一种手性自旋交叉金属-有机框架材料.docVIP

  A Chiral Spin Crossover Metal-Organic Framework# LIU Wei1, BAO Xin1, MAO Lingling1, JIRI Tucek2, RADEK Zboril2, LIU Junliang1, 5 10 15 20 25 30 35 40 GUO Fusheng1, NI Zhaoping1, TONG Mingliang1** (1. School of Chemistry and Chemical Engineering, Sun Yat-Sen University, Guangzhou 510275; 2. Regional Centre of Advanced Technologies and Materials, Palacky University in Olomouc) Abstract: An unprecedented chiral metal-organic framework with spin crossover (SCO) property, [FeII(mptpy)2]?EtOH?0.2 DMF (1?nsolv), has been solvothermally synthesized through spontaneous resolution. It displays remarkable stability and two-step SCO under (Tc1 = 200 K) and above (Tc2 = 357 K) room temperature. Key words: metal-organic framework; chiral structure; spin-crossover; spontaneous resolution 0 Introduction As a consequence of the splitting of the energy of the d orbitals into t2g and eg sets in octahedral field, metal ions with configuration d4 to d7, particularly the FeII ion, can undergo SCO if appropriate ligand field strength is afforded. The switching between the high-spin (HS) and low-spin (LS) states may be driven by external stimuli such as temperature, pressure, light and magnetic field, resulting in alterable chemical and physical properties and thus offering potential applications as molecular switches, molecular sensors, data storage and display devices.1-6 Furthermore, developing SCO materials exhibiting multi-step spin transition around room temperature, which enables a larger information storage capacity, would be of great interest towards application. Particularly, the synthesis of new multi-functional materials is one of the most important trends in the SCO field, in which the SCO properties may be combined with other physical or chemical properties, such as magnetic coupling, liquid crystalline properties, non-linear optical properties and electrical conductivity.5-8 In order to obtain novel magneto-optical materials, integrating chirality into SCO complexes w