Long-Range Ferromagnetic Exchange Interactions Mediated by Mn-CeIV-Mn Superexchange Involving Empty 4f Orbitals

De novo synthesis of hybrid d-f block metal complex salts for electronic charge transport applications

The advent of d-d type complex salts for designing smart functional materials with versatile utility inspired us to develop a novel type of M(II)-Ce(IV) complex salts [M(II) = Cu and Zn ions]. In this study, we present for the first time a holistic approach to design and prepare metal complex salts of the novel hybrid d-f block type, [Cu(bpy)₂]₂[Ce(NO₃)₆]₂ (1), [Cu(phen)₂(NO₃)]₂[Ce(NO₃)₆](HNO₃) (2), [Zn(bpy)₂(NO₃)][ClO₄] (3), and [Zn(phen)₂(NO₃)]₂ [Ce(NO₃)₆] (4); [bpy = 2,2'-bipyridine; phen = 1,10-phenanthroline]. The intrinsic structural and morphological properties of the compounds have been revealed by employing a suite of analytical and spectroscopic methods. X-ray structural analysis reveals that the copper(II) centres in the cationic complex units of 1 and 2 adopt a highly distorted tetrahedral and a rare bicapped square pyramidal coordination geometry, respectively. The zinc(II) ions in both 3 and 4 adopt the rare bicapped square pyramidal geometry while the cerium(IV) ions in 1, 2 and 4 exist in a dodecahedral geometry. Investigation of supramolecular interactions reveals that intermolecular O⋯H and O⋯π short contacts bind the complex units in 1, while predominant π⋯π interactions, along with O⋯H and O⋯π short contacts, produce the binding force among the complex units in 2. We further employed the complex salts (1-4) to construct Schottky devices to reveal the role of these new complex salts in the charge-transport phenomenon. The carrier mobilities (μ) for salts 1-4 were determined to be 1.76 × 10^-6, 9.02 × 10^-6, 1.86 × 10^-8, and 4.31 × 10^-8 m² V^-1 s^-1, with respective transit times (τ) of 439, 85, 4.17 × 10³, and 1.79 × 10³ ns, which suggest that complex salt 2 is the best candidate with the highest transport properties among all the complex salts. A crystal engineering perspective sheds light on the charge-transport properties of the complex salts, emphasizing the attribution of the best performance of 2 to its predominant π⋯π interactions. The synthesis of this new type of complex salts, their physicochemical properties and their charge-transport applications envisage great promise for the development of novel crystalline materials with smart functionalities.

Structures and magnetic properties of two heterometallic Cu(ii)–Cd(ii) polymers exhibiting antiferromagnetic ordering

Two heterometallic Cu(ii)–Cd(ii) polymers (1 and 2) with a 2D layer or 1D chain structure were obtained and their magneto-structural correlations were discussed, and 1 displayed antiferromagnetic ordering at lower temperature.

Dynamic Metal Exchange between a Metalloid Silver Cluster and Silver(I) Thiolate

Although a homometallic (isotopic metal) exchange reaction has been reported, the in-depth understanding of the interaction between a metalloid cluster and the homometal (representing the same metal element as the metalloid cluster) thiolate is quite limited, especially at the atomic level. Herein, based on Ag₄₄(SR)₃₀ (where SR represents 4-mercaptobenzoic acid), we report a facile approach for investigating the metalloid cluster-homometal thiolate interaction at the atomic level, i.e., isotopic exchange in the Ag metalloid cluster. Since such a reaction takes no account of the enthalpy change-related heterometal (representing a different metal element) exchange, the intrinsic metalloid cluster-homometal thiolate interaction can be thoroughly investigated. Through analyzing the ESI-MS (electrospray ionization mass spectrometry) and MS/MS (mass/mass spectrometry) results of the reversible conversion between ¹⁰⁷Ag₄₄(SR)₃₀ and ¹⁰⁹Ag₄₄(SR)₃₀, we observed that all Ag atoms are exchangeable in the Ag₄₄(SR)₃₀ template. In addition, through analyzing the ESI-MS results of the interconversion between ¹⁰⁷Ag₂₉(BDT)₁₂(TPP)₄ and ¹⁰⁹Ag₂₉(BDT)₁₂(TPP)₄, we demonstrated that the metal exchange in the Ag₂₉(BDT)₁₂(TPP)₄ metalloid cluster should be a shell → kernel metal transfer process. Our results provide new insights into the metalloid cluster reactivity in the homometal thiolate environment, which will guide the future preparation of metalloid clusters with customized structures and properties.