Chiral self-assembly of triorganotin complexes: Syntheses, characterization, crystal structures and antitumor activity of organotin(IV) complexes containing (R)-(+)-methylsuccinic acid, (S)-(+)-methylglutaric acid and l-(−)-malic acid ligands

Six new chiral triorganotin(IV) complexes, {(R3Sn)2[C3H6(COO)2]}n (R = Me: 1; Bu: 2), {(R3Sn)2[C4H8(COO)2]}n (R = Me: 3; Bu: 4), and {(R3Sn)2[C2H4O(COO)2]}n (R = Me: 5; Bu: 6) have been prepared by treatment of (R)-(+)-methylsuccinic acid, (S)-(+)-methylglutaric acid and l-(−)-malic acid, with the corresponding R3SnCl (R = Me, Bu) and sodium ethoxide in methanol. All the complexes were characterized by elemental analysis, FT-IR, NMR (1H, 13C, 119Sn) spectroscopy and TGA. Except for 3, all of the complexes were also characterized by X-ray crystallography. The structural analyses reveal that complexes 1 and 5 have 2D network structures in which (R)-(+)-methylsuccinic acid and l-(−)-malic acid act as tetradentate ligands coordinated to trimethyltin(IV) ions. Complexes 2 and 4 have 3D metal–organic framework structures in which the deprotoned acids serve as tetradentate ligands. Complex 6 adopts a 1D zigzag chain structure and forms a 2D supramolecular framework through intermolecular C–H⋯O interactions. In addition, the antitumor activities of complexes 1–6 have been studied. We also have measured the specific rotation of the chiral dicarboxylic acids and the organotin derivatives.

Graphical abstractSix new chiral triorganotin(IV) complexes, {(R3Sn)2[C3H6(COO)2]}n (R = Me: 1; Bu: 2), {(R3Sn)2[C4H8(COO)2]}n (R = Me: 3; Bu: 4) and {(R3Sn)2[C2H4O(COO)2]}n (R = Me: 5; Bu: 6), have been prepared by treatment of (R)-(+)-methylsuccinic acid, (S)-(+)-methylglutaric acid and l-(−)-malic acid, with the corresponding R3SnCl (R = Me, Bu) and sodium ethoxide in methanol. All the complexes were characterized by elemental analysis, FT-IR, NMR (1H, 13C, 119Sn) spectroscopy and TGA. Except for 3, all of the complexes were also characterized by X-ray crystallography. In addition, the antitumor activities of complexes 1–6 have been studied.Figure optionsDownload full-size imageDownload as PowerPoint slide