More Like this

1. Magnetic properties of two Gd III Fe III 4 metallacrowns and strategies for optimizing the magnetocaloric effect of this topology

   https://doi.org/10.1039/D1QI00207D  

   Salerno, Elvin V. ; Kampf, Jeff W. ; Pecoraro, Vincent L. ; Mallah, Talal ( May 2021 , Inorganic Chemistry Frontiers)

   Two Gd III Fe III 4 metallacrown complexes are presented and analyzed for their magnetic properties. One of these species is newly identified and exhibits a bent ring geometry as opposed to the more conventional flatter conformation of the other. Both complexes are quite similar magnetically, exhibiting antiferromagnetic exchange coupling values ca . J (Fe III –N–O–Fe III ) = −7 cm −1 and J (Gd III –O–Fe III ) = −0.7 cm −1 . When analyzed for the molecular magnetocaloric effect, maximum −Δ S m values of 7.3 J K −1 kg −1 at 3 K and at 6.1 J K −1 kg −1 at 4 K were exhibited. A detailed structural-magnetic correlation is established and an assessment of several similar magnetic metallacrowns with diverse metal combinations is given with regards to their potential magnetocaloric properties. Strategies for improving the magnetocaloric properties within the Metaln + FeIII4 family of metallacrowns are proposed regarding the ratio between coupling parameters J (Fe III –N–O–Fe III )/ J (Metal n+ –O–Fe III ). 

   more » « less
2. Two-photon pathway to ultracold ground state molecules of 23 Na 40 K

   https://doi.org/10.1088/1367-2630/17/7/075016  

   Park, Jee Woo ; Will, Sebastian A. ; Zwierlein, Martin W. ( July 2015 , New Journal of Physics)
3. A Contiguous Tricyclic [P 6 ] 2– Framework Spanning Across Two Vanadium(III) Centers

   https://doi.org/10.1021/acs.organomet.2c00638  

   Senthil, Shuruthi ; Gau, Michael R. ; Mindiola, Daniel J. ( February 2023 , Organometallics)

   Paul Chirik (Ed.)

   The complex [(BDI)VCl(N{SiMe3}2)] (1) (BDI– = [ArNC(CH3)]2CH, Ar = 2,6-iPr2C6H3), a precursor readily prepared from metathesis of [(BDI)VCl2] and Na[N{SiMe3}2], can be reduced with Na/NaCl in the presence of white P4 to form a dinuclear species containing two VIII centers bridged by a tricyclic [P6]2– scaffold, namely, [(BDI)V(N{SiMe3}2)]2(μ-η1:η1-P6) (2). Coordination of [P6]2– involves a unique chairlike μ-η1:η1 binding mode with a contiguous tricyclic hexaphosphorus unit bridging across the two V centers. Complexes 1 and 2 have been structurally characterized, and a pathway toward the formation of the chairlike tricyclic [P6]2– scaffold in 2 is proposed. 

   more » « less
4. Thermal and Magnetic Field Switching in a Two‐Step Hysteretic Mn III Spin Crossover Compound Coupled to Symmetry Breakings

   https://doi.org/10.1002/anie.202114021  

   Dobbelaar, Emiel ; Jakobsen, Vibe B. ; Trzop, Elzbieta ; Lee, Minseong ; Chikara, Shalinee ; Ding, Xiaxin ; Müller‐Bunz, Helge ; Esien, Kane ; Felton, Solveig ; Carpenter, Michael A. ; et al ( December 2021 , Angewandte Chemie International Edition)

   A Mn^IIIspin crossover complex with atypical two‐step hysteretic thermal switching at 74 K and 84 K shows rich structural–magnetic interplay and magnetic‐field‐induced spin state switching below 14 T with an onset below 5 T. The spin states, structures, and the nature of the phase transitions are elucidated via X‐ray and magnetization measurements. An unusual intermediate phase containing four individual sites, whereare in a pure low spin state, is observed. The splitting of equivalent sites in the high temperature phase into four inequivalent sites is due to a structural reorganization involving a primary and a secondary symmetry‐breaking order parameter that induces a crystal system change from orthorhombic→monoclinic and a cell doubling. Further cooling leads to a reconstructive phase transition and a monoclinic low‐temperature phase with two inequivalent low‐spin sites. The coupling between the order parameters is identified in the framework of Landau theory.

    

   more » « less
5. Thermal and Magnetic Field Switching in a Two‐Step Hysteretic Mn III Spin Crossover Compound Coupled to Symmetry Breakings

   https://doi.org/10.1002/ange.202114021  

   Dobbelaar, Emiel ; Jakobsen, Vibe B. ; Trzop, Elzbieta ; Lee, Minseong ; Chikara, Shalinee ; Ding, Xiaxin ; Müller‐Bunz, Helge ; Esien, Kane ; Felton, Solveig ; Carpenter, Michael A. ; et al ( December 2021 , Angewandte Chemie)

   A Mn^IIIspin crossover complex with atypical two‐step hysteretic thermal switching at 74 K and 84 K shows rich structural–magnetic interplay and magnetic‐field‐induced spin state switching below 14 T with an onset below 5 T. The spin states, structures, and the nature of the phase transitions are elucidated via X‐ray and magnetization measurements. An unusual intermediate phase containing four individual sites, whereare in a pure low spin state, is observed. The splitting of equivalent sites in the high temperature phase into four inequivalent sites is due to a structural reorganization involving a primary and a secondary symmetry‐breaking order parameter that induces a crystal system change from orthorhombic→monoclinic and a cell doubling. Further cooling leads to a reconstructive phase transition and a monoclinic low‐temperature phase with two inequivalent low‐spin sites. The coupling between the order parameters is identified in the framework of Landau theory.

    

   more » « less