Structure and fertilizer properties of byproducts formed in the synthesis of EDDHA.
The synthesis of commercial EDDHA produces o,o-EDDHA as the main reaction product, together with a mixture of regioisomers (o,p-EDDHA and p,p-EDDHA) and other unknown byproducts also able to complex Fe3+. These compounds have been obtained by direct synthesis, and their structures have been determined by ESI-MS analysis as oligomeric EDDHA-like products, formed by polysubstitution in the phenolic rings. Short-term experiments show that the iron complexes of samples enriched in these oligomeric byproducts have adequate stability in solution, but a significant amount of them is lost after interaction with soils and soil materials. Mildly chlorotic cucumber plants are able to reduce iron better from o,p-EDDHA/Fe3+ than from the iron complexes of the oligomeric byproducts. In hydroponics, the chlorotic soybean susceptible plants have a lower potential for Fe absorption from these byproducts than from o,o-EDDHA/Fe3+ and from o,p-EDDHA/Fe3+. In the studied conditions, the iron chelates of EDDHA byproducts do not have the long-lasting effect shown by o,o-EDDHA/Fe3+ and present a less efficient fast-action effect than the o,p-EDDHA/Fe3+.
Hernández-Apaolaza
Lourdes
L
Departamento de Química Agrícola, Facultad de Ciencias, CVII, Universidad Autónoma, 28049 Madrid, Spain.
García-Marco
Sonia
S
Nadal
Paloma
P
Lucena
Juan J
JJ
Sierra
Miguel A
MA
Gómez-Gallego
Mar
M
Ramírez-López
Pedro
P
Escudero
Rosa
R
D016573:Agrochemicals; D018553:Cucumis sativus / Q000378:metabolism; D004355:Drug Stability; D005029:Ethylenediamines / Q000138:chemical synthesis* / Q000737:chemistry*; D005308:Fertilizers; D007501:Iron / Q000737:chemistry / Q000378:metabolism; D007536:Isomerism; D009682:Magnetic Resonance Spectroscopy; D015394:Molecular Structure; D010944:Plants / Q000378:metabolism; D012987:Soil / Q000032:analysis; D012996:Solutions; D013025:Glycine max / Q000378:metabolism; D021241:Spectrometry, Mass, Electrospray Ionization
D016573:Agrochemicals; D005029:Ethylenediamines; D005308:Fertilizers; D012987:Soil; D012996:Solutions; C011813:ethylenediamine-N,N'-bis(2-hydroxyphenylacetic acid); D007501:Iron