Triphenylamine-4-boronic acid | CAS 201802-67-7 | ≥98%

4-(Diphenylamino)phenylboronic acid (triphenylamine-4-boronic acid, 4-DPBA) is a triarylamine-functionalised arylboronic acid that allows installing a triphenylamine donor unit into extended conjugated architectures via palladium-catalysed Suzuki–Miyaura cross-coupling. The triphenylamine moiety is a propeller-like, nonplanar, electron-rich donor motif widely used in hole-transporting and emissive organic electronic materials; its geometry helps reduce close π-stacking and supports amorphous film-forming behaviour in suitably designed structures. These features underpin its use as a building block for electroluminescent oligomers and polymers, donor–acceptor dye-sensitised solar cell sensitisers, conjugated materials for OLED / OFET / OPV research, and solid-state blue emitter scaffolds.

The product may contain small amounts of the cyclic anhydride 4-(diphenylamino)phenylboroxine; under aqueous or basic coupling conditions the two forms re-equilibrate and the impact on yield is minor.

Applications and Reactions

• Suzuki–Miyaura coupling: participates as an electron-rich arylboronic acid coupling partner with aryl and heteroaryl halides under Pd catalysis to deliver biaryl products bearing the triphenylamine donor unit. The diphenylamino substituent strongly influences the electronic profile of the resulting biaryl, making the compound a documented reagent for constructing extended π-conjugated systems including biaryl, p-quaterphenyl, oligoarylene, and optoelectronic donor architectures.
• End-capping of oligofluorenes and related fluorene emitters for blue OLED / PLED materials: Suzuki cross-coupling at fluorene chain termini installs the diphenylamino group as a hole-transporting end-cap; this end-capping has been shown to lower the first ionisation potential, enhance thermal stability, and induce amorphous morphological stability of blue-emitting fluorene oligomers used in electroluminescent material research.
• Perylene dye functionalisation: Suzuki coupling of multi-brominated perylene monoimide cores with 4-(diphenylamino)phenylboronic acid affords tri- and tetra-(triphenylamine)-substituted perylene monoimides with broad absorption extending to ~750 nm; the corresponding perylene monoanhydrides have been applied as light-harvesting sensitisers in dye-sensitised solar cells, with the tetra-substituted derivative reported to give the highest power conversion efficiency within that family.
• Solid-state blue emitters with dimesitylboryl acceptors: Suzuki coupling installs the diphenylamino donor onto p-quaterphenyl frameworks laterally substituted with a bulky dimesitylboryl electron acceptor, generating twisted bipolar D–A architectures that exhibit intramolecular charge-transfer emission with large Stokes shift, suppressed solid-state π-stacking, high thermal stability, and bright blue fluorescence with high solid-state quantum yields — features that target solid-state blue emitter applications.
• Multiphoton blue photoluminescence and lasing materials: incorporation of diphenylamino end-caps into ladder-type oligo(p-phenylene) scaffolds has been reported to give exceptionally strong multiphoton-excited (from two- to five-photon) upconverted blue photoluminescence and efficient blue lasing behaviour, making this reagent relevant to rigid π-conjugated gain-media and nonlinear-optical photoluminescence studies.
• Suzuki polycondensation and end-capping for conjugated polymers (OLED / OFET / OPV): as a monofunctional arylboronic-acid building block or end-capper in suitably designed Suzuki polycondensation workflows, it introduces triphenylamine units into conjugated polymer backbones, side architectures, or chain termini. Triphenylamine-containing conjugated polymers exhibit p-type semiconducting and hole-transport behaviour and are investigated as active or transport layers in organic light-emitting diodes, organic field-effect transistors, and bulk-heterojunction organic photovoltaic devices.
• Protodeboronation and condition sensitivity: class-level arylboronic-acid chemistry. Stability under aqueous-basic coupling conditions is substituent-, pH-, base-, concentration-, and temperature-dependent; for electron-rich triarylamine-substituted substrates, reaction conditions should be selected for the specific coupling partner and exposure time, and slow-release boron formats can be considered when prolonged exposure to aqueous-basic conditions is required.
• Protected boronate ester forms: the corresponding pinacol ester is commercially documented (4-(diphenylamino)phenylboronic acid pinacol ester, CAS 267221-88-5) and provides an electron-rich protected boronate form for handling and Suzuki–Miyaura coupling workflows. Other slow-release boron formats, including MIDA boronates and potassium organotrifluoroborates, are class-level protection strategies for chromatographic handling, prolonged shelf stability, or controlled-release coupling behaviour; preparation of triphenylamine variants of these formats should be confirmed against substrate-specific procedures when needed.

Further Reading

For comprehensive protocols on boronic acids, esters, protodeboronation, boroxine content, and reagent selection, refer to NorrChemica's Lab Journal guide: Choosing Your Boron Source for Suzuki–Miyaura Coupling.