Perchlorato complex

Cunin, F., Deudon, C., Favier, F., Mula, B. and Pascal, J.L. (2002) First anhydrous gold perchlorato complex CIO2AU (0104)4. Synthesis and molecular and crystal stmcture analysis. Inorganic Chemistry, 41, 4173. 

In Sect. 5.2, the strong 7r-donor ability of methoxide and fluoride has been elaborated. These two ligands effect a push-pull effect on the nitrosonium ion bound in Os(OEP)NO(OMe) [31c] and Os(OEP)NO(F) [3Id], as indicated by the low NO-stretching frequencies of the NO ion as compared with the dinitrosyl Os(OEP)(NO)2 [31e] and the perchlorato complex, 0s(0EP)N0(0C103) ([3If], Table 11). Thus, the a/7r-donor balance for the coordinated anions decreases in the series OMe > F > NO > OClOf. [31c] and [3Id] can be vaporized at 200°C/10-6 Torr in a mass spectrometer, while the dinitrosyl [31e] decomposes above 100 °C. This demonstrates the push-pull effect also in a chemical sense. 

Table 84 Infrared Absorption Frequencies of some Perchlorato Complexes...

It is evident that a majority of the metals form perchlorato complexes provided care is taken to eliminate from the system water and other anions, especially halides. The O—Cl bond of the M—O—Cl unit... 

In the second, slower process, the perchlorato complex undergoes solvolysis,... 

Tetrahedral perchlorate ion, [C104] , is an uncommon ligand.1 The molecular perchlorato complexes of iridium and rhodium2 described here are thus of inherent interest as such, but their principal importance lies in their versatile reactivity. These compounds undergo addition, substitution, and addition-substitution reactions with many molecules and ions.3 In particular, the latter conversions lead to a remarkable number of cationic d8 complexes of these metals, which offer themselves as a unique series for a study of the electronic properties of a variety of molecules as ligands (L).3 Not less significant are the substitution reactions in which the perchlorate ligand is replaced by other unusual anions.4... 

The present preparative procedure for perchlorato complexes of rhodium and iridium appears to be of general utility for the synthesis of perchlorato complexes of transition metals. The assignment of trans planar structures for [M(OC103)(CO)(Ph3P)2] (M = Ir, Rh) is based on the vibrational and electronic spectral similarities between the perchlorato complexes and their well-known chloro precursors, tims-[MCl(CO)(Ph3P)2].5,6... 

Caution. Although no explosions have occurred with these perchlorato complexes, these compounds are potentially very hazardous. Adequate shielding and protective clothing should be worn when handling them.1... 

The starting complex is not completely soluble in this quantity of the solvent. The remaining solid portion dissolves during the reaction to give the more soluble perchlorato complex. Larger volumes of benzene reduce the yield of the solid product. 

Cobalt chemistry, nowadays, might be regarded by some as unfashionable but its importance, both historical and current, is undeniable, as demonstrated by the work outlined in this chapter. Cobalt will always retain its capacity to surprise, as evidenced by the recent serendipitous isolation of both [Co(tmen)(OH2)(H)](N03)(C104) C2H50H (33), a hydride complex that can be recrystallized from 5 M aqueous HC104 and (34), a carbanionic perchlorato complex isolated from aqueous solution.We await further developments in cobalt chemistry with interest. 

Ligands Containing O-Cl Bonds - The perchlorato-complex Co(C104)2L, where L = Ph2PCH28iMe2CH2PPh2, gives IR bands due to unidentate perchlorate, at 920 cm (vi) and440cm (v6)42 ... 

The achievement of a high CN for the R(III) ion is also an important requirement. For instance, mixed perchlorato complexes with 2CA and 15C5 (CN = 9) do not form for La and Ce, because the 1 2 15C5 coronates (CN = 10) are much more stable and steric hindrance prevents any CIO4 association. 

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