Neutral Pentacoordinate Silicon(IV) Complexes with Si ClO 2 NC, Si ClON 2 C, Si O 3 NC, or Si O 2 N 2 C Skeletons

The neutral pentacoordinate silicon(IV) complexes 3 ( Si ClO 2 NC skeleton), 4 ( Si O 3 NC), 5 ( Si O 2 N 2 C), and 6 ( Si ClON 2 C) were synthesized. Compounds 3 – 6 contain a tridentate dianionic O , N , O ( 3 – 5 ) or O , N , N ligand ( 6 ), a phenyl ligand, and a (pseudo‐)halogeno ( 3 , 5 , 6 ) or trifluoromethanesulfonato ligand ( 4 ). Compounds 3 – 6 were characterized by single‐crystal X‐ray diffraction and solid‐state and solution NMR spectroscopy. According to these studies, the coordination number of the silicon atom in the solid complexes 3 – 6 is retained in solution.