Question

After synthesizing a polymer containing 1-aza-18-crown-6 in the repeating unit, the goal is to compare the UV/Vis absorption differences upon chelation with metal ions (Cs, Co, Sr). The synthesized polymer is not soluble in commonly used solvents for metal salts, such as CH3CN, EtOH, or MeOH, but it dissolves in CH3Cl, CH2Cl2, toluene, chlorobenzene, THF, and dioxane. Metal salts that dissolve in THF are sought, but Cs2CO3 and CsF were unsuccessful. Given the solubility constraints, how can the UV/Vis absorption differences be compared effectively based on solution measurements?

a.Investigate alternative metal salts that are soluble in CH3Cl, CH2Cl2, toluene, chlorobenzene, THF, or dioxane for comparison in those solvents.
b.Attempt to modify the polymer to enhance solubility in CH3CN, EtOH, or MeOH for compatibility with commonly used metal salts.
c.Explore other metal ions that may form soluble salts in CH3Cl, CH2Cl2, toluene, chlorobenzene, THF, or dioxane for UV/Vis absorption comparison.
d.Consider alternative analytical techniques besides UV/Vis spectroscopy to characterize metal ion chelation in the polymer.

Answer 1

To compare UV/Vis absorption upon metal chelation, investigating alternative metal salts, exploring other metal ions, enhancing polymer solubility, or using alternative analytical techniques are viable strategies given the polymer's solubility constraints.

Step-by-step explanation:

To effectively compare the UV/Vis absorption differences of your synthesized polymer upon chelation with metal ions such as Cs, Co, and Sr, given the solubility constraints, you should consider the following options:

Investigate alternative metal salts that are soluble in the solvents like CH3Cl, CH2Cl2, toluene, chlorobenzene, THF, or dioxane. Identify metal salts that can dissolve in these solvents and conduct UV/Vis spectroscopy.

Explore other metal ions that might form soluble salts in your available solvents. This could provide a wider range of metals to test with your polymer.

Look into modifying the polymer to enhance solubility in more commonly used solvents like CH3CN, EtOH, or MeOH, which may require chemical modification of the polymer chain.

Alternative analytical techniques such as solid-state UV/Vis spectroscopy or even techniques like X-ray crystallography might be employed to assess the extent of metal ion chelation without relying on solution measurements.