Systemic syntheses of [Hg{M(CO)4}2]2-, [Hg{M(CO)4}]x (M = Fe, Ru, Os), and structures of [Hg{M(CO)4}2]2- (M = Ru, Os)

The [Hg{M(CO)(4)}(2)](2-) (M = Fe, Ru, Os) anions were prepared by the reaction of K2M(CO)(4) (M = Fe, Ru, Os) with HgCl2 in a 2:1 molar ratio in THF in high yields. The complexes, K-2[Hg{M(CO)(4)}(2)] (M = Ru, Os) are thermally stable. K-2[Hg{Ru(CO)(4)}(2)] decomposes at ca. 170 degrees C, while K-2[Hg{Os(CO)(4)}(2)] decomposes at ca. 220 degrees C. The structures of [PPN](2)[Hg{Ru(CO)(4)}(2)] and [Ph3MeP](2)[Hg{Os(CO)(4)}(2)] were determined from single crystal X-ray diffraction analyses. The anions [Hg{M(CO)(4)}(2)](2-) (M = Ru, Os), are isostructural with [Hg{Fe(CO)(4)}(2)](2-). These consist of two M(CO), units, trigonal-bipyramidal fragments, joined at apical sites by a mercury atom in a linear M-Hg-M array with a staggered arrangement of the three equatorial CO's of the M(CO)(4) units. Crystal data for [PPN](2)[Hg{Ru(CO)(4)}(2)]. 2CH(3)CN: space group P (1) over bar, a = 12.615(2), b = 13.374(2), c = 13.822(2) Angstrom, alpha = 104.97(1), beta = 106.18(1), gamma = 108.92(1)degrees, V = 1956.4(6) Angstrom(3), Z = 1, mol. wt. = 1786.15, rho = 1.481 g cm(-3), mu = 24.6 cm(-1) for Mo-K-alpha radiation. R-f = 0.022, P (1) over bar = 0.028 for 5261 independent reflections with I greater than or equal to 3 sigma(I). Crystal data for [Ph3MeP](2)[Hg{Os(CO)(4)}(2)]: space group P (1) over bar, a = 11.437(2), b = 13.532(2), c = 14.698(2) Angstrom, alpha = 83.98(2), beta = 83.88(2), gamma = 78.41(2)degrees, V = 2207.5(6) Angstrom(3), Z = 2, mol. wt. = 1359.68, rho = 2.046 g cm(-3), mu = 93.35 cm(-1) for Mo-K-alpha radiation. R-f = 0.0327, R-wR2 = 0.0832 for 5375 independent reflections with I greater than or equal to 3 sigma(I). When a 1:1 molar ratio of Na-2[M(CO)(4)] (M = Fe, Ru, Os) and HgCl2 was employed the polymeric complexes [Hg{M(CO)(4)}](x) were obtained. The polymers are stable in air, but they are not soluble in common organic solvents and in water. (C) 1998 Elsevier Science S.A. All rights reserved.