Highly symmetrical 24-membered macrocyclic organoantimony(V) complexes constructed from Schiff base ligands possessing two terminal carboxyl groups

Two novel organoantimony(V) complexes [Ph3SbLa]2 (1) and [Ph3SbLb]2 (2) (H2La = 5-{[(2-carboxyphenyl)methylene]amino}-4-chlorobenzoic acid, and H2Lb = 5-{[(2-carboxyphenyl)methylene]amino}-2-chlorobenzoic acid) have been synthesized by the reaction of triphenylantimony dichloride and Schiff base ligands with the ratio of 1:1, and characterized by elemental analysis, IR, 1H and 13C NMR spectroscopy. X-ray single-crystal diffraction analyses reveal that two highly symmetrical 24-membered macrocyclic organoantimony derivatives were found unprecedentedly, in which two antimony atoms are bridged by four terminal carboxyl groups of the Schiff base ligands, and antimony atoms exhibit typical five-coordinated trigonal-bipyramid geometry with two carboxyl oxygen atoms occupying the axial positions. In complexes 1 and 2, there exist several types of secondary interactions (C–H…π, C–Cl…π and C-H…Cl), which contribute to the formation of a 1D infinite chain in 1 and a 2D supramolecular network structure in 2 in their crystal structures, respectively.

Two novel organoantimony(V) complexes [Ph3SbLa]2 and [Ph3SbLb]2 have been synthesized by the reaction of triphenylantimony dichloride and Schiff base ligands possessing two terminal carboxyl groups, and characterized by elemental analysis, IR, 1H and 13C NMR spectroscopy. Structural analyses reveal that two highly symmetrical 24-membered macrocyclic organoatimony derivatives were obtained unprecedentedly.Figure optionsDownload as PowerPoint slideResearch highlights
► Two highly symmetrical 24-membered macrocyclic organoantimony(V).
► Several types of secondary interactions (C-H…π, C-Cl…π and C-H…Cl).
► A 1D infinite chain or 2D supramolecular network structure formed by secondary interaction.