1 H‐detected studies of geminal 29 Si 13 C couplings: Dependence of coupling sign and magnitude on molecular structure

The magnitude and signs of geminal 29 SiZ 13 C coupling constants were determined for nine derivatives of representative organosilicon compounds [Z = C(sp 2 , sp 3 ), N, O, (two‐ and three‐coordinate), Si, S] from 1 H‐detected two‐dimensional (2D) Ψ‐BIRD‐HSQC and Ψ‐BIRD‐HMQC pseudo‐triple resonance 1 H 29 Si( 13 C) and 1 H 13 C( 29 Si) experiments. The high sensitivity of the method allowed the measurements to be carried out in less than 1 h using 2–10 mg of the respective compound. Couplings as small as 0.45 Hz have been resolved. The couplings ranged from −21.4 to +2.2 Hz, showing regular dependence on the nature, hybridization and coordination of the intervening Z atom.