Donna Blackmond

Blackmond has pioneered the methodology of Reaction Progress Kinetic Analysis (RPKA), which is used for rapid determination of concentration dependences of reactants.[1] RPKA allows for in situ measurements to produce a number of rate equations that enable analysis of a reaction using a minimal number of experiments. The purpose for this type of analysis is to help understand what the driving force of a reaction might be and describe possible mechanistic pathways.[2] This technique distinguishes rate processes occurring on the catalytic cycle from those occurring off the cycle. Notable applications of RPKA include asymmetric hydrogenation, asymmetric organocatalytic reactions, palladium catalyzed carbon-carbon and carbon-nitrogen bond forming reactions, and transition-metal catalyzed competitive reactions.[1]

Nonlinear effects describe the non-ideal relationship between enantiomeric excess (ee) of products of a reaction and the ee of the catalyst, a phenomenon first observed by Henri Kagan. Kagan developed mathematical models to describe this non-ideal behavior, ML_n models.[3] Blackmond has performed studies that have led to an understanding of reaction rate and its relationship to catalyst ee. Many proposed mathematical models have been tested in the Blackmond lab, which have helped determine possible mechanistic features of reactions, including the Soai reaction.[4] The Soai reaction is of abiotic synthetic interest because it is an autocatalytic reaction, which rapidly produces a large amount of enantiopure products.[5] Blackmond was the first to use Kagan's ML₂ model to study the non-linear effects of this reaction. She was the first to conclude that a homochiral dimer was the active catalyst in promoting homochirality for the Soai reaction.[4]

More recently, Blackmond has extended kinetic models to describe the origin of biological homochirality. She has shown solutions of mostly enantiopure amino acids can be produced from nearly racemic mixtures via solution-solid partitioning of the enantiomers. The discovery that eutectic mixtures could be manipulated, depending on the components of the mixture, allows for changes to the crystal structure and solubility of substances. Amino acids crystallize in one of two ways, as a mixture of D and L enantiomers (racemic compound) or as separate enantiomers (conglomerate) .[6] For nonracemic, nonenantiopure mixtures of molecules under ternary phase equilibrium, partitioning of enantiomers occurs between the liquid and solid phases depending on the form that the crystals take.