METHODS OF CHARACTERIZATION

Introduction

The aim of methods of characterization is to determine the results of a reaction. The levels of detail expected rely on the conditions and determines the range of techniques needed. One requires checking its purity and identity, if the aim has been to make a known compound. Fingerprinting methods measure a spectrum or some other property and compare it with results published for known compounds and presented in literature databases. Such type of methods may also depict whether impurities are exist, but it is frequently wanted to check the purity of the compound independently, for instance by elemental analysis. Though, if the compound prepared is a new one, more thorough investigation is suitable. By the elemental analysis, the stoichiometric formula may be found and the full molecular formula in principle by mass spectrometry (MS). MS combined with other spectroscopic methods, particularly infrared (IR) and nuclear magnetic resonance (NMR), might give valuable information about the functional groups present (example which atoms are bonded to which other ones) but do not give a complete structure determination. Comprehensive information on the positions of atoms, angles and bond lengths, etc. is most frequently determined by X-ray diffraction.

The purpose of this account is to summarize only the kind of information that can be obtained from the most significant techniques of characterization. Accounts of the principles behind them may be found somewhere else.