Complexes of some 4f metal ions of the mesogenic Schiff-base, N,N′-di-(4-decyloxysalicylidene)-1′,3′-diaminobenzene: synthesis and spectral studies

• Published in: Journal of coordination chemistry Vol. 65; no. 20; pp. 3519 - 3529
• Main Authors: Shakya, Pawan Raj, Singh, Angad Kumar, Rao, T.R.
• Format: Journal Article
• Language: English
• Published: Abingdon Taylor & Francis Group 20.10.2012; Taylor & Francis Ltd
• Subjects: Complexes; III; Infrared radiation; Mesogenic Schiff-base; Mono-capped octahedron; NMR and IR Spectra; Studies; Zwitterionic-coordination
• ISSN: 0095-8972; 1029-0389
• DOI: 10.1080/00958972.2012.719225

A mesogenic Schiff-base, N,N′-di-(4-decyloxysalicylidene)-1′,3′-diaminobenzene, H 2 ddsdbz (abbreviated as H 2 L), that exhibits a nematic mesophase was synthesized and its structure was studied by elemental analysis, mass spectrometry, NMR, and IR spectral techniques. The Schiff-base, H 2 L, upon condensation with hydrated lanthanide(III) nitrates yields Ln III complexes, [Ln 2 (LH 2 ) 3 (NO 3 ) 4 ](NO 3 ) 2 , where Ln = La, Pr, Nd, Sm, Eu, Gd, Tb, Dy, and Ho. Analyses of the IR and NMR spectral data imply bidentate Schiff-base through two phenolate oxygen atoms in its zwitterionic form to Ln III , rendering the overall geometry of the complexes as a seven-coordinate polyhedron - possibly distorted mono-capped octahedron. Polarizing optical microscope and differential scanning calorimetry studies reveal that despite H 2 L being mesogenic, none of the Ln III complexes synthesized under this study exhibits mesomorphism.