Longer-range distances by spinning-angle-encoding solid-state NMR spectroscopyElectronic supplementary information (ESI) available: Further details: angle switching; angle calibration; the double Gaussian selective pulses. See DOI: 10.1039/c0cp02364g

• Main Authors: Becker-Baldus, Johanna, Kemp, Thomas F, Past, Jaan, Reinhold, Andres, Samoson, Ago, Brown, Steven P
• Format: Journal Article
• Language: English
• Published: 23.02.2011
• ISSN: 1463-9076; 1463-9084
• DOI: 10.1039/c0cp02364g

A new spinning-angle-encoding spin-echo solid-state NMR approach is used to accurately determine the dipolar coupling corresponding to a C-C distance over 4 Å in a fully labelled dipeptide. The dipolar coupling dependent spin-echo modulation was recorded off magic angle, switching back to the magic angle for the acquisition of the free-induction decay, so as to obtain optimum sensitivity. The retention of both ideal resolution and long-range distance sensitivity was achieved by redesigning a 600 MHz HX MAS NMRprobe to provide fast angle switching during the NMR experiment: for 1.8 mm rotors, angle changes of up to ∼5° in ∼10 ms were achieved at 12 kHz MAS. A new experimental design that combines a reference and a dipolar-modulated experiment and a master-curve approach to data interpretation is presented. A new spinning-angle-encoding spin-echo solid-state NMR approach incorporating a reference and a dipolar-modulated experiment allows the accurate determination of the dipolar coupling corresponding to a C-C distance over 4 Å in a fully labeled dipeptide.