Inverse gated decoupling method

Spin-lattice relaxation times (Ti) for the a-carbon region were determined by the inversion-recovery technique [19]. Nuclear Overhauser Enhancements (NOE) were measured by the gated decoupler method [20]. 

All other sPP and the catalyst samples were recorded with a Varian VXR-5000 spectrometer. The polymers were 5-10% (w/w) solutions in TCB with dg-benzene added as a lock solvent. C-13 NHR spectra were obtained at 75.43 HHz and 120 C using SCpulse width and a 15 second delay time. Inverse gated decoupling with Waltz modulation was used to suppress NOE s for purposes of quantitation. The LAB ONE curve fitting program from New Methods Research Inc. (NHRi) in New York was used to quantify the SPP rr centered methyl pentads and hexads in the SPP spectra. 

Spin-lattice relaxation times were measured by the fast inversion-recovery method (24) with subsequent data analysis by a non-linear three parameter least squares fitting routine. (25) Nuclear Overhauser enhancement factors were measured using a gated decoupling technique with the period between the end of the data acquisition and the next 90° pulse equal to eibout four times the value. Most of the data used a delay of eibout ten times the Ti value. (26)... 

All C spectra were recorded at 50.3 Mz using a Varlan XL-200 spectrometer at ambient temperature. Gated decoupling was employed to remove all NOE. Polymers were dissolved in D 0 at 5-10% concentration. Dloxane was used as an internal standard. Tl s were determined by the inversion recovery method. 

---