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The isolobal principle and application of Wades rules

In a condensed polyhedral cluster, two or more polyhedral cages are fused together through atom, edge or face sharing. [Pg.821]

The syntheses of high-nuclearity metal carbonyl clusters are not readily generalized, and we focus only on the structures [Pg.821]

In Section 13.11, we introduced Wade s rules to rationalize the structures of borane and related clusters. This method of counting electrons can be extended to simple organome-tallic clusters by making use of the isolobal relationship between cluster fragments. [Pg.821]

Two cluster fragments are isolobal if they possess the same frontier orbital characteristics same symmetry, same number of electrons available for cluster bonding, and approximately the same energy. [Pg.821]

Os5(CO)i8, in which the Os atoms form a planar raff [W. Wang et al. (1992) J. Chem. Soc., Chem. Commun., p. 1737]. Colour code Os, yellow C, grey O, red. [Pg.822]

Worked example 23.3 Application of Wade s rules (PSEPT) [Pg.715]

Using Wade s approach, rationalize why Co4(CO)j2 has a tetrahedral core. [Pg.716]

The cluster Co2(CO)jC2H2 has a tetrahedral C02C2 core. How many electrons does each CH unit contrihute to cluster bonding lAns. 3  [Pg.716]

V = number of valence electrons from the metal atom  [Pg.905]

This example illustrates an important point about the use of such electron-counting schemes no information about the positions of the ligands can be obtained. Although Wade s rules rationalize why Rh4(CO) 2 and lr4(CO)i2 both have tetrahedral cores, they say nothing about the fact that the ligand arrangements are different (Figs. 24.11a and b). [Pg.905]




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Application Principles

Isolobal

Isolobal principle

Principles and Applicability

The rule

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