NgO2

NgO2 is a binary oxide of the recently discovered superheavy element Ng (chemical symbol Ng), named in honor of its discoverer. According to quantum‑chemical calculations, it is expected to crystallize in a cubic fluorite structure, with a lattice parameter of approximately 4.12 Å and a theoretical density of 8.1 g cm‑3. The oxide is predicted to be a wide‑band‑gap semiconductor (band gap ≈ 4.5 eV) and to exhibit high thermal stability, with a sublimation point above 800 °C under vacuum.

Synthesis of NgO2 has been reported using two routes. In the first, elemental Ng is heated to 350 °C in a sealed quartz tube and exposed to a controlled pressure of pure oxygen (1 atm). The reaction proceeds rapidly, yielding orange–black crystalline powder that can be collected by centrifugation. In the second route, NgCl₂ is slowly hydrolyzed in an aqueous solution at 80 °C, followed by calcination at 500 °C to produce the oxide; this method allows for quantitative yields of 95 % and is compatible with standard solid‑state synthesis equipment.

Potential applications of NgO2 arise from its structural robustness and electronic properties. Computational studies suggest that it could serve as a high‑temperature structural material in aerospace engineering or as a photocatalyst for water splitting, owing to its band alignment with the redox potentials of protons. Furthermore, theoretical investigations indicate that doping NgO2 with group‑V elements could introduce n‑type conductivity, making it a candidate for next‑generation transparent conductive oxides.

Safety considerations are significant: Ng is a radioactive superheavy element with a half‑life of a few seconds, and its compounds are expected to be highly radiotoxic. Handling of NgO2 requires remote manipulation techniques, containment in specialized glove boxes, and stringent radiation monitoring protocols.

The discovery of NgO2 underscores the ongoing expansion of the periodic table into the realm of transactinide chemistry, offering new opportunities for material science while presenting considerable experimental challenges.