A proposed 'metabolism' for a hydrocarbon assembler

Molecular manufacturing should let us synthesize most arrangements of atoms that are consistent with physical law. Assemblers have been proposed as a means of accomplishing this objective. They would be able to build a wide range of useful products as well as copies of themselves. A simpler though less general proposal is a hydrocarbon assembler, restricted to manufacturing relatively stiff hydrocarbons. The design and analysis of such an assembler should be substantially simpler than that of a more general assembler. In this paper, we consider the 'intermediary metabolism' of a hydrocarbon assembler, i.e. the set of reactions that permit processing of the feedstock molecules and their conversion into molecular tools (positionally controlled carbenes, radicals, and other reactive species). The specific feedstock molecule analyzed is butadiyne (a linear molecule, C4H2, also known as diacetylene; not to be confused with the more common but chemically distinct nonlinear molecule butadiene: C4H6).