| Abstrakt: |
The reduction of N,C,N-chelated bismuth chlorides [C6H3-2,6-(CHNR)2]BiCl2 [where R= tBu ( 1), 2′,6′-Me2C6H3 ( 2), or 4′-Me2NC6H4 ( 3)] or N,C-chelated analogues [C6H2-2-(CHN-2′,6′- iPr2C6H3)-4,6-( tBu)2]BiCl2 ( 4) and [C6H2-2-(CH2NEt2)-4,6-( tBu)2]BiCl2 ( 5) is reported. Reduction of compounds 1- 3 gave monomeric N,C,N-chelated bismuthinidenes [C6H3-2,6-(CHNR)2]Bi [where R= tBu ( 6), 2′,6′-Me2C6H3 ( 7) or 4′-Me2NC6H4 ( 8)]. Similarly, the reduction of 4 led to the isolation of the compound [C6H2-2-(CHN-2′,6′- iPr2C6H3)-4,6-( tBu)2]Bi ( 9) as an unprecedented two-coordinated bismuthinidene that has been structurally characterized. In contrast, the dibismuthene {[C6H2-2-(CH2NEt2)-4,6-( tBu)2]Bi}2 ( 10) was obtained by the reduction of 5. Compounds 6- 10 were characterized by using 1H and 13C NMR spectroscopy and their structures, except for 7, were determined with the help of single-crystal X-ray diffraction analysis. It is clear that the structure of the reduced products (bismuthinidene versus dibismuthene) is ligand-dependent and particularly influenced by the strength of the N→Bi intramolecular interaction(s). Therefore, a theoretical survey describing the bonding situation in the studied compounds and related bismuth(I) systems is included. Importantly, we found that the C3NBi chelating ring in the two-coordinated bismuthinidene 9 exhibits significant aromatic character by delocalization of the bismuth lone pair. [ABSTRACT FROM AUTHOR] |
