Photoelectron spectra and bonding in phosphorus compounds
Abstract
Bonding in Phosphorus Compounds1: Reduction Potentials of R2(Y)P-substituted Aromatic π Systems2 and Gasphase Syntheses of 18 Valence Electron Molecules X-P=Y3,4
Abstract An up to date concept of bonding in phosphorus compounds, which has to consider the individual molecular states, their dynamics and reaction channels, is illustrated by representative examples. The reduction potentials of R2(Y)P-substituted π systems to their radical anions, measured under aprotic conditions and discussed by first order perturbation, yields a sequence of increasing acceptor effects ranging from R2P to R3P®. The gasphase syntheses of novel molecules like H3C-P=CH2, Cl-P=O or Cl-P=S, partly by surface reactions, has been optimized by photoelectron spectroscopic real-time analysis. Their radical cation state ionization patterns are assigned by quantum chemical calculations, which allow to rationalize the bonding to the only doubly coordinated P center.
Relative Intensity Measurements in Microwave Spectroscopy
A method is described for the measurement of peak intensity ratios of gas phase microwave absorption lines. Large errors associated with multiple reflections in the waveguide have been eliminated by careful design and the use of ferrite isolators. Detector nonlinearities have been neutralized by using a precisely calibrated step attenuator allowing both lines involved in a ratio to be displayed with approximately the same amplitude. Means of minimizing additional sources of error are discussed. Application of the method to a number of problems indicates that ratios accurate to a few percent can be obtained.