Unsymmetrical Bicentric Organotin Lewis Acids {Me2N(CH2)3}Ph(X)Sn(CH2)nSnPh2X (X = F, I; n = 1, 3): Syntheses and Structures

The syntheses of the intramolecularly coordinated organotin compounds {Me2N­(CH2)3}­Ph­(X)­SnCH2SnPh2X (3, X = I; 4, X = F) and {Me2N­(CH2)3}­Ph­(F)­Sn­(CH2)3SnPh2F (7) are reported. The compounds have been characterized by elemental analysis, electrospray mass spectrometry, 1H,1H DOSY (4), 13C, 19F, and 119Sn NMR spectroscopy, and single-crystal X-ray diffraction analysis. In the solid state, compound 4 is a head-to-tail dimer as a result of unsymmetrical Sn–F–Sn bridges, whereas compound 7 is a monomer with F→Sn intramolecular coordination, giving a six-membered ring. In solution, both 4 and 7 are monomeric. The reactions of both 4 and 7 with fluoride anion in CD2Cl2 have been investigated by variable-temperature 19F and 119Sn NMR spectroscopy.