FAC-DIPYRIDINIOMETHANE AND MER-DIPYRIDINIOMETHANE TRICHLOROTRIFLUOROOSMATE(IV), FAC-[(C5H5N)(2)CH2][OSCL3F3] AND MER-[(C5H5N)(2)CH2][OSCL3F3]

The structures of fac-N,N'-methylenedipyridinium trichlorotrifluoroosm ate(IV), (I), and mer-N,N'-methylenedipyridinium trichlorotrifluoroosm ate(IV), (II), fac- and mer-[(C5H5N)(2)CH2][OsCl3F3], have been determ ined by single-crystal X-ray diffraction at room temperature. The comp lex anions are completely ordered. The Os-F distances in (I) are equal to within 3 e.s.d.'s, as are the Os-Cl distances. The mean Os-F dista nce of 1.948 Angstrom and Os-Cl distance of 2.3199 Angstrom are typica l for bonds altered in length by the trans influence. The asymmetric C l-Os-F coordination axis in (II) has longer Os-F distance [1.976 (3) A ngstrom] and a shorter Os-Cl distance [2.2782 (13)Angstrom] than the s ymmetric F-Os-F and Cl-Os-Cl axes, which have mean bond lengths of 1.9 44 and 2.307 Angstrom, respectively.