| Thiacalix[4]arenes are cyclic oligomers composed of four S atoms whichbridge four phenol units.Generally,thiacalix[4]arene in the cone conformation can coordinate with metal ions to form shuttlecock-like Mx-thiacalix[4]arene(M is some transition metal ions;x is mainly 3 or 4)which is secondary building units(SBUs).The SBUs can combine with auxiliary ligands with specific functions to assemble of functional compounds with novel structures.In this thesis,7 coordination clusters were synthesized from p-tert-butylthiacalix[4]arene(H4TC4A)/p-H-thiacalix[4]arene(H4T4A),purine auxiliary,and coblat salts(Co Cl2·6H2O/Co(Ac)2·4H2O)under solvothermal conditions.These clusters can be regarded as the purine-functionalized Co4-thiacalixarene SBUs bonded by other linkages,eg.additional metal ions,purines.These clusters were characterized by SCXRD,PXRD,TGA,FT-IR,UV-vis and other methods.The synthesis conditions of the clusters were discussed,and the electrocatalysis and photocatalytic activity were tested.The main work in this thesis is as follows:Seven Co-based nanocluster compounds have been synthesized from H4TC4A(for Co10-2 and Co10-3)/H4T4A(for Co4,Co10-1,Co14-1,Co14-2 and Co14-3).The different clusters can be achieved by changing the above raw matrials.In these structures,the Co10 compounds are similar strutures and consist of two Co4-T4A-HAD/Co4-TC4A-HAD SBUs and two bridging cobalt entities.The adenine-functionalized Co4-T4A entity is a common secondary building unit(SBU).The cluster Co14-1 is formed from two Co4(T4A)Cl(HCOO)(AD)2 units and one Co4(T4A)Cl(HCOO)(HAD)2 unit,which all three are linked into an unsymmetrical triangular array by two additional,triply bridging AD-ligands,with the two Co4(T4A)Cl(HCOO)(AD)2 units being further bridged by{Co Cl2}entities bound to their AD-ligands.The cluster Co14-2,obtained from a different solvent mixture,is a trigonal cage formed from three Co4(T4A)Cl(HCOO)2(AD)2 units linked by imidazolate-N coordination to{Co Cl/H2O}bridgeheads.Substitution of DMA for DMF co-solvent results in a similar trigonal cage,Co14-3,but one of lower symmetry in that it is formed from two Co4(T4A)(OH)(CH3COO)2(AD)2 units and one Co4(T4A)(OH)(CH3COO)(H2O)2(AD)2 unit linked by imidazolate-N coordination to two Co(CH3COO)bridgeheads.The solid-state UV-vis light absorption of these seven clusters were invetigated.The absorption of the seven clusters can reach 700 nm,and the band gap is 2.98 e V(Co4),2.67 e V(Co10-1),and 2.76 e V(Co10-2),2.77 e V(Co10-3),2.56 e V(Co14-1),2.76 e V(Co14-2)and 2.71 e V(Co14-3),respectively.The porosity of the three Co14 analogues was characterized by the N2adsorption,which indicated packing-struture-dependent BET surface areas and Langmuir surface areas.The electrochemical OER activities were also tested and Co14-2 cluster presented OER overpotential of 298.8 m V at a current density of 10 m A/cm~2with 3.0 mg/cm~2 loading.In view of better visible light absorption and the materials containing adenine ligands which showed good photocatalytic reduction of CO2reaction(CO2RR)activity,the cooresponding experiments for the selected clusters were carried out.Unfortunately,it was found that only CO2converting to HCOO-and the coordinated HCOO-exchanging were observed for Co14-1 and Co14-2 clusters.The successful substitution of the coordinated HCOO-with CH3COO-as well as the created liable water coordination in Co14-3 has not efficiently facilitated the photocatalytic CO2 conversion.However,the Co10-2 and Co10-3complexes showed efficient photocatalytic reduction of CO2to HCOOH in pure water with 103?mol/g and 733?mol/g ability,respectively. |
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