Thank you for sharing your question with the RG community. Although MOFs are coordination networks, they are still electrically neutral salt compounds in terms of their molecular formula.
n Co2+ (58.9) + 2n (C4H5N2)- (81.1) => [Co(C4H5N2)2]n (221.1)
For this reason, a maximum of 4.9 mmol Co-ZIF-67 can be formed from 4.9 mmol Co salt. The yield is then calculated as follows:
n = 100% * 0.7957 g / (0.0049 mol * 221.1 gmol-1) = 73%.
I would like to add that in many cases the metallic nodes are not single metal cations but consist of e.g. oxocentric metal clusters. In these cases, of course, the molecular formula is a bit more difficult to formulate.
Now I have another question, if I repeat the experiment with half times of all reagnatnts and solvent (I mean: cobalt nitrate hexahydrate =1.436g÷2; 2-mitylimidazole 3.244g÷2 and methanol 100ml÷2),it must results in approximately half yield (0.7957÷2)?