Zur Thermodynamik der Metallcarbonate. 4. Mitteilung. Potentiometrische Untersuchungen am System Mn2+?CO2?H2O

The solubility and the complex equilibria in the system Mn²⁺-CO₂-H₂O have been investigated at 25°C in solutions of the constant ionic strength 3 M (Na)ClO₄. From experimental data the following values for equilibrium constants and Gibbs free energies of formation are deduced: A predominance area diagram for the system Mn²⁺-H₂-CO_2(g)-H₂S_(g) including MnCO_3(ppt.), α-MnS and Mn²⁺ is given.     

Ammonia chemical ionization mass spectrometry of alcohols: Structural,stereochemical, molecular-size and temperature effects

Ammonia chemical ionization (CI) mass spectra of various open-chain, cyclic and unsaturated C₅- to C₁₀-alcohols were obtained at source temperatures ranging from 60° to 250°C. The reactivity of the ammonia adduct ion MNH and its fragmentation channels are characteristic for substrate structure. Although strongly temperature-dependent, the spectra give nevertheless information on the OH-group environment as well as on the C-skeleton at any source temperature. Primary, secondary and tertiary alcohols as well as allylic and simple olefinic alcohols can be distinguished by their spectra, which show ammonium adduct ions [MNH₄]⁺, adduct dehydrogenation ions [MNH₄-H₂], ammonium substitution ions [MNH₄-H₂O]⁺ and [M-OH]⁺-ions as the main characteristic peaks. Moreover, konfigurational assignments of stereoisomeric alcohols are possible for larger substrate-size and source-temperature ranges than with isobutane CI mass spectrometry. Homologous M NH-ions show molecular-size control of fragmentation and linear MNH-ions are less stable than branched isomers due to incomplete energy randomization.     

Comparative reactivity of substituted 1,3-and 1,4-thiasilinane <Emphasis Type="Italic">S</Emphasis>-oxides in the sila-Pummerer rearrangement and inversion of the thiocarbonyl group

The thermal sila-Pummerer rearrangement of diastereomeric 2,3,3-trimethyl-1,3-thiasilinane S-oxides was studied. Introduction of the methyl group in the 2 position of 3,3-trimethyl-3-thiasilinane S-oxide slows down the rearrangement. When heated in CCl₄, the trans isomer (2-Me_eq, SO_eq) converts into the cis isomer (2-Me_eq, SO_ax) which rapidly rearranges into 2,2,7-trimethyl-1,6,2-oxathiasilepane. On the contrary, the isomeric 2,4,4-trimethyl-1,4-thiasilinane S-oxide is thermally stable up to 160°C in DMSO. The inversion at the sulfur atom in 2,3,3-trimethyl-1,3-thiasilinane S-oxides and 2,4,4-trimethyl-1,4-thiasilinane S-oxides under the action of triethyloxonium tetrafluoroborate was studied. The trans isomer of 2,3,3-trimethyl-1,3-thiasilinane S-oxide (2-Me_eq, SO_eq) forms with Et₃O⁺BF ₄ ^? a salt which decomposes in two ways. The first involves recovery of the starting sulfoxide due to Sn2 substitution at the carbon atom of the ethoxy group, and the second, convertion into the cis isomer (2-Me_eq, SO_ax) which rearranges into 2,2,7-trimethyl-1,6,2-oxathiasilepane. Under the same conditions, the cis isomer of 2,3,3-trimethyl-1,3-thiasilinane S-oxide (2-Me_eq, SO_eq) decomposes to form siloxanes. trans-2,4,4-Trimethyl-4-thiasilinane S-oxide (2-Me_eq, SO_eq) under the action of Et₃O⁺BF ₄ ^? convers into the cis isomer (2-Me_eq, SO_ax). The B3LYP/6-311G(d,p) theoretical analysis showed that the thermal inversion at the sulfur atom in the compounds studied has a high energy barrier.     

Isotype 1D polymers of cobalt(II) or zinc(II) constructed with square-planar tetraaqua-metal(2+) units and the bis-zwitterionic form of the μ2-O,O′-trans-1,4-dihydrogen-cyclohexanediaminotetraacetate(2−) ligand

An uncompleted reaction between equimolar amounts of Co₂CO₃(OH)₂·2H₂O and trans-1,4-H₄cyclohexanediaminotetraacetic acid in water affords the ‘acid’ complex {[Co^II(trans-1,4-H₂CDTA)(H₂O)₄]·6H₂O}_n (1). Its IR spectrum does not show the expected ν(CO) band of carboxylic groups. Reactions in aqueous solution between Na(trans-1,4-H₃CDTA) and Zn(AcO)₂·2H₂O or Na₂(trans-1,4-H₂CDTA) and Zn(NO₃)₂·6H₂O yield {[Zn(trans-1,4-H₂CDTA)(H₂O)₄]·6H₂O}_n (2) and {[Zn₂(trans-1,4-CDTA)(H₂O)₂]·H₂O}_n (3) respectively. Crystal structures of compounds 1-3 and that of the trans-1,4-H₄CDTA·2H₂O acid are reported. For steric reasons, in the four reported structures the 1,4-CDTA ligand has the two iminodiacetate moieties as equatorial groups in the 1,4-cyclohexanedi-yl chair. Compounds 1 and 2 are isotype 1D polymers constructed by square planar M^II(H₂O)₄²⁺ knots (M^II = Co^II or Zn^II) linked to bis-zwitterionic trans-1,4-H₂CDTA²⁻ ligands that play a typical μ₂-O,O′-dicarboxylate bridging role. These 1D polymeric structures seem to be favoured by the H-bonded intra-stabilization of the bis-zwitterionic trans-1,4-H₂CDTA²⁻ ligand. In the neutral complex (3), the trans-1,4-CDTA acts as a bridging bis-chelating ligand as well as a syn-anti carboxylate building a polymer where the zinc(II) centres exhibit a rough bipyramidal trigonal coordination.     

Synthesis of stereoisomeric 1,3-dimethyl- and 1,2,5-trimethyl-4-acyl(benzoyl)-4-piperidinols

In order to synthesize stereoisometric 4-acyl(benzoyl)-1, 3-dimethyl and-1, 2, 5-trimethyl-4-piperidinols, the reaction of the geometrical isomers of 4-cyano-1, 3-dimethyl- and -1, 2, 5-trimethyl-4-piperidinols and the amines and imidic esters corresponding to them with some alkyl- and arylmagnesium halides, leading to the corresponding isomeric piperidinic -ketols, has been studied. The dependence of the reactivity of the geometrical isomers of the compounds studied on the spatial orientation of their functional groups has been shown.     

Trägerfixierte Organometallkomplexe. VI. Charakterisierung und Reaktivität Polysiloxan-gebundener (Ether-phosphan)ruthenium(II)-Komplexe

Supported Organometallic Complexes. VI. Characterization und Reactivity of Polysiloxane-Bound (Ether-phosphane)ruthenium(II) Complexes The ligands PhP(R)CH₂D [R = (CH₃O)₃Si(CH₂)₃; D = CH₂OCH₃ ( 1b ); D = tetrahydrofuryl ( 1c ); D = 1,4-dioxanyl ( 1d )] have been used to synthesize (ether-phosphane)ruthenium(II) complexes, which have been copolymerized with Si(OEt)₄ to yield polysiloxane-bound complexes. The monomers cis,cis,trans-Cl₂Ru(CO)₂(P ～ O)₂ ( 3b ) and HRuCl(CO)(P ～ O)₃ ( 5b ) were treated with NaBH₄ to form cis,cis,trans-H₂Ru(CO)₂(P ～ O)₂ ( 4b ) and H₂Ru(CO)(P ～ O)₃ ( 6b ), respectively (P ～ O = η¹-P coordinated; = η²- coordinated). Addition of Si(OEt)₄ and water leads to a base catalyzed hydrolysis of the silicon alkoxy-functions and a precipitation of the immobilized counterparts 4b ′, 6b ′. The polysiloxane matrix resulting by this new sol gel route has been described under quantitative aspects by ²⁹Si CP-MAS NMR spectroscopy. 4b ′ reacts with carbon monoxide to form Ru(CO)₃(P ～ O)₂ ( 7b ′). Chelated polysiloxane-bound complexes Cl₂Ru( )₂ ( 9c ′, d ′) and Cl₂Ru( )(P ～ O)₂ ( 10b ′, c ′) have been synthesized by the reaction of 1b–c with Cl₂Ru(PPh₃)₃ ( 8 ) followed by a copolymerization with Si(OEt)₄. The polysiloxane-bound complexes 9c ′, d ′ and 10b ′, c ′ react with one equivalent of CO to give Cl₂Ru(CO)( )(P ～ O) ( 12b ′– d ′). Excess CO leads to the all-trans-complexes Cl₂Ru(CO)₂(P ～ O)₂ ( 14b ′– d ′), which are thermally isomerized to cis,cis,trans- 3b ′– d ′. The chemical shift anisotropy of ³¹P in crystalline Cl₂Ru( )₂ ( 9a , R = Ph, D = CH₂OCH₃) has been compared with polysiloxane-bound 9d ′ indicating a non-rigid behavior of the complexes in the matrix.     

New telechelic polymers and sequential copolymers by polyfunctional initiator-transfer agents (inifers). LIII. Lithiation of 2,4,4-trimethyl-1-pentene and isopropylidene-capped polyisobutylenes by butyllithiums in the presence of complexing agents

Lithiated isopropylidene-telechelic polyisobutylenes (i.e., PIBs capped with end groups) are most interesting novel intermediates for further transformations, e.g., functionalization, polymerization. This report concerns model lithiation experiments of 2,4,4-trimethyl-1-pentene (TM1P) that guided us toward the subsequent quantitative lithiation of isopropylidene-telechelic PIBs. Thus, lithiation of TM1P with, n-, s-, and t-butyllithium, in the presence of various complexing agents (i.e., TMEDA, t-BuOK, 1,2-DPE, CH₃OCH₂CH₂OCH₃, THF, and 12-crown-4) followed by silylation with Me₃SiCl (for the purpose of quantitation) gave three products: 2(trimethylsilylmethyl)-4,4-dimethyl-1-pentene (TM1P-Si), 2(trimethylsilylmethyl)-4,4-dimethyl-2-pentene (TM2P-Si₂). The relative product composition strongly depends on the BuLi/complexing agent ratio and temperature. Among the different butyllithiums and complexing agents the best overall results were obtained with the s-BuLi/TMEDA combination. Complete lithiation of TM1P with minimum dilithiation was obtained using the molar ratio [s-BuLi]: [TMEDA]: [TM1P] = 2 : 2 : 1. The apparent activation energy of lithiation by s-BuLi/TMEDA was found to be 6.7 ± 0.8 kcal/mol. Guided by TM1P model experiments, quantitative monolithiation of isopropylidene-capped polyisobutylene (including ca. 4% chain and isomerization) was achieved using the molar ratio [s-BuLi] : [TMEDA] : [C? C] = 5 : 4 : 1.     

A theoretical study on the red- and blue-shift hydrogen bonds of cis-trans formic acid dimer in excited states

The excited states of cis-trans formic acid dimer and its monomers have been investigated by time-dependent density functional theory (TDDFT) method. The formation of intermolecular hydrogen bonds O₁-H₁...O₂=C₂ and C₂-H₂...O₄=C₁ induces bond length lengthening of the groups related to the hydrogen bond, while that of the C₂-H₂ group is shortened. It is demonstrated that the red-shift hydrogen bond O₁-H₁...O₂=C₂ and blue-shift hydrogen bond C₂-H₂...O₄=C₁ are both weakened when excited to the S₁ state. Moreover, it is found that the groups related to the formation of red-shift hydrogen bond O₁-H₁...O₂=C₂ are both strengthened in the S1 state, while the groups related to the blue-shift hydrogen bond C₂-H₂...O₄=C₁ are both weakened. This will provide information for the photochemistry and photophysical study of red- and blue-shift hydrogen bond.      

Breakdown of the Rule of “Linearity of Water Isoactivity Lines” in a System Containing Solid Solutions

Osmotic coefficients of water have been measured isopiestically for the entire region of homogeneous ternary solutions for the Rb₂SO₄- (NH₄)₂SO₄-H₂O system at 25°C. One might expect that water isoactivity lines should be straight since this system involves a continuous series of solid solutions. The related systems (K₂SO₄-Rb₂SO₄-H₂O and (K₂SO₄- (NH₄)₂ SO₄-H₂O) obey the linearity of water isoactivity lines rule. Contrary to expectations, the (Rb₂SO₄-(NH₄)₂-SO₄-H₂O appears to be the first water–salt system containing continuous solid solutions in which the mentioned rule is not obeyed.     

Intermediates of Asymmetric Oxidation Processes Catalyzed by Vanadium(V) Complexes

The [VO(acac)₂]/Schiff base [R-2-(N-3,5-di-tert-butylsalicylidene)amino-2-phenyl-1-ethanol, S-2-(N-3,5-di-tert-butylsalicylidene)amino-3,3-dimethyl-1-butanol, S-2-(N-3,5-di-tert-butylsalicylidene)amino-3-methyl-1-butanol, or R-2-(N-3,5-di-tert-butylsalicylidene)amino-3-phenyl-1-propanol]/H₂O₂ catalytic systems for the asymmetric oxidation of sulfides and the [VO(acac)₂]/(3bR,4aR)-2-(3,4,4-trimethyl-3b,4,4a,5-tetrahydrocyclopropa[3,4]cyclopenta[1,2-c]pyrazol-1-yl)ethanol/tert-butyl hydroperoxide/TBHP and VO(OAlkyl)₃/[2,2]paracyclophane-4-carboxylic acid N-(1,1-dimethylethyl)-N-hydroxamide/TBHP catalytic systems for the asymmetric epoxidation of allylic alcohols were studied using ¹³C, ⁵¹V, and ¹⁷O NMR spectroscopy. The key intermediates of these systems (peroxo and alkylperoxo complexes of vanadium(V)) were detected, their structures in solution were studied, and the reactivity was evaluated.     

Indole derivatives

The Fischer cyclization of arylhydrazones of 1,3-dimethyl-, 1, 3, 5-trimethyl-, and 1, 3, 6-trimethyl-4-piperidones is examined. An unusual duration of the reaction is found, resulting in rearrangement products (1, 2, 3, 4-tetrahydropyrimido[3,4-a]indoles). It is shown that hydrogenation of the latter gives 2-(-dimethylaminoalkyl)-3-methylindoles.For Part XXX, see [1].Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 9, pp. 1219–1224, September, 1970.     

Clathrate formation in binary aqueous systems with CH2Cl2, CHCl3 and CCl4 at high pressures

P,T,X phase diagrams of the CH₂Cl₂-H₂O, the CHCl₃-H₂O and the CCl₄-H₂) systems have been studied by DTA in the pressure range 10^–3 to 5.0 kbar. Under pressure the cubic structure II (CS-II) hydrates forming in all the systems are replaced by hydrates with the composition M·7.3 H₂O whose stoichiometry and positive dT/dP values of melting lead us to believe that they are CS-I hydrates.In the CH₂Cl₂ and CHCl₃ systems the nonvariant point coordinates of the hydrate transformationQ ₂ ^h (l₁h17h7l₂, where l₁ and l₂ are liquid phases abundant in water and hydrate former, respectively, h₁₇ and h₇ are hydrates with hydrate numbers 17 and 7, respectively) areP = 0.6 kbar, T = –1.5°C andP =2.65 kbar,T = –10.5°C, respectively. In the CCl₄ system the 4-phaseQ ₃ ^h point (l₁h₁₇h₇s, where s is crystalline CCl₄) has coordinatesP = 0.75 kbar and T = 0.4°C.The main obstacle of the present study, the very slow achievement of equilibrium, has been eliminated by adding small amounts (0.25% by mass) of surfactants followed by ultrasonic mixing. We have shown that this accelerates the achievement of equilibrium without changing its position.     

N-substituted 2, 5-dimethyl-4-ethynyl(vinyl)piperid-4-ols

They -isomers of 1-(3-chlorobuten-2-yl)- and 1-benzyl-2,5-dimethyl-4-ethynylpiperid-4-ols (I, II) and of 1-(3-chlorobuten-2-yl)-2,5-diemethyl-4-vinylpiperid-4-ol (III) and the quaternary salts of compounds I–III and of the -isomers of the 1,2,5-trimethyl-4-ethynyl-(vinyl)piperid-4-ols [1] have been synthesized.     

Reaction of dimedone with aldehydes and β-aminovinyl carbonyl compounds

The unsymmetrical condensation of dimedone, an aldehyde, and various -aminovinyl carbonyl compounds, and also bisacetonitrile, has given 3, 4-disubstituted derivatives of 2, 7, 7-trimethyl-5-oxo-1, 4, 5, 6, 7, 8-hexahydroquinoline (Va-f). Compounds Va, d, f have been oxidized with H₂CrO₄ to the corresponding 3, 4-disubstituted 2, 7, 7-trimethyl-5-oxo-5, 6, 7, 8-tetrahydroquinolines (VIa-c). The IR spectra of compounds Va-c, f and VIa and the UV spectra of compounds Va, c, f, and VIa, c have been recorded.     

New method of synthesizing 1,2,5-trisubstituted piperidine derivatives by reaction of 1,3-dienes with urotropin in the presence of palladium complexes

Conclusions It has been shown for the first time that 1-(2,7-octadienyl)-2,5-divinyl- and 1-(2,7-dimethyl-2,7-octadienyl)-2, 5-diisopropenylpiperidine can be prepared by reacting urotropin with butadiene or isoprene in the presence of a Pd(acac)₂-PR₃-A1(C₂H₅)₃-H₂SO₄ catalyst (1321.5).Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 6, pp. 1359–1363, June, 1977.     

Polymorphism of Inclusion Complexes and Unsolvated Hosts. IV. Dimorphism of the Acetone Host–Guest Complex of Dianilinegossypol. Structures of the α- and β-Phase Complexes

Crystal structures of the - and -phase inclusion complexes of dianilinegossypol with acetone obtained at 20° and 30 °C, respectively, have been determined by X-ray structure analysis. Crystal data of the -phase complex are: C₄₂H₄₀O₆N₂2C₃H₆O, orthorhombic, space group Pccn, a = 29.501(9), b = 10.866(2), c = 13.756(3) Å, V = 4409(1) ų, Z = 4, D _x = 1.18 g cm^-3. The structure has been refined to a final R value of 0.117 for 1401 observed reflections. The host–guest ratio for the -phase complex is the same (1 : 2) and the crystals are monoclinic, space group C2/c, a = 28.352(6), b = 11.836(2), c = 13.196(1) Å, = 93.05(1)°, V = 4422(2) Å3, Z = 4, D _x =1.18 g cm^-3. The structure has been refined to a final R value of 0.077 for 1414 observed reflections.In both phases molecules of dianilinegossypol form hydrogen-bondedribbons by O(4)–-HO(3) H-bonds. Phases are determined by the same structural motif. In the -phase complex the cages are in the form of prisms but in the -phase clathrate they undergo a modification by shrinking in two directions and widening in one. Molecules of acetone are hydrogen bonded to the host molecules via aO(1)–-HO(G) bond and are accommodated in cavities for both complexes, i.e. both phases are cryptate-type inclusion complexes.Supplementary data relevant to this publicationhave been deposited with the British Library,No. SUP 82227 (24 pages).     

Selective Oxidation of Betulin by Cr(VI) Reagents

Oxidation of betulin by pyridinium dichromate, pyridinium chlorochromate, and K₂Cr₂O₇ -H₂SO₄ in the presence of tetrabutylammonium bromide was studied. Products of regioselective C-3, C-28-, and exhaustive oxidation, 28-hydroxylup-20(29)-3-one, 3-hydroxy- and 3-oxolup-20(29)-en-28-al were obtained.     

Diversity of coordination modes in the polymers based on 3,3′,4,4′-biphenylcarboxylate ligand

Four new compounds [Ni₂(4,4′-bpy)(3,4-bptc)(H₂O)₄]_n (1), [Ni(4,4′-bpy)(3,4-H₂bptc)(H₂O)₃]_n (2), [Mn₂(2,2′-bpy)₄(3,4-H₂bptc)₂] (3) and {[Mn(1,10-phen)₂(3,4-H₂bptc)]·4H₂O}_n (4) (3,4-H₄bptc=3,3′,4,4′-biphenyltetracarboxylic acid, 4,4′-bpy=4,4′-bipyridine, 2,2′-bpy=2,2′-bipyridine, 1, 10-phen=1, 10-phenanthroline), have been prepared and structurally characterized. In all compounds, the derivative ligands of 3,4-H₄bptc (3,4-bptc⁴⁻ and 3,4-H₂bptc²⁻) exhibit different coordination modes and lead to the formation of various architectures. Compounds 1 and 2 display the three-dimensional (3D) framework: 1 shows a 3,4-connected topological network with (8³)(8⁵·10) topology symbol based on the coordination bonds while in 2, the hydrogen-bonding interactions are observed to connect the 1D linear chain generating a final 3D framework. 3 exhibits the 2D layer constructed from the hydrogen-bonding interactions between the dinuclear manganese units. Complex 4 shows the double layers motif through connecting the 1D zigzag chains with hydrogen-bonded rings. The thermal stability of 1-4 and magnetic property of 1 were also reported.     

Cyanoethylation of some n-substituted 2,5-dimethyl-4-piperidones

1,2,5-Trimetnyl- and 1-(-chlorocrotyl)-2,5-dimethyl-5-(-cyanoethyl)-4-piperidones were synthesized and separated into individual isomers. The corresponding isomeric 5-(-carboxyethyl)-4-piperidones were obtained by hydrolysis. The isomeric 1,2,5-trimethyl-3,5-bis(-cyanoethyl)- and 1,2,5-trimethyl-3,3,5-tris(-cyanoethyl)-4-piperidones were synthesized by subsequent cyanoethylation of the individual 1,2,5-trimethyl-5-(-cyanoethyl)-4-piperidone isomers.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 4, pp. 479–481, April, 1971.