Superphenylphosphines: Nanographene-Based Ligands That Control Coordination Geometry and Drive Supramolecular Assembly

Abstract

Tertiary phosphines remain widely utilized in synthesis, most notably as supporting ligands in metal complexes. A series of triarylphosphines bearing one to three hexa-peri-hexabenzocoronene (HBC) substituents has been prepared by an efficient divergent route. These "superphenylphosphines", P{HBC(t-Bu)}Ph (n = 1-3), form the palladium complexes PdClL and PdClL where the isomer distribution in solution is dependent on the number of HBC substituents. The crystalline structures of five complexes all show intramolecular π-stacking between HBC-phosphines to form a supramolecular bidentate-like ligand that distorts the metal coordination geometry. When n = 2 or 3, the additional HBC substituents engage in intermolecular π-stacking to assemble the complexes into continuous ribbons or sheets. The phosphines adopt HBC's characteristics including strong optical absorption, green emission, and redox activity.

Synthesis of Cyclopenta‐HBCs and their Regioselective Chlorination During Oxidative Cyclodehydrogenation

“…HBC′s strong optical absorption and emission, as well as its multiple redox states were probed for a range of CpHBCs synthesised and compared to the HBC analogue 1 . Analysis of the cyclic voltammetric data (Table ) shows two pseudo‐reversible oxidations in the range of 0.9–1.3 V (vs. SCE), with 1 and 2 a exhibiting broadened voltammograms due to low solubility and electrode precipitation processes.…”

Boronate Covalent and Hybrid Organic Frameworks Featuring PIII and P=O Lewis Base Sites

“…The synthesis of boronated triphenylphosphine oxide precursor 4 involved the in situ Br/Li exchange/boronation of brominated precursor 3 using the protocol analogous to that described for 2 . Compound 3 was isolated as a yellow solid and characterized by 1 H, 11 B and 31 P NMR spectroscopy.…”

Diels–Alder Cycloaddition with CO, CO2, SO2, or N2 Extrusion: A Powerful Tool for Material Chemistry

“…Smith et al, described a series of triarylphosphines that bear large PAH substituents able of engaging in strong π-stacked interactions [ 256 ]. HBC-motif was introduced via Diels–Alder cycloaddition–Scholl dehydrocondensation sequences ( Scheme 206 ).…”

“… Superphenylphosphines synthesis: Diels–Alder cycloaddition (tetrarylcyclopentadienone as a diene), Scholl dehydrocondensation, reduction of P=O bond—an example [ 256 ]. Reagents and conditions: R = t -Bu; a = Ph 2 O, 250 °C, Y = 92%; b = next steps (Scholl dehydrocondensation).…”