Peak Performance - Illustrating Selected Physical Methods

1 Peak Performance - Illustrating Selected Physical Methods 

There are a number of techniques that rely on applying specific protocols that lead to excitation and a resonance condition, reported experimentally as the appearance of a peak(s) in a spectrum by using appropriate instrumentation. It is beyond the scope of this textbook to develop the theory behind these many methods, but it is appropriate to illustrate two of the most common techniques - IR and NMR spectroscopy. 

Molecular shapes and 1H chemical shift patterns for chloro-ammine cobalt(III) compounds. Different environments for ammonia molecules in some complexes are defined by eq and ax subscripts, with the two types opposite different types of ligand leading to different magnetic environments and chemical shifts (8). 

Shapes and IR spectra patterns for chloro, O-nitrito and IV-nitrito cobalt(III) ammine compounds. The thick lines represent the vibrations associated with the coordinated ammonia molecule, whereas the thin lines represent the vibrations associated with the linkage isomer of nitrite (two and three bands for N- and O-bound isomers respectively). 

Electrospray ionization mass spectrometry (ESI—MS is a tandem technique it employs an electrospray ionization device (ESI) to produce bare ions in the gas phase from a supplied (usually aqueous) solution, and supplies these ions as a very dilute gaseous stream to the high vacuum chamber of a mass spectrometer, which is the analyser. This analyser sorts and detects ions by mass/charge ratio (mlz), as cations or as anions, and will report either on request. For coordination complexes, the ESI process can be sufficiently soft  

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