1-(5-Chloro-2,4-dihydroxy­phen­yl)-2-(4-ethoxy­phen­yl)ethanone

The structure of the title compound, C16H15ClO4, contains aryl rings which are inclined by 75.6 (1)° to each other. It displays intra­molecular O—H⋯O hydrogen bonding between the 2-hydr­oxy and carbonyl groups, forming a six-membered ring. Furthermore, the 4-hydr­oxy group, acting as a hydrogen-bond donor, is bound to the O atom of the 2-hydr­oxy group of another mol­ecule

Improved one-dimensional models for rapid emptying and filling of pipelines

Improved one-dimensional (1D) models-compared to previous work by the authors-are proposed which are able to predict the velocity, length, and position of the liquid column in the rapid emptying and filling of a pipeline. The models include driving pressure and gravity, skin friction and local drag, and holdup at the tail and gas intrusion at the front of the liquid column. Analytical and numerical results are validated against each other, and against experimental data from a large-scale laboratory setup

Epitaxial Electrodeposition of Chiral Metal Surfaces on Silicon(643)

Surfaces of achiral materials exhibit two-dimensional chirality if they lack mirror symmetry. An example is the (643) surface of face-centered-cubic metals such as Au. The (643) and (643) surfaces are non-superimposable mirror images of each other. Chiral surfaces offer the possibility of serving as heterogeneous catalysts for chiral synthesis or providing a platform for chiral separation or crystallization. Here, we show the symmetry requirements for surface chirality, and we demonstrate that chiral surfaces can be produced by electrochemically depositing epitaxial films of Au onto commercially available Si(643) wafers. Au(643) is deposited onto one side of the wafer, and its enantiomer Au(643) is deposited on the other side of the wafer. In addition to the (643) orientation, the (8 14 17) orientation of Au is produced on the Si(643) wafers. The (8 14 17) orientation has a similar kinked surface to the (643) surface, but it has staggered kinks. Other metal films including Pt, Ni, Cu, and Ag that are electrodeposited onto the Au films exhibit strong in-plane and out-of-plane order. Hence, the method provides a pathway for producing chiral surfaces of a wide range of materials, and it obviates the need to work with expensive single crystals. The Ag/Au/Si(643) surface showed a preference for the electrochemical oxidation of d-glucose, whereas the Ag/Au/Si(643) surface showed preference for the oxidation of l-glucose

New bisphosphinites from pamoic acid

Reaction of PhPCl2 with pamoic acid in a 2:1 molar ratio gives a bisphosphinite 5 as a conformational mixture of 5a and 5b which show different solubility in THF and Et2O. The less soluble biaxial conformer 5a was isolated spectrally pure, while it is very difficult to get pure biequatorial 5b without contamination of 5a. Oxidation of 5a with hydrogen peroxide/elemental sulfur or selenium gave the corresponding chalcogenides. The conformational features of the compounds were revealed by X-ray crystallography. In addition, two examples of complexes of 5a were prepared, the chelate complex [PtCl2{(5a)-P, P'}] and the bis-rhodium bridging complex from [RhCl2Cp*](2) dimer.</p

New bisphosphinites from pamoic acid

Reaction of PhPCl2 with pamoic acid in a 2:1 molar ratio gives a bisphosphinite 5 as a conformational mixture of 5a and 5b which show different solubility in THF and Et2O. The less soluble biaxial conformer 5a was isolated spectrally pure, while it is very difficult to get pure biequatorial 5b without contamination of 5a. Oxidation of 5a with hydrogen peroxide/elemental sulfur or selenium gave the corresponding chalcogenides. The conformational features of the compounds were revealed by X-ray crystallography. In addition, two examples of complexes of 5a were prepared, the chelate complex [PtCl2{(5a)-P, P'}] and the bis-rhodium bridging complex from [RhCl2Cp*](2) dimer.</p

Improvement of the Fe-NTA sulfur recovery system by the addition of a hydroxyl radical scavenger

The degradation of Nitrilotriacetic Acid (NTA), which results from the oxidation of hydroxyl radicals formed in the process, is a major deficiency in the present Fe-NTA system for the oxidation of hydrogen sulfide to sulfur by air. The degradation of NTA can be slowed down considerably by the addition of a hydroxyl radical scavenger. In this study, a series of inorganic and organic materials was tested as scavengers/inhibitors of hydroxyl radicals in attempts to improve the Fe-NTA system. The results showed that N-methylpyrrolidinone and ethylene glycol could be used as potentially powerful scavengers of hydroxyl radicals to improve the Fe-NTA system.</p

An improved 1D model for liquid slugs travelling in pipelines An improved 1D model for liquid slugs travelling in pipelines CASA-14-16 AN IMPROVED 1D MODEL FOR LIQUID SLUGS TRAVELLING IN PIPELINES

ABSTRACT An improved one-dimensional (1D) model compared to previous work by the authors is proposed which is able to predict the acceleration and shortening of a single liquid slug propagating in a straight pipe with a downstream bend. The model includes holdup at the slug&apos;s tail and flow separation at the bend. The obtained analytical and numerical results are validated against experimental data. The effects of the improvement and of holdup are examined in a parameter variation study

Novel heterocyclic selenazadiphospholaminediselenides, zwitterionic carbamidoyl(phenyl)-phosphinodiselenoic acids and selenoureas derived from cyanamides

2,4-Bis(phenyl)-1,3-diselenadiphosphetane-2,4-diselenide (Woollins' reagent, WR) reacts with cyanamides (1a-h) in refluxing toluene to afford a series of novel selenazadiphospholaminediselenides (RR'NC=N(PhP(Se)SeP(Se)Ph, R=C6H5(CH2)(1-3), 4-n-C10H21C6H4 and 4-BrC6H4CH2; R'=H, CH3, C2H5 and C(O)OC2H5 2a-g). Post-treatment of the reaction mixture with water led to the formation of carbamidoyl(phenyl)phosphinodiselenoic acids (RR'NC(NH2)P(SeH)(2)Ph, R=C6H5(CH2)(2-3), 4-n-C10H21C6H4 and 4-BrC6H4CH2; R'=H and CH3, 3b, 3c, 3e and 3f) and selenoureas (RR'NC(Se)NH2, R=C6H5(CH)(1-2); R'=CH3 and OC(O)C2H5, 4f and 4h) in moderate to excellent yields. All new compounds are characterised spectroscopically and five X-ray crystal structures are reported. (C) 2009 Elsevier Ltd. All rights reserved.</p