Crystal structure of (1,4,7,10,13,16-hexa-oxa-cycloocta-decane-κ6 O)potassium-μ-oxalato-tri-phenylstannate(IV), the first reported 18-crown-6-stabilized potassium salt of tri-phenyl-oxalatostannate

Abstract

The title complex, (1,4,7,10,13,16-hexa-oxa-cyclo-octa-decane-1κ⁶ O)(μ-oxalato-1κ² O ¹,O ²:2κ² O ^1',O ^2')triphenyl-2κ³ C-potassium(I)tin(IV), [KSn(C₆H₅)₃(C₂O₄)(C₁₂H₂₄O₆)] or K[18-Crown-6][(C₆H₅)₃SnO₄C₂], was synthesized. The complex consists of a potassium cation coordinated to the six oxygen atoms of a crown ether mol-ecule and the two oxygen atoms of the oxalatotri-phenyl-stannate anion. It crystallizes in the monoclinic crystal system within the space group P2₁. The tin atom is coordinated by one chelating oxalate ligand and three phenyl groups, forming a cis-trigonal-bipyramidal geometry around the tin atom. The cations and anions form ion pairs, linked through carbonyl coordination to the potassium atoms. The crystal structure features C-H⋯O hydrogen bonds between the oxygen atoms of the oxalate group and the hydrogen atoms of the phenyl groups, resulting in an infinite chain structure extending along a-axis direction. The primary inter-chain inter-actions are van der Waals forces.

Keywords: 18-crown-6; crystal Structure; oxalato; potassium; tri­phenyl­stannate.