121882-79-9Relevant academic research and scientific papers
Synthesis, halogenolysis, and crystal structure of hypervalent organobismuth compounds (10-Bi-5)
Chen, Xiang,Ohdoi, Keisuke,Yamamoto, Yohsuke,Akiba, Kin-Ya
, p. 1857 - 1864 (2008/10/08)
The stable 10-Bi-5 compounds (o-C6H4C(CF3)2O)BiAr2R (3, (Ar, R): 3a, p-CH3C6H4,p-CH3C6H 4; 3b, p-CF3C6H4, p-CF3C6H4; 3c, p-FC6H4, p-FC6H4; 3d, p-CH3C6H4, p-CF3C6H4; 3e, p-CF3C6H4, p-CH3C6H4; 3f, p-CH3C6H4, PhC≡C; 3g, p-CH3C6H4, Me) were synthesized. The X-ray structures of 3a,f,g showed distorted-trigonal-bipyramidal geometries, and the electronegative apical PhC≡C ligand of 3f made the apical Bi-O bond (2.243(3) ?) shorter than the Bi-O bond of 3a,g (2.323(4) ? in 3a and 2.328(7) ? in 3g). Halogenolysis of 3 with sulfuryl chloride or pyridinium bromide perbromide gave the five-coordinate bismuth compounds (o-C6H4C(CF3)2O)BiAr 1-Ar2X(6 (Ar1,Ar2,X): 6a, p-CH3C6H4, p-CH3C6H4, Cl; 6b, p-CF3C6H4, p-CF3C6H4, Cl; 6c, p-FC6H4, p-FC6H4, Cl; 6d, p-CH3C6H4, p-CH3C6H4, Br; 6e, p-CH3C6H4, p-CF3C6H4, Cl; 6f, p-CH3C6H4, p-CF3C6H4, Br) in good to quantitative yield with apical covalent Bi-halogen bonds which were clearly shown by the X-ray analysis of 6a,b,d,e. The reactivity order of 3 for the halogenolysis was as follows: PhC≡C-Bi> Me-Bi> p-CH3C6H4-Bi> p-CF3C6H4-Bi. Direct halogenolysis of the bismuth-carbon bond was suggested. The variable-temperature 19F NMR of unsymmetrically substituted 6e,f did not show coalescence of the CF3 groups up to 170°C in a dilute solution of toluene-d8, and the energies of inversion at the bismuth atom should be higher than 21 kcal mol-1 at 170°C.
