Yonggang Zhen

Revealing the Charge-Transfer Interactions in Self-Assembled Organic Cocrystals: Two-Dimensional Photonic Applications

A new crystal of a charge-transfer (CT) complex was prepared through supramolecular assembly and it has unique two-dimensional (2D) morphology. The CT nature of the ground and excited states of this new Bpe-TCNB cocrystal (BTC) were confirmed by electron spin resonance measurements, spectroscopic studies, and theoretical calculations, thus providing a comprehensive understanding of the CT interactions in organic donor-acceptor systems. And the lowest CT1 excitons are responsible for the efficient photoluminescence (Φ(PL)=19%), which can actively propagate in individual 2D BTCs without anisotropy, thus implying that the optical waveguide property of the crystal is not related to the molecular stacking structure. This unique 2D CT cocrystal exhibits potential for use in functional photonic devices in the next-generation optoelectronic communications.

One-Pot Facile Synthesis of Pyridyl Annelated Perylene Bisimides

Two regiospecifically pyridyl annelated perylene bisimides have been prepared in one pot by the combination of the Suzuki cross-coupling reaction and subsequent light-promoted cyclization in high yields.

Tuning the Crystal Polymorphs of Alkyl Thienoacene via Solution Self‐Assembly Toward Air‐Stable and High‐Performance Organic Field‐Effect Transistors

The first example for thienoacene derivatives with selective growth of different crystal polymorphs is simply achieved by solution-phase self-assembly. Compared with platelet-shaped α-phase crystals, organic field-effect transistors (OFETs) based on microribbon-shaped β-phase crystals show a hole mobility up to 18.9 cm(2) V(-1) s(-1), which is one of the highest values for p-type organic semiconductors measured under ambient conditions.

Heterocyclic annelated di(perylene bisimide): constructing bowl-shaped perylene bisimides by the combination of steric congestion and ring strain.

In this paper, we present the synthesis of S- and N-heterocyclic annelated di(perylene bisimide) with extraordinary doubly bowl-shaped structures. The structures of fused PBI bowls confirmed by single-crystal X-ray structure analysis and temperature-dependent (1)H NMR are realized by the introduction of the steric congestion in nonbay regions and by the concurrent formation of the five-membered heterorings strain in bay regions. On the basis of the geometry obtained from the X-ray analysis, the maximum POAV1 pyramidalization angle is found in N-heterocyclic annelated diPBI 7, as large as 4.7 degrees , indicating the formation of two PBI bowls with significant curvatures. Furthermore, to assist the electrochemical and spectroscopic characterization of the two bowl-shaped derivatives and to assess the influence of heteroatoms on the bowl curvature, quantum-chemically optimized atomic structures, electronic properties, and optical signatures were computed with density functional theory.

Porphyrin Supramolecular 1D Structures via Surfactant‐Assisted Self‐Assembly

One-dimensional (1D) solid-state supramolecular structures based on porphyrin chromophores arouse numerous expectations from the interdisciplinary scientific communities of supramolecular chemistry and advanced soft materials science. This stems from the intrinsic assembly capability of porphyrins to form various well-defined 1D assemblies, which have broad opportunities in the fields of advanced soft matter. A brief review on 1D porphyrin micro-/nanoassemblies constructed via surfactant-assisted self-assembly is presented here, in terms of addressing new ideas recently developed for controlled assembly, hierarchical organization, and new-type functional surfactants etc. The functionalization of the as-assembled 1D structures with regard to supramolecular photocatalysis, non-linear optics, nanoelectronic gas sensors, photoelectrochemical solar cells, etc. is highlighted.

Tetrachloro-tetra(perylene bisimides): an approach towards N-type graphene nanoribbons

An extraordinarily large pi system based on tetrachloro-tetra(perylene bisimides) with very broad absorption spectra from the UV to the NIR region and an extremely strong electron-accepting ability has been synthesized from tetrachloro-di(perylene bisimides).

One-Pot Synthesis of Well-Defined Oligo- Butadiynylene-Naphthalene Diimides

A homogeneous series of well-defined oligo-butadiynylene-NDIs containing up to five naphthalene diimides (NDIs) moieties have been efficiently synthesized in one pot by oxidative homocoupling of 1,6-di((trimethylsilyl)ethynyl)naphthalene diimides in good yields.

Solution-Processed Large-Area Nanocrystal Arrays of Metal-Organic Frameworks as Wearable, Ultrasensitive, Electronic Skin for Health Monitoring.

Pressure sensors based on solution-processed metal-organic frameworks nanowire arrays are fabricated with very low cost, flexibility, high sensitivity, and ease of integration into sensor arrays. Furthermore, the pressure sensors are suitable for monitoring and diagnosing biomedical signals such as radial artery pressure waveforms in real time.

Direct Meta-Selective Alkylation of Perylene Bisimides via Palladium-Catalyzed C−H Functionalization

A facile palladium-catalyzed procedure for meta-selective alkylation of perylene bisimides with alkyl halides has been achieved by direct C-H functionalization.

Precisely Tailoring the Stoichiometric Stacking of Perylene‐TCNQ Co‐Crystals towards Different Nano and Microstructures with Varied Optoelectronic Performances

Organic charge-transfer co-crystals with varied donor-acceptor stoichiometric ratios and molecular packing structures are controllably prepared with the morphology of nanowires or microblocks. They have distinct charge transport behavior and photoresponsivity. These interesting results pave the way for rational design and preparation of co-crystals with desired functions.