Combination of Resonance and Non‐Resonance Chiral Raman Scattering in a Cobalt(III) Complex.

Yang, Qin; Bloino, Julien; Šestáková, Hana; Šebestík, Jaroslav; Kessler, Jiří; Hudecová, Jana; Kapitán, Josef; Bouř, Petr

Resonance Raman optical activity (RROA) spectra with high sensitivity reveal details on molecular structure, chirality, and excited electronic properties. Despite the difficulty of the measurements, the recorded data for the Co(III) complex with S,S‐N,N‐ethylenediaminedisuccinic acid are of exceptional quality and, coupled with the theory, spectacularly document the molecular behavior in resonance. This includes a huge enhancement of the chiral scattering, contribution of the antisymmetric polarizabilities to the signal, and the Herzberg‐Teller effect significantly shaping the spectra. The chiral component is by about one order of magnitude bigger than for an analogous aluminum complex. The band assignment and intensity profile were confirmed by simulations based on density functional and vibronic theories. The resonance was attributed to the S0→S3 transition, with the strongest signal enhancement of Raman and ROA spectral bands below about 800 cm−1. For higher wavenumbers, other excited electronic states contribute to the scattering in a less resonant way. RROA spectroscopy thus appears as a unique tool to study the structure and electronic states of absorbing molecules in analytical chemistry, biology, and material science.

RAMAN scattering; COBALT; MATERIALS science; RESONANCE; OPTICAL resonance; MOLECULAR structure; MATHEMATICAL complexes

Angewandte Chemie, 2023, Vol 135, Issue 45, p1

0044-8249

Academic Journal

10.1002/ange.202312521