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

Article abstract of DOI:10.1016/j.jorganchem.2013.01.017

A series of organotin carboxylates based on amide carboxylic acids: (Ph₃Sn)(L¹)·C₇H₈ (1) (L ¹ = (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)(L ³)·C₇H₈ (3) (L³ = N-phenyl-phthalamic acid), (n-Bu₂Sn)(L¹) ₂·C₇H₈ (4), (n-Bu₂Sn)(L ⁴)₂ (5) (L⁴ = 4-(1,3-dioxo-1,3-dihydro- isoindol-2-yl)-benzoic acid), [(n-Bu₂Sn)₂(L ²)O]₂·C₇H₈ (6), {[n-Bu ₂Sn(L⁵)]₂O}₂·C ₇H₈ (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.