Interesting Occurrences of Polymorphs
Walter McCrone stated that "every compound has different polymorphic forms, and that, in general, the number of forms known for a given compound is proportional to the time and money spent in research on that compound."
Crystal polymorphs can disappear. There have been cases of individual laboratories growing one crystal form. They then grow a different crystal form, and are unable to make the first form again. Also, they find that they can make the first form again, but it now converts to the second form over time. The drug paroxetine was subject to a lawsuit that hinged on such a pair of polymorphs. An example is known when a so-called "disappeared" polymorph re-appeared after 40 years. These so-called "disappearing" polymorphs are probably metastable kinetic forms.
Read more about this topic: Polymorphism (materials Science)
Famous quotes containing the words interesting and/or occurrences:
“I have no plans to call on you, Clarice. The world’s more interesting with you.”
—Ted Tally, U.S. screenwriter, and Jonathan Demme. Dr. Hannibal Lecter (Anthony Hopkins)
“If to be venerated for benevolence, if to be admired for talents, if to be esteemed for patriotism, if to be beloved for philanthropy, can gratify the human mind, you must have the pleasing consolation to know that you have not lived in vain. And I flatter myself that it will not be ranked among the least grateful occurrences of your life to be assured that, so long as I retain my memory, you will be thought on with respect, veneration, and affection by your sincere friend.”
—George Washington (1732–1799)