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Isolobal analogy principle

The addition of transition metal fragments ML (L = two-electron donor ligand) across formally unsaturated metal-metal or metal-carbon bonds is a well-developed synthetic route to heteronuclear clusters (1,2,11,12,27) and has received theoretical justification from Hoffmann s isolobal principle (46). The addition of a PtL2 fragment across an M=M double bond may be considered as analogous to the reaction of a carbene with an olefin, resulting in a cyclopropane. The use of isolobal analogies in the directed synthesis of heteronuclear clusters has been reviewed (11,12,27). [Pg.304]

The isolobal analogy [9,10] tells us that this n + 1)-SEP rule can be in principle extended to any type of closo skeleton made of fragments possessing a similar set of 3 FOs (see Fig. 1), irrespectively of their energy and precise shape or composition. This is indeed the case of many transition-metal carbonyl or phosphine organome-tallic clusters, most of them built from conical ML3 fragments. For example, the three octahedral clusters [BeHe], [Ru6(CO)ig] [46], and [Ru4(CO)i2Bi2] [47] are 7-SEP species. ... [Pg.162]

Hoffmann s isolobal analogy is a general unifying principle that goes far beyond the confines of cluster chemistry. Nevertheless it has found most... [Pg.348]

Hoffmann s isolobal analogy is a unifying principle that identifies analogies between organic and inorganic structures in terms of their bonding pattern. Different L M groups are considered isolobal with... [Pg.364]

Using the isolobal principle, one can relate clusters that contain fragments having analogous orbital properties. Some isolobal pairs of metal carbonyl and hydrocarbon fragments are ... [Pg.716]

Certain L M fragments are often considered carbene-like because there is an analogy between their insertion into X—Y bonds and the insertion of an organic carbene, such as CH2, into a C—H, Si—H, or O—H bond (Eq. 3.17). In Section 13.2, we will see how the isolobal principle allows us to understand the orbital analogy between the two systems. There are several mechanisms... [Pg.51]


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