Second-sphere hydrogen-bonding in heteroditopic mercaptopyridinium copper(I) frameworks

Abstract

A series of Cu(I) complexes of 4-mercaptopyridine (LH) are reported that form three-dimensional hydrogen-bonded frameworks in the solid-state. The 4-mercaptopyridine ligands co-ordinate to the Cu(I) cations via thiolate donors, leaving a pyridinium hydrogen-bond donor available for interaction with the relevant counter-anions. Four new Cu(I) complexes, [Cu₂(LH)₆]·2Cl 1, [Cu₂(LH)₆]·SiF₆·2MeOH 2, [Cu₄(LH)₁₀]·4NO₃·MeOH·H₂O 3 and {[Cu₆(LH)₁₃]·2BF₄·2SiF₆·7.5MeOH}_∞4 are reported and have been structurally characterised by single crystal X-ray diffraction. In each case hydrogen-bonded arrays are formed via N–H⋯anion hydrogen-bonds or by including hydrogen-bonding to guest solvent molecules. Whereas compound 1 adopts a rutile-like structure with [Cu₂(LH)₆]²⁺ and Cl⁻ nodes adopting six- and three-connected arrangements, respectively, compounds 2 and 3 adopt six-connected nets of α-Po (4¹²6³) topology. Compound 4 forms a thiolate bridged co-ordination polymer constructed from repeating units of six Cu(I) centres connected by ten bridging and three terminal thiolate-bound LH donors, with complex hydrogen-bonding observed between the polymer cation and counter-anions.