The facile formation of boron‐nitrogen bridges allows the one‐step assembly of oligonuclear organometallic complexes. By the reaction of 1‐(dibromoboryl)ferrocene (1a) and 1,1′‐bis(dibromoboryl)ferrocene (1b) with 1‐[(dimethylamino)methyl]ferrocene (2) and (η6‐aniline)tricarbonylchromium derivatives (3, 4) dinuclear to pentanuclear units (5–10) were obtained. The homodimetallic compound FcBBr2‐NMe2CH2Fc (5, Fc: ferrocene) closely resembles a propylene‐bridged complex. Its dative B‐N link is stable at temperatures as high as 100°C. Each of the heterooligonuclear aggregates 7–10 is tied together by covalent B‐N bonds, which are isoelectronic with ethylene bridges. In FcB(Br)‐N(Me)Bct [7, Bct: (η6‐C6H5)Cr(CO3)] and 1,1′‐Fc[B(Br)‐N(Me)Bct]2 (9) B‐N π bonding dominates over the N‐Bct π interaction as indicated by spectroscopical data and an X‐ray analysis of 9. The N‐lithiated compounds BctNRLi (4a, b; R = H, Me) possess a remarkably increased N‐Bct π donation compared to the protonated parent compounds, which results in a further perturbation of the local C3v symmetry of the (C6H5)Cr(CO3) framework.
All Science Journal Classification (ASJC) codes
- Boron‐nitrogen bridges
- Chromium, (aniline)tricarbonyl‐
- Polynuclear complexes