Enhancement of smectic C mesophase stability by using branched alkyl chains in the auxiliary ligands of luminescent Pt(II) and Pd(II) complexes

Monica Iliş, Marin Micutz, Florea Dumitraşcu, Iuliana Pasuk, Yann Molard, Thierry Roisnel, Viorel Cîrcu
2014 Polyhedron  
A novel series of Pd(II) and Pt(II) complexes based on cyclometalated imine ligands and N-benzoylthiourea (BTU) derivatives as auxiliary ligands has been prepared and their liquid crystalline properties as well as photophysical properties have been investigated. The crystal structure of one cyclometalated Pt(II) complex with N-(p-Fphenyl)-N'-benzoylthiourea as co-ligand has been solved. The liquid crystalline properties have been investigated by a combination of DSC, POM and variable
more » ... powder X-ray diffraction. These new metallomesogens display either a monotropic SmC phase or both SmA and SmC phases depending on the number of alkoxy groups attached to the imine ligand, alkyl chain length or the use of branched alkoxy terminal groups. We found that the introduction of branched alkoxy terminal groups lead to lower transition temperatures and stabilisation of the SmC phase in both Pd(II) and Pt(II) complexes. While the Pd(II) complexes display no emission, the Pt(II) complexes show good emission properties in solution, solid state and PMMA film at room temperature and their investigation is reported.
doi:10.1016/j.poly.2013.11.015 fatcat:lkj55376wveklij5fgtaepwv4m