Organophosphorus Avenues toward Self‐Assembled Conjugated Soft Materials

Abstract

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.

An Unexpected “Step-Conjugated” Biphosphole via Unique P–P Bond Formation

“…1,12 Second, although not very pronounced, the peak positions are also quite close to those of 8, which by contrast shows two fairly pronounced absorption peaks at 315 and 365 nm. The latter peak coincides with the p-p* transition of previously studied dithienophosphole oxides, 3,12,13 suggesting a localized transition within this half of the molecule; the peak at 315 nm appears to originate from a localized transition likely involving the trivalent phosphole subunit.…”

“…Organophosphorus building blocks with highly desirable optoelectronic and morphological properties in particular have carved their own niche in this rapidly evolving field in recent years. [1][2][3][4] One of the most prominent examples of building blocks in this context is phosphole, a five-membered heterocycle. Although structurally similar to pyrrole, the properties of phosphole proved to be far from a simple analog of its nitrogen-based congener (Figure 1).…”

“…1 Our group and others have utilized these modifications to produce compounds that exhibit highly desirable properties in electronics, stimuli response, and self-organization. [1][2][3][4][6][7][8][9] At the same time, because of its conjugation with the p backbone, the exocyclic P-R moiety can affect the electronics of the system directly.…”

Phospholyl(borane) Amino Acids and Peptides: Stereoselective Synthesis and Fluorescent Properties with Large Stokes Shift

“…Furthermore, the introduction of phospholyl­(borane) amino acid residues in peptide chains offers the opportunity to direct the spatial orientation and the packing of these functional conjugated organophosphorus molecules , and thus, to tune the photophysical and electronic properties, making them well-suited for bioelectronic applications. As such, the self-assembly of these phospholes − appended with amino acid derivatives deserves further investigation and will be reported in due course.…”

Rich Coordination Chemistry of π-Acceptor Dibenzoarsole Ligands

“…As a consequence, these pyramidal heteroles are π-acceptor ligands because of the stabilization of the lowest unoccupied orbital (LUMO) levels . Despite the discovery of arsoles in the middle of the last century − and the possibility of utilizing the versatile Fagan–Nugent route, − only very few reports have dealt with the synthesis and characterization of these systems. − Phospholes, on the other hand, have received a great deal of attention over the past decade as interesting ligands for catalysis, coordination compounds, , and building blocks for supramolecular assemblies , but also as fascinating compounds for optoelectronic materials and organic electronic applications. ,− Common to all these phospholes is their facile derivatization, such as oxidation with chalcogens and their coordination to Lewis acids . Only very recently has some work discussing the optical properties of arsoles been published. − Remarkably, even reports of simple coordination compounds of arsoles are very rare. , Recently, very interesting examples of emissive and responsive arsole complexes have been reported. − Consequently, a deeper understanding of their coordination properties and their solid state packing motifs will be essential to tapping the full potential of this class of heavier group 15 heteroles as Lewis bases.…”