Dimensional reduction by geometrical frustration in a cubic antiferromagnet composed of tetrahedral clusters

Dimensionality is a critical factor in determining the properties of solids and is an apparent built-in character of the crystal structure. However, it can be an emergent and tunable property in geometrically frustrated spin systems. Here, we study the spin dynamics of the tetrahedral cluster antiferromagnet, pharmacosiderite, via muon spin resonance and neutron scattering. We find that the spin correlation exhibits a two-dimensional characteristic despite the isotropic connectivity of tetrahedral clusters made of spin 5/2 Fe3+ ions in the three-dimensional cubic crystal, which we ascribe to two-dimensionalisation by geometrical frustration based on spin wave calculations. Moreover, we suggest that even one-dimensionalisation occurs in the decoupled layers, generating low-energy and one-dimensional excitation modes, causing large spin fluctuation in the classical spin system. Pharmacosiderite facilitates studying the emergence of low-dimensionality and manipulating anisotropic responses arising from the dimensionality using an external magnetic field.

Heterometallic Re/Mo and Re/W cubane-type cluster complexes

A series of heterometallic tetrahedral cluster complexes with the general formula [{MxRe4-xSe4}(CN)12]n– (M = Mo, W; x = 2, 3) was obtained using the reactions ReI3, MO3 with selenium and...

Imidazolium salts and [Pt(cod)2]: from NHC hydrido complexes to the unprecedented olefinic tetrahedral cluster [Pt4(μ-H)(cod)4]BF4

Whereas the bis(imine)imidazolium salt 1·Cl yielded with [Pt(cod)2] the PtII-hydrido NHC complex 3, the unprecedented, tetrahedral cluster [Pt4(μ-H)(cod)4]BF4 (7) was unexpectedly obtained from 1·BF4.

Atomistic investigation of hybrid plasmonic systems

By using time-dependent density functional theory, we investigate in a fully quantum mechanical framework the interactions, in an ultra-near-field regime, between a localized surface plasmon excitable in a silver tetrahedral cluster and a molecular exciton with excitation energy in the same range. We show that, for metal–molecule distances below 5 Å, the optical response of the system results characterized by the appearance of a double peak structure. We analyze the transition densities for the resonant energies and propose a plasmon–exciton electromagnetic interaction model to explain the emerging of a lower energy resonance in the spectra of such kind of hybrid systems of interest for molecular plasmonics.

A cationic tetrahedral Zn(ii) cluster based on a new salicylamide imine multidentate ligand: synthesis, structure and fluorescence sensing study

We present here a monocationic ZnII tetrahedral cluster which is extremely stable and exhibits highly sensitive and selective recognition of phosphates against other common anions in water containing media.