(463d) An Algebraic Approach for Solving Molecular Design Problems Using Higher Order Property Operators

Conventional molecular design methodologies involve selection of molecules from among a predefined database therefore limiting the solution to only those listed components. The decisions in these cases are based only on process knowledge and/or experience and thus an optimal solution may not be obtained. To overcome this, the concept of reverse problem formulations based on property operators has been developed to identify the molecular structures that match the property targets. These property operators are combined with property estimation models based on Group Contribution Methods. Earlier works have introduced group contribution methods (GCMs) and second order estimation for solving the molecular design problem within the property integration framework. In this work, the accuracy of the property prediction is enhanced by improving the techniques for enumerating higher order groups. This method results in a remarkable decrease in the combinatorial size of the design problem. Incorporation of higher order enumeration techniques increases the efficiency of property prediction and thus the application range of the group contribution methods to molecular design problems. The molecule generation method employed enables the identification of isomers by incorporating a check for the possibility of nonexistence of each higher order group in each enumerated combination. Since the algorithm should be able to solve for any number of properties, an algebraic approach is used to handle the situation and generate possible compounds within the required property range. This contribution will use a case study to highlight the principles of the developed methodology.