Wojciech Wegner

Facile formation of thermodynamically unstable novel borohydride materials by a wet chemistry route.

A novel wet synthetic method utilizing weakly coordinating anions that yields LiCl-free Zn-based materials for hydrogen storage has recently been reported. Here we show that this method may also be applied for the synthesis of the pure yttrium derivatives, M[Y(BH4)4] (M = K, Rb, Cs). Moreover, it can be extended to the preparation of previously unknown thermodynamically unstable derivatives, Li[Y(BH4)4] and Na[Y(BH4)4]. Importantly, these two H-rich phases cannot be accessed by standard dry (mechanochemical) or solid/gas synthetic methods due to the thermodynamic obstacles. Here we describe their crystal structures and selected important physicochemical properties.

Ferromagnetic ground state for a hypothetical iron-based extended metal atom chain

AbstractTheoretical calculations for the first tri-iron-based extended metal atom chain (EMAC) molecule are reported. The studied triple-high-spin (S = 6) complex exhibits ferromagnetic ordering (according to Ising and spin-projection approximations), which renders it unique among all previously prepared and theoretically calculated EMAC compounds. This ordering originates from the prevailing ferromagnetic nearest-neighbor interactions, while the magnetic superexchange between terminal Fe2+ sites is weaker and antiferromagnetic. Calculations indicate that this linear chain system based on a tri-iron core shows potential for the development of spin-frustrated behavior, which could be achieved through rational modification of the equatorial and axial ligands. Graphical abstractEffect of d(z2) orbital occupancy on central Fe(II) on spin orientations on termianal Fe(II) ions in extended metal atom chain