LOCAL RAMAN TENSORS IN ADENOSINE TRIPHOSPHORIC ACID

A polarized laser (488.0 nm) Raman spectroscopic measurement has been made on a single crystal of a disodium salt of adenosine triphosphoric acid (Na2ATP.3H2O) by the use of a Raman microscope. The crystal belo ngs to an orthorhombic system of the space group P2(1)2(1)2(1), and ha s dimensions of 10, 100 and 100 mum along the crystallographic axes a, b and c, respectively. For each Raman band in the 300-1800 cm-1 range , the scattering intensity ratio I(bb)/I(cc) of the bb and cc polariza tion components has been determined. For a few bands, the relative int ensities of the bc components were also estimated. To augment the data , the depolarization ratio of each Raman band of ATP has also been det ermined for its acidic (pH = 2.42) H2O and D2O solutions. From these e xperimental results, the shapes and orientations of the Raman scatteri ng tensors which are considered to be localized in the adenine-H+ port ion and in the phosphate portion of the molecule have been derived.