Hongyu Zhang

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Peptide amphiphiles readily self-assemble into a variety of nanostructures, but how molecular architectures affect the size and shape of the nanoaggregates formed is not well understood. From a combined TEM and AFM study of a series of cationic peptide surfactants AmK (m = 3, 6, and 9), we show that structural transitions (sheets, fibers/ worm-like(More)
Graphdiyne, consisting of sp- and sp(2)-hybridized carbon atoms, is a new member of carbon allotropes which has a natural band gap ~1.0 eV. Here, we report our first-principles calculations on the stable configurations and electronic structures of graphdiyne doped with boron-nitrogen (BN) units. We show that BN unit prefers to replace the sp-hybridized(More)
The synthesis and spectroscopic characterization of a series of luminescent platinum meso-tetrakis{3,5-di[(N-carbazyl)n-alkyloxyphenyl]}porphyrin (Pt-8Cn-TPP, n-alkyl = (CH2)n, n = 4, 6, and 8) are presented. The protonated platinum porphyrins ([Pt-8Cn-TPPH8]8+) were assembled with mesoporous silica MCM-48 resulting in the assembly materials(More)
Herein, we describe the molecular electronic structure, optical, and charge-transport properties of anthracene derivatives computationally using density functional theory to understand the factors responsible for the improved efficiency and stability of organic light-emitting diodes (OLEDs) with triphenylamine (TPA)-substituted anthracene derivatives. The(More)
A series of highly efficient deep red to near-infrared (NIR) emissive organic crystals 1-3 based on the structurally simple 2'-hydroxychalcone derivatives were synthesized through a simple one-step condensation reaction. Crystal 1 displays the highest quantum yield (Φf) of 0.32 among the reported organic single crystals with an emission maximum (λem) over(More)
Strong supramolecular interactions, which induced tight packing and rigid molecules in crystals of cyano substituent oligo(para-phenylene vinylene) (CN-DPDSB), are the key factor for the high luminescence efficiency of its crystals; opposite to its isolated molecules in solution which have very low luminescence efficiency.
The structural, electronic, and carrier transport properties of bathocuproine (BCP), which is a typical hole/exciton-blocking material applied in organic light-emitting diodes (OLEDs), have been investigated based on density functional theory (DFT) and ab initio HF method. The detail characterizations of frontier electronic structure and lowest-energy(More)
The structural and electronic properties of two heteroleptic iridium complexes Ir(dfppy)2(pic) (FIrpic) and Ir(dfppy)2(acac) (FIracac) have been investigated theoretically, where dfppy = 2-(2,4-difluorophenyl) pyridine, pic = picolinic acid, and acac = acetoylacetonate. The geometries of ground and excited states are optimized at PBE0/LANL2DZ and(More)
To reveal the nature of the zinc(II)-ion-induced ionochromic effect of bipyridine (bpy)-containing pi-conjugated polymers, we proposed an electrostatic interaction mechanism to illustrate our recent experimental findings [Tian, L., et al. J. Phys. Chem. B 2005 109 (15), 6944]. Our theoretical analysis was based on the semiempirical (INDO/2) calculation of(More)
The microporous coordination polymer [Co(H2 L)(bipy)0.5 ]⋅2 H2 O (1, bipy=4,4'-bipyridine) was synthesized on the basis of the V-shaped flexible diphosphonate ligand (2,4,6-trimethyl-1,3-phenylene)bis(methylene)diphosphonic acid (H4 L) and the auxiliary bipy ligand under hydrothermal conditions. The structure of this compound was characterized by(More)