Novel Green Light Emitting Nondiscoid Liquid Crystalline Zinc(II) Schiff‐Base Complexes

Abstract

A new series of nondisc-like Zn II Schiff base complexes of the type [Zn (4-C n H 2n+1 O) 2 salophen], n = 14, 16, 18, salophen = N,NЈ-phenylenebis(salicylideneiminato), have been prepared and their mesogenic, photophysical properties investigated. The mesomorphic behaviour of these compounds was studied by differential scanning calorimetry, polarized optical microscopy and X-ray diffraction (XRD) techniques. The ligands are found to be nonmesogenic, but their complexes exhibited a columnar mesomorphism. The XRD-study re-

Influence of spacer group substituent on mesomorphism in copper complexes of ‘salen’ type Schiff bases bearing long alkoxy arm

“…[42] As for zinc, the complexes, Zn-16opd and Zn-16mpd were earlier shown to exhibit rectangular and hexagonal columnar mesomorphism, respectively. [37,38] Other than the oxovanadium complex which is square pyramidal, rest all complexes reported previously by us and the present copper complexes possess distorted square planar structure. While we obtained predominantly columnar phases (rectangular columnar Col r , rectangular plastic columnar Col rp , hexagonal columnar Col h, oblique columnar Col o , lamello columnar Col L ) in all structures, no specific trend was noticed regarding the nature of the phases.…”

“…[3][4][5][6]35,36] Recently, a variety of structurally analogous 4-substituted zinc(II), oxovanadium(IV), nickel(II) using phenylene/cyclohexane diamine spacer exhibiting different types of columnar phases have been reported by us. [37][38][39][40][41][42][43][44] Quite surprisingly, liquid crystalline copper(II)-salen complexes bearing aromatic spacer, affording columnar mesophases have not yet been reported. Pertinent here is to mention that copper (II) complexes with cyclohexane diamine spacer have been reported to show rectangular columnar mesophase.…”

“…Pertinent here is to mention that copper (II) complexes with cyclohexane diamine spacer have been reported to show rectangular columnar mesophase. [39] Set in this backdrop we embarked on the synthesis of copper(II) complexes of 'salen' type Schiff base ligand with different substituent on aromatic spacer group and explore their mesomorphic behaviour and collate with related reported [37][38][39][40][41][42][43][44] ligand systems with different divalent metal ions.…”

Liquid-crystalline oxovanadium(IV) complexes accessed from bidentate [N, O] donor salicylaldimine Schiff-base ligands

“…In the past few years, a wide variety of metallomesogens has been synthesized based on salicylaldimine ligands [31][32][33][34][35][36][37][38][39][40][41]. First reports on mesogenic vanadyl complexes with salicylaldimine ligands were made by Galyametdinov et al [42].…”

Photoluminescent columnar zinc(II) bimetallomesogen of tridentate [ONO]-donor Schiff base ligand

“…[12][13][14][15] In this context, comprehensive research effort has been invested from our group recently in the design of metalcontaining LCs with the aim of combining the unique properties of anisotropic fluids with the specific luminescent properties. [16][17][18][19][20] The molecular shape has a dominant control on the mesomorphic behaviour. A number of mononuclear salicylaldimine complexes have been documented; [21][22][23] however, very few examples of bi-metallomesogen are reported so far.…”