Ferrocenyl aryl ethers can be synthesized in good yields by Cu(I)/phosphine-catalyzed coupling reactions from iodoferrocene or 1,1'-dibromoferrocene and various phenols in toluene, using Cs2CO3 or K3PO4 as a base. For the first time a solid-state structure of a ferrocenyl-1,1'-diaryl ether [1,1'-di(4-tert-butylphenoxy)ferrocene] has been determined from single-crystal X-ray data. The mixed ferrocenyl aryl ether 1-(4-tert-butylphenoxy)-1'-(2,4-dimethylphenoxy)ferrocene was prepared in a two-step synthetic protocol.

AbstractDifferential scanning calorimetry indicates a structural phase transition of high‐purity single crystal β‐rhombohedral boron close to 550 K.

Differential scanning calorimetry (DSC) of high-purity, single crystal beta-rhombohedral boron (melting point 2365 K) evidences a structural phase transition close to 550 K, which is obviously responsible for discontinuities of numerous physical properties in this temperature region. These can be consistently interpreted assuming site hopping of boron atoms between regular, partially occupied crystallographic sites in the crystal structure. This site hopping is influenced by optical excitation. (c) 2012 Elsevier Masson SAS. All rights reserved.

(Triptycenedicarboxylato)zinc metal-organic frameworks (MOFs) based on paddle wheel secondary building units (SBUs) with different axial ligands have been prepared. The reproducible formation of the layered paddle-wheel structures from triptycenedicarboxylic acid (H2TDC) and zinc nitrate under various conditions seems to be characteristic of this acid and is utilized for the construction of 3D frameworks by a pillaring approach. We attempted to bring additional functionalities into MOFs by employing the appropriate pillaring ligands, for example, bis(4-pyridyl)-s-tetrazine and bis(4-pyridyl)-dimethoxy-p-phenylenedivinylene, and investigated certain properties of some MOF materials, such as guest-exchange behavior, luminescence, microporosity, and stability.

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

trans-[PdBr2(NHC)Im] was prepared by reacting the corresponding imidazolium (Im) salt with palladium(II) acetate in dimethylsulfoxide in an in-situ reaction without generating a free carbene. Both the salt and the complex were characterized spectroscopically and by X-ray structure analysis. The complex was tested in homogeneous Suzuki–Miyaura cross-coupling reactions.

The reaction of Ni(COD)(2) with a ligand containing a biphenyl subunit (P(Pr-i)(2)-O-Ph-Ph-O-P(Pr-i)(2), L1) resulted in a mixture of compounds, the main product being, [L1]Ni(COD), which could be quantitatively transferred to product 2 using bis(p-toluyl)acetylene. The possible activation products, cis-and trans-3 (3(c) and 3(t), respectively), which would result from the cleavage of the bridging C-C single bond were synthesized independently. The mechanism of the cis/trans-isomerization was examined, activation parameters determined and trapping tests performed. Reaction of (PPh3)(2)Ni(CO)(2) with L1 gave a novel complex 4 by a ligand exchange reaction. This Compound, when heated to 95 degrees C under a 5 bar atmosphere of CO for several days, slowly incorporated CO into the bridging C-C single bond. This behavior as well as isotopic labeling experiments with (CO)-C-13 indicated that, following a dissociation of CO in complex 4, an interaction between the metal center and the biphenyl moiety is induced, leading to activation. The reaction of Ni(COD)(2) with P(Pr-i)(2)-O-Ph-CO-Ph-O-(P(Pr-i)(2) (L3), which contains a benzophenone moiety, resulted in the quantitative activation of the PhC-CO bond at 20 degrees C, leading to complexes 3(c/t) (trans/cis 80/20 at 20 degrees C). The mechanism was examined and intermediates of it were identified as well as activation parameters for their further reaction determined. Reaction of (PPh3)(2)Ni(CO)(2) with L3 gave complex 5, which is stable at 20 degrees C. Complexes 3(c/t) were shown to react quantitatively to give compound 5 under an atmosphere of CO. Selective isotopic labeling with (CO)-C-13 proved that an activation similar to that observed with Ni(COD)(2) occurs in complex. 5 at 95 degrees C but much more slowly and is accompanied by the formation of complex 4. Molecular structures of the novel complexes 2, 3(c), 4, and 5 have been determined by single crystal X-ray diffraction studies.

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

The reactions of the Zintl phase K2Cs2Sn9 with elemental tellurium and selenium in ethylenediamine have been investigated. From the reaction of K2CS2Sn9 with elemental tellurium [K-(2,2,2-cryPt)](4)Te6Te4 (2) and [K-(2,2,2-crypt)](2)Sn2Te3 (3) were obtained, whereas the reaction of K2Cs2Sn9 with elemental selenium led to the formation of [K-(2,2,2-crypt)](2)Sn(Se-4)(3) (4) and [K-(2,2,2-crypt)](2)Cs2Sn2Se6 center dot 2en (5)(1)). Compounds 2, 4, 5 have been characterized by single crystal X-ray structure determination.

Rhodium(I) complexes of acceptor substituted N-heterocyclic carbenes were obtained either by transmetalation from the corresponding Ag(I) complexes or by thermal decomposition of corresponding pentafluorobenzene carbene adducts. All complexes were fully characterized by means of NMR- and mass spectroscopy. Compounds 5, 6, 7 and 11 were although characterized by single-crystal X-ray analysis. The relative sigma-donor/pi-acceptor strength of the NHC ligands was determined by means of IR spectroscopy. Dimerisation behaviour of Rh carbonyl complexes was studied. (C) 2008 Elsevier B.V. All rights reserved.

Condensation of anilines and primary aliphatic amines with 3,4-diphenylcyclo-2-pentenone leads to the corresponding diphenylcyclopentene imines in good yields of 72-90%. Deprotonation of these aminocyclopentadiene tautomers and reaction with FeCl2 leads to the synthesis of the respective 1,1'-diamino-3,3',4,4'-tetraphenylferrocenes. Yields increase from 33% to 65% with a decrease in the steric bulk of the amine substituent. The observation that a successful conversion requires two equivalents of base is conceived on the basis of the discussed reaction mechanism. The molecular structure of 1,1'-dianilino-3,30,4,40-tetraphenylferrocene ( 3a), which was determined by single crystal X-ray analysis reveals a trans coordination of the two amine moieties with respect to the central Cp-Fe-Cp axis of the ferrocenyl backbone. (C) 2007 Elsevier B. V. All rights reserved.

A chiral C-2-symmetric diamine was prepared from (S)-3-phenyl-3,4-dihydroisoquinoline by the virtue of asymmetric transformation. Rhodium and iridium complexes of chiral N-heterocyclic carbenes with restricted flexibility derived from 3,3'-substituted partially reduced biisoquinoline were obtained by transmetalation from the corresponding silver(I) complexes. Unexpected double-bond formation in the carbene ligand has occurred during a transmetalation step. The structures of these complexes were verified by X-ray diffraction. Metal complexes of these N-heterocyclic carbenes were applied to the asymmetric hydrogenation of methyl 2-acetamidoacrylate. Good enantioselectivities of up to 67% ee were achieved.

The title compound [K([2.2]crypt](2)[HgGe9](dmf)(1)) (1) has been obtained by reaction of elemental mercury with the binary phase of the formal composition K4Ge9 in dmf and after addition of [2.2]crypt. The X-ray single crystal analysis shows that 1 contains polymeric (1)(infinity)[HgGe9](2-) units in which Geg clusters are linked together by mercury atoms. The differences in the structures of 1 and the related compound [K([2.2.2]Crypt)](2)[HgGe9](en)(2)(2)) 2 are discussed.

Several mixed palladium(II) complexes bearing 2,3-diarylcyclopropenylidene ligands (aryl = phenyl, mesityl, naphthyl) and triaryland. trialkylphosphines have been prepared. Single crystal structure details of one of the dimeric chloro-bridged complexes as well as of two monomeric phosphine substituted complexes are presented and compared with appropriate structural features of similar 2,3-diaminocyclopropenylidene- and cycloheptatrienylidene complexes. The new complexes were tested as catalysts in Suzuki-Mijaura coupling reactions with bromo- and chloroarenes and their catalytic activity compared with that of analogous NHC- and cycloheptatrienylidene complexes. (c) 2007 Elsevier B.V. All rights reserved.

The preparation of unsaturated NHC-substituted phosphitepalladacycles via phosphitepalladacycle acetato and chloro precursors and azoliurn salts with non-coordinating anions in DMSO is reported. With this one-pot synthesis NHC-substituted phosphitepalladacycles are obtained avoiding multi-step reactions. The molecular structures of an acetate-bridged phosphitepalladacycle dimer, an unsaturated NHC-substituted palladacyclic complex and one acetylacetonato phosphapalladacycle complex have been determined by single-crystal X-ray analysis. (c) 2007 Elsevier B.V. All rights reserved.

The clathrate compound alpha-Cs8Sn44 square(2) has been synthesized from its elements under inert gas conditions and has been characterized by single-crystal and powder X-ray diffraction. At room temperature, it crystallizes with cubic symmetry [a = 24.256(3) angstrom, space group Ia (3) over bard, Z = 81 and adopts a 2 x 2 x 2 superstructure of the type-I clathrate and a high ordering of the vacancies (square) in the Sn framework. Single crystals of alpha-Cs8Sn44 square(2) reversibly transform at 90 degrees C to the high-temperature P form with primitive symmetry [alpha = 12.135(1) angstrom, space group Pm (3) over barn, Z = 1] and a lower ordering of the defects. Differential thermal analysis corroborates the reversible character of the phase transition, which occurs with an enthalpy change of approximately 0.38 J g(-1). An atom-migration mechanism describing the order-disorder transition involving spiro-connected six-membered rings only (scsr mechanism) is proposed. ((C) Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)

Gold verbindet: Der erste lösliche Au-Ge-Cluster wurde bei der Reaktion von [Au(PPh3)Cl] mit K4Ge9 erhalten. Das Produkt [Ge9Au3Ge9]5− (siehe Bild) hat bemerkenswerte Eigenschaften: In Gegenwart polyanionischer Zintl-Ionen beobachtet man linear koordinierte Goldatome sowie die Merkmale aurophiler Kontakte zwischen den Metallatomen.

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.