| As a new type of crystalline material,metal oxygen clusters have potential applications in fluorescence,magnetism,gas adsorption,catalysis,etc.due to their novel and diverse structural characteristics.Among them,aluminum oxide clusters(Al OC)prepared with aluminum as a metal source have received widespread attention due to their light texture,non-toxicity,and strong chemical stability.However,extensive hydrolysis of aluminum salts usually results in the formation of amorphous metal oxide or hydroxide phases,which makes the preparation of aluminum-based crystalline materials challenging.Choosing a suitable chelating ligand to slow down the hydrolysis process(called coordination delayed hydrolysis(CDH))may be a good way to promote crystallization.We used this strategy to delay the hydrolysis process of Al3+and successfully synthesized compounds 1-14.This paper uses aluminum isopropoxide as the aluminum source,aromatic carboxylic acids(2-thiophenecarboxylic acid,3-thiophenecarboxylic acid,benzoic acid,salicylic acid,naphthoic acid,2-anthraquinone carboxylic acid,1-hydroxy-2-naphthoic acid,3-hydroxy-2-naphthoic acid)and alcohol amine(diethanolamine,diisopropanolamine)as ligands to synthesize a rich structure of aluminum oxide clusters.We obtained their single crystal structures and performed characterizations such as X-ray powder diffraction,infrared spectroscopy,ultraviolet spectroscopy,thermogravimetric analysis,fluorescence analysis,and scanning electron microscopy.The work of this paper mainly includes the following two aspects:(1)Successfully synthesized by solvothermal method using aluminum isopropoxide as aluminum source and aromatic carboxylic acid as ligand,represented by Al8(OH)2(?4-O)2(2-TCA)2(OEt)16 The octa-nuclear dimer aluminum oxide cluster compound and the deca-nuclear dimer aluminum oxide cluster compound represented by Al10(?4-O)2(SA)2(OEt)22 and their fluorescence performance were analyzed.Research and discussion.(2)Using the CDH strategy,the isopropanol produced by the rapid hydrolysis of aluminum isopropoxide competes with the alcohol amine ligand to influence crystal growth.In this paper,different alkanolamine concentrations was used as influence conditions to obtain aluminum-oxygen clusters with different nuclei and rich configurations.In-situ esterification reaction was also observed in the synthesis of[Al6(?3-O)2(DEA)4(PBA-iPr)2(OEt)2(OiPr)2·2HOiPr]cluster through the introduction of the second metal and was reasonable Propose a hypothesis of the reaction mechanism. |
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