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

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.