Molecular Logic with a Saccharide Probe on the Few-Molecules Level

In this Communication we describe a two-component saccharide probe with logic capability. The combination of a boronic acid-appended viologen and perylene diimide was able to perform a complementary implication/not implication logic function. Fluorescence quenching and recovery with fructose was analyzed with fluorescence correlation spectroscopy on the level of a few molecules of the reporting dye

Tuning the HOMO–LUMO Gap of Pyrene Effectively via Donor–Acceptor Substitution: Positions 4,5 Versus 9,10

Donor and acceptor substituents were introduced at pyrene’s K-regions in order to engineer its optoelectronic properties. A study of the influence of the substitution pattern on the frontier orbitals as well as on the molecular packing is provided. A comparison with the pure donor and acceptor substituted pyrene derivatives highlights the strong impact of the presented donor–acceptor substitution

Synthesis of an Acceptor–Donor–Acceptor Multichromophore Consisting of Terrylene and Perylene Diimides for Multistep Energy Transfer Studies

Motivated by the results obtained from the investigation of singlet–singlet annihilation in a linear multichromophore comprising terrylene diimides (TDI) and perylene diimide (PDI) in 2010, we report the detailed process toward the successful synthesis of a TDI–PDI–TDI dyad. Ineffective synthetic pathways, which were necessary for the understanding of the step-by-step construction of the complex multichromophore, are described, leading toward a universal synthetic plan for multicomponent systems containing rylene diimides separated by rigid oligophenylene spacers

Field Effect Transistors Based on Polycyclic Aromatic Hydrocarbons for the Detection and Classification of Volatile Organic Compounds

We show that polycyclic aromatic hydrocarbon (PAH) based field effect transistor (FET) arrays can serve as excellent chemical sensors for the detection of volatile organic compounds (VOCs) under confounding humidity conditions. Using these sensors, w/o complementary pattern recognition methods, we study the ability of PAH-FET(s) to: (i) discriminate between aromatic and non-aromatic VOCs; (ii) distinguish polar and non-polar non-aromatic compounds; and to (iii) identify specific VOCs within the subgroups (i.e., aromatic compounds, polar non-aromatic compounds, non-polar non-aromatic compounds). We further study the effect of water vapor on the sensor array’s discriminative ability and derive patterns that are stable when exposed to different constant values of background humidity. Patterns based on different independent electronic features from an array of PAH-FETs may bring us one step closer to creating a unique fingerprint for individual VOCs in real-world applications in atmospheres with varying levels of humidity

B₂N₂‑Dibenzo[<i>a</i>,<i>e</i>]pentalenes: Effect of the BN Orientation Pattern on Antiaromaticity and Optoelectronic Properties

Two BN units were embedded in dibenzo­[<i>a</i>,<i>e</i>]­pentalene with different orientation patterns, which significantly modulated its antiaromaticity and optoelectronic properties. Importantly, the vital role of the BN orientation in conjugated molecules with more than one BN unit was demonstrated for the first time. This work indicates a large potential of the BN/CC isosterism for the development of new antiaromatic systems and highlights the importance of precise control of the BN substitution patterns in conjugated materials

Surface Pretreatment Boosts the Performance of Supramolecular Affinity Materials on Quartz Crystal Microbalances for Sensor Applications

A Teflon-like coating is the key for the boost in sensitivity of quartz microbalances for the tracing of airborne analytes. Since the undesired signals for the interfering compounds are suppressed and the ones for the targeted compounds (e.g., peroxide explosives) are enhanced, the PCA output is improved

Role of Sub-Nanometer Dielectric Roughness on Microstructure and Charge Carrier Transport in α<i>,</i>ω‑Dihexylsexithiophene Field-Effect Transistors

The effect of dielectric roughness on the microstructure evolution of thermally evaporated α,ω-dihexylsexithiophene (α,ω-DH6T) thin films from a single molecular layer to tens of monolayers (ML) is studied. Thereby, the surface roughness of dielectrics is controlled within a sub-nanometer range. It is found that the grain size of an α,ω-DH6T ML is affected by dielectric roughness, especially for 1.5 ML, whereby the transistor performance is barely influenced. This can be attributed to a domain interconnection in the second layer over a long-range formed on the rough surface. With deposition of more layers, both microstructure and charge carrier transport exhibit a roughness-independent behavior. The structural characterization of α,ω-DH6T 10 ML by grazing-incidence wide-angle X-ray scattering reveals that the interlayer distance is slightly decreased from 3.30 to 3.15 nm due to a higher roughness, while an unchanged π-stacking distance is in excellent agreement with the roughness-independent hole mobility. This study excludes the influence of molecular-solvent interaction and preaggregation taking place during solution deposition, and provides further evidence that the microstructure of the interfacial layer of organic semiconductors has only minor impact on the bulk charge carrier transport in thicker films

Efficient Coupling of Nanoparticles to Electrochemically Exfoliated Graphene

Electrochemically exfoliated graphene (EEG) is a new generation of high-quality graphene that holds great promise for the construction of hybrid materials. However, the assembly of EEG hybrids with well-defined nanostructures has remained a major challenge. In this study, we demonstrate a bottom-up approach toward the assembly of EEG sheets with a series of functional nanoparticles (Si, Fe₃O₄, and Pt NPs) into two-dimensional sandwich-like hybrid nanostructures. Polyaniline in the emeraldine base form functions as a versatile dopant to couple NPs onto EEG through either electrostatic interactions or hydrogen bonding. This protocol enables processing and assembly of EEG using an economical pathway, for which we further demonstrate the potential application of EEG-Si hybrids as high-performance anode material for lithium storage

Synthesis of Stable Nanographenes with OBO-Doped Zigzag Edges Based on Tandem Demethylation-Electrophilic Borylation

A tandem demethylation-aryl borylation strategy was developed to synthesize OBO-doped tetrabenzo­[<i>a,f,j,o</i>]­perylenes (namely “bistetracenes”) and tetrabenzo­[<i>bc,ef,kl,no</i>]­coronenes (namely “peritetracenes”). The OBO-doped bistetracene analogues exhibited excellent stability and strong fluorescence, in contrast to the unstable all-carbon bistetracene. Single-crystal X-ray analysis for OBO-doped bistetracene revealed a twisted double [5]­helicene structure, indicating that this synthesis is applicable to new heterohelicenes. Importantly, cyclodehydrogenation of the bistetracene analogues successfully produced the unprecedented heteroatom-doped peritetracenes, which opened up a new avenue to periacene-type nanographenes with stable zigzag edges

Positive Magneto-LC Effect in Conjugated Spin-Bearing Hexabenzocoronene

The first neutral spin carrying hexabenzocoronene (HBC) derivative is described. The conjugated phenyl nitroxide substituted HBC with five alkyl chains exhibits a positive magneto-LC effect in columnar hexagonal liquid crystalline phase as probed by differential scanning calorimetry and electron paramagnetic resonance spectroscopy. Surprisingly, at 140 K the Δ<i>M</i>_S = 2 transition can be observed indicating a thermally accessible triplet state between the neighboring molecules in the columnar arrangements