Differences in the coordinating ability of water, perchlorate and tetrafluoroborate toward copper(I). The x-ray crystal structures of [Cu(1,4-thioxane)₃OClO₃], [Cu(1,4-thioxane)₃OH₂]BF₄ and [Cu(1,4-thioxane)₄BF₄

Summary

Crystal structure determinations of the non-isomorphous salts, Cu(1,4-thioxane)₃(ClO₄) and Cu(1,4-thioxane)₄(BF₄) were carried out. The former compound was shown to contain strongly coordinated perchlorate while the later contains ionic tetrafluoroborate. For the coordinated perchlorate group, Cu-O is 2.278(8) Å. A third compound, Cu(1,4-thioxane)₃(H₂O)(BF₄), was also characterized by x-ray crystallography, and contains a coordinated water molecule (with Cu-O 2.234(7) Å) that is hydrogen bonded to ionic tetrafluoroborate. All three complexes have approximately tetrahedral geometry. The copper(I) atom is coordinated to the sulfur atoms of the 1,4-thioxane rings. In each of the complexes, one of the 1,4-thioxane six-membered rings is coordinatedvia an equatorial ring position and the remaining two or three rings are coordinatedvia an axial position. The compound, Cu(1,4-thioxane)₄(ClO₄), was also prepared and found to be isomorphous with Cu(1,4-thioxane)₄ (BF₄), enabling a comparison to be made between the i.r. spectra of ionic and coordinated perchlorate in similar complexes.