Intramolecularly C,N-Coordinated Homo- and Heteroleptic Organostannylenes

The synthesis of the C,N-chelated homoleptic organotetrylenes (L-1)(2)E (<bold>1</bold>, E = Sn; <bold>2</bold>, E = Pb) and of the tungsten pentacarbonyl complex (L-1)(2)SnW(CO)(5) (<bold>3</bold>), containing the sterically demanding C,N-chelating ligand L-1 (L-1 = [2-{(C6H3-2,6-Pr-2(i))N-CH}C6H4]-) is reported. In contrast, the use of the C,N-chelated ligand L-2 (L-2 = [2-{(C6H3-2,6-Pr-2(i))N-C(Me)}C6H2(OCH2O)]-) provided either the homoleptic stannylene (L-2)(2)Sn (<bold>4</bold>) or the C,N-chelated chlorostannylene (L-2)SnCl (<bold>5</bold>). All attempts to convert the latter into the corresponding ditin compound [L2Sn](2) failed, however, and resulted in the isolation of <bold>4</bold> and elemental tin. These attempts also provided the unprecedented complex [2-{(C6H3-2,6-Pr-2(i))N-C(Me)}C6H2(OCH2O)][2-{(C6H3-2,6-Pr-2(i))NHCH(Me)}C6H2(OCH2O)]Sn (<bold>6</bold>).