Quantitative analysis of¹⁴N quadrupolar coupling using¹H detected¹⁴N solid-state NMR

Abstract

Quantitative analysis of the 14N quadrupolar interactions using proton detected 14N magic-angle spinning NMR and high-performance numerical simulations.

A dimeric chlorophyll electron acceptor differentiates type I from type II photosynthetic reaction centers

“…Article also be possible to resolve these nitrogens by using PS I isotopically labeled with 15 N, as was done with the primary donor in Rhodobacter sphaeroides (Lendzian et al, 1992(Lendzian et al, , 1993. This would be a useful experiment to perform with the understanding, however, that such experiments would come at the loss of information on the quadrupolar coupling (Jarvis et al, 2019). The quantitative prediction of magnetic parameters using DFT methods that are described in this section neglect long-range interactions, such as those of the nearby Chl of the primary donor, P 700 , which may influence the magnitude of the coupling constants.…”

Optimisation of 1H PMLG homonuclear decoupling at 60 kHz MAS to enable 15N–1H through-bond heteronuclear correlation solid-state NMR spectroscopy

“…[9][10][11][12][13][14] In particular, 1 H detection is advantageous for the identification of specific correlations to nuclei with low gyromagnetic ratio, , such as the two naturalabundant isotopes of nitrogen, 14 N and 15 N. Our focus here is on the spin I = 1/2 15 N, though it is to be noted that there is increasing application of 14 N-1 H experiments for the much higher natural abundance (99.6%) spin I = 1 nucleus. [15][16][17][18][19][20][21][22] The low sensitivity of 15 N, associated with its low natural abundance and gyromagnetic ratio, can be overcome by the use of 15 N-1 H correlation experiments with proton acquisition, thanks to the high natural abundance and  that characterise protons, provided that fast MAS can achieve sufficient 1 H line narrowing. [23][24][25][26] We note that an 15 N-detected MAS-J-HMQC 1 H- 15 N two-dimensional spectrum has also been recorded at natural abundance and 12.5 kHz MAS using Frequency Switched Lee-Goldburg (FSLG) 1 H homonuclear decoupling.…”

Detection of remote proton–nitrogen correlations by 1H-detected 14N overtone solid-state NMR at fast MAS

“…Other methods have also been developed, such as double crosspolarization (DCP) 23 and TRAPDOR-HMQC (or T-HMQC). [24][25][26] D-HMQC, DCP, and T-HMQC experiments have found applications on many biological, chemical, and pharmaceutical solids. [27][28][29][30][31][32][33][34][35][36] The detection of the one-bond 1 H- 14 N correlation by the three experiments above is simple and highly efficient.…”