Framework tetrarhodanomercurate complexes of Mn(II), Fe(II), Cd(II) with nicotinamide: synthesis and crystal structure

New bimetallic complexes of the composition [MHg(CHNO)(SCN)] have been synthesized, where M = Mn (I), Fe (II), Cd (III); CHNO is nicotinamide (NA). The compounds were obtained from aqueous solutions and studied by CHNS/O analysis, IR spectroscopy, inductively coupled plasma optical emission spectrometry (ICP-OES) and X-ray diffraction analysis (XRD). Compounds I–III are isostructural and crystallize in the monoclinic syngony (space group C2/c). The coordination environment of the M atom is formed by two donor nitrogen atoms of two monodentately coordinated NA and four nitrogen atoms of the SCN groups, which form bridges between the M and Hg ions, connecting them into a three-dimensional framework. Hg ions have a tetrahedral coordination environment consisting of four S atoms of four SCN groups.