Pyridylidene amine (PYE) ligands store and release hydride when coordinated to an iridium center through reversible de- and re-aromatization, as known for the NAD+/NADH couple.
The iridium PYE system is an efficient catalyst for the selective hydrogenation and deuteration of carbonyl and imine functional groups with high atom economy.

This work was carried out in the group of Prof. Dr. Martin Albrecht.

References:

• N. Lentz, S. Reuge, M. Albrecht;
  "NADH-Type Hydride Storage and Release on a Functional Ligand for Efficient and Selective Hydrogenation Catalysis"
  ACS Catal., 2023, 13(14), 9839-9844; doi:10.1021/acscatal.3c02343.
• J. J. Race, M. Albrecht;
  "Pyridylidene Amines and Amides: Donor-Flexible Ligands for Catalysis"
  ACS Catal., 2023, 13(14), 9891-9904; doi:10.1021/acscatal.3c02203.