Metal aminocarboxylate coordination polymers with chain and layered structures

Area of Science:

• Coordination Chemistry
• Materials Science
• Inorganic Chemistry

Background:

• Metal aminocarboxylates are versatile building blocks for coordination polymers.
• The synthesis conditions (acidic, neutral, alkaline) influence the resulting structures.
• Aminocarboxylic acids like glycine and 6-aminocaproic acid can form diverse coordination complexes.

Purpose of the Study:

• To synthesize and characterize metal aminocarboxylates.
• To explore the formation of coordination polymers with linear chain and two-dimensional layered structures.
• To investigate the influence of reaction media on the structural outcomes.

Main Methods:

• Hydro/solvothermal synthesis of metal salts with aminocarboxylic acids.
• Characterization of synthesized compounds using various analytical techniques (implied).
• Exploration of reactions under acidic, neutral, and alkaline conditions.

Main Results:

• One-dimensional chain structures of metal glycinates ([CoCl2(H2O)2(CO2CH2NH3)], [MnCl2(CO2CH2NH3)2], [Cd3Cl6(CO2CH2NH3)4]) were obtained in acidic media.
• 4-Aminobutyric acid transformed into a cyclic amide, forming a chain compound ([CdBr2(C4H7NO)2]).
• Two-dimensional layered compounds were synthesized using glycine ([Mn(H2O)2(CO2CH2NH3)2]Br2) and 6-aminocaproic acid ([Cd{CO2(CH2)5NH2}2]2 H2O, [Cu{CO2(CH2)5NH2}2]2 H2O), with the latter exhibiting voids.

Conclusions:

• The synthesis conditions significantly dictate the dimensionality and structure of metal aminocarboxylate coordination polymers.
• Glycine can form both linear chain and 2D layered structures depending on the reaction environment.
• 6-Aminocaproic acid under alkaline conditions yields 2D layered structures with potential applications in host-guest chemistry.