X-ray Diffraction as a Method to Find Chemical Structures is 100 Years Old

Chemical and Engineering News is the American Chemical Society's news magazine for its members.  A recent issue (August 14, 2014) celebrated the 100th birthday of X-ray diffraction as a method to determine three dimensional chemical structures of molecules, in essence allowing chemists to "see" molecules for the first time.  As part of the celebration they invited readers to post their favorites structures.  These can be found at http://cen.xraycrystals.org/favorite-crystal-structure-responses.html/.  Here is one pretty one:

The name of this molecule is ferrocene and its structure with an iron atom sandwiched between two hydrocarbon rings was revolutionary at the time.  Go check out some of the other examples.