SEARCH · Engineering Papers
Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.
Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.
WCl6(S)8 is Magnesium tetraboride-like structured and crystallizes in the triclinic P-1 space group. The structure is zero-dimensional and consists of two octasulfur molecules and two tungsten(vi) chloride molecules.
WCl6((CH3)2NH2)2C4N2H16Cl is Silicon tetrafluoride-derived structured and crystallizes in the orthorhombic P2_12_12 space group. The structure is zero-dimensional and consists of four dimethylazanium molecules, two tungsten(vi) chloride molecules, and two C4N2H16Cl clusters. In each C4N2H16Cl cluster, there are two inequivalent C2- sites. In the first C2- site, C2- is bonded to one N3- and three H1+ atoms to form corner-sharing CH3N tetrahedra. The C–N bond length is 1.49 Å. There is two shorter (1.09 Å) and one longer (1.10 Å) C–H bond length. In the second C2- site, C2- is bonded to one N3- and three H1+ atoms to form corner-sharing CH3N tetrahedra. The C–N bond length is 1.49 Å. All C–H bond lengths are 1.10 Å. N3- is bonded in a tetrahedral geometry to two C2- and two H1+ atoms. There is one shorter (1.04 Å) and one longer (1.06 Å) N–H bond length. There are eight inequivalent H1+ sites. In the first H1+ site, H1+ is bonded in a single-bond geometry to one C2- atom. In the second H1+ site, H1+ is bonded in a single-bond geometry to one C2- atom. In the third H1+ site, H1+ is bonded in a single-bond geometry to one C2- atom. In the fourth H1+ site, H1+ is bonded in a single-bond geometry to one N3- and one Cl1- atom. The H–Cl bond length is 2.02 Å. In the fifth H1+ site, H1+ is bonded in a single-bond geometry to one C2- atom. In the sixth H1+ site, H1+ is bonded in a single-bond geometry to one C2- atom. In the seventh H1+ site, H1+ is bonded in a single-bond geometry to one C2- atom. In the eighth H1+ site, H1+ is bonded in a single-bond geometry to one N3- atom. Cl1- is bonded in a bent 150 degrees geometry to two equivalent H1+ atoms.
WCl6(Se)4Se2I crystallizes in the triclinic P-1 space group. The structure is zero-dimensional and consists of four selenium molecules, one tungsten(vi) chloride molecule, and one Se2I cluster. In the Se2I cluster, Se+0.33+ is bonded in a single-bond geometry to one I1- atom. The Se–I bond length is 2.79 Å. I1- is bonded in a linear geometry to two equivalent Se+0.33+ atoms.
WCl6(Te)2 crystallizes in the triclinic P-1 space group. The structure is zero-dimensional and consists of four tellurium molecules and two tungsten(vi) chloride molecules.
WCl6(Te)2 crystallizes in the monoclinic P2_1/c space group. The structure is zero-dimensional and consists of eight tellurium molecules and four tungsten(vi) chloride molecules.
WCl4 crystallizes in the monoclinic C2/m space group. The structure is one-dimensional and consists of two WCl4 ribbons oriented in the (0, 1, 0) direction. W4+ is bonded to six Cl1- atoms to form edge-sharing WCl6 octahedra. There are a spread of W–Cl bond distances ranging from 2.31–2.53 Å. There are three inequivalent Cl1- sites. In the first Cl1- site, Cl1- is bonded in a water-like geometry to two equivalent W4+ atoms. In the second Cl1- site, Cl1- is bonded in a 2-coordinate geometry to two equivalent W4+ atoms. In the third Cl1- site, Cl1- is bonded in a single-bond geometry to one W4+ atom.
(WCl6)2N2 crystallizes in the monoclinic C2/c space group. The structure is zero-dimensional and consists of four ammonia molecules and four tungsten(vi) chloride molecules.
Tungsten is a refractory metal with a very high melting point (3422 °C), hardness (7.5 on Mohs hardness scale), and chemical resistance, making it useful in applications with extreme conditions. Electrodeposition is an attractive technique for coating metals because of its scalability and applicability to objects of intricate shape, though tungsten electrodeposition remains difficult. Some multi-step methods first coat either a sacrificial metal such as zinc or a layer of tungsten oxide which is then converted to metallic tungsten with WCl6 immersion (i.e. a redox replacement reaction) or heating in a reducing atmosphere, respectively. Single step deposition would save time and money, making it more viable on an industrial scale. Most reports detailing direct tungsten electrodeposition use molten salts which are energy intensive, hazardous, and difficult to maintain. Few reports have demonstrated single-step, low temperature electrodeposition deposition of tungsten in atmosphere. An article from 1931 reports successful metal tungsten electrodeposition from a highly basic sodium tungstate solution, though the authors reported very low current efficiency (<1%) and required heating to 80+ °C to obtain metallic films. This report outlines our attempts to electroplate tungsten from various solutions on different electrode materials, none of which succeeded. Our intent is to guide future researchers at Los Alamos National Laboratory that would attempt tungsten electrodeposition.