A Theoretical Investigation of 2D MAXY-JRES NMR Spectroscopy of CD_nCD_m Groups

Abstract

There exists a variety of multiple-pulse NMR experiments for spectral editing of complex molecules in solution. Maximum quantum correlation NMR (MAXY NMR) spectroscopy is one of the techniques for distinguishing CHn groups by editing 1H NMR spectra. Spectral assignments of 2D homonuclear J-resolved NMR spectroscopy become too difficult, due to complex overlapping spectra. In order to overcome this problem a new technique called 2D MAXY-JRES NMR spectroscopy, which is the combination of MAXY NMR and homonuclear J-resolved NMR spectroscopy, is used. In this study, product operator description of 2D MAXY-JRES NMR spectroscopy is performed for ISnI’S’ m (I = I’ = ½ ; S = S’ = 1; n = 1,2, 3; m = 1, 2) multi-spin systems. Experimental suggestions are made and simulated spectra are presented for the 2D MAXY-JRES NMR experiment. Therefore, it is shown that 2D MAXY-JRES NMR spectroscopy can be used to distinguish CD, CD2 and CD3 groups from each other in CDnCDm groups.

Multiplicity editing by 2D E-HSQC NMR spectroscopy: a product operator theory study

“…where H J = 2π JI z S z is the weak coupling Hamiltonian, c n J = cos(nπ J t) and s n J = sin(nπ J t). A complete product operator theory for the weakly coupled I S (I = 1/2, S = 1/2, 1) spin system has been presented in our previous works [24,25]. All evolutions under the rf pulse, spin-spin coupling and chemical shift Hamiltonians can be found in that study.…”

“…This expression is known as the Baker-Campbell-Hausdorff formula [21]. Evolutions of the product operators under the rf pulse, chemical shift and spin−spin coupling Hamiltonians can be easily obtained by using this formula [17,[21][22][23][24][25][26]. The effects of the x-axis rf pulse on some of the Cartesian spin angular momentum operators for S = 1/2 or 1 are given in the following equations:…”

“…It is well known that the product operator theory as a quantum mechanical method is widely used for analytical description of multipulse NMR experiments having mostly two spin-1/2 systems or a spin-1/2 and a spin-1 system in liquids [16][17][18][19][20][21][22][23][24][25][26]. This method not only allows the confirmation of experimental results but also offers to make some experimental suggestions on NMR experiments.…”

“…This method not only allows the confirmation of experimental results but also offers to make some experimental suggestions on NMR experiments. In our previous studies, a complete product operator theory for a weakly coupled I S (I = 1/2, S = 1) spin system has been presented and analytical descriptions of some NMR experiments including editing pulses have been presented by using the product operator formalism for the CD n groups [24][25][26]. In these studies, theoretical predictions and experimental suggestions have been made for subspectral editing of CD, CD 2 and CD 3 groups.…”

Product operator descriptions of the 2D DEPT J-resolved NMR experiment for weakly coupled ISn (, ; n=1, 2, 3) spin systems

“…In order to analyze and describe the multi-pulse NMR experiments, an effective and useful tool is the product operator theory, which is a simple quantum mechanical method [11,12]. This method has been used for weakly coupled two-spin- 1 2 systems or a spin-1 system in liquids [9,11,[12][13][14][15][16][17][18][19][20][21]. Likewise, the product operator theory of the 2D DEPT J -resolved NMR experiment for weakly coupled I S n (I = 1 2 , S = 1; n = 1, 2, 3) spin systems has been reported [22].…”