THE CRYSTAL-STRUCTURE OF BIS(2,2'-BIPYRIDINE)-CATENA-MU-TETRAFLUOROBORATO-COPPER(II) TETRAFLUOROBORATE

The crystal structure of the title compound was determined by means of the X-ray diffraction technique. The crystal is triclinic, space group P1 OVER BAR , a equals 11. 288(8), b equals 15. 186(17), c equals 7. 368(4) A, alpha equals 74. 93(3), beta equals 78. 23(3), gamma equals 65. 92(3) degree , and Z equals 2. The structure was solved by the heavy-atom method and refined by the least-squares method to R equals 0. 068 for 3678 non-zero reflections. The crystal is composed of BF//4** minus ions and polymeric chains of left bracket Cu(BF//4)(bpy)//2** plus right bracket in which a tetrafluoroborate ion bridges two adjacent copper atoms through its two fluorine atoms. The coordination polyhedron around the copper atom is a tetragonally distorted octahedron; the four nitrogen atoms of bipyridine molecules in the equatorial plane are arranged in a flattened tetrahedral manner (average Cu-N equals 1. 99 A) and the two axial Cu-F distances are 2. 566(6) and 2. 662(4) A.