abstract
Reactions of pyrazine-2,3-dicarboxylic acid (H(2)pzdc), cobalt nitrate and lanthanide (Ln) oxide under hydrothermal conditions result in four new 3d-4f heterometal coordination polymers, namely, [Ln(2)Co(pzdc)(4)(H2O)(6)]2H(2)O [Ln = La (1), Pr (2), Eu (3) and Gd (4)]. All compounds were characterized by elemental analysis, infrared spectroscopy, thermal gravimetric analysis, and X-ray diffraction. The compounds exhibit a three-dimensional (3D) brick-like structure with rectangular-shaped nano-scale channels along a axis direction, made up of wave-like layers containing [Ln(pzdc)](+) units, which are connected by one-dimensional (1D) chain of [Co(pzdc)(2)](2-). The catalytic properties of compounds 1 and 3 were investigated in the synthesis of cyanohydrins at room temperature under solventless conditions. They showed similar catalytic activities with very high conversions of benzaldehyde and high selectivity towards cyanohydrin. The control experiment without addition of the coordination polymers only reached 16% conversion. Other aldehydes could also be converted totally under shorter reaction times also with very high selectivities for the corresponding cyanohydrins. Compound 1 could also be recycled in another catalytic cycle.
keywords
METAL-ORGANIC FRAMEWORK; SINGLE-MOLECULE MAGNET; HYDROTHERMAL SYNTHESIS; MACROCYCLIC OXAMIDE; 3-DICARBOXYLIC ACID; COMPLEXES; LIGAND; SERIES; ADSORPTION; CHAINS
subject category
Chemistry
authors
Yang, TH; Silva, AR; Fu, LS; Shi, FN
our authors
Ana Rosa Silva
Principal Researcher
Lianshe Fu
Assistant Researcher
Tinghai Yang
Post-doc Fellowshipacknowledgements
F.-N. Shi acknowledges the project of National Natural Science Foundation of China (No. 21571132). T.-H. Yang acknowledges the Changzhou Sci&Tech Program (Grant No. CJ20179015) and Fundacao para a Ciencia e a Tecnologia (Portugal, Ref. SFRH/BPD/74582/2010). This work was also developed within the scope of the project CICECO-Aveiro Institute of Materials, POCI-01-0145-FEDER-007679 (FCT Ref. UID/CTM/50011/2013), financed by national funds through the FCT/MEC and when appropriate co-financed by FEDER under the PT2020 Partnership Agreement.