Novel Optical and Magnetic Bistability and Photoinduced Transition in a One-Dimensional Halogen-Bridged Binuclear Pt Complex

Abstract

In iodine-bridged binuclear Pt compounds, R(4)[Pt(2)(pop)(4)I]nH(2)O and R(')(2)[Pt(2)(pop)(4)I]nH(2)O (pop=P(2)O5H2-2), electronic structures on the PtPtI chains have been controlled between a diamagnetic charge-density-wave (CDW) state and a paramagnetic charge-polarization (CP) state by modification of the counterions (R, R') located between chains. In the R=(C2H5)2NH+2 compound, a pressure-induced CP to CDW transition with a drastic color change is identified. This transition is accompanied by a large hysteresis loop within which photoinduced transition between CDW and CP can be driven by selecting the excitation photon energy.

Novel Countercation in MMX-Type Mixed-Valence Chain Compound: Coexistence of Neutral and Protonated Amino Substituents

“…However, pop-type MMX chains are more attractive because it is easier to synthesize various derivatives by changing countercations. Moreover, the new electronic state [21], photo-induced phase transition [22] and vapor-induced reversible switching of the electronic state and the electrical conductivity [23][24][25][26] have been reported, recently. In order to achieve the higher electrical conductivity in pop-type MMX chains, the doping of hole or electron into 1D chain is a promising method, though no trials have succeeded.…”

Three‐Dimensionally Ordered CDW State in Quasi‐One‐Dimensional Iodo‐Bridged Dinuclear Platinum Mixed‐Valence Compounds, A4[Pt2I(pop)4]·nH2O (A = Aromatic Ammonium Cations)

“…[6] In the former, the Pt-Pt dimer units are coordinated by four dithioacetate (dta) derivatives forming lantern structures, and these units are bridged by iodide ions to form neutral linear chains. The latter compounds have the chemical formulae A 4 [Pt 2 -(pop) 4 [7] We have also reported vapochromic behavior in {NH 3 (CH 2 ) n NH 3 } 2 [Pt 2 I(pop) 4 ]· 4H 2 O, which was accompanied by a phase change between the CP and CDW state with an increase or decrease in the temperature. [8] If a three-dimensionally ordered CP state can be constructed it may be possible to develop multiswitching devices, which convert between the CP state (ferroelectric, second-order optical nonlinear effect, paramagnetic) and the CDW state (non-dielectric, third-order optical nonlinear effect, diamagnetic) depending on pressure and photo and/or temperature-induced effects.…”

Photo-Induced Phase Transition in an Electron–Lattice Correlated System –Future Role of a Time-Resolved X-ray Measurement for Materials Science–

“…27,28) Here, we review the effect of the magnetic field on the PIPT and phase separation dynamics observed for spin crossover complexes as a typical example. We also review our recent work on ultra-fast dynamics of PIPT in 1/4-filled molecular crystals observed at around room temperature.…”