1,1′-2-Trisubstituted Ferrocenyl Dibismuthines containing N / O Donor Pendant Arm

ABSTRACT New unsymmetrical chiral 1,1′-2-ferrocenyl dibismuthines [(C5H4)(BiPh2)]Fe(2-{Me2NCH(R)}C5H3)(BiPh2) containing 2-[(Me2NCH(R)] where R = Me (1) or H (3) pendant arm on ferrocenyl ring were synthesized. An unsymmetrical 1,1′-ferrocenyl-Bismuthine (5) in a low yield and 1,1′-2-ferrocenyl chlorodibismuthine (11) as an impurity were also isolated from the reaction mixture. Furthermore, Monoammonium salt [CpFe{2-(Me3N+CH2)C5H3}(BiPh2)2][I−] (6) and 1,1´,2-vinylferrocenyl dibismuthine derivative (7) were obtained by the reaction of CH3I with (3) and (1) respectively. The nucleophilic substitution reaction of (6) by o-hydroxyacetaphenone, salicylaldehyde, and N-methyl piperazine in acetonitrile gave the new functionalized 1,1′-2-substituted ferrocenyl dibismuthines [(C5H4)(BiPh2)]Fe[{2-(RCH2)C5H3}BiPh2] where R = OC6H4-2-C(O)Me (8), OC6H4-2-C(O)H (9) and N(CH2CH2)2NMe (10) respectively with different N or O containing pendant arm. 1,2-disubstituted ferrocenyl compounds presented in this work present planar chirality. These new compounds were characterized by IR, 1H-NMR, 13C-NMR spectroscopy, and High-Resolution Mass Spectrometry (HRMS). The X-ray structures of 1,1´,2-trisubstituted ferrocenyl dibismuthines (10) and (11) were determined. The molecular structure of (11) shows hypervalent Bi•••N bonding in the solid-state. The compound (11) has planar chirality, central chirality, and Bi center-chirality with pseudo-trigonal bipyramidal geometry (see-saw structure) around the chiral Bi center while the other bismuth atom has distorted trigonal pyramidal geometry. The variable temperature 1H-NMR spectra of compound (3) in −40°C to 40°C range in CDCl3 indicates a lack of Bi•••N coordination.