A number of hypercrosslinked polystyrene networks are studied. The networks are obtained via additional crosslinking of granules of styrene copolymer with 0.5% divinylbenzene (0.3–0.5 mm) and microgranules with 1% divinylbenzene (3.5 µm) using monochlorodimethyl ether to densities of crosslinking from 60 to 500%. It is found that as the degree of crosslinking grows, the absorption in the electronic spectrum of the polymer extends to the visible region, and the granules change color (toward as dark as black); this phenomenon is much less expressed for microgranules and milled materials. For a consistent explanation of these two observations, assumptions are made about the appearance and increase in the contrast of density fluctuations of a tracery hypercrosslinked network and light scattering on such micro-inhomogeneities in the volume of particles of the compared series of polymers.

Using nuclear quadrupole resonance spectroscopy, it has been found that chloroform and dichloroethane absorbed by microporous hypercrosslinked polystyrene retain the capacity of the crystalline structure formation in small free spaces of the network on cooling, whereas p-dichlorobenzene demonstrates the complete loss of the capacity of crystallization.

The aqueous solutions of Bashkir floral honey of wild and domesticated bees were studied with high-resolution 1H and 13C NMR and nuclear magnetic relaxation. NMR was shown to provide only qualitative data on the composition of the studied honey samples. Data on the composition of the minor components (amino acids), as well as the mobility of water protons in honey, indicate that the distinctions between honey from wild and domesticated bees are due to both the honey composition and the difference in the interactions of components with one another and with water.

N -Acryloyl derivatives of histamine, monoethanolamine, and β-alanine, which contain imidazole, hydroxyl, and carboxyl functional groups, respectively, are synthesized and characterized. Copolymers, which are further divided into thermally precipitable and thermally nonprecipitable (soluble) fractions, are obtained via the free-radical copolymerization of N -vinylcaprolactam and the specified comonomers that is initiated by a persulfate–tertiary amine redox system in a medium of 10% aqueous dimethyl sulfoxide (DMSO) at 65°C. It is shown that the soluble fractions of the synthesized copolymers exhibit catalytic activity in the reaction of hydrolysis of 4-nitrophenyl propionate (NPP) at a temperature above the coil-to-globule transition.

Dynamic properties of the water filling of the internal space of hypercrosslinked polystyrene networks are studied via NMR cryoporometry, spin relaxation, and diffusometry. It is found that in the temperature range of 210–240 K, where frozen water melts in the thin pores of the polymer and seems to become a viscous liquid, the main type of molecular motion is rotational and the main relaxation mechanism (T 1) is spin-rotational interaction between protons. Above 240 K, dipole-dipole coupling is shown to become the main relaxation mechanism T 1. In the temperature range of 210–295 K, the hypercrosslinked polystyrene matrix displays a set of water spin-spin relaxation rates that suggest the structure has cavities (pores) with different sizes and different conditions for the molecular motion of water. We conclude that the shorter (tens of ms) relaxation times T 1 and T 2 of water in the polymer at the temperature above 265 K compared to free water (2–3 s) indicate features of the dynamic characteristics of water in hydrophobic pores (or thin films on the surfaces of granules) that differ from those of free water. The tortuosity coefficients of the water’s path of molecular motion are found to change in a symbate manner with a change in the water content in the hypercrosslinked network.

The paramagnetic chemical shifts in the 1H and 13C NMR spectra of lanthanide complexes (Ln = Eu, Yb, and Pr) with diethylenetriaminepentaacetic acid were analyzed. It was demonstrated that Eu+3 in aqueous solution can coordinate to one of the carboxylate groups in a chelating bidendate fashion through two O atoms.

A simple method for the preparation of colloidal catalysts of the aerobic oxidation of glucose, viz., metal polymeric complexes of gold or its alloy with silver, as well as complexes containing glucose oxidase, was developed. The complexes containing glucose oxidase were synthesized by the covalent immobilization of enzyme in aqueous medium (in the absence of toxic chemicals and solvents) on the shell of the alternate maleic acid copolymer covering a core made of nanogold or its alloy. The catalysts obtained were studied by transmission electron microscopy, spectrophotometry, IR spectroscopy, and light scattering. All the catalysts were active and selective in the process of the aerobic oxidation of glucose to gluconic acid (H2O2 registration method), whereas the catalytic activity of glucose oxidase was 73–96% (relative to the introduced enzyme). The highest activity was found for the colloidal catalysts containing gold and silver alloy in the core at pH 9.0 and T = 50 °C (registration of glucose and gluconic acid by 1H NMR). 1H NMR spectroscopy was used for the first time for the registration of glucose and gluconic acid in such reactions.

Crystalline complex fluoroantimonates(III) with amino acids (glycine, β-alanine, DL-serine, DL-valine, L-leucine, and L-phenylalanine) have been prepared. The complexes stability in aqueous solutions has been studied with the cementation method. 1 H NMR studies of aqueous solutions of the amino acids complexes with SbF 3 at pH 1–6 and room temperature are reported. Preparation of polycrystalline metal antimony in aqueous solutions of tetrafluoroantimonates(III) complexes with the protonated amino acids has been demonstrated.

The distribution of iodine-125 labeled human alpha-fetoprotein in mice was studied after its intravenous injection. The maximal accumulation of alpha-fetoprotein in different tissues and organs of animals was observed mainly 5 hours after injection. Then the protein was gradually eliminated from the body. In the liver, intestine and blood of intact animals 125I-alpha-fetoprotein persists for at least three days. Accumulation of alpha-fetoprotein in various tissues and organs may determine the different biological effects of this protein. In the mice with transplanted lymphatic leukemia cells P388 the high level of alpha-fetoprotein accumulation was detected in the tumor tissue, reaching 6% of the injected amount per 1 g of tissue. This allows considering the radionuclide-labeled alpha-fetoprotein as a promising medical radionuclide marker for the radiological detection of malignant tumors.

The melting of water frozen preliminarily at 180 K in a free internal volume of water-swollen hypercrosslinked polystyrene networks with degrees of crosslinking ranging from 43 to 500% is studied by NMR. It is found that ice melts within a narrow range of low temperatures, 195–225 K, demonstrating that the pores in the networks are small and uniform in size. It is, however, impossible to calculate the pore size via the Gibbs-Thomson equation, since the structure of water (and hence its properties) depend on a sample’s rate of freezing. We conclude that the activation of the orientational motions of water molecules starts to manifest itself already at 200 K; upon reaching 220–230 K, the total mobility of water molecules is due largely to translational motions with an activation energy of 27–28 kJ/mol.

A new method is developed for the synthesis of branched and network polymers that give rise to poly(epoxy isocyanurate) matrices during thermal curing. Matrix polymers are prepared on the basis of polyethers (poly(propylene glycol) or poly(tetramethylene glycol)), diisocyanate, and an epoxy oligomer. The chemistry of formation of networks is studied by NMR and IR spectroscopy. Formation of structures with different topologies is analyzed, and optimum conditions for the formation of gradient networks that are complex structural organizations are ascertained. It is shown that, during microphase separation of a three-component system whose components differ appreciably in surface energy and other parameters, the composition of microphases may be estimated. Optimum conditions of the curing process that provide formation of the perfect structure of networks are found, and their chemical structure is investigated.

Fluorescent probe CAPIDAN (or "K-35"), N-(p-carboxyphenyl)imide of 4-(dimethylamino)naphthalic acid, is used as a detector of structural changes in human serum albumin in some diseases. In these cases observed changes in its fluorescence can be used to predict disease severity, stage, or outcome as good as or better than routine diagnostic tests.In this work, some aspects of probe's interaction with albumin molecule were studied using optical methods, NMR and computer simulations. It was shown that probe's fluorescence originates mostly from molecules bound to the drug-binding site I. It is suppressed by phenylbuthazone, a marker for this site. H-1 NMR data shows that the aromatic part of CAPIDAN, including its amino group, is immersed into protein. Sensitivity of the interaction to the ionic strength of solution suggests that CAPIDAN's negatively charged carboxyl group localizes at the site/solution interface, near exposed positively charged residues.Positions of the peaks of CAPIDAN's absorption/excitation spectra indicate polar environment around the bound probe and suggests the existence of water molecules entrapped in the pocket. Limited Stokes shift of the fluorescence spectrum and H-1 NMR data provide evidence of hindered motion of bound probe, pocket's polar groups and entrapped water molecules. (C) 2012 Elsevier B.V. All rights reserved.