Effect of Substitution on the Hysteretic Phase Transition in a Bistable Phenalenyl‐Based Neutral Radical Molecular Conductor

Abstract

The ability to tune the physical properties of bistable organic functional materials by means of chemistry can facilitate their development for molecular electronic switching components. The butylamine‐containing biphenalenyl boron neutral radical, [Bu]2B, crystalline compound has recently attracted significant attention by displaying a hysteretic phase transition accompanied by simultaneous bistability in magnetic, electrical, and optical properties close to room temperature. In this report, substitutional doping was applied to [Bu]2B by crystallizing solid solutions of bistable [Bu]2B and its non‐radical‐containing counterpart [Bu]2Be. With increasing doping degree, the hysteretic phase transition is gradually suppressed in terms of reducing the height, but conserves the width of the hysteresis loop as observed through magnetic susceptibility and electrical conductivity measurements. At the critical doping level of about 6 %, the abrupt transformation of the crystal structure to that of the pure [Bu]2Be crystal packing was observed, accompanied by a complete collapse of the hysteresis loop. Further study of the structure–properties relationships of bistable neutral radical conductors based on the [Bu]2B host can be conducted utilizing a variety of biphenalenyl‐based molecular conductors.

Synthesis and Physical Properties of Trioxotriangulene Having Methoxy and Hydroxy Groups at α-Positions: Electronic and Steric Effects of Substituent Groups and Intramolecular Hydrogen Bonds

“…We are also interested in stimuli-response properties of 2b based on the dynamics of protons within the intramolecular H bonds as observed in 9-hydroxyphenalenone derivatives ,. Furthermore, inspired by pioneering studies on the catalytic activity of metal complexes and the high electrical conductivity of a single component of open-shell boron complexes derived from 9-hydroxyphenalenone derivatives, our current research is also aiming to synthesize metal complexes of 2b utilizing the OH and oxo groups as chelating ligands. These materials will extend to multidimensional aggregates such as metal–organic framework (MOF) and covalent organic framework (COF), including TOT , and are expected to provide an opportunity for exploring intriguing functional materials.…”

FeIII, CuII and ZnII Complexes of the Rigid 9-Oxido-phenalenone Ligand—Spectroscopy, Electrochemistry, and Cytotoxic Properties

“…The resulting species is best described as [Cu I (opo − ) 2 ] •− . A contribution of the resonance form [Cu II (opo •2− )(opo − )] •− can be ruled out as a species containing opo •2− is characterised by intense dark colours in the visible range of the spectrum [45][46][47][48][49][50]52,54,55,57].…”

“…Upon reduction at −2 V corresponding to the potential of the first reduction wave observed in the CV, the sharp 339 band and the structured absorption centred at 460 nm disappeared and broad bands at 420 and 630 nm grew in (Figure S11, Supplementary Materials). We assigned these bands to typical transitions involving a reduced opo •2− ligand [45][46][47][48][49][50]52,54,55,57] and describe the complex as [Zn II (opo •2− )(opo − )] •− . (dach = 1,2-diaminocyclohexane) was found to be active against an A549 human lung cancer cell line with activities two times higher than oxaliplatin [31].…”

“…In complexes of non-innocent ligands, the ligands can have variable charges and oxidation states, thus making the metal oxidation state ambiguous [18]. Opo complexes of main-group and transition metals are therefore intensely studied for their magnetic, electron-and chargetransfer phenomena [44][45][46][47][48][49][50][51][52][53][54][55] as well as for their use in electroactive materials [51][52][53][54][55][56][57][58][59] or in electron transfer or related catalysis [53,55,57,[60][61][62][63][64][65][66][67][68][69][70].…”