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Platinum(II) Bis(acetylacetonate)
Platinum(II) bis(acetylacetonate) is the coordination compound with the formula Pt(O2C5H7)2, abbreviated Pt(acac)2. The homoleptic acetylacetonate complex of platinum(II), it is a yellow, benzene-soluble solid. According to X-ray crystallography, the Pt center is square planar. The compound is a widely used precursor to platinum-based catalysts. The complex is prepared by the reaction of the platinum(II) aquo complex t(H2O)4sup>2+ with acetylacetone. See also * Palladium(II) bis(acetylacetonate) * Nickel(II) bis(acetylacetonate) Nickel(II) bis(acetylacetonate) is a coordination complex with the formula i(acac)2, where acac is the Ion, anion derived from deprotonation of acetylacetone. It is a dark green Paramagnetism, paramagnetic solid that is soluble in organic sol ... References {{Acetylacetonate complexes Acetylacetonate complexes Platinum complexes ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Coordination Compound
A coordination complex is a chemical compound consisting of a central atom or ion, which is usually metallic and is called the ''coordination centre'', and a surrounding array of chemical bond, bound molecules or ions, that are in turn known as ''ligands'' or complexing agents. Many metal-containing chemical compound, compounds, especially those that include transition metals (elements like titanium that belong to the periodic table's d-block), are coordination complexes. Nomenclature and terminology Coordination complexes are so pervasive that their structures and reactions are described in many ways, sometimes confusingly. The atom within a ligand that is bonded to the central metal atom or ion is called the donor atom. In a typical complex, a metal ion is bonded to several donor atoms, which can be the same or different. A Ligand#Polydentate and polyhapto ligand motifs and nomenclature, polydentate (multiple bonded) ligand is a molecule or ion that bonds to the central atom ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Acetylacetonate Complex
Metal acetylacetonates are coordination complexes derived from the acetylacetonate anion () and metal ions, usually transition metals. The bidentate ligand acetylacetonate is often abbreviated acac. Typically both oxygen atoms bind to the metal to form a six-membered chelate ring. The simplest complexes have the formula M(acac)3 and M(acac)2. Mixed-ligand complexes, e.g. VO(acac)2, are also numerous. Variations of acetylacetonate have also been developed with myriad substituents in place of methyl (RCOCHCO−). Many such complexes are soluble in organic solvents, in contrast to the related metal halides. Because of these properties, acac complexes are sometimes used as catalyst precursors and reagents. Applications include their use as NMR "shift reagents" and as catalysts for organic synthesis, and precursors to industrial hydroformylation catalysts. in some cases also binds to metals through the central carbon atom; this bonding mode is more common for the third-row transition me ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
X-ray Crystallography
X-ray crystallography is the experimental science of determining the atomic and molecular structure of a crystal, in which the crystalline structure causes a beam of incident X-rays to Diffraction, diffract in specific directions. By measuring the angles and intensities of the X-ray diffraction, a crystallography, crystallographer can produce a three-dimensional picture of the density of electrons within the crystal and the positions of the atoms, as well as their chemical bonds, crystallographic disorder, and other information. X-ray crystallography has been fundamental in the development of many scientific fields. In its first decades of use, this method determined the size of atoms, the lengths and types of chemical bonds, and the atomic-scale differences between various materials, especially minerals and alloys. The method has also revealed the structure and function of many biological molecules, including vitamins, drugs, proteins and nucleic acids such as DNA. X-ray crystall ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Square Planar
In chemistry, the square planar molecular geometry 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 xenon tetrafluoride 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)2 and 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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Catalyst
Catalysis () is the increase in rate of a chemical reaction due to an added substance known as a catalyst (). Catalysts are not consumed by the reaction and remain unchanged after it. If the reaction is rapid and the catalyst recycles quickly, very small amounts of catalyst often suffice; mixing, surface area, and temperature are important factors in reaction rate. Catalysts generally react with one or more reactants to form intermediates that subsequently give the final reaction product, in the process of regenerating the catalyst. The rate increase occurs because the catalyst allows the reaction to occur by an alternative mechanism which may be much faster than the noncatalyzed mechanism. However the noncatalyzed mechanism does remain possible, so that the total rate (catalyzed plus noncatalyzed) can only increase in the presence of the catalyst and never decrease. Catalysis may be classified as either homogeneous, whose components are dispersed in the same phase (usual ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aquo Complex
In chemistry, metal aquo complexes are coordination compounds containing metal ions with only water as a ligand. These complexes are the predominant species in aqueous solutions of many metal salts, such as metal nitrates, sulfates, and perchlorates. They have the general stoichiometry . Their behavior underpins many aspects of environmental, biological, and industrial chemistry. This article focuses on complexes where water is the only ligand (" homoleptic aquo complexes"), but of course many complexes are known to consist of a mix of aquo and other ligands. Stoichiometry and structure Hexa-aquo complexes Most aquo complexes are mono-nuclear, with the general formula , with or 3; they have an octahedral structure. The water molecules function as Lewis bases, donating a pair of electrons to the metal ion and forming a dative covalent bond with it. Typical examples are listed in the following table. Tutton's salts are crystalline compounds with the generic formula (where ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Acetylacetone
Acetylacetone is an organic compound with the chemical formula . It is classified as a 1,3-diketone. It exists in equilibrium with a tautomer . The mixture is a colorless liquid. These tautomers interconvert so rapidly under most conditions that they are treated as a single compound in most applications. Acetylacetone is a building block for the synthesis of many coordination complexes as well as heterocyclic compounds. Properties Tautomerism The Keto–enol tautomerism, keto and enol tautomers of acetylacetone coexist in solution. The enol form has C2v molecular symmetry, symmetry, meaning the hydrogen atom is shared equally between the two oxygen atoms. In the gas phase, the equilibrium constant, ''K''keto→enol, is 11.7, favoring the enol form. The two tautomeric forms can be distinguished by NMR spectroscopy, IR spectroscopy and other methods. The equilibrium constant tends to be high in nonpolar solvents; when ''K''keto→enol is equal or greater than 1, the enol form ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Palladium(II) Bis(acetylacetonate)
Palladium(II) bis(acetylacetonate) is a compound with formula Pd(C5H7O2)2. This yellow solid is the most common palladium complex of acetylacetonate. This compound is commercially available and used as a catalyst precursor in organic synthesis. The molecule is relatively planar with idealized D2h symmetry. See also * Platinum(II) bis(acetylacetonate) * Nickel(II) bis(acetylacetonate) Nickel(II) bis(acetylacetonate) is a coordination complex with the formula i(acac)2, where acac is the Ion, anion derived from deprotonation of acetylacetone. It is a dark green Paramagnetism, paramagnetic solid that is soluble in organic sol ... References Palladium compounds Acetylacetonate complexes Catalysts {{organic-compound-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nickel(II) Bis(acetylacetonate)
Nickel(II) bis(acetylacetonate) is a coordination complex with the formula [Ni(acac)2]3, where acac is the Ion, anion derived from deprotonation of acetylacetone. It is a dark green Paramagnetism, paramagnetic solid that is soluble in organic solvents such as toluene. It reacts with water to give the blue-green Metal aquo complex, diaquo complex Ni(acac)2(H2O)2. Structure and properties Anhydrous nickel(II) acetylacetonate exists as molecules of Ni3(acac)6. The three nickel atoms are approximately collinear and each pair of them is Bridging ligand, bridged by two μ2 oxygen atoms. Each nickel atom has Octahedral molecular geometry#Jahn–Teller effect, tetragonally distorted octahedral geometry, caused by the difference in the length of the Ni–O bonds between the bridging and non-bridging oxygens. Ni3(acac)6 molecules are almost Molecular symmetry, centrosymmetric, despite the non-centrosymmetric point group of the ''cis''-Ni(acac)2 "monomers," which is uncommon. The Trimer (che ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Acetylacetonate Complexes
Acetylacetone is an organic compound with the chemical formula . It is classified as a 1,3-diketone. It exists in equilibrium with a tautomer . The mixture is a colorless liquid. These tautomers interconvert so rapidly under most conditions that they are treated as a single compound in most applications. Acetylacetone is a building block for the synthesis of many coordination complexes as well as heterocyclic compounds. Properties Tautomerism The keto and enol tautomers of acetylacetone coexist in solution. The enol form has C2v symmetry, meaning the hydrogen atom is shared equally between the two oxygen atoms. In the gas phase, the equilibrium constant, ''K''keto→enol, is 11.7, favoring the enol form. The two tautomeric forms can be distinguished by NMR spectroscopy, IR spectroscopy and other methods. The equilibrium constant tends to be high in nonpolar solvents; when ''K''keto→enol is equal or greater than 1, the enol form is favoured. The keto form becomes more fav ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
