Arsine complexes cobalt

Table SO Preparations Some Cobalt-Arsine Complexes... 

A similar reaction occurs with low valent cobalt complexes with diarsines and tetra-arsines [38]. For example, 1 1 peroxo complexes can be prepared by reaction of cobalt(I) arsine complexes with molecular oxygen, equation (6) [38]. The same type of complex is formed by reaction of a Co(III) arsine complex with hydrogen peroxide [38]. Treatment of a Co(II) arsine complex with dioxygen, however, leads to the formation of a /x-peroxo species, equation (6) [38]. 

Although trialkyl- and triarylbismuthines are much weaker donors than the corresponding phosphoms, arsenic, and antimony compounds, they have nevertheless been employed to a considerable extent as ligands in transition metal complexes. The metals coordinated to the bismuth in these complexes include chromium (72—77), cobalt (78,79), iridium (80), iron (77,81,82), manganese (83,84), molybdenum (72,75—77,85—89), nickel (75,79,90,91), niobium (92), rhodium (93,94), silver (95—97), tungsten (72,75—77,87,89), uranium (98), and vanadium (99). The coordination compounds formed from tertiary bismuthines are less stable than those formed from tertiary phosphines, arsines, or stibines. 

The complex reacts readily with ligands such as tertiary phosphines, phosphites, or arsines to give substitution of a CO ligand on the cobalt atom. With CO, however, the complex reacts to give 2-phenylindazolone and 3-phenyl-2,4 lif, 3f/)-quinazolinedione,15 whereas the reaction with CO and hexafluoro-2-butyne affords an anilinoquinoline, probably via an intermediate complex in which the alkyne and CO have inserted into the Co—C bond.16... 

C1bHi5As, Arsine, triphenyl-iron complex, 26 61 C H 5OjP, Triphenyl phosphite ruthenium complex, 26 178 CuHijP, Phosphine, triphenyl-cobalt complex, 26 190—197 cobalt-gold-ruthenium, 26 327 gold complex, 26 90, 325, 326 gold-manganese complex, 26 229 iridium complexes, 26 117-120, 122-125, 201, 202... 

The iron compound readily sublimes and yields well-formed, black lustrous crystals. The cobalt complex will also readily sublime, but dependent upon the temperature at which the crystals are formed, they can be either black or brown in color. The crystal structures of both the cobalt and iron complexes have been determined.3 The nickel complex sublimes only in small amounts with difficulty. All three complexes are unstable to air and water, and the nickel complex readily undergoes thermal decomposition above 100°C. All three compounds will also readily form complexes with a variety of donor ligands such as tertiary arsines or phosphines. The nickel compound usually forms 2 1 adducts such as [(C6HS )3P]2Ni(NO)I, while the iron and cobalt complexes often undergo disproportionation.5... 

With the ligand dbp similar reactions yielded CoCl(dbp)3 and Co(dbp)4, but no Co(BH4)(dbp)3. Triphenyl-arsine and -stibine and CoCl2 were reduced to black products, probably cobalt metal. From NaBH3CN is afforded a Co(BH3CN)(Ph2-PCH2CH2PPh2) complex, but this does not subsequently yield a dinitrogen complex. 

Interferences Metals or salts of metals such as chromium, cobalt, copper, mercury, molybdenum, nickel, palladium, and silver may interfere with the evolution of arsine. Antimony, which forms stibine, is the only metal likely to produce a positive interference in the color development with the silver diethyldithiocarbamate. Stibine forms a red color with silver diethyldithiocarbamate that has a maximum absorbance at 510 nm, but at 535 to 540 nm, the absorbance of the antimony complex is so diminished that the results of the determination would not be altered significantly. 

Reaction of [Co2(ju-alkyne)(CO)6] complexes with monodentate phosphines, phosphites, and arsines results in carbonyl ligand substitution.51,52 One or both axial carbonyl groups can be displaced under thermal conditions. This has been confirmed in a number of cases by X-ray crystallography, for example, [Co2(jU-HC2H)(CO)4(PMe3)2] (Fig. 6).53 The structure inherited from the parent compound is not greatly affected by substitution. The molecule still possesses C2v symmetry and the cobalt-cobalt bond... 

There is no firm evidence for the structure of the initial protonated species, but, bearing in mind that the HOMO of a /<-peroxo complex is essentially a jTg orbital of dioxygen (Sect. D), and on the basis of other structural evidence, it seems probable that the proton is bound to one oxygen only. The structure of the final isomerised product has been determined by X-ray crystallography Protonation of a /<-peroxo complex of cobalt with tertiary arsine ligands has also been reported ... 

Diiron enneacarbonyl, synthesis 46 Triiron dodecacarbonyl, synthesis 46 Tricarbonyl(cyclooctatetraene)iron, synthesis 47 Iron carbonyl complexes of triphenylphosphine, triphenyl-arsine, and triphenylstibine, synthesis 48 cis-Dinitrobis(ethylenediamine)cobalt(III) nitrite and nitrate, synthesis 60... 

Bis-3,4-(trifluoromethyl)-l,2-diselenete 651 is prepared by refluxing selenium with hexafluoro-2-butyne. It reacts with triphenylphosphine and triphenyl-arsine. Triphenylphosphine selenide was isolated, but no other compounds were identified.Ring-opened complexes with nickel, copper, vanadium, molybdenum (652), tungsten, iron, and cobalt are analogous to complexes of the 1,2-dithiete (527) (Section XXXV.2.C.). 

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