A new N₂O₂-donor compartmental Schiff base ligand and its cadmium(II) complex: synthesis, mesogenic and photoluminescent properties

ABSTARCT

A new mesomorphic compartmental [N₂O₂] donor Schiff base ligand [H₂L] has been synthesized and one corresponding polymeric cadmium(II) complex of the type [Cd-L]_n {H₂L = 4,6-bis((E)-1-(octadecylimino)ethyl) benzene-1,3-diol} is prepared by direct reaction of metal ion with ligand. Both the ligand and its Cd-complex do exhibit mesomorphic properties. The IR spectrum of the ligand clearly reveals that the ligand acts as a bi-negative tetradentate donor through the two sets of phenolate oxygen and azomethine nitrogen. Mesomorphic behavior of these compounds are investigated with the help of polarizing optical microscopy (POM) and differential scanning calorimetry (DSC). The organization of the ligand and complex molecules in the mesophase are investigated by X-ray diffraction techniques. The Schiff base ligand and its Cd-complex shows plastic columnar mesophase (Col_p) at ∼82 and ∼86 °C, respectively. The polymeric Cd-complex is blue light emitter with a broad emission maximum at ∼475 nm on excitation at 380 nm.

Graphical Abstract

Keywords:

• Mesomorphic
• polymeric
• luminescent
• PXRD
• columnar

Acknowledgements

Authors gratefully acknowledge the instrumental facility provided under UGC-SAP and DST-FIST programme, New Delhi.

Additional information

Funding

HARP is thankful to the Council of Scientific and Industrial Research (CSIR), New Delhi, India for research fellowship (No.09/747(0006)/2011-EMR-I).