Chromic Behaviors of Hexagonal Columnar Liquid Crystalline Platinum Complexes with Catecholato, 2-Thiophenolato, and Benzenedithiolato

Abstract

Liquid crystalline (LC) platinum(II) complexes with 1,2-thiophenolato and 1,2-benzendithiolato have been newly synthesized and investigated by spectroscopy together with the catecholato analogue. The variations in coordinating atoms (O or S or O/S mixed) lead to significant modulation in electrochemical properties in solution and absorption and emission properties of the complexes both in solution media and in the condensed phases. The asymmetric, polar mesogens/chromophores consisting of Pt(II), redox-active ligands, and alkyl-substituted bipyridine commonly play important roles not only in stabilizing the columnar LC phases, but also in fluctuations of the ground state energies. A key finding of the present work is the chromic properties of LC complexes induced by the interplay of self-association of the mesogens/chromophores and their fluctuating properties.

Ambipolar Discotic Liquid Crystals Built Around Platinum Diimine‐Dithiolene Cores

“…Surprisingly, to our knowledge, only one liquid crystalline material build around a metal diimine‐dithiolene core has been described to date . Ho‐Chol Chang and co‐workers described in 2011 that a platinum complex having an asymmetric molecular structure derived from 1,2‐benzenedithiolato (bdt) and a bipyridine ligand carrying ramified C8 or C10 carbon chains, forms a columnar mesophase of hexagonal symmetry over a large temperature range from −18 °C up to 194 °C.…”

(Photo)Thermal Stimulation of Functional Dithiolene Complexes in Soft Matter

“…In fact, platinum diimine‐dithiolene complexes displaying liquid crystalline properties have been isolated using functional bipyridines. The first liquid crystalline material build around a metal diimine‐dithiolene core has been described by Ho‐Chol Chang and co‐workers in 2011 (Figure a) . A platinum complex having an asymmetric molecular structure derived from 1,2‐benzenedithiolato (bdt) and a bipyridine ligand carrying ramified C13(8) carbon chains forms a columnar mesophase of hexagonal symmetry over a large temperature range from –18 °C up to 194 °C.…”

Coordination Programming: A New Concept for the Creation of Multifunctional Molecular Systems

“…This hypothesis was experimentally demonstrated in an ionic DA chain synthesized from a redoxactive paddlewheel [ Figure 8). 20 Liquid crystals were combined with platinum(II) complexes containing 1,2-thiophenolato and 1,2-benzenedithiolato ligands by Chang et al 21 The variations in the coordinating atoms led to significant modulation of the electrochemical properties in solution and also of the absorption and emission properties of the complexes both in solution and in the condensed phase.…”