naa a22 4500 510733573 CHVBK 20180411083001.0 cr unu---uuuuu 180411e20131101xx s 000 0 eng 10.1007/s12039-013-0531-6 doi (NATIONALLICENCE)springer-10.1007/s12039-013-0531-6 Synthesis, optical and thermal behaviour of palladium(II) complexes with 4-(4-alkoxy-2-hydroxybenzylideneamino)azobenzene [Elektronische Daten] [BOON-TECK HENG, GUAN-YEOW YEAP, DAISUKE TAKEUCHI] A series of new Pd(II) complexes derived from the reaction of palladium acetate with 4-(4-alkoxy-2-hydroxybenzylideneamino)azobenzene having the flexible terminal chain of OC n H2n + 1, in which n are even numbers ranging from 8 to 16, has been successfully synthesized. The physical measurement and spectroscopic techniques (FTIR and 1H-NMR) reveal that the Pd(II) complexes possess the Pd-N and Pd-O coordination modes in which the central Pd(II) adopts square-planar geometry. The observation under the polarized light shows that all the ligands and Pd(II) complexes exhibit enantiotropic mesophases. The ligands with n-octyloxy and n-decyloxy flexible chains exhibit the nematic (N) and smectic A (SmA) phases whilst the Pd(II) complexes show exclusive SmA phase. The SmA phase observed in Pd(II) complexes can be supported by the presence of focal conic fan-shaped texture with the presence of curved lines which are prominent during the cooling process. On the other hand, the comparison studies show that Pd(II) complexes possess exceptional higher phase transition temperatures as compared to the corresponding Cu(II) and Ni(II) complexes. Graphical Abstract A new series of Pd(II) complexes with azobenzene core have been synthesized and characterized. The ligands with n-octyloxy and n-decyloxy flexible chains exhibit the nematic (N) and smectic A (SmA) phases whilst the Pd(II) complexes show exclusive SmA phase. Comparison study shows that Pd(II) complexes have exceptional higher phase transition temperatures as compared to its counterparts of Cu(II) and Ni(II). Indian Academy of Sciences, 2013 Pd(II) complexes nationallicence smectic A nationallicence nematic nationallicence 1H-NMR nationallicence Cu(II) complexes nationallicence HENG BOON-TECK Liquid Crystal Research Laboratory, School of Chemical Sciences, Universiti Sains Malaysia, 11800, Minden, Penang, Malaysia aut YEAP GUAN-YEOW Liquid Crystal Research Laboratory, School of Chemical Sciences, Universiti Sains Malaysia, 11800, Minden, Penang, Malaysia aut TAKEUCHI DAISUKE Chemical Resources Laboratory (Mailbox R1-03), Tokyo Institute of Technology, 4259 Nagatsuta, Midori-ku, 226-8503, Yokohama, Japan aut Journal of Chemical Sciences Springer India 125/6(2013-11-01), 1435-1443 0974-3626 125:6<1435 2013 125 12039 https://doi.org/10.1007/s12039-013-0531-6 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s12039-013-0531-6 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- HENG BOON-TECK Liquid Crystal Research Laboratory, School of Chemical Sciences, Universiti Sains Malaysia, 11800, Minden, Penang, Malaysia aut NATIONALLICENCE 700 1- YEAP GUAN-YEOW Liquid Crystal Research Laboratory, School of Chemical Sciences, Universiti Sains Malaysia, 11800, Minden, Penang, Malaysia aut NATIONALLICENCE 700 1- TAKEUCHI DAISUKE Chemical Resources Laboratory (Mailbox R1-03), Tokyo Institute of Technology, 4259 Nagatsuta, Midori-ku, 226-8503, Yokohama, Japan aut NATIONALLICENCE 773 0- Journal of Chemical Sciences Springer India 125/6(2013-11-01), 1435-1443 0974-3626 125:6<1435 2013 125 12039 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer