A statistical study between ‘Mesophase Lower Transition Temperatures’
(MLTTs) and their structural properties is carried out to understand the effect of structural
behaviour on mesomorphic property.
Introduction: To establish a “Quantitative Structure and Property Relationship (QSPR)
model” a set of randomly selected thirty-nine mesomorphic compounds is constructed. The
backward stepwise regression analysis method is used to find out the good correlation between
the “Mesophase Lower Transition Temperatures (MLTTs)” data set and “physical
descriptors” like AMR, bpol, ASP-0, DELS, SdssC, etc. Physical descriptors are selected
based on their good r2-values and p-values with respective MLTTs. The derived QSPR equation
shows a good correlation between structural properties and mesomorphic properties of
Methods: Validation of the derived QSPR equation is carried out on the test series of eight
compounds. The MLTTs of these compounds are predicted through the statistically derived
QSPR equation and then compared with experimentally measured MLTTs. The average percentage
error observed between predicted MLTTs and experimentally measured MLTTs is
10.95 % for all the thirty-nine compounds of the trial set and 10.64% for 8 compounds of the
test series, respectively.
Results & Discussion: A low average percentage error suggests a reasonably acceptable
degree of accuracy of the generated QSPR model to predict MLTTs of the compounds having
a similar type of structure. In the present study, not only MLTTs are predicted, but an
effort is also made to predict “Latent Transition Temperatures” (LTTs) of some nonmesomorphic
compounds from the derived QSPR equation.
Conclusion: This computational study gives an insight into developing new QSPR models
for the different type of liquid crystals homologous series, through which various types of
mesomorphic properties, like mesomorphic thermal stability, mesomorphic upper transition
temperature, mesophase length, phase behaviour, etc. can study and predict.