Molecular structure of bromoform as determined by a joint analysis of electron diffraction and microwave data

The gas phase molecular structure of bromoform has been studied by electron diffraction. By a joint analysis of the diffraction results and the moments of inertia for CH79Br3, CD79Br3, CH81Br3, and CD81Br3 obtained by Williams et al., the bond distances in r sub(g) and the bond angles in phi sub(av) have been determined as follows: γsub(g)(C-Br) = 1.924 +- 0.005 A, r sub(g)(Br...Br) = 3.175 +- 0.003 A, r sub(g)(C-H) = 1.111 +- 0.046 A, phi sub(av)(BrCBr) = 111.7 +- 0.40, and phi sub(av)(HCBr) = 107.2 +- 0.50. The uncertainties represent the estimated limits of error. The anharmonicity parameter of the Morse-type potential, a3, for the nonbounded Br...Br atom pair has been estimated as -1.3 +- 0.9 A-1. (author)