Infrared spectrum of potassium-cationized triethylphosphate generated using tandem mass spectrometry and infrared multiple photon dissociation

Tandem mass spectrometry and wavelength-selective infrared photodissociation were used to generate an infrared spectrum of gas-phase triethylphosphate cationized by attachment of K+. Prominent absorptions were observed in the region of 900 to 1300 cm(-1) that are characteristic of phosphate P=O and P-O-R stretches. The relative positions and intensities of the IR absorptions were reproduced well by density functional theory (DFT) calculations performed using the B3LYP functional and the 6-31+G(d), 6-311+G(d,p) and 6-311++G(3df,2pd) basis sets. Because of good correspondence between experiment and theory for the cation, DFT was then used to generate a theoretical spectrum for neutral triethylphosphate, which in turn accurately reproduces the IR spectrum of the neat liquid when solvent effects are included in the calculations. Copyright (C) 2009 John Wiley & Sons, Ltd.