Generation of Group VI Piano‐Stool and Triple‐Decker Complexes from [(IMes) 2 PtH(Cl‐boratabenzene)] Species

Species [(IMes) 2 Pt(H)(1‐Cl‐2‐SiMe 3 –BC 5 H 4 )] ( 1 ) was used as the source of the Cl‐boratabenzene anion for coordination to group VI transition metals, resulting in the formation of piano‐stool complexes [(η 6 ‐1‐Cl‐2‐SiMe 3 –BC 5 H 4 )M(CO) 3 ] – [M = Cr ( 2 ), Mo ( 4 ), W ( 5 )] and a homodimetallic triple‐decker complex [(CO) 3 Cr(η 6 ‐1‐Cl‐2‐SiMe 3 –BC 5 H 4 )Cr(CO) 3 ] – ( 3 ). All species were spectroscopically characterized and the first X‐ray structure of a Cl‐boratabenzene species is reported.