Synthesis and characterization of group 14 dialkylmetal chalcogenones (R2M)-M-N=E [R-N = CH(SiMe3)C9H6N-8 or CPh(SiMe3)C5H4N-2; M = Ge or Sn; E = S, Se, or Te]

Treatment of group 14 metal dialkyl MR2N (M = Ge or Sn) with elemental chal cogens (sulfur, selenium, or tellurium) in THF afforded the corresponding c halcogenones (R2M)-M-N=E [R-N = CPh(SiMe3)C5H4N-2; M = Ge; E =S (4), Se (5) , Te (6); M = Sn; E = S (7), Se (8); R-N = CH(SiMe3)C9H6N-8, M = Sn; E = Se (10), Te (11)]. In contrast, a sulfide-bridged dimer [(R2Sn)-Sn-N(mu-S)](2 ) (9) was obtained from similar reaction of SnR2N [R-N = CH(SiMe3)C9H6N-8] with elemental sulfur. These chalcogenones have been characterized by eleme ntal analysis, H-1, C-13, Sn-119, Se-77, and Te-125 NMR, and mass spectrosc opy. X-ray structure of 5, 8, 9, 10, and 11 have been determined. It was re vealed that compounds 5, 8, 10, and 11 consist of a terminal metal-chalcoge n bond with the ligands R-N acting in a C,N-chelate fashion, except for 9, which is a sulfide-bridged dimer.