New Liquid Crystalline Conjugated Derivatives of 3,3‘-Bipyridine as Components for Optoelectronic Materials

Abstract

We present a series of new 6,6‘-distyryl-3,3‘-bipyridine derivatives synthesized via a Knoevenagel condensation reaction and disubstituted with electron donor and acceptor groups. These molecules were characterized by spectroscopic methods (NMR, Raman, UV−vis, photoluminescence). These compounds were all found to exhibit thermotropic liquid crystalline (LC) phases, the structures of which were analyzed by DSC and temperature-dependent X-ray diffraction. The high degree of conjugation and the mesogenic character of these molecules could lead to nonlinear optical (NLO) applications for the “push−pull” compounds. Absorption in the UV range and blue fluorescence are other characteristics of some members of this group. The latter property opens up applications as light-emitting diodes (LEDs).

Symmetric and Asymmetric Conjugated 3,3′-Bipyridine Derivatives as a New Class of Third-Order NLO Chromophores with an Enhanced Non-resonant, Nonlinear Refractive Index in the Picosecond Range

“…A similar trend was also found for tetraethynylethenes [7b,16] and 3,3¢-bipyridine derivatives. [11,12] It should be noted that in these two cases, the push±push and push±pull compounds exhibited nearly identical k max values. Moreover, the influence of the D/A pair on the linear optical properties is also clearly seen.…”

“…The synthesis of 6,6¢-dimethyl-3,3¢-bipyridine (1) has previously been reported, [11] and 2,5-bis(decyloxy)benzene-1,4-dialdehyde was prepared by a modified literature procedure. [14] Symmetric chromophores (S1 and S2) were obtained in a one-pot reaction by reacting one mole of (1) with two moles of the appropriate aldehyde (Scheme 1a).…”

Star‐ and Banana‐Shaped Oligomers with a Pyrimidine Core: Synthesis and Light‐Emitting Properties

“…[8] The incorporation of a π-deficient heterocycle such as pyridine, [9] s-triazine, [10] pyrazine, [11] quinoxaline [12] or pyrimidine [13] in the centre of the backbone of such molecules leads to a significant enhancement of some of their physical properties such as mesomorphism, fluorescence and solvatochromism. If the arms of these oligomers are substituted by donor groups, fluorescence with internal charge transfer (ICT) or twisted internal charge transfer (TICT) excited states is expected with interesting solvatochromic properties.…”

Ultrafast nonresonant third-order optical nonlinearity of a conjugated 3,3′-bipyridine derivative from 1150 to 1600 nm

“…11, and a new synthetic route has been developed 12 by modifying the one reported in previous articles. 13 The molecule exhibits an apolar structure donor-acceptor-acceptor-donor ͑D-A-A-D͒, in which the 3,3Ј-bipyridine core acts as the acceptor group ͑A-A͒ and the donor group ͑D͒ is a thiophene ring. The absorption spectra of the material dissolved in dichloromethane in the visible and near-infrared wavelength range are shown in Fig.…”