The number of structurally characterized group 6 metal complexes with seven isocyanide ligands is very limited. The crystal structures of [Mo(CN t Bu)7][PF6]2, [W(CN t Bu)7][W6O19], [W(CN t Bu)7][PF6]2, and [Mo(CNMe)7][BF4]2 have been reported in the 1970s and beginning 1980s. For the latter, the corresponding tungsten compound is only briefly mentioned in the literature. For molybdenum, also the crystal structures of [Mo(CNR)7][PF6]2 are known (R= cyclohexyl, phenyl). Interestingly, also a seven-coordinate chromium complex [Cr(CN t Bu)7][PF6]2 exists. In contrast, octacyanometalates [M(CN)8] 4-/3-(M= Mo, W) have been frequently used as building blocks in coordination chemistry. Most relevant are their applications in magnetochemistry, for example for the preparation of photomagnetic materials and single-molecule magnets. Since octacyanometallates [M(CN)8] 4-/3-(M = Mo, W) are known, the question arises whether it could be possible to synthesize the fully alkylated complexes with eight isocyanide ligands, as Unfortunately, he was not able to determine the correct structure due to the lack of suitable spectroscopic methods. Almost 40 years later, Latka reported that this reaction gives [W(CN)4(CNMe)4]•2 H2O. Soon after, the triangular-dodecahedral structure of [Mo(CN)4(CNMe)4] in the solid state and other alkylated derivatives were reported. To achieve eightfold methylation, it seemed necessary to choose a drastically more powerful methylating agent. Recently, we reported that eight-fold protonation of [M(CN)8] 4-(M=Mo, W) to the corresponding [M(CNH)8] 4+ tetracations is achieved under superacidic conditions by a combination of anhydrous hydrogen fluoride with the super Lewis acid SbF5. Similarly, the combination of MeF with AsF5 in liquid SO2 as solvent is known to generate the extremely powerful methylating agent [MeOSO][AsF6]. However it has been rarely used in recent times.