A Copper Mirror

In ancient times copper was known even before iron. In the book Dic Schulc cler Chemie (The School of Chemistry) published in 1881 Julius Adolph Stockhardt writes on copper as follows  

Copper was derived in antiquity primarily from the Island ttj (Cyprus, where copper ore was to be found in abundance this accounts for the name cuprum or Cyprian rneial. When it. was later regarded a good idea to confer mythological names on the metals, copper was identified with the patron goddess oj Cyprus, Venus, as well as with her symbol. Copper possesses numerous outstanding characteristics, which have transformed it into an exceptionally useful metal namely  

Although copper possesses no odor, it does conjer upon sweaty hands and water in which it has stood for a long time (as in copper alembics or kettles) a peculiar, unpleasant odor. 

Hydrazine hydraie solutions are extremely toxic. The experiment must be car ried out in the well ventilated hood safety glasses and protective gloves inusi be worn. 

1 mol/L copper(II) acetate solution, ca. 80% hydrazine hydrate solution. Experimental Procedure 

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If the product is heated to 130° or higher, decomposition of product occurs with the formation of a copper mirror. 

There are several examples of the concerted mechanism. However, no report of an insertion of a carbon—carbon triple bond into a metallacyclopentadiene had appeared prior to discovery of this reaction. At low temperatures, during the reaction of zirconacyclopentadienes with DMAD, the formation of trienes (79) is observed upon hydrolysis. This clearly indicates that the benzene formation involves the insertion (addition) reaction of DMAD. As shown in Eq. 2.50, the alkenyl copper moiety adds to the carbon—carbon triple bond of DMAD and elimination of Cu metal leads to the benzene derivatives 72. Indeed, a copper mirror is observed on the wall of the reaction vessel. 

The Cu(2p3/2) photoelectron and LW Auger spectra obtained from a copper mirror treated with an aqueous solution of y-APS at pH 10.4 are shown in Fig. 13. Two components were observed near 932.4 and 934.9 eV in the Cu(2p3/2) photoelectron spectrum, clearly indicating the presence of Cu(I) and Cu(II), respectively. The presence of Cu(II) was confirmed by a broad, weak shake-up satellite near 944.0 eV. 

Three different crystallographic modifications of the anhydrous salt can be prepared. The decompositions of these reactants (430 to 506 K) exhibit sigmoid a-time curves which have been attributed [11] to a chain-type process through the formation of the volatile and unstable copper(I) salt as intermediate. This was indicated by the formation of a copper mirror on the containing vessel. Schuffenecker et al. [11] identified the rate limiting step as electron transfer. Erofeev et al. [10,12] showed that the kinetic behaviours of two forms of the salt were different. This was ascribed to variations in the dispositions of copper ions in the crystal structures of the reactants. 

When the reaction of zirconacyclopentadiene 4 with DMAD proceeded in the presence of CuCl at -78 °C, the linear triene 20 was obtained in 78% yield after hydrolysis. When this mixture was wanned to room temperature, benzene derivative 6 was formed as a single product. This clearly indicates that benzene formation involves the insertion reaction of the third alkyne (DMAD) into the metal-carbon bond (path B). As shown in Scheme 11.7, the alkenyl copper moiety added to the carbon-carbon triple bond of DMAD and elimination of Cu metal led to the benzene derivatives 6. Indeed, a copper mirror was observed on the wall of the reaction vessel. However, benzene derivatives were also obtained by using only a catalytic amount of CuCl. In this case, copper metal deposition was obviously not observed. This means that path A cannot be ruled out. 

The activators typically used in fluxes are corrosive. A flux can corrode the solder joint, copper traces and circuitry both before reflow and post reflow. That is, corrosion can occur during the assembly process subsequent to solder paste deposition, while the work is being processed through the assembly line. In addition, corrosion may result from the activators that remain on the board post reflow. A copper mirror test is used to determine the corrosive effect of the flux on a copper film deposited on a glass slide. The ability to classify flux activity levels helps to determine... 

SiO or SiS are generated when O2 or H2S are passed over heated Si at about 1500 K in an AI2O3 furnace. The high temperature gases are condensed on a helium cooled copper mirror together with an excess of argon. 

Figure 11 shows the reflection spectra of bare copper mirrors heated at high temperatures for 15 min. A 330 C, cuprous oxide was detected by the band absorbed at 655 cm . However, at 3 0 and k00 C, two bands were observed near 6l1 and 655 cm ... 

Figure 12 shows the results of PVI(1) after being heated at various high temperatures for 15 min. The bands of cuprous oxides formed on bare copper mirrors at corresponding temperatures are superimposed on the PVI(1) spectra for direct comparisons. The scale of the two types of spectra is shown by the difference between the maximum and minimum absorbance, A. Note that no... 

A solulion of CuCl in HCI absorbs carbon monoxide, forming copperil) carbonyl chloride. Cu(CO)Cl H 0. This reaction, which is used In gas analysis, is Indicative of the ability of copper to combine with carbon monoxide. Evidence for a true carbonyl is limited to the observation that if hot carbon monoxide is passed over hot copper, a metallic mirror is produced in the hotter parts of the tube. Other organometallic compounds include Ihe very unstable methyl copper, CHiCu. phenyl copper. C<,H5Cu, and bixchlurucopper acetylene CjHrtCuCIi . 

The STG was cast from alx 10 3 M solution into which the mirror had been immersed for from 10 to 20 min (see Appendix 1). The presence of a monolayer was confirmed by ellipsometry (18 A). The spectral data agreed with data gathered on a similar system in a powder form. In this case, CuzO powder was immersed in a 0.01 M solution of isooctyl thioglycolate (OTG) in isopropanol for from 1 to 10 min, washed with pure isopropanol, dried in air, and analyzed via infrared transmission in a KBr dispersion pellet (see Appendix 2). A similar spectral shift of approximately 15 cm 1 (1739— 1724 cm-1) was observed and the lack of two distinct carbonyl absorbances suggested the formation of a monolayer. In both cases, the formation of a copper-mercaptoester salt may be responsible... 

Fundamental studies by reflection angle infrared spectroscopy of the bonding of EME coupling agents to metal oxides reveal a significant shift in the carbonyl absorbance band when the coupling agent is applied as a very thin layer on a metal oxide. The shift is reproducible and the extent varies with the type of oxide. These results were obtained both by use of copper mirrors and from CuzO powder coated with very thin layers of model compounds. The compounds were not removable by isopropanol, a solvent for the bulk compound. The thiol absorbances of thin layers of model compounds were also found to decrease in relative intensity with time. This illustrates that a specific chemical interaction has occurred. 

A 2 cm length of isopropanol-washed copper wire was vapor-deposited onto 1 X 3 sections of silicon wafer at a pressure of about 10 5 Torr. The composition of the copper films was determined via XPS to be 99% cuprous oxide. The mirrors were then stored in a desiccator for up to 1 month without any change in composition. Next, a 0.01 M solution of stearyl thioglycolate in isopropanol was prepared. A single, isopropanol-rinsed copper mirror was then immersed into 200 ml of the stearyl thioglycolate solution for 10 min. The mirror was then removed from the solution, air-dried horizontally, and finally immersed into a swirling bath of pure isopropanol for about 30 s. After being air-dried, experimental analysis was then conducted on the prepared films. 

As has been mentioned in 1, smooth surfaces of copper, including those deposited electrolytically, reduced copper mirrors, and polished surfaces were quite inactive (a, i) a minute trace of activity only was occasionally detected in commercial copper gauze, but copper prepared by thermal decomposition of either cupric or cuprous oxides, or copper salts of mono- and dibasic fatty acids, by condensation on china-clay rods2 from the vapour (in nitrogen, to prevent oxidation), or by stirring up the atoms of copper into open formation by heating in ammonia at 820°, was active (t). 

Figure 9. The dependence of the degrees of reflection on the wavelength of visible light for a) the ideal reflectance of copper ( ) and the total reflections of the copper surface polished mechanically (o), the copper surface polished both mechanically and electrochemically (A), b) mirror (+) and diffuse (x) reflections of the copper surface polished mechanically mirror ( ) and diffuse (-) reflections of the copper surface polished both mechanically and electrochemically. (Reprinted from Ref.

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