Flash photolysis alkane activation

The formation of diphenylcarbene by laser flash photolysis of diphenyldiazomethane was studied in SC-CO2 and other supercritical media. [18] A laser-flash induced ring-closure reaction of a bipyridyl complex (Scheme 2) revealed solvation properties. [19] Laser-flash impact to metal carbonyl complexes activated hydrogen and simple alkanes like CH4, C2H4, C2H6, and further inorganic reactions in supercritical fluids have been reviewed. [20]... 

Laser flash photolysis of [CpIr(CO)2] results in the activation of alkanes in inert CgFg solvent. A study under these conditions revealed the anticipated preference for the activation of aromatic and unhindered C—H bonds on the basis of quantum yields (< ). It also implied the unexpected mechanism shown in Scheme 4. Added CO has virtually no effect on . Moreover the use of r/ -indenyl instead of Cp increases (f>. 

Although the developments of alkane/noble gas chemistry and G-H activation have continued to occur, in parallel, we will focus initially on the cr-coordination of the alkane before looking at oxidative addition. Flash photolysis of... 

In Section 2.3.5 we saw that 2.67, an iridium analogue of 3.10, on photolysis loses a CO and activates an alkane by oxidative addition (see (2.3.5.2)). Intermediates that precede oxidative addition are expected to be short-lived. Their spectroscopic identification therefore requires an inert solvent and a technique fast enough to identify such short-lived intermediates. Low-temperature ultraviolet (UV) flash photolysis of 3.10 in liquid krypton doped with cyclohexane or neopentane has been studied by time-resolved IR. These experiments show that transient intermediates 3.11 and 3.12 are generated under these conditions. 

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