Cationic Cobaltammines as anion receptors: a convenient synthesis, characterization and X-ray structure of [CO(NH₃)₆]ClSeO₄·3H₂O

Abstract

Reddish-orange single crystals of hexaamminecobalt(III) chloride selenate trihydrate, [Co(NH 3 ) 6 ]ClSeO 4 Á 3H 2 O, have been prepared by reacting aqueous solutions of hexaamminecobalt(III) chloride and potassium selenate in a 1 : 1 molar ratio. The salt was characterized by elemental analyses, thermogravimetry, magnetic moment and spectroscopic studies (IR, electronic). A single crystal X-ray structure determination revealed that the title complex salt crystallizes in the orthorhombic space group Pnma with a ¼ 18.230(2), b ¼ 8.591(2), c ¼ 8.593(2) Å , V ¼ 1345.9(4) Å 3 , Z ¼ 4, R ¼ 0.0400 and R w ¼ 0.0980. In the salt the network of hydrogen bonds between the hexaamminecobalt(III) cation, water molecule, chloride and oxygen atoms of the selenate ion represents the second sphere coordination and also suggests that [Co(NH 3 ) 6 ] 3þ may be used as an anion receptor for the selenate ion.

First X-ray structure of hexaamminecobalt(III) salt with complex fluoroanion: Synthesis and characterization of [Co(NH3)6]X·SiF6·nH2O, where X=Cl, Br, I and NO3 and crystal structure of [Co(NH3)6]Cl·SiF6·2H2O

“…Strong absorption maxima observed for the [Co(NH 3 ) 6 ]ClÁSiF 6 Á2H 2 O are in good agreement with those of related salts such as hexaamminecobalt(III) chloride selenate trihydrate (l max 470; 340 nm)[10] and hexaamminecobalt(III) chloride dichromate monohydrate (l max 360; 260 nm, for dichromate…”

“…Although the synthesis and single crystal X-ray structure determinations of a variety of hexaamminecobalt(III) complex salts have been reported in the literature [2,3,[7][8][9], particularly with metal chloroanions [MCl 5 ] 2À and [MCl 6 ] 3À [1] but none with complex fluoroanion. In continuation of our interest [10][11][12][13] in hexaaminecobalt(III) complex salts the present work reports synthesis and spectroscopic studies of [Co(N H 3 ) 6 ]XSiF 6 ÁnH 2 O where X = Cl (n = 2), Br, I, NO 3 (n = 0) and single crystal X-ray structure determination of [Co(NH 3 ) 6 ]ClÁSiF 6 Á2H 2 O. The crystal lattice consists of discrete ions, [Co(NH 3 ) 6 ] 3+ , SiF 6 2À and Cl À and two water molecules.…”

“…It is stabilized by extensive hydrogen bonding besides electrostatic forces. We have already reported hexaamminecobalt(III) salts with inorganic oxo-anions [10][11][12] and organic oxo-anion [13].…”

“…Á3H 2 O[10] but the constituent groups are different. Crystal data and structure refinement parameters are given inTable 2.…”

Second sphere coordination in anion binding: Synthesis, spectroscopic characterization and single crystal X-ray structure determination of hexaamminecobalt(III) dichloride tetrafluoroborate

“…Although the synthesis and single crystal X-ray structure determinations of a variety of hexaamminecobalt ( 2À which was recently reported by our group [21]. The present work reports synthesis, spectroscopic studies and single crystal X-ray structure determination of [Co(NH 3 ) 6 ]Cl 2 ÁBF 4 in continuation of our interest [22] in hexaamminecobalt(III) complex salts. The title complex salt is stabilized by extensive hydrogen bonding besides electrostatic forces of attractions.…”