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09:04
A Direct, Early Stage Guanidinylation Protocol for the Synthesis of Complex Aminoguanidine-containing Natural Products
Published on: September 9, 2016
Theoretical studies on electron delocalization in diaminoguanidine
Prasad V Bharatam1, Pansy Iqbal
1Department of Medicinal Chemistry, National Institute of Pharmaceutical Education and Research (NIPER), S.A.S. Nagar (Mohali), 160 062 Punjab, India. pvbharatam@niper.ac.in
Journal of Computational Chemistry
|December 21, 2005
Summary
Diaminoguanidine (DAG) exhibits greater stability in its DAG1 isomer. Protonation enhances electron delocalization, with proton affinity exceeding that of guanidine and aminoguanidine due to intramolecular interactions.
Area of Science:
- Computational Chemistry
- Quantum Chemistry
- Molecular Modeling
Background:
- Diaminoguanidine (DAG) is a nitrogen-rich compound with potential applications.
- Understanding its electronic structure and stability is crucial for predicting its chemical behavior.
- Previous studies may not have fully explored its isomeric stability and protonation effects.
Purpose of the Study:
- To investigate the electronic structure and stability of diaminoguanidine isomers.
- To analyze electron delocalization patterns, including primary and secondary delocalizations.
- To determine the proton affinity of diaminoguanidine and compare it with related compounds.
Main Methods:
- Ab initio molecular orbital (MO) methods
- Density functional theory (DFT) calculations
- Natural Population Analysis (NPA) for electron delocalization
Main Results:
- The DAG1 isomer of diaminoguanidine demonstrates superior stability compared to DAG2 and DAG3.
- Natural Population Analysis reveals significant primary and secondary electron delocalizations within DAG.
- Protonated diaminoguanidine exhibits enhanced stability due to intramolecular interactions, leading to a higher proton affinity than guanidine and aminoguanidine.
Conclusions:
- The DAG1 isomer is the most stable form of diaminoguanidine.
- Intramolecular interactions in protonated DAG significantly increase its proton affinity.
- Electron delocalization increases upon protonation, similar to guanidine and aminoguanidine, indicating conserved electronic response mechanisms.
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