Tin(IV) complexes ofSchiff bases derived from salicylaldehyde and aminoalcohols

11 and 12 molar reactions of tin(IV) chloride with theSchiff bases, HO–C₆H₄CHNROH [where R=–(CH₂)₂–, –CH₂–, –CH(CH₃)–, –(CH₂)₃–, and –CH(C₂H₅)CH₂–] have been studied in different stoichiometric ratios and derivatives of the type SnCl₄(SBH₂) and SnCl₄(SBH₂)₂ (whereSBH₂ represents theSchiff base molecule) have been isolated. These have been characterised by elemental analysis, conductivity measurements and I.R. spectral studies.     

Two-color photoionization spectroscopy of jet-cooled nickelocene

Two-photon ionization of the nickelocene molecules cooled in a supersonic jet was performed for the first time by simultaneous excitation of (⁵–C₅H₅)2Ni with two tunable nano- second dye lasers. The one-photon transition from the HOMO to the Rydberg R4p level was used as the initial step of the multiphoton excitation. In a one-color experiment, the conditions were found for generation of the intact molecular ion, (⁵–C₅H₅)2Ni⁺, as the only ionic product of the multiphoton ionization. The use of an intense pulse of the second dye laser lead to an increase in the yield of the molecular ion.Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 8, pp. 1604–1606, August, 2004.     

Monte Carlo Studies of the Structural and Thermodynamic Properties of Some Smectic and Ferroelectric Liquid Crystals

Monte Carlo simulation based on the Gaussian overlap model was used to study the thermodynamic properties of smectic C: C₅H₁₁O–(OH)C₆H₃–CH=N–C₆H₄–C₅H₁₁ (A), C₁₀H₂₁O–C₆H₄–CH=CH–C₆H₄–OC₁₀H₂₁ (B), ferroelectric smectic C* liquid crystals (LC): C₇H₁₅O–C₆H₄–C₆H₄–COO–CH₂C*H(CH₃)C₂H₅ (C), C₈H₁₇O–C₆H₄–C₆H₄–C₂H₄C*H(CH₃)C₂H₅ (D), and an equimolar mixture of {A+C} and {A+D}. A system of N = 125 pairwise interacting ellipsoids of revolution placed in a volume V at a temperature T (that is, a system described by a canonical NVT-ensemble) is considered. These interactions were calculated using a specially devised Lennard-Jones potential, allowing for both mild anisotropic repulsion of particles (ellipsoids) and their dispersion attraction. Dipole–dipole interactions were also taken into account, since the molecules have highly polar groups: –O–, OH, CH=N, and COO and hence a high dipole moment (4.2-5.3 D). Calculations were carried out for a rectangular parallelepiped with periodic boundary conditions imposed on its faces. An elementary object of the NVT-ensemble was a two-molecule microcluster (dimer) but not a single molecule from the group under study. Smectic A ordering in the system has been unambiguously proven for different temperatures and fixed densities (0.32 0.44, where is the close packing coefficient). The ordering is attributed to the large (transverse) dipole moment inherent in molecules {A}-{D}. Temperature dependences of free energy, configuration energy, heat capacity C_v, and orientational order parameter were obtained. The curves agree well with the experimental data on variation of the properties of smectic LC.     

Mechanism of the monomolecular thermal decomposition of 1,5- and 2,5-disubstituted tetrazoles

The kinetic parameters of the thermal decomposition of several pairs of 1(2)-R-5-R-disubstituted tetrazoles have been determined using the manometric method. The isomers differ only by the position of the substituents linked with the heterocyclic nitrogen atom. The activation entropies are equal to ca. +8 cal mol^–1 K^–1, the activation energies range from 39 to 48 kcal mol^–1. A linear correlation between the logarithms of the rate constants of decomposition of the isomers has been established. The limiting stages of the stepwise mechanism of the monomolecular decomposition, which determines the experimental rates of nitrogen evolution, include the reversible formation followed by decomposition of intermediate azidoazomethines in the case of 1,5-disubstituted tetrazoles and azodiazo compounds for isomeric 2,5-disubstituted tetrazoles. The enthalpies of formation of R(N₃)C=NR (R = Me, Ph), C₂H₃(N₃)C=NMe and increments _f H°[C_d–(C)(N₃)], _f H°[C_d-(C_b)(N₃)], and _f H°[C_d–(C_d)(N₃)] have been estimated.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 9, pp. 2209–2215, September, 1996.     

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, [] _D ²⁰ –36° in methanol, mp 218–220°C), isorhamnetin 3-O--D-glucoside (C₂₂H₂₂O₁₂, [] _D ²⁰ –59° in dimethylformamide, mp 193–195°C), narcissin (C₂₈H₃₂O₁₆, [] _D ²¹ –28° in dimethylformamide, mp 180–182°C), and three substances that have proved to be new and have been called calendoflaside (C₂₈H₃₂O₁₅, [] _D ²¹ –85° in methanol, mp 192–195°C; calendoflavoside (C₂₈H₃₂O₁₆, [] _D ²⁰ –106° in methanol, mp 189–192°C), and calendoflavobioside (c₂₇H₃₀O₁₆, [] _D ²⁰ –105° in methanol, mp 194–197°C).All-Union Scientific-Research Institute of Drug Chemistry, Khar'kov. Translated from Khimiya Prirodynkh Soedinenii, No. 6, pp. 795–801, November–December, 1988.     

Extraction characteristics of pertechnetate with tetraphenylarsonium in the presence of chloride,nitrate and perchlorate anions

Selected extraction systems of TcO ₄ ^– –(H,Na)A–H₂O/R(TcO₄,A)–CHCl₃, C₆H₅NO₂ type, where A=Cl^–, NO ₃ ^– , ClO ₄ ^– , R=(C₆H₅)₄As⁺, were studied. The solvent extraction of sub- and super-stoichiometric ratio of TcR was performed. The solubility of (C₆H₅)₄AsTcO₄ in water, chloroform and nitrobenzene were determined too. The results of the extractions are presented in the form of TcO ₄ ^– distribution dependencies on the phase composition and the extraction constants of individual TcO ₄ ^– , Cl^–, NO ₃ ^– , ClO ₄ ^– anions and TcO ₄ ^– -Cl^–, TcO ₄ ^– –NO ₃ ^– , TcO ₄ ^– –ClO ₄ ^– ion pairs.     

Magnetochemistry of boron hydride structures. Empirical aspects

The reviews and monographs on magnetochemistry of boron compounds are discussed. The structural peculiarities of borane derivatives relevant to magnetochemical calculations of diamagnetic contributions are are considered. Experimental measurements of diamagnetic susceptibility for deltahedral B₁₀H ₁₀ ^2– and B₁₂H ₁₂ ^2– cluster closo-anions were used to derive the diamagnetic atomic increments of the B atoms (_B) with coordination numbers 5 and 6. The atomic increments _B thus obtained were used to calculate molecular diamagnetic susceptibility _M of borane derivatives. Diamagnetic susceptibility _M was measured and calculated for the series of borane derivatives B_nH _n ^2– and B₁₀H₁₂L₂ (L is a Lewis base)and cobalt(III) derivatives of ortho-carborane(12) [(B₉C₂H₁₁)₂Co_n(B₈C₂H₁₀) _n–1] ^n–. Diamagnetic increments were obtained for |B₁₀H₁₂| fragments and (B₉C₂H₁₁)^2– and (B₈C₂H₁₀)^4– ligands. The increments can be employed for calculating _M for novel compounds. The calculated values of _M coincide with the experimental values within 2%–6%.Original Russian Text Copyright © 2004 by V. V. Volkov and V. N. IkorskiiTranslated from Zhurnal Strukturnoi Khimii, Vol. 45, No. 4, pp. 729–740, July–August 2004.This revised version was published online in April 2005 with a corrected cover date.     

Mass-spectrometric investigation of coordination compounds of nickel(II) with radical anions of S-alkyl-1-phenylisothiosemicarbazides

The electron-impact mass spectra of coordination compounds of nickel(II) with the general formula NiL₂, in which the radical anions [C₆H₅N -N-C(SR)=NR¹]^–, where R=CH₃ and R=H(I), R=CD₃ and R=H(II), R=C₂H₅ and R=H(III), and R=CH₃ and R=C₆H₅(IV), serve as the ligands, have been studied. In the mass spectra of compounds I–IV the peaks of the molecular ions have the highest intensity among the organometallic fragments. The initial stage of the fragmentation of [M]^+. is associated with the formation of the rearrangement ions [NiL + H]⁺, [NiL + C₆H₅]⁺, and [NiL + SR]⁺, ions, whose appearance becomes understood, if it is taken into account that the removal of one ligand is accompanied by the impairing of spins and the mass spectra of compounds I–IV is the presence of lines for the [NiL]⁺ ion in them. The dissociative ionization of compounds I–IV is strongly reminiscent of the behavior of ordinary complexes of metals with ligands of the nonradical type. The fragmentation scheme of the molecular ions under the effects of electron impact has been presented and discussed.Translated from Teoreticheskaya i Éksperimental'naya Khimiya, Vol. 26, No. 3, pp. 368–371, May–June, 1990.     

Molecular electrochemistry of hydrofullerenes C70H36—46

Electrochemistry of a mixture of hydrofullerenes C₇₀H_36—46 composed of C₇₀H₃₆, C₇₀H₃₈, C₇₀H₄₄, and C₇₀H₄₆ (50, 20, 14, and 15%, respectively) was studied by cyclic voltammetry in THF and CH₂Cl₂ in the –43—–13 °C temperature range. Two cathodic peaks, namely, one-electron reversible (E° = –3.16 V (Fc^0/+), Fc is ferrocene) and irreversible (E _p = –3.37 V (Fc^0/+)) were observed for this mixture in THF. The irreversible broad oxidation peak (E _p = 1.22 V (Fc^0/+)) was observed in CH₂Cl₂. The reversible reduction peak (E° = –3.16 V) and irreversible oxidation peak (E _p = 1.22 V) were attributed to the most stable hydrofullerene C₇₀H₃₆. The irreversible reduction (E _p = –3.37 V) and oxidation (E _p = 1.22 V) peaks were attributed to hydrofullerenes C₇₀H_44—46 with a higher degree of hydrogenation. The values of an electrochemical gap, which is an analog of the energy gap (HOMO—LUMO), are 4.38 and 4.59 V for C₇₀H₃₆ and C₇₀H_44—46, respectively, and indicate that these hydrofullerenes are sufficiently hard molecules with low reactivity in redox reactions.     

Magnetische Untersuchungen an Komplexen von La(III), Pr(III) und Nd(III) mitSchiffschen Basen

Specific magnetic susceptibilities (_s) of several newly synthesized chelates of some of the lanthanons [La(III), Pr(III) and Nd(III)] are reported. These derivatives are of the general type,Ln(O-i-C₃H₇)_3–n (C₆H₅CHNRO) _n [where,Ln=La(III), Pr(III) or Nd(III);n=1 or 2 and R=CH₂CH₂, CH₂CHCH₃ or C₆H₄] and have been prepared by the reaction of the alkoxides of the lanthanons withSchiff bases such as benzylidene-2-hydroxyethylamine (C₆H₅CHNCH₂CH₂OH), benzylidene-2-hydroxy-n-propylamine (C₆H₅CHNCH₂CHOHCH₃) and benzylidene-o-aminophenol (C₆H₅CHNC₆H₄OH) in different molar relations in dry benzene.The resulting crystalline derivatives are non-volatile, light to deep yellow or blackish in colour. These tend to polymerize on keeping as shown by their insoluble nature and higher melting points, the polymerisation possibly occurring by the intermolecular coordination through oxygen atoms as reported earlier¹.UsingGouy method², the bis-isopropoxy mono-Schiff base and mono-isopropoxy bis-Schiff base complexes of La(III) have been shown to be diamagnetic, with _s values being in the range of –0.32 to –0.45×10^–6 and –0.39 to –0.55×10^–6 c.g.s. units at 305 K respectively.In the remaining derivatives, Pr(O-i-C₃H₇)_3–n (C₆H₅CH NRO) _n and Nd(O-i-C₃H₇)_3–n (C₆H₅CHNRO) _n (where,n=1 or 2 and R=CH₂CH₂, CH₂CHCH₃ or C₆H₄) the magnetic moment values range between 3.25 to 3.32 and 3.30 to 3.33 _B respectively indicating their paramagnetic nature.     

Umsetzung von Alkalimetallphosphiden mit Salzen aromatischer Sulfonsäuren 2. Mitt.: Die Reaktion substituierter aromatischer Sulfonate mit Kaliumdiphenylphosphid

Zusammenfassung Die Umsetzung von Alkalidiphenylphosphid mit Methylaryl-sulfonaten zu tert. Phosphinen gelingt umso leichter, je weniger Methylgruppen der Arylrest enthält. Folgende Phosphine (C₆H₅)₂PR wurden dargestellt: R=2-CH₃C₆H₄–, 4-CH₃C₆H₄–, 2,4-(CH₃)₂C₆H₃– und 4-Methyl--naphthyl. Ebenso wurden die Phosphine mit R=3-(CH₃)₂NC₆H₄– und 2-(CH₃)₂NC₆H₄– aus den Dimethylanilinsulfonaten erhalten. Die Umsetzung von (C₆H₅)₂PK mit Na-1,4-Chlorbenzolsulfonat im Molverhältnis 2:1 gibt fast quantitativ 1,4-Phenylen-bis-diphenylphosphin, im Molverhältnis 1:1 aber entsteht (bei tieferen Temperaturen) Diphenylphosphin-p-benzolsulfonat. Diphenyl-(2,4,6-trimethyl-phenyl)phosphin wird am besten aus Diphenylchlorphosphin und Mesitylmagnesiumbromid hergestellt.Zusammenfassung Alkali diphenylphosphides react with methylarylsulfonates giving tert. phosphines. The yield increases with decreasing number of methyl groups in the arylsulfonate. The following phosphines (C₆H₅)₂PR were prepared: R=2-CH₃C₆H₄, 4-CH₃C₆H₄, 2,4-(CH₃)₂C₆H₃, and 4-methyl--naphthyl. Similarly the phosphines with R=3-(CH₃)₂NC₆H₄ and 2-(CH₃)₂NC₆H₄ were prepared from dimethylaniline sulfonates. The reaction of (C₆H₅)₂PK with sodium 1,4 chlorophenyl sulfonate at a molar ratio of 2:1 yields nearly quantitatively 1,4-phenylene-bis(diphenylphosphine); however at a mole ratio of 1:1 and at lower temperatures sodium diphenylphosphine-p-phenyl sulfonate is obtained. The best way to prepare diphenyl(2,4,6-trimethyl-phenyl)phosphine was to use diphenyl-chloro phosphine and mesitylmagnesium bromide.     

Phytoecdysones ofSilene praemixta. II. Premixisterone

The structure of premixisterone (I) — a new ecdysteroid fromS. praemixta M. Pop. (Caryophyllaceae) — has been established. Compound (I) has the composition C₂₇H₄₄O₅, mp 110–112°C (from C₂H₅OH + H₂O), [] _D ²⁴ 0 ± 4° (c 0.85; MeOH), 202 nm (log 3.35), _max ^KBr 3415 cm^–1 (OH), 1710 cm^–1 (C=0), and does not contain the ⁷-6-keto grouping that is characteristic of natural ecdysteroids. The acetylation of (I) with (CH₃CO)₂ in Py gave the amorphous 3,22-diacetylpremixisterone (II), C₂₁H₄₈O₇. Compound (I) has the structure of 3,14,22R,25-tetrahydroxy-5-cholest-8-en-6-one. The IR, PMR, and mass spectra of (I) and (II) are given.Institute of the Chemistry of Plant Substances, Academy of Sciences of the Uzbek SSR, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 6, pp. 797–799, November–December, 1979.     

The electronic effects of substituents containing phosphorus

Dissociation constants are reported for p-phosphorophenols, p-RC₆H₄OH, in aqueous alcohol (1:1 by volume), and the nucleophilic constants ^– of the R are found to be as follows: (C₆H₅)₂P 0.26, (C₆H₅)P(O) 0.68, (C₆H₅)₂P(S) 0. 63, and (C₆H₅)₂(CH₃)P⁺ 1.28.See [1–3] for previous communications in this series.     

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-3,22-30-triol, C₃₁H₅₀O₅, mp 169–171°C (hexane-acetone), [] ₅₄₆ ²⁰ –11.06° (c 4.52; pyridine); and 2 — (21S, 22S, 23R)-21-methoxy-21,23-epoxycycloart-24-ene-3,22,30-triol, C₃₁H₅₀O₅, mp 190–193°C (hexane-acetone), [] ₅₄₆ ²⁰ +106.6° (c 0.3; pyridine). The results of¹H and¹³C NMR spectroscopy and of mass spectrometry for the new compounds are given.Irkutsk Institute of Organic Chemistry, Siberian Division of the USSR Academy of Sciences. Translated from Khimiya Prirodnykh Soedinenii, No. 4, pp. 510–516, July–August, 1989.     

Formation,properties, and thermal decomposition of bisarene chromium(i) and molybdenum(i) fullerides

Fullerides [(⁶-Ph₂)₂Cr]⁺[C₆₀]^·–, [(⁶-C₁₀H₁₂)₂Cr]⁺[C₆₀]^·– (C₁₀H₁₂ is tetralin), and [(⁶-PhCH₃)₂Mo]⁺[C₆₀]^·– were synthesized. The molecular structure of [(⁶-Ph₂)₂Cr]⁺[C₆₀]^·– was established. In this compound at 100 K, radical anions C₆₀ ^–· are linked by an ordinary bond to form dimers, whereas at 293 K they are disordered and do not form dimers. The [(⁶-tetralin)₂Cr]⁺[C₆₀]^·– fulleride is stable in vacuo (10^–2 Torr) below 429 K, and [(⁶-toluene)₂Mo]⁺[C₆₀]^·– is stable below 581 K.Based on the materials presented at the International Conference Modern Trends in Organoelement and Polymer Chemistry (Moscow, May 30–June 4, 2004) dedicated to the 50th anniversary of the A. N. Nesmeyanov Institute of Organoelement Compounds of the Russian Academy of Sciences.Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 9, pp. 1973–1976, September, 2004.     

Synthesis and properties of polyamides and polyamidoesters based on bis-[N-alkyl-(or aryl-)aminomethyl]-phosphonic acids

Conclusions The activity of bis-[N-alkyl-(or aryl)-aminomethyl] phosphonic acids of the general formula (RNHCH₂)₂ in the interfacial polycondensation reaction with bisphenol A has been studied.In their activity the diamines studied can be placed in the following series: R=C₆H₅CH₂, C₄H₉, C₆H₅, C₃H₇.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 3, pp. 633–636, March, 1969.     

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, [] _D ²² – 17.5° (c 1; ethanol). Reduction with LiAlH₄ has yielded a diol C₂₂H₃₈O₅, mp 165–166°C [] _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, [] _D ²⁰ –3.9° (c 1; ethanol). The synthesis of lagohirsidin from lagochilin has been effected.V. I. Lenin Tashkent State University. Translated from Khimiya Prirodnykh Soedinenii, No. 6, pp. 788–792, November–December, 1979.     

Neutron Diffraction Analysis of H3Co2[C5H2(t-Bu)3]2, a Molecule with a Triply Hydrogen-Bridged Metal–Metal Bond: Some Comments on Structural Patterns in M(μ-H)nM Systems (n=1, 2, 3, 4)

The structure of H₃Co₂[C₅H₂(t-Bu)₃]₂ has been analyzed by low-temperature single-crystal neutron diffraction techniques, and shown to consist of two CoCp moieties with three hydride ligands bridging the central Co–Co bond. Despite a fairly extensive twinning problem, the structure could be solved and successfully refined to a final R factor of 9.2% for 2024 reflections. Average molecular parameters in the H₃Co₂ core of the molecule are as follows: Co–Co=2.275(21) Å, Co–H=1.637(16) Å, HH=2.050(20) Å, Co–H–Co=88.0(9)°, H–Co–H=77.0(7)°. Also included in this paper is a discussion on the molecular dimensions of symmetric hydride-bridged dinuclear systems (M(-H)_nM, n=1, 2, 3, 4) that have been studied to date by neutron diffraction.     

Group additivity for the standard partial molal heat capacities and volumes of polar compounds in methanol at 25°C

A flow heat capcity calorimeter and a flow vibrating tube densimeter have been used to measure the apparent molal heat capacities and volumes of benzene and 25 polar compounds in methanol at 25°C. These quantities have been extrapolated to infinite dilution to obtain the standard partial molal heat capacities and volumes. The and data have been used in conjunction with an additivity scheme previously determined for alkanes. Group contributions were evaluatd for –OH, –NH₂, –COOH, –C₆H₅, C=O, –COO–, –CONH–, –O–, –S–, and –S₂–. The concentration dependences of _cp and _v of nonelectrolytes in methanol are qualitatively similar but much smaller than in water.     

Die Schwingungsspektren von Trimethylsilyl-alkyl-bzw.-phenyl-aminen

Zusammenfassung Die Infrarot- und die Raman-Spektren der Silylamine (CH₃)₃Si–NH–R (R=CH₃, C₂H₅ und C₆H₅) sowie der analogen N-deuterierten Verbindungen werden mitgeteilt und analysiert. Starke Kopplungen führen zu einer Mischung vonv SiN bei etwa 700 cm^–1 mit anderen Schwingungen des C₃Si–NHR-Skelettes.

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The Infrared and Raman spectra of the silylamino compounds (CH₃)₃Si–NH–R (R=CH₃, C₂H₅, and C₆H₅) and the analogous N-deuterated species are reported and assigned. The SiN stretching mode at about 700 cm^–1 is strongly coupled with other vibrations of the molecules.