Two new calix[4]resorcinarene-based coordination cages adjusted by metal ions for the Knoevenagel condensation reaction. Issue 28 (6th July 2021)

• Record Type: Journal Article
• Authors: Pei, Wen-Yuan; Lu, Bing-Bing; Yang, Jin; Wang, Tianqi; Ma, Jian-Fang
• Is Part Of: Dalton transactions. Volume 50:Issue 28(2021)
• Page Start: 9942
• Page End: 9948
• Publication Date: 2021-07-06
• Subjects: Chemistry, Inorganic -- Periodicals; Chemistry, Physical and theoretical -- Periodicals; Chemistry, Inorganic -- Periodicals; 546.05
• DOI: 10.1039/d1dt01139a
• Languages: English
• ISSNs: 1477-9226

Abstract

Abstract : Two new calix[4]resorcinarene-based metal-coordinated cages have been synthesized through tuning metal ions, where they featured catalytic activities for the Knoevenagel condensation reaction under solvent-free conditions. Abstract : Two new calix[4]resorcinarene-based coordination cages, namely, [Zn4 (TPC4R)(PDC)4 ]·2DMF·6H2 O (1-Zn ) and [In11 (TPC4R)2 (PDC)16 (μ2 -OH)2 (H2 O)2 ]·[(CH3 )2 NH2 ]·8DMF·20H2 O·EtOH (2-In ), have been synthesized via solvothermal reactions (TPC4R = tetra(2-(4 H -pyrazol-3-yl)pyridine)calix[4]resorcinarene, H2 PDC = 3, 5-pyridinedicarboxylic acid, DMF = N, N ′-dimethylformamide). By carefully tuning different metal ions, two structurally different cages 1-Zn and 2-In were achieved. The former shows a bowl-shaped structure, while the latter features a dumbbell-like structure. After activation, they exhibited unsaturated Zn(ii ) or In(iii ) Lewis acid sites and the free nitrogen Lewis base sites of the PDC 2− . Therefore, they were employed as catalysts for the Knoevenagel condensation reaction in the absence of a solvent. Particularly, 1-Zn featured high structural stability and enhanced the catalytic activity.