✦ LIBER ✦
Variable-effective-field cross polarization. An approach to broadband Hartmann-Hahn matching in MAS NMR
✍ Scribed by Andrew C. Kolbert; Sheryl L. Gann
- Publisher
- Elsevier Science
- Year
- 1994
- Tongue
- English
- Weight
- 516 KB
- Volume
- 224
- Category
- Article
- ISSN
- 0009-2614
No coin nor oath required. For personal study only.
✦ Synopsis
A method for broadening the Hartmann-Hahn matching condition for cross polarization under magic angle spinning is presented. Variabkfkctive-field cross polarization (VEFCP) employs different effective radio-frequency (rf ) fields on the 'H channel during mixing, while the "C rffield remains constant. VEFCP is shown to result in both a broader matching condition, and a more rapid polarization transfer than ordinary cross polarization at the Hartmann-Hahn match. Experimental results on both adamantane and polycarbonate are discussed.