Tuning of Cr-Cr Magnetic Exchange through Chalcogenide Linkers in Cr Molecular Dimers.

A set of three Cr-dimer compounds, Cr(en) (: S, Se; : Br, Cl; : ethylenediamine), with monoatomic chalcogenide bridges have been synthesized via a single-step solvothermal route. Chalcogenide linkers mediate magnetic exchange between Cr centers, while bidentate ethylenediamine ligands complete the distorted octahedral coordination of Cr centers. Unlike the compounds previously reported, none of the chalcogenide atoms are connected to extra ligands.

Add a Pinch of Tetrel: The Transformation of a Centrosymmetric Metal into a Nonsymmorphic and Chiral Semiconductor.

Centrosymmetric skutterudite RhP was converted to a nonsymmorphic and chiral compound RhSi P (space group P2 2 2 ) by means of partial replacement of Si for P. The structure, determined by a combination of X-ray crystallography and solid state P NMR, exhibits branched polyanionic P/Si chains that are unique among metal phosphides. A driving force to stabilize the locally noncentrosymmetric cis-RhSi P and fac-RhSi P fragments is π-electron back-donation between the Rh t -type orbitals and the unoccupied antibonding Si/P orbitals, which is more effective for Si than for P.

Unraveling the Origin of Photocatalytic Deactivation in CeO/NbO Heterostructure Systems during Methanol Oxidation: Insight into the Role of Cerium Species.

The study provides deep insight into the origin of photocatalytic deactivation of NbO after modification with ceria. Of particular interest was to fully understand the role of ceria species in diminishing the photocatalytic performance of CeO/NbO heterostructures. For this purpose, ceria was loaded on niobia surfaces by wet impregnation.

Centrosymmetric or Noncentrosymmetric? Transition Metals Talking in KTGeS(T = Co, Fe).

Two new quaternary sulfides KTGeS(T = Co, Fe) have been synthesized by a high-temperature solid-state routine and flux growth method. The crystal growth process of KTGeS(T = Co, Fe) was elucidated by powder X-ray diffraction and DSC thermal analysis. The millimeter-sized crystals of KTGeS(T = Co, Fe) were grown.

New Noncentrosymmetric Tetrel Pnictides Composed of Square-Planar Gold(I) with Peculiar Bonding.

Three novel isostructural equiatomic gold tetrel pnictides, AuSiAs, AuGeP, and AuGeAs, were synthesized and characterized. These phases crystallize in the noncentrosymmetric (NCS) monoclinic space group Cc (no. 9), featuring square-planar Au within cis-[AuTt Pn ] units (Tt=tetrel, Si, Ge; Pn=pnictogen, P, As).

Tuning Fe-Se Tetrahedral Frameworks by a Combination of [Fe(en)] Cations and Cl Anions.

A one-dimensional (1D) chain compound ( = ethylenediamine), featuring tetrahedral FeSe chains separated by [Fe(en)] cations and Cl anions, has been synthesized by a low temperature solvothermal method using simple starting materials. The degree of distortion in the Fe-Se backbone is similar to previously reported compounds with isolated 1D FeSe chains. Fe Mössbauer spectroscopy reveals the mixed-valent nature of [Fe(en)](FeSe)Cl with Fe centers in the [FeSe] chains and Fe centers in the [Fe(en)] complexes.