The Unconventional Nature of the Nematic Phase of Bent-Core Liquid Crystals Revealed by X-ray Diffraction

The great interest of liquid crystal (LC) scientists in the nematic (N) phase of bent-core mesogens originated in 2004, when two claims of biaxiality, based on nuclear magnetic resonance [1] and X-ray diffraction data [2], fueled an animated debate within the LC community. Indeed, nematic biaxiality is considered the Holy Grail of LC science, theoretically predicted in 1970, but never unequivocally proved in low molecular weight thermotropic liquid crystals [3,4]. At the same time, several studies pointed out other unique properties of bent-core nematics, such as their ferroelectric switching behavior [5,6], extraordinary sensitivity to external magnetic and electric field [7,8], and unconventional rheological properties [9].