SELECTIVE MAGNETIC-RESONANCE CORRELATION SPECTROSCOPY WITH IN-PHASE MULTIPLETS

New two-dimensional nuclear magnetic resonance (NMR) correlation metho ds are presented which allow one to obtain selected high-resolution mu ltiplets where all signals have positive pure absorption peak shapes. The multiplets do not suffer from any cancellation effects, and their fine structure consists of a simple superposition of square patterns i n two-dimensional frequency domain that can be readily interpreted. Th e intensities of multiplets obey the same simple binomial rules as tho se in conventional one-dimensional NMR spectra. The methods rely on a transfer of in-phase magnetization during a doubly selective irradiati on period. Complications arising from undesirable coherence-transfer p henomena are eliminated either by removing antiphase terms while leavi ng the in-phase components unaffected or by a combination of spin-lock ing of in-phase terms and elimination of antiphase terms.