Novel pentacoordinate silicon compounds bearing [Si-N-C-N-C-N] chelate ring derived from biguanide ligands

The reactions between secondary carbosilanes 1-3 and 1-propylbiguanide/1-phenylbiguanide, H₆bigR proceed via SiH/NH dehydrocoupling and afford 1,4-bis(silyl)-5-propyl/phenylbiguanides with the general formula (R¹R²₂SiCH₂CH₂SiMeH)₂·H₄bigR, R¹=Ph, R²=Me, R=ⁿPr (4), R=Ph (5); R¹=Me, R²=Ph, R=ⁿPr (6), R¹=R²=Et, R=Ph (7)]. These compounds represent a new family of pentacoordinate silicon derivatives comprising of Si-N-C-N-C-N] chelate ring and have been characterized by elemental analysis, FAB mass, IR and multinuclear (¹H, ¹³C and ²⁹Si) NMR spectral studies.