Heteronuclear polarization transfer in static oriented systems using a windowless multiple-pulse sequence

A new method for polarization transfer between heteronuclei for static oriented samples is presented. The method employs an INEPT like sequence for the transfer of polarization through heteronuclear dipolar couplings. A 90° pulse on the S spin sandwiched between two I spin evolution periods under BLEW-12 blocks of pulses with appropriate phases enables polarization transfer. The method has been demonstrated on a nematic liquid crystal oriented in a magnetic field. Further experiments on samples of chloroform and dichloromethane oriented in the liquid crystalline matrix demonstrate that the technique can also be used for estimating heteronuclear dipolar couplings. Calculation of scaling factors based on average Hamiltonian theory and simulations are shown to match with experiment.