These low energy bimolecular mechanisms bring into question whether free C2 as generated by unimolecular fragmentation of 2 actually participates in the solution-phase reactions. It also raises the issue of what is happening in the reported experiment where a flask containing solid-state reactants is flushed by argon gas into a second flask containing galvinoxyl. The assumption was that the only species sufficiently volatile to be transferred between flasks would be "C2 gas", which would then be trapped and crucially that 2 itself was too involatile to be so transferred. An experiment whereby 2, via the aryl group, be covalently anchored to a solid-phase support and placed in the first flask would eliminate any possibility that it is 2 and not C2 that is being transferred and trapped in the second flask.