Vibrational spectroscopic study of DL-methionine dihydrogen phosphate

The two methionine cations in the asymmetric part of the unit cell of bis(D L-methionine dihydrogen phosphate) have different conformations. This, toge ther with the different environments seen by the two -CH2- groups in each s keleton cause several of the group wavenumbers to occur as doublets or as b road bands. The anion contains two dissimilar P-O bonds, which distorts the phosphate tetrahedron. Due to this, the stretching wavenumbers appear as d oublets. There is extensive hydrogen bonding in the system in all three cry stallographic directions and this is responsible for the changes in the pos ition and intensity of several bands. Fermi resonance has also been observe d. (C) 2001 Elsevier Science B.V. All rights reserved.