The emergence of molecular spintronics offers a unique chance for the design of molecular devices with different spin-states,and the control of spin-state becomes essential for molecular spin switches.However,the intr...The emergence of molecular spintronics offers a unique chance for the design of molecular devices with different spin-states,and the control of spin-state becomes essential for molecular spin switches.However,the intrinsic spin switching from low-to high-spin state is a temperature-dependent process with a small energy barrier where low temperature is required to maintain the low-spin state.Thus,the room-temperature operation of single-molecule devices has not yet been achieved.Herein,we present a reversible single-molecule conductance switch by manipulating the spin states of the molecule at room temperature using the scanning tunneling microscope break-junction(STM-BJ)technique.The manipulation of the spin states between S=0 and S=1 is achieved by complexing or decomplexing the pyridine derivative molecule with a square planar nickel(Ⅱ)porphyrin.The bias-dependent conductance evolution proves that the strong electric field between the nanoelectrodes plays a crucial role in the coordination reaction.The density functional theory(DFT)calculations further reveal that the conductance changes come from the geometric changes of the porphyrin ring and spin-state switching of the Ni(Ⅱ)ion.Our work provides a new avenue to investigate room-temperature spin-related sensors and molecular spintronics.展开更多
2024年6月10日,《自然·通讯》(Nature Communications)在线发表了重庆大学光电工程学院臧志刚教授团队题为“Silver Coordination-Induced n-Doping of PCBM Enables Highly Efficient and Stable Inverted Perovskite Solar Cell...2024年6月10日,《自然·通讯》(Nature Communications)在线发表了重庆大学光电工程学院臧志刚教授团队题为“Silver Coordination-Induced n-Doping of PCBM Enables Highly Efficient and Stable Inverted Perovskite Solar Cells”的研究成果。该团队提出了一种银配位诱导的n型掺杂策略,成功解决了钙钛矿太阳能电池中卤化物与银电极的双向迁移问题,为提升器件长期稳定性提供了创新性解决方案。钙钛矿太阳能电池因其高效率和低成本成为光伏领域的研究热点,但卤化物离子(如碘)与银电极的不可逆化学腐蚀严重制约其实际应用。展开更多
Mercury is one of the major toxic pollutants and has many adverse effects on human health. The main mercury species in the environment or in living organisms are inorganic mercuric ion （Hg2＋） and organic methylmerc...Mercury is one of the major toxic pollutants and has many adverse effects on human health. The main mercury species in the environment or in living organisms are inorganic mercuric ion （Hg2＋） and organic methylmercury （CH3Hg＋）. Detection of the two mercury ions is a particularly active topic in the molecular sensing field during the past decade. However, efficient sensors that can sensitively detect and discriminate the two species are rare. In this work, we adopt the concept of restriction of intramolecular rotations which is the basis of aggregation induced emission, and design a molecular probe with pyridyl group as the chelating unit and 1,8-naphthalimide as the fluorescent unit for the detection of both Hg2＋ and CH3Hg＋. When the probe is free in solution, it exhibits weak fluorescence because free intramolecular rotations of the 1,8-naphthalimide moieties non-radiatively annihilate its excited state. However, upon coordination with Hg2＋ or CH3Hg＋, the rotation of 1,8-naphthalimide moieties would be restricted due to the chelation between 1,8-naphthalimide and Hg2＋ or CH3Hg＋, leading to significantly enhanced fluorescent emission. The response induced by Hg2＋ is much stronger than CH3Hg＋; but for specific detection of CH3Hg＋, we introduced a T-rich DNA fragment which could completely mask Hg2＋ in solution. Furthermore, we have employed the sensor for confocal imaging of rig2＋ and CH3Hg＋in immobilized cells. We expect the probe design tactics can be generally useful for sensing many other analytes.展开更多
基金supported by the National Natural Science Foundation of China(nos.21673195,21722305,21703188,21973079,and 21933012)the National Key R&D Program of China(no.2017YFA0204902)+2 种基金supported by the FET Open project 767187-QuIETthe EU project BAC-TO-FUELthe UK EPSRC grants EP/N017188/1 and EP/M014452/1 in Lancaster.
文摘The emergence of molecular spintronics offers a unique chance for the design of molecular devices with different spin-states,and the control of spin-state becomes essential for molecular spin switches.However,the intrinsic spin switching from low-to high-spin state is a temperature-dependent process with a small energy barrier where low temperature is required to maintain the low-spin state.Thus,the room-temperature operation of single-molecule devices has not yet been achieved.Herein,we present a reversible single-molecule conductance switch by manipulating the spin states of the molecule at room temperature using the scanning tunneling microscope break-junction(STM-BJ)technique.The manipulation of the spin states between S=0 and S=1 is achieved by complexing or decomplexing the pyridine derivative molecule with a square planar nickel(Ⅱ)porphyrin.The bias-dependent conductance evolution proves that the strong electric field between the nanoelectrodes plays a crucial role in the coordination reaction.The density functional theory(DFT)calculations further reveal that the conductance changes come from the geometric changes of the porphyrin ring and spin-state switching of the Ni(Ⅱ)ion.Our work provides a new avenue to investigate room-temperature spin-related sensors and molecular spintronics.
文摘2024年6月10日,《自然·通讯》(Nature Communications)在线发表了重庆大学光电工程学院臧志刚教授团队题为“Silver Coordination-Induced n-Doping of PCBM Enables Highly Efficient and Stable Inverted Perovskite Solar Cells”的研究成果。该团队提出了一种银配位诱导的n型掺杂策略,成功解决了钙钛矿太阳能电池中卤化物与银电极的双向迁移问题,为提升器件长期稳定性提供了创新性解决方案。钙钛矿太阳能电池因其高效率和低成本成为光伏领域的研究热点,但卤化物离子(如碘)与银电极的不可逆化学腐蚀严重制约其实际应用。
基金funded by the National Basic Research Program of China(2013CB932800)the National Natural Science Foundation of China(21375130,31571010,21204089 and 21475132)
文摘Mercury is one of the major toxic pollutants and has many adverse effects on human health. The main mercury species in the environment or in living organisms are inorganic mercuric ion （Hg2＋） and organic methylmercury （CH3Hg＋）. Detection of the two mercury ions is a particularly active topic in the molecular sensing field during the past decade. However, efficient sensors that can sensitively detect and discriminate the two species are rare. In this work, we adopt the concept of restriction of intramolecular rotations which is the basis of aggregation induced emission, and design a molecular probe with pyridyl group as the chelating unit and 1,8-naphthalimide as the fluorescent unit for the detection of both Hg2＋ and CH3Hg＋. When the probe is free in solution, it exhibits weak fluorescence because free intramolecular rotations of the 1,8-naphthalimide moieties non-radiatively annihilate its excited state. However, upon coordination with Hg2＋ or CH3Hg＋, the rotation of 1,8-naphthalimide moieties would be restricted due to the chelation between 1,8-naphthalimide and Hg2＋ or CH3Hg＋, leading to significantly enhanced fluorescent emission. The response induced by Hg2＋ is much stronger than CH3Hg＋; but for specific detection of CH3Hg＋, we introduced a T-rich DNA fragment which could completely mask Hg2＋ in solution. Furthermore, we have employed the sensor for confocal imaging of rig2＋ and CH3Hg＋in immobilized cells. We expect the probe design tactics can be generally useful for sensing many other analytes.
