The molecular structures of 2,2'-bipyridyltetrafluorosilicon(IV), SiFeCloHsNa, 2,2'-bipyridyltetrafluorogermanium(IV), GeFaClaH&p, and 2,2'-bipyridyltetrafluorotin(IV), SnF4CloHsNz, have been determined by single-crystal X-ray diffraction. The compounds were crystallized from nitromethane, and in the case of the germanium and tin complexes, two modifications of each were obtained:The unit cell constants are as follows: for SiF&HsNz, space group P21/c (no. 14), 2 = 4, a = 7.195 (2), b = 9.185 ( 2 ) , c = 16.821 (5) A, fi =, 106.85 (2)"; foi GeF4CIoHJTz.CH3N02, space group P21/m (no. l l ) , 2 = 2, a = 11.958 (3), b = 6.924 (2), c = 8.317 (2) A , p = , 96.16 (2)'; for S~F~C~O H & . C H~T~O~, space group P21/c (no. 14), 2 = 4, a = 8.844 (2), b = 11.646 (4), c = 13.420 (5) A , p = 94.04 (2)'. The stable forms of the germanium and tin complexes are possibly disordered, either in space group P62 (no. 171) or space group P64 (no. 172), where a = 11.631 (3), b = 20.319 ( 5 ) A and a = 12.06 (3), b = 20.56 (5) A, respectively; the crystal structures remain unsolved. All three compounds are monomeric, the solvent is not coordinated, and the coordination is the expected distorted cis octahedral.an unsolvated form and a monosolvated form, unstable t o loss of solvent on air-drying.