Macrocyclic organotin(IV) carboxylates based on benzenedicarboxylic acid derivatives: Syntheses, crystal structures and antitumor activities

Six new organotin carboxylates based on 1,3-benzenedicarboxylic acid and 1,4-benzenedicarboxylic acid derivatives, namely (Ph3Sn)2(2,5-L1)(C2H5OH)2 (1) (2,5-H2L1 = 2,5-dibenzoylterephthalic acid), (Ph3Sn)2(2,5-L2)(C2H5OH)2 (2) (2,5-H2L2 = 2,5-bis(4-methylbenzoyl)terephthalic acid), (Ph3Sn)2(2,5-L3)(C2H5OH)2 (3) (2,5-H2L3 = 2,5-bis(4-ethylbenzoyl)terephthalic acid), [(n-Bu2Sn)4(4,6-L1)O2(OH)(OC2H5)]2·2(C2H5OH) (4) (4,6- H2L1 = 4,6-dibenzoylisophthalic acid), [(n-Bu2Sn)4(4,6-L1)O2(OH)(OC4H9)]2·2(C4H9OH) (5) and [(n-Bu2Sn)4(4,6-L2)O2(OH)(OC2H5)]2·2(C2H5OH) (6) (4,6-H2L2 = 4,6-bis(4-methylbenzoyl)isophthalic acid), have been synthesized. All the organotin carboxylates have been characterized by elemental analysis, IR, 1H and 13C NMR spectroscopy and X-ray crystallography diffraction analyses. The structural analysis reveals that complexes 1–3 show similar structures, containing binuclear triorganotin skeletons. The significant intermolecular O–H⋯O hydrogen bonds linked the complexes 1–3 to form a novel 2D network polymer with 38-member macrocycles. In complexes 4–6, two Sn4O4 ladders are connected by two 1,3-benzenedicarboxylic acid derivatives to yield ladder-like octanuclear architectures and form macrocycle with 24 atoms. In addition, the antitumor activities of complexes 1–6 have been studied.

Macrocyclic organotin carboxylates based on 1,3-benzenedicarboxylic acid and 1,4-benzenedicarboxylic acid derivatives have been synthesized and characterized by elemental analysis, IR, NMR spectroscopy and X-ray diffraction analyses.Figure optionsDownload as PowerPoint slideHighlights
► Organotin carboxylates are synthesized with benzenedicarboxylic acid derivatives.
► Two isomers of carboxylate ligand were separated by fractional crystallization.
► Two Sn4O4 ladders are connected by two ligands to form macrocycle.