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Hydrolysis of a Ni-Schiff-Base Complex Using Conditions Suitable for Retention of Acid-labile Protecting Groups
Published on: April 6, 2017
Two new structures in the glycine-oxalic acid system
Nikolay A Tumanov1, Elena V Boldyreva, Natalia E Shikina
1REC-008, Novosibirsk State University, Pirogova 2, Novosibirsk 630090, Russian Federation. n.tumanov@gmail.com
Summary
Two new glycine-oxalic acid salts were synthesized. Glycinium semi-oxalate-II exhibits unique cation-anion arrangements, suggesting solid-state transformation difficulty. Diglycinium oxalate methanol disolvate forms a 3D network via hydrogen bonds.
Area of Science:
- Crystal engineering and materials science.
- Supramolecular chemistry.
- Solid-state chemistry.
Background:
- Glycine-oxalic acid salts represent a significant class of compounds with diverse structural motifs.
- Understanding polymorphism and solvate formation is crucial for materials design and synthesis.
- Previous studies have established the structural characteristics of related compounds like glycinium semi-oxalate and diglycinium oxalate.
Purpose of the Study:
- To synthesize and characterize new crystalline forms within the glycine-oxalic acid family.
- To investigate the structural differences and potential solid-state transformations between polymorphs.
- To explore the formation and structural features of solvated salts and their relationship to crystallization conditions.
Main Methods:
- Single-crystal X-ray diffraction to determine the atomic arrangements and intermolecular interactions.
- Antisolvent crystallization techniques to control the formation of different salt forms and solvates.
- Comparative analysis of crystal structures to identify key differences in packing and bonding.
Main Results:
- The synthesis and structural elucidation of glycinium semi-oxalate-II (A), a new polymorph of glycinium semi-oxalate (C).
- Compound (A) displays distinct non-equivalent glycinium cations and semi-oxalate anions, with significantly different cation-cation binding compared to (C).
- Diglycinium oxalate methanol disolvate (B) was characterized, featuring a 3D hydrogen-bonded network formed by glycinium cations and oxalate anions, with embedded methanol molecules.
Conclusions:
- The structural differences between glycinium semi-oxalate polymorphs (A and C) suggest that solid-state transformation between them is likely to be challenging.
- The formation of diglycinium oxalate methanol disolvate (B) is influenced by crystallization kinetics, with slow antisolvent crystallization favoring the solvated form.
- This study expands the known structural diversity within the glycine-oxalic acid system and provides insights into crystal growth and polymorphism control.
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