S. Schei, R. Hilderbrandt
Apr 1, 1985
Citations
0
Influential Citations
2
Citations
Journal
Journal of Molecular Structure
Abstract
Abstract A combined analysis of electron diffraction and microwave spectroscopic datz indicated that the symmetric P H conformer of 1-chloro-2-methylpropane is the most stable form. Data recorded at 28°C were found to be consistent with a conformational mixture containing 62(15)% of the asymmetric P C conformer which has 2 statistical weight of two, and 38(15)% of the P H conformer. This equilibrium mixture corresponds to a free energy difference Δ G = G(P c ) − G(P H ) = 0.5(1.6) kJ mol −1 . Molecular mechanics calculations based on the Morse-potential formulation on non-bonded interaction potentials also found the symmetric conformer to be energetically preferred by an energy difference of Δ E = 1.2 kJ mol −1 . The experimentally observed structural parameters of the asymmetric P c conformer ( r g distances and ∠ α angles) were as follows: τ (CC) avg = 1.532(2) A. r (CCl) = 1.791(3) A. r (CH) avg = 1.111(4) A, ∠CCCl = 111.1(9)°, ∠CCC avg = 110.9(7)°, ∠ClCH avg = 105.9(2.5)°, ∠CC methyl H avg = 113.1(1.2)°, and gaoche dihedral angle, 68(3)°.