Preparation, Characterization, Thermal Degradation, and Crystal Structures of Hydrazinium and Ammonium Salts of Ethylenediaminetetraacetic Acid and Seven Coordinated N₂H₅[Cd(Hedta)(H₂O)].H₂O

Abstract

Dihydrazinium, hydrazinium, hydrazinium ammonium, and ammonium salts of ethylenediaminetetraacetic acid (H₄edta) such as (N₂H₅)₂H₂edta, N₂H₆H₂edta, N₂H₅NH₄H₂edta and (NH₄)₂H₂edta have been prepared and characterized by elemental analyses, hydrazine analysis, conductivity measurements, and infrared spectra. The thermal degradation studies reveal that these compounds undergo complete and multi step decomposition with or without melting. The IR spectra show that in all the cases the acidic protons are attached to the tertiary nitrogen atoms of edta and all the salts exist as zwitterions. The X-ray single-crystal data and the corresponding ORTEP diagram of the dihydrazinium and hydrazonium salts clearly support and confirm the data. Hydrazinium hydrogenethylenediaminetetraacetato aquo cadmium(II) monohydrate, N₂H₅[Cd(Hedta)(H₂O)].H₂O, has been synthesized and structurally characterized. The crystal belongs to orthorhombic crystal system and the space group Pbca. The crystal data are the following: a = 9.423 Å, b = 4.406 Å, c = 23.838 Å, α = β = γ = 90°, V = 3236 ų, Z = 8, D_c = 1.932 Mg/m³_, μ = 1.412 mm⁻¹, F(000) = 1904, the final R = 0.0190, and wR = 0.0562 for 3707 observed reflection with I›2σ(I).

Keywords:

• hydrazinium
• hydrazonium
• ammonium
• ethylenediaminetetraacetic acid
• X-ray single crystal

Acknowledgement

The authors sincerely thank, Maduari Kamraj University, Mudurai, and IIT – Madras, Chennai, for recording X-ray diffraction data.

Funding

The authors also thank UGC-New Delhi for financial assistance in the form of minor research project.