Inorganic-organic composites from solvothermal routes:: Extended structures of [CuX(pyrazine)]∞ (X=CN, Cl, CF3CO2), and Cu(NO2)2(pyz)

Several attempts were made to generate organic-separated copper oxide layers via solvothermal routes. Four new extended solids were isolated from the reaction of copper complexes with pyrazine in superheated solvents. Decomposition of copper(II) hexafluoroacetylacetonate (hfacac) in the presence of pyrazine(pyz) at 195 degrees C in THF/H2O (14/1 v/v) yields primarily Cu (CF3CO2)(pyz) (1). Alternatively, 1 can be formed from solvothermal treatment of [Cu (hfacac)(2)](2)(pyz) at 195 degrees C in MeOH/H2O (14/1 v/v). Reaction of CuO with pyz and NH4Cl 'mineralizer' cleanly forms CuCl(pyz) (2), while the presence of HNO3 as a mineralizer promotes the formation of a mixture of products including CuCN(pyz) (3) and Cu(NO2)(2)(pyz) (4). The three CuX(pyz) phases each have unique structure types. Phases 1 and 3 have three-dimensional lattices, while 2 has a two-dimensional layered structure. The new Cu(II) phase (4) is structurally similar to the known orthorhombic phase, Cu(NO3)(2)(pyz), but 4 crystallizes in a monoclinic space group. (C) 1999 Elsevier Science Ltd. All rights reserved.