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Dendron Generation (dendron + generation)

Distribution by Scientific Domains

Polymers and Materials Science	80%

Distribution within Polymers and Materials Science

General & Introductory Materials Science	50%

Selected Abstracts

Solution-Processible Red Iridium Dendrimers based on Oligocarbazole Host Dendrons: Synthesis, Properties, and their Applications in Organic Light-Emitting Diodes,

ADVANCED FUNCTIONAL MATERIALS, Issue 18 2008
Junqiao Ding
Abstract A series of novel red-emitting iridium dendrimers functionalized with oligocarbazole host dendrons up to the third generation (red-G3) have been synthesized by a convergent method, and their photophysical, electrochemical, and electroluminescent properties have been investigated. In addition to controlling the intermolecular interactions, oligocarbazole-based dendrons could also participate in the electrochemical and charge-transporting process. As a result, highly efficient electrophosphorescent devices can be fabricated by spin-coating from chlorobenzene solution in different device configurations. The maximum external quantum efficiency (EQE) based on the non-doped device configuration increases monotonically with increasing dendron generation. An EQE as high as 6.3% was obtained as for the third generation dendrimer red-G3, which is about 30 times higher than that of the prototype red-G0. Further optimization of the device configuration gave an EQE of 11.8% (13.0,cd A,1, 7.2,lm W,1) at 100,cd m,2 with CIE coordinates of (0.65, 0.35). The state-of-the-art performance indicated the potential of these oligocarbazole-based red iridium dendrimers as solution processible emissive materials for organic light-emitting diode applications. [source]

Solution-Processable Carbazole-Based Conjugated Dendritic Hosts for Power-Efficient Blue-Electrophosphorescent Devices

ADVANCED MATERIALS, Issue 48 2009
Junqiao Ding
A novel class of hosts suitable for solution processing has been developed based on a conjugated dendritic scaffold. By increasing the dendron generation, the highest occupied molecular orbital (HOMO) energy level can be tuned to facilitate hole injection, while the triplet energy remains at a high level, sufficient to host high-energy-triplet emitters. A power-efficient blue-electrophosphorescent device based on H2 (see figure) is presented. [source]

Synthesis and self-organization of rod,dendron and dendron,rod,dendron molecules

JOURNAL OF POLYMER SCIENCE (IN TWO SECTIONS), Issue 22 2003
Sébastien Lecommandoux
Abstract We synthesized molecules containing one or two dendritic segments and a rigid-rod-like segment with their structures in the solid state. The molecules with rod,dendron or dendron,rod,dendron architecture had biphenyl ester rigid segments and 3,4,5 tris(n -dodecyloxy)benzoate of first or second generation as their dendritic segments. The variables investigated included the rod segment length as well as dendron generation, and all materials obtained were characterized by optical microscopy, differential scanning calorimetry, and X-ray scattering. Depending on the size of the rod segment and generation number of the dendritic segment, molecules organized into smectic, columnar, or cubic phases, and the symmetries observed were dominated by the anisotropic rod,rod interactions. © 2003 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 41: 3501,3518, 2003 [source]

Multi-Colour Electroluminescence of Dendronic Antennae Containing Pyrenes as Light Harvesters

CHEMPHYSCHEM, Issue 3 2010
Umberto Giovanella Dr.
Abstract Dendronic antennae systems containing pyrene units as energy donors and a styrylpyridinium derivative as energy acceptor show efficient energy transfer from the green-emitting pyrene excimer to the red-emitting acceptor. For the third dendron generation the effective screening of the pyrene units on the acceptor provides thin films showing bright red emission. Single-layer light-emitting diodes prepared by properly balancing the dendrons and donor units concentration in polyvinylcarbazole show electroluminescence from the blue, green and red components of the monomeric donor, the donor excimer and the acceptor when excitons are generated in the polymer and subsequently transferred to the molecules by resonant energy transfer. [source]

Synthesis and properties of dendritic polymers based on natural amino acids

MACROMOLECULAR SYMPOSIA, Issue 1 2003
Alexander Bilibin
Abstract Different approaches, including polycondensation, polymerization, polymer analog condensation, and ionic binding have been investigated for synthesis of amino acid-based dendritic polymers. It was shown that a growth of dendrons generation prevents obtaining of products with high polymerization degree in polycondensation and polymerization procedures. In polymer analog condensation a growth of dendrons generation leads to considerable decrease of polymer analog reaction rate as well as substitution degree. Degree of ionic binding depends on a strength of ionogenic groups and dendrns generation. [source]