Ultrafiie WC powders were produced from WCla-C3Hs-H2 gas mixtures in a conventional tubular hot-wall downstream CVD reactor. At reaction temperatures between 1100 and 1550°C powders containing W, WZC, WC and carbon were produced. The overall chemical compositions of the tungsten coinpounds as well as the free carbon contents depended strongly on the reaction temperature and the ratio of the rea...

Chlorine ligands in a variety of diamagnetic transition-metal (TM) complexes in common structural motifs were studied using (35)Cl solid-state NMR (SSNMR), and insight into the origin of the observed (35)Cl NMR parameters was gained through first-principles density functional theory (DFT) calculations. The WURST-CPMG pulse sequence and the variable-offset cumulative spectrum (VOCS) methods were...

It is generally believed that cyano functionality is “toxic” to the classical MoCl5and WCl6based metathesis catalysts, but we here present such an example in which a group of cyano-containing acetylene monomers are polymerized by the “simple” metal halides. The WCl6(-Ph4Sn) catalysts in dioxane initiate the polymerizations of n-{[(4′-cyano-4-biphenylyl)oxy]carbonyl}-1-alkynes (AnCN; n ) 2, 3, 8...

Dehydration of glucose to 5-hydroxymethylfurfural (HMF) remains a significant problem in the context of the valorization of lignocellulosic biomass. Hydrolysis of WCl6 and NbCl5 leads to precipitation of Nb-containing tungstite (WO3 ⋅H2 O) at low Nb content and mixtures of tungstite and niobic acid at higher Nb content. Tungstite is a promising catalyst for the dehydration of glucose to HMF. Co...

Simultaneous reduction of WCl6 and CCl4 with bismuth metal at 400 degrees C affords a black solid, from which the new cluster [W6CCl18]2- is extracted into aqueous HCl. The cluster is isolated in 34% yield as (Bu4N)2[W6CCl18] and features a metal-metal bonded W6 trigonal prism centered by a carbon atom and surrounded by 12 edge-bridging and 6 terminal chloride ligands. A cyclic voltammogram of ...

Biphenyl(Biph-) containing 1-alkynes (3 and 4) and their polymers (1 and 2) with varying bridge groups and spacer lengths were synthesized and the effects of the structural variation on their properties, especially their mesomorphism and photoluminescence behaviors, were studied. The acetylene monomers 3(3) [HCtC(CH2)3O-Biph-OCO(CH2)10CH3] and 4(m) [HCtC(CH2)mOCO-Biph-OCO(CH2)10CH3, m ) 3, 4] w...

Group 3-15 metal chlorides (Lewis acids) were classified on the basis of activity and aldehyde- and aldimine-selectivity in an addition reaction of a silyl enol ether. Based on the experimental results, metal chlorides (Lewis acids) were classified as follows: A, active; B, weak; C, inactive for the activation of the aldehyde and/or aldimines. Groups A and B were further divided into A-1 or B-1...