Transition Metal Complexes of a Constrained Phosphite Ester. IV. Compounds of Cobalt(I), Cobalt(III), Nickel(II), and Nickel(0)

Hüttemann, Thomas; Foxman, Bruce M.; Sperati, C. R.; Verkade, J. G.

doi:10.1021/ic50029a005

Cited by 42 publications

(12 citation statements)

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“…This is due to several different smaller fragments of the corrin ring generated that might coordinate to Co. Colorless Cobalt (II)/(III) complexes have previously reported [44]. The exact nature of the Co-complex is currently under investigation in our laboratory.…”

Section: Resultsmentioning

confidence: 96%

“…In contrast to what was observed for the reaction of hemoproteins and free heme with HOCl where we detected Fe 2+ release [40] – [43] , we were unable to determine the oxidation state of the Co ion and the nature of the axial ligation to the Co after corrin ring destruction by HOCl. This is due to several different smaller fragments of the corrin ring generated that might coordinate to Co. Colorless Cobalt (II)/(III) complexes have previously reported [44] . The exact nature of the Co-complex is currently under investigation in our laboratory.…”

Section: Resultsmentioning

confidence: 99%

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Kinetic Studies on the Reaction between Dicyanocobinamide and Hypochlorous Acid

et al. 2014

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Hypochlorous acid (HOCl) is a potent oxidant generated by myeloperoxidase (MPO), which is an abundant enzyme used for defense against microbes. We examined the potential role of HOCl in corrin ring destruction and subsequent formation of cyanogen chloride (CNCl) from dicyanocobinamide ((CN)2-Cbi). Stopped-flow analysis revealed that the reaction consists of at least three observable steps, including at least two sequential transient intermediates prior to corrin ring destruction. The first two steps were attributed to sequential replacement of the two cyanide ligands with hypochlorite, while the third step was the destruction of the corrin ring. The formation of (OCl)(CN)-Cbi and its conversion to (OCl)2-Cbi was fitted to a first order rate equation with second order rate constants of 0.002 and 0.0002 µM−1s−1, respectively. The significantly lower rate of the second step compared to the first suggests that the replacement of the first cyanide molecule by hypochlorite causes an alteration in the ligand trans effects changing the affinity and/or accessibility of Co toward hypochlorite. Plots of the apparent rate constants as a function of HOCl concentration for all the three steps were linear with Y-intercepts close to zero, indicating that HOCl binds in an irreversible one-step mechanism. Collectively, these results illustrate functional differences in the corrin ring environments toward binding of diatomic ligands.

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Section: Resultsmentioning

confidence: 96%

Section: Resultsmentioning

confidence: 99%

Kinetic Studies on the Reaction between Dicyanocobinamide and Hypochlorous Acid

et al. 2014

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“…With ligands having reducing properties, as isocyanides (127), phosphines (129), and phosphites (106,189), the reduction can be brought about by the ligand itself-usually in ethanolic solution.…”

Section: Spontaneous Reductionmentioning

confidence: 99%

“…This method was used to prepare the tetrakisphosphitenickel(O) derivatives from nickel(II) salts with an excess of the phosphite and a tertiary amine (106,189).…”

Section: By Replacement Of Zerovalent Isocyanide Derivativesmentioning

confidence: 99%

Chemistry of Zerovalent Nickel, Palladium, and Platinum Derivatives

Malatesta¹,

Ugo²,

Cenini³

1967

Werner Centennial

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The chemistry of the zerovalent state in nickel, palladium, and platinum compounds is reviewed. After a historical introduction in which the development of this chemistry is analyzed in terms of the current theory of the stabilization of low valency states, the most interesting classes of zero valent compounds are described. The stability and properties of these compounds are discussed and related to the nature of the ligands and the coordinated metal. The catalytic properties of these zerovalent derivatives toward olefins, diolefins, and acetylenes are considered in connection with the facility of ligands exchange, the varia tion of coordination number, and the stereochemistry. A discussion of the π bond is reported.'he first coordination compound with a low oxidation number, tetracarbonylnickel (HI), was discovered in 1890. Despite extensive efforts, however, very few substances of this type were synthesized in the next 50 years.The lack of any knowledge on the structure and bonds of these com pounds was responsible for the poor results. In fact, when tetracarbonylnickel was first prepared, Werner's theory had not as yet been postulated, and even later the theory was not extended to the carbonyls because they were considered anomalous compounds, owing to their chemical and physical properties.The studies on coordination compounds with the central metal in a low oxidation state began to fluorish just prior to World War II. Nickel, palladium, and platinum were particularly investigated for the following reasons:318

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“…Although considerable work has been done on the coordination chemistry of the bicyclic phosphite compounds I and II (9)(10)(11)(12)(13)(14), there is a notable absence of coordination chemistry of bicyclic phosphines.…”

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confidence: 99%

The preparation of 2,6,7-trioxa-1, 4-diphosphabicyclo [222] octane and the study of some transition metal complexes of trimethyl phosphite

Coskran

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Instrumentation Infrared spectra Infrared spectra were obtained in KBr pellets and CCl^ solutions and recorded on a Perkin-Elmer Model 21 double-beam spectrometer using sodium chloride optics. Nuclear magnetic resonance spectra Proton n.m.r. spectra were obtained on approximately 15% solutions on Varian Associates Models HR-60 and A-60 spectrometers. Tier's salt was used as an internal standard for aqueous solutions and tetramethylsilane for all other solutions. P^^ n.m.r. spectra were obtained on approximately 30% dimethyl sulfoxide solutions with 85% aqueous phosphoric acid as an external standard. Melting points Melting points were taken in capillaries and are uncorrected.

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Transition Metal Complexes of a Constrained Phosphite Ester. IV. Compounds of Cobalt(I), Cobalt(III), Nickel(II), and Nickel(0)

Cited by 42 publications

References 1 publication

Kinetic Studies on the Reaction between Dicyanocobinamide and Hypochlorous Acid

Kinetic Studies on the Reaction between Dicyanocobinamide and Hypochlorous Acid

Chemistry of Zerovalent Nickel, Palladium, and Platinum Derivatives

The preparation of 2,6,7-trioxa-1, 4-diphosphabicyclo [222] octane and the study of some transition metal complexes of trimethyl phosphite

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