What are the best techniques to determine/confirm what species of complex ions are in a solution? Also, can these be used to determine the concentration as well?
I know that a lot of solutions containing transition metal complexes have bright colors which indicates they are absorbing light in the visible spectrum. In this case I'm guessing you could simply use a uv-vis spectrophotometer and identify the species based on the wave-length of light being absorbed, and the concentration based on the intensity of light being emitted (beer-lambert's law)?
However, what could be used in the case of t-metal complexes that do not seem to absorb light in the visible spectrum (clear in solution), such as [TiF6]2-, [NbF6]-, etc...Does this require detecting spectra in the infrared range? If so, is there a technique that uses IR and/or Raman that can tell you concentration?