Tin(II) and Tin(IV) Compounds with Scorpion-Shaped Ligands - Intramolecular N→Sn vs. Intermolecular O→Sn Coordination

The syntheses of new potentially tetradentate ligands of the type RN(CH2CMe2OH)2 (1, R = Me2NCH2CH2; 2, R = MeOCH2CH2), their tin(II) derivatives RN(CH2CMe2O)2Sn (3, R = Me2NCH2CH2; 4, R = MeOCH2CH2), the pentacarbonyltungsten complexes RN(CH2CMe2O)2SnW(CO)5 (5, R = Me2NCH2CH2; 6, R = MeOCH2CH2) and their oxidation products with bromine, RN(CH2CMe2O)2SnBr2 (7, R = Me2NCH2CH2; 8, R = MeOCH2CH2), are reported. The compounds were characterized by multinuclear NMR spectroscopy, elemental analysis, electrospray ionization mass spectrometry and single-crystal X-ray diffraction analysis. DFT calculations on compounds 3, 7 and 8 suggest the preference of dimeric over monomeric structures.