Second-sphere coordination in anion binding: sodium hexaamminecobalt(III) tetrakis(4-fluorobenzoate) monohydrate

Abstract

In sodium hexaamminecobalt(III) tetrakis(4-fluorobenzoate) monohydrate, Na[Co(NH3)6](C7H4FO2)4.H2O, determined at 180 K, [Co(NH3)6]3+ cations lie on centres of inversion and form layers in which their C4 axes lie perpendicular to the layer planes. 4-Fluorobenzoate anions lie on twofold axes and general positions and adopt near-planar geometries. Na+ cations and water molecules lie on twofold axes, forming [NaO5] square pyramids that lie between the [Co(NH3)6]3+ cations. The second-sphere interactions between [Co(NH3)6]3+ cations and 4-fluorobenzoate anions comprise edge-to-face and vertex-to-face arrangements. The structure is closely comparable with that of the benzoic acid salt, demonstrating that fluorination of the anion in the para position has no significant influence on the second-sphere interactions and minimal influence on the gross crystal structure.

Crystalline multicomponent compounds involving hexaammine cobalt(iii) cations

“…As mentioned above, the analysis of CSD 19 has shown that a significant portion of the multicomponent compounds containing the complex cation [Co(NH 3 ) 6 ] 3+ are compounds that involve uncoordinated carboxylate anions, for example, o-phthalate, 29 pyridine-2,6-dicarboxylate 30 or oxalate, 28,35 as well as carboxylates coordinated to other metals, [29][30][31][47][48][49][50][51][52][53][54][55][56][57][58][59][60][61][62][63][64][65] but scarcely any Co III -hexaammine-containing compounds with N-donor species. Ultrasonic treatment of [Co(NH 3 ) 6 ]Cl 3 with 1,10-phenanthroline in the presence of triethanolamine in MeOH solution leads to crystallization of orange [Co(NH 3 ) 6 ]Cl 3 Á2(phen)Á 3H 2 O (1) with 55% yield, which to our knowledge is the first example of [Co(NH 3 ) 6 ] 3+ cations with exclusively N-donor organic components.…”

“…17 The study of crystal structures of multicomponent solids containing hexaammine cobalt(III) is limited. A detailed analysis of the Cambridge Structural Database (CSD version 5.4 + 4 updates) 19 of crystal structures shows the existence of hydrogenbonded metal complexes with [Co(NH 3 ) 6 ] 3+ cations and various derivatives of sulfonate, [20][21][22][23] disulfonate, [24][25][26] and trisulfonate anions, 27 mono-, di-, and tetracarboxylate anions, [28][29][30][31][32][33][34][35][36][37][38] 4-nitrophenolate, 39 ethylenediaminetetraacetate, 40 C 60 fulleride 41 and inorganic anions. [42][43][44] However, there is only one report of a bacterially produced natural carboxylic lasalocid A, which exhibits antibiotic and anticoccidial activities as well as a pronounced cardiovascular effect.…”

Crystal structures of deuterated sodium molybdate dihydrate and sodium tungstate dihydrate from time-of-flight neutron powder diffraction

“…Although it is more usual to find Na + in octahedral coordination, there are abundant examples of Na + in five-fold coordination, including instances where the NaO 5 polyhedron adopts a square-pyramidal arrangement (Beurskens & Jeffrey, 1961;Císařová ;Sharma et al, 2005;Smith & Wermuth, 2014;Aksenov et al, 2014) or the alternative trigonal-bipyramidal arrangement (Mereiter, 2013;Smith, 2013). A similar combination of NaO 6 and NaO 5 polyhedra to that found in the title compounds occurs in the closely-related hydrates Na 2 CrO 4 Á1.5H 2 O and Na 2 SeO 4 Á1.5H 2 O (Kahlenberg, 2012;Weil & Bonneau, 2014).…”