Cu2+ cations

We now consider a slightly different cell in which the copper half-cell is the positive pole. Perhaps the negative electrode is zinc metal in contact with Zn2+ ions. If the cell discharges spontaneously, then the electron-transfer reaction is the reduction reaction in Equation (7.7) as depicted in the strip cartoon in Figure 7.8. A bond forms between the surface of the copper electrode and a Cu2+ cation in the solution The electrons needed to reduce the cation come from the electrode, imparting a net positive charge to its surface. 

Redox is a term that stands for reduction and oxidation. Reduction is the gain of electrons and oxidation is the loss of electrons. In these reactions, the number of electrons gained must be identical to the number of electrons lost. For example, suppose a piece of zinc metal is placed in a solution containing the Cu2+ cation. Very quickly, a reddish solid forms on the surface of the zinc metal. That substance is copper metal. At the molecular level, the zinc metal is losing electrons to form the Zn2+ cation and the Cu2+ ion is gaining electrons to form copper metal. We can represent these two processes as ... 

Elements on this activity series can displace ions of metals lower than themselves on the list. If, for example, one placed a piece of tin metal into a solution containing Cu(N03)2(aq), the Sn would replace the Cu2+ cation ... 

When an equimolar mixture of Ni2+, Cu2+ and Zn2+ was added to aqueous electrochemical solutions of [29] and [30] the ferrocene-ferrocenium redox couple shifted anodically by an amount approximately the same as that induced by the Cu2+ cation alone. This result suggests that [29] and [30] are... 

Cu-A1MCM-41 samples, activated as above, possess Cu2 , Cu , and Cu2 0 species Cu2 cations are easier reduced if NbMCM-41 matrix is applied. 

Figure 3.11 Orgel diagram for transition metal ions possessing rD spectroscopic terms in octahedral crystal fields of increasing intensity. The right-hand side applies to 3d1 (e.g., Ti3+) and 3d6 (e.g., Fe2+) cations and the left-hand side to 3d4 (e.g., Mn3+) and 3d9 (e.g., Cu2+) cations in octahedral coordination. The diagram in reverse also applies to the cations in tetrahedral, cubic and dodecahedral coordinations.

In the specific case of calixarenes, there are very few studies related to metal-mediated self-assembly into cage molecules. Early examples reported by Shinkai and coworkers include bis(acac)-calix[4]arene dimer (1) held together by Cu2+ cations... 

Room-Temperature Lattice Parameters for Several Spinels Containing Mn3+ and/or Cu2+ Cations... 

Kucherov et al.[9] have shown that at low Cu levels, all of the Cu exchanged into the zeolite is detected as isolated Cu2+ cations existing in two different coordination states four coordinate square planar and five coordinate square pyramidal. Figure 2 shows a typical spectrum of Cu2 + exchanged MFI, showing the two different Cu2+ species.[10]. Both species are located in the main channels of the MFI structure [9]. 

Fig. 4. Structure and coordination of the Cu2+ cation located on top of the six-member ring on the zeolite channel wall. Geometries optimized with various models.

Noguera, M., Bertran, J., 8c Sodupe, M. (2008). Cu2+/+ cation coordination to adenine-thymine base pair. Effects on intermolecular proton-transfer processes. The Journal of Physical Chemistry B, 112, 4817. 

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