Stimulus-responsive metal-organic frameworks(MOFs)can be used for designing smart materials.Herein,we report a family of rationally designed MOFs which exhibit photoresponsive chiroptical and magnetic properties at ro...Stimulus-responsive metal-organic frameworks(MOFs)can be used for designing smart materials.Herein,we report a family of rationally designed MOFs which exhibit photoresponsive chiroptical and magnetic properties at room temperature.In this design,two specific nonphotochromic ligands are selected to construct enantiomeric MOFs,{Cu_(2)(L-mal)_(2)(bpy)_(2)(H_(2)O)·3H_(2)O}n(1)and{Cu_(2)(D-mal)_(2)(bpy)_(2)(H_(2)O)·3H_(2)O}_(n)(2)(mal=malate,bpy=4,4’−bipyridine),which can alter their color,magnetism,and chiroptics concurrently in response to light.Upon UV or visible light irradiation,long-lived bpy−radicals are generated via photoinduced electron transfer(PET)from oxygen atoms of carboxylates and hydroxyl of malates to bpy ligands,giving rise to a 23.7%increase of magnetic susceptibility at room temperature.The participation of the chromophores(-OH and-COO^(−))bound with the chiral carbon during the electron transfer process results in a small dipolar transition;thus,the Cotton effects of the enantiomers are weakened along with a photoinduced color change.This work demonstrates that the simultaneous responses of chirality,optics,and magnetism can be achieved in a single compound at room temperature and may open up a new pathway for designing chiral stimuli-responsive materials.展开更多
The self-assembly of polyalcohol ligand 1,1,1-tris（hydroxymethyl）ethane with Dy（NO3）3· 6H2 O and Cr3O-Bzo-t-Bu precursor in the presence of triethylamine step-by-step generated a heterometallic 3d–4f chain. ...The self-assembly of polyalcohol ligand 1,1,1-tris（hydroxymethyl）ethane with Dy（NO3）3· 6H2 O and Cr3O-Bzo-t-Bu precursor in the presence of triethylamine step-by-step generated a heterometallic 3d–4f chain. Magnetic investigation of the complex indicates typical slow relaxation of the magnetization at low temperature.展开更多
基金support by the National Natural Science Foundation of China(Nos.91856124,22035003,21771111,and 21973038)the Programme of Introducing Talents of Discipline to Universities(B18030).
文摘Stimulus-responsive metal-organic frameworks(MOFs)can be used for designing smart materials.Herein,we report a family of rationally designed MOFs which exhibit photoresponsive chiroptical and magnetic properties at room temperature.In this design,two specific nonphotochromic ligands are selected to construct enantiomeric MOFs,{Cu_(2)(L-mal)_(2)(bpy)_(2)(H_(2)O)·3H_(2)O}n(1)and{Cu_(2)(D-mal)_(2)(bpy)_(2)(H_(2)O)·3H_(2)O}_(n)(2)(mal=malate,bpy=4,4’−bipyridine),which can alter their color,magnetism,and chiroptics concurrently in response to light.Upon UV or visible light irradiation,long-lived bpy−radicals are generated via photoinduced electron transfer(PET)from oxygen atoms of carboxylates and hydroxyl of malates to bpy ligands,giving rise to a 23.7%increase of magnetic susceptibility at room temperature.The participation of the chromophores(-OH and-COO^(−))bound with the chiral carbon during the electron transfer process results in a small dipolar transition;thus,the Cotton effects of the enantiomers are weakened along with a photoinduced color change.This work demonstrates that the simultaneous responses of chirality,optics,and magnetism can be achieved in a single compound at room temperature and may open up a new pathway for designing chiral stimuli-responsive materials.
基金supported by the NSF of China(Nos.21031002,21421001)Natural Science Fund of Tianjin,China(No.15JCZDJC38800)
文摘The self-assembly of polyalcohol ligand 1,1,1-tris（hydroxymethyl）ethane with Dy（NO3）3· 6H2 O and Cr3O-Bzo-t-Bu precursor in the presence of triethylamine step-by-step generated a heterometallic 3d–4f chain. Magnetic investigation of the complex indicates typical slow relaxation of the magnetization at low temperature.
