By using a carbazole derived triangular carboxylic ligand,a Zn(II)based metal–organic framework(MOF)revealing a high porosity framework structure and carbazole based intense blue-light emission is obtained.The struct...By using a carbazole derived triangular carboxylic ligand,a Zn(II)based metal–organic framework(MOF)revealing a high porosity framework structure and carbazole based intense blue-light emission is obtained.The structural and photophysical characteristics of the MOF make it an ideal energy transfer platform for the accommodation and sensitization of red and green fluorescent dyes for the tuning of white light emission.By simultaneously introducing red and green fluorescent dyes into the host MOF framework and carefully controlling their contents,a high performance white-light-emitting luminophore was obtained.The luminophor reveals Commission International de l’Eclairage(CIE)coordinates of(0.32,0.31),a correlated colour temperature(CCT)of 6186 K,a colour-rendering index(CRI)of 91,and a high quantum yield of up to 39.4%,which could be a candidate for application in white-light-emitting diodes(WLEDs).展开更多
Under solvothermal conditions,five chiral 3d–4f wheel-like heterometallic hexanuclear clusters with the Schiff base ligand[H_(2) L=N,N’-bis(3-methoxysalicylidene)-1,3-diaminopropane]were synthesized by the in situ l...Under solvothermal conditions,five chiral 3d–4f wheel-like heterometallic hexanuclear clusters with the Schiff base ligand[H_(2) L=N,N’-bis(3-methoxysalicylidene)-1,3-diaminopropane]were synthesized by the in situ ligand reaction of the 1,3-bis(2-pyridyl)-1,3-propanedione and generated the pyridine-2-carboxylate(PyCO_(2)^(−))that acted as a bridging ligand;a peroxide anion formed by the spontaneous reduction of dioxygen plays a key role in the assembly of these complexes.The five isomeric 3d–4f heterometallic complexes,with molecular formula[M_(3)Ln_(3)(O_(2))L_(3)(PyCO_(2))_(3)](OH)_(2)(ClO4)_(2)·8H_(2) O(M=Zn,Cu;Ln=Dy,Tb,Gd)represent the first anion-orientated chiral heterometallic cluster complexes composed of achiral components.Except for complex 1,we randomly measured the crystal structure of one of the two chiral enantiomers of complexes 2–5.Magnetic measurements show that the Zn_(3)Gd_(3) complex exhibits a moderate magnetocaloric effect.The Cu_(3)Tb_(3) complex is a single-molecule magnet(SMM)with an energy barrier(Ueff/k)value of 31.7(0.3)K under zero dc field,which is a larger value for Cu–Tb SMMs;the other three compounds Zn_(3)Dy_(3),Zn_(3)Tb_(3),and Cu_(3)Dy_(3) exhibit field-induced magnetic relaxation.The Ueff/k value of Zn_(3)Dy_(3)[>100 K,H_(dc)=1000 Oe]is obviously larger than those of equilateral triangular Dy_(3) complexes(≤62 K).展开更多
基金supported by the NSFC(21531005,91622111,21673120,and 21601028)the MOE Innovation Team of China(IRT_17R57)the Natural Science Fund of Tianjin,China(16JCZDJC36900).
文摘By using a carbazole derived triangular carboxylic ligand,a Zn(II)based metal–organic framework(MOF)revealing a high porosity framework structure and carbazole based intense blue-light emission is obtained.The structural and photophysical characteristics of the MOF make it an ideal energy transfer platform for the accommodation and sensitization of red and green fluorescent dyes for the tuning of white light emission.By simultaneously introducing red and green fluorescent dyes into the host MOF framework and carefully controlling their contents,a high performance white-light-emitting luminophore was obtained.The luminophor reveals Commission International de l’Eclairage(CIE)coordinates of(0.32,0.31),a correlated colour temperature(CCT)of 6186 K,a colour-rendering index(CRI)of 91,and a high quantum yield of up to 39.4%,which could be a candidate for application in white-light-emitting diodes(WLEDs).
基金support from the National Natural Science Foundation of China(21471154 and 91022014)the Strategic Priority Research Program of the Chinese Academy of Sciences(XDB12010103).
文摘Under solvothermal conditions,five chiral 3d–4f wheel-like heterometallic hexanuclear clusters with the Schiff base ligand[H_(2) L=N,N’-bis(3-methoxysalicylidene)-1,3-diaminopropane]were synthesized by the in situ ligand reaction of the 1,3-bis(2-pyridyl)-1,3-propanedione and generated the pyridine-2-carboxylate(PyCO_(2)^(−))that acted as a bridging ligand;a peroxide anion formed by the spontaneous reduction of dioxygen plays a key role in the assembly of these complexes.The five isomeric 3d–4f heterometallic complexes,with molecular formula[M_(3)Ln_(3)(O_(2))L_(3)(PyCO_(2))_(3)](OH)_(2)(ClO4)_(2)·8H_(2) O(M=Zn,Cu;Ln=Dy,Tb,Gd)represent the first anion-orientated chiral heterometallic cluster complexes composed of achiral components.Except for complex 1,we randomly measured the crystal structure of one of the two chiral enantiomers of complexes 2–5.Magnetic measurements show that the Zn_(3)Gd_(3) complex exhibits a moderate magnetocaloric effect.The Cu_(3)Tb_(3) complex is a single-molecule magnet(SMM)with an energy barrier(Ueff/k)value of 31.7(0.3)K under zero dc field,which is a larger value for Cu–Tb SMMs;the other three compounds Zn_(3)Dy_(3),Zn_(3)Tb_(3),and Cu_(3)Dy_(3) exhibit field-induced magnetic relaxation.The Ueff/k value of Zn_(3)Dy_(3)[>100 K,H_(dc)=1000 Oe]is obviously larger than those of equilateral triangular Dy_(3) complexes(≤62 K).
