Average Structures of t-Butyl Chloride and 9D-t-Butyl Chloride Determined by Gas-Phase Electron Diffraction

The structure of t-butyl chloride has been determined by electron diffraction. The results obtained are in good agreement with the previous structure determination by Momany, Bonham, and Druelinger. This structure is shown to be consistent with the microwave rotational constants determined by Lide and Jen in spite of the fact that the rg distance for the C–Cl bond (1.828±0.005 Å) is quite different from the rs microwave distance (1.803±0.002 Å). The remaining structural parameters were determined to be C–C (1.528 Å), C–H (1.102 Å), ∠ ClCC (107.3o), ∠ CCH(110.8o), ∠CCC (111.6o), and ∠ HCH (108.1o). A simultaneous investigation of the structure of the deuterated species suggests slight secondary isotope effects on the C–C (ΔC–C=0.0010±0.0007-Å) and C–Cl (ΔC–Cl=0.0010±0.0015-Å) distances. Observed mean amplitudes of vibration are found to be consistent with values calculated from the harmonic force field of Hüttner and Zeil.