Bis{(4-methylthio)phenylthio}methane as assembling ligand for the construction of Cu(I) and Hg(II) coordination polymers. Crystal structures and topological (AIM) analysis of the bonding

The novel 1D coordination polymer (CP) [{Cu(mu(2)-Br)(2)Cu}(mu-L2)(2)] CP2 has been obtained by reaction of the tetrakisthioether p-MeSC6H4SCH2SC6H4SMe-p (L2) with CuBr in a 1: 2 metal-to ligand ratio. In contrast to the previously described CP [{Cu(mu(2)-Br)(2)Cu}(mu-L1)(2)] CP1 obtained by reaction of the tetrakisthioether p-MeOC6H4SCH2SC6H4OMe-p (L1) with CuBr, the two independent extended 1D ribbons contain bent Cu(mu(2)-Br)(2)Cu units of the butterfly-type with short Cu center dot center dot center dot Cu separations of 2.679(1) and 2.613(1) angstrom. In contrast to the common planar rhomboid Cu(mu(2)-Br)(2)Cu cluster, this butterfly-shaped geometry of the core is without precedent. A luminescent material of composition [(Cu4I4)(mu-L2)](n) CP3 is formed by reaction of L2 with CuI in a 1: 4 ratio. The two-dimensional CP of stoichiometry [Hg2Br4(L2)](n) CP4 results from treatment of HgBr2 with this tetradentate thioether L2. The structure is of the adduct type with two crystallographically different covalently bound HgBr2 bars assembled in the first step into the chains through the weak Hg-S interactions involving one Hg atom and two S atoms. The chains thus constructed are further brought together through a supplementary Hg1-S1 inter-chain interactions leading to the 2D layered structure. Consequently the Hg1 atom may be considered as pentacoordinated, while the second Hg2 atom has a formal coordination number of 4. The nature of bonding in these CPs has been studied by the Quantum Theory of Atoms in Molecules (QT-AIM) approach allowing a clear classification of metal-ligand bonds and detection of pi-pi stacking interactions. (C) 2016 Elsevier B.V. All rights reserved.