Reversible polymorphic structural transition of crown-like nickel nanoclusters and its effect on conductivity

Abstract

We report the reversible polymorphic phase transition of [Ni6(PET)12] (PET = phenylethanethiol) and its effect on the conductivity. This cluster's self-assembly leads to two polymorphic structures with distinct conductivity, caused...

Solvent-Mediated Separation and Reversible Transformation of 1D Supramolecular Polymorphs Built from [W10O32]4– Templated 48-Nuclei Silver(I) Cluster

“…As has already been evidenced, the structural arrangement of the 1D supramolecular chains in the crystal lattice has a significant effect on the properties; even a subtle difference can strongly influence the emission behavior. − , In order to probe the influence of noncovalent interaction on the optical properties, the temperature-dependent photoluminescence spectra of each pure supramolecular polymorph in the solid state were carried out. As shown in Figure a,b, the two polymorphs exhibit clearly different emission behaviors.…”

“…Recently, cluster-based supramolecular assemblies (one-, two-, or three-dimensional (1D, 2D, or 3D, respectively)) that use clusters as the nanobuilding block bridged by intercluster linkers (e.g., multidentate organic or inorganic ligands) manifest superior functions like better stability as well as improved optical, catalytic, or chiral properties in comparison with unassembled clusters. − Design and fabrication of these extended structures is therefore of significant importance and crucial for understanding the fundamental molecular and thermodynamic principles that dominate the assembly process. In fact, the crystal packing is not only governed by the strong coordination bond but also significantly influenced by noncovalent intermolecular interactions (e.g., hydrogen bond, van der Waals, π···π, and C–H···π interactions), leading to more than one crystalline form being crystallized. − This phenomenon is called polymorphism, which is a common phenomenon in nature and is of particular importance in the pharmaceutical industry since different polymorphs may have distinct properties like stability, solubility, and bioavailability. − Therefore, the polymorphs are considered as ideal systems to study structure–property correlations and a central preoccupation in many areas including atomically precise metal clusters. − However, the polymorphism phenomenon remains poorly understood, and the reliable protocols for having control over the crystallization process to realize the separation of different forms and selectively get one desired form remains mysterious and challengeable. − Up to now, only a few examples of cluster-based polymorphs have been reported, and no report on cluster-based supramolecular polymorphs was found. − …”

Electrocatalytic Reduction of Nitrogen to Ammonia Using Tiara‐like Phenylethanethiolated Nickel Cluster

“…This cluster was synthesized from the known procedure. [28] The synthesis of nickel-thiolate cluster involves reduction of nickel metal ion in one phase method using tetrahydrofuran (THF) as solvent and 2-phenylethanethiol as ligand (see supporting file for further details). After stirring for 7 h, the crude residue obtained by solvent evaporation was washed several times using ethanol.…”

Emergent properties in supercrystals of atomically precise nanoclusters and colloidal nanocrystals

“…three orders of magnitude conductivity increase upon a reversible structural transformation of Ni 6 (PET) 12 NCL SCs (PET = phenylethanethiol) upon heating to 130 1C. 212 While both SC types had the same monoclinic space group, their structures differed in the non-covalent ligand-ligand interactions, specifically the SÁ Á ÁS distances between neighbouring PET moieties. For the more conductive polymorph, a shorter SÁ Á ÁS distance was detected (3.78 Å vs. 4.00 Å).…”

“…For the more conductive polymorph, a shorter SÁ Á ÁS distance was detected (3.78 Å vs. 4.00 Å). 212 Li et al have designed SCs of penicillamine-protected Ag 14 NCLs and discussed the feasibility of proton conductivity across the -NH 3 + and -COO À ion pairs of the penicillamine ligands. 213 The Ag 14 NCL displayed a proton conductivity of 3.06 Â 10 À5 S cm À1 at 30 1C, which increased to 1.94 Â 10 À4 S cm À1 when the temperature was raised to 60 1C.…”