Avoiding Steric Congestion in Dendrimer Growth through Proportionate Branching. A Twist on da Vinci's Rule of Tree Branching

Journal Article · Fri Oct 05 00:00:00 EDT 2012 · Journal of Organic Chemistry

DOI:https://doi.org/10.1021/jo301718y· OSTI ID:1062415

Yue, Xuyi ^[1]; Taraban, Marc B. ^[1]; Hyland, Laura L. ^[1]; Yu, Yihua Bruce ^[1]

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1. Univ. of Maryland, Baltimore, MD (United States)

In making defect-free macromolecules, the challenge occurs during chemical synthesis. This challenge is especially pronounced in dendrimer synthesis where exponential growth quickly leads to steric congestion. To overcome this difficulty, proportionate branching in dendrimer growth is proposed. In proportionate branching, both the number and the length of branches increase exponentially but in opposite directions to mimic tree growth. The effectiveness of this strategy is demonstrated through the synthesis of a fluorocarbon dendron containing 243 chemically identical fluorine atoms with a MW of 9082 Da. Monodispersity is confirmed by nuclear magnetic resonance spectroscopy, mass spectrometry, and small-angle X-ray scattering. Moreover, growing different parts proportionately, as nature does, could be a general strategy to achieve defect-free synthesis of macromolecules.

• Research Organization: Argonne National Lab. (ANL), Argonne, IL (United States). Advanced Photon Source (APS)
• Sponsoring Organization: USDOE Office of Science (SC), Biological and Environmental Research (BER)
• DOE Contract Number: FG02-08CH11527; AC02- 06CH11357
• OSTI ID: 1062415
• Journal Information: Journal of Organic Chemistry, Vol. 77, Issue (20) ; 10, 2012; ISSN 0022-3263
• Country of Publication: United States
• Language: ENGLISH