Such molecular geometry promotes
bent conformers, in which two mesogenic units make an
average angle of 120 deg; it also ensures large flexibility
because of a low energy barrier for rotations around chemical
bonds within the spacer. Two basic molecular modifications
were applied for both series of compounds; the length (n) of
a terminal alkyl or alkoxy chain at the rod-like azo/imine unit
and the length of the flexible spacer (m) were changed. For
a fixed terminal chain (n=1), compounds show the N*-NTB*
phase transition, except for the azo compound with the
longest m=15 tail, for which the N*-SmA phase transition
was found (related DSC scans are presented in the Supporting
Information). Apparently changing the length of the inner