Hydrate formation in a tetrapropylammonium hydroxide-water system

The phase diagram of a tetrapropylammonium hydrate-water binary system was studied by differential thermal analysis. Five tetrapropylammonium hydroxide hydrates were found; two of these are stable and have compositions of 1: 4 (salt: water, mp 0.0°C) and 1: 11 (mp −17°C) and three are metastable and have compositions of 1: 5 (mp −3.5°C), 1: 6 (mp −71.0°C), and 1: 16 (mp −44.5°C).     

Formation of (C x H2x+1)4NBr·nH2O (x = 1–3) hydrate

The phase diagram of the binary system tetramethylammonium bromide-water was studied by the differential thermal analysis. In the stable region two phases, ice and the salt itself, were detected, and in the metastable region, three tetramethylammonium bromide hydrates (bromide-water, 1 : 4, mp 68.8°C, 1 : 5, mp 36.0°C, 1 : 7.5, mp ?19.5°C) were found. Formation of (C _x H_2x+1)₄NBr·nH₂O (x = 1–3, n = 4, 5, 7.5) hydrates was revealed.     

8,13-Epoxylabd-14-en-19-oic acid — A component of the needles ofPinus sylvestris

8,13-Epoxylabd-14-en-19-oic [(mannoyl oxide)-19-oic] acid, mp 64–66°C, [α]_D ?39.2° (c 1.0; ethanol) has been isolated from the needles ofPinus sylvestris. The following derivatives have been obtained: methyl 8,13-epoxylabd-14-en-19-oate, with mp 83–85°C, [α]_D ?43.2° (c 1.2; ethanol); 8,13-epoxylabd-14-en-19-ol, an oil, [α]_D ?10.9° (c 1.0; ethanol), n _D ²⁵ 1.5025, cyclohexylammonium salt with mp 113–115°C, [α]_D ?29.3° (c 1.0; ethanol); and 8,13-epoxydihydrolabd-14-en-19-oic acid with mp 61–63°C, [α]_D ?23.1° (c 1.0; ethanol). The structures of the compounds were established by IR, mass, PMR, and¹³C NMR spectroscopy.     

Volumetric, viscometric and refractive index behavior of some α-amino acids in aqueous tetrapropylammonium bromide at different temperatures

Densities, ρ, viscosities, η, and refractive indices, n _D, of glycine (Gly), DL-alanine (Ala), DL-valine (Val) (0.05, 0.10, 0.15, 0.20, 0.25 mol kg^?1), and L-leucine (Leu) (0.02, 0.05, 0.10 mol kg^?1) in water and in 0.20 mol kg^?1 aqueous tetrapropylammonium bromide (TPAB) have been measured at 298.15, 303.15, 308.15, and 313.15 K. The density data have been utilized to calculate apparent molar volumes, ?_v, partial molar volumes at infinite dilution, ?_v°, and partial molar volumes of transfer, ? _v°(tr) of amino acids. The viscosity data have been analyzed by means of Jones-Dole equation to obtain Falkenhagen coefficient, A, and Jones-Dole coefficient, B, free energy of activation of viscous flow per mole of solvent, Δµ₁°*, and solute, Δµ₂°*, and enthalpy, ΔH*, and entropy of activation, ΔS*, of viscous flow. The refractive index data have been used to calculate molar refractivity, R _D, of amino acids in aqueous tetrapropylammonium bromide solutions. It has been observed that ?_v°, B-coefficient and Δµ₂°* vary linearly with increasing number of carbon atoms in the alkyl chain of amino acids, and they were split to get contributions from the zwitterionic end groups (NH₃ ⁺, COO^-) and methylene group (CH₂) of the amino acids. The behavior of these parameters has been used to investigate the solute-solute and solute-solvent interactions as well as the effect of tetrapropylammonium cation (C₃H₇)₄N⁺ on these interactions.     

Flavonoids of inflorescences of Calendula officinalis

By column chromatography on polyamide sorbent, the inflorescences of pot marigold calendula have yielded eight substances of flavonoid nature: two aglycons — quercetin (C₁₅H₁₀O₇, mp 309–311°C) and isorhamnetin (C₁₆H₁₂O₇, mp 314–316°C); six glycosides, of which three have been identified as isoquercetin (C₂₁H₂₀O₁₂, [α] _D ²⁰ ?36° in methanol, mp 218–220°C), isorhamnetin 3-O-β-D-glucoside (C₂₂H₂₂O₁₂, [α] _D ²⁰ ?59° in dimethylformamide, mp 193–195°C), narcissin (C₂₈H₃₂O₁₆, [α] _D ²¹ ?28° in dimethylformamide, mp 180–182°C), and three substances that have proved to be new and have been called calendoflaside (C₂₈H₃₂O₁₅, [α] _D ²¹ ?85° in methanol, mp 192–195°C; calendoflavoside (C₂₈H₃₂O₁₆, [α] _D ²⁰ ?106° in methanol, mp 189–192°C), and calendoflavobioside (c₂₇H₃₀O₁₆, [α] _D ²⁰ ?105° in methanol, mp 194–197°C).     

Study on the equilibrium in the MCl2?CH3OH?H2O System (M = Sr2+, Ba2+) at 25°C and 50°C

Studies on the equilibrium in the system MCl₂? CH₃OH? H₂O at 25°C and 50°C (M = Sr²⁺, Ba²⁺) show that the dehydration in the water-methanol systems proceeds stepwise and all possible lower crystal hydrates may be obtained at 25°C depending on the molar ratio for the mixed solvent. The dehydration and solvation processes in the three-component system MCl₂? CH₃OH? H₂O (M = Mg²⁺, Ca²⁺, Sr²⁺, Ba²⁺) have been considered in general and compared with those in the bromide system.     

Coumarins ofHapolophyllum obtusifolium. Structures of two new coumarin glycosides

Two coumarin glycosides have been isolated from an aqueous ethanolic extract of the epigeal part ofHaplophyllum obtusifolium: (I) — C₁₆H₁₆O₁₀, mp 164–166°C, [α]_D ?52.4° (dimethylformamide); and (II) — C₂₆H₂₆O₁₂, mp 206–208°C, [α]_D ?110.5° (pyridine). It has been established on the basis of chemical transformations and spectral characteristics that (I) has the structure of fraxetin 7-O-β-D-glucopyranoside and (II) that of scopoletin 7-O-(6′-O-feruloyl-β-D-glucopyranoside).     

Structural Study on Water-induced Phase Transitions of Poly(ethylene imine) as Viewed from the Simultaneous Measurements of Wide-Angle X-ray Diffractions and DSC Thermograms

Thermal behavior of poly(ethylene imine) [PEI] has been studied using simultaneous WAXD/DSC measurement system. PEI exhibits water-induced and thermally-induced phase transitions among four kinds of crystalline hydrates: anhydrate (EI/water = 1/0), hemihydrate (1/0.5), sesquihydrate (1/1.5), and dihydrate (1/2). The chain conformation changes from a double helix in the anhydrate to a planar zigzag form in the three hydrates. The anhydrate melts at 60 °C while the hydrates melt differently in the temperature region of 70–110 °C. By means of the simultaneous WAXD/DSC measurements, complex DSC thermograms of PEI hydrates were characterized on the basis of X-ray diffractions obtained concurrently.     

Structure and configuration of a new diterpenoid lactone fromLagochilus hirsutissimus

The epigeal part of the plantLagochilus hirsutissimus has yielded a new diterpenoid lactone — lagohirsidin, C₂₂H₃₄O₅, mp 144–145°C, [α] _D ²² ? 17.5° (c 1; ethanol). Reduction with LiAlH₄ has yielded a diol C₂₂H₃₈O₅, mp 165–166°C [α] _D ²⁰ ?1.2 (c 0.6; ethanol). Acid hydrolysis of the diol has led to the formation of lagochilin, C₂₀H₃₆O₅, mp 167–168°C, [α] _D ²⁰ ?3.9° (c 1; ethanol). The synthesis of lagohirsidin from lagochilin has been effected.     

Clathrate formation in the series of systems diisopentyldibutylammonium halide-water

Three clathrate hydrates: (i-C₅H₁₁)₂·(C₄H₉)₂NCl·38H₂O (mp 20.5°C), (i-C₅H₁₁)₂·(C₄H₉)₂NCl·32H₂O (mp 22.2°C), and (i-C₅H₁₁)₂·(C₄H₉)₂NCl·27H₂O (mp 23.8°C) were detected in the system diisopentyldibutylammonium chloride-water. Crystals of all the compounds were isolated, and their composition was determined. The size effect of the halide anions (F^?, Cl^?, and Br^?) on the properties of related compounds was considered.     

Hydrate formation in the system n-propanol–water

The phase diagram of the binary system n-propanol alcohol–water was investigated with use of differential thermal analysis and powder X-ray diffraction. The phase diagram has three groups of thermal effects, which can be considered as peritectic melting of three different hydrates (?60.0, ?53.5, and ?41.5 °C). At the same time, powder X-ray diffraction data indicate the existence of only one compound in this system (cubic unit cell, a = 12.09 ± 0.01 Å and 12.15 ± 0.01 Å at ?109 to ?66 °C, respectively). The most probable explanation of this contradiction seems to be the existence of several hydrates belonging to the same structural type but different in composition.     

Hydrate schwacher und starker Basen. XI. Die Kristallstrukturen von NaOH · 3,5H2O und NaOH · 7 H2O. Eine Präzisierung

Hydrates of Weak and Strong Bases. XI. The Crystal Structures of NaOH · 3,5H₂O and NaOH · 7 H₂O. A Refinement The crystal structures of the hydrates NaOH · 3,5 H₂O (space group P2₁/c, Z = 8 formula units per unit cell; lattice parameters: a = 6.481, b = 12.460, c = 11.681 Å, β = 104.12° at ?100°C) and NaOH · 7 H₂O (P2₁/c, Z = 4; a = 7.344, b = 16.356, c = 6.897 Å, β = 92.91° at ?150°C) have been redetermined using MoKα diffractometer data. The obtained refinement of the structures, including the localization also of the H atoms for the first time, has led to new findings with respect to the H bonds. In particular, in both hydrates there is one such interaction of the rare type OH^? …? OH₂, from an OH^? ion to an H₂O molecule, i. e. with the OH^? ion as the proton donor.     

Clathrate hydrates of triisoamylbutylammonium iodide

The phase diagram of the (i-C₅H₁₁)₃C₄H₉NI?H₂O system is reported. Triisoamylbutylammonium iodide forms polyhydrates with hydration numbers of 36 (mp 12.5°C) and 32 (mp 13.2°C) and a dihydrate. Crystals of both polyhdrates have been isolated, and their compositions have been determined.     

Solvent-free polycondensation of 1,3-bis(hydroxyphenylmethyl)benzene. II. The dramatic difference in the polymerization behavior between meso and racemic isomers

The meso and racemic forms of 1,3-bis(hydroxyphenylmethyl)benzene underwent solvent-free polycondensation with the aid of an acid catalyst giving polyether. Very interestingly, the diastereoisomerism caused a considerable difference in the polymerization behavior. The meso isomer (mp = 96–98 °C) was polymerized even at 65 °C, whereas the racemic one (mp = 158–160 °C) required heating at 100 °C to undergo polymerization. However, the latter produced a much higher molecular weight than the former (30,000 vs 4000). The contamination of the meso isomer with the racemic one very sensitively reduced the polymerization temperature: the 98.5% meso monomer underwent polymerization at 50 °C. In contrast to solvent-free polymerization, two diastereomeric monomers showed almost identical behavior in solution polymerization. © 2003 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 41: 3564–3571, 2003     

Alkaloids ofRhinopetalum stenantherum. II. The structure of stenanthine and stenanthidine

From a methanolic extract of the epigeal part ofRhinopetalum stenantherum have been isolated β-chaconine (I) and the new glucoalkaloids stenanthine with mp 262–264°C [α]_D 46.5°, C₄₅H₇₃NO₁₅ (II), and stenanthidine with mp 269–271°C, [α]_D ?47.5°, C₃₉H₆₃NO₁₁ (III). On the basis of the facts that partial hydrolysis of the trioside (II) formed the biosides (I) and (III), and that on the hydrolysis of the latter the monoside γ-chaconine was found, it may be assumed that stenanthine has the structure of solanidine 3-0-{[0-β-D-glucosyl-(1 → 6)]-[0-α-L-rhamnosyl-(1 → 4)]-D-glucoside}, and stenanthidine that of solanidine 3-0-[0-β-D-glucosyl-(1 → 6)-D-glucoside].     

Triterpene glycosides of Thalictrum squarrosum. III. Structures of squarrogenins 1 and 2

Two genins — squarrogenin 1 and squarrogenin 2 — have been isolated from nodding meadow rue by the hydrolysis of squarrosides A1 and A2. The compounds are epimeric at C-21 and have the following structures: 1 — (21R, 22S, 23R)-21-methoxy-21,23-epoxycycloart-24-ene-3β,22β-30-triol, C₃₁H₅₀O₅, mp 169–171°C (hexane-acetone), [α] ₅₄₆ ²⁰ ?11.06° (c 4.52; pyridine); and 2 — (21S, 22S, 23R)-21-methoxy-21,23-epoxycycloart-24-ene-3β,22β,30-triol, C₃₁H₅₀O₅, mp 190–193°C (hexane-acetone), [α] ₅₄₆ ²⁰ +106.6° (c 0.3; pyridine). The results of¹H and¹³C NMR spectroscopy and of mass spectrometry for the new compounds are given.     

Transformed steroids. 118. The geometric isomerism of 20-ethoxycarbonylhydrazones of 3β-hydroxy-16,17α-cyclopropanopregn-5-en-20-one

In the reaction of the 3β-acetate of 3β-hydroxy-3′H-cyclopropano[16,17α]pregn-5-en-20-one (I) with ethoxycarbonylhydrazine in AcOH at 20°C (exposure for up to 6 days), a chromatographically separable equilibrium mixture of the 20Z-ethoxycarbonylhydrazone of 3β-acetoxy-3′H-cyclopropano[16,17α]pregn-5-en-20-one (II), with mp 190–195°C, and the 20E-ethoxycarbonylhydrazone of 3β-acetoxy-3′H-cyclopropano[16,17α]pregn-5-en-20-one (III) with mp 186–193°C (ratio 2:1) is obtained. The geometric isomers obtained are distinguished by IR, PMR, and CD spectroscopy. It has been shown that the observed geometric isomerism takes place via an intermediate enehydrazine form.     

Coordination compounds of copper(II) with substituted 3-{[(2-hydroxyphenyl)methylidene]amino}propane-1,2-diols

3-{[(2-Hydroxyphenyl)methylidene]amino}propane-1,2-diol, its 5-chloro-,5-bromo-, 5-nitro-, 3-methoxy derivatives, and 3-{[(2-hydroxynaphthyl-1)methylidene]amino}propane-1,2-diol react with hydrates of copper(II) chloride, bromide and nitrate in ethanol to form coordination compounds Cu(L)X·nH₂O. Template condensation reaction between 3-aminopropane-1,2-diol and 2,3-, 2,4- or 2,5-dihydroxybenzaldehyde in the presence of copper(II) nitrate trihydrate results in similar compounds Cu(L)NO₃·nH₂O. Structure of some of the condensation products was identified by X-ray analysis. Thermolysis of the substances obtained occurs through the dehydration step (70–90°C) and complete thermal decomposition (290–560°C).     

Steroids of the spirostand and furostan series from plants of the genusAllium. II. The structure of alliospiroside B fromAllium cepa

A new steroid glycoside — alliospiroside B (I) — has been isolated from the collective fruit ofAllium cepa L. On the basis of chemical transformations and with the aid of physicochemical measurements it has been established that compound (I) has the structure of (25S)spirost-5-ene-1β,3β-diol 1-O-[O-α-L-rhamnopyranosyl-(1 → 2)-β-D-galactopyranoside. Compound (I) C₃₉H₆₂O₃, mp 200–202°C (from ethanol). [α] _D ²⁰ ?110.9±2° (c 1.01; pyridine) was obtained by extracting the collective fruit ofA. cepa with ethanol folowed by the column chromatographic separation of the combined glycosides on silica gel. The acid hydrolysis of (I) gave (25S)-ruscogenin (II), C₂₇H₄₂O₄, mp 189–191°C, [α] _D ²³ ?104.1±2° (c 0.98; pyridine). The¹H and¹³C NMR spectra are given for both compounds and the IR spectrum for compound (I).     

Enthalpy and heat capacity parameters of ammonium bromide interaction with hexamethylphosphotriamide in water

Thermal effects of solution of ammonium bromide in hexamethylphosphotriamide (HMPT)-water mixtures at 4° C, 15°C, and 46°C in the region of minor additions of the nonaqueous component were investigated for the first time by calorimetry. Variations of heat capacity in the course of solution were calculated using previous data for 25°C and 40°C. The curves of the heat capacity of solution (transfer) and temperature variation of transfer entropy versus composition have a minimum near the region of the existence of the 1:20 HMPT:water clathrate. The enthalpy, heat capacity, and temperature variations of the entropy coefficients of electrolyte amide pair and three-particle interactions in water were calculated in terms of MacMillan-Mayer theory. Within the framework of the group additivity method it is shown that the heat capacity coefficient of the bromide ion-HMPT pair interaction is negative and dictates temperature variations of enthalpy for ammonium bromide and tetraalkylammonium interactions with HMPT in water.