Molecular geometry of 2-nitrotoluene from gas phase electron diffraction and quantum chemical study

Abstract

The molecular geometry of 2-nitrotoluene has been determined by gas phase electron diffraction and quantum chemical computations at the MP2/6–31G∗ and Becke3-Lee-Yang-Parr (B3-LYP)/6–31G∗ levels of theory. Computed differences in CC bond lengths were utilized as constraints in the electron diffraction structure analysis. The scaled B3-LYP/6–31G∗ force field was used to generate the initial set of vibrational amplitudes. The electron diffraction study yielded the following bond lengths ( r g) and bond angles: C 1C 2, 1.405(8) Å; NO, 1.231(3) Å; C 1C 7, 1.508(8) Å; CN, 1.490(9) Å; C 7C 1C 2, 127.3(7)°; NC 2C 3, 113.8(6)°; C 1C 2C 3, 124.2(9)°; C 6C 1C 2, 114.8(6)°; C 5C 6C 1, 123.1(10)°; O-N-O, 124.9(3)°; ϕ(CN), 38(1)°. The structural features of the molecule point to steric interactions prevailing between the methyl and nitro groups.