Univalent Metal Complexes of (Perfluorophenoxy)acetic Acid. The Crystal Structures of (2,3,4,5,6-Pentafluorophenoxy)acetic Acid, Bis-μ-[(2,3,4,5,6-pentafluorophenoxy)acetato-O,O']-bissilver(I) and catena-Bis-μ-[(2,3,4,5,6-Pentafluorophenoxy)acetato-O]-bismercury(I)

Abstract

The crystal structures of perfluorophenoxyacetic acid [(2,3,4,5,6- pentafluorophenoxy )acetic acid] and its anhydrous complexes with silver(I) and mercury(I) have been determined by X-ray diffraction and refined to residuals R = 0.046, 0.042 and 0.104 for 1235, 1789 and 2750 observed reflections respectively. The acid forms the usual hydrogen- bonded cyclic dimers [O---O, 2.705(3)Ǻ] with the oxyacetic acid side- chain synclinally oriented. Crystals age triclinic, space group Pī with Z 2 in a cell of dimensions a 7.479(1), b 7.592(2), c 8.463(2)Ǻ,α 80.15(2),β 85.34(2),γ 61.31(1)Ǻ. The silver complex, [Ag2L2],(1), has crystals with a 5.992(3), b 30.22(2), c 5.277(2)Ǻ, β 106.42(5)°, space group P21/a and Z 2. The bis-carboxylato (O,O′) dimers have Ag-Ag 2.943(1)Ǻ with Ag-O, 2.203, 2.230(3)Ǻ and O-Ag-O 161.6(2)°. The complex with mercury(I), [Hg2L2]n, (2), is centrosymmetric with the usual linear O-Hg-Hg-O-bonds [Hg-Hg, 2.514(1)Ǻ; Hg-O, 2.13(1)Ǻ; O-Hg-Hg, 173.9(2)°]. Longer peripheral bonds to Hg [Hg-O, 2.63(1)Ǻ] produce a polymeric structure. Crystals of (2) are triclinic, space group Pī with Z 1 in a cell of dimensions a 5.038(1), b 5.970(1), c 15.774(6)Ǻ, α 80.77(2),β 86.42(2),γ 84.38(2)°.

Preparation and Comprehensive Characterization of [Hg6(Alanine)4(NO3)4]·H2O

“…Hg−Hg−O (carboxylate) bond angles range from 158.4° to 174.1°. This near-linearity of the Hg−Hg−O moiety is present in the few other reported mercury(I)−carboxylate structures (166.6−177.9°; Table ). – A close contact (3.0552(9) Å) between two mercury(I) atoms is responsible for the association of adjacent mercury(I) dimers (between Hg1 and Hg5 in Figure , cf. sum of the covalent radii, 2.54 Å; sum of the van der Waals radii, 4.1 Å).…”