Design of NMR pulse experiments with optimum sensitivity: coherence-order-selective transfer in I2S and I3S spin systems

New pulse sequences are presented for coherence-order-selective 2 Sigma(i=1 )(n) IizS-+/- --> Sigma(i=1)(n) I-i(-) and S-/+ --> Sigma(i=1)(n) I-i(-) tr ansfer in I2S and I3S spin-1/2 systems. They are derived using a strategy f or the design of NMR pulse sequences providing the theoretical optimum tran sfer efficiency based on unitary bounds on spin dynamics, theoretical analy sis, and numerical optimization. The sensitivity of the new experimental me thods exceeds those of the best methods known so far by up to 37%. All the optimal pulse sequences combine evolution under the influence of planar and J coupling Hamiltonians. Experimental verification is performed by C-13 NM R of dichloromethane and iodomethane.