Premium
Multifunctional Lanthanide Complexes: Mesomorphism, Photoluminescence and Second Order NLO Property
Author(s) -
Chakrabarty Rupam,
Dutta Abhijit,
Roy Sushmita,
Das Gobinda,
LedouxRak Isabelle,
Mondal Paritosh,
Prasad Subbarao. K.,
Rao Doddamane S. S.,
Bhattacharjee Chira R.
Publication year - 2018
Publication title -
chemistryselect
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.437
H-Index - 34
ISSN - 2365-6549
DOI - 10.1002/slct.201801561
Subject(s) - lanthanide , mesophase , schiff base , ligand (biochemistry) , alkoxy group , crystallography , luminescence , chemistry , photoluminescence , imine , proton nmr , ion , materials science , stereochemistry , phase (matter) , organic chemistry , alkyl , biochemistry , receptor , optoelectronics , catalysis
A series of new mononuclear multifunctional lanthanide(III)‐Schiff base complexes have been synthesized and characterized by elemental analyses, FTIR, 1 H NMR and UV/Vis spectroscopy. Potentially tridentate, the Schiff‐base ligand is based on a ‘salicyldimine’ core with a long and flexible alkoxy group which coordinates to lanthanide ions in its zwitterionic form via the phenolic‐oxygen with the proton shifted to the imine‐nitrogen. The chelate nitrato groups complete a nine‐coordinate geometry. The ligand is non‐mesomorphic, while coordination to Ln 3+ ion induces a liquid crystalline behavior. The complexes exhibited a thermally stable highly viscous partially bilayer smectic A d phase in the 45‐135°C temperature range. The molecular organization of the complexes in the mesophase is conjectured to be based on a cylindrical‐like dimeric structure with the three alkoxy group pointing up and three pointing down assembling laterally into a lamellae. The Schiff base ligand is a blue light emitter exhibiting a broad emission maximum at 435 nm while the lanthanide complexes show an intense green emission. The Tb 3+ complex, interestingly, also showed mesophase luminescence. The ligand and its complexes of La 3+ , Dy 3+ and Yb 3+ exhibited a significant second order non‐linear optical (NLO) activity representing the first example of lanthanidomesogens to exhibit such behaviour.