Gas phase structure of tetramethylethylene

Abstract

The gas phase structure of 2,3-dimethylbut-2-ene was investigated by electron diffraction. The data extended from q= 8 to 130 Å^–1. The following converged r_g values were obtained by the least squares fitting of the calculated to experimental molecular intensity curve: r(CC)= 1.351 ± 0.003 Å, r(C—C)= 1.516 ± 0.002 Å, r(C—H)= 1.111 ± 0.003 Å, ∠ CC—C = 123.4 ± 0.2°, ∠ CCH = 111.1 ± 0.8° and τ(H—C—C—C)= 38.1 ± 5.3°. The diffraction data are compatible with a coplanar carbon skeleton. The analysis was performed with programs recently developed for an augmented DEC PDP-9 computer.