The self-assembly of 4-fold-symmetric porphyrins with Fe or Zn gave a new cubic ML cage framework with electron-deficient walls. This cage bound C-indene or C-anthracene bisadducts selectively, whereas unfunctionalized fullerenes and monoadducts were not encapsulated. The FeL cage also enabled the reaction of C and anthracene to yield the bisadducts selectively under conditions where no reaction was observed in the absence of the cage. These findings have relevance in the context of polymer solar cells, where C bisadducts have found use as electron acceptors, because these adducts currently require laborious and time-consuming syntheses and purification.

Size‐selective hydroformylation of terminal alkenes was attained upon embedding a rhodium bisphosphine complex in a supramolecular metal–organic cage that was formed by subcomponent self‐assembly. The catalyst was bound in the cage by a ligand‐template approach, in which pyridyl–zinc(II) porphyrin interactions led to high association constants (>10 5 m −1 ) for the binding of the ligands and the corresponding rhodium complex. DFT calculations confirm that the second coordination sphere forces the encapsulated active species to adopt the ee coordination geometry (i.e., both phosphine ligands in equatorial positions), in line with in situ high‐pressure IR studies of the host–guest complex. The window aperture of the cage decreases slightly upon binding the catalyst. As a result, the diffusion of larger substrates into the cage is slower compared to that of smaller substrates. Consequently, the encapsulated rhodium catalyst displays substrate selectivity, converting smaller substrates faster to the corresponding aldehydes. This selectivity bears a resemblance to an effect observed in nature, where enzymes are able to discriminate between substrates based on shape and size by embedding the active site deep inside the hydrophobic pocket of a bulky protein structure.

The versatility of nanographene (NG) as an electron donor is demonstrated when integrated together with an electron accepting porphycene into a novel electron NG hybrid. This feature is further exploited in dye-sensitized solar cells (DSSCs), in which photoanodes (ZnO) reveal a cascade of electron flow as modus operandi.

In the current work, we have explored a novel synthetic route towards metalated porphycenes and their use in p-type NiO-based dye-sensitized solar cells. Particular emphasis is placed on the influence that the relative positioning of the anchoring group exerts on the DSSC performance.Factors that favor dye-sensitized solar cells (DSSCs) as a key technology in solar-energy conversion schemes include low purity requirements and easy accessibility, low costs, fast processing, and simple up-scaling. DSSCs have been rendered even more attractive by recent progress in solid-state and flexible devices. 1,2 To date, record efficiencies as high as 13% have been reported for n-type DSSCs. 3 However, efficient p-type DSSCs, which complement n-type DSSCs in, for example, tandem configurations, are necessary for obtaining values beyond 13%, and are therefore the subject of intensive investigation. 4 Regardless of whether the semiconductor materials are n-or p-type, the chromophore attached to the semiconductor electrode is decisive in terms of light harvesting, charge transfer, and charge transport. Diverse organic or inorganic chromophores have recently been tested in both types of DSSCs. [5][6][7][8] Fine tuning synthetic parameters such as the metalation of the chromophore, the nature of the anchor, and the bridge that links the chromophore to the anchor, have made control over important characteristics like highly effective charge separation, reduced charge recombination, and long term stability possible. [9][10][11][12] Semiconductor nickel oxide (NiO) stands out as an electrode material for p-type DSSCs. 7,[13][14][15] This has triggered the design of novel light-harvesting and electron-accepting chromophores. 13 We have focused on porphycenes because of their similarity to porphyrins and phthalocyanines. 16,17 In contrast to the electrondonating features of porphyrins and phthalocyanines, which are widely used in n-type DSSCs, 8,18 porphycenes are strong electron acceptors, making them more suitable building blocks for p-type DSSCs. Only a few examples of the use of free-base porphycenes in solar energy devices are known to date. 19,20 We now report two major achievements. The first is the development of a new synthetic route to nickel porphycenes, which have barely been investigated previously. We have characterized the novel nickel porphycenes by physicochemical and computational techniques. Secondly, we have used these nickel porphycenes in p-type NiO-based DSSCs. We have been able to rationalize the overall performances in terms of the position and the nature of the anchor groups and, in turn, to establish new guidelines to designing novel electron acceptors.Three different nickel porphycenes were prepared -Scheme 1 -see ESI. † To obtain the target porphycenes, the 2,7,12,17-tetra-npropylporphycenato nickel (1) was chosen as starting material. Firstly, the peripheral alkyl chains ensure solubility in a wide variety of solvents. Secondly, the established chemistry of 1 allows the target featuring a vinyl group as a...

The most highly charged water‐soluble poly‐ortho‐substituted tetraarylporphycene (Pc8+) has been synthetized. The latter, which interacts in aqueous solutions with graphene oxide (GO) forming a photoactive ensemble Pc8+/GO, is immobilized by means of the Layer‐by‐Layer (LbL) technique onto ITO electrodes to afford novel solar energy conversion devices.