Molecular mechanics calculations of conformational structures, energies and torsional force constants in some bromopropenes and bromobutenes

Abstract

Gas-phase data on conformational energies and structures of the molecules BrH 2CHCCH 2, BrH 2CBrCCH 2, BrH 2C(CH 3)CCH 2 and BrH 2CCH 2HCCH 2 are used to establish parameter values for the nonbonding atom ⋯ atom interactions Br ⋯ C( sp 2) within the Morse potential formulation. Torsional potentials are calculated for the molecules mentioned above and in addition for cis- and trans-BrH 2CHCCHBr, transBrH 2CHCC(CH 3)H, (BrH 2C) 2CCH 2, cis-BrH 2CHCCHCH 2Br and CH 3BrCHHCCH 2. Torsional force constants for the molecules are obtained. A comparison with the corresponding chloro compounds is made.