Thermal decomposition of COS

The decomposition of CO has been studied in shock tubes14-16 at temperatures in excess of 6000 °K, and in glass vessels17 at temperatures in the region of 1000 °K. The low-temperature pyrolysis is entirely heterogeneous. Fairbairn s studies14 have shown that the assumption adopted by previous workers that the decomposition is controlled by 

RATE COEFFICIENTS OF SOME ELEMENTARY REACTIONS INVOLVED IN CO DECOMPOSITION 

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Although the oxidation of Cr(lII) by Ce(lV) is a rapid reaction in perchlorate solutions, the oxidation of Cr(III) by Co(III) in the same media occurs at a rate similar to or slower than that of the thermal decomposition of Co(lll) in perchloric acid (3 M). However, the Co(lII)- -Cr(III) reaction is subject to catalysis by Ag(I) ion and Kirwin et al have made a kinetic study of this system, viz. 

This is an typical example of a dicarboxylic acid in that C-C cleavage is the only route for oxidation. No study of the Co(III) oxidation has been made although it is highly probable that reaction would proceed through an oxalate complex. The thermal decomposition of Co(Ox)3 has been shown to be a first-order process and probably involves an internal redox reaction, viz. 

This oxoacidity is described by p02 = - log a(02 ), where a(02 ) is the oxide ion activity [6]. Not surprisingly, the anodic and cathodic potential limits of carbonate melts are very dependent upon the oxoacidity. Anodic decomposition of the melt is assumed to arise from the oxidation of oxide provided by the thermal decomposition of CO ... 

Thermal decomposition of Co(acac)3 in the absence of oxygen at 100—130°C produces Co(acac)2 in the presence of oxygen stepwise oxidation to Co(OAc)2,xH20 occurs.154... 

The structure of Co(acac)3 is a distorted octahedron, Co—O = 1.888(4) A, Z OCoO = 96.5°.355 Thermal decomposition of Co(acac)3 to Co(acac)2 has been reported, and the mass spectra of Co(acac)2,oxine and Co(acac)(oxine)2 have been studied.356 Acetic acid and [Co(CO)3L2]+ (L = bipy or phen) in alcohol-water react to form [Co(acac)L2]2+ and [Co(acac)2L] +. 357 The cis-trans isomerization of [Co(acac)2(py)X] (X = N3, N02, NCO, or CN) has been examined and the trans - cis rate is N3 > NCO > N02 > CN.358 Potassium cyanate reacts with Co(acac)2 in aqueous solution in the presence of pyridine and hydrogen peroxide to form [Co-(acac)2(NCOXpy)].358 An extension of this work to KNCS produced trans-[Co(acac)2-(SCN)(py)]. On standing this complex undergoes linkage isomerism to the isothio-cyanato analogue, whilst under reflux cis-[Co(acac)2(NCSXpy)] forms.359... 

The ammines of cobalt(II) are much less stable than those of cobalt(III) thermal decomposition of [Co(NH3)6]Cl2 is characterized by reversible loss of ammonia, whereas that of [Co(NH3)6]Cl3 is not. In his classic dichotomy of complexes, Biltz regarded [Co (NH 3)3] Cl 2 as the prototype of the normal complex and [Co(NH3)6]Cl3 as that of the Werner or penetration complex. Hexaamminecobalt-(II) chloride has been prepared by the action of gaseous ammonia on anhydrous cobalt (II) chloride or by displacing water from cobalt(II) chloride 6-hydrate with gaseous ammonia. It may also be synthesized in nonaqueous solvents by passing dry ammonia through solutions of cobalt(II) chloride in ethanol, acetone, or methyl acetate. Syntheses in the presence of water include heating cobalt(II) chloride 6-hydrate in a sealed tube with aqueous ammonia and alcohol and the treatment of aqueous cobalt(II) chloride with aqueous ammonia followed by precipitation of the product with ethanol. The latter method is used in this synthesis. Inasmuch as the compound is readily oxidized by air, especially when wet, the synthesis should be performed in an inert atmosphere. 

Benzoyl cyanide can be prepared by the thermal decomposition of co-isonitrosoacetophenone,2 from silver cyanide and benzoyl chloride,3 from anhydrous hydrogen cyanide and benzoyl chloride in the presence of pyridine/ and by the thermal decomposition of phenylchlo ronitrocyanomethane.5 5... 

Perez-Ramirez, J., Mul, G. and Moulijn, J. A. (2001). In situ Fourier transformed infrared and laser Raman spectroscopic study of the thermal decomposition of Co-AI and Ni-Al hydrotalcites. Vibrational Spectroscopy, 27,75-88. 

The structures of M3Co(CN)g [M3 = K3, CsjLi, or Co(NH3)g] have also been reported. ° Co3[Co(CN)g]2 has been prepared and it is suggested that the compound previously reported as Co(CN)2,xH20 is in fact a contaminated form of this compound. Thermal decomposition of Co(CN)g gives a range of products terminating in Co(CN)2, Co(CN), and finally metallic cobalt. ... 

Another example is the thermal decomposition of [Co(urea)g](NOj)2 compound [16] that suffer upon heating successive transformations melting, configurational change, dimerization, and gradual oxidation of Co + to Co (Scheme 3.3). 

The thermal decomposition of Co-BDC coordination polymer H2BDC = 1,4-ben-zenedicarboxylic acid) leads to hierarchical porous CO3O43D superstructures, assembled from 2D sheets, densely composed of many uniform nanoparticles [119]. Depending on the calcination temperature, 0036 5 or CoO were obtained from [Co(ox)-2.5H20] compound [120]. 

Hdrnig, H., Walther, E. and Schubert, U. (1985) Silicon-containing carbene complexes. 5. (Ethylthio)(triphenylsilyl) ketene by thermal decomposition of (CO)5WC(SEt)SiPh3. Organometallics, 4, 1905-1906. 

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