Tetrachloroiodate anion

Term symbols, 26-27, A7-A12 Tetrachloroiodate anion. 209 Tetragonal crystal system, 75, 78 Tetragonal symmetry. 403-404 Tetrahedral complexes, 401-403, 418-420, 441. 448-455, 474-477... 

The associative pathway of ligand exchange starts from the addition of a nucleophile to the positively charged iodine atom of a X -iodane with the initial formation of a trans hypervalent 12-1-4 square-planar species. This intermediate species isomerizes to the cis 12-1-4 square-planar intermediate and eliminates the ligand L to afford the final product (Scheme 1.4). Such a mechanism has been validated by the isolation and X-ray structural identification of several stable 12-1-4 species. For example, the interaction of ICI3 with chloride anion affords tetrachloroiodate anion, ICl4, which has a distorted square-planar structure as established by X-ray analysis of the trichlorosulfonium salt, CI3S+ ICU [209]. 

Tetrachloroiodate(IIf) anion (Dih). The MCIJ anion is isoelectronic with the TeFJ ion with respect to the central atom. In this case, however, there are four bonding pairs and two lone pairs. In an undistorted octahedron, all six points are equivalent, and the lone pairs could be adjacent, or cis (Fig. 6.7a) or trans (Fig 6.7b), opposite to one another. In the cis arrangement the lone pairs will compete with each other for volume into which to expand, a less desirable arrangement than trans, in which they can expand at the expense of the bonding pairs. Since the lone pairs are not seen in a normal structural determination, the resulting arrangement of atoms is square planar (Fig. 6.7c). 

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See also in sourсe #XX -- [ ]

See also in sourсe #XX -- [ ]

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