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.
All Science Journal Classification (ASJC) codes
- 化学 (全般)