Multinary transition metal nitrides and oxonitrides are a versatile and intriguing class of compounds. However, they have been investigated far less than pure oxides. The compounds Sc 5 P 12 N 23 O 3 and Ti 5 P 12 N 24 O 2 have now been synthesized from the binary nitrides ScN and TiN, respectively, by following a high-pressure high-temperature approach at 8 GPa and 1400 °C. NH 4 F acts as a mineralizing agent that supports product formation and crystallization. The starting materials ScN and TiN are seemingly an uncommon choice because of their chemical inertness but, nevertheless, react under these conditions. Sc 5 P 12 N 23 O 3 and Ti 5 P 12 N 24 O 2 crystallize isotypically with Ti 5 B 12 O 26 , consisting of solely vertex-sharing P(O/N) 4 tetrahedra forming two independent interpenetrating diamond-like nets that host TM(O/N) 6 (TM = Sc, Ti) octahedra. Ti 5 P 12 N 24 O 2 is a mixedvalence compound and shows ordering of Ti 3 + and Ti 4 + ions.

The new semiconducting sodalite-type BaGe8As14 compound exhibits a narrow band gap, low resistivity and partially disordered atom positions as good prerequisites for a thermoelectric material.

The three‐dimensional SiP4 network in the known phosphidosilicate Ba2SiP4‐tI28 is analogous to β‐Cristobalite if oxygen is formally replaced by P–P dimers. Here we report a second polymorph Ba2SiP4‐oP56 [Pnma, a = 12.3710(4) Å, b = 14.6296(7) Å, c = 7.9783(3) Å; Z = 8] with chains of SiP4 tetrahedra connected by P–P bonds, reminiscent to the elusive fibrous SiO2. Ba2SiP4 is enantiotropic. The high temperature polymorph Ba2SiP4‐oP56 transforms to the low‐temperature phase Ba2SiP4‐tI28 at 650 °C and reconstructs to the high‐temperature modification at 1100 °C. DFT calculations predict an indirect optical bandgap of about 1.7 eV.

TiP4N8 was obtained from the binary nitrides TiN and P3N5 upon addition of NH4F as a mineralizer at 8 GPa and 1400 °C. An intricate interplay of disorder and polymorphism was elucidated by in situ temperature‐dependent single‐crystal X‐ray diffraction, STEM‐HAADF, and the investigation of annealed samples. This revealed two polymorphs, which consist of dense networks of PN4 tetrahedra (degree of condensation κ=0.5) and either augmented triangular TiN7 prisms or triangular TiN6 prisms for α‐ and β‐TiP4N8, respectively. The structures of TiP4N8 exhibit body‐centered tetragonal (bct) framework topology. DFT calculations confirm the measured band gaps of α‐ and β‐TiP4N8 (1.6–1.8 eV) and predict the thermochemistry of the polymorphs in agreement with the experiments.

FeFe(Cl 2 -bdt)(CO) 6 ]( 1;C l 2 -bdt = 3,6-dichlorobenzene-1,2-dithiolate), inspired by the actives ite of FeFe-hydrogenase, shows ac hemically reversible 2e À reduction at À1.20 Vv ersus the ferrocene/ferrocenium couple. The rigid and aromatic bdt bridging ligand lowers the reductionp otential and stabilizes the reduced forms,c ompared with analogous complexes with aliphatic dithiolates;t husa llowing detailso ft he catalytic process to be characterized.Herein,t ime-resolved IR spectroscopy is used to provide kinetic and structurali nformation on key catalytic intermediates. This includes the doublyr educed, protonated complex 1H À ,w hich has not been previously identifiede xperimentally.I na ddition, the first direct spectroscopic observation of the turnoverp rocess for am olecular H 2 evolving catalysti s reported, allowing for straightforward determination of the turnover frequency.Supporting information and the ORCID identification number(s) for the author(s) of this article can be found under: https://doi.