BaBa-xy16: Robust and broadband homonuclear DQ recoupling for applications in rigid and soft solids up to the highest MAS frequencies

Topological behavior mimicking ethylene–hexene copolymers using branched lactones and macrolactones

“…S5, S9-S11 †). To further characterize the inuence of cyclic PPDL on PeDL-block-PPDL we have recorded 1 H-1 H double quantumsingle quantum (DQ-SQ) correlation spectra and relaxationnormalized 1 H-1 H DQ build-up curves 20 to study the polymer chain dynamics before and aer preparative GPC purication (Fig. S12 †) 21 For as-synthesized PeDL-block-PPDL, the DQ build-up curves show a slight spread with a noticeable decay for sites 14 and 26.…”

Measurement of homonuclear magnetic dipole–dipole interactions in multiple 1/2-spin systems using constant-time DQ-DRENAR NMR

“…In the following we will discuss the performance of CT-DRENAR in both of the most two powerful DQ-excitation variants, namely the POST-C7 sequence introduced by Hohwy and Jacobsen [23] and the BABA-xy16 method recently introduced by Saalwächter [32]. To this end we will present simulations as well as experimental results on a number of crystalline phosphorus-and siliconcontaining model compounds.…”

“…It is well known that advanced back-to-back (BABA) 90°pulse schemes can produce pure double quantum Hamiltonians [32][33][34].…”

“…As a result, among the numerous homonuclear dipolar recoupling methods that have been developed , no clear method of choice can be identified. A powerful approach of homonuclear re-coupling is based on the excitation of double quantum coherences using suitable excitation strategies [20][21][22][23][24][25][26][27][28][29][30][31][32][33][34]. In many of these studies internuclear distances in two-spin systems and average dipolar coupling constants in many-spin systems have been determined by measuring DQ coherence intensities as a function of excitation time.…”

Constant-time 2D and 3D through-bond correlation NMR spectroscopy of solids under 60 kHz MAS

“…7,8 Therefore, a combination of through-bond and through-space correlation experiments could be used to determine molecular structures and inter-molecular assemblies. Inspite of the development of a diverse set of dipolar-coupling driven experiments and their application to determine heteronuclear/homonuclear connectivity and distances, [9][10][11][12][13][14][15][16][17][18][19][20][21][22][23] relatively few experiments [24][25][26][27][28][29][30][31][32] make use of scalar coupling for structural studies due to its smaller magnitude, when compared to dipolar coupling, in solids. For example, the dipolar coupling between single bonded 13 C− 13 C pair is around 2 kHz, whereas the scalar coupling is only around 55 Hz.…”