Cobalt compounds adduct

Separation selectivity can also be altered by the type of ion that is formed for the compound of interest. Cation or anion adducts can have a significant effect on the separation. In the positive ion mode, most ions formed from electrospray or any chemical ionization methods are protonated cations. However, if Na+ is added to the electrospray solution, sodiated adducts may be formed as the primary response ion. For example, the protonated ions of two isomers, methyl-P-glucopyranoside and methyl-a-glucopyranoside, cannot be baseline separated in DTIMS, but the sodiated adducts of the same isomers can be baseline separated. Figure 8.9 demonstrates separation selectivity induced by cation adduction. These IMS spectra are of the methyl-p-D-galactopyranoside and the methyl-a-D-galactopyranoside isomers adducted with cobalt acetate, silver, and lead acetate. The cobalt acetate adducts had a separation factor of 1.02, the silver adducts had a separation factor of 1.05, and the lead acetate adducts had a separation factor of 1.07. 

The Bu 4-t-indacene ligand afforded a mixture of as- and /raor-isomers of a di(cobalt-Cp) adduct." These neutral compounds 356 and 357 interconverted in solution. The oxidation of these compounds by NH4BF4 afforded the corresponding dicobalticinium derivatives 358 and 359, in which the t-indacene ligand has been protonated at the 4,8-positions. These new complexes did no more interconversion (Equation (60)). 

Recent developments in the studies of molecular oxygen adducts of cobalt(II) compounds and related systems. T. D. Smith and J. R. Pilbrow, Coord. Chem. Rev., 1981, 39, 295-383 (337). 

Diketonate cobalt(III) complexes with alkyl peroxo adducts have been prepared recently and characterized structurally, and their value in hydrocarbon oxidation and olefin epoxidation examined.980 Compounds Co(acac) 2(L) (O O / - B u) with L = py, 4-Mepy and 1-Meim, as well as the analog of the first with dibenzoylmethane as the diketone, were prepared. A distorted octahedral geometry with the monodentates cis is consistently observed, and the Co—O bond distance for the peroxo ligand lies between 1.860(3) A and 1.879(2) A. 

The chemistry of the 1 1 and 1 2 complexes differs with respect to hydrogenation (84,89). The 1 2 derivatives are inert to hydrogenation, while the 1 1 compounds are smoothly transformed into an ethylidene complex (see Scheme 1). This difference in behavior may well reflect the cause of differences in behavior of olefins on metal surfaces toward hydrogenation. The ethylidene complex may be converted back to the olefin adduct by reaction with trityl ion. The ethylidene adduct was first obtained for ruthenium by interaction of ethylene with H RujfCO) (89), and is structurally related to the corresponding cobalt derivatives, Co3(CO)9RC. As discussed above, the structure has been established in detail and involves a capping of the metal triangle... 

Cyclic silylphosphanes, see Silylphosphanes, phosphorus-rich, cyclic Cyclic sulfur-nitrogen compounds, see Sulfur-nitrogen compounds, cyclic Cyclic trithiolate ligand, 38 8-9 Cyclic voltammetry A. chroococcum Fd 1, 38 130-131 fullerene adducts, 44 19 nickel(ll) macrocyclic complexes, 44 112 Rieske proteins, 47 138, 139 Cyclidenes, as cobalt complex ligands, 44 282-284... 

Jeong and co-workers utilized a cobalt-alkyne complex to enhance enantioselectivity of the addition of bis (homoallyl)zinc to propargyl aldehydes 68 by the exaggeration of steric environment. The reaction provided optically enriched propargyl alcohol 69 in the presence of a chiral ligand and titanium tetra(isopropoxide) in excess. Adduct 69 was subjected to PKR to yield optically enriched bicyclic compounds 70 (Equation (39)). ... 

Compounds with Metal-Metal Bonds. There is one clear example of the addition of a compound with a metal-metal bond to an olefin. Cobalt octacarbonyl reacts with tetrafluoroethylene to form a symmetrical adduct (102). 

Thiadiazole forms easily hydrolyzed salts with mineral acids, a methiodide, and 1 1 addition compounds with silver nitrate and mercuric and cobaltous chlorides.5 Its weakly basic properties are shared by its homologs14,22 which form salts and adducts similarly. 

In this work, 1 1 oxygenated low-spin cobalt(II)-ammonia complexes were synthesized within the zeolite framework by the adsorption of NH3 and 02 in Co(II)Y zeolites with differing cobalt(II) content. Spin densities and the nature of the superoxide anion (02 ) were estimated by introducing oxygen-17 in the ammoniated Co(II) zeolites. Questions concerning the equivalence of the two oxygen atoms have arisen in studies on oxygen adducts of Co (II) Schiff base compounds (7), and it was of interest to study this problem in cobalt(II) ammonia complexes. 

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... 

The examined compound behaves as an N,Te-donor ligand also in analogous cobalt and copper complexes [922]. The N,Te-ligand environment is very likely for complexes 530 [923], 531 [924], adduct 532 [925], and tellurium-containing macrocyclic Schiff bases 533 [926] ... 

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