Green-blue light-emitting platinum(ii) complexes of cyclometallated 4,6-difluoro-1,3-dipyridylbenzenes showing mesophase organisation

Abstract

Blue-green light-emitting phosphorescent PtII complexes of 1,3-bis(2-pyridyl)benzene are reported that incorporate hexadecyl-containing fragments in the 5-position of the pyridine rings.

Synthesis, mesomorphism, photophysics and device performance of liquid-crystalline pincer complexes of gold(iii)

“…Luminescent metallomesogens, which combine the properties of self-organisation and emissive behaviour, have potential applications in the field of semiconductors and are known in the literature. 1 Most of these studies have been based on complexes of platinum(II), [2][3][4][5][6] which is amenable to liquid crystal phase formation on the basis of its square-planar geometry, but there have also been reports based on, for example, gallium(III), 7 zinc(II), 8,9 silver(I), 10 various lanthanides 11 and iridium(III), [12][13][14][15][16][17] the last two of which are somewhat more challenging given the 3D, octahedral nature of the metal centre. One attraction of phosphorescent metallomesogens relates to taking advantage of the long-range order possible in liquid crystal systems to generate ordered conduction layers, so potentially reducing drive voltages.…”

An overview of phosphorescent metallomesogens based on platinum and iridium

“…78 To this end, Kozhevnikov et al designed platinum-based, luminescent metallomesogens 20-23 ( Figure 17) based on NCN ligands. 79,80 Most of the complexes reported contained a 3,4,5-trialkoxyphenyl fragment, some also with a fused cyclopentylene ring, which was found to affect the mesophase shown and the mesophase stability so that complex 20 showed a Colr phase, while 21 showed a Colh phase with a higher clearing point. 79 The complexes had relatively low emission efficiencies (0.07 and 0.12, respectively), but an interesting observation was that the emission wavelength for complexes 20 depended on thermal and mechanical history (Figure 18).…”

“…In order to further explore the structure-property relationship, the same group introduced fluorines into the central phenyl ring (22) and then by using trialkoxybenzoyl esters to introduce the terminal chains (23). 80 Although they are analogous structurally with 20 and 21, both the mesophase and emission properties were different. Thus, complex 22 showed a mesophase that had a monoclinic space group in the lower-temperature phase while a P6/mm lattice was observed in the higher-temperature phase.…”

Tuning the Aggregation of N^N^C Pt(II) Complexes by Varying the Aliphatic Side Chain and Auxiliary Halide Ligand: 1H and 195Pt NMR Investigation

“…Aggregation and self ‐organisation of square planar Pt(II) complexes is a widely used tool in supramolecular chemistry Driven by a variety of intermolecular forces, including metallophilic Pt–Pt interactions, many supramolecular architectures such as gels,, liquid crystals and polymers have been prepared. To study self‐aggregation is an important task because the properties of the aggregates are often very different to the ones of individual molecules.…”