Crystal structure of (1,4,7,10,13,16-hexa­oxa­cycloocta­decane-κ6O)potassium-μ-oxalato-tri­phenylstannate(IV), the first reported 18-crown-6-stabilized potassium salt of tri­phenyl­oxalatostannate

Abstract

The single-crystal X-ray structure of [(18-crown-6)K][SnPh₃(ox)] (ox = C₂O₄²⁻) is reported. Integrity between neighboring mol­ecules in the solid state is maintained by an array of C—H⋯O hydrogen bonds and C—H⋯π inter­actions.

The title complex, (1,4,7,10,13,16-hexa­oxa­cyclo­octa­decane-1κ⁶O)(μ-oxalato-1κ²O¹,O²:2κ²O^1′,O^2′)triphenyl-2κ³C-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 mol­ecule and the two oxygen atoms of the oxalatotri­phenyl­stannate 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 inter­actions are van der Waals forces.