Potential photoacid generators based on oxime sulfonates

We are grateful to the National Mass Spectrometry Foundation, University of Swansea, and to the National Crystallographic Service Center, University of Southampton.Peer reviewedPostprin

Heliconical smectic phases formed by achiral molecules

M.S. acknowledges the support of the US National Science Foundation I2CAM International Materials Institute Award, Grant DMR-1411344 and NSF grant DMR-1307674. D.P., E.G. acknowledges the support of the National Science Centre (Poland) under the grant no. 2016/22/A/ST5/00319. R.W. gratefully acknowledges the Carnegie Trust for the Universities of Scotland for the award of a PhD studentship. The beamline 11.0.1.2 at the Advanced Light Source at the Lawrence Berkeley National Laboratory is supported by the Director of the Office of Science, Office of Basic Energy Sciences, of the U.S. Department of Energy under Contract No. DE-AC02- 05CH11231. Addendum: Heliconical smectic phases formed by achiral molecules Published: 17 July 2018, https://doi.org/10.1038/s41467-018-05334-x "We would like to make our readers aware of the related publications by S.P. Sreenilayam et al. (Nat. Commun. 7, 11369 (2016) and Phys. Rev. Mat. 1, 035604 (2017)), which report the spontaneous helix formation in a polar smectic liquid crystal phase made of achiral bent-core mesogens."Peer reviewedPublisher PD

Heliconical smectic phases formed by achiral molecules.

Chiral symmetry breaking in soft matter is a hot topic of current research. Recently, such a phenomenon was found in a fluidic phase showing orientational order of molecules-the nematic phase; although built of achiral molecules, the phase can exhibit structural chirality-average molecular direction follows a short-pitch helix. Here, we report a series of achiral asymmetric dimers with an odd number of atoms in the spacer, which form twisted structures in nematic as well as in lamellar phases. The tight pitch heliconical nematic (NTB) phase and heliconical tilted smectic C (SmCTB) phase are formed. The formation of a variety of helical structures is accompanied by a gradual freezing of molecular rotation. In the lowest temperature smectic phase, HexI, the twist is expressed through the formation of hierarchical structure: nanoscale helices and mesoscopic helical filaments. The short-pitch helical structure in the smectic phases is confirmed by resonant X-ray measurements