Dynamics and the mesomorphic properties of a novel antiferroelectric liquid crystalline thiobenzoate MHPSBO10: thermal, optical and dielectric spectroscopy study.
The complementary studies of the mesomorphic properties of a novel antiferroelectric liquid crystal (AFLC) (S)-2-octile 4-S-(4'decyloxybiphenyl-4-tiocarboxy)benzoate, known under MHPSBO10 acronym have been undertaken. The polymorphism has been complementary studied in details by Differential Scanning Calorimetry (DSC), Transmitted Light Intensity (TLI) and Polarization Microscopy (POM). The switching characteristics along with multiple macroscopic parameters describing the mesomorphic properties were determined by using electro-optic measurements, both upon cooling and heating. Frequency domain dielectric spectroscopy (DS), covering a wide frequency range, has been applied to characterize the molecular motions. Several collective modes, including the low frequency processes in the condensed hexatic phase were detected, analyzed in details and followed with the temperature. The presented studies deliver a wide report of the phase transitions, molecular dynamics and the macroscopic properties of the novel antiferroelectric thiobenzoate.
Phase transitions of new antiferroelectric thiobenzoate
This article reports on the phase sequences in a new chiral liquid crystalline compound, a member of the thioester series, (S)-(+)-4-[(4-{[1-methyl]heptylcarboxyl}phenyl)-carbonylthio]phenyl-4′-decyloxy-1-benzencarboxylate, referred to as 10.OPOSMH, which has been recently synthesized. 10.OPOSMH exhibits ferro- and antiferroelectric behaviour. This compound contains three benzene rings connected with the ester and thioester central groups. The 10.OPOSMH molecule is terminated with the achiral n-decyloxy and chiral (S)-(+)-1-methylheptyl carboxylate terminal chains, where the chiral group is in para position with respect to the thioester group. This mesogen assumes the existence of antiferroelectric smectic C ( ) and ferroelectric smectic C ( ) phases and also the smectic chiral subphases: , and , both on heating and cooling. †This article is dedicated to Prof. Dr Jerzy A. Janik on his 80th birthday.
Luminescence Phenomena Involving Metal Enolates
1 
Introduction 
 
2 
Metal Enolates 
 
3 
Luminescence of Rare-Earth Enolates 
 
4 
Luminescence Involving s, p and d Metal Block Enolates 
 
5 
Applications 
 
6 
Acknowledgments 
 
 
 
Keywords: 
 
luminescence phenomena involving metal enolates; 
chemistry of metal β-diketonate complexes; 
luminescence of rare-earth enolates; 
photoluminescence of rare-earth β-diketonates; 
diketonate ligand–rare-earth ion energy transfer rates; 
luminescence involving s, p and d metal block enolates; 
photoluminescence of d-transition metal enolates; 
applications - time-resolved detection of luminescence for bioassays