Pentacene is synthesized from benzene, and the primary source for benzene is currently petroleum. It doesn't have to be, but benzene has always been a relativel

Pentacene is synthesized from benzene, and the primary source for benzene is currently petroleum. It doesn't have to be, but benzene has always been a relatively cheap "garbage" byproduct of other products (first coke, then petroleum fuels). It is unlikely that over the long term extraction of fossil fuels would be a cost-efficient means of deriving chemicals that are now heavily subsidized by the primary products; bacterial synthesis would probably much more practical. That is to say one shouldn't dismiss non-fuel petrochemicals simply because the current cheapest source is petroleum -- it won't always be unless the demand for petrochemical fuels (or coal/coke) remains high. Ironically, then, things that are now petrochemicals could spell the end of the petrochemical industry if they contribute to a reduction in demand for fuel.