Molecule, design desired chemical

Design of Molecule or Mixture for a Desired Chemical Product... 

Obtaining relevant physicochemical parameters. The choice of physicochemical parameters to relate to MDS spaces is crucial if the properties found to be mathematically important are indeed appropriate chemical predictors for future design of molecules with desired flavor properties. Unfortunately, we often have no idea what physicochemical properties are indeed important, although many of the parameters described in the examples below as well as those given in Table I (see are probably... 

This is also a two-step procedure similar to that of selecting a desired chemical from a list of candidate molecules. Unlike the selection from an existing set of compounds, the design of compounds implies the synthetic stipulation of molecules for which there are no experimental data of their physical properties. Therefore, using some of the available estimation techniques, different approaches have been proposed in the past and will be discussed in the following paragraphs. 

Important steps of this process are (a) selection of the set of molecules the modeling procedure is applied to, and the set of molecular descriptors that will define the model chemical space (b) selection of the training set for the model estimation and the test set for model validation (c) application of the validated model(s) to design new molecules with desirable properties and/or predict the response of interest for future molecules, paying attention to the applicability domain of the model. 

Time-domain spectroscopies entail a major shift in emphasis from traditional spectroscopies, since the experimenter can control, in principle, the duration, shape, and sequence of pulses. One may say that traditional, CW spectroscopy, is passive—the experimenter attempts to study static properties of a particular molecule. Coherent pulse experiments are active in that, given a set of molecular properties (which may in fact be known from various spectroscopies), one tries to arrange for a desired chemical product, or to design a pulse sequence that will probe new molecular properties. The time-dependent quantum mechanics-wavepacket dynamics approach developed here is a natural framework for formulating and interpreting new multiple pulse experiments. Femtosecond experiments yield to a particularly simple interpretation within our approach. 

K. G. Joback, Designing Molecules Possessing Desired Physical Property Values, digest of doctoral thesis, Department of Chemical Engineering, Massachusetts Institute of Technology (June 17, 1989). 

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