Interaction between closed-shell and open-shell molecules. 1H relaxation studies of the hydrogen bond between proton-donor molecules and a nitroxide radical

✍ Scribed by K. Endo; B. Knuettel; I. Morishima; T. Inubushi; T. Yonezawa

• Publisher: Elsevier Science
• Year: 1975
• Tongue: English
• Weight: 504 KB
• Volume: 31
• Category: Article
• ISSN: 0009-2614
• DOI: 10.1016/0009-2614(75)85046-9

✦ Synopsis

Pulsed and cw NMR methods have bezn used to investigate the 'H relkation of proton donor molecules hp drogen bonded with the DTBN radial. Frequency dependences of proton relaxation times Tr and T2 were studied with a DTBN solution of CHC.13 by the pulsed NMR method. It is shown that the relaxation mcchankm is detecmined chiefly by the nucleus-electron dipole-dipole interaction (~c 5 10 -lo s), but patially characterized by the exchange coupling. Using the rehtion (I/TI)DD = (l/T2$-,,, which holds at low magnetic fields, the lifetime of the chemical exchange associated with thz CHCl3 *..DTBN hydrogen bond was e~luated as 3.6 X 10s8 s from the difference between l/T2 and l/T1 measured at 15 blHz. 1. Iritroduction Recent& &W&ii.i~3 St 231. {I} IwfC PqQzted a