COLD ION SPECTROSCOPY OF B₁₂ DERIVATIVES: STRETCHING THE LIMITS OF THEORETICAL INTERPRETATION

Abstract

Aryl-corrins is a class of B 12 derivatives that embodies "antivitamin" properties and represents a biologically important class of compounds that hence demands investigation. In our previous study, we experimentally determined bond strength in a series of aryl-corrins by the threshold CID experiments and compared these BDE's with those calculated with DFT. [1] We found that the computed BDEs were very much dependent on the chosen structure. Given that aryl-cobinamides have many side chains that increase their conformational space, and that the question of a specific structure, measured in the gas phase was important for further evaluation of our T-CID experiment, we proceeded to analyze structural properties of arylcobinamides using CIVP spectroscopy. We explored BOMD simulations with the semi-empirical GFN-xTB methods[2-3] for interpretation of experimental spectra in these conformationally flexible systems.