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Tantalum-Carbon Bond. Organotantalum chemistry is the chemistry of chemical compounds containing a carbon-to-tantalum chemical bond. A wide variety of compound have been reported, initially with cyclopentadienyl and CO ligands. Oxidation states vary from Ta(V) to Ta(-I).
The oxidation states are also maintained in articles of the elements (of course), and systematically in the table {{Infobox element/symbol-to-oxidation-state}} See also [ edit ]
The standard Gibbs free energy of formation (G f °) of a compound is the change of Gibbs free energy that accompanies the formation of 1 mole of a substance in its standard state from its constituent elements in their standard states (the most stable form of the element at 1 bar of pressure and the specified temperature, usually 298.15 K or 25 °C).
Tantalum halides span the oxidation states of +5, +4, and +3. Tantalum pentafluoride (TaF 5 ) is a white solid with a melting point of 97.0 °C. The anion [TaF 7 ] 2- is used for its separation from niobium. [ 41 ]
8, has been described as having a carbon oxidation state of − 8 / 3 . [19] Again, this is an average value since the structure of the molecule is H 3 C−CH 2 −CH 3, with the first and third carbon atoms each having an oxidation state of −3 and the central one −2.
As quoted from this source in an online version of: J.A. Dean (ed), Lange's Handbook of Chemistry (15th Edition), McGraw-Hill, 1999; Section 4; Table 4.1, Electronic Configuration and Properties of the Elements Touloukian, Y. S., Thermophysical Properties of Matter, Vol. 12, Thermal Expansion, Plenum, New York, 1975.
In the temperature ranges commonly used, the metal and the oxide are in a condensed state (solid or liquid), and oxygen is a gas with a much larger molar entropy. For the oxidation of each metal, the dominant contribution to the entropy change (Δ S ) is the removal of 1 ⁄ 2 mol O
Although thermodynamically prone to oxidation, carbon resists oxidation more effectively than elements such as iron and copper, which are weaker reducing agents at room temperature. Carbon is the sixth element, with a ground-state electron configuration of 1s 2 2s 2 2p 2, of which the four outer electrons are valence electrons. Its first four ...