ABSTRACT Spin-lattice relaxation times, T1s, for 13C nuclei in two cations H n1n+ (n = 1, 5) of N-(2-aminoethyl)-cyclam (1, scorpiand) were determined by means of 13C{1H} NMR experiments in aqueous solution at pH 11.5 and 0.2. The theoretical study [modeling with OPLS-AA, B3LYP/6-31G(d) geometry optimizations, dispersion-corrected energies (DFT-D3), and DFT-GIAO predictions of the NMR chemical ...

Methyl groups provide an important source of structural and dynamic information in NMR studies of proteins and their complexes. For this purpose sequence-specific assignments of methyl 1H and 13C resonances are required. In this paper we propose the use of 13C-detected 3D HN(CA)C and HMCMC experiments for assignment of methyl 1H and 13C resonances using a single selectively methyl protonated, p...

The relative chemical shifts and 2J(PC) coupling constants in the low-temperature limiting spectra of a series of Ph(R,N)PCl compounds [R = Me, Et, PhCH2, ‘Pr and c-Hex] differ for R = primary or secondary. For primary alkyl substituents, the more downfield signal exhibits a large, positive coupling and the more upfield resonance shows a small, negative coupling. These observations are reversed...

Paramagnetic metal ions can induce molecular alignment with respect to the magnetic field. This alignment generates residual anisotropic chemical shifts (RACS) due to nonisotropic averaging over the molecular orientations. Using a 30 kDa protein-protein complex, the RACS effects are shown to be significant for heteronuclear spins with large chemical shift anisotropies, lanthanide ions with larg...