Synthesis and anion exchange reactions of a layered copper-zinc hydroxy double salt, Cu1.6Zn0.4(OH)3(OAc)·H2O

Abstract

A mixed-metal hydroxysalt of formula Cu 1⋅6 Zn 0⋅4 (OH) 3 (OAc)⋅H 2 O has been synthesized by an acetate hydrolysis route. Acetate ions can be exchanged with simple inorganic anions such as chloride and nitrate, and organic anions such as benzoate and large surfactant anions such as dodecyl sulphate. Structures of these hydroxysalts are derived from that of Cu 2 (OH) 3 NO 3 ⋅H 2 O with some of the Cu 2+ ions being replaced by Zn 2+ .

Simple route for the synthesis of copper hydroxy salts

“…Generally, hydroxy salts are synthesized by one of the following methods: the pyrolysis of a metallic salt; 4 the reaction of a metallic oxide with the corresponding aqueous solution of a salt of the desired metal; 3-5 the slow precipitation of HS with sodium hydroxide from a metal salt solution; 4,8,11 the co-precipitation procedure employed for LDH synthesis, introduced by Newman and Jones. 4 Additionally, the reaction of a metal oxide (MeO) with zinc acetate in an aqueous media, was reported by Morioka et al 2 Some of these procedures demand strict control of experimental variables, especially pH, temperature and concentration of the reactants to avoid the formation of sub-products like Cu(OH) 2 and CuO.…”

“…The strong bands centered at 3696 cm -1 and 3440 cm -1 were assigned to the stretching modes of OH -groups, present in the layered structure and in the water molecules present in the interlamellar space. 11 The peaks observed in the low frequency region were attributed to vibrational modes involving the Mg-OH bonds. 6 The peaks located at 1426 and 1483 cm -1 are consistent with those found by Frost and Kloprogge, 6 which show the presence of magnesite (MgCO 3 ), an impurity produced most likely through contamination with CO 2 from the environment.…”

“…The narrow band at 3544 cm -1 corresponds to free OH groups, while the one centered at 3427 cm -1 indicates the presence of hydrogen bonded OH groups. 11,22 The peaks at 1045 (ν 1 ), 800 (ν 2 ), 1343, 1375 and 1426 cm -1 (ν 3 ) can be assigned to vibrational modes of nitrate (NO 3 -) ions, 25 whose interaction with cooper hydroxide layers is evidenced by the appearance of symmetric and asymmetric stretching modes of NO 3 -at 1426 and 1343 cm -1 . The band at 1045 cm -1 corresponds to the N-O stretching vibration of a monodentate O-NO group, which is active in both, FT-IR and Raman spectra (see Figure 4), in good agreement with the literature.…”

“…The stacking of such a sheets in the z direction lead to the formation of a neutral threedimensional structure. 4,11 However, the nitrate ions can be displaced by others negative charged molecules.…”

Spectroscopy of selected copper group minerals: ktenasite, orthoserpierite and kipushite

“…ions by Zn 2? ions [17]. The NIR and IR spectroscopy is a useful study of the behaviour of substitutional effects of Zn 2?…”