SIMULTANEOUS DETERMINATION OF THE LI-6 NUCLEAR QUADRUPOLAR COUPLING-CONSTANT AND CHEMICAL-SHIFT ANISOTROPY IN MONOMERIC TRI(ISOPROPYL)PHENYLLITHIUM

Line shape analysis of the natural abundance Li-6 cross polarization N MR powder spectrum of 2,4,6-tri(isopropyl)phenyllithium yields a Li-6 quadrupolar coupling constant, chi, of (+/-)6.63 +/- 0.10 kHz and a Li chemical shift anisotropy, Delta delta, of +24 +/- 4 ppm. The Li-6 an d Li-7 spectra and the C-13 CP/MAS spectrum indicate that solid 2,4,6- tri(isopropyl)phenyllithium exists as a monomer, in contrast to the re ported dimeric structure of the solid etherate. Ab initio molecular or bital calculations (MP2/6-31G*) for phenyllithium yield a chi(Li-6) v alue of 7.38 kHz.