A question came up in class from one of my chemistry students. He asked what the largest, non-crystal, non carbon-based, molecule is. We ruled out complex proteins, DNA, and other polymers, as well as crystalline structures and metals from the list. I didn't have an answer for him, so I looked it up but could not find a definite answer. I found two threads on Reddit, listed below. Polyoxometalates come up, but without any specifics. I know "largest" can be subjective, so please specify if the molecule is "largest" because of its physical size or because of its mass.
https://www.reddit.com/r/chemistry/comments/2phl4s/whats_the_largest_inorganic_molecule_you_know/
https://www.reddit.com/r/askscience/comments/i6v07/what_is_the_biggest_noncrystalline_inorganic/