2,512 research outputs found
1-(4-Bromo-3-chloroÂphenÂyl)-3-methÂoxy-3-methylÂurea (chlorbromuron)
In the title urea-based herbicide, C9H10BrClN2O2, there exist multiple inter- and intraÂmolecular interÂactions. Most notably, the intraÂmolecular hydrogen bond between the urea carbonyl O atom and an aromatic H atom affects the planarity and torsion angles of the molÂecule by restricting rotations about the Ar—secondary amine N and the secondary amine N and the carbonyl C. The two N atoms in the urea fragment are in different environments. One is planar; the other, pseudo-C
3v. It is likely that the different nitroÂgen-atom geometries and the restricted rotations within the molÂecule impact the bioactivity of chlorbromuron
2-Methyl-4,4-dioxo-N-phenyl-5,6-diÂhydro-1,4-oxathiine-3-carboxamide (Oxycarboxin)
In the title compound, C12H13NO4S, a systemic fungicide, the heterocycle adopts a lounge chair conformation and the dihedral angle between the ring planes is 25.8 (2)°. InterÂmolecular C—H⋯O hydrogen bonds are noted in the crystal structure. Also observed is a short interÂaction of a methylÂene hydrogen atom with the Ï€-electron system of a phenyl ring in an adjacent molÂecule
Structures performance, benefit, cost-study
New technology concepts and structural analysis development needs which could lead to improved life cycle cost for future high-bypass turbofans were studied. The NASA-GE energy efficient engine technology is used as a base to assess the concept benefits. Recommended programs are identified for attaining these generic structural and other beneficial technologies
Electrochemic properties of single-wall carbon nanotube electrodes
The electrochemical properties of single-wall carbon nanotube ~CNT! electrodes in the form of sheets or papers have been examined. Thermal annealing has produced significant changes in a range of properties of the material including increased hydrophobicity and elimination of electroactive surface functional groups and other impurities. As a result of these changes, the treated electrodes exhibit lower double-layer capacitance, absence of faradaic responses and associated pseudocapacitance, and a better frequency response. The basic electrochemical behavior of the CNT paper electrodes is not markedly affected by relatively large differences in electrolyte ion size, consistent with an average pore size of 9 nm. Increases in both CNT sheet thickness and surface area induce a slower electrode response in agreement with the porous nature of the electrode matrix
Chlorido(η4-1,5-cycloÂoctaÂdiene)[(pentaÂfluoroÂethÂyl)diphenylÂphosphane]iridium(I)
The title structure,[IrCl(C8H12)(C14H10F5P)], reveals that (C2F5)PPh2 (pentaÂfluoroÂethylÂdiphenylÂphosphane or pfepp) disrupts the iridium dimer [(cod)IrCl]2 (cod = cycloÂocta-1,5-diene) by rupturing the bridging chloride ligands and binding in the open coordination site to form (cod)Ir(pfepp)Cl with the IrI atom in a distorted square-planar coordination environment. The structure deviates very little from the IrI–triphenylÂphosphine analog, although a significantly (∼20σ) shorter Ir—P bond is noted for the title compound
1,1′-Diketone and 1,1′-dinitrile Derivatives of 2,2′-biimidazole
The crystal structures of 2,2′-biimidazole-1,1′-diacetone, C12H14N4O2, and 2,2′-biimidazole-1,1′-diacetonitrile, C10H8N6, have been determined. Both molecules crystallize with coplanar rings having substituents in a trans disposition with a center of inversion located midway between the bridging C atoms
2,4-Dinitrophenylhydrazones of 2,4-dihydroxybenzaldehyde, 2,4-dihydroxyacetophenone and 2,4-dihydroxybenzophenone
In 2,4-dihydroxybenzaldehyde 2,4-dinitrophenylhydrazone N,N-dimethylformamide solvate (or 4-[(2,4-dinitrophenyl)-hydrazonomethyl]benzene-1,3-diol N,N-dimethylformamide solvat
Carbon nanotube electroactive polymer materials: opportunities and challenges
Carbon nanotubes (CNTs) with macroscopically ordered structures (e.g., aligned or patterned mats, fibers, and sheets) and associated large surface areas have proven promising as new CNT electroactive polymer materials (CNT-EAPs) for the development of advanced chemical and biological sensors. The functionalization of CNTs with many biological species to gain specific surface characteristics and to facilitate electron transfer to and from them for chemical- and bio-sensing applications is an area of intense research activity. Mechanical actuation generated by CNT-EAPs is another exciting electroactive function provided by these versatile materials. Controlled mechanical deformation for actuation has been demonstrated in CNT mats, fibers, sheets, and individual nanotubes. This article summarizes the current status and technological challenges for the development of electrochemical sensors and electromechanical actuators based on carbon nanotube electroactive materials
N,N,N′,N′-TetraÂmethylÂethyleneÂdiammonium tetraÂchloridocobaltate(II)
The asymmetric unit of the title compound, [(CH3)2NH(CH2)2NH(CH3)2][CoCl4], contains a tetraÂchloridoÂcobaltÂate(II) dianion and two halves of two centrosymmetric, crystallographically-independent, dications. One independent dication is disordered between two conformations in a 0.784 (13):0.216 (13) ratio. In the crystal, interÂmolecular N—H⋯Cl hydrogen bonds link cations and anions into chains propagated in [01]. These hydrogen bonds contribute to the distorted tetraÂhedral geometry at the CoII atom
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