More Like this

1. From spin-crossover to single molecule magnetism: tuning magnetic properties of Co( ii ) bis-ferrocenylterpy cations via supramolecular interactions with organocyanide radical anions

   https://doi.org/10.1039/d0tc00830c  

   Xie, Haomiao ; Vignesh, Kuduva R. ; Zhang, Xuan ; Dunbar, Kim R. ( June 2020 , Journal of Materials Chemistry C)

   TCNQ (7,7,8,8-tetracyanoquinodimethane) anion-radical derivatives were used to fine tune the magnetic properties of the [Co II (Fctp) 2 ] 2+ (Fctp = 4′-(2-ferrocenyl)-2,2′:6′2′′-terpyridine) cation in the solid state. The cocrystallization of [Co II (Fctp) 2 ] 2+ with TCNQ˙ − yielded the two pseudo-polymorphic products [Co II (Fctp) 2 ] (TCNQ) 2 ( 1 ) and [Co II (Fctp) 2 ] (TCNQ) 2 ·MeCN ( 2 ) whereas the analogous reaction with TCNQF˙ − (TCNQF = 2-fluoro-7,7,8,8-tetracyanoquinodimethane) exclusively yielded [Co II (Fctp) 2 ] (TCNQF) 2 ·MeCN ( 3 ). Compound 1 exhibits slow relaxation of magnetization under an applied DC field with U eff = 19.1 K and τ 0 = 9.8 × 10 −6 s. Compounds 2 and 3 are isostructural but exhibit different spin-crossover behavior with transition temperatures of T 1/2 = 336 K and 226 K, respectively. Investigations of the solid state structures by DFT calculations indicate that the differences in magnetic properties of the cationic moiety, [Co II (Fctp) 2 ] 2+ , are induced by supramolecular interactions between [Co II (Fctp) 2 ] 2+ and tunable TCNQ˙ − /TCNQF˙ − anion-radical derivatives. 

   more » « less
2. Insights on the Structure in Solution of Paramagnetic Ln III /Ga III 12-Metallacrown-4 Complexes Using 1D 1 H NMR and Model Structures

   https://doi.org/10.1021/acs.inorgchem.3c00983  

   Melegari, Matteo ; Marzaroli, Vittoria ; Polisicchio, Rosy ; Seletti, Davide ; Marchiò, Luciano ; Pecoraro, Vincent L. ; Tegoni, Matteo ( July 2023 , Inorganic Chemistry)
3. Unique Dimerization Topology and Countercation Binding Modes in 12‐Metallacrown‐4 Compounds

   https://doi.org/10.1002/ejic.202200439  

   Salerno, Elvin V. ; Foley, Collin M. ; Marzaroli, Vittoria ; Schneider, Bernadette L. ; Sharin, Max D. ; Kampf, Jeff W. ; Marchiò, Luciano ; Zeller, Matthias ; Guillot, Régis ; Mallah, Talal ; et al ( September 2022 , European Journal of Inorganic Chemistry)

   Seven dimeric metallacrowns (MC) based on Ln[12‐MC_M(III)N(shi)‐4], where Ln^III=Dy, Ho, Yb, or Y, M^III=Mn or Ga, and shi³⁻is salicylhydroximate, have been synthesized and characterized by single‐crystal X‐ray diffraction, and for the dysprosium‐manganese dimers, the magnetic properties have been measured. In each dimer two Ln[12‐MC_M(III)N(shi)‐4] units are linked by four bridging dicarboxylate anions (isophthalate, trimesate, dinicotinate, or 2,2′‐dithiodibenzoate). Three different countercations (sodium, gallium(III), or pyridinium) were used to maintain charge balance of the dimer. While pyridinium does not bind to the dimer, the choice of the dicarboxylate dictates where the countercations Na⁺or Ga^IIIbind. With isophthalate and trimesate, the sodium ion binds to the central MC cavity opposite of the Ln^III, and with dinicotinate the sodium or gallium(III) ions bind to the pyridyl nitrogen of the dinicotinate. All three Dy₂Mn₈dimers exhibit an out‐of‐phase magnetic susceptibility signal consistent with a shallow barrier to magnetization relaxation.

    

   more » « less
4. Multinary Tetrahedrite (Cu 12–x–y M x N y Sb 4 S 13 ) Nanoparticles: Tailoring Thermal and Optical Properties with Copper-Site Dopants

   https://doi.org/10.1021/acs.chemmater.3c03110  

   Daniel, Jacob E. ; Jesby, Christian M. ; Plass, Katherine E. ; Anderson, Mary E. ( March 2024 , Chemistry of Materials)
5. Characterization of the Ligand Field in Pseudo‐Octahedral Ni(II) Complexes of Pincer‐Type Amido Ligands: Magnetism, Redox Behavior, Electronic Absorption and High‐Frequency and ‐Field EPR Spectroscopy

   https://doi.org/10.1002/ejic.202300446  

   Ortiz, Robert J. ; Shepit, Michael ; van Lierop, Johan ; Krzystek, J. ; Telser, Joshua ; Herbert, David E. ( August 2023 , European Journal of Inorganic Chemistry)

   The description of π‐donor amido moieties as ‘weak‐field’ ligands can belie the influence of metal‐ligand covalency on the overall ligand field of coordination complexes, which can in turn influence properties including the magnetic ground state and those of their excited states. In this contribution, the ligand fields of pseudo‐octahedral Ni(II) complexes supported by diarylamido pincer‐type amido ligands – three previously reported examples supported by asymmetric (2‐R‐phenanthridin‐4‐yl)(8‐quinolinyl)amido ligands (R = Cl, CF₃,tBu;^RL¹) along with a new congener bearing a symmetricbis(8‐quinolinyl)amido ligand (BQA;L²) – were investigated in two ways. First, high‐frequency and ‐field electron paramagnetic resonance spectroscopy (HFEPR), SQUID magnetometry, and electronic absorption spectroscopy were used to determine the ligand field parameters. Second, the ability to electrochemically address ligand‐based oxidations despite metal‐centered SOMOs in the parentS=1 paramagnets was investigated, supported by time‐dependent density functional theory (TDDFT) identification of strong intervalence charge‐transfer (IVCT) transitions attributed to electronic communication between two N_amidomoieties mediated by a Ni(II) bridge. These findings are discussed in the broader context of 3d transition metal coordination complexes of weak‐field π‐donor ligands.

    

   more » « less