The change of fluorescence emission manipulated by spin state transition attracts considerable attention owing to its potential applications in magneto-optical switching devices.Herein,we report two two-dimensional(2D...The change of fluorescence emission manipulated by spin state transition attracts considerable attention owing to its potential applications in magneto-optical switching devices.Herein,we report two two-dimensional(2D)Hofmann-type spin crossover(SCO)metal-organic frameworks(MOFs)[Fe^(Ⅱ)(PNI)_(2){Ag^(Ⅰ)(CN)_(2)}_(2)]·CHCl_(3)(3Ag·CHCl_(3))and[FeⅡ(PNI)_(2){AuⅠ(CN)_(2)}_(2)]·CHCl_(3)(3Au·CHCl_(3))based on the fluorescent ligand N-(4-pyridylmethyl)-1,8-naphthalimide(PNI).Both complexes exhibit interesting SCO behaviors switched by vip solvent molecules,namely three-step transitions for the solvated complexes and complete onestep hysteretic SCO for the desolvated ones,verified by temperature-dependent magnetic susceptibility measurements,Mossbauer spectra,structural analyses,and differential scanning calorimetry measurements.Correspondingly,temperature-dependent fluorescence spectra exhibit double peaks(monomer and excimer emission)with both emission peaks change consistent with the change in SCO properties during the solvent molecule removal.In this study,we integrated vip-responsive SCO behavior into MOFs to manipulate the multistability of spin state and fluorescence switching,providing a rational strategy for the development of stimuli-responsive multifunctional materials.展开更多
Spin-crossover(SCO)complexes with multiple spin states are promising candidates for high-order magnetic storage and multiple switches.Here,by employing the N,N'-4-dipyridyloxalamide(dpo)ligand,we synthesize two Ho...Spin-crossover(SCO)complexes with multiple spin states are promising candidates for high-order magnetic storage and multiple switches.Here,by employing the N,N'-4-dipyridyloxalamide(dpo)ligand,we synthesize two Hofmann-type metal-organic frameworks(MOFs)[Fe(dpo){Ag(CN)_(2)}_(2)]·3DMF(1)and[Fe(dpo){Ag(CN)_(2)}_(2)]·0.5MeCN·2DEF(2),which exhibit vip dependent four-step SCO behaviors with the sequences of LS→~LS_(2/3)HS_(1/3)→LS_(1/2)HS_(1/2)→~LS_(3/10)HS_(7/10)→HS and LS→~LS_(2/3)HS_(1/3)→LS_(1/2)HS_(1/2)→~LS_(1/4)HS_(3/4)→HS,respectively.Therefore,the incorporation of hydrogen-donating/hydrogen-accepting groups into the Hofmann-type MOFs may effectively explore the multi-step SCO materials by tuning hydrogen-bonding interactions.展开更多
A two-dimensional cyanide-bridged Cu(Ⅱ)-Pt(Ⅱ) bimetallic complex has been synthesized by solution diffusion method using [Pt (CN)4]2- and [Cu (L)]2+ (L =3,10-diethanol-1,3,5,8,10,12-hexaazacyclotetradecane) as build...A two-dimensional cyanide-bridged Cu(Ⅱ)-Pt(Ⅱ) bimetallic complex has been synthesized by solution diffusion method using [Pt (CN)4]2- and [Cu (L)]2+ (L =3,10-diethanol-1,3,5,8,10,12-hexaazacyclotetradecane) as building blocks. Unexpectedly, the obtained complex Cu(DMF)2[Pt(CN)4] (1) is an analogue of the well-known Hofmann -type clathrate without macrocyclic ligand. Single-crystal X-ray diffraction reveals that 1 crystallizes in monoclinic, space group C2/m, a=1.624 8(6) nm, b=0.739 3(3) nm, c=0.695 5(3) nm, β=108.969(4)°. The crystal structure of 1 consists of two-dimensional corrugated metal cyanide sheets without interpenetration stacking along the a axis in an ABAB packing mode.展开更多
Herein,we report the first example showing the reversible on-off switching of spin-crossover(SCO)property by solid state photochemical[2+2]reaction.The ultraviolet(UV)light-induced[2+2]cycloaddition reaction of 3-spy ...Herein,we report the first example showing the reversible on-off switching of spin-crossover(SCO)property by solid state photochemical[2+2]reaction.The ultraviolet(UV)light-induced[2+2]cycloaddition reaction of 3-spy ligands in a twodimensional(2D)Hofmann-type framework[Fe(3-spy)_(2){Pd(CN)_(4)}](1,3-spy=3-styrylpyridine),which shows a hysteretic twostep SCO behavior,gives a 3D Hofmann-type framework[Fe(rctt-3-ppcb){Pd(CN)_(4)}](2,rctt-3-ppcb=rctt-1,3-bis(3-pyridyl)-2,4-bis(phenyl)cyclobutane,r=reference group,c=cis and t=trans)accompanied with the disappearing of SCO properties.Moreover,upon heating at 250℃ for 12 h,the rctt-3-ppcb ligand in 2 could be partially dedimerized to 3-spy with 68%completion through single-crystal-to-single-crystal(SCSC)transformation,giving the annealing complexes[Fe(3-spy)1.36(rctt-3-ppcb)0.32{Pd(CN)_(4)}](3)which display an incomplete SCO behavior.The 2■3 interconversion is successfully achieved via continuous UV irradiation and thermal annealing,demonstrating the effectiveness of photochemical[2+2]reaction on switching on-off SCO properties.展开更多
基金supported by the National Natural Science Foundation of China(22271171,21971142,and 22371015)Japan Society for Promotion Science(JSPS)KAKENHI(24K17698 and 24H00466)。
文摘The change of fluorescence emission manipulated by spin state transition attracts considerable attention owing to its potential applications in magneto-optical switching devices.Herein,we report two two-dimensional(2D)Hofmann-type spin crossover(SCO)metal-organic frameworks(MOFs)[Fe^(Ⅱ)(PNI)_(2){Ag^(Ⅰ)(CN)_(2)}_(2)]·CHCl_(3)(3Ag·CHCl_(3))and[FeⅡ(PNI)_(2){AuⅠ(CN)_(2)}_(2)]·CHCl_(3)(3Au·CHCl_(3))based on the fluorescent ligand N-(4-pyridylmethyl)-1,8-naphthalimide(PNI).Both complexes exhibit interesting SCO behaviors switched by vip solvent molecules,namely three-step transitions for the solvated complexes and complete onestep hysteretic SCO for the desolvated ones,verified by temperature-dependent magnetic susceptibility measurements,Mossbauer spectra,structural analyses,and differential scanning calorimetry measurements.Correspondingly,temperature-dependent fluorescence spectra exhibit double peaks(monomer and excimer emission)with both emission peaks change consistent with the change in SCO properties during the solvent molecule removal.In this study,we integrated vip-responsive SCO behavior into MOFs to manipulate the multistability of spin state and fluorescence switching,providing a rational strategy for the development of stimuli-responsive multifunctional materials.
基金supported by the National Key Research and Development Program of China(No.2018YFA0306001)the National Natural Science Foundation of China(Nos.21950410521,21771200and 21773316)the Pearl River Talent Plan of Guangdong(No.2017BT01C161)。
文摘Spin-crossover(SCO)complexes with multiple spin states are promising candidates for high-order magnetic storage and multiple switches.Here,by employing the N,N'-4-dipyridyloxalamide(dpo)ligand,we synthesize two Hofmann-type metal-organic frameworks(MOFs)[Fe(dpo){Ag(CN)_(2)}_(2)]·3DMF(1)and[Fe(dpo){Ag(CN)_(2)}_(2)]·0.5MeCN·2DEF(2),which exhibit vip dependent four-step SCO behaviors with the sequences of LS→~LS_(2/3)HS_(1/3)→LS_(1/2)HS_(1/2)→~LS_(3/10)HS_(7/10)→HS and LS→~LS_(2/3)HS_(1/3)→LS_(1/2)HS_(1/2)→~LS_(1/4)HS_(3/4)→HS,respectively.Therefore,the incorporation of hydrogen-donating/hydrogen-accepting groups into the Hofmann-type MOFs may effectively explore the multi-step SCO materials by tuning hydrogen-bonding interactions.
文摘A two-dimensional cyanide-bridged Cu(Ⅱ)-Pt(Ⅱ) bimetallic complex has been synthesized by solution diffusion method using [Pt (CN)4]2- and [Cu (L)]2+ (L =3,10-diethanol-1,3,5,8,10,12-hexaazacyclotetradecane) as building blocks. Unexpectedly, the obtained complex Cu(DMF)2[Pt(CN)4] (1) is an analogue of the well-known Hofmann -type clathrate without macrocyclic ligand. Single-crystal X-ray diffraction reveals that 1 crystallizes in monoclinic, space group C2/m, a=1.624 8(6) nm, b=0.739 3(3) nm, c=0.695 5(3) nm, β=108.969(4)°. The crystal structure of 1 consists of two-dimensional corrugated metal cyanide sheets without interpenetration stacking along the a axis in an ABAB packing mode.
基金supported by the National Key Research and Development Program of China(2018YFA0306001)the Nas tional Natural Sciences Foundation of China(21773316,21801258,21821003)the Pearl River Talent Plan of Guangdong(2017BT01C161)。
文摘Herein,we report the first example showing the reversible on-off switching of spin-crossover(SCO)property by solid state photochemical[2+2]reaction.The ultraviolet(UV)light-induced[2+2]cycloaddition reaction of 3-spy ligands in a twodimensional(2D)Hofmann-type framework[Fe(3-spy)_(2){Pd(CN)_(4)}](1,3-spy=3-styrylpyridine),which shows a hysteretic twostep SCO behavior,gives a 3D Hofmann-type framework[Fe(rctt-3-ppcb){Pd(CN)_(4)}](2,rctt-3-ppcb=rctt-1,3-bis(3-pyridyl)-2,4-bis(phenyl)cyclobutane,r=reference group,c=cis and t=trans)accompanied with the disappearing of SCO properties.Moreover,upon heating at 250℃ for 12 h,the rctt-3-ppcb ligand in 2 could be partially dedimerized to 3-spy with 68%completion through single-crystal-to-single-crystal(SCSC)transformation,giving the annealing complexes[Fe(3-spy)1.36(rctt-3-ppcb)0.32{Pd(CN)_(4)}](3)which display an incomplete SCO behavior.The 2■3 interconversion is successfully achieved via continuous UV irradiation and thermal annealing,demonstrating the effectiveness of photochemical[2+2]reaction on switching on-off SCO properties.
