Crystal structures determined for eight compounds R-C6H4-C6H4-COO-C6H4-R',
where R and R' are achiral, four with octyloxy and/or octyl chains and four
with a methyl or methoxy group at one end, are classified into three modes
. First is a smectic-like layer composed of parallel molecules with closely
arranged ester linkages; second is a layer comprising two crystallographic
ally independent molecules, among which the ester linkages are close. Compo
unds with an octyloxy chain take these modes. Thirdly, for molecules with a
lkyl chains, the ester linkages are far apart among the parallel molecules.
Melting and clearing points suggest stronger intermolecular interactions i
n the former two modes than in the last mode.