Emerging Implications of the Concept of Hydricity in Energy-Relevant Catalytic Processes.

The "hydricity" of a species refers to its hydride-donor ability. Similar to how the pK is useful for determining the extent of dissociation of an acid, the hydricity plays a vital role in understanding hydride-transfer reactions. A large number of transition-metal-catalyzed processes involve the hydride-transfer reaction as a key step.

Heli(aza)cene: A Helical Molecular Tweezer with Tunable Intra- and Intermolecular Charge Transfer.

Non-planar fluorophores offer unique avenues of intra- and intermolecular energy transfer not available in their planar counterparts. We have rationally designed a molecular tweezer based on the pyridine-2,6-dicarboxamide framework having two structurally similar arms with extended π-surface. We termed this molecular tweezer as Heli(aza)cene (HAC) due to its spontaneous adoption of helical conformation stabilized by the amide and imine moieties present in it.

Small "Yaw" Angles, Large "Bite" Angles and an Electron-Rich Metal: Revealing a Stereoelectronic Synergy To Enhance Hydride-Transfer Activity.

Cyclometalated complexes are an important class of (pre)catalysts in many reactions including hydride transfer. The ring size of such complexes could therefore be a relevant aspect to consider while modulating their catalytic activity. However, any correlation between the cyclometalating ring size and the catalytic activity should be drawn by careful assessment of the pertinent geometrical parameters, and overall electronic effects thereof.

Switch in Catalyst State: Single Bifunctional Bi-state Catalyst for Two Different Reactions.

Disclosed here is a molecular switch which responds to acid-base stimuli and serves as a bi-state catalyst for two different reactions. The two states of the switch serve as a highly active and poorly active catalyst for two catalytic reactions (namely a hydrogenation and a dehydrogenative coupling) but in a complementary manner. The system was used in an assisted tandem catalysis set-up involving dehydrogenative coupling of an amine and then hydrogenation of the resulting imine product by switching between the respective states of the catalyst.