Compounds Cu(I).

These compounds can be prepared by Cu(II) reduction. Cu₂О is formed at the action of hydrazine, hydroxylamine, aldehydes, glucose on Cu(ОH)₂:.

4Cu(ОH)₂ + N₂H₄ = 2Cu₂O + N₂ + 6H₂O

or 4CuO 2Cu₂O + О₂

2CuI +2NaOH = Cu₂O + H₂O + 2NaI

CuOН does not exist. It decomposes immediately at the moment of liberation on Cu₂O and H₂O. Cu₂O has predominately basic properties. It react with acids::

Cu₂O + 4HCl = 2H[CuCl₂] + H₂O

Cu₂O + H₂SO₄ = Cu + CuSO₄ + H₂O.

Salts Cu(І) can be obtained by Cu(II) reduction:

2CuSO₄ + 2NaCl + SO₂ + 2H₂O = 2CuCl¯ + Na₂SO₄ + 2H₂SO₄

CuCl₂ + 2HCl + Cu = 2H[CuCl₂] (+H₂O) = 2HCl + 2CuCl¯

CuI formation is a result of redox process that proceeds quantitavely:

2CuSO₄ + 4KI = 2CuI¯ + I₂ + 2K₂SO₄

Salts Cu(I) are colourless that are usually insoluble in water but at the action of ammonia and some other ligands can form soluble complexes:

CuCl + 2NH₃ = [Cu(NH₃)₂]Cl

CuCl + HCl = H[CuCl₂]

Complexes of Cu(I) with monodental ligands with coordination number 2 have maximal stability (for instance, [Cu(NH₃)₂]⁺, [CuCl₂]^-, [Cu(СN)₂]^-) and have linear configuration (Cl-Cu-Cl)^-. Complexes with coordination number 4 are tetrahedral. Some complexes are oxidized by oxygen:

4[Cu(NH₃)₂]⁺ + 4NH₃ + 4NH₄⁺ + O₂ = 4[Cu(NH₃)₄]²⁺ + H₂O

This reaction is used to absorb oxygen from gaseous mixtures.

In general, equilibrium 2Cu⁺ Cu²⁺ + Cu is easily displaced depending on conditions. The presence of I^-, CN^- that form stable compounds with Cu(I) displaces equilibrium to Cu⁺ formation. The presence of SO₄^2-, ClO₄^- shows the contrary action.

Compounds Cu(III). These compounds are obtained by oxidation of Cu(II). The deep red Cu₂О₃ forms at the action of Na₂O₂ or K₂S₂O₈ on Cu(ОН)₂ or Na₂[Cu(ОH)₄]:

2Na₂[Cu(ОH)₄] + Na₂O₂ = Cu₂О₃ + 6NaOH + H₂O

Potassium superoxide being smelted with CuO gives potassium cuprate (III):

2KO₂ + 2CuO = 2KCuO₂ + O₂

This crystalline substance is blue or deep blue. It is completely decomposed by water. Compounds of Cu(III) are unstable and behave as very strong oxidising agents:

2Cu₂О₃ + 4H₂SO₄ = 4CuSO₄ + O₂ + 4H₂O.

Дата добавления: 2015-07-25