Figure 2.

NMR spectral assignments of htel27[Br22] in Na⁺ solution. (A) Guanine imino protons were assigned based on¹⁵N-filtered spectra of samples, 2% ¹⁵N-labeled at the indicated positions. The reference spectrum (ref.) with the respective guanine imino proton assignments is shown at the top. (B) Examples of adenine and guanine H8 proton assignments through site-specific ²H labeling at the indicated positions. (C) Through-bond correlations between guanine imino and H8 protons via ¹³C5 at natural abundance, using long-range J-couplings shown in the inset. Missing/weak correlations are framed in boxes.