Rational design of complexes

Significant developments in the construction of multiporphyrin assemblies have been seen over recent years and many more will be seen in the years to come. No doubt the rational design of complex and intriguing supramolecu-... 

M. Yoneya, Toward rational design of complex nanostructured liquid crystals. Chem. Rec. 11, 66-76 (2011)... 

From this work one can derive high hopes for the future because by rational design of complexes and before the experiment analyses of steric interactions (using CPK models) a synthetic catalyst was designed in a rational manner. The rate accelerations must of course to be made better and the problem of catalytic turnover has not yet been solved. In the reactions described the catalyst is actually used in about 50-fold excess. Solutions for these problems are challenges for the future. 

The title of this three-part volume derives from a key theme of the book—the logic underlying the rational analysis of complex synthetic problems. Although the book deals almost exclusively with molecules of biological origin, which are ideal for developing the fundamental ideas of multistep synthetic design because of their architectural complexity and variety, the approach taken is fully applicable to other types of carbon-based structures. 

Litde is known about the stability of these porphyrins in O2 reduction, how this peripheral substitution affects O2 affinity of the metalloporphyrin, how the peripheral metal complexes perturb the energetics of various intermediates, and/or the kinetics of various steps or the mechanisms of O2 reduction by these porphyrins. At present, it remains to be seen if the strategy of coordinating metal complexes on the periphery of a metalloporphyrin can be exploited in the rational design of new ORR catalysts. 

In an elegant approach, Comba and co-workers initiated molecular-mechanics-based models that allow the rational design of ligand systems which are able to stabilize copper-dioxygen compounds. As a part of this investigation, complexes (241) (r = 0.12),223 (242) (r = 0.31),224 and (243) (r = 0.85)224 were synthesized and the reactivity of copper(I) complexes (Section 6.6.4.2.2(iv)) with dioxygen was investigated. 

Baldovi, J.J., Cardona-Serra, S., Clemente-Juan, J.M., Coronado, E., Gaita-Arino, A. and Palii, A. (2012) Rational design of single ion magnets and spin qubits based on mononuclear lanthanide complexes. Inorg. Chem., 51, 12565-12574. 

A better understanding of the theoretical background is another key for progress. A basic requirement for a more rational design of catalyst systems is to get more insight into the complex mechanism. The tools are in situ spectroscopic methods under reaction conditions. 

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