Tailored correlation spectroscopy

In this chapter multiple-pulse sequences for homonudear Hartmann-Hahn transfer are discussed. After a summary of broadband Hartmann-Hahn mixing sequences for total correlation spectroscopy (TOCSY), variants of these experiments that are compensated for crossrelaxation (clean TOCSY) are reviewed. Then, selective and semiselective homonudear Hartmann-Hahn sequences for tailored correlation spectroscopy (TACSY) are discussed. In contrast to TOCSY experiments, where Hartmann-Hahn transfer is allowed between all spins that are part of a coupling network, coherence transfer in TACSY experiments is restricted to selected subsets of spins. Finally, exclusive TACSY (E.TACSY) mixing sequences that not only restrict coherence transfer to a subset of spins, but also leave the polarization state of a second subset of spins untouched, are reviewed. 

Exclusive tailored correlation spectroscopy Flip-Flop spectroscopy... 

Heteronuclear multiple-quantum correlation Experiment for tailored correlation spectroscopy of H and H resonances in peptides and proteins Homonuclear Hartmann-Hahn spectroscopy Heteronuclear quadruple-quantum coherence Heteronuelear triple-quantum coherence Heteronuclear single-quantum coherence TOCSY sequences developed at the Indian Institute of Chemical Technology Insensitive nucleus enhancement by polarization transfer... 

ROESY-TOCSY experiment Selective inverse detection of C-H correlation Scalar heteronuclear recoupled interaction by multiple pulse Simulation program one Selectively inverted soft PICSY Singular value decomposition Tailored correlation spectroscopy Triple-resonance J cross-polarization Total correlation spectroscopy TOCSY-ROESY experiment TOCSY without NOESY... 

Czemey P, Lehmann F, Wenzel M, Buschmann V, Dietrich A, Mohr GJ (2001) Tailor-made dyes for fluorescence correlation spectroscopy (FCS). Biol Chem 382 495-498... 

Since the accuracy required to solve chemical problems — such as clarifying a reaction mechanism — is smaller than the accuracy that required for high-resolution spectroscopy, tailor-made methods have been devised. One example is the relativistic DKH-CASSCF/CASPT2+SO approach [1158-1160]. In view of the limited reliability of the CASSCF wave function (due to the limited size of the active space), we may well combine this ansatz with a one-component DKH Hamiltonian and sacrifice, to a certain extent, accuracy for feasibility. Dynamic correlation effects can be considered in a subsequent... 

Cross polarization can also be used for magnetization transfer between low-gamma nuclei like and as a mixing sequence in a multidimensional NMR experiment. Due to the substantial shift separation of about 120 ppm between carbonyl and Ca carbon atoms in proteins, the CP transfer can be tailored specifically to NCa- or NCO-transfer (SPECIFIC-CP) [81]. In protein NMR spectroscopy such a heteronuclear correlation experiment may be incorporated into multidimensional experiments and thus be used to residue-specific resonance assignment in NMR spectroscopy of immobilized peptides or proteins [82]. 

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