Molecular g-tensor, molecular magnetic susceptibility anisotropy, and molecular electric quadrupole moment tensor of allene from a rotational Zeeman effect study of 1,1-dideuteroallene

Abstract The high-field rotational Zeeman effect has been observed in H 2 CCCD 2 by microwave Fourier transform spectroscopy to give the molecular g -values g aa = −0.30055(54) and g bb = −0.01248(2) and the molecular magnetic susceptibility anisotropy (ξ ∥ - ξ ⊥ ) = 0.39(36) 10 −6 erg G −2 mole −1 for H 2 CCCD 2 . Arguments are given, which show conclusively that the g -values are negative. From these data the molecular electric quadrupole moment of the parent species, H 2 CCCH 2 , follows as Q aa = 3.29(41) D A . The experimental results are compared to an ab initio calculation carried out at the experimental r e -structure.