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  2. Copper cycle - Wikipedia

    en.wikipedia.org/wiki/Copper_cycle

    Copper mining contributes significantly to copper emissions into fresh waters. Copper is also introduced into freshwater during metal corrosion , degradation, and abrasion of copper. Scrap copper metal is commonly recycled, but at the end of its manufacturing life cycle, it is discarded to landfills, which can leach significant copper into ...

  3. Sonogashira coupling - Wikipedia

    en.wikipedia.org/wiki/Sonogashira_coupling

    The copper cycle is not entirely well described. It is suggested that the presence of a base results in the formation of a π-alkyne complex E. This increases the acidity of the terminal proton and leads to the formation of copper acetylide, complex F, upon deprotonation.

  4. Magdeburg hemispheres - Wikipedia

    en.wikipedia.org/wiki/Magdeburg_hemispheres

    The Magdeburg hemispheres are a pair of large copper hemispheres with mating rims that were used in a famous 1654 experiment to demonstrate the power of atmospheric pressure. When the rims were sealed with grease and the air was pumped out, the sphere contained a vacuum and could not be pulled apart by teams of horses. Once the valve was opened ...

  5. Catechol oxidase - Wikipedia

    en.wikipedia.org/wiki/Catechol_oxidase

    The catalytic cycle begins with the catechol oxidase in its native oxidized Cu(II)-Cu(II) state with a coordinated hydroxide ion bridging the two copper centers. As catechol enters the active site , a proton is abstracted from one of the alcohols.

  6. Copper–chlorine cycle - Wikipedia

    en.wikipedia.org/wiki/Copper–chlorine_cycle

    The Cu–Cl cycle is a hybrid process that employs both thermochemical and electrolysis steps. It has a maximum temperature requirement of about 530 degrees Celsius. [1] The Cu–Cl cycle involves four chemical reactions for water splitting, whose net reaction decomposes water into hydrogen and oxygen. All other chemicals are recycled.

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  8. Cross-coupling reaction - Wikipedia

    en.wikipedia.org/wiki/Cross-coupling_reaction

    Many mechanisms exist reflecting the myriad types of cross-couplings, including those that do not require metal catalysts. [7] Often, however, cross-coupling refers to a metal-catalyzed reaction of a nucleophilic partner with an electrophilic partner.

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