Solvation structure of Li+ in concentrated LiPF6-propylene carbonate solutions

Time-of-flight neutron diffraction measurements were carried out for Li-6/Li-7 isotopically substituted 10 mol % LiPF6-propylene carbonate-d(6) (PC-d(6)) solutions, in order to obtain structural information on the first solvation shell of Li+. Structural parameters concerning the nearest neighbor Li+center dot center dot center dot PC and Li+center dot center dot center dot PF6- interactions were determined through least-squares fitting analysis of the observed difference function, Delta(Li)(Q). It has been revealed that the first solvation shell of Li+ consists in average of 4.5(1) PC molecules with an intermolecular Li+center dot center dot center dot O(PC) distance of 2.04(1) angstrom. The angle Li+center dot center dot center dot O=C bond angle has been determined to be 138(2)degrees.