A new angle: The insertion of a 2,2′‐biphosphole subunit into π‐conjugated systems offers a new way to control the HOMO–LUMO gap. Tuning of the dihedral angle (θ) between the two phosphorous heterocycles, either by metal coordination or covalent bonding through the P substitution can lead to control of the band gap. These new π‐conjugated systems can be used as emitting materials in white organic light‐emitting devices (WOLEDs).

A new, highly adaptable type of phosphinamide‐based hydrogen bonding is representatively demonstrated in π‐conjugated phosphole materials. The rotational flexibility of these intermolecular P=O−H−N hydrogen bonds is demonstrated by X‐ray crystallography and variable‐concentration NMR spectroscopy. In addition to crystalline compounds, phosphinamide hydrogen bonding was successfully introduced into the self‐assembly of soft crystals, liquid crystals, and organogels, thus highlighting the high general value of this type of interaction for the formation of organic soft materials.

The synthesis of a p-conjugated organophosphorus species with bridging P-P unit is reported. Because of the pyramidal geometry of the phosphorus centers, the molecular scaffold provides intriguing electronic communication throughout the three-dimensional structure via p-s-p conjugation in stepwise fashion. The dimeric species was serendipitously found to be accessible via a reaction of the corresponding P-amino-phosphole precursor through mediation with the hard Lewis acid BF 3 . We provide detailed mechanistic studies toward a suitable reaction mechanism that was also verified via computational means. Moreover, we elaborate the utility of the biphosphole via phosphorus functionalization that lends further proof for the step conjugation provided by the unique phosphorus-based molecular architecture.

The discovery and molecular engineering of novel electroluminescent materials is still a challenge in optoelectronics. In this work, the development of new π-conjugated oligomers incorporating a dihydrophosphete skeleton is reported. Variation of the substitution pattern of 1,2-dihydrophosphete derivatives and chemical modification of their P atoms afford thermally stable derivatives, which are suitable emitters to construct organic light-emitting diodes (OLEDs). The optical and electrochemical properties of these new P-based oligomers have been investigated in detail and are supported by DFT calculations. The OLED devices exhibit good performance and current-independent CIE coordinates.

Self-assembly is nature's most powerful tool for constructing the physical world. Self-assembly has also become an important theme in organic materials research. Within our research program on π-conjugated organophosphorus materials, we have recently aimed to combine the unique optoelectronic properties of organophosphorus building blocks with self-assembly features. Our novel organophosphorus-based chromophore mesogens self-assemble into complex structures, such as liquid crystals and organogels. More importantly, intriguing optoelectronic properties not present in the original building blocks are also produced as a result. These results have opened up a rich chemistry toward smart functional materials that is currently being further exploited in our group.