Cyanide spectroscopy

Legon A 0, Millen D J and Mjdberg P J 1977 The hydrogen cyanide dimer identification and structure from microwave spectroscopy Chem. Phys. Lett. 47 589... 

EPR investigations are necessarily carried out in frozen solution at low temperature. Room temperature binding of thiols to FeMoco has been monitored by F NMR spectroscopy using /J-CF3C6H4S as the reporter ligand. These experiments revealed that the binding of thio-late is characterized by a dynamic equilibrium between the FeMoco and thiolate (159) and that cyanide and methyl isocyanide can bind to isolated FeMoco complexed with thiol (160). 

Goldman, A. et al.. Fiber laser intracavity absorption spectroscopy of ammonia and hydrogen cyanide in low pressure hydrocarbon flames, Chem. Phys. Lett., 423, 147, 2006. 

In 1965 Kwiatek and Seyler 109) reported the existence of a cyanide-dependent equilibrium involving a- and Tr-allyl complexes, revealed by NMR spectroscopy in aqueous solution, viz.. 

The effects of tin/palladium ratio, temperatnre, pressnre, and recycling were studied and correlated with catalyst characterization. The catalysts were characterized by chemisorption titrations, in situ X-Ray Diffraction (XRD), and Electron Spectroscopy for Chemical Analysis (ESCA). Chemisorption studies with hydrogen sulfide show lack of adsorption at higher Sn/Pd ratios. Carbon monoxide chemisorption indicates an increase in adsorption with increasing palladium concentration. One form of palladium is transformed to a new phase at 140°C by measurement of in situ variable temperature XRD. ESCA studies of the catalysts show that the presence of tin concentration increases the surface palladium concentration. ESCA data also indicates that recycled catalysts show no palladium sulfide formation at the surface but palladium cyanide is present. 

As already mentioned, hydrogen cyanide is formed in simulation experiments using reducing primeval atmospheres. CN was discovered in interstellar space as early as 1940 by optical spectroscopy (Breuer, 1974), and later HCN itself (from measurements using millimetre wavelengths). Only a few years after the Miller-Urey experiments, Kotake et al. (1956) obtained HCN in good yields by reacting methane with ammonia over aluminium-silicate contacts ... 

Hipps KW, Mazur U (1980) An inelastic electron tunneling spectroscopy study of some iron cyanide complexes. J Phys Chem 84 3162-3172... 

Blago, R.B. 1989. Indirect determination of free cyanide by atomic absorption spectroscopy. Atom. Spectros. 10 74-76. 

Lotito, S., P. Blondet, A. Francois, M.V. Kienlin, C. Remy, J.P. Albrand, M. Decorps, and A.L. Benabid. 1989. Correlation between intracellular pH and lactate levels in the rat brain during cyanide induced metabolism blockade a combined 31P- H in vivo nuclear magnetic spectroscopy study. Neurosci. Lett. 97 91-96. 

Irrespective of the detailed interpretation of these results (25), they provide further evidence against the oft-popular notion that SERS for cyanide and other strongly coordinating adsorbates arises from specific "surface complexes" [such as Au(CN) ] (28) as distinct from the preponderant adsorbate species presumably sensed by infrared spectroscopy (also see reference 7). 

Azolium systems with C-H bonds can be deprotonated to give rise to an internal azolium ylide or an isoelectronic stable azole carbene system, whereas fully substituted heterocycles such as 142 can evolve in a more complex manner under basic conditions or with nucleophiles. Thus, in the presence of cyanide ion, the formation of adduct 143 could be evidenced by NMR spectroscopy. This intermediate, when stirred at ambient temperature for 48 h in the presence of dimethylacetylene azodicarboxylate (DMAD), led to the adduct 146 (28%) along with products 148 (40%) and 149 (12%) (Scheme 14) <1997JP12919>. 

AgN03 = silver nitrate CICN = cyanogen chloride CN" = cyanide ion CNATC = cyanides not amenable to chlorination (Rosentreter and Skogerboe 1992) AAS = atomic absorption spectroscopy EPA = Environmental Protection Agency FIA = flow injection analysis GC/ECD = gas chromatograph/electron capture detector HCN = hydrogen cyanide NaOH = sodium hydroxide NIOSH = National Institute for Occupational Safety and Health... 

By 1949 low temperature spectroscopy had been introduced. With this technique Keilin and Hartree detected a further component in the electron transfer chain which had a sharp band at 552 nm. They later showed it to be identical with cytochrome cj, which had first been observed by Yakushiji and Okunuki (1940) during succinate oxidation by cyanide-inhibited beef heart muscle. As the oxidation of cytochrome C was accelerated by cytochrome c, Okunuki and Yakushiji (1941) had placed C] in the chain in the order... 

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