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In this paper, a known mixed-ligand MOF {[Co2(TZMB)2(1,4-bib)0.5(H2O)2]·(H2O)2}n (compound 1) was reproduced, and its potential application potential was explored. It was found that compound 1 had high photocatalytic activity for CO2 reduction. After 12 h of illumination, the formation rate of CO, which is the product of CO2 reduction by compound 1, reached 3012.5 μmol/g/h. At the same time, compound 1 has a good antibacterial effect on Staphylococcus aureus (S. aureus), Escherichia coli (E. coli) and Candida albicans (C. albicans), which has potential research value in the medical field. In addition, compound 1 can effectively remove Congo Red from aqueous solutions and achieve the separation of Congo red from mixed dye solutions.

Three mixed ligand complexes of copper(II) with adenine and dicarboxylic acids have been synthesized. The resulting complexes were characterized by their melting point, solubility, metal content analysis, FT-IR and UV-visible spectroscopy, magnetic measurement, thermal analysis, cyclic voltammetric measurement and X-ray powder diffraction study. The products are microcrystalline powder, slightly soluble in water and decompose at high temperature. Under experimental condition, the ligands adenine (Ade) behaves as a neutral ligand, whereas oxalic acid (OxH2), succinic acid (SucH2) and tartaric acid (TarH2) are doubly deprotonated to form dianionic ligands that are coordinated to the Cu(II) ion. The Cu(II) content analysis of the complexes confine to their stoichiometry [Cu(Ade)(L)(H2O)] (L = Ox, Suc, or Tar dianion). Electrochemical redox behavior of the complexes in their reaction medium was also examined. They exhibit quasi-reversible one-electron transfer processes. Dhaka Univ. J. Sci. 69(2): 76-81, 2021 (July)

There have been developed a novel synthetic method that allowed to obtain raw of mixed-ligand heterometallic binuclear complexes of Ge(IV)-M2+ (Mn, Fe, Co, Ni, Zn) with 1,3-diamino‑2-hydroxypropane N, N, N’, N’-tetraacetic acid (H5hpdta). Compounds have been characterized by the set of methods: elemental analysis, thermogravimetry, IR‑spectroscopy, spectrum of diffuse reflection, magnetic suspensibility. According to the elemental analysis, the molar ratio Ge: M: H5hpdta: bipy= 1:1:1:1 in the obtained compounds 1‑5 corresponds to the formula [(H2O)(OH)Ge(m-hpdta)M(bipy)]·nН2О (M=Mn n=3 (1), Fe n=2 (2), Co n=4 (3), Ni n=4 (4), Zn n=3 (5). Complexes have yellow (1), red (2), orange (3), violet (4) and pink (5) colors and are stable on air. Compounds 1‑5 exist in the form of crystal hydrates, that contain certain amount of water molecules, that are eliminated into the gas phase while heating in the wide range of temperatures (t=80‑250 °C), which is accompanied with the low-temperature endothermic effect. This indicates the presence of a system of stable hydrogen bonds in their crystal structure. Analysis of the IR‑spectra 1‑5 revealed that form and coordination of ligands is similar. Deprotonation of all carboxylic groups in the ligands (H5hpdta) and their bonding to germanium and d-metal is confirmed with the absence in the IR‑spectra 1‑5 absorption bands characteristic for the free СООН H5hpdta (1716 сm‑1) and nas(СОО-) і ns(СОО-) bands. Disappearance of the ν(С-OН)-1210 сm‑1 and appearance of the ν(С-O)alk., νas(Ge-O-M), νs(Ge-O- M) absorption band indicates that OH‑group of H5hpdta is deprotonated and performs bridging function. 2,2`-bipyridine bidentatly coordinates to the d-metal, binds to the O, N‑atoms of hpdta5- ligand and reaches coordination number 6. The last ligand plays the bringing role between Ge-dmetal, shows itself as ditopic, octadentate in total. According to the magnetic moments of 3, 4 and their diffuse reflection spectra, polyhedrons of Co (II), Ni (II) are octahedrons, which are realized due to the bidentate coordination of bipyridine and four bonds with nitrogen and oxygen of hpdta5-. Structure of heterometallic binuclear complexes 1‑5 is similar. Ligand hpdta5- shows itself as octadentate ditopic, all carboxylate groups monodentatly coordinate to metals, oxygen atom of the deprotonated OH‑group performs the bridging function.

Sulfamethoxazole and metronidazole are antibiotics use for the treatment of various bacterial infections. Their use as ligand is very prominent in formation of metal complexes. The transition metal complexes are synthesized by reaction of Sulfamethoxazole and metronidazole with metals such Mn(II), Cu(II), Fe(II) and Ni(II). The synthesized metal complexes are tested as antibacterial and antifungal. The antimicrobial activity of the complexes displays good potency against some microorganism such as Xanthomonas axonopodis, Streptococcus faecalia, Salmonella entrica, Claribacter michiganense, Xanthomonas phaseolin for bacteria and S.roofisii, M.phonoides, C.lindimuthianum for the fungi, it is revealed that all copper complexes show stronger antibacterial activity than the free drugs. The spectroscopic properties of the complexes were investigated using UV/visible and FT-IR which show metal-charge from 3d to 3s transition in which the transition state shows that they are octahedral geometry and their coordination site respectively. Their percentage yield was moderately high and producible. The complexes synthesized have higher inhibitory activities than the free ligand. The drug resistance in microbes is resulting in the incompetence of available drugs to care for the infections. The thermal analysis shows that the complexes are stable.

The effectiveness of the use of mixed ligand complexes of Zinc, Manganese and Cobalt in the diets of high-yielding cows in the final period of lactation, and their effect on productivity, nutrients digestibility and nitrogen metabolism in the animals’ body was studied in a scientific economic experiment conducted at the Terezyne Ltd. of Bila Tserkva district, Kyiv region. Five groups of highly productive cows of Holstein, Ukrainian red-spotted and Ukrainian black-spotted dairy breeds were selected on the principle of analogues. The difference in feeding cows of the groups was in the following: - the diet of the control 1st group was balanced to the norm only with trace elements of Selenium, Copper and Iodine. - cows of the 2nd and 3d experimental group were fed with the norm of all trace elements (for the 2nd experimental groupthe norm was provided due to introducing sulfates of Zinc, Manganese, Cobalt, Copper, Selenium Suplex and Potassium iodide; for the 3d experimental group , sulfates of Zinc, Manganese and Cobalt were substituted with their mixed ligand complexes). - for cows of 4th experimental group, the concentration of Zinc, Manganese and Cobalt in 1 kg of dry matter feed was reduced by 11% compared to the group 3. - for the 5thgroup it was 22% lower than in the group 3. The results of the studies show that the use different doses of mixed ligand complexes of Zinc, Manganese, Cobalt in cows feeding with the use of Selenium Suplex, Copper sulfate and Potassium iodide during the final 100 days of lactation did not affect milk productivity. Each cow of the control group in the final period of lactation yielded 2220 kg of natural milk, whereas the cows of the experimental groups 2-5 yielded 40-120 kg more. The difference in the average daily milk yield of 4% fat was 0.5–1.91 kg, and this difference was significant (p

No Abstract.

The results of establishing the optimal feeding doses of Zinc, Manganese, and Cobalt in the form of their mixed-ligand complexes for high-yielding cows of Holstein, Ukrainian Red-Spotted and Ukrainian Black-Spotted dairy breeds during the late dry period were presented, their influence on the future productivity and reproductive qualities of cows were also determined. It was found that lower doses of mixed-ligand complexes of Zinc, Manganese, and Cobalt in the feed mixture stimulated its consumption better. The cows of the 4th experimental group consumed more of the feed mixture, where the concentration of Zinc and Manganese was 35 mg, and Cobalt – 0.49 mg per 1 kg of DM. At various doses of mixed-ligand complexes of Zinc, Manganese, and Cobalt, the increase in live weight in cows of the control group was 24.3 kg, and in the experimental groups, it ranged from 23.7 kg to 26.9 kg, which is 8.6% and 10.7% (P < 0,05) more in the 3rd and 4th groups compared with the control. A decrease in the concentration of mixed-ligand complexes of Zinc, Manganese, and Cobalt in the diets of dry cows in the experimental groups by 10, 20, 30 and 40% had a positive effect on their further milk productivity. During the first 100 days of lactation, they milked 60-180 kg of milk more compared to the control with an increase in fat content by 0.01–0.05%. Also, in the milk of experimental group’s cows, compared with the control, the protein content increased (3.22–3.23% versus 3.14%), and the feed costs per 1 kg of milk in them were lower by 3.5–9.4%. Smaller doses of zinc, manganese, and cobalt contributed better to lengthening the period of prolonged action of their mixed-ligand complexes on the body of lactating cows. The calves’ live weight at the birth in the 4th experimental group exceeded the indicator of their peers from the control group by 2.3 kg or 8.81%, while the calves obtained from cows of the 2nd experimental group prevailed the control by 1.6 kg, or 6, 13 %, from the 3rd experimental group – by 1.8 kg, or 6.90%, and the 4th experimental group – by 1.7 kg, or 6.51%. The duration of the service period in all experimental groups of cows was within the recommended norms and was 87.8 days in the control group, and the 2nd, 3rd, 4th and 5th experimental groups, respectively 84.7 days, 82.2; 80.6 and 83.5 days, respectively, and there was less in control by 3.1–7.1 days or 3.3–8.2%. The insemination index in the cows’ control group was 1.5, and in the experimental one – 1.2–1.4, which is 6.7–20.0% less.

The article deals with the results of research to study the digestibility of nutrients in the ration and metabolism of Nitrogen, Zinc and Manganese in high-yielding Holstein cows of German selection in the first period of lactation for feeding mixed ligand complexes of Zinc, Manganese and Cobalt. The research was performed in the conditions of Terezyne Ltd., Bila Tserkva district, Kyiv region. There was an increase in the coefficients of digestibility of dry matter in cows of the 2nd-5th experimental groups compared with animals of the 1st control group, respectively by 1.8–3.5 % (P < 0.05); organic matter by 0.3–2.5 %; crude protein by 0.5–4.2 % (P < 0.05 – P < 0.01); crude fat by 1.1–1.8 %; crude fiber by 1.3–3.3 % and nitrogen-free extractives by 2.1–4.2 %. Cows of the experimental groups consumed more Nitrogen than the cows of the control group: 20.18 g or 2.4 % – the 2nd group, 55.06 g or 6.6 % – the 3rd, 42.52 g or 5, 1 % – 4th and 28.98 g or 3.5 % – 5th experimental group due to better eating of the feed mixture. General consumption level of Nitrogen in relation to excreted with milk and deposited in the body of cows of the control group was 32.02 %, and in animals of the 2nd, 3rd, 4th and 5th experimental groups – 33.59 %; 37.31; 36.99 and 34.97 %. In relation to the total digested amount, the proportion of Nitrogen deposited in the body and excreted with milk in animals of the control group was 42.38 %, and in the experimental – 44.25–47.34 %. Doses of Zinc, which provided its existing rate of 54–85 % due to the mixed ligand complex, positively influenced on the the metabolism of trace elements in the organism of experimental cows. Assimilation of Zinc in the organism was determined by the amount of its secretions with milk and deposits in the body and in absolute terms it was the lowest in cows of the 4th and 5th experimental groups – 562.7 mg and 671.6 mg against 740.8 mg in the 1st control group and the largest – 784.7 mg and 801.3 mg in animals of the 2nd and 3rd experimental groups. The use of a mixed ligand complex of manganese ensured its positive balance in the organism of cows and the absorption of the trace element in the organism of experimental cows ranged from 22.5 % in the 2nd experimental group to 33.2 % in the 3rd experimental group. The best indicators for the metabolism of Nitrogen, Zinc and Manganese were got in the third experimental group whose cows were fed a feed mixture, that in 1 kg of DM contained, mg: Zinc – 54.7; Manganese – 54.7; Cobalt – 0.7; Selenium – 0.3; Copper – 12 and Iodine – 1.1.

Treatment of [PdCl2(dppf)].CH2Cl2 or [PtCl2(dppf)] with two moles of 2-(benzylthio)-5-phenyl-1,3,4-oxadiazole (bpozs) in (ethanol: chloroform) solvents for (2 h) afford [M(bpozs)2(dppf)]Cl2 in good yield. The synthesized ligand and complexes were identified using FT-IR, 1H-NMR, 13C-NMR, 13P-NMR, CHNS analysis, Uv-Visible spectra and conductivity measurements. The physiochemical data indicated that the prepared complexes have square planar geometries and the metal ions coordinate with the ligands through two phosphorous atoms of (dppf) and nitrogen atom of (bpozs).

The metal complexes {Ni (II), Co (II) and Mn (II)} of 3-(2-(aryl)hydrazono)acetylacetone with isatin were synthesized and screened for their in vitro antibacterial activity against four pathogenic microorganisms {two Gram‐positive and two Gram negative}. The results of antibacterial activities revealed that all the metal complexes 1-9 exhibited moderate activities. Also, Lipinski's rule of five (RO5) of the mixed ligand metal complexes were calculated by SwissADME website. KEY WORDS: Isatin, 3-(2-(Aryl)hydrazono)acetylacetone, Metal complexes, Antibacterial activities, Lipinski rules Bull. Chem. Soc. Ethiop. 2020, 34(3), 533-541. DOI: https://dx.doi.org/10.4314/bcse.v34i3.9

In this current experiment, by applying the mixed-ligand synthesis method, two coordination polymers (CPs) containing Co(II) were created triumphantly with reaction between 1,3-bis(1-imidazoly)benzene (mbib) and Co(II) salts with the aid of diverse carboxylic ligands, and their chemical formulae are [Co3(opda)3(mbib)4(H2O)4]·2H2O (1, H2opda is 1,2-phenylenediacetic acid) and [Co(mpda)(mbib)]·H2O (2, H2mpda is 1,3-phenylenediacetic acid). The two compounds’ magnetic performances suggest that between the adjacent metal ions, there present the antiferromagnetic coupling. The evaluation of their treatment activity against chronic subdural hematoma was carried out and the relevant mechanism was studied simultaneously. Firstly, before the treatment of compound, the chronic subdural hematoma was generated. Furthermore, the enzyme-linked immunosorbent assay detection kit was implemented and in hematoma capsule, the anti-inflammatory cytokines level and pro-inflammatory cytokines level was detected. Additionally, the cytotoxicity of compounds 1 and 2 on the normal human cells was determined with Cell Counting Kit-8 assay. Above all, we proved compound 1 decreased the pro-inflammatory cytokines content and increased the anti-inflammatory cytokines content in the hematoma capsule, which is much stronger than that of compound 2. Both compounds 1 and 2 showed no cytotoxicity on the normal human cells.

Metformin is one of the most effective drugs for the treatment of type II diabetes. Two new mixed ligand complexes of vanadyl(ii) and chromium(iii) ions with the general formula [VOL1L2]SO4 and [CrL1L2(Cl)2]Cl, respectively, where L1 is the metformin and L2 is the glycine amino acid, have been synthesized in MeOH solvent with 1:1:1 stoichiometry and characterized by several spectroscopic techniques. The spectroscopic data suggested that the [VOL1L2]SO4 complex possesses a square pyramidal geometry, where the [CrL1L2(Cl)2]Cl complex possesses an octahedral geometry. The L1 ligand coordinated to the VO(ii) and Cr(iii) ions via the N atoms of the imino (‒C═NH) groups, where the L2 ligand coordinated via the O atom of the carboxylate group (COO) and the N atom of the amino group (NH2). The interaction of ligands L1 and L2 with the metal ions leads to complexes that have organized nanoscale structures with a main diameter of ∼14 nm for the [CrL1L2(Cl)2]Cl complex and ∼40 nm for the [VOL1L2]SO4 complex.

A series of mixed ligand complexes with a Schiff base (HL1) (obtained from 2-hydrazinobenzimidazole and ohydroxyacetophenone) acts as primary ligand and 1,10-phenanthroline (secondary ligand, L2) have been synthesized and investigated by various physico-analytical techniques. The spectral results suggested the tridentate nature of the Schiff base with NNO donor type. The prepared complexes exhibited distorted octahedral geometry. Moreover, molecular docking studies have been carried out against the SARS-CoV-2 spike receptor-binding domain (PDB ID: 6M0J) and SARS-CoV spike receptor-binding domain (PDB ID: 2AJF).

By utilizing the mixed-ligand method, two novel metal-organic frameworks (MOFs) based on Zn(II) ions as nodes with the chemical formulae of {[Zn2.5(abta)(trz)2(H2O)]·3H2O}n (1, Htrz = 1H-1,2,4-triazole) and [Zn3(abta)2(bibb)2]n (2, bibb = 1,4-bis(benzimidazol-1-yl)-2-butene) were produced via Zn(NO3)2·6H2O reacting with the 1-aminobenzene-3,4,5-tricarboxylic acid (H3abta) in the existence of distinct nitrogen-donor co-ligands. The different N-donor ligands result in their distinct framework structures, and the compound 1 with higher solvent accessible void and large window size shows highly heterogeneous catalytic activities for Knoevenagel condensation. The treatment of Staphylococcus aureus biofilms formation during spine surgery incision infection and the related mechanism was explored at the same time. First of all, the S. aureus bacterial numbers in the infectious site was measured under compound 1 or 2 treatment. In addition to this, the relative expression levels of the genes related with S. aureus biofilms was determined with real time RT-PCR.

The coordination compounds of propanedioic acid with cobalt(II), nickel(II) and copper(II) ions were synthesized using metal:ligand 1:2. In addition to this, mixed ligand complexes using the same metal ions with propanedioic acid as the primary ligand and N,N'-dihydroxy-2,3-butanediimine as the secondary ligand were also synthesized using M:L1:L2 (1:1:1) where L1 = propanedioic acid, L2 = N,N'-dihydroxy-2,3-butanediimine and M = Cu(II), Ni(II) and Cu(II). The synthesized compounds were characterized using FTIR, UV-vis, magnetic susceptibility measurement and percentage metal composition. The ligand and its metal complexes were tested for their cytotoxic and antibacterial activities. Results indicated that a dimeric square planar geometry was assumed by the cobalt(II) and nickel(II) propanedioic acid complexes. Octahedral geometry was proposed for both cobalt(II) and copper(II) mixed ligand complexes. A dinuclear square pyramidal geometry was suggested for the copper(II) propanedioic acid complex and square planar/octahedral geometry for the nickel(II) mixed ligand complex. The copper(II) propanedioic acid complex elicited the best cytotoxic activity. On the other hand, the nickel(II) propanedioic acid complex showed the remarkable antimicrobial activity. The compounds exhibited good antimicrobial activity in most of the cases with the exception of the cobalt(II) propanedioic acid complex. It was concluded that coordination of the ligands to the metal ions lowered the toxicity of the ligands. It was further concluded that the antimicrobial activity of the compounds was partly dependent on the synergism/additive effect of the intrinsic therapeutic properties of the metal ion and the ligands within the coordination sphere of the complexes synthesized. And this is also in part a function of the geometry assumed by the complexes.

Four mixed-ligand metal(II) complexes with the molecular formulae [M(ofl)(bipy)]NO3�H2O and [M(ofl)(phen)]NO3�H2O were synthesized by the reaction of Co(II) and Ni(II) with ofloxacin (Hofl) in the presence of 1,10-phenanthroline (phen) / 2,2`-bipyridine (bipy) (1:1:1 molar ratio). The data obtained from elemental analysis, molar conductance, spectral infrared, reflectance spectra and magnetic studies gave information about the coordination of the ligands and the geometry of the metallic ion. The results suggest that Hofl is deprotonated and bidentately bound to the metal ion through the pyridone oxygen and the carboxylato oxygen while phen and bipy act as neutral bidentate ligands coordinated through the nitrogen atoms. Tetrahedral geometry is proposed for all complexes. Thermal analysis data led to useful information concerning the composition, dehydration and thermal behaviour of the complexes. Ofloxacin and the metal complexes were tested for antibacterial activity and also for antioxidant activity. The variations of physicochemical parameters were monitored, which explain the antibacterial behaviour of these compounds. The interactions between metal complexes and bacterial receptors have lower energy values compared to the ofloxacin ligand. The molecular docking studies allow the identification of the biological target and the predictions of the bonds between the studied compounds and the receptors of E. coli (3t88), S. aureus (3q8u) and P. aeruginosa (4lkd).

Two novel mixed-ligand coordination polymers, {[Co(tdc)(btrp)]·0.67DMF}n (1) and {[Zn2(bimb)2(tdc)2]·2H2O}n (2) involving 2,5-thiophenedicarboxylate (H2tdc), and bitopic flexible N-donor ligands, 1,3-bis(1,2,4-triazol-1-yl)propane (btrp) and 1,4-bis((1H-benzo[d]imidazol-1-yl)methyl)benzene (bimb), have been synthesized by the hydrothermal method and characterized via IR, elemental analysis, thermal analysis, and powder X-ray diffraction. The biological functional studies were performed; the treatment activity of the compounds on periodontitis and the specific mechanism was explored. First, the real-time RT-PCR was carried out to determine the inflammatory genes nf-κb and p53 relative expression in periodontal mucosal cells after treating with compounds 1 and 2. Then, the level of the inflammatory cytokine in the gingival crevicular fluid after treating with compounds was also determined by the ELISA detection kit.

Hydroxypyridinone and hydroxypyranone are known to be used for the treatment of iron overload by chelation therapy for a long time. Both the ligands have their own side effects when used as medicines. In the present study homo and mixed ligand complexes of both the ligands with iron were prepared and characterized by UV-visible spectrophotometry, Potentiometric study, IR spectroscopy, SEM/EDX and XRD. Overlay spectra obtained from UV-visible spectroscopy of our studied system show the formation of different types of species and confirm that mixed ligand complex is different from the other two systems. Potentiometric titration curves of homo and mixed ligand complexes show the formation of different types of species at different pH and confirm the formation of mixed ligand complex. The comparative results of SEM images of these systems show different surface topologies and hence conform to the formation of mixed ligand complex.

Розроблені методики прямого спектрофотометричного визначення загального флуору у продуктах для гігієни порожнини рота з використанням змішанолігандного комплексу La(III) та алізарин-комплексону з флуоридйонами у присутності нейонної поверхнево-активної речовини. Встановлено, що у системі утворюється ряд комплексів різної стехіометрії та показано, що як аналітичну форму доцільно використовувати комплекс складу La:алізарин-комплексон:, який у присутності Tween 80 характеризується молярним коефіцієнтом поглинання ε620 = 11000 моль·дм-3 ·см -1. Показано, що калібрувальний графік є лінійним в діапазоні концентрацій флуорид-йонів 0,06–0,5 мкг/мл. Запропоновано просту, швидку та чутливу методику для спектрофотометричного визначення Fз використанням алізарин-комплексонату лантану в присутності Tween 80, яку було апробовано на зразках зубних паст та ополіскувачах ротової порожнини. A technique for direct spectrophotometric determination of total fluorine in products for oral hygiene using a mixed ligand complex La(III) and alizarincomplexone with fluoride ion in the presence of a non-ionic surfactant has been developed. A number of complexes of different stoichiometry formed in the system has been found. The La:alizarin-complexone:F= 1:2:1 complex was shown to be used as an analytical form. The complex in the presence of Tween 80 is characterized by the molar absorptivity ε620 = 11000 mol∙dm-3 ∙cm -1. The calibration curve is linear in the concentration range of fluoride ions 0.06–0.5 μg/ml. A simple, rapid, sensitive, and green procedure for the spectrophotometric determination of Fusing lanthanum alizarin-complexonate in the presence of Tween 80 was proposed and this technique was tested on samples of toothpastes and mouth rinses.

Синтезовано нові координаційні сполуки купруму(II) із заміщеними тіоамідами загальної формули [Сu(HL6-9)2X2]2 та CuL2 6-9. Досліджено реакції послідовного нуклеофільного заміщення/елімінування SN 1/E1 в октаедричному комплексі [Сu(NH3)4Cl2]∙H2O та каталітичного гідролізу комплексів [Сu(HL6-9)2X2]2. На основі даних елементного та рентгеноструктурного аналізу, ІЧ-спектроскопії встановлено склад і будову синтезованих комплексів. Молекулярну і кристалічну структуру комплексу [Cu(C30H26Cl2N6O8S2)]·iC3H7OН встановлено методом рентгеноструктурного аналізу. Досліджено триботехнічні характеристики (Іg, fтр) деяких координаційних сполук як додатків до індустріальних олив. New coordination compounds of copper(II) with substituted thioamides of the general formula [Cu(HL6-9)2X2]2 and CuL2 6-9 have been synthesized. The consecutive reaction of nucleophilic substitution/elimination of SN 1/E1 in the octahedral complex [Cu(NH3)4Cl2]·H2O and catalytic hydrolysis of [Cu(HL6-9)2X2]2 complexes have been investigated. Using IR spectroscopy, elemental and XRD analysis, the composition and structure of the synthesized complexes have been determined. The molecular and crystalline structure of the complex [Cu(C30H26Cl2N6O8S2)]·iC3H7ON was determined by X-ray diffraction analysis. The tribotechnical characteristics of some coordination compounds as additives to industrial oils have been investigated.

The Schiff base ligand L is developed from furan-2-carboxaldehyde, 4-aminoantipyrine together with 2-aminothiazole. The mixed ligand complexes are developed from the condensation of above Schiff base ligand L, 1,10-phenanthroline as well as metal(II) acetates of Co(II), Ni(II), Cu(II), and Zn(II). The newly produced compounds were characterized using molar conductance, elemental analysis, XRD, mass, UV-Vis, 1H NMR as well as IR spectral techniques. The X band ESR of [CuLphen] complex was recorded at 300 and 77 K. Geometry and Mulliken charge distribution of the L were studied using Density functional theory (DFT). In vitro biological analysis of L and its [CoLphen], [NiLphen], [CuLphen] as well as [ZnLphen] complexes were studied against bacterial variety such as Pseudomonas aeruginosa, Escherichia coli as well as Staphylococcus aureus. The fungal varieties include Aspergillus niger and Candida albicans. The potent DNA cleavage activities of L as well as its complexes were evaluated.

Mixed ligand complexes of copper(II) and nickel(II) with glycine (Gly) and histidine (His) have been studied in aqueous solution using calorimetric, potentiometric and spectrophotometric data at 298.15 K and the ionic strength of I = 0.5 mol·L–1 (KNO3). The thermodynamic parameters of formation of various mixed complexes have been determined. The probable coordination modes of amino acid residues in mixed ligand complexes is discussed.

New mixed ligand complexes of nickel(II) were synthesized by using dibasic H/5-bromo-/5-chloro-/4-hydroxy-2-hydroxybenzophenone-thiosemicarbazones (L1–4H2) and [Ni(PPh3)2Cl2]. The ligands and complexes were characterized by cyclic voltammetry, infrared, 1H and 31P NMR spectroscopy techniques. Crystallographic analyses of the 5-bromo-substituted (2) and 5-chloro-substituted (3) complexes as representatives were performed and so confirmed the ONS chelate structure and presence of PPh3 as co-ligand in the complexes. To reveal the antioxidant properties of the compounds, TEAC values (by CUPRAC method) were determined along with free radical-scavenging activity (by DPPH method). The compounds bearing 4-hydroxy substituent, L4H2 and complex 4 were the most effective compounds. The relationship between structure and antioxidant capacity in the context of benzophenone substituents and nickel(II) center was evaluated. Electrochemical results revealed that all complexes displayed metal-centered and ligand-centered redox processes. The antioxidant capacities of complexes were well correlated to electrochemical parameters.

Zirconium(II) and palladium(II) mixed ligand metal complexes were synthesized by using an equimolar mixture of tetracycline (Tc) as primary ligand and salicylaldehyde as secondary ligand. The metal complexes were characterized by physico-chemical and spectroscopic techniques like CHN analysis, surface tension, pH, conductivity and melting point measurements. The spectroscopic characterization technique includes IR, (1H & 13C) NMR, UV/visible and Mass spectrometry methods. The SEM technique determines the surface morphology of the complexes. The thermal and kinetic stability of the complexes was obtained from TGA/DTA curves from which the parameters like E*, ΔH*, ΔS* and ΔG* have been calculated by using the Coats-Redfern equation. Molecular modeling gives a geometry of the complex which was obtained from Chem 3D Pro. 12.0 software program. The metal complexes of Zr-TcSal and Pd-TcSal have coordinated with tetrahedral and square planar geometry, respectively. The antibacterial susceptibility study of the synthesized metal complexes was done by Kirby-Bauer paper disc diffusion techniques on S. aureus, E. coli and P. aeruginosa clinical pathogens

A new cationic mixed-ligand complex [Lа(L)2bipy2]BPh4 (where L-= bis(N,N'-diethylamide)(N'-trichloroacetyl)-triamidophosphate anion, bipy = 2,2'-bipyridine) has been synthesized and studied by the means of IR, 1H NMR spectroscopy, thermogravimetric and X-ray structural analyses. Low-frequency shifts of the absorption bands of the carbonyl and phosphoryl groups of phosphorylated ligand in the IR spectra of the complex compared with similar absorption bands in the spectrum of "free" CAPh ligand are Δν(C = O) = 117 cm–1 and Δν(P = O) = 137 cm–1. The analysis of integral signal intensity in the investigated NMR spectra of coordination compounds [Lа(L)2bipy2]BPh4 indicates the molar ratio of ligand : bipyridine : tetraphenylborate anion as a 2:2:1, which corresponds to the proposed structure of the complexes. The compound has been obtained in monocrystalline form. The structure of the complex has been determined by X-ray structural analysis, its ionic structure was proved, and the coordination of two CAPh ligands through the oxygen atoms of the carbonyl and phosphoryl groups was confirmed. Based on the structural data, it was determined that the La3+ ion is octocoordinated (surrounded by four oxygen atoms from two chelated phosphoryl ligands and four nitrogen atoms from two 2,2'-bipyridine molecules). The coordination polyhedron of central ion is interpreted as a square antiprism. Complex cations and tetraphenylborate anions are connected both by electrostatic interaction and by weak intermolecular C – H ∙∙∙ π-contacts between phenyl substituents of BPh4- and molecules of 2,2'-bipyridine. It was established by thermogravimetric analysis that the complex [Lа(L)2bipy2]BPh4 obtained is thermally stable up to a temperature of 150 °C. Significant decomposition of the complex begins at a temperature of 150 °C, occurs in one stage and most intensively continues up to 300 °C. The total weight loss is 78 %.

In this study, a short review covering the years 2009-2021 was made about the proton transfer salts obtained from the reaction of pyridine-acids, which are accepted as suitable proton donors, and piperazines, which are proton acceptors, and their metal complexes and mixed ligand metal complexes. In some complexes studied, both initial ion pairs bind to the metal, while in others they contain only one of the cationic and anionic moieties as ligands.

Five compounds 2-(2-Hydroxybenzylidene)-N-(prop-2-en1-yl)hydrazinecarbothioamide (H2L), bis[μ2-2-({2-[(prop-2-en-1-yl) carbamothioyl] hydrazinylidene}methyl) phenolatoS,N,O:O] diaquadicopper (II) nitrate (1), bis [μ2-2-({2-[(prop-2-en-1-yl) carbamothioyl] hydrazinylidene}methyl)phenolato-S,N,O:O]d iimidazoldicopper(II) nitrate (2), bis[μ2-2-({2-[(prop-2en-1-yl)carbamothioyl]-hydrazinylidene}methyl)phenolato-S,N,O:O]bis-(3,5-dibromopyridine)dicopper( II) nitrate hexahydrate (3), bis[μ2-2-({2-[(prop-2-en-1-yl)carbamothioyl]-hydrazinylidene}methyl) phenolato-S,N,O:O]bis(4-methylpyridine)dicopper(II) nitrate hexahydrate (4) were synthesized. The antiproliferative properties of these compounds towards cancer cell lines HeLa, RD and normal cell line MDCK have been investigated. The tested compounds demonstrated high antioxidant and antiproliferative, selective activities towards cancer cells. Direct toxic evaluation of compounds was performed by Daphnia magna bioassay.

Pd(TMPDA)Cl2 (TMPDA = N,N,N`,N`-tetramethyl-1,3-propanediamine) was synthesized and characterized by elemental analysis. [Pd(TMPDA)(H2O)2]2+ reacts with amino acid esters (L) to form mixed ligand [Pd(TMPDA)L]2+ complexes. The kinetics of base hydrolysis of [Pd(TMPDA)L]2+ was studied by pH-stat technique and the corresponding rate constants are reported. The coordinated glycine methyl ester is efficiently hydrolyzed, whereas the coordinated methionine methyl ester is hydrolysed with a much lower catalytic activity. The catalytic influence is depended on the mode of coordination of the ester to the palladium complex. Probable mechanisms for these reactions are considered. Activation parameters for the hydrolysis of the coordinated glycine methyl ester were determined experimentally. DFT calculations (B3LYP/LANL2DZ) were applied to determine the possible mechanism of the base hydrolysis of the amino acid esters. The calculations are discussed in reference to the reported experimental data.