Reactions with Transition Metal Complexes

Some of the complexes listed in Table 9.7 (R = SiMe,) which have a bond or bonds between a transition metal (M ) and a Group 14 metal(II) (M ) amide have been shown to undergo further reactions. The first such reactions (1985, from Sussex) are shown in 

Equation (9.23) (cf. Table 9.7)/47a,247b crystalline products have a planar [MM (CO)]3 core and in thf ey underwent reversible electrochemical 1-electron reduction which for the Pt/Sn product was shown by EPR spectroscopy (subsequent to controlled potential electrolysis) to retain its (PtSn) , framework.  

The most detailed studies of reactions of M -M amide) compounds were carried out by Banaszak HoU and coworkers (1995-2004), as summarised in Table 9.8. These dealt with 

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The heterocycles can be cleaved by reaction with 4-(dimethylamino)pyri-dine, yielding Lewis base-stabilized monomeric compounds of the type dmap—M(R2)E(Tms)2 (M = Al, Ga E = P, As, Sb, Bi). This general reaction now offers the possibility to synthesize electronically rather than kinetically stabilized monomeric group 13/15 compounds. These can be used for further complexation reactions with transition metal complexes, leading to bimetallic complexes of the type dmap—M(Me2)E(Tms)2—M (CO) (M = Al, Ga E = P, As, Sb M = Ni, Gr, Ee). 

Studies related to the mechanisms of nitric oxide reactions with transition metal complexes in this laboratory were supported by grants from the U.S. National Science Foundation, by a Collaborative UC/Los Alamos National Laboratory Research grant, by a grant from the U.S. Japan Cooperative Research Program (Photoconversion/ Photosynthesis) (NSF INT 9116346), and by a grant from the ACS Petroleum Research Fund. We thank the students and postdoctoral fellows at UC Santa Barbara who participated in this research and acknowledge collaborative studies with Dr. David Wink (National Cancer Institute, Bethesda MD, USA), Dr. Mikio Hoshino (RIKEN, Wako-shi, Japan) and Dr. Jon Schoonover (Los Alamos National Laboratory). 

In contrast to the biological CO2 fixation during the dark reaction of photosynthesis where very low concentrations of CO2 from air can be fixed at room temperature, most reactions with transition-metal complexes or with organic substrates either require high partial pressure of CO2 or high temperatures. An exception was published quite recently, the rapid fixation of CO2 and O2 from air at a palladium(O) complex 10 (Scheme 11) [77]. 

A recent review discusses the chemistry of ylides and their reactions with transition metal complexes.425 This article integrates platinum yhde chemistry with that of other metal ions, and has sections covering bonding. 

Attempt to prepare Jt-complexes of triafulvenes and related methylene cyclopro-parenes285,427 428 directly by ligand exchange reaction with transition metal complexes resulted in metal insertion into the sigma bond, forming metallacyclic complexes. Thus reaction of the electron-poor triafulvene l,2-diphenyl-3-dicyanomethylenecyclopropene with (ethylene)bis(triphenylphosphine)platinum in refluxing benzene gave two crystalline products whose platinacyclobutene structure was confirmed by X-ray structure analysis (equation 364)429. 

For other very useful reactions of alkynyl-A3-iodanes involving Diels-Alder reactions, 1,3-dipolar cycloadditions, and reactions with transition metal complexes, see the excellent reviews of Koser [39] and Stang [208,209]. 

A similar situation is encountered in reactions with transition metal complexes where the fullerenes behave much like large olefins. For example, the addition of Vaska-type iridium complexes, such as Ir(CO)Cl(PR3)2, to fullerenes which has proven to be an effective way of obtaining materials that are suitable for crystallographic studies 88... 

The chemistry of Ge-transition metal compounds is a field experiencing relatively fewer studies. However, varieties of such compounds have been prepared and characterized. In reactions with transition metal complexes, Ge behaves as a... 

In their reactions with transition metal complexes, free radicals may attack directly at the metal center or at a ligand to produce a coordinated free radical, which may then undergo electron transfer involving the metal center. The first observation... 

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