The structural determination of reaction intermediates in organophosphonate anion chemistry has been stimulated by the extraordinary synthetic utility of these reagents. A great body of information about the solid-state and solution structures of phosphorus-stabilized anions has been collected during recent years, and include lithiated phosphonates, [2] phosphinoxides, phosphonamides, and thiophosphonamides. Even though a more detailed picture of the characteristics was achieved, and important conclusions about the related reactivity were drawn, there some open questions still remain. For example, a general problem in the reactions of such monolithiated reagents with electrophiles occurs when more acidic products are formed. This usually leads to the formation of unwanted side products. To overcome this limitation, an attractive strategy that takes advantage of a dianionic intermediate has been developed. Dicarbanions have already been used in several cases as supernucleophiles, and even in asymmetric reactions. Despite the synthetic value of these reagents, there is still a demand for more information about the structures. [6l, 7] Our interest in the study of such dilithiophosphonates is an extension of our work in the development and application of chiral substituted dianions. [6l] Here we present the first solid-state structure of a geminal dilithiated phosphonate.
These flash/quench methods provide a wide time window to study highly reactive forms of the enzyme. Both [P Cys Fe II (OH 2 )] À and [P .
Cys Fe III (OH 2 )] are formed in about 0.1 ms and persist for approximately 100 ms. Improved design of sensitizers, quenchers, linkers, and substrates may lead to even faster electron and hole injection into P450 and other redox-active enzymes.