Synthesis and Characterization of the Isocyanide Ligated Centered Zirconium Halide Cluster [(Zr6Be)Cl12(CNXyl)6]

The first isocyanide ligated hexanuclear zirconium halide cluster is reported. The unoxidized [(Zr₆Be)Cl₁₂(CNXyl)₆] (CNXyl = 2,6-dimethylphenyl isocyanide) was obtained from the solid state precursor K₃Zr₆Cl₁₅Be by dissolution in CH₃CN in the presence of CNXyl. The CNXyl ligands occupy all the axial positions on the cluster. The compound was recrystallized from CH₂Cl₂ and Et₂O. [(Zr₆Be)Cl₁₂(CNXyl)₆].2CH₂Cl₂ crystallizes in the space group (#2) with a = 12.092(5) Å, b=12.728(5) Å, c = 14.102(8) Å, = 104.98(4)°, =107.11°, = 100.94°, V = 1919(2) ų, Z = l, R = 11.3% and R _W = 27.0%. For the bound isocyanide ligands, v _CN increases to 2140 cm^–1.     

Molecular structures of benzoylbenzo-12-crown-4 and diphenylacetylbenzo-12-crown-4 and possible reasons for different conformational states of their macrocycles

The molecular structures of (benzoyl)benzo-12-crown-4 (a=22.387,b=4.503,c=16.167 Å,d _calc=1.34 g cm^–3,Z=4, space groupP2₁ nc, DAR-UM, Cu-K,R=0.056) and (diphenylacetyl)benzo-12-crown-4 (a=8.866,b=23.337,c=10.737 Å;d _calc=1.25 g cm^–3,Z=4, space groupP2₁2₁2₁, DAR-UM, Cu-K, R=0.056) have been investigated. The differences in the conformations of the macrocycles and the degree of conjugation between the benzene ring orbitals and the lone pairs on the adjacent oxygen atoms in the macrocycle are discussed.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 11, pp. 1906–1911, November, 1993.     

Crystal structure of tetraethylammonium fluoride-water (4/11), 4(C2H5)4N+F− · 11H2O,a clathrate hydrate containing linear chains of edge-sharing (H2O)4F− tetrahedra and bridging water molecules

Crystals of 4(C₂H₅)₄N⁺F^– · 11H₂O are orthorhombic, space groupPna2₁, witha=16.130(3),b=16.949(7),c=17.493(7) Å, andZ=4. The structure was shown to be a clathrate hydrate containing infinite chains of edge-sharing (H₂O)₄F^– tetrahedra extending parallel to thea axis. The chains are laterally linked by bridging water molecules to form a three-dimensional hydrogen-bonded anion/water framework. The ordered (C₂H₅)₄N⁺ cations occupy the voids in two open channel systems running in theb andc directions. FinalR _F =0.091 for 2278 observed MoK data measured at 22°C. Supplementary Data: relating to this article are deposited with the British Library as Supplementary Publication No. SUP 82010 (20 pages).Dedicated to Professor H. M. Powell.     

Novel polymer blends based on poly(ether-urethane) ionomer and ion-containing styrene copolymer

The structure-property relationships of thermoplastic polymer blends based on poly(ether-urethane) ionomer (PEUI) and ion-containing styrene-acrylic acid copolymer (S-co-AA(K)) have been investigated by using DMTA, DSC and TGA, as well as tensile tests. Convergence of the glass transition temperature (T_g) values of the PEUI and the S-co-AA(K) components in the blends studied, as compared to the individual polymers, was found and explained by improving compatibility of the components due to increasing effective density of physical networks formed by ion-dipole and ion-ion interactions of ionic groups of the components. Character of E'=f(T) and E'=f(T) dependencies confirms the increase of the effective density of physical networks in the compositions studied compared to individual PEUI and S-co-AA(K). Improvement of end-use properties, i.e. thermal stability and tensile properties has been found for the PEUI/S-co-AA(K) compositions with lower content of S-co-AA(K) (i.e. <10 mass%) and explained by formation of additional network of intermolecular ionic bonds between the functional groups of PEUI and S-co-AA(K).     

Synthesis of 1-triphenylgermylpropiono-4-substituted semicarbazides,thiosemicarbazides and their heterocyclic derivatives

Twenty-one new organogermanium compounds with the formulae Ph₃GeCHR¹CH₂CONHNHC(X)NHR² (1) (R¹=H, Ph; = Ph, p-CH₃Ph, O -CH₃Ph, p-ClPh, COPh, X = S, O) and (R¹ = H, Ph; R² = Ph, p-CH₃Ph, o-CH₃Ph, p-ClPh; X=S, O) were synthesized and characterized by elemental analysis, ¹H NMR, IR, MS and X-ray diffraction techniques. Compounds l were prepared by the reactions of Ph₃GeCHR¹CH₂CONHNH₂ with R²NCX in chloroform in 77-94% yields, and 2 were obtained by refluxing l with sodium hydroxide (8%) with yields of 55-94%.     

Li2H4I2O10, das erste Tetrahydrogendimesoperiodat

Li₂H₄I₂O₁₀, the First Tetrahydrogendimesoperiodate Li₂H₄I₂O₁₀ has been obtained as an intermediate during the dehydration of LiH₄IO₆ · H₂O to LiIO₄, for the first time. According to the results of an X-ray structure determination (monoclinic, P2₁/n, a = 533.98(4), b = 471.85(4), c = 1431.48(10) pm, β = 91.614(7)°, Z = 2, 726 diffractometer data, R = 0.056), Li₂H₄I₂O₁₀ contains the previously unknown tetrahydrogendimesoperiodate ion H₄I₂O₁₀^2?, consisting of two edge-shared IO₆ octahedra. They are connected with LiO₆ octahedra via common edges and vertices. The crystals are non-merohedrally twinned along (100).     

Tetrakis(2-fluorophenylamino)silan und sein erstes Kondensationsprodukt N-(2-fluorophenyl)-Si,Si, Si,Si′, Si′, Si′-hexakis(2-fluorophenylamino)-disilazan. Synthesen und Kristallstrukturen

Zusammenfassung Tetrakis(2-fluorophenylamino)silan (1) wurde als Precursor zur Darstellung poröser, nitridischer Festkörper synthetisiert und mit Hilfe der Einkristallröntgenstrukturanalyse charakterisiert (C2/c;a=16.771(7) Å,b=16.827(5) Å,c=16.753(6) Å, ß=111.00(2)°,z=8). Beim Erhitzen mit Ammoniumcarbamat als Katalysator wurde N-(2-fluorophenyl)-Si, Si, Si, Si, Si, Si, -hexakis(2-fluorophenylamino)disilazan (2) als erstes Kondensationsprodukt isoliert ( ;a=9.331(1) Å,b=13.698(5) Å,c=16.164(4) Å, =90.34(2)°, ß=103.03(2), =103.04(3)°, Z=2).

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Tetrakis(2-fluorophenylamino)silane and its first product of condensation N-(2-fluorophenyl-Si, Si, Si, Si, Si, Si-hexakis(2-fluorophenylamino)disilazane. Syntheses and crystal structures

Summary The synthesis and crystal structure determination of silanetetramine N,N,N,N2-fluorophenyl(C2/c;a=16.771(7) Å,b=16.827(5) Å,c=16.753(6) Å, ß=111.00(2)°, z=8) are reported. In a search for suitable condensation pathways to silicon/nitrogen based porous solids, N-(2-fluorophenyl)-Si,Si,Si,Si,Si,Si-hexakis(2-fluorophenylamino)disilazane (2) has been obtained from the ammonium carbamate catalyzed condensation of the silanetetramine in teflon lined autoclaves. The X-ray crystal structure determination ( ;a=9.331(1) Å,b=13.698(5) Å,c=16.164(4) Å, =90.34(2)°, ß=103.03(2)°, =103.04(3)°, Z=2) shows the disilazane to be a dimer formed by linear condensation from the monomeric silazane.

     

DySBr und DySI – Synthese,Kristallstruktur und Magnetismus

DySBr and DySI – Synthesis, Crystal Structure, and Magnetism By reaction of Dy₂S₃ with Dy metal and Br₂ (I₂) at 750°C (900°C), single phase crystalline DySBr (DySI) has been synthesized. Crystal structure refinement of DySBr confirms the FeOCl-type structure (R = 0.049; space group Pmmn, Z = 2, lattice parameters (in Å): a = 5.349(2), b = 4.079(2), c = 8.066(2)) which is also ascertained for DySI (R = 0.059; lattice parameters (in Å): a = 5.320(2), b = 4.168(1), c = 9.224(5)). The magnetic susceptibilities (temperature range 3.4 K – 295 K) can be described on the basis of simple models (cubic crystal field, molecular field approximation) above 5 K and 15 K respectively. The deviations at low temperature are assumed to be related essentially to Dy—Dy exchange interactions which are not adequately described with the molecular field approach.