Synthesis and spectroscopic studies of diorganotin derivatives with 2-[(2,6-dimethylphenyl)amino]benzoic acid. Crystal and molecular structure of the first complexes of 2-[(2,6-dimethylphenyl)amino]benzoic acid. Crystal and molecular structures of 1,2:3,4-di- μ2-2-[(2,6-dimethylphenyl)amino]-benzoato- O,O-1,3-bis-2-[(2,6-dimethylphenyl)amino]benzoato- O-1,2,4:2,3,4-di- μ3-oxo-tetrakis[di-butyltin(IV)] and bis-2-[(2,6-dimethylphenyl)amino]benzoato-di- n-butyltin(IV)

Abstract

The complexes [Bu 2(DMPA)SnOSn(DMPA)Bu 2] 2 ( 2) and [Bu 2Sn(DMPA) 2] ( 3), where HDMPA is 2-[bis(2,6-dimethylphenyl)amino]benzoic acid, have been prepared and structurally characterized by means of, vibrational, ultra-violet, 1H and 13C NMR spectroscopies. The crystal structure of complexes 2 and 3 have been determined by X-ray crystallography. Three distannoxane rings are present to the dimeric tetraorganodistannoxane of planar ladder arrangement of 2. The structure is centro-symmetric and features a central rhombus Sn 2O 2 unit with two additional tin atoms linked at the O atoms. Five- and six-coordinated tin centers are present in the dimmer distannoxane. The crystal structure of 3 consists of discrete molecular units and the two modeprononated ligands are co-ordinated to the SnBu 2 fragment. The ligands act as anisobidentate chelating agents, thus rendering the tin atom six-co-ordinated. Significant π→π, C–H-π stacking interactions and intramolecular hydrogen bonds stabilize the structures 2 and 3. The polar imino hydrogen atom participates in intramolecular hydrogen bonds. Complexes 2 and 3 are self-assembled via π→π C–H-π and stacking interactions.