The diatomic species C2 has a long and literally colourful history, one nicely summarised recently. Much of the known chemistry and particularly the spectroscopy relates to the gaseous species at high temperatures, but the very high reactivity has also meant that ambient temperature generation in the condensed phase and the mechanism of subsequent reactions has hitherto been less studied. Interest in this species has been particularly sparked in the last decade by renewed discussion of its chemical bonding in the form of a proposal that it sustains a quadruple bond between the carbons as in C⩸C, a claim that generated much stimulating debate and continues to do so unabated. Most recently, the attention has extended to species with quadruple bond patterns between carbon and other elements such as C⩸Fe or related main group elements with similar four-fold bond characteristics as in B⩸Rh or Si⩸Rh. Such diverse reports raise the distinct possibility that room temperature/solution studies of species containing quadruple bonds to carbon will become possible and perhaps even routine. In this context then, the recent proposal of a room temperature chemical synthesis in the condensed phase on a relatively rapid timescale (~minutes) of C2 itself was particularly significant, since this would open an avenue for exploring the reactivity of carbon in this unusual bonding state in new media and a new temperature range. The reaction was thought to proceed at ambient or low temperatures from the transient zwitterionic intermediate 2, formed by treating precursor 1 with a source of fluoride anion. Unimolecular fragmentation of 2 would then produce iodobenzene and free singlet state C2 (Figure ). It should be noted that other reagents that deliver a dicarbon fragment have been reported, although there the mechanism was not thought to involve any free C2. Likewise dicarbon stabilized by a single phosphine ligand has been characterised which can undergo, inter alia, an interesting intermolecular C-H activation upon thermolysis. Experiments trapping 2 in solution with either 9,10dihydroanthracene or galvinoxyl radical (Figure ) enabled isolation of products from which participation of free C2 was inferred. The same conclusion also following from detection of polymeric carbon products such as amorphous carbon and even C60. An experiment carried out using solid reagents putatively produced "C2 gas", as inferred by using argon to flush any volatile products out of the reagent flask and into a second flask, where they were again observed to be trapped using solid galvinoxyl. Further pertinent experimental observations are the reported results of isotopic substitution in 2. In dichloromethane solutions, it was asserted that 13 C⩸C 12 , as apparently formed from labelled 2 and trapped using galvinoxyl, results in a 71:29 product ratio in favour of a C label