Effectively doubling the magnetic field in spin-1/2-spin-1, HSQC, HDQC, coupled HSQC, and coupled HDQC in solution NMR.
Pulse sequences for spin-1/2-spin-1 pair heteronuclear single quantum correlation (HSQC), heteronuclear double quantum correlation (HDQC), and coupled-HSQC, and coupled-HDQC NMR spectroscopies are outlined, and experimental realization for a (13)C-(2)H pair is demonstrated in solution state. In both the coupled versions, conditions for generation of in-phase and antiphase multiplets in either dimension are arrived at. The patterns and the intensity ratios are explained. The double quantum (2Q) experiments confirm doubling of both the shift frequency and the splitting due to coupling (to spin 1/2) of the 2Q coherence emanating from spin 1. The frequency doubling is equivalent to the corresponding single quantum (1Q) coherence at double the magnetic field strength. The coupling doubling, however, is independent of the magnetic field strength and a signature feature of the 2Q coherence. The ramification of the relative relaxation rates of 1Q and 2Q coherences is discussed.
Shekar
S Chandra
SC
Department of Molecular Pharmacology, Albert Einstein College of Medicine, Yeshiva University, 1300 Morris Park Avenue, Bronx, NY 10461, USA. scshekar@medusa.bioc.aecom.yu.edu
Backer
Jonathan M
JM
Girvin
Mark E
ME
D001554:Benzene / Q000737:chemistry; D002247:Carbon Isotopes / Q000737:chemistry; D004146:Dioxanes / Q000737:chemistry; D004574:Electromagnetic Fields; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D008968:Molecular Conformation; D011789:Quantum Theory; D012399:Rotation; D012996:Solutions / Q000737:chemistry*; D013113:Spin Labels; D013997:Time Factors
D002247:Carbon Isotopes; D004146:Dioxanes; D012996:Solutions; D013113:Spin Labels; D001554:Benzene; C025223:1,4-dioxane