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Palladium(II) Sulfide
Palladium(II) sulfide is a chemical compound of palladium and sulfur with the chemical formula PdS. Like other palladium and platinum chalcogenides, palladium(II) sulfide has complex structural, electrical and magnetic properties. Preparation Palladium(II) sulfide is formed when hydrogen sulfide is passed through an aqueous solution containing palladium in the +2 oxidation state: :Pd2+ + H2S → PdS + 2H+ Berzelius reacted palladium directly with sulfur to produce palladium(II) sulfide in 1813: :Pd + S → PdS Structure The crystal structure of PdS contains approximately square planar palladium centres and tetrahedral sulfur centres. Reactivity If palladium(II) sulfide is heated with an excess of sulfur, palladium disulfide is formed: :PdS + S → PdS2 Related compounds A variety of other compounds in the Pd-S system have been reported, including Pd4S, Pd2.8S, Pd2.2S and PdS2. The mineral Braggite has the composition (Pt, Pd, Ni)S and is isomorphous with PdS. See also * ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ball-and-stick Model
In chemistry, the ball-and-stick model is a molecular model of a chemical substance which displays both the three-dimensional position of the atoms and the bonds between them. The atoms are typically represented by spheres, connected by rods which represent the bonds. Double and triple bonds are usually represented by two or three curved rods, respectively, or alternately by correctly positioned sticks for the sigma and pi bonds. In a good model, the angles between the rods should be the same as the angles between the bonds, and the distances between the centers of the spheres should be proportional to the distances between the corresponding atomic nuclei. The chemical element of each atom is often indicated by the sphere's color. In a ball-and-stick model, the radius of the spheres is usually much smaller than the rod lengths, in order to provide a clearer view of the atoms and bonds throughout the model. As a consequence, the model does not provide a clear insight about th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oxidation State
In chemistry, the oxidation state, or oxidation number, is the hypothetical charge of an atom if all of its bonds to different atoms were fully ionic. It describes the degree of oxidation (loss of electrons) of an atom in a chemical compound. Conceptually, the oxidation state may be positive, negative or zero. While fully ionic bonds are not found in nature, many bonds exhibit strong ionicity, making oxidation state a useful predictor of charge. The oxidation state of an atom does not represent the "real" formal charge on that atom, or any other actual atomic property. This is particularly true of high oxidation states, where the ionization energy required to produce a multiply positive ion is far greater than the energies available in chemical reactions. Additionally, the oxidation states of atoms in a given compound may vary depending on the choice of electronegativity scale used in their calculation. Thus, the oxidation state of an atom in a compound is purely a formalism. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Platinum Diselenide
Platinum diselenide is a transition metal dichalcogenide with the formula PtSe2. It is a layered substance that can be split into layers down to three atoms thick. PtSe2 can behave as a metalloid or as a semiconductor depending on the thickness. Synthesis Minozzi was the first to report synthesising platinum diselenide from the elements in 1909. Platinum diselenide can be formed by heating thin foils of platinum in selenium vapour at 400 °C. A platinum 111 surface exposed to selenium vapour at 270 °C forms a monolayer of PtSe2. In addition to these selenization methods, PtSe2 can be made by precipitation in water solution of Pt(IV) treated with hydrogen selenide, or by heating platinum tetrachloride with elemental selenium. Natural occurrence Platinum diselenide occurs naturally as the mineral Sudovikovite. It was named after Russian petrologist, N.G. Sudovikov who lived from 1903 to 1966. The mineral's hardness is 2 to 2. Sudovikovite was found in the Srednyaya Pa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Platinum Disulfide
Platinum disulfide is the inorganic compound with the formula Pt S2. It is a black, semiconducting solid, which is insoluble in all solvents. The compound adopts the cadmium iodide structure, being composed of sheets of octahedral Pt and pyramidal sulfide centers. Single crystals are grown by chemical vapor transport In chemistry, a chemical transport reaction describes a process for purification and crystallization of non- volatile solids. The process is also responsible for certain aspects of mineral growth from the effluent of volcanoes. The technique ... using phosphorus as the transport agent. A related compound is platinum(II) sulfide, PtS. References {{Sulfides Sulfides Sulfides,2 Transition metal dichalcogenides ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Merenskyite
Merenskyite is a rare telluride / bismuthinide mineral with the chemical formula . It is an opaque white to light gray metallic mineral that occurs as inclusions within other minerals such as chalcopyrite. It crystallizes in the trigonal crystal system. Merenskyite was first described in 1966 for an occurrence in the Merensky Reef of the Western Bushveld Igneous Complex, South Africa, and named for South African geologist Hans Merensky Hans Merensky (16 March 1871 – 21 October 1952) was a South African geologist, prospector, scientist, conservationist and philanthropist. He discovered the rich deposit of alluvial diamonds at Alexander Bay in Namaqualand, vast platinum ... (1871–1952). References {{Reflist Telluride minerals Bismuthide minerals Palladium minerals Platinum minerals Trigonal minerals Minerals in space group 164 Minerals described in 1966 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Verbeekite
Verbeekite is a rare mineral consisting of palladium diselenide PdSe2. This transition metal dichalcogenide has an unusual monoclinic structure, with pairs of selenium atoms existing as dimers forming layers between palladium atom sheets. Unit cell dimensions are: , , , , . Palladium diselenide has five polymorphs. Verbeekite can be synthesised at 11.5 GPa pressure and 1300 °C. Monolayer PdSe2 has been predicted as a semiconductor and synthesized as an electronic material. The mineral was discovered in 2002 from the Musonoi Cu-Co-Mn-U mine (Kolwezi), in the Democratic Republic of the Congo The Democratic Republic of the Congo (french: République démocratique du Congo (RDC), colloquially "La RDC" ), informally Congo-Kinshasa, DR Congo, the DRC, the DROC, or the Congo, and formerly and also colloquially Zaire, is a country in .... Verbeekite was named after geologist Théodore Verbeek who studied minerals at that mine between 1955 and 1967. References {{Reflist ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cooperite (mineral)
Cooperite is a grey mineral consisting of platinum sulfide (), generally in combinations with sulfides of other elements such as palladium and nickel (PdS and NiS). Its general formula is . It is a dimorph of braggite. It is mined as an ore of platinum and platinum group metals such as palladium. It occurs in South Africa in minable quantities and an old mine near Mount Washington on Vancouver Island. It was first described in 1928 for occurrences in the Bushveld Igneous Complex and named after South African metallurgist Richard A. Cooper who first characterized it. See also *List of minerals *List of minerals named after people This is a list of minerals named after people. The chemical composition follows name. A * Abelsonite: C31H32N4Ni – American physicist Philip Hauge Abelson (1913–2004)alfred *Abswurmbachite: Cu2+Mn3+6O8SiO4 – German mineralogist I ... References Webmineral data Platinum minerals Nickel minerals Palladium minerals Sulfide miner ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Isomorphous
In mathematics, an isomorphism is a structure-preserving mapping between two structures of the same type that can be reversed by an inverse mapping. Two mathematical structures are isomorphic if an isomorphism exists between them. The word isomorphism is derived from the Ancient Greek: ἴσος ''isos'' "equal", and μορφή ''morphe'' "form" or "shape". The interest in isomorphisms lies in the fact that two isomorphic objects have the same properties (excluding further information such as additional structure or names of objects). Thus isomorphic structures cannot be distinguished from the point of view of structure only, and may be identified. In mathematical jargon, one says that two objects are . An automorphism is an isomorphism from a structure to itself. An isomorphism between two structures is a canonical isomorphism (a canonical map that is an isomorphism) if there is only one isomorphism between the two structures (as it is the case for solutions of a univer ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Braggite
Braggite is a sulfide mineral of platinum, palladium and nickel with chemical formula: (Pt, Pd, Ni)S. It is a dense (specific gravity of 10), steel grey, opaque mineral which crystallizes in the tetragonal crystal system. It is the central member in the platinum group end-members cooperite and vysotskite. It was first described in 1932 for an occurrence in the Bushveld Igneous Complex of South Africa. Its name came from William Henry Bragg (1862–1942) and his son, William Lawrence Bragg (1890–1971). It was the first mineral that was discovered with the assistance of X rays. It occurs as magmatic segregations in layered igneous intrusions such as Bushveld, the Stillwater igneous complex, the Lac des Îles igneous complex, the island of Rùm intrusive, the Great Dyke and many others. It is one of the most common platinum group minerals. Composition The braggite composition series is between the platinum rich cooperite and palladium rich vysotskite end members in solid sol ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tetrahedral Molecular Geometry
In a tetrahedral molecular geometry, a central atom is located at the center with four substituents that are located at the corners of a tetrahedron. The bond angles are cos−1(−) = 109.4712206...° ≈ 109.5° when all four substituents are the same, as in methane () as well as its heavier analogues. Methane and other perfectly symmetrical tetrahedral molecules belong to point group Td, but most tetrahedral molecules have lower symmetry. Tetrahedral molecules can be chiral. Tetrahedral bond angle The bond angle for a symmetric tetrahedral molecule such as CH4 may be calculated using the dot product of two vectors. As shown in the diagram, the molecule can be inscribed in a cube with the tetravalent atom (e.g. carbon) at the cube centre which is the origin of coordinates, O. The four monovalent atoms (e.g. hydrogens) are at four corners of the cube (A, B, C, D) chosen so that no two atoms are at adjacent corners linked by only one cube edge. If the edge length of the cube ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Square Planar Molecular Geometry
The square planar molecular geometry in chemistry describes the stereochemistry (spatial arrangement of atoms) that is adopted by certain chemical compounds. As the name suggests, molecules of this geometry have their atoms positioned at the corners. Examples Numerous compounds adopt this geometry, examples being especially numerous for transition metal complexes. The noble gas compound XeF4 adopts this structure as predicted by VSEPR theory. The geometry is prevalent for transition metal complexes with d8 configuration, which includes Rh(I), Ir(I), Pd(II), Pt(II), and Au(III). Notable examples include the anticancer drugs cisplatin tCl2(NH3)2and carboplatin. Many homogeneous catalysts are square planar in their resting state, such as Wilkinson's catalyst and Crabtree's catalyst. Other examples include Vaska's complex and Zeise's salt. Certain ligands (such as porphyrins) stabilize this geometry. Splitting of d-orbitals A general d-orbital splitting diagram for square planar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Jöns Jacob Berzelius
Baron Jöns Jacob Berzelius (; by himself and his contemporaries named only Jacob Berzelius, 20 August 1779 – 7 August 1848) was a Swedish chemist. Berzelius is considered, along with Robert Boyle, John Dalton, and Antoine Lavoisier, to be one of the founders of modern chemistry. Berzelius became a member of the Royal Swedish Academy of Sciences in 1808 and served from 1818 as its principal functionary. He is known in Sweden as the "Father of Swedish Chemistry". Berzelius Day is celebrated on 20 August in honour of him. Although Berzelius began his career as a physician, his enduring contributions were in the fields of electrochemistry, chemical bonding and stoichiometry. In particular, he is noted for his determination of atomic weights and his experiments that led to a more complete understanding of the principles of stoichiometry, which is the branch of chemistry pertaining to the quantitative relationships between elements in chemical compounds and chemical reactions and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
