Flexibility of six-membered O/P/O/C/C/C rings in the solid state. The chair-skew ring flipping.
What is it about?
We have shown the conformational flexibility (chair-skew ring flipping) of the six-membered O/P/O/C/C/C ring in the solid state, as well as the ease of modifying the ring puckering and overall molecular shape in response to temperature changes.
Why is it important?
Six-membered O/P/O/C/C/C rings are constituents of a number of biologically important molecules, such as 3':5'-cyclic nucleotides, for example cAMP. In the solid state, monocyclic phosphates containing a tetra-bonded P atom generally exist in the chair conformation, while the skew conformation was shown to be important in cellular media and may play a role within an enzyme active site. Therefore, searches for crystals containing cyclic phosphates in the non-chair conformation, allowing direct observation of the geometrical parameters , and looking for the structural changes during the chair-skew ring flipping, is quite important from structural point of view.