Owing to the difficulty in acquiring compounds with combined high energy bandgaps and lower‐lying intramolecular charge‐transfer excited states, the development of ultraviolet (UV) thermally activated delayed fluorescence (TADF) materials is quite challenging. Herein, through interlocking of the diphenylsulfone (PS) acceptor unit of a reported deep‐blue TADF emitter (CZ‐PS) by a dimethylmethylene bridge, CZ‐MPS, a UV‐emissive TADF compound bearing a shallower LUMO energy level and a more rigid structure than those of CZ‐PS is achieved. This represents the first example of a UV‐emissive TADF compound. Organic light‐emitting diode (OLED) using CZ‐MPS as the guest material can emit efficient UV light with emission maximum of 389 nm and maximum total external quantum efficiency (EQEmax) of 9.3%. Note that this EQEmax value is twice as high as the current record EQEmax (4.6%) for UV‐OLEDs. This finding may shed light on the molecular design strategy for high‐performance UV‐OLED materials.

R-Fe 2 O 3 nanoparticulate films could be formed on the surface of R-Fe 2 O 3 hydrosol after aging of the hydrosol or by compressing of the nanoparticles on the sol surface, in which a three-dimensional ordered structure was constructed by the Langmuir-Blodgett technique and colloid chemical methods. The structure of the LB film was characterized by AFM, TEM, XPS, and UV-vis spectra and small-angle X-ray diffraction. Gas-sensing measurement shows that the LB film has good sensitivity to alcohols at room temperature.