Metal Ligand Multiple Bonds PDF Download

Atom transfer reactions such as HAT (hydrogen atom transfer) and OAT (oxygen atom transfer) offer a method for efficient bond formation in a single step. Extending this concept, this single atom delivery also has the potential to provide an effective route to otherwise inaccessible ligands. In this work, we investigate the utility of the tris(carbene)borate iron(IV) nitride, PhB(iPr2Im)3Fe≡N, as a viable nitrogen atom source for the assembly of new ligands. In one embodiment of this approach, an unusual carbon atom transfer reaction leads to the assembly of a C≡N− ligand when two equivalents of bis(diisopropylamino)cyclopropenylidene (BAC) carbene are added to PhB(iPr2Im)3Fe≡N. This strategy is extended to access of the elusive gas molecule, P≡N, which is assembled by using (N3N)Mo≡P (N3N = [N(CH2CH2NSiMe3)3]3−) and PhB(iPr2Im)3Fe≡N as P- and N-atom sources, respectively. These are the first structurally characterized compounds with this unique ligand. Photoisomerization of the P≡N ligand is observed in the solid-state and trapping of the N≡P linkage isomer reveals the fluxionality of this ligand in solution. Additionally, the bis(carbene)borate ligand framework is also explored as supporting ligand for the development of new metal-ligand multiply bonded complexes with the first structural characterization of an Fe(VI) compound, the highest oxidation state of iron, being achieved.