• Macromolecular Research
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• 제12권2호
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• pp.178-188
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• 2004

We performed molecular dynamics (MD) simulations at 300 K on a series of poly(benzyl ether) (PBE) dendrimers having a different core functionalities. We used the rotational isomeric state Metropolis Monte Carlo (RMMC) method to construct the initial configuration in a periodic boundary cell (PBC) before the MD simulations were undertaken. To elucidate the effects that the structural features have on the chain dimension, the overall internal structure, and the morphology, we monitored the radii of gyration, R$\sub$g/ and the conformational changes during the simulations. The PBE dendrimers in a glassy state adopted less-extended structures when compared with the conformations obtained from the RMMC calculations. We found that R$\sub$g/ of the PBE dendrimer depends on the molecular weight, M, according to the relation, R$\sub$g/∼M$\^$0.22/. The radial distributions of the dendrimers were developed identically in the PBC, irrespective of the core functionality. A gradual decrease in radial density resulted from the fact that the terminal branch ends are distributed all over the molecule, except for the core region.

• Bulletin of the Korean Chemical Society
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• 제30권1호
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• pp.157-162
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• 2009

General, fast, and efficient methods for the synthesis of Fréchet-type dendrimers having core diversities were elaborated. Two core building blocks, 4,4'-(3,5-bis(propargyloxy)benzyloxy)bisphenyl and N,N,N',N'-tetra(prop-2- ynyloxycarbonylethyl)-1,2-diaminoethane, were designed to serve as the alkyne functionalities for dendrimer growth via click reactions with the azide-dendrons. The synthetic strategy involved an 1,3-dipolar cycloaddition reaction between an alkyne and an azide- functionalized Fréchet-type dendrons in the presence of Cu(I) species which is known as the best example of click chemistry.

• Macromolecular Research
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• 제13권4호
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• pp.334-338
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• 2005

A three-layered poly(benzyl ether) dendrimer having a bis-ethynylbenzene core was synthesized and characterized with $^{1}H$ NMR and MALDI-TOF-MS spectroscopy. The dendrimer was reacted with platinum complexes to obtain platinum-acetylide based organometallic polymers. When the dendrimer was reacted with trans-[$PtCl_{2}(PEt_{3})_{2}$], a high molecular weight polymeric compound was formed, whereas, with cis-[$PtCl_{2}dppp$], a uniform molecular weight compound was formed, which was found to be a dimeric metallacycle by $^{1}H\;NMR,\;^{31}P\;NMR$ and ESI-TOF-MS spectroscopy. Both these complexes exhibited relatively a strong emission around 440 nm, indicating that they could be potential candidates for blue emitting polymer LEDs.

• 폴리머
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• 제33권1호
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• pp.67-71
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• 2009

프레체형태 덴드리머의 합성을 위한 연결 방법이 알카인기와 아지드기 사이의 클릭 화학을 이용하여 개발되었다. 덴드리머의 핵으로 작용할 수 있는 단위체인 4,4'-(3,5-비스(아지도프로필옥시)벤질옥시)비스페닐이 알카인덴드론과 클릭 반응을 통해 덴드리머의 구축을 위해 사용되었다. 즉, 구리촉매 존재하에서 다중(아지드)화합물과 말단 알킨기를 가지는 폴리(벤질에테르)덴드론 사이치 클릭 반응을 통해 덴드리머의 합성 전략이 완성되었다.