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Summary Signal transducers and activators of transcription (STATs) are key molecular determinants of T cell fate and effector function. Several inflammatory diseases are characterized by an altered balance of T cell phenotypes and cytokine secretion. STATs, therefore, represent viable therapeutic targets in numerous pathologies. However, the underlying mechanisms by which the same STAT proteins regulate both the development of different T cell phenotypes and their plasticity during changes in extracellular conditions remain unclear. In this study, we investigated the STAT-mediated regulation of T cell phenotype formation and plasticity using mathematical modeling and experimental data for intracellular STAT signaling proteins. The close fit of our model predictions to the experimental data allows us to propose a potential mechanism for T cell switching. According to this mechanism, T cell phenotype switching is due to the relative redistribution of STAT dimer complexes caused by the extracellular cytokine-dependent STAT competition effects. The developed model predicts that the balance between the intracellular STAT species defines the amount of the produced cytokines and thereby T cell phenotypes. The model predictions are consistent with the experimentally observed IFN-γ to IL-10 switching that regulates human Th1/Tr1 responses. The proposed model is applicable to a number of STAT signaling circuits. This article is protected by copyright. All rights reserved.

The abundance of fat tissue surrounding normal and malignant epithelial mammary cells raises the questions whether such “adipose milieu” is important in the local proinflammatory/genotoxic shift, which apparently promotes tumor development and worsens prognosis, and what conditions stimulate this shift, or “adipogenotoxicosis.” We studied 95 mammary fat samples from 70 postmenopausal and 25 premenopausal breast cancer (BC) patients at a distance of 1.5–2.0 cm from tumors. The levels of leptin, adiponectin, TNFα and IL-6 release after 4-hr incubation of the samples were evaluated with ELISA, nitric oxide (NO) production by Griess reaction and lipid peroxidation by determination of thiobarbiturate-reactive products (TBRP). Infiltration of fat with macrophages (CD68-positive cells) and expression of cytochrome P450 1B1/estrogen 4-hydroxylase (CYP1B1) were detected by immunohistochemistry. Aromatase (CYP19) activity in mammary fat was measured by 3H2O release from 3H-1β-androstenedione. In the postmenopausal BC patients, NO and TNFα production by adipose tissue explants increased independent of BMI and in parallel with decreasing leptin and, especially, adiponectin release. In the premenopausal patients, higher CYP1B1 expression and TBRP level were found in mammary fat, while higher aromatase activity was combined with higher CYP1B1 expression as well as NO and IL-6 production. In the postmenopausal group, impaired glucose tolerance was associated with higher IL-6 release production by fat and with higher IL-6/adiponectin ratio. Thus, signs of adipogenotoxicosis in mammary fat can be found in both pre- and postmenopausal BC patients. This condition is likely being maintained through estrogen- and glucose-related factors and mechanisms presumably associated with less favorable types of hormonal carcinogenesis. © 2007 Wiley-Liss, Inc.

The N,O-chelate ligands 2-(iminoethyl)pyridine N-oxide (2a) and 2-(iminoethyl)-6-isopropylpyridine N-oxide (2b) were prepared by conventional synthetic routes, the latter involving a variant of the Reissert–Henze reaction. Treatment of 2a with FeCl2 resulted in a deoxygenation reaction of the ligand and formation of the salt [bis{2-(iminoethyl)pyridine}FeCl]+[FeCl4]– (18a). In contrast, the reaction of 2a with PdCl2 or CoCl2 cleanly furnished the six-membered chelate [κN,O-2(iminoethyl)pyridine N-oxide]MCl2 complexes (19a, M = Pd) or (20a, M = Co), respectively, which were both characterised by X-ray diffraction. Treatment of 2b with [NiBr2(dme)], followed by crystallisation from THF, gave the complex [(κN,O-2b)NiBr2(THF)] (21b), which features a distorted trigonal-bipyramidal coordination geometry of the central metal atom. The reaction of 2a with [NiBr2(dme)] gave the structurally related complex [(κN,O-2a)NiBr2(κO-2a)] (21a). The N,O-chelate Pd complex 19a was shown to be an active catalyst for the Suzuki coupling reaction. The ligand systems 2a,b and their related 2-(iminoethyl)pyridines 3a,b and a variety of metal complexes of ligands 3 were also prepared and characterised for comparison by X-ray diffraction. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)

A series of new zirconium dichloride complexes bearing bulky cis-bis(amino)cyclodiphosph(III)azane ligands, [(RN)2(tBuNP)2]ZrCl2 [R = phenyl (7), diphenylmethyl (8), 2,6-diethylphenyl (9), 2,5-di-tert-butylphenyl (10), and 2,6-diisopropylphenyl (11)] were prepared in high yields by a two-step synthetic route. The structure of cis-[(Ph2CHN)(tBuNP)]2Zr(NMe2)2 (8a), determined by X-ray analysis, shows that the zirconium atom has a distorted trigonal-bipyramidal configuration consisting of four equidistant metal−amido nitrogen bonds and an additional coordination between the metal and a nitrogen atom from the cyclodiphosph(III)azane ring. After methylaluminoxane activation, these complexes exhibit moderate to high activities in ethene polymerization and produce high molar mass polyethene (Mw up to 1100 kg/mol). Polymerization experiments reveal that the behavior of bis(amido)cyclodiphosph(III)azane-based ZrIV catalysts depends on the nature and steric bulkiness of the amido substituents, reaction temperature, MAO/zirconium ratio, as well as monomer pressure. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)

Bis(amino)cyclodiphosph(III)azanes cis-[(RNH)(PN-tBu)]2, R = 2,6-iPr2C6H3 (2), 2-tBuC6H4 (3), 2-CF3C6H4 (4), 2,5-tBu2C6H3 (5), Ph2CH (6), 2,4-Me2C6H3 (7), 2,6-Et2C6H3 (8), have been synthesized in the presence of Et3N by a nucleophilic substitution reaction of cis-(ClPN-tBu)2 (1) with the corresponding bulky aryl and alkylamines. The bis(amino)cyclodiphosph(III)azanes 2−8 adopt the thermodynamically stable cis-configuration − a prerequisite for efficient metal complex formation. Deprotonation of bis(amino)cyclodiphosph(III)azanes with nBuLi slowly afforded the corresponding salts, cis-[(2,4-Me2C6H3N)(PN-tBu)]2Li2(THF)2. The crystal structure of cis-[(2,4-Me2C6H3N)(PN-tBu)]2Li2(THF)2 (9) consists of a heterocube of two lithium atoms, two nitrogen atoms and a cyclodiphosph(III)azane ring. Transmetallation of Li compounds by TiCl4 was unselective and led to a complex mixture of products. The direct reaction of cis-bis(amino)cyclodiphosph(III)azanes with Ti(NMe2)4 is the most efficient method to prepare the corresponding titanium(IV) bis-amido complexes cis-[(RN)(PNtBu)]2Ti(NMe2)2 (11a, 12a, 14a, 15a). In the solid state, cis-[(PhN)(PN-tBu)]2Ti(NMe2)2 (11a) adopts a highly distorted trigonal-bipyramidal configuration at the metal center. These bis-amido titanium(IV) complexes have been subsequently transformed into the dichlorides cis-[(RN)(PN-tBu)]2TiCl2 (12−15) with Me3SiCl. After MAO activation the complexes possess moderate catalytic activity in ethene polymerization and produce linear polyethylene with molar masses of up to 2.6 × 106 g/mol and with narrow polydispersities. The catalytic activity and polymer properties depend strongly on the bulkiness of the ligand substituents; cis-[(2,6-iPr2C6H3N)(PN-tBu)]2TiCl2 (14) gave the highest activity (231 kg PE/molcat × bar × h). (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)

Treatment of the substituted (diarylphosphanyl)methyl group-4 metallocene complexes [(C5H4−CR1R2−PAr2)2ZrCl2] (2: R1/R2 = CH3/CH3, H/CH3, H/aryl) with Li[B(C6F5)4] in dichloromethane solution results in chloride ligand abstraction (with LiCl precipitation) to yield the complexes [(C5H4−CR1R2−PAr2)2Zr−Cl+] (5), with both phosphanyl groups internally coordinated to the metal centre. Three possible diastereoisomers are observed in the case of 5c (R1 = H; R2 = CH3), while bulkier R2 substituents give higher selectivities. The thermally induced (reversible) cleavage of the Zr−phosphane linkage results in dynamic NMR behaviour. Gibbs activation energies of ΔG≠(298 K) = 14.8 ± 0.5 and 14.5 ± 0.5 kcal/mol were obtained for these intramolecular equilibration processes in the complexes trans-5d (R1 = H; R2 = Ph) and trans-5e (R1 = H; R2 = ferrocenyl), respectively. Treatment of the substituted (dimethylamino)methyl metallocene complexes [(C5H4−CR1R2−NMe2)2ZrCl2] (6a, 6b) with Li[B(C6F5)4] proceeds analogously to yield the cation systems [{C5H4−C(CH3)2−NMe2}2ZrCl+] (12a) and [{C5H4−CH(CH3)−NMe2}2ZrCl+] (12b, three possible diastereoisomers). Both complexes have their pairs of amino groups coordinated to the metal centre. The complexes exhibit dynamic NMR spectra. Selective equilibration of the diastereotopic N(CH3)A(CH3)B resonances of complex 12a is observed [ΔG≠(233 K) = 11.5 ± 0.2 kcal/mol], whereas the adjacent C(CH3)A(CH3)B methyl groups remain diastereotopic. The dynamic equilibration of the latter was observed at a markedly higher temperature [ΔG≠(333 K) = 17.3 ± 0.2 kcal/mol]. Treatment of [{C5H4−C(CH3)2−NMe2}CpZrCl2] (10) with Li[B(C6F5)4] resulted in the formation of complex [{C5H4−C(CH3)2−NMe2}CpZr−Cl+] (11), which shows the internal −N(CH3)A(CH)B equilibration proceeding with a markedly higher activation barrier [ΔG≠(333 K) = 17.6 ± 0.2 kcal/mol] than in 12a, and a stereochemical memory effect indicative of solvent coordination to the metal centre of the resulting highly electrophilic chlorozirconocene cation intermediate. Complex 11 was characterised by an X-ray crystal structure analysis, which shows the internal Zramine coordination. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)

Phosphanyl-substituted cyclopentadienes of the type [RnCp−PR(NR1R2/Cl)] (1−22) (R = Alk, Ar; R1, R2 = H, Alk, Ar, SiR3; RnCp = tBuCp, Me4Cp, Ind, Me6Ind, Flu) can be synthesised by reaction of alkyldichlorophosphanes and alkyl(amino)chlorophosphanes with alkali metal cyclopentadienides. The method used is a general one and provides high isolated yields of the target compounds. The phosphanylcyclopentadienes can easily be deprotonated by strong bases (e.g. nBuLi, PhCH2K, Ph2CHK) and the potassium salts [RnCp−PR(NR1R2)]K (25−28) are efficiently transmetallated by Me3SnCl. A subsequent reaction with TiCl4(L)2 and ZrCl4(L)2 (L = THF, tetrahydrothiophene, Me3P) affords new half-sandwich complexes [{Me4Cp−PtBu(NEt2)}TiCl3] (36), [{Me4Cp−PtBu(NEt2)}TiCl3] (37) and [{tBuCp−PtBu(NEt2)}TiCl3] (38) in moderate yields. The reaction of [tBuCp−PtBu(Cl)] (6) with TiCl4 in the presence of Et3N at low temperature yields the half-sandwich complex [{tBuCp−PtBu(Cl)}TiCl3] (39) quantitatively; [(Cp−PtBu(Cl)]2CMe2] (11) reacts similarly and gives, dependent on the reagent ratio, either the homobimetallic derivative [{(Cp−PtBu(Cl)2CMe2}{TiCl3}2] (40) (1:2 ratio) or the ansa complex [{(Cp−PtBu(Cl)]2CMe2}TiCl2] (41) (1:1 ratio). The scope of this reaction could not be extended to sterically more demanding cyclopentadienyl derivatives. Treatment of [{tBuCp−PtBu(Cl)}TiCl3] (39) by LiN(H)tBu in the presence of Et3N leads to the formation of the constrained geometry complex [{tBuCp−PtBu(NtBu)}TiCl2] (42) in a high yield. All synthesised compounds were characterised by NMR spectroscopy, mass spectrometry and elemental analyses. The crystal structures of the ligand precursor [Me6Ind−PtBu(NHtBu)] (15) and that of [{Me4Cp−PtBu(NEt2)}TiCl3] (36) have been determined by X-ray diffractometry. The complexes described in this work are active in the MAO-mediated polymerisation of ethylene.

Transient currents were measured by the time-of-flight technique in films of aromatic polyimides based on 9,10-bis(p-aminophenyl)anthracene and a series of diimide fragments. The electric field and temperature dependences of the hole and electron drift mobilities were detected. In amorphous films of the soluble polyimide with a phthalide group in the diimide fragment, the drift mobility was found to reach the value of 10-4cm2V-1s-1 at 5·5×105Vcm-1 and 291K. In the insoluble polyimide films including the crystalline phase, the mobility was lower by one or two orders of magnitude. This is attributed to the presence of cavities in the films of the insoluble polyimides. The applicability of known theoretical models describing temperature and electric field dependences of the drift mobility is discussed. © 1998 Society of Chemical Industry

Melts of aromatic carboxylic acids are found to be excellent reaction media for 1-pot high molecular weight polyimide synthesis from diamines and tetracarboxylic acid dianhydrides. No reversible reaction of polyamic acids (PAA) formation was observed. The effect of the reactivity equalization was observed for low- and high reactive diamines in acid media. The intrinsic acid catalysis of the imidization reaction was shown to take place also in polycyclization of PAA in concentrated solutions in amic solvents. It is found that the dependence of relative imidization rate (% conv./ min) vs. AA/N-MP ratio for model low molecular and oligomeric amic acids (AA) in N-MP at 140-150°C possesses a sharp maximum near the molar ratio 1:1, the imidization rate at the point of the maximum being an order of magnitude higher than that for diluted solutions. A scheme is proposed which includes the opportunity of two reaction channels to occur: a usual one (I) and a catalytic one (II). In diluted solutions and in solid phase experiments with easy evacuation of volatile products, the role of catalytic channel II is low. To the contrary, in high concentrated solutions or in solid phase experiments under the conditions exluding volatile products evacuation, the catalytic channel becomes the key one. It is proposed that the catalytic reaction proceeds via the common acid catalysis mechanism, the solvent and water playing the role of co-catalysts, probably through the mechanism of ionic dissociation of AA or hydrogen- bound complex AA-solvent. It is shown that the water released in the course of solid phase imidization of phtalamic acid at 140°C under the conditions where vapaorization is impossible causes a sharp autocatalytic effect after initial 20%-conversion period to obtain entirely imidized product.

Derivatives of newly synthesized aromatic polyimides containing sulphur atoms in the backbone were studied as electron-hole-transporting and light-emitting materials for use in combination with tris(8-hydroxyquinoline)-aluminium in multilayer organic electroluminescent devices. Efficient bipolar charge transport has been revealed in the polymers. Bright electroluminescence (15 000 cd m -2 at 14V) was observed in the visible range. The possible role of intermolecular donor-acceptor interactions in the mechanism of electroluminescence is discussed.

Pulsation of the Sun with a period of P0 ≈ 160 min discovered about two decades ago, is still waiting explanation. In view of the hypothesis about its cosmological origin, and attempting to find signature of this P0 periodicity among other (short-period variable) stars, the pulsation frequencies of δ Sct stars are subjected to specific analysis. With a confidence level ≈ 3.8σ it is found that the frequency v0 = P0−1 ≈ 104 mHz, within the error limits, appears indeed to be the most “resonant” one for the total sample of 318 pulsating stars of δ Sct type (the most commensurable, or “synchronizing”, period for all these stars occurs to be 162 ± 4 min). We conjecture that a) the P0 oscillation might be connected with periodic fluctuations of gravity field (metrics), and b) the primary excitation mechanism of pulsations of δ Sct stars, reffected by this “ubiquitous” P0 resonance, must be attributed perhaps to superfast rotation of their inner cores (their rates tend to be in near-resonance with the “universal” v0 frequency). The arguments are given favouring a cosmoogical nature of the P0 oscillation.

C5Me4HPMe2 reacts with 1-adamantyl azide to form the firstexample of a new family of cyclopentadienylideneaminophosphorane ligands (1). Metallation of 1 with Lu(CH2SiMe3)3(THF)2 leads to the first cyclopentadienyl-phosphazene CGC 2, isolobal to known group 4 cyclopentadienyl-silylamido CGC systems. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)

Tetrafiuoroethylene (TFE) and hexafluoropropylene (HFP) were subjected to reactions with freshly distilled sulfur trioxide to obtain 1-fluorosulfonyldifluoro-acetylfluoride (FSDFAF, yield 65–70%) and pentafluoro-2-propenylfluorosulfate (PPFS, yield up to 50%). A subsequent reaction of FSDFAF with PPFS under anhydrous conditions led to a preparation of 2-(1-pentafluoro-2-propenyloxy)tetrafluoroethanesulfonyl fluoride (PPOTESF, yield 40–41%) whose structure was proved by both infrared (IR) spectroscopy and nuclear magnetic resonance (19F NMR). TFE was copolymerized with PPOTESF in bulk by using a free radical initiator of the hydrocarbon type at a temperature of 50°C. Various TFE/PPOTESF mole ratios were employed and the presence of sulfonyl fluoride (SO2F) functional groups in the copolymers was proven by IR spectroscopy. The copolymers were subjected to alkaline hydrolysis and the SO2F content was found not to exceed 0.70–0.80 mEq/g with polymer yields in the range of 11–31%. The reactivity ratios r1 and r2 related to TFE and PPOTESF, respectively, were determined by using the Fineman-Ross method. A random distribution of PPOTESF units along the polymeric chain, consisting mainly of TFE fragments, was found to exist. The copolymers had melting temperatures 40–45°C lower than polytetrafluoroethylene and were thermally stable to 305–315°C. © 1993 John Wiley & Sons, Inc.

Tetrafluoroethylene (TFE) was copolymerized with 1-fluorosulfonyl-difluoroacetylfluoride (FSDFAF) in both the bulk and solution by using a free radical initiator at temperature 50°C. The presence of sulfonyl fluoride (SO2F) functional groups in the copolymers was proved by infrared (IR) spectroscopy. The copolymers were subjected to alkaline hydrolysis followed by an acid treatment and the SO2F groups content was found not to exceed 0.40–0.50 meq/g with polymer yield ranging between 1 and 36%. Copolymerization in solution of 1,1,2-trichloro-1,2,2-trifluoroethane (Freon 113) under TFE pressure about 1.0 MPa and TFE/FSDFAF mole ratio 1.5–2.0 was proposed for further investigations. A random distribution of single FSDFAF units along the polymeric chain consisting mainly of TFE fragments was considered to exist. The copolymers had melting temperatures within 10–15°C lower than polytetrafluoroethylene and their thermal stability was 360–380°C.

Rutherford backscattering (channeling spectrometry) is employed to investigate the crystalline structure changes of surface layers and peculiarities of dopants accumulation during self-annealing As+ ion irradiation of silicon crystals. It is found that radiation of silicon by ion beams with high current densities (≈ 200 μA/em2) results in an anomalous redistribution of the impurities towards the depth of the crystal. The most probable mechanism of As redistribution which allows to describe qualitatively the observed picture is diffusion of the impurities by means of the inverse Kirkendall effect. [Russian Text Ignored].

Structural changes of chlorite, berthierine, biotite were investigated under hydrothermal conditions at pH2O = 100 MPa (1 kbar), T = 200–600 °C, run over 3 days with additions of AsS, NaCl, dolomite. The synthesis of pyrrhotine and arsenopyrite was detected at the expense of extraction of Fe from the structures of transforming layer silicates. The degree of the removal of Fe with the formation of sulphides depends on its being blocked up by a silicate surrounding. It grows in the sequence biotite-chlorite-berthierine.

An investigation is made of the mechanism of photoconductivity of needle-shaped single crystals of a weak charge transfer complex formed by anthracene and dimethylpyromellitimide. In the crystals of the charge transfer (CT) complex, the annihilation of triplet excitons is shown to generate charge carriers. The contribution of this process to the photoconductivity is evaluated. The photoconductivity of the CT-complexes is found to exhibit a sensitivity toward weak external magnetic fields as a result of the variations in the rate constants of triplet-triplet annihilation and intersystem crossing in excited states of the CT-complex. A scheme is proposed to represent the processes involving excited and ionized states in the crystals of the anthracene-dimethylpyro-mellitimide CT-complex.

In weathering crusts, sedimentary rocks and zones of hydrothermal transformation frequently mixed-layer illite-montmorillonite will occur. Based upon new experimental transformations of montmorillonite and beidellite under hydrothermal conditions in the presence of potassium chloride it is shown that mixed-layer illite-montmorillonite, with decreasing expandable proportion, occurs in the form of transitional stages of the montmorillonite illite transformation. Besides the increase of reaction temperature or potassium concentration, it is first of all an increased charge of the (Si, Al)O4 tetrahedral layers of the dioctahedral smectites that contribute considerably to accelerating the formation of illite-montmorillonite mixed-layers, lowering their expandable proportion and converting these mixed layers to illite. [Russian Text Ignored.]

Angaben uber die hydrothermale Bearbeitung von Kaolinit (pH2O = 900 kg cm−2, T = 200–500 °C) in Gegenwart der Chloride von K, Na, Ca, Mg. Die rontgenographische Analyse der erhaltenen Produkte ergab die Bildung von Phasengemischen, die mit denen in der Natur beobachteten ubereinstimmen. Zusatze von K- und Na-Chlorid fuhren zur Umbildung der kaolinitischen Struktur in die des Glimmers uber dazwischenliegende ungeordnete Mischphasen von Glimmer-Montmorillonit. Zusatze von Ca- und Mg-Chlorid bewirken die Umbildung von Kaolinit uber montmorillonitische Zwischenphasen in die bestandigen Gemische: Montmorillonit – Glimmer(Ca) und Montmorillonit–Chlorit(Mg). Der tatsachliche Ablauf der Umbildung der Schichtsilikate erfolgt im festem Zustand und besitzt Umwandlungscharakter. Man kann annehmen, das die Tendenz zur Umwandlungsumbildungscharakter. Man kann annehmen, das die Tendenz zur Umwandlungsumbildung bevorzugt auftritt und sich im Verlaufe naturlicher epigenetischer und hydrothermaler Prozesse die Schichtsilikate verandern. [Russian Text Ignored]

The regularities of transformations of layer silicates under hydrothermal conditions have been examined. For solid phases reactions (transformation of AlSi layer silicates, reactions in AlSi gels) the main factors that control the formation of alumosilicates besides PT-pH are the presence of admixtures of alkali and alkaliearth cations, likewise the presence of AlIV in the starting materials. The increasing of T and decreasing of P also promotes the preferred formation of layer alumosilicates than silicates of Al. For the reactions that pass through the dissolution of components the leading factor (under PTX = const) is the pH of the surrounding. In acid surrounding silicates with AlVI are formed and in alkaline conditions such phases, in which Al is an analog of silicon and supplies the tetrahedral positions. The results have significance for comprehend geological processes which take place in zones of hydrothermal alterations, of epigenesis and low-grade metamorphism likewise for comparison of experimental studies.

Experimentell wurde eine Strukturanderung der Tonminerale Kaolinit, Halloysit und Montmorillonit in Abhangigkeit von der Art des Druckes bei verschiedenen Temperaturen festgestellt. Bei gut geordnetem Kaolinit bemerkt man unter dem Einflus eines Stresses (100–2300 kg/cm2) eine Vergroserung der Gitterstorungen, die sich in einer Verschiebung der Schichtpakete langs der c-Achse, wahrscheinlich um c/3 ausert. Ein kleiner hydrostatischer Wasserdampfdruck (100–500 kg/cm2) bei einer Temperatur von 100–300 °C verbessert vorubergehend den Kristallinitatsgrad von Proben ungeordneten Kaolinits. Der Einflus eines quasihydrostatischen Drucks (1150–17000 kg/cm2) auf die Struktur von Tonmineralen ist typisch fur Bedingungen der oberen Horizonte der Erdkruste, die hauptsachlich durch das Vorhandensein einer Streskomponente bestimmt werden. Der Einflus ausert sich in der Erhohung des Storungsgrades der Schichtstrukturen und hangt mit ihren kristallchemischen Besonderheiten zusammen. So verwandelt sich ein gut geordneter Kaolinit in einen nach der c-Achse ungeordneten, ahnlich wie man das bei Einwirkung eines eigentlichen Stresdruckes beobachten konnte. Die Anderung der ungeordneten in a c quellfahigen Minerale Montmorillonit und Halloysit durch Druck und Temperatur ausert sich hauptsachlich in einer Neuverteilung der zwischen den Schichtpaketen liegenden Substanz, insbesonders des H2O. Die angefuhrten experimentellen Daten stimmen gut mit der Existenz von gestorten Tonmineralen in der Natur uberein. Diese Daten sind verwendbar bei der Interpretation des Verhaltens der Strukturen von Tonmineralen sedimentarer Bildung unter den Bedingungen der Epigenese und der anfanglichen Metamorphose. [Russian Text Ignored].

In the earlier papers (I and II, Frank-Kamenetzkij et al., 1966, 1968) data regarding the structural and facial changes in kaolin group minerals under conditions of interaction with hydrothermal chloride solutions of K, Na, Ca, Mg at P = 900 kg cm−2. T = 200–500°C were dis- cussed. In the present paper the results of these investigations are summed up. The diffractometrical, electronographic and electron microscopic investigations of initial, intermedial and final phasis mainly of layered silicate and aluminous silicates show a cristallographic inheritance of structures during the transformation of kaolinite into montmorillonite, micas and mixed layered facies (rectorit, tosudit etc.) This is seen in the retention of the main features in the basal plane, in the character of population of the octahedral positions, in the tendency to retain the sequence of alternation and imposition of layers (polytype), and in the processes of deformation that the structures of the initial minerals undergo during such changes. The wide participation of ordered and disordered mixed-layered structures in these reactions is the result of structural changes by transformatical means. At the same time, the chemical nature of the medium exerts considerable influence on the course and nature of the resulting structures. Thus, the mechanism of transformational thermal changes of aluminium silicates, which is already known for “dry-systems”, is observed to a great extent in the case of complex polycomponental systems under H2O pressure and is characterised by the specific individual features discussed in this paper. [Russian text ignored].

Tetrafluoroethylene was prepared by a thermal depolymerization of poly(tetrafluoroethylene) waste. The gaseous mixture containing 95–97 % tetrafluoroethylene has been used without further purification in a direct reaction with iodine to synthesize some α,ω-diiodoperfluoroalkanes at temperature 285±5°C for 8 h. Stoichiometric one to one ratio of the reagents has been found to produce higher diiodoperfluoroalkanes yield per unit reaction volume than synthesis in the presence of an excess of tetrafluoroethylene. This approach provides a rapid one-pot procedure to these valuable reagents without any dangerous step.