Coordination compounds oxidation state

Coordination complexes are a remarkably diverse group of molecules that form from virtually all transition metals In a variety of oxidation states. These compounds involve an extensive array of ligands, and they adopt several molecular geometries. 

Phosphorus compounds, 19 19-73 bond properties of, 19 26 chemical properties of, 19 20-31 chiral-centered, 19 25-26 economic aspects of, 19 67-69 as flame retardants, 19 51 inorganic, 11 487-488 oxidation states, coordination numbers, and geometries of, 19 20-26 as oxyacid derivatives, 19 20 reactive organic, 11 496 497 titanium in, 25 56-57 triply connected, 19 25 U.S. prices of, 19 68t U.S. production of, 19 67t... 

Crystal Structure and Ionic Radii. Crystal structure data have provided the basis for the ionic radii (coordination number — C-N — 6). For both M3+ and M4 10ns there is an actinide contraction, analogous to the lanthanide contraction, with increasing positive charge on the nucleus. As a consequence of the ionic character of most actinide compounds and of the similarity of the ionic radii for a given oxidation state, analogous compounds are generally isostmctural. 

Noble metal Compounds 4d-metal Sd-metal Metal oxidation state Coordination type... 

Oxidation state Coordination number Coordination geometry Examples of compounds... 

Chromium ions at the surfaces of inorganic oxides are characterized by a wide variability of the oxidation state, coordination number, and local structure. Consequently, Cr-based materials are especially attractive as catalysts. Much is known about the catalytic activity of pure Cr203 for various reactions (469), including polymerization of alkenes (470-472), hydrogenation-dehydrogenation of hydrocarbons (473-481), reduction of NO and decomposition of N2O4 (482), and oxidation of organic compounds (483, 484). 

Low-oxidation state iron compounds are stabilized by electron acceptor ligands, especially carbon monoxide, isocyanide, and phosphorus donors. The most common coordination geometry encountered in iron compounds is octahedral, but tetrahedral, trigonal bipyramidal, and square pyramidal are also represented. There are only a few compounds with iron in the -II state, although reduction of [Fe(CO)s] with sodium amalgam in THF... 

The chemistry of cobalt involves mainly its +2 and +3 oxidation states, although compounds containing cobalt in the 0, +1, or +4 oxidation states are known. Aqueous solutions of cobalt(II) salts contain the Co(H20)62+ ion, which has a characteristic rose color. Cobalt forms a wide variety of coordination compounds, many of which will be discussed in later sections of this chapter. Some typical cobalt compounds are listed in Table 20.8. 

The earliest isolated organotin species in which the tin atom is in the II+ formal oxidation state are compounds in which the tin atom acts as a Lewis base that coordinates to a suitable transition metal fragment,... 

Bismuth, Bi, the 83rd element of the periodic table is the most metallic and the least abundant of the elements in the nitrogen family (group 15). It has an atomic mass of 208.980 and a ground state electronic configuration of [Xe] 4f 5d %s 6p. The bismuth atom usually utilizes the three 6p electrons in bond formation and retains the two 6s electrons as an inert pair, hence the oxidation state -1-3 exhibited by bismuth in the vast majority of its compounds. However, a variety of organobismuth compounds can contain the element in the -1-5 oxidation state. Coordination numbers are 2, 3,4, 5 and 6. Bismuth not only has metallic characteristics but also exhibits many properties similar to those of semiconductors and insulators. Consequently, it is often classified as a semi-metal or metalloid. Bismuth compounds are usually colorless unless the metal is bound to a chromophore. 

Coordination number. The coordination number is the number of ligand atoms bonded directly to the central metal ion and is specific for a given metal ion in a particular oxidation state and compound. In general, the most common coordination number in complex ions is 6, but 2 and 4 are often seen, and some higher ones are also known. 

Metal-catalyzed hydrogenations, carbonylations, hydroformylations, etc. involve transition metals in low oxidation states coordinated to soft ligands, e.g., phosphines, as the catalytically active species and organometallic compounds as reactive... 

Oxidation state Coordination number Geometry Compound... 

This type of addition takes place in the case of complexes in which the metal possesses a low oxidation state. Coordinatively saturated complexes (18e) or compounds with a coordination number lower than the maximum (e.g., 16c) may be utilized ... 

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