Scheme for 2D pulse sequences and experiments Preparation Evolution Mixing Acquisition t The first perturbation of the system(pulse)was called the preparation of the spin system The variable te is called the evolution time, tr We have a mixing event, in which information from one part of the spin system is relayed to other parts. Finally, we have an acquisition period (t2)as with all ID experiments THMMR
Scheme for 2D pulse sequences and experiments Preparation Evolution Acquisition t1 t2 Mixing THNMR YAN • The first perturbation of the system (pulse) was called the preparation of the spin system. • The variable tE is called the evolution time, t1 . • We have a mixing event, in which information from one part of the spin system is relayed to other parts. • Finally, we have an acquisition period (t2 ) as with all 1D experiments
What is 2D NMR? Preparation Evolution Magnetization Detection t2 FT(2) FT(11) S(142) 2 以异核13C-相关实验为例来说明2DNM实验的四个时期: 准备期( Preparation)、发展期( Evolution) 混合期( Magnetization transfer)和探测期( detection)
以异核13C－1H相关实验为例来说明2D NMR实验的四个时期： 准备期(Preparation)、发展期(Evolution)、 混合期(Magnetization transfer)和探测期(detection)。 What is 2D NMR? THNMR YAN
What is 2D NMR? √ 2D IR Yan YB, Luo XC, Zhou HM, Zhang RQ Chinese sci bull. 2002. 47: 389-393 THMMR Fabian H, Mantsch HH, Schultz CP. PNAS. 1999, 96: 13153-1315
THNMR YAN What is 2D NMR? Fabian H, Mantsch HH, Schultz CP. PNAS. 1999, 96: 13153–1315 Yan YB, Luo XC, Zhou HM, Zhang RQ. Chinese Sci Bull. 2002, 47: 389-393 2D IR
Typical pulse sequences used in(a) NMr spectroscopy and(b) heterodyned 2D-IR spectroscopy. t2 t3 The three pulses in both techniques are Pulse FID separated by time delays t1 and t 2, and the FID is measured versus t3 In heterodyned 几几几 2D-IR. the three ir laser beams and the emitted FID signal beam all travel in different directions, and thus are spatially separated from one another the electric field of the signal beam cannot be measured directly, as it is in NMR, so it is overlapped with a fourth local-oscillator beam that heterodynes the Current Opinion in Structural Biolog signal (not shown). When t2=0, the 2D-IR spectrum is analogous to a CosY experiment otherwise it is similar to noesy THMMR anni MT and Hochstrasser RM. Current Opinion in Structural Biology 2001, 11: 516-522
THNMR YAN The three pulses in both techniques are separated by time delays t1 and t2, and the FID is measured versus t3. In heterodyned 2D-IR, the three IR laser beams and the emitted FID signal beam all travel in different directions, and thus are spatially separated from one another. The electric field of the signal beam cannot be measured directly, as it is in NMR, so it is overlapped with a fourth local-oscillator beam that heterodynes the signal (not shown). When t2 = 0, the 2D-IR spectrum is analogous to a COSY experiment, otherwise it is similar to NOESY. Zanni MT and Hochstrasser RM. Current Opinion in Structural Biology 2001, 11:516–522 Typical pulse sequences used in (a) NMR spectroscopy and (b) heterodyned 2D-IR spectroscopy
Scheme for a 2D MR spectrum Diagonal signals. results from contributions of the magnetization that has not been lo, changed by the mixing sequence A (equal frequency in both dimensions) Cross signals originate from nuclei that exchanged magnetization during the mixing time (frequencies of the first and second nucleus in each dimension B respectively). They indicate an interaction of these two nuclei THMMR
Scheme for a 2D NMR spectrum THNMR YAN Diagonal signals: results from contributions of the magnetization that has not been changed by the mixing sequence (equal frequency in both dimensions). Cross signals: originate from nuclei that exchanged magnetization during the mixing time (frequencies of the first and second nucleus in each dimension, respectively). They indicate an interaction of these two nuclei