Supramolecular non-covalent interactions,which drive the molecular packing of crystalline functional molecular materials,can be employed as effective tools for mediating magnetic exchange interactions.Specifically,dir...Supramolecular non-covalent interactions,which drive the molecular packing of crystalline functional molecular materials,can be employed as effective tools for mediating magnetic exchange interactions.Specifically,directional hydrogen-and halogen-bonds andπ-πinteractions can be used to design materials in which their magnetic exchange pathways and strength can increasingly be predicted.Specific examples are presented herein and discussed with the aim of gaining deeper insight into the structure-property relationships that provide a powerful tool to afford new materials with unprecedented physical properties.展开更多
Here we report on one-dimensional nano objects of formula[Yb(hfac)_(3)(M-or P-Ant-C8)]_(n) where the Ant-C8 moiety refers to enantiopure M-and P-twistacenes decorated at positions 2,6 with 4-pyridyl-ethynyl units and ...Here we report on one-dimensional nano objects of formula[Yb(hfac)_(3)(M-or P-Ant-C8)]_(n) where the Ant-C8 moiety refers to enantiopure M-and P-twistacenes decorated at positions 2,6 with 4-pyridyl-ethynyl units and helically locked into an end-to-end twist by an octyl tether.The crystal structure analysis reveals intertwined 1D nano-chains featuring two crystallographically independent Yb(III)ions.Under applied magnetic fields these systems show slow relaxation of the magnetization.The optical properties show the expected contributions of the ^(2)F_(7/2)←^(2)F_(5/2) electronic transition of the Yb(III)ions split by the crystal field.Magnetic field and temperature dependent Magneto-Chiral Dichroism(MChD)studies reveal contributions of opposite sign and similar intensity for the two crystallographically independent ions that cancel out for the 0-0′and 0-2′absorptions but not for the 0-1′.These findings,supported by ab intio theoretical calculations,demonstrate the important role of the structural arrangement of MChD-active ions when designing chiral magneto-optical materials responsive to light and magnetic fields.展开更多
Magneto-Chiral Dichroism(MChD)is an enantioselective and polarization independent light-matter interaction shown by magnetized chiral molecules and materials.This phenomenon,predicted in 1984 and experimentally demons...Magneto-Chiral Dichroism(MChD)is an enantioselective and polarization independent light-matter interaction shown by magnetized chiral molecules and materials.This phenomenon,predicted in 1984 and experimentally demonstrated in 1997 by studying the differential visible light emission of a chiral Eu^(Ⅲ) complex,is now attracting the interest of the chemical community working with transition metal and lanthanide-based chiral complexes.This is motivated by both the information on the magnetic,electronic and chiroptical properties that can be retrieved using this unconventional spectroscopic technique and the potential technological applications that can be foreseen,such as the optical readout of magnetic data without the need for polarization-based readout devices.In particular,chiral lanthanide complexes,which intrinsically have high spin-orbit coupling(a key factor to observe MChD),a variety of electronic configurations,a multitude of electronic transitions of different characteristics,variable coordination geometries and different degrees of magnetic anisotropy,represent ideal molecules to investigate MChD in both light absorption and emission in a wide spectral range.This perspective summarizes the studies reported so far in the literature on the MChD of chiral lanthanide complexes and provides some general conclusions that will help the chemical community in designing lanthanide-based systems highly responsive to MChD.Finally,we suggest prospective experiments and studies that are needed to push forward the understanding and the use of this fascinating phenomenon.展开更多
文摘Supramolecular non-covalent interactions,which drive the molecular packing of crystalline functional molecular materials,can be employed as effective tools for mediating magnetic exchange interactions.Specifically,directional hydrogen-and halogen-bonds andπ-πinteractions can be used to design materials in which their magnetic exchange pathways and strength can increasingly be predicted.Specific examples are presented herein and discussed with the aim of gaining deeper insight into the structure-property relationships that provide a powerful tool to afford new materials with unprecedented physical properties.
基金The French National Research Agency(ANR)is acknowledged for financial support through the SWITCH-MChD(ANR-23-CE07-0003)PRINCIPE(ANR-23-CE07-0015)projects+2 种基金This project has received financial support from the CNRS through the MITI interdisciplinary programs through its exploratory research programThe French GENCI/IDRIS-CINES centers for high-performance computing resources are also acknowledged.O.G.acknowledges European Union's Horizon 2020 research and innovation program(grant agreement no.850836,ERC Starting Grant“PolyHelix”)the Israel Science Foundation(grant no.3085/21).
文摘Here we report on one-dimensional nano objects of formula[Yb(hfac)_(3)(M-or P-Ant-C8)]_(n) where the Ant-C8 moiety refers to enantiopure M-and P-twistacenes decorated at positions 2,6 with 4-pyridyl-ethynyl units and helically locked into an end-to-end twist by an octyl tether.The crystal structure analysis reveals intertwined 1D nano-chains featuring two crystallographically independent Yb(III)ions.Under applied magnetic fields these systems show slow relaxation of the magnetization.The optical properties show the expected contributions of the ^(2)F_(7/2)←^(2)F_(5/2) electronic transition of the Yb(III)ions split by the crystal field.Magnetic field and temperature dependent Magneto-Chiral Dichroism(MChD)studies reveal contributions of opposite sign and similar intensity for the two crystallographically independent ions that cancel out for the 0-0′and 0-2′absorptions but not for the 0-1′.These findings,supported by ab intio theoretical calculations,demonstrate the important role of the structural arrangement of MChD-active ions when designing chiral magneto-optical materials responsive to light and magnetic fields.
基金the financial support through the SWITCH-MChD(ANR-23-CE07-0003)MaChiNaCo(ANR-19-CE09-0018)projects.
文摘Magneto-Chiral Dichroism(MChD)is an enantioselective and polarization independent light-matter interaction shown by magnetized chiral molecules and materials.This phenomenon,predicted in 1984 and experimentally demonstrated in 1997 by studying the differential visible light emission of a chiral Eu^(Ⅲ) complex,is now attracting the interest of the chemical community working with transition metal and lanthanide-based chiral complexes.This is motivated by both the information on the magnetic,electronic and chiroptical properties that can be retrieved using this unconventional spectroscopic technique and the potential technological applications that can be foreseen,such as the optical readout of magnetic data without the need for polarization-based readout devices.In particular,chiral lanthanide complexes,which intrinsically have high spin-orbit coupling(a key factor to observe MChD),a variety of electronic configurations,a multitude of electronic transitions of different characteristics,variable coordination geometries and different degrees of magnetic anisotropy,represent ideal molecules to investigate MChD in both light absorption and emission in a wide spectral range.This perspective summarizes the studies reported so far in the literature on the MChD of chiral lanthanide complexes and provides some general conclusions that will help the chemical community in designing lanthanide-based systems highly responsive to MChD.Finally,we suggest prospective experiments and studies that are needed to push forward the understanding and the use of this fascinating phenomenon.
