Spectroscopic Reassignment and Ground-State Dissociation Energy of Molecular Iodine

Abstract

Reanalyzing some early bandhead data for I2[B 0u+(3Π)], an improved value of the ground-state dissociation energy is found to be D0 = 12 440.9 ± 1.1 cm−1, differing significantly from the previously accepted value of Verma, 12 452.5 ± 1.5 cm−1. This result implies that the final state of one of the uv resonance series reported by Verma must have a rotationless potential maximum some 13.1 ± 1.4 cm−1 high. It is further shown that the original electronic assignment of this state as ground-state X 0g+(1Σ) is implausible. A reassignment as 0g+(3Π) is proposed, and the nature of the 0g+(3Π) potential is considered.