated by UV–Vis spectroscopy and DFT calculations, respectively. Values of NLO coefficient, d33, for poled thin films of PMMA-based composite materials reach 69–77 pm/V and they preserve 81–93% of initial NLO activity after 6 mouth of storage at ambient temperature.

Poled thin films of composite polymer materials based on PMMA doped with high thermally stable chromophores with the structure D-π-A1-π-A2 and D-π-A1A2 with a carbazole donor D, a quinoxalinone core, A1, either in a π-conjugated bridge or in a macroacceptor, were obtained. The effect of the chromophore structure on the values and long-term stability of the nonlinear optical coefficient, d33, of such thin films has been shown.

Dipole azinylmethylenemalononitrile-based chromophores with various fused azine (quinoline, quinoxaline and pyrido[2,3-b]pyrazine) moieties and bulky TBDPS-ethyl group in aniline donor fragment have been synthesized. Nonlinear optical (NLO) activity of poled PMMA films doped with such dyes has been investigated by second harmonic generation technique with in two approaches. Composite materials exhibit the growth of NLO performance at increasing dyes load from 25 wt% to 35 wt%. Polymer films doped with quinoxalin(on) ylmethylenemalononitrile-based chromophores demonstrate enhanced values of NLO coefficients, d33, up to 85 p.m./V.

The geometric parameters of the perylene substructure in fullerenes were analyzed and found to lie within the range characteristic of stable fullerenes, indicating that this substructure does not induce significant molecular strain. However, the small energy difference (10 kcal/mol) between the singlet and triplet states of perylene may contribute to fullerene instability, as the transition to the higher-symmetry triplet state (C2v) becomes favorable compared to the singlet state (C2). The closed-shell nature of perylene ensures that its geometric and electronic properties remain largely unchanged upon incorporation into fullerene frameworks. Three distinct configurations of perylene in fullerenes were identified: separated (no shared bonds), adjacent (shared bonds), and intercrossed (shared hexagons). Separated perylene exhibits a closed electron shell, while adjacent and intercrossed structures predominantly display open-shell characteristics. This finding was checked for the C78 fullerene, in which the structural distortions are most pronounced in hexagons with delocalized π-bonds. Given the prevalence of perylene in numerous fullerenes, these findings provide valuable insights into the structural and electronic factors influencing fullerene stability.

Unconventional luminescence caused by hindered intra- and intermolecular mobility of molecules is of great research interest in science and technology. However, the lack of data on the effect of the structure of such compounds on the process of aggregation-induced emission and the underdevelopment of existing synthetic approaches make these studies difficult. We have developed new non-classical luminophores based on amidophosphonate and amidophosphate containing polysilsesquioxanes obtained by a simple two-stage synthetic route: monomers were obtained by nucleophilic substitution reactions at the P(V) atom, and the corresponding polymers were obtained by hydrolytic polymerization. Luminescent properties of both monomers and polymers were described, and it was shown that luminescence by cluster aggregation is also characteristic of low-molecular luminophores.

Azo-functionalization of aniline-containing methacrylic copolymers yielded polymers with side-chain chromophore contents ranging from 4.4 to 39 mol%. The highest nonlinear optical coefficient was achieved with a chromophore content of 17 mol%. The resulting polymers demonstrated good relaxation stability at elevated temperatures: 98 and 86% at 55 and 65 degrees C, respectively.

Generally, the intermolecular H-bonding is a powerful type of interactions capable of playing dominating role in the self-assembly of extended molecular networks in the crystalline phase. Herein, we report on the first example of 1D supramolecular polymerization, supported by the intermolecular H-bonding involving the 3,5-dihalogenosalicylideneamine moieties, appended to 1.3-disubstituted calix[4]arene platform, and imposed exclusively by the crystal packing effect, which was elucidated primary by the X-ray diffraction study.

Femtosecond nonlinear optical activity of poled polymer films doped with novel D-π-A1-π-A2 chromophores (D = trisubstituted aniline, π = vinylene, A1 = quinoxalin-2-one, A2 = tricyanofuran; 25 and 30 wt

This work discusses the surface modification of Mn2+-containing silica nanoparticles (SNs) with an outer shell of denatured bovine serum albumin (BSA) as a means of reducing the levels of hemolytic and hemoagglutination activity that are characteristic of bare SNs. However, the formation of a BSA-based shell has a significant impact on the r1- and r2-relaxivity values of Mn2+ ions embedded in the SNs, with these changes increasing in line with the magnetic field strength, from 0.47 T to 7.0 T. Consequently, both the BSA-coated and the initial Mn2+-doped SNs are regarded as T1-weigthed contrast agents at 0.47 T, with the corresponding r2/r1 ratios falling within the range of 1.27-1.47. At 7.0 T, the r2/r1 ratio for Mn2+ ions in the initial SNs is 4.55, while for Mn2+ ions in BSA-coated SNs, the ratio is 9.55. The revealed patterns correlate with the known ability of BSA to bind manganese ions, which allows us to explain the observed trends by changes in the hydration of Mn2+ ions due to their partial movement from the nanoparticles to the BSA shell.

A series of new isatin hydrazones bearing phosphorus-containing moiety was synthesized through a simple, high-yield and easy work-up reaction of phosphine oxide (Phosenazide) or phosphinate (2-chloroethyl (4-(dimethylamino)phenyl)(2-hydrazinyl-2-oxoethyl)phosphinate, CAPAH) hydrazides with aryl-substituted isatins. The 31P NMR technique showed that, in most cases, out of 12 examples in solution, the ratio of the two spatial isomers varied from 1:1 to 1:3. Quantum chemical calculations confirmed the predominance of Z,syn form both in the gas phase and in solution. According to X-ray analysis data in crystals, they exist only in Z,syn form too. Most of the phosphine oxide derivatives and 5-methoxy- and 5-bromoaryl phosphinate analogs exhibit anti-aggregant activity at the level of acetylsalicylic acid but inhibit platelet activation processes more effectively. The 5-chloro type phosphinate derivative exhibits anti-aggregant properties more effectively than acetylsalicylic acid under the conditions of the tissue factor (TF)-activated thromboelastography (TEG) model, the ex vivo thrombosis model. Thus, all the obtained results can become the basis for future pharmaceutical developments to create effective anti-aggregation drugs with broad antithrombotic potential.

D-π-A chromophores based on novel macroacceptors − fused azinylmethylenemalononitriles (fused azine = pyrido[2,3-b]pyrazine, quinoline, quinoxaline and quinoxalin-2-one) − have been synthesized and their linear and nonlinear optical properties in gas, solution and in poled PMMA-based films have been investigated by DFT, UV-vis and second harmonic generation technique. The transition from chromophores with an azine acceptor to ones with azinylmethylenemalononitrile acceptors leads to a 10-fold increase in calculated μβ values. Poled polymer films doped with studied chromophores at 25wt% load exhibit quadratic nonlinear optical activity with d33 values up to 42 pm/V.

Two dinuclear double oxygen-bridged iron(III) complexes made of the Fe-2(mu(2)-OR)(2) diamond-core cluster resulting from the coordination between iron(III) cations with calix[4]arene ligands and bearing two lower-rim-appended salicylideneamine (4) or o-methoxy-salicylideneamine coordinating sites (5), connected to the macrocyclic platform via three methylene bridges and displaying a salen-type coordination pocket, were synthesized and characterized using single-crystal X-ray diffraction (SCXRD), powder X-ray diffraction (PXRD), high-resolution mass spectrometry (HRESI-MS), IR, TG-DSC and EA techniques. Independent of the presence of the o-methoxy group in the salicylideneamine moieties, the as-formed complexes contained two nonequivalent iron(III) atoms, both adopting a distorted octahedral coordination N2O4-environment but differing in the cis and trans positions of the nitrogen atoms within the metal coordination sphere, as attested by single-crystal X-ray diffraction and DFT-B3LYP calculations. The possible reason for the observed coordination mode of the macrocyclic ligands is their conformational behavior upon coordination with Fe(III) cations, as confirmed by DFT-B3LYP analysis. Fe-57 M & ouml;ssbauer spectroscopy study showed that both Fe(III) atoms were present in high spin states at room temperature and at 80 K in the studied coordination compounds. The methoxy groups located at the ortho position of the salicylideneamine coordinating fragments were observed to influence the energy of the frontier orbitals, resulting in an increase in the bandgap energy from 1.97 eV to 2.07 eV, as experimentally established by solid-state voltammetry study of 4(2)-Fe-2 exp and 5(2)-Fe-2 exp, respectively. The interplay between the steric and electronic factors, emerging from the o-methoxy group within coordinating salicylideneamine moieties, seemed to have a negligible effect on the electronic properties of the prepared clusters but significantly impacted the frontier orbital energy distribution, according to both experimental data and theoretical calculations.

Water-soluble ammonium salts were prepared by the reaction of new sterically hindered isatin derivatives with analogues of Girard's reagents. The resulting isatin-3-hydrazones exhibit high antimicrobial and antiaggregation activity with low hemotoxicity. The dependence of physiological activity on the volume of the benzyl substituent was established.

Lichens are symbiotic organisms that effectively survive in harsh environments, including arid regions. Maintaining viability with an almost complete loss of water and the rapid restoration of metabolism during rehydration distinguishes lichens from most eukaryotic organisms. The lichen Xanthoria parietina is known to have high stress tolerance, possessing diverse defense mechanisms, including the presence of the bright-orange pigment parietin. While several studies have demonstrated the photoprotective and antioxidant properties of this anthraquinone, the role of parietin in the tolerance of lichens to desiccation is not clear yet. Thalli, which are exposed to solar radiation and become bright orange, may require enhanced desiccation tolerance. Here, we showed differences in the anatomy of naturally pale and bright-orange thalli of X. parietina and visualized parietin crystals on the surface of the upper cortex. Parietin was extracted from bright-orange thalli by acetone rinsing and quantified using HPLC. Although acetone rinsing did not affect PSII activity, thalli without parietin had higher levels of lipid peroxidation and a lower membrane stability index in response to desiccation. Furthermore, highly pigmented thalli possess thicker cell walls and, according to thermogravimetric analysis, higher water-holding capacities than pale thalli. Thus, parietin may play a role in desiccation tolerance by stabilizing mycobiont membranes, providing an antioxidative defense, and changing the morphology of the upper cortex of X. parietina.

Nonlinear optical (NLO) activity of polymer materials doped with 30 and 40 wt% load of two novel thermally stable quinoxaline-based chromophores with bulky TBDPSO groups in donor fragments was studied by second harmonic generation technique. Poled thin polymer film with chromophore B containing five various bulky substituents demonstrates low d(33) values (14-19 pm/V). Oppositely, composite material with 30 wt% load of chromophore A, which does not contain bulky substituents in acceptor moiety, have shown enhanced NLO activity (up to 51 pm/V).

New macrocyclic Schiff bases, lower rim disubstituted imine derivatives of thia- and calix[4]arenes 7 and 8 adopted in a cone stereoisomeric conformation, bearing two tert-butyl substituents grafted to iminophenol coordinating sites, and containing a spacer composed of two methylene bridges were synthesized. The prepared compounds were characterized by a complex of physicochemical methods in solution (1H/13C NMR spectroscopy, MALDI TOF mass spectrometry) and in the crystalline phase (IR spectroscopy, single-crystal X-ray diffraction (XRD)). In crystals calix[4]arene 7 forms a solvate in which acetonitrile or methanol molecules are included into the macrocycle cavity, whereas the crystals of thiacalix[4]arene 8 contain no solvent molecules. The difference in the conformational behavior of the macrocyclic platform was evidenced when comparing the crystal structures of calix[4]arene 7 and thiacalix[4]arene 8. The stoichiometry and the logarithm and stability constant values of the corresponding complexes of the synthesized macrocyclic Schiff bases with 3d-metal cations (CoII, NiII) in solution were determined using spectrophotometry titration. When interacting with CoII cations, compound 7 forms complexes with stoichiometry Lig: M = 1: 1 and 1: 2 (Lig is ligand, and M is metal). In the case of compound 8, complexes with the stoichiometry Lig: M = 1: 4, as well as 1: 2, are observed, which presumably indicates the involvement of “soft” sulfur atoms in the interaction with the metal cations. The replacement of CoII cations by NiII resulted in the formation in the solution of complexes with the stoichiometry Lig: M = 2: 1, 1: 1 and Lig: M = 1: 1, 1: 2 for compounds 7 and 8, respectively.

New pharmacological compositions based on water-soluble pectin metal complexes PG-NaCaFe and PG-NaFeCoCu (PG is polygalacturonate) in weight ratios of 6: 1, 9: 1, and 12: 1 promising for pharmacology and medicine as drugs for the treatment of both iron deficiency and pernicious anemia are developed. According to the testing results on males of the Sprague Dawley rat line in vivo , the most pronounced increase in the number of erythrocytes and hematocrit is observed upon the introduction of the composition with the 9: 1 PG-NaCaFe to PG-NaFeCoCu weight ratio indicating the highest efficiency of this complex drug.

Formation of stable complexes of pectin polysaccharides with Nifedipine hypotensive drug has been shown by IR and UV spectroscopy, stereochemistry of the complexes has been determined, their preparation conditions have been optimized. Features of thermal decomposition of pectin and the prepared complexes with Nifedipine have been studied by TGA/DSC. Obtained results provide scientific foundation to design new water-soluble non-toxic formulation of Nifedipine to expand the use of the drug in medicine.

Impact of pi-deficient heterocyclic core (A') in conjugated bridge of D-p-A'-p-A chromophores (D = N,N-dihexylaniline, A = tricyanofuran derivative) on optical and thermal properties has been investigated. Three new chromophores with vinyl-hetaryl-vinyl bridges containing pi-deficient benzoazine moiety (quinoxaline, quinoxalinone and quinoline) have been synthesized along with new chromophores with vinyl-thiophene-vinyl bridge containing pi-excessive heterocycle and short vinylene bridge, and their properties are compared to reveal the role of pi-deficient hetaryl moiety. Their linear optical properties were systematically investigated by UV-Vis spectroscopy and molecular nonlinear optical (NLO) characteristics were predicted by DFT calculations. As the aromaticity of the heterocycle in the bridge increases, a hypochromicity and hypsochromic shift of the absorption maximum manifest themselves in the UV-Vis spectra, the origin of electron transitions was studied by TD-DFT with CAM-B3LYP and PBE0 density functionals. The calculated first hyperpolarizability, beta(tot), for A' = quinoxaline, quinoline and thiophene, was shown to be almost independent on the type of the p-bridge core, being in a narrow interval 800-831 center dot 10(-30) esu, while for A' = quinoxalinone beta(tot) is essentially higher (996 center dot 10(-30) esu). All chromophores exhibit good thermal stability (T-d > 192 degrees C). Thin films of composite polymer materials with PMMA matrix and studied chromophores as guests as well as of some molecular glasses were spin-cast and corona-poled, and their quadratic NLO activity was measured by two different techniques. For materials with guest chromophores containing quinoxalinone, quinoxaline and thiophene moieties in the bridges NLO coefficients d(33) were found to be rather close and reached 76 pm/V, what is almost 3 times higher than that for polymer film with quinoline-based chromophore. Rather high values of NLO coefficients for molecular glasses based on chromophores with quinoline, thiophene and quinoxalinone cores were obtained: 52, 124 and 132 pm/V, respectively, which notably exceed the values for composite materials with these chromophores as guests.

Novel D-π-A′-π-A chromophores with quinoxaline cores as auxiliary acceptors and various donor moieties (aniline, carbazole, phenothiazine, tetrahydroquinoline) containing bulky tert-butyldimethylsilyloxy (TBDMSO) groups and tricyanofuranyl (TCF) acceptors with bulky cyclohexylphenyl substituents were synthesized via eight- to nine-step procedures, and their photo-physical and thermal properties were investigated. The values of the chromophores’ first hyperpolarizabilities were calculated in the framework of DFT at the M06-2X/aug-cc-pVDZ computational level; the effect of the introduction of the TBDMSO group into the donor fragment is shown to be inessential, as this group is not coupled to the π-conjugated system of the chromophore. The chromophore with the tetrahydroquinoline donor has a first hyperpolarizability value of 937 × 10−30 esu, which is the highest for the studied chromophores. Atomistic modeling of composite materials with the studied chromophores as guests demonstrated that the presence of bulky substituent in the donor fragment prevents notable aggregation of chromophores, even at high chromophore content (40 wt.%). The nonlinear optical performance of guest–host materials with 25 and 40 wt.% of suggested chromophore content was studied using a second harmonic generation technique to give the NLO coefficient, d33 up to 52 pm/V.