This study presents the synthesis of three dinuclear cobalt complexes based on three imine derivatives:bis-[4-(2-pyridylmethyleneamino)-phenyl]thioether(L1),bis-[4-(2-pyridylmethyleneamino)-phenyl]ether(L2),and bis-[4...This study presents the synthesis of three dinuclear cobalt complexes based on three imine derivatives:bis-[4-(2-pyridylmethyleneamino)-phenyl]thioether(L1),bis-[4-(2-pyridylmethyleneamino)-phenyl]ether(L2),and bis-[4-(2-pyridylmethyleneamino)-phenyl]methane(L3).Single-crystal X-ray diffraction analysis reveals that the complexes[Co_(2)(L1)3](ClO_(4))4·2CH_(3)CN(1),[Co_(2)(L2)3](ClO_(4))4·2CH_(3)OH(2),and[Co_(2)(L3)3](ClO_(4))4·2CH_(3)OH(3)all exhibit a dinuclear structure.Magnetic test results show that complex 3 exhibited irreversible SCO behavior induced by loss of solvent at 300 K,with the average Co-N bond length increasing from 0.2139(3)to 0.2153(3)nm.Meanwhile,the desolvated complex 3 exhibited paramagnetic behavior similar to that of complexes 1 and 2.Variable-temperature UV-Vis spectroscopic studies also indicate that complex 3 undergoes a solvent-loss-induced spin-state transition.CCDC:2347354,1(120 K);2347355,2(120 K);2347356,3(120 K);2347357,3(400 K).展开更多
The utilization of spin crossover(SCO)to modulate the luminescence properties in smart multifunctional materials and multichannel sensors is promising.However,it is challenging to build a strong coupling between SCO a...The utilization of spin crossover(SCO)to modulate the luminescence properties in smart multifunctional materials and multichannel sensors is promising.However,it is challenging to build a strong coupling between SCO and luminescence in one system.Herein,we present a mononuclear compound[Fe(tpe-abpt)_(2)(SeCN)_(2)]·4DMF(1·4DMF,tpe-abpt:(4-(1,1,2,2-tetraphenylethene))-N-(3,5-bis(pyridin-2-yl)-4H-1,2,4-triazol-4yl)methanimine)showing aggregation-induced emission(AIE)and thermally induced SCO properties.Variable-temperature single-crystal structural analysis reveals that SCO changes the number of pathways and strength of intermolecular interactions,resulting in deactivation of nonradiative decay and significant enhancement of luminescence.The photoluminescence(PL)intensity of 1·4DMF exhibited a fivefold increase upon the spin transition from the low-spin to the high-spin states.In contrast with the current strategy of controlling the Förster resonance energy transfer(FRET)process by utilizing SCO to tune the overlap degree between the emission band of the luminophore and UV–vis absorption band of high-spin and low-spin states,we developed a new approach to tune the intermolecular interactions between AIE luminogens(AIEgens)by utilizing a subtle SCO-induced structural transformation,therefore leading to effective coupling between SCO and luminescence and a significant change in luminescence upon SCO.Our results provide a rational strategy to build smartmultifunctionalizedmaterials with remarkably synergetic SCO and luminescence.展开更多
文摘This study presents the synthesis of three dinuclear cobalt complexes based on three imine derivatives:bis-[4-(2-pyridylmethyleneamino)-phenyl]thioether(L1),bis-[4-(2-pyridylmethyleneamino)-phenyl]ether(L2),and bis-[4-(2-pyridylmethyleneamino)-phenyl]methane(L3).Single-crystal X-ray diffraction analysis reveals that the complexes[Co_(2)(L1)3](ClO_(4))4·2CH_(3)CN(1),[Co_(2)(L2)3](ClO_(4))4·2CH_(3)OH(2),and[Co_(2)(L3)3](ClO_(4))4·2CH_(3)OH(3)all exhibit a dinuclear structure.Magnetic test results show that complex 3 exhibited irreversible SCO behavior induced by loss of solvent at 300 K,with the average Co-N bond length increasing from 0.2139(3)to 0.2153(3)nm.Meanwhile,the desolvated complex 3 exhibited paramagnetic behavior similar to that of complexes 1 and 2.Variable-temperature UV-Vis spectroscopic studies also indicate that complex 3 undergoes a solvent-loss-induced spin-state transition.CCDC:2347354,1(120 K);2347355,2(120 K);2347356,3(120 K);2347357,3(400 K).
基金supported by the National Natural Science Foundation of China(grant nos.22025101,91961114,21871039,22173015,22071017,and 21771049)the Fundamental Research Funds for the Central Universities,China.
文摘The utilization of spin crossover(SCO)to modulate the luminescence properties in smart multifunctional materials and multichannel sensors is promising.However,it is challenging to build a strong coupling between SCO and luminescence in one system.Herein,we present a mononuclear compound[Fe(tpe-abpt)_(2)(SeCN)_(2)]·4DMF(1·4DMF,tpe-abpt:(4-(1,1,2,2-tetraphenylethene))-N-(3,5-bis(pyridin-2-yl)-4H-1,2,4-triazol-4yl)methanimine)showing aggregation-induced emission(AIE)and thermally induced SCO properties.Variable-temperature single-crystal structural analysis reveals that SCO changes the number of pathways and strength of intermolecular interactions,resulting in deactivation of nonradiative decay and significant enhancement of luminescence.The photoluminescence(PL)intensity of 1·4DMF exhibited a fivefold increase upon the spin transition from the low-spin to the high-spin states.In contrast with the current strategy of controlling the Förster resonance energy transfer(FRET)process by utilizing SCO to tune the overlap degree between the emission band of the luminophore and UV–vis absorption band of high-spin and low-spin states,we developed a new approach to tune the intermolecular interactions between AIE luminogens(AIEgens)by utilizing a subtle SCO-induced structural transformation,therefore leading to effective coupling between SCO and luminescence and a significant change in luminescence upon SCO.Our results provide a rational strategy to build smartmultifunctionalizedmaterials with remarkably synergetic SCO and luminescence.
