Anionic carbonyl complexes

Anionic carbonyl complexes of both rhodium(I) and (III) are synthesized by decarbonylation of formic acid, with reduction to rhodium(I) occurring... 

Reactions 7 and 8 involve oxidation of rhodium(I) to rhodium(III). Reaction 8 can also be written as an oxidative addition of I2 (formed thermally from 2 HI) to the Rh(I) complex. Rhodium(III) iodide (for convenience written as an anionic carbonyl complex) may precipitate from the reaction medium. It has to be converted to rhodium(I) again. This is done in the acetic acid process by water and carbon monoxide. 

Alkyl and aryl carbonyl complexes of osmium result from the reactions of anionic carbonyl complexes with organic electrophiles. The reactions between Na20s(C0)4 or NaOsH(CO)4 and ROTf, or RI (R = Me, Et) produce... 

Carbonylate Ions NtimeixHis anionic carbonyl complexes, tdso called carbonylatc ions, are known. 

Table 4-2 Positions of Strong C-0 Absorptions in Binary Anionic Carbonyl Complexes...

The anionic carbonyl complex, [Mn(CO)j], is a relatively good nucleophile. When treated with CHjI, it displaces r to form [Mn(CH3)(CO)5] ... 

Numerous anionic carbonyl complexes, alsu culled curbouylaie ions, arc known. These anions generally conform to the 18-cIectron rule and arc or intercsl because Of (he information they provide regarding bonding and structure as well as for Ihetr usefulness in the synthesis of other carbonyl derivatives. They are often electronically and structurally related to neutral carbonyl complexes (Table 15.4). For example. 

This type of reaction may also involve the action of anionic carbonyl complexes on metal alkyl compounds ... 

Anionic carbonyl complexes of iron, ruthenium, chromium, molybdenum, tungsten, etc., also react with 3,4-dichlorocyclobutene or its derivatives. In order to obtain anionic derivatives, metal carbonyls are reduced by means of sodium amalgam [equations (8.29H8.31)]. 

In anionic carbonyl complexes the metal center is often found in a negative oxidation state and this is reflected in the standard potentials of metal carbonyls. Thus, the standard potentials of the following couples are -0.68, -0.40, and -0.74 V, respectively, Eqs. 9.1 - 9.3 ... 

---