Chiral molecular propeller conformations have been induced to various triaryl structures including trityl derivatives and triaryl boranes. For borane-amine adducts, such induced propeller chirality has not been reported yet due to the low energy barrier for racemization in typical triarylboranes such as B(C 6 H 5) 3 or B(C 6 F 5) 3. Herein we demonstrate that point-chirality in side chains of chiral triarylborane-ammonia adducts, that feature intramolecular hydrogen bonds in addition to the dative N→B bond, can efficiently be transferred to triarylborane propeller chirality. Employing X-ray crystallography and both electronic and vibrational circular dichroism (ECD/VCD) spectroscopy for structural characterizations, we investigate three examples with different steric demands of the incorporated chiral alkoxyl side groups. We elucidate the conformational preferences of the molecular propellers. Furthermore, we show that computationally predicted conformational preferences obtained for the isolated, only implicitly solvated molecules are actually opposite to the experimentally observed ones.

We report the IR and VCD spectra of azithromycin, a macrolide antibiotic with a total of 18 stereogenic centers. The computational analysis of the spectra reveals that a single water...

Texture transformations in reactive metal films deposited upon amorphous substratesFilms of titanium silicide were deposited on oxidized silicon wafers by means of the coevaporation of titanium and silicon. The atomic concentration range 0

Stabilization of chiral propeller conformations in triaryl compounds is challenging due to generally low racemization barriers. Nonetheless, it was recently found that chiral conformational preferences can be induced to triaryl boranes by incorporating point‐chiral alkylether chains to the aryl blades and subsequently locking the structure with ammonia. A four‐point interaction, meaning that the cooperative effects of Lewis‐adduct formation and three hydrogen bonds, was proposed as stabilizing mechanism. Herein, it was shown that three such strong interactions suffice to introduce a preferential propeller handedness. Although DFT calculations predict no noteworthy preferences for either P‐ or M‐chiral propellers for some of the investigated triarylborane–amine adducts that were prepared with chiral primary amines, vibrational circular dichroism (VCD) spectroscopic characterizations revealed that there is indeed a measurable excess of one propeller handedness. Furthermore, the steric demand of the amine was found to play a key role in the induction process and especially in preventing blade rotations.