What is the size of iron pentacarbonyl, methylcyclopentadienyl-manganese-tricarbonyl, or dicobalt octacarbonyl? Where could I find a source on this information? I am aiming to fit the above carbonyls into a 29-34 angstrom pore, but I'd like to know if it's even possible given the size of the molecules. Wikipedia offers numbers based on a paper published in Inorganic Chemistry in 1977. The Co-Co distances is 2.5 angstroms and the Co-CO appears to be in the area of 1.8 angstroms. Does simple math tell me the diameter is no greater than 6.5 angstroms? How does the size of the atoms come into play? Thank you in advance!