Water‐proton relaxivity of hyperbranched polymers carrying TEMPO radicals |
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| Authors: | Hiroyuki Hayashi Satoru Karasawa Akihiro Tanaka Keisuke Odoi Katsumi Chikama Hideto Kuribayashi Noboru Koga |
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| Affiliation: | 1. Graduate School of Pharmaceutical Sciences, Kyushu University, 3‐1‐1 Maidashi, Higashi‐ku, Fukuoka, 812‐8582 Japan;2. Synthesis Research Department, Chemical Research Laboratory, Nissan Chemical Industries, Ltd, 722‐1 Tuboi‐cho, Funabashi, Chiba, 274‐8507 Japan;3. Varian Technologies Japan, Ltd, 4‐16‐36 Shibaura, Minato‐ku, Tokyo, 108‐0023 Japan |
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| Abstract: | High water‐soluble hyperbranched poly(styrene) (HPS) polymers carrying stable 2, 2, 6, 6‐tetramethylpiperidine‐1‐oxyl (TEMPO) radicals, HPS‐N‐TEMPO, HPS‐Im‐TEMPO, and HPS‐Im‐(TEMPO)2, were prepared in ca. 60% introducing yield. HPS‐N‐TEMPO and HPS‐Im‐TEMPO were determined to be nearly spherical shapes of the diameter of 2.4 ± 0.6 and 2.2 ± 0.6 nm, respectively, by transmission electron microscope (TEM) images. The values of water‐proton relaxivity, r1, at 25 MHz, 0.59 T, and 25 °C were 6.0, 5.2, and 14 mM?1 sec?1 for HPS‐N‐TEMPO, HPS‐Im‐TEMPO, and HPS‐Im‐(TEMPO)2, respectively. The spin‐lattice relaxation time (T1)‐weighted images in phantom were also observed. Copyright © 2009 John Wiley & Sons, Ltd. |
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| Keywords: | NMR 1H EPR MRI Polymer TEMPO radical |
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