A Product Operator Theory of DEPTQ NMR Spectroscopy for $IS_{n}$ (I = 1/2; S = 1; n = 0, 1, 2, 3) Spin Systems

Distortionless enhancement by polarization transfer including the detection of quaternary nuclei is a carbon-editing pulse NMR experiment. In this experiment multiplicity information for all carbons including quaternary carbons are obtained. In the present study, analytical descriptions of DEPTQ NMR experiment have been investigated for weakly coupled $IS_{n}$ (I = 1/2; S = 1; n = 0, 1, 2, 3) spin systems by using the product operator theory. Then, the theoretical discussion and the experimental suggestions for sub-spectral editing of C, CD, $CD_2$ and $CD_3$ groups have been presented. The comparison of the obtained results with those of the basic distortionless enhancement by polarization transfer NMR experiment has been also performed for $CD_{n}$ groups. It is shown that DEPTQ experiment can be also used for $CD_{n}$ groups.