Thiolato-Bridged Mn(I)-Based Tetranuclear Metalloclips: Host-Guest Induced Ligand Exchange and Post-assembly Heterometallation.

Thiolato-bridged Mn(I)-based molecular metalloclips [{(CO)3Mn(μ-SR)2Mn(CO)3}2(μ4-κ4-tee)] (H1-H3) (R = phenyl (H1), p-tolyl (H2), and benzyl (H3)) were obtained by self-assembly of Mn2(CO)10, diaryl disulfides, and flexible N,N,N',N'-tetrakis(ethylisonicotinoyl)ethylenediamine (tee). Metalloclips (H1-H3) were characterized by IR, UV-vis absorption, 1H NMR spectroscopy techniques, elemental analysis, and mass spectrometry. The crystal structure of molecular metalloclip H1 was determined by the single-crystal X-ray diffraction method. Host-guest induced ligand exchange between molecular metalloclips (H1-H3) and the ester-functionalized linear pyridyl linker phenyl-1,4-bis(isonicotinate) (pbin, G) was investigated, resulting in the formation of metallorectangles (R1-R3). The ligand-exchange process was studied by NMR and high-resolution mass spectrometry (HRMS). Furthermore, heterometallation of metalloclip H2 with Ni(II) and Pd(II) precursors afforded heterometallic supramolecular derivatives, whose electronic and structural features were investigated by UV-vis spectroscopy, FT-IR spectroscopy, and ESI-MS.