C4-Ferrocenylsilyl-bridged and -substituted N-heterocyclic carbenes: complexation of germanium chloride.

While the 1 : 1 reaction of C4-trichlorosilyl-functionalized N-heterocyclic carbene (NHC) (2) with [(η5 -C5 H4 Li)2 Fe]3 [TMEDA]2 (3) gives C4-sila[1]ferrocenophane-substituted NHC (4), C4-ferrocenylsilyl-bridged bis-NHC (6) is synthesized by combining 3 with C4-chlorodimethylsilyl-functionalized NHC (5) in a 1 : 2 ratio, (compound 5 is prepared by reaction of the anionic N-heterocyclic dicarbene (NHDC) [:C{[N(2,6-Pri 2 C6 H3 )]2 CHCLi}]n (1) with Me2 SiCl2 ). In addition, ligand 4- and 6-based GeCl2 complexes (7 and 8) are also synthesized. Compounds 4-8 have been characterized by1 H,13 C, and29 Si NMR spectroscopy and single crystal X-ray diffraction.