Synthesis, Structure And Electrochemical Properties Of Multi- Component Metal-Calixarene Cluster Compounds

The multidentate macrocyclic thiacalix[4]arene ligand and the derivatives have been used to form M₄-TC4A second building units?SBU?,which can be coordinated by auxiliary ligands to fabricate facinating metal cluters.In this thesis,nine new multi-component matal clusters have been synthesized by the main ligand p-tert-butylthiacalix[4]arene?H₄TC4A?/p-tert-butylsulfonylcalix[4]arene?H₄TC4A-SO₂?and different auxiliary ligands with various components.The complexes were characterized by X-ray single crystal diffraction?SCD?,PXRD,TGA,FT-IR and other methods.The matal clusters were also structural determined and multi-component metal-calixarene nuclear cluster compounds was studied on the electrochemical oxygen evolution reaction and hydrogen evolution reaction.1.H₄TC4A was chosen as the main ligand,?NH₄?₂MoS₂O₂ as an auxiliary ligand and cobalt acetate or zinc acetate or nickel acetate to synthesize three mixedmetalclustersundersolvothermalconditions,?NH₄?{M₄?TC4A?Cl[?MoO₂?₂S?CH₃O?]₄}?M=Co?1?,Ni?2?,Zn?3??.OER electrodes that can be used in alkaline media were successfully prepared by directly loading of the clusters onto the nickel foam?NF?and copper foam?CF?substrates,respectively,which were characterized by XPS,EDX,SEM.The OER experiments were carried out in 1 M KOH and the Co₄Mo₈/NF catalyst exhibited the best electrocatalytic activity and long-term catalytic stability.2.Four quadrilateral shaped matal cage clusters have been obtained by linkage of auxiliary ligands with different substituent groups?H₂L1?NH₂?,H₂L2?OH?,H₂L3?H??with Co₄-TC4A or Co₄-TC4A-SO₂ SUB.The structure was determined by single crystal X-ray diffraction.Pt source was anchored to the cage compound by post-modification and hydrogen evolution reaction?HER?investigations were carried out.The single crystal structure of Pt@Co₁₆^?-TC4A-SO₂-NH₂ was structurally determined by SCD.Pt atoms can be anchored to Co₁₆^?-TC4A-SO₂-NH₂ clusters by the coordination of-NH₂groups,preventing the aggregation of Pt nanoparticles,resulting the best HER performances among all the prepared elecrodes.The HER of Co₁₆^?-TC4A-SO₂-NH₂@Pt has lower initial potential and smaller overpotential than that of commercial Pt/C.The catalytic performance of metal clusters with the same calixarene decreases with decreasing the electron donating ability of the ancillary ligand.Metal clusters built from H₄TC4A-SO₂ showed better HER activities comparing with that from H₄TC4A with the same ancillary ligand?NH₂?,the former of which with larger cage cavities may provid the superior catalytic activties.3.A new H₄TC4A-SO₂-supported tetrahedral Co₁₆6 cage cluster?9?was synthesized from CoCl₂·6H₂O,H₄TC4A-SO₂ and asymmetric3-?2H-tetrazol-5-yl?benzoic acid?H₂L4?under solvothermal condition.Directly loading 9 onto carbon paper?9/CP?as a working electrode exhibited efficient oxygen evolution reaction?OER?catalytic performance.In 1 M KOH,9/CP gained a current density of 10.0 mA/cm² at a catalytic reaction overpotential of 343.8 mV,a tafel slope of 79.31 mV/dec,and catalytic stability for 12 h.