Concatenated cross-polarization

If the coupling constants are known in advance, the total mixing time can be reduced in multiple-step selective coherence-transfer experiments by using the selective homonuclear analog of the optimized heteronuclear two-step Hartmann-Hahn transfer technique proposed by Majumdar and Zuiderweg (1995). In this technique [concatenated cross-polarization (CCP)] a doubly selective transfer step (DCP) is concatenated with a triple selective mking step (TCP). For the case of a linear three-spin system with effective planar coupling tensors, a CCP experiment yields complete polarization transfer between the first and the third spin and the total transfer... 

Zuiderweg, 1995). In the case of a linear ISQ system, concatenated cross-polarization (CCP Majumdar and Zuiderweg, 1995) is more efficient than two sequential double-resonance (DCP) Hartmann-Hahn transfer steps. The CCP scheme is a combination of a DCP and TCP experiment with optimized mixing times Tj and Tj that depend on the magnitudes of and J Q (Majumdar and Zuiderweg, 1995). 

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