Deuterium nuclear quadrupole coupling in the hydrogen-bound systems ethylene—D35CI and acetylene—D35CI

The deuterium nuclear quadrupole coupling constants in the T-shaped π-complexes ethylene—D³⁵Cl and acetylene—D³⁵Cl have been measured to be x_aa^D = 171.1 (71) kHz for ethylene—DCl and x_aa^D = 146.3(35) kHz for acetylene—DCL. The values of x_aa^D differ from those expected from projecting the free DCl monomer values. Rotational and centrifugal distortion constants are obtained for acetylene—D³⁵Cl confirming the structure given previously for acetylene—HCl.