The trinuclear platinum(ii) complex in Vèzes’ red salt as a building block of coordination polymers

Abstract

One-dimensional (1D) and three-dimensional (3D) coordination polymers comprising triangular [Pt₃(NO₂)₆(μ₃-O)]²⁻ ([Pt3]²⁻) units were prepared from K₂[Pt3]·3H₂O (1), also known as Vèzes’ red salt. The reaction between 1 and excess 18-crown-6 ether afforded the 1D coordination polymer [K(18-crown-6)]₂[Pt3] (2), whereas the reaction between 1, excess 18-crown-6 ether, and AgPF₆ afforded the 1D coordination polymer [Ag(18-crown-6)]₂[Pt3]·(CH₃)₂CO (3). However, the reaction between 1 and equimolar amounts of 18-crown-6 and AgPF₆ afforded the 3D coordination polymer [Ag₂(18-crown-6)][Pt3]·(CH₃)₂CO (4). Furthermore, the 3D coordination polymer [Ag₂Pt₃(μ₃-O)(NO₂)₆((CH₃)₂CO)₂]·(CH₃)₂CO (5) containing three Pt²⁺ → Ag⁺ dative bonds was obtained by the reaction of 1, Bu₄NPF₆, and AgPF₆. The N₂, O₂, and CO₂ gas absorption isotherms of 1–5 were obtained, revealing that the dry crystals of 4 exhibit a selective CO₂ absorption ability.