Anionic carbonyl

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

The reactivity of these metal hydride-metal carbonyl reactions can be correlated with the nature of the reactants in a manner consistent with the proposed mechanism nucleophilic attack by hydride on coordinated CO. Thus reactions involving the highly nucleophilic group IV hydride, Cp gZrHg, are much faster than those of group V metal hydrides. On the other hand, the relatively electrophilic neutral binary metal carbonyls all react with Cp2NbH under mild conditions (20-50° C), whereas more electron-rich complexes such as cyclopentadienylmetal carbonyls (Cp2NbH(C0), CpV(CO) ) or anionic carbonyls (V(CO)g ) show no reaction under these conditions. 

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. 

Anilinocyclophosphazene, 21 72 Anionic carbonyl cluster, reaction with cationic mononuclear complexes, 30 155-158... 

One of the most important factors for successful diastereoselection in chiral amide enolate alkylation reactions is the presence of strongly chelated ionic intermediates1 3. The chelation serves the purpose of locking the chiral auxiliary in a fixed position relative to the enolate. The metal counterion is chelated between the enolate oxygen and an additional polar group, anionic, carbonyl or ether oxygen attached to the chiral auxiliary. 

Several nitrosyl complexes have been prepared by the reaction of nitrosyl chloride with anionic carbonyls. Thus, [W(CO)5Cl]- reacts with NOC1395 to give [W(CO)4(NO)Cl] while [W(NO)Cl2L] and [W(NO)2ClL] (L = RB(Pz)3) were prepared from [LW(CO)3]- with variable amounts of NOC1. [W2(CO)8CL,] also reacts with NOQ to give in addition to [W(NO)2Cl2] the mononitrosyl [W(NO)Cl3]393 which exhibits only one v(NO) bond at 1590 cm-1. 

I hope to have shown in this review that our work on reactions in liquid NH3 has contributed to the development of the preparative chemistry of metal carbonyls, especially in the field of anionic carbonyl met-alates, and that it has initiated new impulses and ideas for further advances in this still very active area of organometallic chemistry. 

Iron (II) complex compounds, anions, carbonyl, H2Fe(CO)4, and potassium salt, 2 243, 244... 

Anionic carbonyl clusters with interstitial main-group atoms... 

P. Chini, Synthesis of Large Anionic Carbonyl Clusters as Models for Small Metallic Crystallites, Gazz. Chim. Ital. 109, 225-240 (1979). 

There are relatively few examples of cationic and anionic carbonyl halides containing monoden-tate P, As or Sb donor ligands. Reaction of [Ru(CO)3(PPh3)2] with I2 or Snl4 gives... 

When an aqueous solution of K2Se03 is treated with 1 eq Fe(CO)5/KOH in methanol, an anionic carbonyl species that decomposes in solution to Fe2Se2(CO)6 (77) is observed to be formed. 77 can be isolated as the [PhCH2NMe3]+ salt and has been characterized as [PhCH2NMe3] [Se6Fe6(CO)12] (78) (Fig. 26). 

The performance of four different anionic carbonyl clusters in the hydrogenation of styrene, viz [HFe3(CO)n], [HWOs3(CO)i4] , [H3Os4(CO)i2] and... 

According to electron counting rules, the electrophilic addition of [M(MeCN)] and [M(PPh3)] fragments to anionic carbonyl clusters... 

A few homometallic HNCC have also been produced by the condensation reactions of anionic carbonyl clusters with cationic complexes. For instance, sequential buildup of rhodium HNCC via incorporation of Rh(CO)2 fragments has been achieved by reacting [Rh(CO)2(MeCN)2] in acetonitrile with a series of anionic rhodium clusters as illustrated by the reactions shown in Eqs. (11) and (12) (223). 

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