PREPARATION, STRUCTURE, AND PROPERTIES OF TETRAMETHYLAMMONIUM SALT OF MU4-OXO-HEXA-MU-CHLORO-TETRA(CHLOROCUPRATE(2))

The preparation, structure, and properties of a polynuclear copper(II) compound, [(CH3)4N)4[Cu4OCl,10], are reported. The compound crystallizes as red, cubic crystals (a = 19.30 ± 0.02 Å) of space group P43n with eight formula units per unit cell; the calculated denshy of 1.70 g/cm3 agrees well with the experimental value of 1.69 ± 0.02 g/cm3. A total of 310 unique, nonzero reflections were visually estimated from precession camera photographs; least-squares refinement resulted in a conventional R value of 9.0%. The polynuclear anion contains a central oxide ion coordinated tetrahedrally to four copper(II) ions; the copper(II) ions are bridged in pairs by six chloride ions. The remaining four chloride ions complete a trigonal-bipyramidal coordination sphere around each copper(II) ion. Although there are two crystallographically independent anions, the two are virtually identical and undistorted. Average bond distances and angles are: Cu-O, 1.93 ± 0.01 Å; Cu-Clax, 2.21 ± 0.04 Å; Cu-Cleq, 2.41 ± 0.02 Å; Cleq-Cu-Cleq, 119 ± 0°; 0-Cu-Clax, 179 ± 1°. © 1969, American Chemical Society. All rights reserved.