SYNTHESIS AND BIOLOGICAL ACTIVITY OF 3d-­METAL COMPLEXES WITH BIS(PHOSPHONOMETHYL)AMINOSUNRIC ACID

Abstract

New complexes of 3d-metals (Co2+, Ni2+, Zn2+) with bis(phosphonomethyl)aminosuccinic acid (H6BPMAS) have been synthesized. The complexes were studied in aqueous solutions at ratios M2+:H6BPMAS = 1:1 in a wide pH range (1÷10). Regardless of the nature of the metal, the formation of complexes of the general composition [M(HnBPMAS)(OH)m] (n= 4÷0, m=1÷0) is shown. The stability constants of the formed differently protonated complexes are calculated and diagrams of their distribution are plotted. It is shown that the process of complexation takes place most completely in the region of pH>4. For all bis(phosphonomethyl)aminosuccinates of 3d metals, the dominance of the complex with one form of the ligand occurs in approximately the same pH ranges. A close order of change in the values of lgKst. complexes testifies to the same type of structure of their internal coordination sphere.
 Solid complexes of the composition Na4[MBPMAS]⋅4H2O were synthesized. Their composition, structure, and thermal characteristics were determined by the set of me­thods such as diffuse reflectance spectroscopy, IR spectroscopy, DTA and non-quantitative mass spectrometry. It is proved that the complexes have the structure of a distorted octahedron, in which the 3-d metal ions are bound to the oxygen atoms of the carboxyl and phosphonic groups and the tertiary nitrogen atom of the ligand. At the same time, two 5-membered (aminomethylenephosphonic and glycine) and one 6-membered (β-alanine) metallocycles are formed in bis(phosphonomethyl)aminosuccinates.
 The biological activity of H6BPMAS and its complexes with Ni(II) and Co(II) against non-pathogenic bacterial species of microorganisms Pseudomonas fluorescens and Pseudomonas aureofaciens was studied. The study of the activity of substances was carried out in a liquid sterile Hiss medium. The maxi­mum stimulating effect on the growth of bacterial cultures for the studied compounds was recorded at a concentration of 1 µM in 24 hours after the start of cultivation of mic­ro­organisms. The highest growth of microorganisms was recorded for metal complexes (50% Na4[CoBPMAS]·4H2O and 35% Na4[NiBPMAS]·4H2O). The maximum stimulating effect on the growth of bacterial cultures is shown by the Co(II) complex, which is able to initiate the synthesis of one of the most important growth hormones - heteroauxin.

LUMINESCENT PROPERTIES OF Nd(III) COMPLEXES WITH ETHY­LENE­DIAMINE-N,N'-DISUCCINIC AND N,N-BIS(PHOSPHONO­METHYL)-2-AMINOPROPIONIC ACIDS

“…; τ fl = 12.3 and 4.8 ns) two methyleneaminodiacetate fragments, which make up 50% of the mass of the molecule, rotate freely, causing a non-radiative loss of excitation energy, which explains the weak fluorescence of this form of the ligand. It should be noted that, despite the significant advantage of the presence of the (H 2 L) 2form in the solution, the value of the second τ fl =4.8 ns indicates the presence of other protoned forms of EDDS in this pH region [35]. At pH>8 (Fig.…”

СOMPLEXES OF Nd(III) AND 3d-METALS BASED ON ETHYLENEDIAMINEDISUCCINIC ACID AS POTENTIAL ANTIFUNGAL AGENTS

“…Homonuclear complexes of 3-d metals obtained by the interaction of aqueous solutions of EDDS and d-metal salts in an acidic medium were used as a «building block». Нeterometallic complexes were obtained without separating the «building block» from the solution [26,27].…”

“…The synthesized NdM II EDDS heterometallic complexes were isolated from solutions using the isothermal method (salting out with ethanol from aqueous solutions) at pH 7.5, which corresponds to the maximum accumulation of deprotonated complexes according to the distribution diagrams [26,27]. Identification and purity of НМС was established by elemental analysis and IR spectroscopy.…”

Modeling the effects of essential heavy metals on environmental pollution: A linear and nonlinear prediction model via cascade forward‐neural network

“…Cu is taken to the plant in the form of 2+ valence cations and copper chelates. It plays an effective role in the activation of oxidase group enzymes, in the structure of some proteins, and also in carbohydrate metabolism in plants [22,23]. In case of lack of copper, which is also involved in photosynthesis reactions, poor growth in the plant, chlorosis, and wilting of the leaves can be observed.…”