Copper spectroscopy

In the 1970s, 2,3-QD from Aspergillus flavus was purified and was shown to be a 112-kDa type 2 (ie, normal copper, spectroscopy similar to copper(II)(aq)) copper glycoprotein (89). The 2,3-QD isolated iiom. Aspergillus niger is a 148-kDa glycoprotein, and its EPR spectrum showed it is also a typical type 2 copper... 

After in situ neutralisation, the complexation behaviour of 4.44 was studied using UV-vis spectroscopy. The absorption maximum of this compound shifted from 294 nm in pure water to 310 nm in a 10 mM solution of copper(II)nitrate in water. Apparently, 4.44, in contrast to 4.42, does coordinate to copper(II)nitrate in water. 

Most importantly, analysis using UV-spectroscopy also demonstrated that, as anticipated, the elimination reaction of 4.51 is less efficient than that of 4.44. Ag in, addition of copper(II)nitrate significantly suppresses this reaction. 

M HNO3. The concentration of Cu and Zn in the diluted supernatant is determined by atomic absorption spectroscopy using an air-acetylene flame and external standards. Copper is analyzed at a wavelength of 324.8 nm with a slit width of 0.5 nm, and zinc is analyzed at 213.9 nm with a slit width of 1.0 nm. Background correction is used for zinc. Results are reported as micrograms of Cu or Zn per gram of FFDT. 

Whereas ATR spectroscopy is most commonly applied in obtaining infrared absorption spectra of opaque materials, reflection-absorption infrared spectroscopy (RAIRS) is usually used to obtain the absorption spectrum of a thin layer of material adsorbed on an opaque metal surface. An example would be carbon monoxide adsorbed on copper. The metal surface may be either in the form of a film or, of greaf imporfance in fhe sfudy of cafalysfs, one of fhe parficular crysfal faces of fhe mefal. 

One other very important attribute of photoemitted electrons is the dependence of their kinetic energy on chemical environment of the atom from which they originate. This feature of the photoemission process is called the chemical shift of and is the basis for chemical information about the sample. In fact, this feature of the xps experiment, first observed by Siegbahn in 1958 for a copper oxide ovedayer on a copper surface, led to his original nomenclature for this technique of electron spectroscopy for chemical analysis or esca. 

Colorimetric procedures are often used to determine copper in trace amounts. Extraction of copper using diethyldithiocarbamate can be quite selective (60,62), but the method using dithhone is preferred because of its greater sensitivity and selectivity (50—52). Atomic absorption spectroscopy, atomic emission spectroscopy, x-ray fluorescence, and polargraphy are specific and sensitive methods for the deterrnination of trace level copper. 

Internal surfaces were covered with a tan deposit layer up to 0.033 in. (0.084 cm) thick. The deposits were analyzed by energy-dispersive spectroscopy and were found to contain 24% calcium, 17% silicon, 16% zinc, 11% phosphorus, 7% magnesium, 2% each sodium, iron, and sulfur, 1% manganese, and 18% carbonate by weight. The porous corrosion product shown in Fig. 13.11B contained 93% copper, 3% zinc, 3% tin, and 1% iron. Traces of sulfur and aluminum were also found. Near external surfaces, up to 27% of the corrosion product was sulfur. 

Removal of deposits and corrosion products from internal surfaces revealed irregular metal loss. Additionally, surfaces in wasted areas showed patches of elemental copper (later confirmed by energy-dispersive spectroscopy) (Fig. 13.12). These denickelified areas were confined to regions showing metal loss. Microscopic analysis confirmed that dealloying, not just redeposition of copper onto the cupronickel from the acid bath used during deposit removal, had occurred. 

A number of ferrites have been subjected to shock modification and studied with x-ray diffraction as well as static magnetization and Mossbauer spectroscopy [87V01], Studies were carried out on cobalt, nickel, and copper ferrites as well as magnetite (iron ferrite). 

Recently, other authors when studying the activation of hydrogen by nickel and nickel-copper catalysts in the hydrogen-deuterium exchange reaction concentrated for example only on the role of nickel in these alloys (56) or on a correlation between the true nickel concentration in the surface layer of an alloy, as stated by the Auger electron spectroscopy, and the catalytic activity (57). 

Bioinorganic applications of m.c.d. spectroscopy copper, rare earth ions, cobalt and non-heme iron systems. D. M. Dooley and J. H. Dawson, Coord. Chem. Rev., 1984, 60,1 (176). 

Blue copper electron transfer proteins, 6,712-717 Blue copper oxidases, 6,699 Blue copper proteins, 2, 557 6, 649 Blue electron transfer proteins, 6,649,652 spectroscopy, 6, 651 Blue oxidases copper, 6,654,655 Blueprint process, 6,124 Blue proteins model studies, 6,653 Boleite... 

Complexes. The structure of an n a charge-transfer complex between quinoxaline and two iodine atoms has been obtained by X-ray analysis and its thermal stability compared with those of related complexes. The hydrogen bond complex between quinoxaline and phenol has been studied by infrared spectroscopy and compared with many similar complexes. Adducts of quinoxaline with uranium salts and with a variety of copper(II) alkano-ates have been prepared, characterized, and studied with respect to IR spectra or magnetic properties, respectively. 

Another study (200) presented IR data for a number of hydride and deuteride species. Using matrix-isolation spectroscopy in conjunction with a hollow-cathode, sputtering source (the apparatus for which is shown in Fig. 36), the IR-active vibrations of the diatomic hydrides and deuterides of aluminum, copper, and nickel were observed. The vibra-... 

The copper atom-acetylene matrix-reaction, monitored originally by esr spectroscopy (60) has now been investigated by IR/UV-visible spectroscopy (144), and there is general agreement on the identification of two mononuclear species, CuCCaHali.. The esr/IR/UV-visible... 

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