sandwich and hamburger molecule

  

  I think there are too much organic compounds in the previous posts; though organic compounds indeed have a much greater variety and flexibility in structure, inorganic compounds do also have something to show! So this week I would like to introduce some classes of inorganic compounds with interesting structures. The first class is sandwich compound, they have structure like this:

   The dash lines between the metal and the ring up and down are not actually chemical bonds, they are  just simplified symbols to represent a special type of coordination bond. 

   Still one thing worth mentioning is that though the “bread” of the sandwiches are different (pentagon, hexagon, octagon…), they are all aromatic (芳香). This property stabilizes the overall compound structure.

   If you have no idea what previous sentences are talking about, don't be afraid, just appreciate their structure~

Of course there is “half sandwich” compound, which is also called "piano stool" compound due to their structure. Here’s one example:

And this is piano stool haha:

    What’s more, there is "mutlidecker sandwich" compound, just like big mac! Take a look at the structure:

  However, there are more classes of compound, as the image below shows, and I only mention a narrow range of them today! Hope you can have a deeper insight into molecular structure after reading my post~