Co-ordination behaviour of a novel tristhiourea tripodal ligand; structural variations in a series of transition metal complexes

Synthesis, Crystal Structure and Cyclic Voltammetric Behavior of N-aroyl-N′-(4′-cyanophenyl)thioureas

Herein, two title compounds, N-benzoyl-N′-(4′-cyanophenyl)thiourea (1) and N-(4-nitrobenzoyl)-N′-(4′-cyanophenyl)thiourea (2) were synthesized in a high yield, via different applications of aroyl isocyanate and 4-aminobenzonitrile. The structure of the prepared compounds was characterized by elemental analysis and FT-IR, 1H, and 13C-NMR spectroscopic methods. The crystal structure of the title compound 1 was determined by an X-ray single-crystal technique and an intramolecular C=O…H-N hydrogen bond and intermolecular C=S…H-N and C=S…H-C hydrogen interactions, which were observed for the crystal structure. The molecular electrostatic potential (MEP) and the Mulliken atomic charges of title compounds 1 and 2 were theoretically calculated and interpreted. Cyclic voltammetric (CV) experiments for the compounds were performed with the glassy carbon electrode. The reduction in potential values of the different functional groups such as nitro and cyano in title compounds were investigated using CV curves.

Synthesis, Resolution, and Absolute Configuration of Chiral Tris(2-pyridylmethyl)amine-Based Hemicryptophane Molecular Cages

The synthesis, characterization, and chiroptical properties of a new class of hemicryptophane cages combining a cyclotriveratrylene unit and a tris(2-pyridylmethyl)amine (TPA) moiety are reported. Changing the linkers between these two units allows for the modification of the size and shape of the cavity. The synthesis is straightforward and efficient, providing gram-scale of cage compounds. The racemic mixture of each hemicryptophane host can be readily resolved by chiral HPLC, giving an easy access to the enantiopure molecular cages of which absolute configurations have been assigned by ECD spectroscopy. These new hemicryptophanes are available chemical platforms ready to use for various purposes due to the versatile metal complexation properties of the TPA unit. A Zn(II)@hemicryptophane complex has been obtained and used as a heteroditopic host for the selective recognition of zwitterionic guests.