title: Ab initio studies on the tri- and diphosphate fragments of adenosine triphosphate.
abstract: Pyrophosphate prototypes such as methyl triphosphate and methyl diphosphate molecules in their different protonation states have been investigated at high levels of quantum chemical calculations. The optimized geometries, the thermochemistry of the hydrolysis and the molecular orbitals contributing to the high energy of these compounds have been analyzed. These investigations provide insights into the "high energy" character of ATP molecule. Further, the dependence of vibrational frequencies on the number of phosphate groups and the charged states has also been presented. These results can aid the interpretation of spectra obtained by experiments on complexes containing pyrophosphate prototypes.
authors.affiliation: Molecular Biophysics Unit, Indian Institute of Science, Bangalore, 560012, India.
authors.forename: Priti
authors.initials: P
authors.lastname: Hansia
authors.forename: Nandini
authors.initials: N
authors.lastname: Guruprasad
authors.forename: Saraswathi
authors.initials: S
authors.lastname: Vishveshwara
mesh_terms: D000255:Adenosine Triphosphate / Q000737:chemistry*; D006868:Hydrolysis; D008956:Models, Chemical; D010710:Phosphates / Q000737:chemistry*; D011789:Quantum Theory; D012680:Sensitivity and Specificity; D017550:Spectroscopy, Fourier Transform Infrared / Q000379:methods; D013816:Thermodynamics; D014732:Vibration
chemical_list: D010710:Phosphates; D000255:Adenosine Triphosphate