Platinum group metals, coordination compounds

Hydroformylation - [CARBON MONOXIDE] (Vol 5) - [OXO PROCESS] (Vol 17) -of allyl alcohol [ALLYL ALCOHOL AND MONOALLYL DERIVATIVES] (Vol 2) -catalysts for [CATALYSIS] (Vol 5) -C-19 dicarboxylic acids from [DICARBOXYLIC ACIDS] (Vol 8) -of ethylene [ETHYLENE] (Vol 9) -of ethylene [PROPYL ALCOHOLS - N-PROPYLALCOLHOL] (Vol 20) -of maleate and fumarate esters [MALEIC ANHYDRIDE, MALEIC ACID AND FUMARIC ACID] (Vol 15) -phosphine catalyst [PHOSPHORUS COMPOUNDS] (Vol 18) -platinum-group metal catalysts for [PLATINUM-GROUP METALS] (Vol 19) -rhodium catalysis [PLATINUM-GROUP METALS, COMPOUNDS] (Vol 19) -ruthenium cmpds or catalyst [PLATINUM-GROUP METALS, COMPOUNDS] (Vol 19) -use of coordination compounds [COORDINATION COMPOUNDS] (Vol 7)... 

Isomerization of olefins—redistribution of carbon-carbon double bonds—often occurs in the presence of transition metal complexes such as metal earbonyls, platinum group metal ions, and silver(I) compounds. It appears that sueh catalytic activity has two requirements. (1) The metal complex must contain labile ligands that can easily be displaced by an olefin to form a vr-complex or must be able to easily expand its coordination. (2) The metal complex must be kinetically labile so tha t the isomerized olefin can be displaced by another olefin to continue the cycle. 

Organorhodium compounds are found in oxidation states ranging fi-om +6 to -3. However, the most conunon oxidation states are +1 and +3. Rh(I) species exist as both a tetra-coordinated, square planar complex as well as a penta-coordinated trigonal bipyramidal complex. Rhodium, like platinum group metals, exhibits reversible oxidation states making a broad range of organic-catalytic transformations possible. 

Fig. 13.2 Two- and three-dimensional structures of platinum-based chemotherapeutic drugs. Cisplatin, the first of the so-caUed organoplatinum drugs, contains no organic component. It is a metal coordination compound with a square-planar platinum (II) center coordinated to two ammonia and two chlorine ligands in a cw-ligand conformation. Carboplatin contains the CM-Pt(NH )2 active group...

Using a series of new coordination compounds of some platinum group metals with potentially hemilabile redox-active chelate ligands based on the o-benzosemiquinoneimine intermediate, the extent of noninnocent behavior has been established experimentally, via structure determination and EPR, UV-vis-NIR spectroelectrochemistry [35, 36], and computationally... 

A coordination compound is a compound in which a central metal ion (or atom) is attached to a group of surrounding molecules or ions by coordinate covalent bonds. A good example is the anticancer drug dsplatin, Pt(NH3)2Cl2, in which two NH3 molecules and two Cl ions use lone pairs of electrons to bond to the platinum(II) ion ... 

A tetrahedral platinum atom was not possible in these molecules, since the isomers were not optically active. The direct linking to the metal of the non-metallic groups added in the formation of these supposed molecular compounds was known as coordination and the resulting molecules were coordination compounds. Molecules that we consider coordination compounds today include hemoglobin and chlorophyll, which are vital to animal and plant life. 

The reaction of platinum dioxide with other metal dioxides can be separated into three groups—i.e., compounds with metal-oxygen coordination numbers of 4 2, 6 3, and 8 4. We have investigated only a single... 

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