(15)N and (31)P NMR Insights into Lactam-Lactim Tautomerism Activity Using cyclo-μ-Imidopolyphosphates
Hideshi Maki1, Daisuke Kataoka1, Minoru Mizuhata1
1Department of Chemical Science and Engineering, Graduate School of Engineering, Kobe University , 1-1 Rokkodai-cho, Nada-ku, Kobe 657-8501, Japan.
The Journal of Physical Chemistry. B
|August 29, 2015
Summary
The pH significantly impacts lactam-lactim tautomerism in specific compounds. Acidic conditions enhance tautomerism by increasing available protons, while alkaline conditions inhibit it due to deprotonation.
Area of Science:
- Inorganic Chemistry
- Physical Chemistry
- Spectroscopy
Background:
- Lactam-lactim tautomerism is a key chemical process influencing molecular properties.
- Understanding factors affecting tautomerism is crucial for designing new materials.
Purpose of the Study:
- To investigate the influence of molecular structure and pH on lactam-lactim tautomerism.
- To evaluate the tautomerism of specific inorganic compounds, cP3O6(NH)3(3-) and cP4O8(NH)4(4-).
Main Methods:
- Utilized (15)N NMR spectroscopy to analyze tautomerism.
- Examined the effects of varying solution pH (acidic and alkaline conditions).
Main Results:
- Tautomerism showed significant pH dependence, being inactivated in alkaline and activated in acidic conditions.
- cP3O6(NH)3(3-) exhibited higher tautomerism activity than cP4O8(NH)4(4-) due to its more planar structure and greater hydrogen delocalization.
- Identified critical factors for efficient anhydrous proton conductors.
Conclusions:
- Molecular planarity, number of dissociative protons, and low energy barriers for structural rearrangement are vital for efficient proton conduction.
- pH control is essential for modulating lactam-lactim tautomerism in these systems.
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