Low-Field Flow <sup>31</sup>P NMR Spectroscopy for Organometallic Chemistry: On-Line Analysis of Highly Air-Sensitive Rhodium Diphosphine Complexes
Laura Tadiello, Hans‐Joachim Drexler, Torsten Beweries
Abstract
Low-field flow NMR spectroscopy is a promising on-line technique for reaction monitoring. In the field of organometallic chemistry, involving air- and moisture-sensitive complexes, its application is however still limited. In particular, low-field flow 31P NMR spectroscopy is an attractive technique that could allow for routine benchtop monitoring of stoichiometric and catalytic transformations involving sensitive organophosphorus species. Herein, we present the practical aspects of the development of a customized low-field flow NMR setup and demonstrate its utility for reactions of highly oxygen-sensitive rhodium bis(phosphine) complexes, e.g., [Rh((S,S)-DIPAMP)(MeOH)2]BF4 and [Rh((R)-BINAP)(μ-Cl)]2. The investigation is carried out in real time under preparative conditions, allowing the formation of the desired organometallic species without degradation.