This work showcases chiral complementarity in aromatic stacking interactions as an effective tool to optimize the chiroptical and electrochemical properties of perylene diimides (PDIs). PDIs are a notable class of robust dye molecules and their rich photo- and electrochemistry and potential chirality make them ideal organic building blocks for chiral optoelectronic materials. By exploiting the new bay connectivity of twisted PDIs, a dynamic bis-PDI macrocycle (the “Pink Box”) is realized in which homochiral PDI–PDI π–π stacking interactions are switched on exclusively. Using a range of experimental and computational techniques, we uncover three important implications of the macrocycle’s chiral complementarity for PDI optoelectronics. First, the homochiral intramolecular π–π interactions anchor the twisted PDI units, yielding enantiomers with half-lives extended over 400-fold, from minutes to days (in solution) or years (in the solid state). Second, homochiral H-type aggregation affords the macrocycle red-shifted circularly polarized luminescence and one of the highest dissymmetry factors of any small organic molecule in solution ( g lum = 10 –2 at 675 nm). Finally, excellent through-space PDI–PDI π-orbital overlap stabilizes PDI reduced states, akin to covalent functionalization with electron-withdrawing groups.

The confinement of phosphines within micro- or nano-environments influences not only their behaviour but also that of their metal complexes. The influence of environment on this reactivity is reviewed and future challenges identified.

A series of ethane‐dithiolate (edt = S(CH2)2S) complexes [Fe2(CO)5(EPh3)(µ‐edt)] and [Fe2(CO)4(EPh3)2(µ‐edt)] (E = P, As, Sb), biomimics of the core of [FeFe]‐hydrogenases, have been prepared and structurally characterised. The introduced ligand(s) occupies apical sites lying trans to the iron‐iron bond. NMR studies reveal that while in the mono‐substituted complexes the Fe(CO)3 moiety undergoes facile trigonal rotation, the Fe(CO)2(PPh3) centres do not rotate on the NMR timescale. The reductive chemistry has been examined by cyclic voltammetry both in the presence and absence of CO and the observed behavior is found to be dependent upon the nature of the substituents. With L = CO or SbPh3 potential inversion is seen leading to a two‐electron reduction, while for others (L = PPh3, AsPh3) a quasi‐reversible one‐electron reduction is observed. Protonation studies reveal that [Fe2(CO)5(PPh3)(µ‐edt)] is only partially protonated by excess HBF4·Et2O, thus ruling complexes [Fe2(CO)5(EPh3)(µ‐edt)(µ‐H)]+ out as a catalytic intermediates, but [Fe2(CO)4(PPh3)2(µ‐edt)] reacts readily with HBF4·Et2O to produce [Fe2(CO)4(PPh3)2(µ‐edt)(µ‐H)]+. While all new complexes are catalysts for the reduction of protons in MeCN, their poor stability and relatively high reduction potentials does not make them attractive in this respect.

[FeFe]-ase biomimics containing a redox-active ferrocenyl diphosphine have been prepared and their ability to reduce protons and oxidise H2 studied, including 1,1’-bis(diphenylphosphino)ferrocene (dppf) complexes Fe2(CO)4(-dppf)(-S(CH2)nS) (n = 2, edt; n...