Novel mono- and bimetallic organotin(iv) compounds as potential linkers for coordination polymers

Abstract

The reaction of [2-(OCH)C₆H₄]Me₂SnCl (2), obtained by the hydrolysis of [2-{(CH₂O)₂CH}C₆H₄]Me₂SnCl (1), with the appropriate diamine, in a 2 : 1 molar ratio, in the absence of a solvent or catalyst, resulted in the bimetallic species ClSnMe₂[2-C₆H₄(4-CHN-1,1′-C₆H₄C₆H₄-4′-NCH)-2′-C₆H₄]Me₂SnCl (4) and ClSnMe₂[2-C₆H₄(CHNCH₂CH₂NCH)-2′-C₆H₄]Me₂SnCl (5). The reaction of 2 and 5 with KSCN gave the corresponding isothiocyanates [2-(OCH)C₆H₄]Me₂Sn(NCS) (3) and (SCN)SnMe₂[2-C₆H₄(CHNCH₂CH₂NCH)-2′-C₆H₄]Me₂Sn(NCS) (6). Treating 3 with H₂NCH₂CH₂NH₂ also resulted in the corresponding bimetallic compound 6. The reaction of 2 with sodium isonicotinate gave [2-(OCH)C₆H₄]Me₂SnO(O)CC₅H₄N-4 (7) and the subsequent treatment with ZnTPP (TPP = tetraphenylporphyrinate) led to the isolation of the heterobimetallic complex [{2-(OCH)C₆H₄}Me₂SnO(O)CC₅H₄N-4]ZnTPP (8). The compounds were characterized by multinuclear NMR spectroscopy and mass spectrometry in solution and IR spectroscopy in the solid state. The molecular structures for compounds 1–6 and 8 were established by single-crystal X-ray diffraction. For all compounds intramolecular O→Sn or N_imine→Sn coordination results in hypercoordinated species with a distorted trigonal bipyramidal (C,E)C₂SnX core (E = O, N_imine; X = Cl, N_{isothiocyanato}, O_{isonicotinato}). In the heterobimetallic complex 8 the zinc atom has a distorted square pyramidal geometry with the N_pyridyl atom at the apical position.