1.
Angew Chem Int Ed Engl
; 39(14): 2495-2498, 2000 Jul 17.
Article
in English
| MEDLINE
| ID: mdl-10941115
2.
Angew Chem Int Ed Engl
; 38(23): 3474-3477, 1999 Dec 03.
Article
in English
| MEDLINE
| ID: mdl-10602212
ABSTRACT
A remarkably high specific rotation, even at 589 nm, is shown by (M)-1, the first enantiomerically pure unbranched [4]triangulane, although it has no chromophore that would lead to any significant absorption above 200 nm. This outstanding rotatory power is in line with a helical arrangement of its sigma bonds, as confirmed by high-level computations. Thus, it is appropriate to call (M)-1 a "sigma-[4]helicene", the first sigma-bond analogue of the aromatic [n]helicenes.