Modelling GO, as produced by modifications of the Hummers' method, remains challenging. This is not least because of the heterogeneity of the GO structure, which contains hydroxyl, epoxy and carboxylic acid residues as the oxygenated groups formed during the oxidation of graphite, as captured by the Lerf-Klinowski model. In this model the carboxylic acid functions tend to localise at the edge of sheets while the rest tend to occur on sp 3 -hybridised carbons in the basal plane. While the Lerf-Klinowski model has been used to good effect in computational studies, it tends to assume a random distribution of oxidised functionalities throughout the structure and this is open to question, not least because disruption of the sp 2 framework by oxidation means that proximate regions are more prone to subsequent oxidation. This leads to oxidised islands in otherwise unmodified seas of graphitic structure. Accordingly, more sophisticate models have been developed which capture these features. Against this backdrop, the authors used a small, highly simplified (C54(OH)7) precursor model, 5, with protonated epoxy groups as the sole O-containing functions. Specifically, the precursor 5 has 6 protonated epoxy groups sitting over the centres of C6 rings at the edges of the ring and a 7 th sitting over the central C ring (Figure ). The model was not capped with hydrogen atoms but retained unphysical open shell carbon atoms at its edge. Two of these sheets were then arranged on either side of a dication of aminoferrocene ; see below for discussion on the likely validity of this Fe(IV) structure in this context) and then the structure was 'relaxed' to give the unusual structure, 6, shown in Fig. with two free hydroxy radicals between 1 2+ and the two GO sheets. The two GO layers 'bulge' away from the aminoferrocene/hydroxyl radical region, leading the authors to speculate that the magnetic properties might be modulated by varying pressure. We note that this extrusion of the hydroxyl radicals is critical to the authors' arguments, not least as it is used to account for 'metalisation' by partial electron transfer from 1 to the hydroxyl radicals. This of course is only valid if the free hydroxyl radicals are present in the structure, with at least twice as many available as the amount of intercalated 1 2+ . In practice, there will be very few free hydroxyl radicals in GO prepared by the modified Hummers' method used by the authors: these would have been removed during work-up or would have long since reacted directly with the GO. Therefore, the only way in which this model could prove viable is if the presence of 1 2+ were itself responsible for the extrusion of the free hydroxy radicals. This proves not to be the case, simply taking the C54(OH)7 precursor 5 and subjecting it to geometry optimisation in isolation (PBE-d3bj/def2-TZVP) leads to the same extrusion of the central hydroxy radical (along with the migration of the remaining 6 hydroxyls to the periphery), as shown in Fig 2c . It should be noted that a frequency calculation reveals this structure to be a complex saddle point rather than a minimum on the potential energy surface, 31 with imaginary stretches associated with several OH wagging processes, but this does not impact significantly upon the key conclusion. The extrusion of the free hydroxy radicals is merely a consequence of the unphysical nature of the starting model 5 (Fig. ) and has nothing to do with the presence or absence of any intercalating species. Therefore, any explanation for the observed magnetic properties that requires the presence of periodic hydroxy radicals is unfounded both experimentally and computationally. The authors describe "significant internal pressure induced by the presence of the aminoferrocene […] which leads to the isolated graphene sheets taking on a spherical shape". We find this bowing is not a consequence of the aminoferrocene moiety, as is readily demonstrated by modelling the system in the absence of the free hydroxy radicals. Geometry optimisation (PBE-d3bj/def2-SVP(def2-TZVP on Fe)) of three models (6 -IS 8; IS = intermediate spin) with intercalated 1, 1 + or 1 2+ (Fe(II), Fe(III) and Fe(IV), figure 2d -f respectively) gives structures that clearly show no bowing of the GO layers. Instead, the structures are largely unremarkable, formed by p-stacking of the cyclopentadienyl rings of the aminoferrocene moieties with the GO layers. Separately, we also modelled both a chemically more realistic 33 hydrogenated version of 6 with H atoms added to the peripheral carbons (9) and the effect of changing spin-state in 8. Neither modification had a profound effect on the overall structure of the species obtained. Looking at the oxidation states of the putative intercalating aminoferrocenes, 1 and 1 + are chemically reasonable under the conditions described, 5 but the dication 1 2+ is not. This was modelled apparently to introduce an appropriate level of magnetic anisotropy, however ferrocene dications are remarkably rare due to their inherent extreme reactivity. To date, the only crystallographically characterised Fe(IV) ferrocene is [Fe(C5Me5)2] 2+ , which is extremely air-and moisture-sensitive and decomposes in organic solvents. Indeed, it can only be prepared and handled in SO2 and is produced by the oxidation of [Fe(C5Me5)2] with powerful oxidising agents such as AsF5, SbF5, and ReF6. No such potent oxidising agents are present in the system reported: 1 2+ would be highly unlikely to form under their conditions and even it did, it would not subsequently survive the reported reaction media.