Synthesis of dppmCN to assign chemical shift values to methylene hydrogens of dppm in cis-Re2(O2C-4-C5H4N)2Cl2(dppm)2

The main goal of this research was to assign chemical shift values to the methylene hydrogens of dppm in cis-Re2(O2C-4-C5H4N)2Cl2(dppm)2. When this compound was characterized using nuclear magnetic resonance spectroscopy, it was observed that one of the hydrogens resonated at an unusually high chemical shift, 6.3 ppm. Before the cause of the high shift can be known, assignments have to be made. To make these assignments a new complex will be synthesized where one of the hydrogens of one of the dppm molecules has been replaced by CN. Attempts to prepare dppmCN using the procedure of Braun, L. et al. (Dalton Trans. 2007, 1409-1415) were unsuccessful. However, when the base used by Braun, L. et al., viz., n-butyllithium, was replaced with lithium diisopropylamine, dppmCN was successfully prepared in 37% yield. Future work will consist of using dppmCN to synthesize cis-Re2(O2C-4-C5H4N)2Cl2(dppm)(dppmCN), a compound that may provide a solution to the assignment problem