Search

A new family of molecules obtained by coupling Tröger’s base unit with dicyanovinylene-terminated oligothiophenes of different lengths has been synthesized and characterized by steady-state stationary and transient time-resolved spectroscopies. Quantum chemical calculations allow us to interpret and recognize the properties of the stationary excited states as well as the time-dependent mechanisms of singlet-to-triplet coupling. The presence of the diazocine unit in Tröger’s base derivatives is key to efficiently producing singlet-to-triplet intersystem crossing mediated by the role of the nitrogen atoms and of the almost orthogonal disposition of the two thiophene arms. Spin–orbit coupling-mediated interstate intersystem crossing (ISC) is activated by a symmetry-breaking process in the first singlet excited state with partial charge transfer character. This mechanism is a characteristic of these molecular triads since the independent dicyanovinylene-oligothiophene branches do not display appreciable ISC. These results show how Tröger’s base coupling of organic chromophores can be used to improve the ISC efficiency and tune their photophysics.

The rise of antibiotic-resistant bacteria has created an urgent need for antibacterial materials. One of the most widespread strategies involves the covalent attachment of ionic moieties, which can, however, compromise the quality of the final polymers. Herein, we report the synthesis of ionic covalent organic framework nanoparticles via click postsynthetic modification. The material is highly dispersible and exhibits excellent antibacterial properties against both Gram-positive and Gram-negative bacteria. Furthermore, biobased polymer/COF nanocomposites were produced through casting/melt compression and melt electrospinning, retaining the antibacterial properties without sacrificing the thermal stability of the polymers. Ongoing studies in our laboratories are exploring the potential application of these composites in biomedical devices.

In order to introduce the concept of covalent organic frameworks (COFs), an important class of predictable crystalline porous polymers, an integrated laboratory experiment for advanced organic chemistry students is reported. The importance of these kind of polymers and their multiple applications are presented as a part of key concepts in polymer and organic chemistry, bridging these disciplines to materials science. Students carry out the synthesis and characterization of an imine-linked COF and its building blocks. The polymer is formed at room temperature by using solvent-assisted synthesis and mechanochemistry. Students are trained in solid state characterization techniques, including FTIR spectroscopy, thermogravimetric analysis (TGA), 13C NMR cross-polarization–magic angle spinning (CP-MAS) NMR spectroscopy, and powder X-ray diffraction (PXRD), which are essential in the important field of reticular chemistry. Therefore, this lab experience constitutes a practical introduction to COFs.

Three new hexaazatriphenylene (HAT)-based electron-accepting molecules with octupolar disc-like symmetry that combine the HAT core with six branches of electron-donor thiophenes in two modalities have been synthesized: (i) with six donor thiophenes and bithiophenes delineating a six-donor-to-one-acceptor (6–1) profile and (ii) with six donor–acceptor branches configuring a 6–6–1 acceptor–donor–acceptor triad. The 6-fold accumulation of donors and acceptors in the periphery of the HAT core is expected to tune the molecular electronic and optical properties. An exhaustive analysis of these properties as a function of the 6–1 and 6–6–1 stoichiometry of the molecules is described by combining a palette of experimental spectroscopic techniques such as electronic absorption (from the ground electronic and excited states), emission (fluorescence and phosphorescence), ultraviolet photoelectron spectroscopy, spectroelectrochemistry, and vibrational Raman have been implemented, all combined with electrochemistry and molecular theoretical modeling. A particular focus on the charged species and the charge distribution around the 6–1 and 6–6–1 patterns is conducted. Structure–property relationships have been outlined. The complete understanding of all these properties might help to design improved chromophores based on the HAT structure and to anticipate new properties.

Perylene bisimides (PBIs) are n-type semiconducting and photogenerating materials widely used in a variety of optoelectronic devices. Particularly interesting are PBIs that are simultaneously water-soluble and liquid-crystalline (PBI-W+LC) and, thus, attractive for the development of high-performing easily processable applications in biology and “green” organic electronics. In this work, singular temperatures connected to charge transport mechanism transitions in a PBI-W+LC derivative are determined with high accuracy by means of temperature-dependent photocurrent studies. These singular temperatures include not only the ones observed at 60 and 110 °C, corresponding to phase transition temperatures from crystalline to liquid-crystalline (LC) and from LC to the isotropic phase, respectively, as confirmed by differential scanning calorimetry (DSC), but also a transition at 45 °C, not observed by DSC. By analyzing the photocurrent dependence simultaneously on temperature and on light intensity, this transition is interpreted as a change from monomolecular to bimolecular recombination. These results might be useful for other semiconducting photogenerating materials, not necessarily PBIs or even organic semiconductors, which also show transport behavior changes at singular temperatures not connected with structural or phase transitions.

Perylene bisimide (PBI) derivatives are n-type semiconductor materials widely used in a variety of optoelectronic devices. Great efforts have been devoted to the synthesis of soluble PBIs to allow processing by inexpensive solution-state methods. Recently, water-soluble compounds are receiving special attention for their potential in the fields of biology and “green” organic electronics. There is also a growing interest in the development of liquid crystalline PBIs, in order to improve the supramolecular organization and hence the transport performance. This work reports the first investigation of the mobility measured by the time-of-flight technique and the photoconductive response of the perylene derivative N,N′-bis[1-(2,5,8,11-tetraoxadodec-1-yl)-3,6,9,12-tetraoxatridec-1-yl]-perylene-3,4:9,10-bis(dicarboximide) (PBI-W), which is simultaneously water-soluble and liquid-crystalline. For comparison purposes, a parallel investigation with the commercial derivative N,N′-bis(1-hexylheptyl)-perylene-3,4:9,10-bis(dicarboximide) (PBI-C6), which is neither liquid-crystal nor water-soluble, has also been carried out. The conductive spectral response and the mobility dependence on the strength of the applied electric field were studied in order to optimize mobility measurements conditions. The mobility was determined as a function of temperature from room temperature (22 °C) up to 100 and 120 °C, for PBI-W and PBI-C6, respectively. Results are discussed in correlation with the crystalline or liquid-crystalline character phase of the material.

Here we present the synthesis and optical and structural characterization of a new series of alternating donor–acceptor copolymers based on 3,4-ethylenedioxythiophene (EDOT). The donor consists of phenylene, alkylated fluorene, or diethynyl-1,4-phenylene as the aryl units copolymerized with the EDOT group with and without a 9,10-anthraquinone (AQ) side chain as the acceptor group, namely, as PEX-AQand PEX, respectively. The changes in the electronic absorption/emission spectra and redox properties are analyzed in detail as a function of (i) the composition of the copolymers and (ii) the inclusion of the pendant 9,10-anthraquinone. Density functional theory calculations are used to interpret the experimental results. Special emphasis is placed on the flexibility of the phenylene-based copolymer spine which favors the tendency toward aggregation and confers interesting solvathocromic, thermochromic, and sonochromic properties when applying external stimuli. This is explained by means of an order–disorder conformational transformation (driven by π–π stacking) in solution upon ultrasonication, temperature changes, and the nature of the solvents. A comparison of the transient triplet–triplet absorption spectra of the phenylene-based PEBcopolymer in the unaggregated and aggregated forms reveals the formation of accessible triplet excited states whose nature is discussed in connection with the molecular flexibility of the copolymer backbone. These studies highlight the relevance of the precise control of the polymer architecture (donor–acceptor strategy in PEXversus double-cable concept in PEX-AQ) for suitable tunability of the optical and electronic properties of processable conjugated polymers for organic electronics.

Four new HAT derivatives with octupolar symmetry have been synthesized. Their linear and nonlinear optical, photophysical, and electrochemical properties have been rationalized in terms of donor–acceptor interactions. We get further insights in the relationship between experimental first hyperpolarizability and two-photon absorption cross section: the δ/β ratio is connected with the electron donor–acceptor strength between the HAT core and the peripheral groups but also with the ethylene/acetylene bridges. This structure–property relationship can be used to design octupoles with more efficient nonlinear responses. A HAT derivative based on the fusion of three HAT cores and without any defined donor–acceptor pattern is studied in comparison with the charge transfer HAT versions. A complete study of the electronic structure of the five molecules in the context of the origin of the relevant optical properties is carried out combining several spectroscopic techniques and quantum chemistry.

Graphene flakes covalently modified with a conjugated polymer, poly[(9,9‐dihexylfluorene)‐co‐alt‐(9,9‐bis‐(6‐azidohexyl)fluorene)] (PFA), were efficiently synthesised by a Cu‐catalysed Huisgen 1,3‐dipolar cycloaddition between alkyne‐modified graphene and an azide‐functionalised polymer. Two approaches for the modification of graphene with alkyne groups were investigated (coupling with a diazonium salt generated in situ or an amidation reaction) and the optimum conditions determined. The success of the click‐coupling approach was confirmed by FTIR, 1H NMR, Raman, and X‐ray photoelectron spectroscopy (XPS). The absorption and emission spectra of the click product show a strong solvent dependency.

Herein, we report a new family of naphthaleneamidinemonoimide‐fused oligothiophene semiconductors designed for facile charge transport in organic field‐effect transistors (OFETs). These molecules have planar skeletons that induce high degrees of crystallinity and hence good charge‐transport properties. By modulating the length of the oligothiophene fragment, the majority carrier charge transport can be switched from n‐type to ambipolar behavior. The highest FET performance is achieved for solution‐processed films of 10‐[(2,2′‐bithiophen)‐5‐yl]‐2‐octylbenzo[lmn]thieno[3′,4′:4,5]imidazo[2,1‐b][3,8]phenanthroline‐1,3,6(2 H)‐trione (NDI‐3 Tp), with optimized film mobilities of 2×10−2and 0.7×10−2cm2V−1s−1for electrons and holes, respectively. Finally, these planar semiconductors are compared with their twisted‐skeleton counterparts, which exhibit only n‐type mobility, in order to understand the origin of the ambipolarity in this new series of molecular semiconductors.

A new hexaazatriphenylene (HAT) derivative formed by the fusion of three HAT units has been prepared and its electronic and molecular structures have been fully characterized by optical and vibrational Raman spectroscopy, electrochemistry, solid‐state UV and inverse photoemission spectroscopy (UPS and IPES), and by quantum‐chemical calculations. A comparative HAT versus tri‐HAT study was performed. The fusion of three HAT molecules causes modifications in the optical and electrochemical properties consistent with enhanced π‐electron delocalization attained in a bigger planar core. Such combined experimental and theoretical studies are useful to balance chemical design with supramolecular engineering directed to find enhanced characteristics for new organic semiconductor applications.

The presence of amplified spontaneous emission (ASE) by optical pump in polystyrene films doped with N,N′-di(10-nonadecyl)perylene-3,4:9,10-tetracarboxylic diimide (PDI-N) in a range of PDI-N concentrations between 0.25 and 5 wt. % is reported. Gain coefficients up to 10 cm^−1, at a pump intensity of 74 kW/cm^2, were obtained. The lowest thresholds (∼15 kW/cm^2) and largest photostabilities measured at 50% (∼50 min, i.e., 30,000 pump pulses) were obtained for concentrations up to 1 wt. %. The observation of an increase in the ASE threshold and a decrease in the photostability for larger concentrations is attributed to the presence of aggregated species.

Two triads (donor–spacer–acceptor), exTTF–BN–C60(6) and ZnP–BN–C60(7), in which electron donors (i.e., exTTF or ZnP) are covalently linked to C60through a chiral binaphthyl bridge (BN), have been prepared in a multistep synthetic procedure starting from a highly soluble enantiomerically pure binaphthyl building block (1). Unlike other oligomeric bridges, with binaphthyl bridges, the conjugation between the donor and the acceptor units is broken and geometric conformational changes are facilitated. Consequently, distances and electronic interactions between the donor and C60are drastically changed. Both donor–spacer–acceptor (D–s–A) systems (i.e., 6and 7) exhibit redox processes that correspond to all three constituent electroactive units, namely, donor, BN, and C60. Appreciable differences were, however, observed when comparing triad 6, in which no significant exTTF–C60interactions were noted, with D–s–A 7, whose geometry favors donor–acceptor and π–π interactions that result in ZnP–C60electronic communication. This through‐space interaction is, for example, reflected in the redox potentials. Excited‐state studies, carried out by fluorescence and transient absorption spectroscopy, also support through‐space rather than through‐bond interactions. Although both triads form the corresponding radical‐ion pair, that is, exTTF.+–BN–C60.−and ZnP.+–BN–C60.−, dramatic differences were found in their lifetimes: 165 μs and 730 ns, respectively.

A series of donor–acceptor arrays (C60–oligo‐PPV–exTTF; 16–20) incorporating π‐conjugated oligo(phenylenevinylene) wires (oligo‐PPV) of different length between π‐extended tetrathiafulvalene (exTTF) as electron donor and C60as electron acceptor has been prepared by multistep convergent synthetic approaches. The electronic interactions between the three electroactive species present in 16–20were investigated by UV‐visible spectroscopy and cyclic voltammetry (CV). Our studies clearly show that, although the C60units are connected to the exTTF donors through a π‐conjugated oligo‐PPV framework, no significant electronic interactions are observed in the ground state. Interestingly, photoinduced electron‐transfer processes over distances of up to 50 Å afford highly stabilized radical ion pairs. The measured lifetimes for the photogenerated charge‐separated states are in the range of hundreds of nanoseconds (∼500 ns) in benzonitrile, regardless of the oligomer length (i.e., from the monomer to the pentamer). A different lifetime (4.35 μs) is observed for the heptamer‐containing array. This difference in lifetime has been accounted for by the loss of planarity of the oPPV moiety that increases with the wire length, as established by semi‐empirical (PM3) theoretical calculations carried out with 19and 20. The charge recombination dynamics reveal a very low attenuation factor (β=0.01±0.005 Å−1). This βvalue, as well as the strong electron coupling (V∼5.5 cm−1) between the donor and the acceptor units, clearly reveals a nanowire behavior for the π‐conjugated oligomer, which paves the way for applications in nanotechnology.

Novel photo‐ and electroactive triads, in which π‐conjugated p‐phenylenevinylene oligomers (oPPVs) of different length are connected to a photoexcited‐state electron donor (i.e., zinc tetraphenylporphyrin) and an electron acceptor (i.e., C60), were designed, synthesized, and tested as electron‐transfer model systems. A detailed physicochemical investigation, concentrating mainly on long‐range charge separation and charge recombination and kinetics, revealed small attenuation factors βof 0.03±0.005 Å−1. Energy matching between the HOMO levels of C60and oPPVs emerged as a key parameter for supporting molecular‐wire‐like behavior: It favors rapid and efficient electron or hole injection into the oPPV wires. Large electronic coupling values were determined as a result of paraconjugation in the oPPV moieties.

This tutorial reviewsurveys recent advances in the field of C60π-conjugated oligomer donor–acceptor ensembles. In particular, different synthetic strategies are discussed that were developed to link π-conjugated oligomers, as versatile photoexcited state electron donors, to C60. We highlight relationships between the naturestructural aspects of π-conjugated donor systems and a variety of physico-chemical features. Modifications of the oligomeric components are discussed under aspects of tailoring i the absorption cross-section of the chromophore in the visible region, ii the oxidation potential of the oligomeric donor moiety, iii the size, shape, or chemical makeup of the oligomer, and iv the stabilization of the charge-separated radical ion pairs. In the final section, the applicability of selected materials for the fabrication of photovoltaic devices is analyzed.

The synthesis and characterization of a new series of substituted polythiophenes containing an electron acceptor anthraquinone moiety in the side chain are reported. The acceptor molar content was varied by the co-polymerization of both alkylthiophene and thiophene bearing anthraquinone monomers in different ratios. NMR analysis shows a good correlation between the monomer feed composition at the beginning of the polymerization and the actual unit composition of the backbone. The conjugation length and the chemical composition of the copolymers as a function of the molecular weight have been studied by size exclusion chromatography. Small angle X-ray scattering and UV-Vis absorption spectra have been used to monitor the degree of order and chain organization in the solid state. The materials exhibit a lamellar organization, in which the anthraquinone units of neighboring side chains are also organized to some degree in layered structures parallel to the polythiophene main chains. The photoluminescence measurements in solution suggest that, upon photoexcitation of the polythiophene backbone, the anthraquinone moieties act as electron acceptors and the conjugated backbone as electron donor. The tunability of the donor–acceptor ratio and the morphology in the solid state make these photoactive copolymers interesting candidates for organic photoelectric conversion devices.

The synthesis and characterization of a new series of substituted polythiophenes containing an electron acceptor anthraquinone moiety in the side chain are reported. The acceptor molar content was varied by the co-polymerization of both alkylthiophene and thiophene bearing anthraquinone monomers in different ratios. NMR analysis shows a good correlation between the monomer feed composition at the beginning of the polymerization and the actual unit composition of the backbone. The conjugation length and the chemical composition of the copolymers as a function of the molecular weight have been studied by size exclusion chromatography. Small angle X-ray scattering and UV-Vis absorption spectra have been used to monitor the degree of order and chain organization in the solid state. The materials exhibit a lamellar organization, in which the anthraquinone units of neighboring side chains are also organized to some degree in layered structures parallel to the polythiophene main chains. The photoluminescence measurements in solution suggest that, upon photoexcitation of the polythiophene backbone, the anthraquinone moieties act as electron acceptors and the conjugated backbone as electron donor. The tunability of the donor–acceptor ratio and the morphology in the solid state make these photoactive copolymers interesting candidates for organic photoelectric conversion devices.

We have synthesised new conjugated donor-π-acceptor (D-π-A) chromophores 7, 9, and 12−15 in which monosubstituted tetrathiafulvalene (TTF) and trimethyl-TTF units are the donor moieties, connected by ethylenic bridges to electron-deficient benzene derivatives as the acceptor moieties. These compounds display a broad intramolecular charge transfer (ICT) band in their solution UV/Vis spectra at λmax = ca. 500 nm. The second order nonlinear optical (NLO) properties of these derivatives have been studied using the EFISH technique and calculated by semiempirical and ab initio theoretical methods. The effect of methyl substituents in the TTF moiety and the nature of the conjugated bridge are discussed. Analysis of the bond lengths obtained by an X-ray diffraction study of compound 9 reveal ICT in the solid state.

Tetrathiafulvalene (TTF) and its derivatives were originally prepared as strong electron-donor molecules for the development of electrically conducting materials. This Review emphasizes how TTF and its derivatives offer new and in some cases little-exploited possibilities at the molecular to the supramolecular levels, as well as in macromolecular aspects. TTF is a well-established molecule whose interest goes beyond the field of materials chemistry to be considered an important building block in supramolecular chemistry, crystal engineering, and in systems able to operate as machines. At the molecular level, TTF is a readily available molecule which displays a strong electron-donor ability. However, its use as a catalyst for radical–polar crossover reactions, thus mimicking samarium iodide chemistry, has only recently been addressed. Important goals have been achieved in the use of TTF at the macromolecular level where TTF-containing oligomers, polymers, and dendrimers have allowed the preparation of new materials that integrate the unique properties of TTF with the processability and stability that macromolecules display. The TTF molecule has also been successfully used in the construction of redox-active supramolecular systems. Thus, chemical sensors and redox-switchable ligands have been prepared from TTF while molecular shuttles and molecular switches have been prepared from TTF-containing rotaxanes and catenanes. A large synthetic effort has been devoted to the preparation of the so-called organic ferromagnets, many of which are derived from TTF. The main task in these systems is the introduction of ferromagnetic coupling between the conduction electrons and localized electrons. TTF has also played a prominent role in molecular electronics where TTF-containing D-σ-A molecules have allowed the preparation of the first confirmed unimolecular rectifier. Recently, it has been confirmed that TTF can display efficient nonlinear optic (NLO) responses in the second and third harmonic generation as well as a good thermal stability. These findings can be combined with the redox ability of TTF as an external stimuli to provide a promising strategy for the molecular engineering of switchable NLO materials. Fullerenes endowed with TTF exhibit outstanding photophysical properties leading to charge-separated (CS) states that show remarkable lifetimes.

Tetrathiafulvalen (TTF) und seine Derivate synthetisierte man ursprünglich als starke Elektronendonoren zur Entwicklung elektrisch leitender Materialien. In diesem Aufsatz liegt der Schwerpunkt auf neuen und teils nur wenig genutzten Anwendungsmöglichkeiten von TTF und seinen Derivaten, angefangen von der Molekülchemie bis hin zur Supramolekularen Chemie und der Makromolekularen Chemie. Das Interesse an TTF geht weit über die Materialwissenschaft hinaus, wo es als wichtiger Baustein gilt für die Supramolekulare Chemie, für das Kristall-Engineering und für Systeme, die als molekulare Maschinen fungieren können. Für die Molekülchemie ist TTF leicht zugänglich. Trotz seiner ausgeprägten Elektronendonoreigenschaften hat man aber erst kürzlich begonnen, sich mit dem Einsatz als Katalysator für mehrstufige Reaktionen mit einem Übergang von einem radikalischen zu einem polaren Mechanismus zu befassen und so die Samariumdiiodid-Chemie zu modellieren. Wichtige Ziele konnten beim Einsatz von TTF in der Makromolekularen Chemie erreicht werden. TTF enthaltende Oligomere, Polymere und Dendrimere ermöglichten die Herstellung neuer Materialien, in denen sich die einzigartigen Eigenschaften von TTF mit den Verarbeitungsmöglichkeiten und der Stabilität der Makromoleküle verbinden. Auch die Verwendung von TTF beim Aufbau redoxaktiver supramolekularer Systeme war erfolgreich. Auf diese Weise konnten aus TTF chemische Sensoren und als Redoxschalter dienende Liganden hergestellt werden, sowie aus Rotaxanen und Catenanen mit eingebauten TTF-Einheiten molekulare Shuttle und Schalter. Große Anstrengungen wurden unternommen zur Synthese so genannter organischer Ferromagnete, von denen sich viele von TTF ableiten. Die wichtigste Aufgabe bei der Herstellung solcher Systeme besteht in der Einführung einer ferromagnetischen Kopplung zwischen den Leitungselektronen und den lokalisierten Spins. TTF spielte auch eine bedeutende Rolle in der molekularen Elektronik, wo man aus D-σ-A-Molekülen mit eingebauten TTF-Einheiten nachgewiesenermaßen den ersten unimolekularen Gleichrichter herstellen konnte. Kürzlich konnte gezeigt werden, dass TTF mit einer guten thermischen Stabilität eine erste und zweite harmonische Oberschwingung als NLO-Antwort (NLO: nichtlineare Optik) erzeugen kann. Verbindet man diese Eigenschaft mit den durch ein externes Signal ansprechbaren Redoxeigenschaften von TTF, ergibt sich daraus eine viel versprechende Strategie für das molekulare Engineering schaltbarer NLO-Materialien. Fullerene, an die TTF angebunden ist, zeigen hervorragende photophysikalische Eigenschaften, und es können daraus Zustände mit Ladungstrennung von bemerkenswerten Halbwertszeiten erhalten werden.

Some of the current directions in research on new organic materials based on functionalized oligoarylenes are reviewed. Particular emphasis is placed upon the use of chemical synthesis for the incorporation of suitable functionalized oligoarylenes into more complex molecular and polymeric systems. Selected examples of applications of these materials in different fields such as light-emitting diodes, photovoltaic devices, nonlinear optics, two-photon dyes, molecular switches or ligands will be presented.

The main types of fullerene dimers synthesized so far, including the early all-carbon fullerene dimers, other new carbon allotropes containing two fullerene units and the specially interesting fullerene dimers bridged through electroactive spacers, are reviewed. The different synthetic strategies employed have been divided into two main types, namely: (i) dimerization of C₆₀ itself or some C₆₀ derivatives and (ii) bifunctional cycloaddition reactions to C₆₀.  These new systems are of interest since they can find applications in areas such as artificial photosynthesis, novel molecular electronic devices and in supramolecular chemistry.

Synthetic strategies towards appropriate symmetric and unsymmetric functionalization of the naphthalene ring are presented. By means of Knoevenagel and Wittig condensation reactions new fluorescent, differently functionalized oligo(2,6-naphthylenevinylene)s have been synthesized, the presence of terminal aldehyde or bromine substitution opening the way to the incorporation of the fluorescent trimers in a variety of polymeric materials. The effect of substituting the phenylene ring by the more bulky dialkoxynaphthalene system in arylenevinylene-type materials is studied from the structural point of view and the possibility to tune the emission color and the electron affinity through the introduction of naphthylenevinylene and cyano-substituted naphthylenevinylene units is also investigated.

The main types of cyano-containing electron acceptor molecules, particularly those derived from TCNQ and DCNQI acceptors, have been reviewed. Ring substitution, the presence of heteroatoms and extendedπ-conjugation have been used as the principal structural modifications on the acceptor framework. Recent examples of C60 based electron acceptors bearing an acceptor organic addend and other single-component donor–acceptor systems exhibiting semiconducting behaviour are also discussed.

Artificial molecular models, based on rigid dendrimeric meta-substituted phenylenevinylene moieties bearing different electron donating groups and the electron acceptor C₆₀, were probed in an effort to gain control over a sequential versus a competitive scenario in energy and electron transfer events.

In a novel series of soluble C₆₀–oligo(naphthylenevinylene) dyads both singlet–singlet energy transfer and intramolecular electron transfer were found to take place and to compete with each other.

The rational designof linear donor–acceptor arrays by integrating fully conjugated oligomers with a well‐defined length and constitution is reported by N. Martín, D. M. Guldi et al. on page 4819 ff. Photoinduced electron transfer (shown schematically in the cover picture) over distances of up to 50 Å with formation of the respective radical pairs is demonstrated. The strong electron coupling between the donor and acceptor moieties through the π‐conjugated oligomer is particularly important for the observed wire‐like behavior.