Vitamin K1 distribution following intravenous vitamin K1–fat emulsion administration in rats

This study investigated vitamin K₁ (VK₁) distribution following intravenous vitamin K₁–fat emulsion (VK₁–FE) administration and compared it with that after VK₁ injection. Rats were intravenously injected with VK₁–FE or VK₁. The organ and tissue VK₁ concentrations were determined using high‐performance liquid chromatography method at 0.5, 2 and 4 h to determine distribution, equilibrium and elimination phases, respectively. In the VK₁–FE group, the plasma, heart and spleen VK₁ concentrations decreased over time. However, other organs like liver, lung, kidney, muscle and testis, reached peak VK₁ concentrations at 2 h. In the VK₁ injection group, the liver VK₁ concentrations were significantly higher than those in other organs at the three time points. However, VK₁ concentrations in the other organs peaked at 2 h. In addition, in VK₁–FE group, the heart, spleen and lung VK₁ concentrations were significantly higher than those in the VK₁ injection group at the three time points, and the liver VK₁ concentration was significantly higher than that in the VK₁ injection group at 4 h. The VK₁ amount was greatest in the liver compared with the other organs. Thus, the liver is the primary organ for VK₁ distribution. The distribution of VK₁ is more rapid when injected as VK₁–FE than as VK₁. Copyright © 2015 John Wiley & Sons, Ltd.     

Über Fluoride des zweiwertigen Eisens: Cs7Fe4F15

Concerning the Cleavage of Si? C Bonds in Si-methylated Carbosilanes The chances for the cleavage of Si? Me bonds (Me ? CH₃) and Si? C? Si bonds in their molecular skeletons using ICl or ICl/AlBr₃ are examined in 13 carbosilanes; i. e. (Me₂Si? CH₂)₃ 1 , 1,3,5,7-tetramethyl-1,3,5,7-tetrasilaadamantane 2 , (Me₃Si? CH₂)₂SiMe₂ 3 , HC(SiMe₃)₃ 4 , the 1,3,5,7-tetrasilaadamantane. carrying bhe ? CH₂? SiMe, group at one Si atom 5 , the 1,3,5-trisilacyclohexane, carrying the ? CH₂? SiNe₃ group 6 , three derivatives of the 1,3,5-trisilacyclohexane, carrying SiMe₃ groups at skeletal C atoms 7 , 8 , 9 , three derivatives of the 1,3,5-trisilacyclohexane, carrying CH₃, groups at skeletal C atoms 10 10, 11 , 12 and 13 , derived from (Me₂Si? CH₂)₃ having one ?CBr₂ group. Using ICl one Me group at each Si atom in 1 can be split off successively, finally yielding (ClMeSi? CH₂)₃. 2 is transformed to the Si-chlorinated 1,3,5,7-tetrasilaadamantane. 3 , treated with ICl yields (ClMeSi? CH₂)₂SiMeCl, as 4 forms HC(SiMe₂Cl)₃. Higher chlorinated compounds can be obtained by using ICl and AlBr₃ in catalytic amounts. Thus 1 leads to (Cl₂Si? CH₂)₃, no ring-opening is observed. However, in the reaction of 1 with HBr/AlBr₃ bromination at the Si atoms and ring-opening (ratio 1:1) proceed coincidently. The reaction of either 3 or (ClMe₂Si? CH₂)₂SiMeCl with ICl/AlBr₃ leads to (Cl₂MeSi? CH₂)₂SiCl₂, and (Me₃Si)₂CH₃ forms (Cl₂MeSi? )₂CH₂ similarly. The ? CH₂? SiMe₃ group in 5 and 6 is not cleaved off by ICl; the introduction of a Cl group at each Si atom is observed instead. Furthermore, 6 undergoes cleavage (≈8%) of the Si? C ring adjacent to the chain-substituted Si atom [formation of ClMe₂Si? (CH₂? SiMeCl)₂CH₂? SiMe₂? CH₂Cl]. 7 , 8 , 9 (having the ? SiMe₃ group at the C atoms) react with ICl by splitting off one Si? Me group from each Si atom. In 7 we also observe the ring-opening to an amount of ≈25% [formation of (ClMe₂Si)CH₂? SiMeCl? CH₂? SiMe₂? CH₂Cl]. In ₈ (having two CH(SiMe₃) groups the ring-opening reaction is reduced to about 5% [formation of ClMe₂? CH(SiMe₂Cl)? SiMeCl? CH(SiMe₂Cl)? SiMe₂? CH₂Cl], while in 9 (having three CH(SiMe₃) groups) it is not found at all. In 10 , 11 , 12 (having the CH₃ group at the C atoms) ICl substitutes one Me group (formation of SiCl) at each Si atom (no ring-opening). The CBr₂ group reduces the reactivity of 13 towards ICl. Only the split-off of one Me group at the Si atom in para-position to the CBr₂ group is observed. Using ICl/AlBr₃ higher chlorinated derivatives are obtained (no ring-opening). Most of the mentioned compounds were identified via their Si? H-containing derivatives, thus facilitating the chromatographic separation as well as the ¹H-NMR-spectroscopic investigations.     

Theoretical and experimental infrared spectra of hydrated and dehydrated Nafion

The time‐dependent IR spectra during dehydration of fully hydrated Nafion show the reversible disappearance of the 1061 cm^?1 and 969 cm^?1 concurrent with the emergence of peaks at ～928 cm^?1 and ～1408 cm^?1. The first pair of group modes is associated with a dissociated exchange group (sulfonate) with a local C_3V symmetry. The C_3V group modes shift with state‐of‐hydration: The 969 cm^?1 peak completely vanishes and the 1061 cm^?1 is reduced to a small shoulder at 1070 cm^?1 at end of dehydration. The C_3V group modes are replaced by the pair of group modes of an associated exchange group (sulfonic acid) with C₁ local symmetry. The density functional theory normal mode analysis confirms that the sulfonic acid/sulfonate site plays a dominant role in the C₁ and C_3V group modes, respectively. This work clarifies the importance of assigning fluoropolymers peaks as group modes rather than traditional single functional group assignments as is often the case with the ～1061 cm^?1 and ～969 cm^?1 C_3V group modes. © 2013 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2013 , 51, 1329–1334     

Epoxidation of phosphinoyl alkenes with hydrogen peroxide

The epoxidation of alkenylphosphorus compounds with hydrogen peroxide was systematically studied, revealing that while alkenylphosphine oxides failed to produce the corresponding epoxides, alkenylphosphonates, or phosphinates having a phenyl group at α-position reacted with H₂O₂/K₂CO₃ or alkenylphosphonic acids or phosphinic acids having an aliphatic group at α- or β-positions reacted with H₂O₂/Na₂WO₄/Et₃N to produce high yields of the corresponding epoxides.     

Direct ethoxycarbonyldifluoromethylation of aromatic compounds using Fenton reagent

Direct ethoxycarbonyldifluoromethylation of aromatic compounds by BrCF₂CO₂Et was investigated using Fenton reagent in dimethylsulfoxide. Various five-membered hetero-aromatic compounds, benzene derivatives and uracil having ethoxycarbonyldifluoromethyl group were obtained catalytically with the combination of ferrocene and H₂O₂ at room temperature. The ethoxycarbonyldifluoromethylation occurred at the position predicted by the trend of the electrophilic substitution of aromatic compounds. When para-substituted aniline derivatives were used as a substrate, the one-pot synthesis of 3,3-difluoro-2,3-dihydroindole-2-one derivatives was achieved through the ethoxycarbonyldifluoromethylation at the ortho-position to the amino group and the consecutive intramolecular amidation of the amino group and the adjacent ethoxycarbonyldifluoromethyl group.     

CO2 capture capacity of five- and six-membered cyclic amidines bearing silatranyl group under dry conditions

CO₂ capture and release behaviors of three amidines bearing silatranyl group in DMSO solution were evaluated under dry conditions containing a very small amount of water. A six-membered cyclic amidine with silatranyl group captured CO₂ at 25 °C under atmospheric pressure quantitatively, and the trapped CO₂ was released at 60 °C under Ar atmosphere. A five-membered cyclic amidine with silatranyl group also captured CO₂, but less efficiently, under the same conditions as above. In contrast, an acyclic amidine with silatranyl group did not capture CO₂ at all, as expected from the poor CO₂-capturing ability of the acyclic amidine moiety.     

Two reversible enantiotropic phase transitions in a pentacoordinate silicon complex with an O,N,O′‐tridentate valinate ligand

Dimethyl[N‐(4‐oxidopent‐3‐en‐2‐ylidene)valinato‐κ³O,N,O′]silicon(IV), C₁₂H₂₁NO₃Si, (II), crystallizes in the orthorhombic space group P2₁2₁2₁. The chiral compound undergoes two sharp enantiotropic phase transitions upon cooling. The first transformation occurs at 163 K to yield a unit cell with one axis having double length. This intermediate‐temperature form has the monoclinic space group P2₁. The second transition takes place at 142 K and converts the single crystal into the low‐temperature form in the orthorhombic space group P2₁2₁2₁. This transition proceeds under tripling of the a axis of the high‐temperature form. Both phase transitions are fully reversible and correspond to order–disorder transitions of the isopropyl group of the valine unit in the ligand backbone. The phase transitions presented here raise questions, since they do not fit into the rules of group–subgroup relationships.     

Pulmonary toxicity of indium arsenide and arsenic selenide following repeated intratracheal instillations to the lungs of hamsters

Chronic toxicity of indium arsenide (InAs) and arsenic selenide (As₂Se₃) was studied in male Syrian golden hamsters which received InAs or As₂Se₃ particles, each containing a total dose of 7.5 mg of arsenic, by intratracheal instillations once a week for 15 weeks. As a control, hamsters were treated with the vehicle, phosphate buffer solution. During their total lifespan, the cumulative body weight gain of the hamsters in the InAs group was suppressed significantly compared with that in the control group, but not in the As₂Se₃ group when compared with that in the control group. However, the survival rate for the InAs group was significantly higher compared with the control group, but not for the As₂Se₃ group when compared with the control group. During the animals' total lifespan, one lung adenoma was seen in the 27 hamsters in the InAs group and one lung adenoma in the 23 hamsters in the control group. No tumors of the lung were observed in the As₂Se₃ group. Malignant tumors outside the lung appeared in four hamsters in the InAs group and in two in the As₂Se₃ group. No non-lung malignant tumours were seen in the control group. Total tumor incidence rates were 25.9% (7/27) in the InAs group, 10.3% (3/29) in the As₂Se₃ group and 8.7% (2/23) in the control group. There were therefore no significant differences in tumor incidence between the InAs or the As₂Se₃ group, and the control group. Regarding histopathological findings in the lung, incidence rates of proteinosis-like lesions, pneumonia, metaplastic ossification and emphysema were seen only in the InAs group, and alveolar or bronchiolar cell hyperplasia observed in both the InAs and the As₂Se₃ groups were at significantly higher rates than those in the control group. From these results, it was concluded that InAs and As₂Se₃ particles could induce pulmonary toxicity when instilled intratracheally into hamsters. A great deal of attention should be paid to the toxicity of both InAs and As₂Se₃, even though in this study the adverse health effects of As₂Se₃ appeared to be less than those of InAs.     

Darstellung,Kristallstruktur und schwingungsspektroskopische Untersuchung von Cs2Ba2(CO3)3

Preparation, Crystal Structure Determination, and Vibrational Spectroscopy on Cs₂Ba₂(CO₃)₃ A new alkali metal alkaline earth metal double carbonate, Cs₂Ba₂(CO₃)₃, was obtained by the reaction of cesium carbonate and barium oxalate in the solid state using elevated pressure (2.026GPa). It has been characterized by single X-ray diffraction: 1162 diffractometer data, space group I2₁3, a = 10.349(2) Å; Z = 4; R_w = 0.026. The internal vibrations of the carbonate group exhibit unusually pronounced splittings caused by crystal field effects. All vibrational absorptions in the IR spectrum as to be expected at the level of the factor group approximation have been observed at recording the IR spectrum at low temperatures (?196°C).     

A Potentiometric Study of the AgI Complexes of Some Sulphur Containing Amino Acids

The complex formation of silver(I) with some sulphur-containing amino acids was studied in aqueous solution by simultaneous pH and pM measurements at 25°C and at an ionic strength of 0.5M (K)NO₃. In acid medium complex formation occurs only through the thioether group and the carboxylate group is not involved. In alkaline medium both the thioether and the amino group are bound in either the tetrahedral AgL and AgL₂^? chelates or the linear dinuclear Ag₂L₂ species.     

OXYPHOSPHORANE MODELS FOR NUCLEOPHILIC DISPLACEMENTS AT Pα AND Pγ OF ADENOSINE-5′ TRIPHOSPHATE

Abstract

The reaction of dimethylphosphorous triethylpyrophosphoric anhydride, (CH₃O)₂POP(O)(OC₂H₅)OP(O)(OC₂H₅)₂, with hexafluorobiacetyl, CF₃COCOCF₃, yields 4,5-bis(trifluoromethyl)2,2-dimethoxy-2-triethylpyrophosphato-2,2-dihydro-1,3,2-dioxaphospholene. This oxyphosphorane, with a pyrophosphate group at the apical position of trigonal bipyramidal phosphorus, simulates the pentacovalent intermediate in the addition-elimination mechanism of nucleophilic displacements at the Px and Py centers of adenosine-5′ tri-phosphate. The oxyphosphorane is remarkably stable in solution, although the pyrophosphate group is easily displaced by an alkoxy group in base-catalyzed reactions with alcohols.     

Layered Intergrowth Phases Bi4MO8X (X=Cl, M=Ta and X=Br, M=Ta or Nb): Structural and Electrophysical Characterization

The high-temperature structural behavior of the layered intergrowth phase Bi₄TaO₈Cl, belonging to the Sillén-Aurivillius family, has been studied by powder neutron diffraction. This material is ferroelectric, space group P2₁cn, at T_C<640 K. An order-disorder transition to centrosymmetric space group Pmcn is found around 640 K, which involves disordering of TaO₆ octahedral tilts. A second phase transition, of a first-order nature, to space group P4/mmm occurs at a temperature of ∼1038 K. The crystal structures of the bromide analogs Bi₄MO₈Br (M=Nb, Ta) have also been determined at room temperature; both are isomorphous with Bi₄TaO₈Cl and exhibit maxima in dielectric constant at temperatures of approximately 588 and 450 K, respectively.     

Functionalization of 8-aza-D-homogona-1,3,5(10),13-tetraene-12,17a-diones at positions 11 and 17 under the conditions of the claisen ester condensation. Synthesis and properties of 11- and 17-acylsubstituted 8-aza-d-homogonanes

It was shown that 8-aza-D-homogona-1, 3, 5(10),13-tetraene-12,17a-diones enter into the Claisen ester condensation at the C(₍₁₁₎H₂ and C₁₇H₂ groups, whereas the C₍₁₅₎H₂ group is inert under the investigated conditions. It was established that the direction of the reaction is determined by the structure of the 8-azasteroid substrate. In the presence of a bulky gem-dimethyl group at position 16 the reaction takes place exclusively at the C₁₁H₂ group, while in the absence of this restriction the C₍₁₁₎H₂ and C₍₁₇₎H₂ groups are equivalent. The data from IR, UV, and¹H and¹³C NMR spectroscopy of the initial and synthesized derivatives of 3-aza-D-homogonanes are presented and discussed.Institute of Bioorganic Chemistry, Academy of Sciences of Belarus', Minsk. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 7, pp. 959–965, July, 1995. Original article submitted May 6, 1995.     

Some conformational peculiarities of cardenolides and bufadienolides

Summary 1. The capacity of the cardenolides and bufadienolides of the A/B-trans series having an aldehyde group at C₁₀ for giving a semiacetal form is due to the conformational features of ring A, which may be present in a chairboat equilibrium.2. The aldehyde group of strophanthidin does not participate in the formation of an intramolecular hydrogen bond with the hydroxyl group at C₃ and C₅; an intramolecular hydrogen bond occurs between the hydroxyl groups at C₃ and C₅.Khimiya Prirodnykh Soedinenii, Vol. 2, No. 3, pp. 179–184, 1966     

ChemInform Abstract: Structure of the Ammonia-Boryl Radical (BH2NH3), an Inorganic Analogue of the Ethyl Radical. A Non Empirical Study

at the UHF-SCF level employing the 6-31*G basis set including complete geometry optimization on various possible conformations suggests that the distortion of the BH₂ group is higher than the corresponding distortion of the CH₂ group in the isoelectronic CH₂CH₃ and CH₂NH₃ radicals.     

Phosphaniminato-Komplexe von Niob und Tantal. Die Kristallstrukturen von [NbCl4(NPiPr3)(CH3CN)], [NbCl3(NPiPr3)2], [TaCl4(NPiPr3)]2 und [TaCl3(NPiPr3)2]

Phosphorane Iminato Complexes of Niobium and Tantalum. Crystal Structures of [NbCl₄(NPⁱPr₃)(CH₃CN)], [NbCl₃(NPⁱPr₃)₂], [TaCl₄(NPⁱPr₃)]₂, and [TaCl₃(NPⁱPr₃)₂] The title compounds have been prepared from the pentachlorides of niobium and tantalum with the silylated phosphorane imine Me₃SiNPⁱPr₃. They are characterized by IR spectroscopy and crystal structure determinations. NbCl₄(NPⁱPr₃)(CH₃CN)] . Space group Pna2₁, Z = 4, 2102 observed unique reflections, R = 0.022. Lattice dimensions at ?50°C: a = 1627.2, b = 876.3, c = 1335.3 pm. The compound forms monomeric molecules with the acetonitrile molecule in trans position to the phosphorane iminato group. This group shows a short NbN distance of 178.2 pm with a NbNP bond angle of 165.2°. [NbCl₃(NPⁱPr₃)₂] . Space group Cc, Z = 4, 2534 observed unique reflections, R = 0.046. Lattice dimensions at 20°C: a = 1302.65, b = 1321.69, c = 1672.04 pm, β = 111.713°. The compound forms monomeric molecules with a distorted bipyramidal surrounding of the niobium atom and equatorially arranged phosphorane iminato groups. [TaCl₄(NPⁱPr₃)]₂ . Space group Pbca, Z = 4, 1537 observed unique reflections, R = 0.037. Lattice dimensions at ?40°C: a = 1420.6, b = 1483.9, c = 1622.0 pm. The compound forms centrosymmetric dimeric molecules with dissimilarly long Ta₂Cl₂ bridges and equatorially arranged phosphorane iminato groups. [TaCl₃(NPⁱPr₃)₂] . Space group Cc, Z = 4, 5737 observed unique reflections, R = 0.039. Lattice dimensions at ?50°C: a = 1303.9, b = 1327.2, c = 1682.1 pm, β = 111,92°. The compound is isotypical with the corresponding niobium compound.     

Grafting onto carbon black by the reaction of reactive carbon black having masked isocyanate or acyl azide group with functional polymers

Although isocyanate group (NCO) introduced onto carbon black surface was inactivated rapidly upon storage, it could be stabilized by masking the NCO group with active hydrogen compounds such as acetylacetone, diethyl malonate, and sodium hydrogensulfite. Upon heating these carbon blacks having masked NCO group at 150°C, the NCO group was regenerated on carbon black by the decomposition of the masked NCO group. On the other hand, acyl azide (CON₃) group introduced onto carbon black was stable at below 20°C, but readily decomposed to NCO group by heating. By means of the reaction of NCO group on carbon black with functional polymers having hydroxyl, amino, and carboxyl group, these polymers were effectively grafted onto carbon black surface. When carbon black having CON₃ group was used as reactive carbon black, the grafting ratio of diol-type polyethylene glycol (M_n = 8.2 × 10³), polyethyleneimine (M_n = 2.0 × 10⁴), polyvinyl alcohol (M_n = 2.2 × 10⁴), and bifunctional carboxyl-terminated polystyrene (M_n = 1.1 × 10⁵) was determined to be 29.7, 81.7, 32.2, and 50.4%, respectively. The number of grafted polymer chain decreases with an increase in molecular weight of the polymers, because the shielding effect of NCO group by grafted polymer chain is enhanced with an increase in molecular weight of the polymer.     

Kinetics of substitution at ternary titanium(IV)–cyclopentadienyl,pyronato or pyridinato–halide or alkoxide complexes

Rate laws and kinetic parameters are reported for substitution at titanium(IV) complexes Ti(LL)₂X₂, where LLH=cyclopentadiene, the 4-pyrone ethylmaltol, several 4-pyridinones, and related ligands, and X=halide or alkoxide, in acetonitrile solution at 298.2 K. Reactivities are discussed in terms of the nature of the leaving group, the entering group and the non-leaving ligand LL^?. Activation volumes of ?15 and ?12 cm³ mol^?1 have been determined for thiocyanate attack at Ti(cp)₂Cl₂ and Ti(etmalt)₂Cl₂ respectively. Substitution mechanisms are discussed in the light of the kinetic parameters obtained.     

The Partial Molar Volume and Heat Capacity of the Glycyl Group in Aqueous Solution at 25^C

The partial molar volumes, V₂ ^{^}, and the partial molar heat capacities, C_p,2 ^{^}, at infinite dilution have been determined for three new peptides of sequence seryl(glycyl)_xglycine, where x=0 to 2, in aqueous solution at 25^{^}C. Values for V₂ ^{^} at 25^°C have also been determined for two neutral peptide derivatives N-acetylglycylglycinamide and N-acetylglycylglycylglycinamide. These V₂ ^°; and C_p,2 ^°; results were used to estimate the partial molar volume and heat capacity of the backbone glycyl group, CH₂CONH, of proteins in aqueous solution at 25^°;C. The results obtained are compared with those calculated using partial molar data for alternative model compounds. The new glycyl group contributions are in excellent agreement with those currently used in our group additivity schemes for the calculation of the partial molar volumes and heat capacities of unfolded proteins.     

Site of gas-phase methylation of l-phenyl-2-aminopropane

The regioselectivity of methyl cation transfer from (CH₃)₂F⁺, (CH₃)₂Cl⁺ and (CH₃)₃O⁺ to 1-phenyl-2-aminopropane was studied by Fourier transform ion cyclotron resonance in combination with collision-induced dissociation and neutralization-reionization mass spectrometry of the stable [M + CH₃]⁺ ions formed in a chemical ionization source. The (CH₃)₂F⁺ ion transfers a methyl cation to the NH₂ group and the phenyl ring with almost equal probability. Predominant CH₃⁺ transfer to the NH₂ group is observed for the (CH₃)₂Cl⁺ ion whereas the (CH₃)₃O⁺ ion reacts almost exclusively at the amino group. The preference for methylation at NH₂ is discussed in terms of a lower methyl cation affinity of the phenyl ring than of the amino group and the existence of an energy barrier for methylation of the phenyl moiety.