Additive prediction of thermodynamic functions of hydrofluorides

Summary The experimental data available on the thermodynamic functions ⁰ forMF·nHF hydrofluorides [M=Li, Na, K, Rb, Cs, NH₄, Ag(I) and Tl(I);n=1–3] have been evaluated additively. The unknown values of ⁰ forn=0÷7 are predicted.

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Additive Voraussagen der thermodynamischen Funktionen von Hydrogenfluoriden (Kurze Mitt.)

Zusammenfassung Die vorhandenen experimentellen Daten über die thermodynamischen Funktionen ⁰ von HydrogenfluoridenMF·nHF [M=Li, Na, K, Rb, Cs, NH₄, Ag(I) und Tl(I);n=1–3] werden linear ausgeglichen und die fehlendenden Werte für ⁰ mitn=0÷7 vorausgesagt.

     

Study on the Melting Process of Nitrocellulose by Thermal Analysis Method

The melting process of NC is studied by using modulated differential scanning calorimetry (MDSC) technique, the microscope carrier method for measuring the melting point and the simultaneous device of the solid reaction cell in situ/RSFT-IR. The results show that the endothermic process in the MDSC curve is reversible. It is caused by the phase change from solid to liquid of the mixture of initial NC, decomposition partly into condensed phase products. The values of the melting point, melting enthalpy (H_m), melting entropy (S_m), the enthalpy of decomposition (H_dec) and the heat-temperature quotient (S_dec) obtained by the MDSC curve of NC at a heating rate of 10 K min^–1 are 476.84 K, 205.6 J g^–1, 0.4312 J g^–1 K^–1, –2475.0 J g^–1 and –5.242 Jg^–1K^–1, respectively. The MDSC results of NC with different nitrogen contents show that with increasing the nitrogen content in NC, the absolute values of H_m, S_m, H_dec and S_dec increase.This revised version was published online in November 2005 with corrections to the Cover Date.     

Heat capacities of aqueous perchloric acid and sodium perchlorate at 298°K: ΔC p o of ionization of water

We have used a Picker flow calorimeter for measurements leading to apparent molal heat capacities of dilute aqueous solutions of HClO₄ and NaClO₄ at 298°K. Results have been used to derive _c ^° =–27.1J-°K ^–1-mole ^–1 for HClO₄ (aq.), _c ^° =15.2J-°K ^–1-mole ^–1 for NaClO₄ (aq.), and C _p=–213.₈J-°K^–1-mole^–1 for ionization of water.     

Komplexe des zweiwertigen Molybdäns,Derivate des Oktahalodimolybdat(II)-Ions, 4. Mitt.: Darstellungen und Kristallstrukturen von zwei neutralen Komplexen mit 4-Methylpyridin

Mo₂Cl₄ Pic ₄·CHCl₃ (A) (Pic=4-methylpyridine) and Mo₂Br₄ Pic ₄ (B) crystallize in the monoclinic space group.A inC2/c (No. 15) witha=15.175 (4),b=10.847 (2),c=19.946 (6) and =104.52 (2)°;D _o=1.71 (2),D _c =1.72 gcm^–3 forZ=4.B inP2_l/n (No. 14) witha=9.270 (3),b=16.614 (5),c=9.305 (3) and =91.96 (5)°;D _o=2.03 (3),D _c =2.05 gcm^–3 forZ=2.Two halogens and 4-methylpyridines of the MoX ₂ Pic ₂ group are in the trans position. Mo–Mo bond lengths are 2.153 96) forA and 2.150 92) forB. Both molecules are situated on the inversion center resulting in the eclipsed configuration of the ligands around the molybdenum pair. The structure ofB has been refined to the conventionalR factors of 0.08 and 0.098. Disorder on the part of 4-methylpyridines and chloroform molecules stopped the refinement ofA at the endR value of 0.175.Mean Mo–X and Mo–N bonding distances are 2.40 (2), 2.25 (5) forA and 2.53 (3), 2.25 (1) forB.

     

Extraction of sodium picrate into nitrobenzene in the presence of dicyclohexyl-18-crown-6

From extraction experiments and -activity measurements, the extraction constant corresponding to the equilibrium Na⁺(aq)+A^–(aq)+L(nb)NaL⁺(nb)+A^–(nb) taking place in the two-phase water-nitrobenzene system (A^–=picrate, L= dicyclohexyl-18-crown-6; aq-aqueous phase, nb=nitrobenzene phase) was evaluated as logK _ex(NaL⁺, A^–)=2.6.Further, the stability constant of the dicyclohexyl-18-crown-6-sodium complex in nitrobenzene saturated with water was calculated: _nb(NaL⁺)=7.8.     

Crystal Structures of Two New Holmium Polysulfides in the Series of Rare-Earth Polychalcogenides

The crystal structures of two polysulfide phases HoS_1.885(5) (I) and HoS_1.863(8) (II) were determined; the integer stoichiometric ratio was found to be Ho₈S₁₅. The data were collected on an Enraf-Nonius CAD-4 automatic diffractometer using the standard procedure (MoK, graphite monochromator, an absorption correction applied based on -scan data). Crystal I: space group P4/nmm, a = 3.820(1), c = 7.840(3) , V = 114.40(6) ³, Z = 2 for the composition HoS_1.885(5), d _calc = 6.542 g/cm³, R = 0.0520 for 184 unique reflections with I_hkl > 2 _I; crystal II: space group P2₁/m, a = 10.961(2), b = 11.465(2), c = 10.984(2) , = 91.27(3)°, V = 1380.0(4) ³, Z = 24 for the composition HoS_1.863(8), d _calc = 6.486 g/cm³, R = 0.0596 for 5354 unique reflections with I_hkl > 2 _I. In both compounds, the Ho atoms are surrounded by 9 (8+1 for three atoms in II) S atoms forming monocapped square antiprisms. The Ho–S distances vary from 2.717 to 3.067 irrespective of the type of ion [S^2– or (S₂)^2–]; the maximal distance to the atoms completing the coordination is 3.684 . The compounds have PbFCl type structures composed of ...(S₂)^2–...Ho³⁺...S^2–...S^2–...Ho³⁺...(S₂)^2–... layer packets differently oriented in space relative to the unit cell axes. The S^2–...S^2– and S^2–...(S₂)^2– interlayer distances are mostly shorter than the sum of the ionic radii and vary within the limits of 3.331-3.558 and 3.029-3.784 for the first and second types, respectively. For I, the calculated site occupancies and densities are given depending on the composition Ho-S_2-x (x = 0.25-0); for II, the most probable formulas of rational compositions in the same range of x are presented.     

Spectrophotometric determination of mercury with 5,10,15,20-tetrakis(3-chloro-4-sulfophenyl)porphine by flow injection analysis

5,10,15,20-tetrakis(3-chloro-4-sulfophenyl)porphine (m-Cl-TPPS₄) was synthesized and used for the Spectrophotometric determination of mercury by flow injection analysis. A pseudo-first-order reaction kinetic mechanism was proposed with a rate constant of 0.8 min^–1 for Hg(II) withm-Cl-TPPS₄ in the presence of 8-hydroxyquinoline in a medium of 1.0M acetic acid and sodium acetate buffer solution (pH 6.22). In the optimum conditions of reaction temperature (85 ° C), stopped-flow time (60 s) and sampling volume (100 l), the method's relative standard deviation was 0.82% (n = 12) at 5.0 g ml^–1 mercury, with a linear range of 0–12.0 g ml^–1 and an analytical frequency of 60h^–1. The detection limit (3) was 0.025 g ml^–1. Interference studies showed that most metal ions co-existing with Hg²⁺ could be tolerated at 100-fold excess levels, but Zn²⁺, Cu²⁺ and Mn²⁺ needed to be masked. The method has been applied to the analysis of water samples with satisfactory results.     

Tetracarbonyliron adducts of Cp2Cr2(CO)4(μ-η2-P2). Syntheses and crystal structures of Cp2Cr2(CO)4P2[Fe(CO)4] m (m=1 and 2)

Cp₂Cr₂(CO)₄( - ² - P₂), 1, reacts with one molar equivalent of Fe₂(CO)₉ in THF to yield the mono- and di-iron complexes, Cp₂Cr₂(CO)₄P₂[Fe(CO)₄], 2, (16.5% yield) and Cp₂Cr₂(CO)₄P₂[Fe(CO)₄]₂, 3, (16.9% yield), as dark magenta brown and dark greenish brown crystals, respectively. Both complexes were characterized by single-crystal X-ray diffraction analysis. Crystal data –2: space group =P2₁/c,a=17.024(1) Å,b=8.180(1) Å,c=30.891(2) Å, =100.953(5)°,V=4223.4(7)ų,Z=8, 3743 observed reflections,R _F=0.033; 3: space group P1,a=10.209(2) Å,b=10.212(2) Å,c=15.989(3) Å, =106.93(1)°, =91.87(1)°, =119.50(1)°,V=1356.5(4) ų,Z=2, 3489 observed reflections,R _F=0.029.     

Study of the non-adiabatic transitions with application to NO

An expression for the non-adiabatic transition probability is derived from the viewpoint of the non-stationary character of the adiabatic approximation. A numerical calculation has been made for the free NO molecule. The non-adiabatic transition probability for the transition (B ² =0)(a ⁴ =9) is estimated to be 10^–6 sec^–1 by using the wave functions proposed by Moser et al.

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Zusammenfassung Für die nicht adiabatische Übergangswahrscheinlichkeit wurde aus dem nicht-stationären Charakter der adiabatischen Näherung ein Ausdruck hergeleitet, der für den Fall des NO-Moleküls numerisch ausgewertet wurde. Dabei ergab sich unter Verwendung der Wellenfunktionen von Moser u. Mitarb. eine Wahrscheinlichkeit für den Übergang (B ² =0) (a ⁴ =9) von der Größenordnung von 10^–6 sec^–1.

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Résumé Une expression pour la probabilité de la transition non adiabatique est obtenue du point de vue du caractère non stationnaire de l'approximation adiabatique. Un calcul numérique a été effectué pour la molécule NO isolée. La probabilité de transition non adiabatique pour la transition (B ² =0)(a ⁴ =9) est évaluée à 10^–6 sec^–1 en utilisant les fonctions d'onde proposées par Moser et al.

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This work was supported by The Faculty Grant of Arizona State University.     

Ein neuer Typ quaternärer Oxometallate: K3Na2[InO4]

With K₃Na₂[InO₄] the first example of new kind of oxides of the type A₃A₂[MO₄] with R(A)>R(A) was prepared in form of colourless single crystals by oxidation of the intermetallic compound KNaIn₂. Intimate mixtures of the educts (K₂O₂: K_0.5Na_0.5In=1.2:1) were heated in sealed Ag-tubes (380 °C, 2 d, then 480 °C, 5 d). K₃Na₂[InO₄] crystallizes monoclinic (P2₁/n) witha=1012.6 pm,b=969.9 pm,c=725.4 pm, =91.02°;Z=4. The crystal structure was elucidated by four-circle diffractometer (PW 1100, Ag-K, 6047I _o(hkl),R=7.3%,R _w=4.4%). The new typ forms a very complicated 3-dimensional network ³ {Na₂InO₄} stuffed by 3 K⁺. The Madelung part of lattice energy, MAPLE, is calculated and discussed.

Professor Edwin Hengge zum 60. Geburtstag am 21. Juli 1990 gewidmet     

The kinetics of base hydrolysis of [Co(trien)(amine)Cl]2+ complexes (amine=imidazole,pyridine,n-butylamine and 2,2-dimethoxyethylamine)

Summary The complexescis--[Co(trien)(ImH)Cl]²⁺ (ImH=imidazole, trien=1,8-diamino-3,6-diazaoctane),cis--[Co(trien)(Buⁿ-NH₂)Cl^–]²⁺,cis--[Co(trien)(NH₂CH₂-CH(OMe)₂)Cl^–]²⁺ andcis-₂-[Co(trien)(py)Cl]²⁺ (py=pyridine) have been characterised and their kinetics of base hydrolysis studied. Thecis--isomers which have afac-fac arrangement of the trien ligand have values of k _OH ²⁵ in the 73 to 253 dm³ mol^–1 s^–1 range at I=0.1 mol dm^–3. Extremely rapid base hydrolysis is observed withcis-₂-[Co(trien)(py)Cl]²⁺ where k _OH ²⁵ is 6.65×10⁶ mol³ mol^–1 s^–1 at I=0.1 mol dm^–3. This complex has amer-fac arrangement of the trien ligand with flatsec-NH donor leading to rapid base hydrolysis due to good -overlap between the conjugate base and cobalt(III). The pyridine ligand causes aca. 30 fold rate increase compared with the hydrolysis ofcis-₂-[Co(trien)(NH₃)Cl]²⁺.     

Augmentation of the Generalised n×n Eigenvalue Equation to a Generalised (n+1)×(n+1) Eigenvalue Equation

Generalised n×n eigenvalue equation B| _i = _i S ^b | _i (i=1,...,n) where B and S ^b are n×n Hermitian matrices while S ^b is in addition positive definite is considered. This equation is augmented to a generalised (n+1)(n+1) eigenvalue equation H| _k = _k S| _k (k=1,...,n+1) where Hermitian matrices H and S represent matrices B and S ^b , respectively, augmented by one additional row and one additional column. It is shown how the eigenvalues _k and the eigenvectors | _k of the augmented eigenvalue equation can be expressed in terms of the eigenvalues _i and the eigenvectors | _i of the original eigenvalue equation. Operation count to obtain by this method all augmented eigenvalues and eigenvectors is of the order O(n ²). Unless matrices involved are of some special kind such as sparse matrices or alike, this operation count is one order of magnitude smaller than operation count required by other presently known methods. In many practical cases operation count to obtain a single selected eigenvalue and/or eigenvector by this method is of the order O(n). In the case of the generalised eigenvalue equation, all other methods usually require again O(n ³) operations, even if only a single eigenvalue and/or eigenvector is required. Thus in many cases of interest operation count to obtain a selected eigenvalue and/or eigenvector by this method is two orders of magnitude smaller than operation count required by other methods.     

The phenomenon of conglomerate crystallization in coordination compounds. XXIII: The crystallization behavior of [cis-Co(en)2(N3)(SO3)] · 2H2O (I) and of [cis-Co(en)2(NO2)(SO3)] · H2O (II)

A room temperature water solution of (I) crystallizes as a racemate, space groupP2 ₁/n with lattice constantsa=7.737(6),b=10.694(5),c=15.097(6) Å, and=102.83(5)°;V=1218.05 ų andd (calc; M.W.=337.24, Z=4) = 1.642 g cm^–3. A total of 2381 data were collected over the range 4° 2 < 50°; of these, 1452 (independent and withI 3(I)) were used in the structural analysis. Data were corrected for absorption ( = 15.76 cm^–1), and the relative transmission coefficients ranged from 0.8976 to 0.9984. Refinement led to the finalR(F) andR _w(F) residuals of 0.0858 and 0.1116. A room temperature water solution of (II) crystallizes as a racemate in space group P2₁/c with lattice constantsa=6.638(3),b=11.425(8),c=15.147(16) Å, and=93.27(6)°; F=1146.8 Å andd (calc; M.W.=323.2,Z=4) = 1.872 g cm^–3. A total of 2200 data were collected over the range 4° 2 < 50°; of these, 1918 (independent and withI 3(I)) were used in the structural analysis. Data were corrected for absorption (=16.94 cm^–1), and the relative transmission coefficients ranged from 0.9049 to 0.9967. Refinement led to the finalR(F) andR _w(F) residuals of 0.0231 and 0.0279. The chirality symbol for the particular enantiomer of (I) refined here is (), while for (II) the chirality symbol is (), which means that in the latter compound one of the en rings is in a higher energy conformation. We attribute this result to competitive intramolecular hydrogen-bonded interactions between the — NH₂ hydrogens of the en ligands and the oxygens of the -NO₂ and -SO₃ ligands, strengths which are enhanced by coercing a change in sign of the torsional angle of one en ringa motion which permits both oxo ligands to form stronger hydrogen bonds while retaining proper O O contacts. This phenomenon is not observed in (I) since the azide ligand does not compete with -SO₃ for such hydrogen-bonded interactions, and nonbonded pair repulsions can be minimized without affecting the ability of — SO₃ oxygens to form strong intramolecular hydrogen bonds.     

Empirical equations of state for adsorption layer: Alkylthiopolyoxyethylene glycols

Surface tension isotherms ofn-alkylthiopolyoxyerhylene glycols:n-C _x H_2x+1S(CH₂CH₂O) _y H, wherex=5 to 8,y=3 or 4, were approximated with orthogonal polynomials to get good quality values of surface pressure (II) and molar area of the adsorbed layer (). The modified Volmer (*(–₀)=Z*R*T) van der Waals and virial equations of state were used to correlate and in terms of real two-dimensional gas. The combination of Volmer and van der Waals equations of state made it possible to determine the interaction energy, , which was prescribed to cohesion of hydrophobic chains in the adsorption layer. The value of for the amphiphiles in question was in the range 0.97–1.91R*T and the average contribution per methylene group was ca. 0.21R*T.The Lennard-Jones potentials calculated from second virial coefficient were of the same range as , but no clear relation was found between their values and number of structure elements of the alkylthiopolyoxyethlene glycols.Presented during 7th International Conference: Surface and Colloid Science, July 7–13, 1991, Compiegne, France     

Über den Einfluß von Ionen auf die Wasserstruktur

Zusammenfassung Wäßrige Lösungen von Elektrolyten, deren Kation und Anion strukturbrechend gegenüber dem Wasser wirken, können in bestimmten Temperaturbereichen eine relative Viskosität _re1= /_o < 1 besitzen. Charakteristisch ist aber, daß man an solchen Elektrolytlösungen stets einen positiven Temperaturkoeffizienten der relativen Viskositätd _rel/dT feststellt, da hier mit steigender Temperatur die Struktur des Wassers weniger abgebaut wird als in reinem Wasser. Dies ist verständlich, weil unter dem strukturbrechenden Einfluß dieser Ionen die Wasserstruktur bereits stärker abgebaut, die Beweglichkeit der Wassermolekeln also höher ist als im Wasser selbst bei gleicher Temperatur.Das entgegengesetzte gilt für Lösungen von Elektrolyten mit strukturbildendem Kation und Anion.Hier istd _rel/ldT bis zu den höchsten Konzentrationen, bei denen nur noch die primären Hydrathüllen der Ionen vorliegen, negativ, da die Wassermolekeln eine erhöhte Ordnung und somit eine geringere Beweglichkeit als im reinen Wasser haben.Da in den Lösungen mit strukturbrechendem Kation und Aniond _rel/dT auch bei Konzentrationen bis zu 14 molal zunehmend positiv wird, bedeutet das, daß unter dem Einfluß dieser Ionen die Beweglichkeit der Wassermolekeln auch an der Ionenoberfläche gegenüber dem reinen Wasser erhöht ist. Es ist daraus zu schließen, daß strukturbrechende Ionen keine primäre Hydrathülle aus Wassermolekeln erhöhter Ordnung und eingeschränkter Beweglichkeit aufweisen, wie vielfach postuliert wird.Zum selben Resultat kommt man, wenn man die korrigierte relative Viskosität _rel, korr, die außer der Viskosität des Lösungsmittels nur den Strukturbeitrag der Ionen enthält, ermittelt. Sie nimmt z. B. bei Guanidiniumrhodanid und -chlorid-Lösungen bis zu Konzentrationen von 6,5 bzw. 14 molal linearer mit der Konzentration ab. Auch die Aktivierungsenergie H _* ; der Viskosität läßt den Schluß zu, daß in derartigen Lösungen die der Ionenoberfläche unmittelbar benachbarten Wassermolekeln eine erhöhte Beweglichkeit gegenüber denen im reinen Wasser bei derselben Temperatur besitzen. Während H _* bei Guanidiniumsulfatlösungen auf einen Wert von 4,7 kcal/Mol gegenüber 3,98 kcal/Mol des Lösungsmittel ansteigt, fällt sie bei Guanidiniumchlorid-Lösungen bis auf 3,1 kcal/Mol ab und bleibt bis zu einer Konzentration von 14 molal konstant.

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Summary The temperature coefficientd_rel/dT of aqueous solutions of electrolytes containing structure breaking cations and anions is positive. As a consequence of the structure breaking ions within creasing temperature the water structure in such solutions decreases not to the same degree like in pure water. On the other hand by structure making ions a negatived _re1/dT is caused. In such solutionsd_rel/ldT is negative up to the highest concentrations because of the increasing mobility of ordered water molecules near this type of ions. Therefore the positive values ofd_rel/dT up the highest concentrations of structure breaking electrolytes — e. g. 14 molal guanidinium-hydrochloride solutions — indicate that the mobility of the water molecules surrounding the ion surface is higher than in pure water. This means that structure breaking ions don't have a primary hydration shell of highly ordered water molecules of relatively low mobility.We can show this too by evaluating the corrected relative viscosity _rel, corr which contains only the change of viscosity caused by the ions and not the contribution of the solute to the viscosity of the solution. The value of _rel, corr decreases e.g. in the case of guanidinium thiocyanate and guanidinium-chloride up to 6,5 resp. 14 molal linearly with concentration.Furthermore the energy of activation H _* shows that water molecules in contact with the surface of structure breaking ions have all higher mobility than in pure water at the same temperature. H _* ; of guanidiniumsulfate solutions increases after an initial decrease up to 4,7 kcal/mole compared with 3,98 kcal/mole of pure water, whereas H _* ; of guanidiniumchloride solutions decreases down to 3,1 kcal/mole and remains constant up to 14 molale.

     

The multi-centre integrals of derivative,spherical GTOs

The multi-centre integrals of the orbital system ⁿ Y _lm () exp (–r ²) are evaluated using the Talmi transformation of nuclear shell theory. The integrals are simpler than those of the systems r ²ⁿ Y lm(r) exp (–r ²), x ^l y ^m z ⁿ exp (–r ²), (/x) ^l (/y) ^m (/z) ⁿ exp (–r ²) and the spherical oscillator functions. The integral types investigated are: overlap, electric dipole transition (momentum operator), kinetic energy, three-centre nuclear attraction, four-centre electronic repulsion, three-centre spin-orbit coupling, and magnetic dipole transition (three-centre integrals of the angular momentum operator).     

Characteristic of the Ag(II)/Ag(I) system in the presence of 2-pyridinecarboxylic acid in acetonitrile

Summary Formation constants of the complexes of Ag(I) with 2-pyridine-carboxylic acid (Hpic) were determined by the potentiometric method: ₀₁=36, ₀₂=537. It was shown by IR spectroscopy that the complexation of Ag(I) ions in acetonitrile proceeds without the formation of Ag-O bond and the complexes have the following forms: AgHpic ⁺ and Ag(Hpic) ₂ ⁺ . Oxidation of Ag(Hpic) ₂ ⁺ at the potential =1850 mV vs. NHE resulted in the complex Ag(Hpic) ₂ ²⁺ . The formal potentialE _f ⁰ =1.772 V vs. NHE of the system Ag(Hpic) ₂ ²⁺ +eAg(Hpic)⁺+Hpic was determined by chronovoltamperometry, while the formal potentialE _f ⁰ =1.841 V vs. NHE of the system Ag(Hpic) ₂ ²⁺ +eAg(Hpic) ₂ ⁺ was calculated. Properties of the system in water and acetonitrile were compared.

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Charakteristik des Ag(II)/Ag(I)-Systems in Gegenwart von 2-Pyridincarbonsäure in Acetonitril

Zusammenfassung Es wurden die Bildungskonstanten der Komplexe von Ag(I) mit 2-Pyridincarbonsäure (Hpic) mittels Potentiometrie bestimmt: ₀₁=36, ₀₂=537. Die IR-Spektren bewiesen, daß die Komplexierung von Ag(I)-Ionen über die Ausbildung einer Ag-O-Bindung verläuft, wobei die Komplexe die folgenden Formeln besitzen: AgHpic ⁺ und Ag(Hpic) ₂ ⁺ . Die Oxidation von Ag(Hpic) ₂ ⁺ beim Potential =1850 mV gegenüber NHE ergab den Komplex Ag(Hpic) ₂ ²⁺ . Das formale PotentialE _f ⁰ =1.772 V (gegenüber NHE) des Systems Ag(Hpic) ₂ ²⁺ +eAg(Hpic)⁺+Hpic wurde mittels Chronovoltamperometrie ermittelt, während das formale PotentialE _f ⁰ =1.841 V (gegenüber NHE) des Systems Ag(Hpic) ₂ ²⁺ +eAg(Hpic) ₂ ⁺ berechnet wurde. Außerdem wurden die Eigenschaften der Systeme in Wasser und Acetonitril verglichen.

     

Organometallic complexes containing thiosemicarbazone and related ligands. Part II(1). η3-allyl dicarbonyl complexes of molybdenum(II) with attached thiosemicarbazone ligands

Summary The -allylmolybdenum(II) complexes [MoX(CO)₂-(NCMe)₂(³-C₃H₄R)] (X=Cl, Br and I; R=H and 2-Me) react either in dichloromethane or acetonitrile with thiosemicarbazones to give the new complexes [MoX-(CO)₂(RRCNNHCSNH₂)(³-C₃H₄R)] (R=H or Me; R'=Me, Et, Pr or Ph)via displacement of acetonitrile ligands.     

The outersphere complex of EuCl2+ in a mixed system of methanol and water of 1.0M (H, Na) (Cl, ClO4)

The stability constans, ₁, of each monochloride complex of Eu(III) have been determined in the methanol and water mixed system with 1.0 mol·dm^–3 ionic strength using a solvent extraction technique. The values of ₁ increase with an increase in the mole fraction of methanol (X _S ) in the mixed solvent system when 0X _S 0.40. The, distance of Eu³⁺–Cl^– in the mixed solvent system was calculated using the Born-type equation and the Gibbs' free energy derived from ₁. Calculation of the Eu³⁺–Cl^– distance and the preferential solvation, of Eu³⁺ by water proposed the variation of the outersphere complex of EuCl²⁺ as follows: (1) [Eu(H₂O)₉]³⁺Cl^–, [Eu(H₂O)₈]³⁺Cl^– and [Eu(H₂O)₇(CH₃OH)³⁺Cl^– inX _S0.014, (2) [Eu(H₂O)₈]^3–Cl^– and [Eu(H₂O)₇(CH₃OH)]³⁺Cl^– in 0.014<X _S <0.25 and (3) [Eu(H₂O)₇(CH₃OH)]^3–Cl^– and [Eu(H₂O)₆(CH₃OH)[₂ ³⁺Cl^– in 0.25<X _S 0.40.     

Ein einfacher Weg zu α-substituierten (E)-3-Oxo-1-alkenylphosphonsäureestern

Zusammenfassung -Substituierte -Acylvinylphosphonate3 mitE-Konfiguration [R ²CO-CH=C(R ¹)-P(O)(OR)₂], werden in guten Ausbeuten durchWittig-Reaktion von Acylphosphonsäureestern1 [R ¹CO-P(O)(OR)₂,R ¹=Alkyl oder Aryl] mit (2-Oxoalkyliden)triphenylphosphoranen2 [R ²CO-CH=PPh ₃,R ²=Alkyl, O-Alkyl oder CH₂ X (X=Br, OMe, CO₂ Et)] erhalten.

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A convenient route to -substituted dialkyl (E)-3-oxo-1-alkenylphosphonates

-Substituted dialkyl (E)--acylvinylphosphonates [R ²CO-CH=C(R ¹)-P(O)(OR)₂,3], are easily obtained in good yields byWittig-reaction of dialkyl acylphosphonates1 [R ¹CO-P(O)(OR)₂,R ¹=alkyl or aryl) with 2-oxoalkylidene triphenylphosphoranes2 [R ²CO-CH=PPh ₃,R ²=alkyl, O-alkyl and CH₂ X (X=Br, OMe, CO₂ Et)].