Synthesis, characterization and chemical bonding analysis of the quaternary cyanamides LiMnHf(NCN) and LiMnZr(NCN).

LiMnHf(NCN) and LiMnZr(NCN) were prepared solid-state metathesis reactions either a more exothermic direct reaction between LiNCN, MnCl and HfCl or a milder two-step reaction in which ternary LiZr(NCN) was first prepared and subsequently reacted with MnF. Their crystal structures were determined from powder X-ray diffraction data and found to crystallize isotypically in low-symmetry variants of the [NiAs]-type MNCN structure with 3̄1 symmetry and comprise corundum-like [(NCN)] layers ( = Hf, Zr) alternating with [LiMn(NCN)] layers. In-depth chemical bonding analysis was undertaken using LOBSTER to calculate the Löwdin charges which reveal significant differences in covalency between the two metal layers that is also reflected in the crystal orbital bond indices (COBI) of the metal-nitrogen bonds as well as the carbon-nitrogen bonds that show distinct single and triple bond character, which is also evident from infrared spectroscopy measurements.

Perovskite-Like Carbodiimides (NCN): Synthesis and Characterization of MnHf(NCN) and FeHf(NCN).

Two novel ternary air-stable transition-metal carbodiimides, MnHf(NCN) and FeHf(NCN), were synthesized via solid-state metathesis using either ZnNCN or NaNCN as the carbodiimide source and the corresponding binary metal chlorides. These two phases are the first examples of transition-metal carbodiimides with an (NCN) composition, akin to ubiquitous O perovskite oxides. The crystal structure of MnHf(NCN) was determined and refined from powder X-ray diffraction (XRD) data in the non-centrosymmetric space group 622 allowing for chirality, the assignment of which is supported by second-harmonic generation (SHG) measurements.

Dehydrogenative C-H Phenochalcogenazination.

Heavy-atom-modified chalcogen-fused triarylamine organic materials are becoming increasingly important in the photochemical sciences. In this context, the general and direct dehydrogenative C-H phenochalcogenazination of phenols with the heavier chalcogens selenium and tellurium is herein described. The latter dehydrogenative C-N bond-forming processes operate under simple reaction conditions with highly sustainable O serving as the terminal oxidant.