Organotin(IV) carboxylates based on amide carboxylic acids: Syntheses, crystal structures and characterizations

A series of organotin carboxylates based on amide carboxylic acids: (Ph3Sn)(L1)·C7H8 (1) (L1 = (1,3-dioxo-1H,3H-benzo[de]isoquinolin-2-yl)-acetic acid), (Ph3Sn)(L2) (2) (L2 = 3-(1,3-dioxo-1H,3H-benzo[de]isoquinolin-2-yl)-benzoic acid), (Ph3Sn)(L3)·C7H8 (3) (L3 = N-phenyl-phthalamic acid), (n-Bu2Sn)(L1)2·C7H8 (4), (n-Bu2Sn)(L4)2 (5) (L4 = 4-(1,3-dioxo-1,3-dihydro-isoindol-2-yl)-benzoic acid), [(n-Bu2Sn)2(L2)O]2·C7H8 (6), {[n-Bu2Sn(L5)]2O}2·C7H8 (7) (L5 = 4-(1,3-dioxo-1H,3H-benzo[de]isoquinolin-2-yl)-benzoic acid) were synthesized with toluene being used as solvent in the reaction and characterized by elemental analysis, IR, 1H and 13C NMR spectroscopy and X-ray crystallography diffraction analyses. Complexes 1–5 are monomers in which 1–3 are triphenlytin carboxylates while 4 and 5 are dibutyltin carboxylates possessing crystallographically imposed two-fold symmetry. Complexes 6 and 7 are dimeric carboxylate tetraorganodistannoxanes and show a “ladder-like” molecular structure. Ligands in 1–3 and 6 adopt unidentate chelating mode and in 4 and 5 they are bidentate, while for 7 both of the chelate coordination modes exist. Intermolecular hydrogen bonds and π⋯π interactions help complexes 1–7 build their respective supramolecular structures which are discussed in detail. It is found that amide carboxylic acids are apt to adopt various coordination modes and lead diverse molecular architectures for organotin carboxylates.