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Difluorine Complex
A difluorine complex is a molecular complex involving a difluorine molecule (F2) and another molecule. The first example was gold heptafluoride (AuF7). Instead of being a gold(VII) compound, AuF7 is an adduct of gold pentafluoride (AuF5) and F2. This conclusion has been repeatedly supported by calculations. Unlike dihydrogen complexes, which feature η2-H2, difluorine complexes feature "end-on" or η1-F2 ligand In coordination chemistry, a ligand is an ion or molecule (functional group) that binds to a central metal atom to form a coordination complex. The bonding with the metal generally involves formal donation of one or more of the ligand's elect .... See also * dihydrogen complex References Fluorine compounds {{Coordination complexes ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gold Heptafluoride
Gold heptafluoride is a gold(V) compound with the empirical formula AuF7. The synthesis of this compound was first reported in 1986. However, current calculations suggest that the structure of the synthesized molecule was actually a difluorine ligand on a gold pentafluoride core, AuF5·F2. That would make it the first difluorine complex and the first compound containing a fluorine atom with an oxidation state of zero. The gold(V)–difluorine complex is calculated to be 205 kJ/mol more stable than gold(VII) fluoride. The vibrational frequency A molecular vibration is a periodic motion of the atoms of a molecule relative to each other, such that the center of mass of the molecule remains unchanged. The typical vibrational frequencies range from less than 1013 Hz to approximately 1014 ... at 734 cm−1 is the hallmark of the end-on coordinated difluorine molecule. References Fluorides Metal halides Gold–halogen compounds Substances discovered in the 1980s [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gold Pentafluoride
Gold(V) fluoride is the inorganic compound with the formula Au2F10. This fluoride compound features gold in its highest known oxidation state. This red solid dissolves in hydrogen fluoride but these solutions decompose, liberating fluorine. The structure of gold(V) fluoride in the solid state is centrosymmetric with hexacoordinated gold and an octahedral arrangement of the fluoride centers on each gold center. It is the only known dimeric pentafluoride, although sulfur can form disulfur decafluoride; other pentafluorides are monomeric ( P, As, Sb, Cl, Br, I), tetrameric ( Nb, Ta, Cr, Mo, W, Tc, Re, Ru, Os, Rh, Ir, Pt), or polymeric ( Bi, V, U). In the gas phase, a mixture of dimer and trimer in the ratio 82:18 has been observed. Gold pentafluoride is the strongest known fluoride ion acceptor, exceeding the acceptor tendency of even antimony pentafluoride. Synthesis Gold(V) fluoride can be synthesized by heating gold metal in an atmosphere of oxygen and fluo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Difluorine
Fluorine is a chemical element with the symbol F and atomic number 9. It is the lightest halogen and exists at standard conditions as a highly toxic, pale yellow diatomic gas. As the most electronegative reactive element, it is extremely reactive, as it reacts with all other elements except for the light inert gases. Among the elements, fluorine ranks 24th in universal abundance and 13th in terrestrial abundance. Fluorite, the primary mineral source of fluorine which gave the element its name, was first described in 1529; as it was added to metal ores to lower their melting points for smelting, the Latin verb meaning 'flow' gave the mineral its name. Proposed as an element in 1810, fluorine proved difficult and dangerous to separate from its compounds, and several early experimenters died or sustained injuries from their attempts. Only in 1886 did French chemist Henri Moissan isolate elemental fluorine using low-temperature electrolysis, a process still employed for modern pr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dihydrogen Complex
Dihydrogen complexes are coordination complexes containing intact H2 as a ligand. They are a subset of sigma complexes. The prototypical complex is W(CO)3( PCy3)2(H2). This class of compounds represent intermediates in metal-catalyzed reactions involving hydrogen. Hundreds of dihydrogen complexes have been reported. Most examples are cationic transition metals complexes with octahedral geometry. Upon complexation, the H−H bond is extended to 0.81–0.82 Å as indicated by neutron diffraction, about a 10% extension relative to the H−H bond in free H2. Some complexes containing multiple hydrogen ligands, i.e. polyhydrides, also exhibit short H−H contacts. It has been suggested that distances 1 Å are better described as dihydride complexes (see figure). Characterization The usual method for characterization is 1H NMR spectroscopy. The magnitude of spin-spin coupling, ''J''HD, is a useful indicator of the strength of the bond between the hydrogen and deuterium ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ligand
In coordination chemistry, a ligand is an ion or molecule ( functional group) that binds to a central metal atom to form a coordination complex. The bonding with the metal generally involves formal donation of one or more of the ligand's electron pairs, often through Lewis bases. The nature of metal–ligand bonding can range from covalent to ionic. Furthermore, the metal–ligand bond order can range from one to three. Ligands are viewed as Lewis bases, although rare cases are known to involve Lewis acidic "ligands". Metals and metalloids are bound to ligands in almost all circumstances, although gaseous "naked" metal ions can be generated in a high vacuum. Ligands in a complex dictate the reactivity of the central atom, including ligand substitution rates, the reactivity of the ligands themselves, and redox. Ligand selection requires critical consideration in many practical areas, including bioinorganic and medicinal chemistry, homogeneous catalysis, and environment ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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