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A special issue of Molecules (ISSN 1420-3049). This special issue belongs to the section "Cross-Field Chemistry".

Deadline for manuscript submissions: closed (30 April 2023) | Viewed by 20277

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Dr. Mostafa A. Hussien

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Department of Chemistry, Faculty of Science, King Abdulaziz University, Jeddah P.O. Box 80203, Saudi Arabia
Interests: coordination chemistry; metal–drug complexes; organometallic chemistry; DNA binding; molecular docking; theoretical calculation; biological activity

Special Issue Information

Dear Colleagues,

In this Special Issue, we strive to demonstrate the numerous crucial breakthroughs in metal complexes, concentrating on their properties and wide range of applications to tackle the challenges in human health/disease and the environment. Several topics will be presented and discussed under the scope of this Special Issue, mainly focused on the chemistry and applications of metal complexes, notably solution equilibria and coordination chemistry, metal complexes of biological and environmental interest, supramolecular chemistry, metal–complex interactions with biomolecules, nanostructured metal complexes, metals in diseases (transport, homeostasis, and toxicity), metal-based drugs (therapy and diagnosis), metalloenzymes (metal binding and models), analytical methods and sensors based on metal complexes, and computational modeling.

Dr. Mostafa A. Hussien
Guest Editor

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Keywords

metal complexes
coordination compounds
biological application
catalytic properties
optical properties
biosensors and chemosensors
nanoparticles
environmental application

Published Papers (12 papers)

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Research

18 pages, 5613 KiB

Open AccessArticle

Mechanisms of Sulfoxidation and Epoxidation Mediated by Iron(III)-Iodosylbenzene Adduct: Electron-Transfer vs. Oxygen-Transfer Mechanism

by Patrik Török, Dóra Lakk-Bogáth and József Kaizer

Molecules 2023, 28(12), 4745; https://doi.org/10.3390/molecules28124745 - 13 Jun 2023

Cited by 1 | Viewed by 955

Abstract

The mechanisms of sulfoxidation and epoxidation mediated by previously synthesized and characterized iron(III)-iodosylbenzene adduct, Fe^III(OIPh) were investigated using para-substituted thioanisole and styrene derivatives as model substrates. Based on detailed kinetic reaction experiments, including the linear free-energy relationships between the relative reaction rates (logk_rel) and the σ_p (4R-PhSMe) with ρ = −0.65 (catalytic) and ρ = −1.13 (stoichiometric), we obtained strong evidence that the stoichiometric and catalytic oxidation of thioanisoles mediated by Fe^III(OIPh) species involves direct oxygen transfer. The small negative slope −2.18 from log k_obs versus E_ox for 4R-PhSMe gives further clear evidence for the direct oxygen atom transfer mechanism. On the contrary, with the linear free-energy relationships between the relative reaction rates (logk_rel) and total substituent effect (TE, 4R-PhCHCH₂) parameters with slope = 0.33 (catalytic) and 2.02 (stoichiometric), the stoichiometric and catalytic epoxidation of styrenes takes place through a nonconcerted electron transfer (ET) mechanism, including the formation of the radicaloid benzylic radical intermediate in the rate-determining step. On the basis of mechanistic studies, we came to the conclusion that the title iron(III)-iodosylbenzene complex is able to oxygenate sulfides and alkenes before it is transformed into the oxo-iron form by cleavage of the O−I bond. Full article

(This article belongs to the Special Issue Applications of Metal Complexes)

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23 pages, 2775 KiB

Open AccessArticle

Structural and Spectroscopic Study of New Copper(II) and Zinc(II) Complexes of Coumarin Oxyacetate Ligands and Determination of Their Antimicrobial Activity

by Muhammad Mujahid, Natasha Trendafilova, Georgina Rosair, Kevin Kavanagh, Maureen Walsh, Bernadette S. Creaven and Ivelina Georgieva

Molecules 2023, 28(11), 4560; https://doi.org/10.3390/molecules28114560 - 05 Jun 2023

Cited by 4 | Viewed by 1610

Abstract

Tackling antimicrobial resistance is of increasing concern in a post-pandemic world where overuse of antibiotics has increased the threat of another pandemic caused by antimicrobial-resistant pathogens. Derivatives of coumarins, a naturally occurring bioactive compound, and its metal complexes have proven therapeutic potential as antimicrobial agents and in this study a series of copper(II) and zinc(II) complexes of coumarin oxyacetate ligands were synthesised and characterised by spectroscopic techniques (IR, ¹H, ¹³C NMR, UV-Vis) and by X-ray crystallography for two of the zinc complexes. The experimental spectroscopic data were then interpreted on the basis of molecular structure modelling and subsequent spectra simulation using the density functional theory method to identify the coordination mode in solution for the metal ions in the complexes. Interestingly, the solid-state coordination environment of the zinc complexes is in good agreement with the simulated solution state, which has not been the case in our previous studies of these ligands when coordinated to silver(I). Previous studies had indicated excellent antimicrobial activity for Ag(I) analogues of these ligands and related copper and zinc complexes of coumarin-derived ligands, but in this study none of the complexes displayed antimicrobial activity against the clinically relevant methicillin-resistant Staphylococcus aureus (MRSA), Pseudomonas aeruginosa and Candida albicans. Full article

(This article belongs to the Special Issue Applications of Metal Complexes)

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15 pages, 3985 KiB

Open AccessArticle

Highly Luminescent Europium(III) Complexes in Solution and PMMA-Doped Films for Bright Red Electroluminescent Devices

by Zubair Ahmed, Rafael dos Santos Carvalho, Aline Magalhães dos Santos, Francesca Gambassi, Elisa Bandini, Lorenza Marvelli, Lucia Maini, Andrea Barbieri and Marco Cremona

Molecules 2023, 28(11), 4371; https://doi.org/10.3390/molecules28114371 - 26 May 2023

Cited by 2 | Viewed by 1493

Abstract

This paper reports the synthesis, structure, photophysical, and optoelectronic properties of five eight-coordinate Europium(III) ternary complexes, namely, [Eu(hth)₃(L)₂], bearing 4,4,5,5,6,6,6-heptafluoro-1-(2-thienyl)-1,3-hexanedione (hth) as a sensitizer and L = H₂O (1), dpso (diphenyl sulphoxide, 2), dpsoCH₃ (4,4′-dimethyl diphenyl sulfoxide, 3), dpsoCl (bis(4-chlorophenyl)sulphoxide, 4), and tppo (triphenylphosphine oxide, 5) as co-ligands. The NMR and the crystal structure analysis confirmed the eight-coordinate structures of the complexes in solution and in a solid state. Upon UV-excitation on the absorption band of the β-diketonate ligand hth, all complexes showed the characteristic bright red luminescence of the Europium ion. The tppo derivative (5) displayed the highest quantum yield (up to 66%). As a result, an organic light-emitting device, OLED, was fabricated with a multi-layered structure—ITO/MoO₃/mCP/SF3PO:[complex 5] (10%)/TPBi:[complex 5] (10%)/TmPyPB/LiF/Al—using complex 5 as the emitting component. Full article

(This article belongs to the Special Issue Applications of Metal Complexes)

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19 pages, 1898 KiB

Open AccessArticle

Synthesis, Structure and Biological Activity of Indole–Imidazole Complexes with ZnCl₂: Can Coordination Enhance the Functionality of Bioactive Ligands?

by Karolina Babijczuk, Beata Warżajtis, Justyna Starzyk, Lucyna Mrówczyńska, Beata Jasiewicz and Urszula Rychlewska

Molecules 2023, 28(10), 4132; https://doi.org/10.3390/molecules28104132 - 16 May 2023

Cited by 3 | Viewed by 1578

Abstract

The ability of the indole–imidazole hybrid ligands to coordinate with the Zn(II) ion and the resulting structures of this new class of coordination compounds were analyzed in order to determine their structural properties and biological functionalities. For this purpose, six novel Zn(II) complexes, [Zn(InIm)₂Cl₂] (1), [Zn(InMeIm)₂Cl₂] (2), [Zn(IniPrIm)₂Cl₂] (3), [Zn(InEtMeIm)₂Cl₂] (4), [Zn(InPhIm)₂Cl₂] (5) and [Zn₂(InBzIm)₂Cl₂] (6) (where InIm is 3-((1H-imidazol-1-yl)methyl)-1H-indole), were synthesized by the reactions of ZnCl₂ and the corresponding ligand in a 1:2 molar ratio in methanol solvent at an ambient temperature. The structural and spectral characterization of these complexes was performed using NMR, FT–IR and ESI–MS spectrometry and elemental analysis, and the crystal structures of 1–5 were determined using single-crystal X-ray diffraction. Complexes 1–5 form polar supramolecular aggregates by utilizing, for this purpose, the N-H(indole)∙∙∙Cl(chloride) intermolecular hydrogen bonds. The assemblies thus formed differ depending on the distinctive molecular shape, which can be either compact or extended. All complexes were screened for their hemolytic, cytoprotective, antifungal, and antibacterial activities. The results show that the cytoprotective activity of the indole/imidazole ligand significantly increases upon its complexation with ZnCl₂ up to a value comparable with the standard antioxidant Trolox, while the response of its substituted analogues is diverse and less pronounced. Full article

(This article belongs to the Special Issue Applications of Metal Complexes)

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13 pages, 4450 KiB

Open AccessArticle

Silver(I) Coordination Polymer Ligated by Bipyrazole Me₄bpzH₂, [Ag(X)(Me₄bpzH₂)] (X = CF₃CO₂⁻ and CF₃SO₃⁻, Me₄bpzH₂ = 3,3′,5,5′-Tetramethyl-4,4′-bipyrazole): Anion Dependent Structures and Photoluminescence Properties

by Kiyoshi Fujisawa, Yui Kobayashi, Mitsuki Okano, Ryota Iwabuchi, Shiori Kondo and David James Young

Molecules 2023, 28(7), 2936; https://doi.org/10.3390/molecules28072936 - 24 Mar 2023

Viewed by 1274

Abstract

Coordination polymers of transition metal ions are fascinating and important to coordination chemistry. One of the ligands known to form particularly interesting coordination polymers is 3,3′,5,5′-tetramethyl-4,4′-bipyrazole (Me₄bpzH₂). Group 11 metal(I) ion coordination polymers, other than those of copper(I), are relatively easy to handle because of their low reactivity towards dioxygen and moisture. However, the known silver(I) coordination polymers often have poor solubility in common solvents and so cannot be easily analyzed in solution. By using a tetramethyl substituted bipyrazole ligand, we have synthesized more soluble silver(I) complexes that contain the trifluoromethyl group in the coordinated ions CF₃CO₂⁻ and CF₃SO₃⁻ in [Ag(CF₃CO₂)(Me₄bpzH₂)] and [Ag(CF₃SO₃)(Me₄bpzH₂)]. We determined both structures by single-crystal X-ray analysis at low temperatures and compared them in detail. Moreover, we investigated the solution behavior of these coordination polymers by ¹H-NMR, IR, Raman, UV–Vis spectroscopies, and their low-temperature, solid-state photoluminescence. The high-energy band at ~330 nm corresponded to ligand-centered (bipyrazole) fluorescence, and the low-energy band at ~400 nm to ligand-centered phosphorescence resulting from the heavy atom effect. Full article

(This article belongs to the Special Issue Applications of Metal Complexes)

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14 pages, 3518 KiB

Open AccessArticle

Structure and Properties of Heterometallics Based on Lanthanides and Transition Metals with Methoxy-β-Diketonates

by Vladislav V. Krisyuk, Samara Urkasym Kyzy, Tatyana V. Rybalova, Ilya V. Korolkov, Mariya A. Grebenkina and Alexander N. Lavrov

Molecules 2022, 27(23), 8400; https://doi.org/10.3390/molecules27238400 - 01 Dec 2022

Cited by 3 | Viewed by 1167

Abstract

The possibility of obtaining volatile polynuclear heterometallic complexes containing lanthanides and transition metals bound by methoxy-β-diketonates was studied. New compounds were prepared by cocrystallization of monometallic complexes from organic solvents. Ln(tmhd)₃ were used as initial monometallic complexes (Ln = La, Pr, Sm, Gd, Tb, Dy, Lu; tmhd = 2,2,6,6-tetramethylheptane-3,5-dionate) in combination with TML₂ in various ratios (TM = Cu, Co, Ni, Mn; L: L¹ = 1,1,1-trifluoro-5,5-dimethoxypentane-2,4-dionate, L² = 1,1,1-trifluoro-5,5-dimethoxy-hexane-2,4-dionate, L³ = 1,1,1-trifluoro-5-methoxy-5-methylhexane-2,4-dionate). Heterometallic complexes of the composition [(LnL₂tmhd)₂TM(tmhd)₂] were isolated for light lanthanides Ln= La, Pr, Sm, Gd, and L= L¹ or L². By single crystal XRD, it has been established that heterometallic compounds containing La, Pr, Cu, Co, and Ni are isostructural linear coordination polymers of alternating mononuclear transition metal complexes and binuclear heteroleptic lanthanide complexes, connected by donor–acceptor interactions between oxygen atoms of the methoxy groups and transition metal atoms. A comparison of powder XRD patterns has shown that all heterometallic complexes obtained are isostructural. Havier lanthanides Ln = Tb, Dy, Lu did not form heterometallics. Instead, homometallic complexes Ln(L³)₃ were identified for Ln = Dy, Lu as well as for Ln = La. The thermal properties of the complexes were investigated by TG-DTA and vacuum sublimation tests. The heterometallic complexes were found to be not volatile and decomposed under heating to produce inorganic composites of TM oxides and Ln fluorides. In contrast, Ln(L³)₃ is volatile and may be sublimed in a vacuum. Results of magnetic measurements are discussed for several heterometallic and homometallic complexes. Full article

(This article belongs to the Special Issue Applications of Metal Complexes)

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24 pages, 3507 KiB

Open AccessArticle

Charge Transfer Chromophores Derived from 3d-Row Transition Metal Complexes

by Kira I. Pashanova, Irina V. Ershova, Olesya Yu. Trofimova, Roman V. Rumyantsev, Georgy K. Fukin, Artem S. Bogomyakov, Maxim V. Arsenyev and Alexandr V. Piskunov

Molecules 2022, 27(23), 8175; https://doi.org/10.3390/molecules27238175 - 24 Nov 2022

Cited by 10 | Viewed by 1693

Abstract

A series of new charge transfer (CT) chromophores of “α-diimine-M^II-catecholate” type (where M is 3d-row transition metals—Cu, Ni, Co) were derived from 4,4′-di-tert-butyl-2,2′-bipyridyl and 3,6-di-tert-butyl-o-benzoquinone (3,6-DTBQ) in accordance with three modified synthetic approaches, which provide high yields of products. A square-planar molecular structure is inherent for monomeric [Cu^II(3,6-Cat)(bipy^t^Bu)]∙THF (1) and Ni^II(3,6-Cat)(bipy^t^Bu) (2) chromophores, while dimeric complex [Co^II(3,6-Cat)(bipy^t^Bu)]₂∙toluene (3) units two substantially distorted heteroleptic D-M^II-A (where D, M, A are donor, metal and acceptor, respectively) parts through a donation of oxygen atoms from catecholate dianions. Chromophores 1–3 undergo an effective photoinduced intramolecular charge transfer (λ = 500–715 nm, extinction coefficient up to 10⁴ M⁻¹·cm⁻¹) with a concomitant generation of a less polar excited species, the energy of which is a finely sensitive towards solvent polarity, ensuring a pronounced negative solvatochromic effect. Special attention was paid to energetic characteristics for CT and interacting HOMO/LUMO orbitals that were explored by a synergy of UV-vis-NIR spectroscopy, cyclic voltammetry, and DFT study. The current work sheds light on the dependence of CT peculiarities on the nature of metal centers from various groups of the periodic law. Moreover, the “α-diimine-M^II-catecholate” CT chromophores on the base of “late” transition elements with differences in d-level’s electronic structure were compared for the first time. Full article

(This article belongs to the Special Issue Applications of Metal Complexes)

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11 pages, 1407 KiB

Open AccessArticle

Iron Porphyrin as a Cytochrome P450 Model for the Degradation of Dye

by Dan-Dan Ren, Xiaoyan Lu, Li-Ping Zhou, Huanghongjun Tian, Shuang Wang, Lu-Fang Ma and Dong-Sheng Li

Molecules 2022, 27(22), 7948; https://doi.org/10.3390/molecules27227948 - 17 Nov 2022

Cited by 2 | Viewed by 1632

Abstract

Organic dyes are widely used in the textile, biological, medical and other fields. However, a serious environmental problem has appeared because of the presence of organic dyes in industrial aqueous effluents. Thus, the efficient treatment of organic dyes in industrial wastewaters is currently in real demand. The current study investigated the oxidative degradation of the organic dye gentian violet by meso-tetra(carboxyphenyl) porphyriniron(III), [Fe^III(TCPP)] as a cytochrome P450 model and iodosylbenzene (PhIO) as an oxidant at room temperature. The degradation reaction was monitored by UV–vis absorption spectroscopy via the observation of UV–vis spectral changes of the gentian violet. The results showed that the efficiency of catalyzed degradation reached more than 90% in 1 h, indicating the remarkable oxidative degradation capacity of the [Fe^III(TCPP)]/PhIO system, which provided an efficient approach for the treatment of dyeing wastewater. Full article

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29 pages, 6631 KiB

Open AccessArticle

A Novel Ibuprofen Derivative and Its Complexes: Physicochemical Characterization, DFT Modeling, Docking, In Vitro Anti-Inflammatory Studies, and DNA Interaction

by Abbas M. Abbas, Ahmed Aboelmagd, Safaa M. Kishk, Hossam H. Nasrallah, Warren Christopher Boyd, Haitham Kalil and Adel S. Orabi

Molecules 2022, 27(21), 7540; https://doi.org/10.3390/molecules27217540 - 03 Nov 2022

Cited by 6 | Viewed by 2575

Abstract

A novel derivative of ibuprofen and salicylaldehyde N′-(4-hydroxybenzylidene)-2-(4-isobutylphenyl) propane hydrazide (HL) was synthesized, followed by its complexation with Cu, Ni, Co, Gd, and Sm. The compounds obtained were characterized by ¹HNMR, mass spectrometry, UV-Vis spectroscopy, FT-IR spectroscopy, thermal analysis (DTA and TGA), conductivity measurements, and magnetic susceptibility measurements. The results indicate that the complexes formed were [Cu(L)(H₂O)]Cl·2H₂O, [Ni(L)₂], [Co(L)₂]·H₂O, [Gd(L)₂(H₂O)₂](NO₃)·2H₂O and [Sm(L)₂(H₂O)₂](NO₃)·2H₂O. The surface characteristics of the produced compounds were evaluated by DFT calculations using the MOE environment. The docking was performed against the COX2 targeting protein (PDB code: 5IKT Homo sapiens). The binding energies were −7.52, −9.41, −9.51, −8.09, −10.04, and −8.05 kcal/mol for HL and the Co, Ni, Cu, Sm, and Gd complexes, respectively, which suggests the enhancement of anti-inflammatory behaviors compared with the binding energy of ibuprofen (−5.38 kcal/mol). The anti-inflammatory properties of the new compounds were assessed in vitro using the western blot analysis method and the enzyme-linked immunosorbent assay (ELISA), consistent with the outcomes obtained from docking. The half-maximal inhibitory concentration (IC₅₀) values are 4.9, 1.7, 3.7, 5.6, 2.9, and 2.3 µM for HL and the Co, Ni, Cu, Sm, and Gd complexes, respectively, showing that they are more effective inhibitors of COX2 than ibuprofen (IC₅₀ = 31.4 µM). The brain or intestinal estimated permeation method (BOILED-Egg) showed that HL and its Co complex have high gastrointestinal absorption, while only the free ligand has high brain penetration. The binding constants of Co, Cu, and Gd complexes with DNA were recorded as 2.20 × 10⁴, 2.27 × 10^6, and 4.46 × 10³ M⁻¹, respectively, indicating the intercalator behavior of interaction. The newly synthesized ibuprofen derivative and its metal complexes showed greater anti-inflammatory activity than ibuprofen. Full article

(This article belongs to the Special Issue Applications of Metal Complexes)

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20 pages, 5431 KiB

Open AccessArticle

Synthesis, Structure and Cytotoxic Properties of Copper(II) Complexes of 2-Iminocoumarins Bearing a 1,3,5-Triazine or Benzoxazole/Benzothiazole Moiety

by Anna Makowska, Franciszek Sączewski, Patrick J. Bednarski, Maria Gdaniec, Łukasz Balewski, Magdalena Warmbier and Anita Kornicka

Molecules 2022, 27(21), 7155; https://doi.org/10.3390/molecules27217155 - 22 Oct 2022

Cited by 3 | Viewed by 1999

Abstract

A series of copper(II) complexes of 2-imino-2H-chromen-3-yl-1,3,5-triazines 2a-h, 3-(benzoxazol-2-yl)-2H-chromen-2-imines 4a-b, and 3-(benzothiazol-2-yl)-2H-chromen-2-imines 6a-c were obtained by reacting of appropriate 2-iminocoumarin ligands L1a-h, L3a-b, and L5a-c with 3-fold molar excess of copper(II) chloride. The structure of these compounds was confirmed by IR spectroscopy, elemental analysis, and single-crystal X-ray diffraction data (2f, 2g, 2h, and 6c). All the synthesized complexes were screened for their activity against five human cancer cell lines: DAN-G, A-427, LCLC-103H, SISO, and RT-4 by using a crystal violet microtiter plate assay and relationships between structure and in vitro cytotoxic activity are discussed. The coordination of 2-iminocoumarins with copper(II) ions resulted in complexes 2a-h, 4a-b, and 6a-c with significant inhibitory properties toward tested tumor cell lines with IC₅₀ values ranging from 0.04 μM to 15.66 μM. In comparison to the free ligands L1a-h, L3a-b, and L5a-c, the newly prepared Cu(II) complexes often displayed increased activity. In the series of copper(II) complexes of 2-imino-2H-chromen-3-yl-1,3,5-triazines 2a-h the most potent compound 2g contained a 4-phenylpiperazine moiety at position 6 of the 1,3,5-triazine ring and an electron-donating diethylamino group at position 7′ of the 2-iminocoumarin scaffold. Among the Cu(II) complexes of 3-(benzoxazol-2-yl)-2H-chromen-2-imines 4a-b and 3-(benzothiazol-2-yl)-2H-chromen-2-imines 6a-c the most active was benzoxazole-2-iminocoumarin 4b that also possessed a diethylamino group at position 7′ of the 2-iminocoumarin moiety. Moreover, compound 4b was found to be the most prominent agent and displayed the higher potency than cisplatin against tested cell lines. Full article

(This article belongs to the Special Issue Applications of Metal Complexes)

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12 pages, 1751 KiB

Open AccessArticle

Role of the Hydroxyl Radical-Generating System in the Estimation of the Antioxidant Activity of Plant Extracts by Electron Paramagnetic Resonance (EPR)

by Daniele Sanna and Angela Fadda

Molecules 2022, 27(14), 4560; https://doi.org/10.3390/molecules27144560 - 17 Jul 2022

Cited by 3 | Viewed by 1765

Abstract

The scavenging activity of hydroxyl radicals, produced by the Fenton reaction, is commonly used to quantify the antioxidant capacity of plant extracts. In this study, three Fenton systems (Fe/phosphate buffer, Fe/quinolinic acid and Fe/phosphate buffer/quinolinic acid) and the thermal degradation of peroxydisulfate were used to produce hydroxyl radicals; the hydroxyl radical scavenging activity of plant extracts (ginger, blueberry juices and green tea infusion) and chemical compounds (EGCG and GA) was estimated by spin trapping with DMPO (5,5-dimethyl-1-pyrroline N-oxide) and EPR (Electron Paramagnetic Resonance) spectroscopy. Phosphate buffer was used to mimic the physiological pH of cellular systems, while quinolinic acid (pyridine-2,3-dicarboxylic acid) facilitates the experimental procedure by hindering the spontaneous oxidation of Fe(II). The EC₅₀ (the concentration of chemical compounds or plant extracts which halves the intensity of the DMPO–OH adduct) values were determined in all the systems. The results show that, for both the chemical compounds and the plant extracts, there is not a well-defined order for the EC₅₀ values determined in the four hydroxyl radical generating systems. The interactions of phosphate buffer and quinolinic acid with the antioxidants and with potential iron-coordinating ligands present in the plant extracts can justify the observed differences. Full article

(This article belongs to the Special Issue Applications of Metal Complexes)

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19 pages, 5419 KiB

Open AccessArticle

Potential Anticancer Activities and Catalytic Oxidation Efficiency of Platinum(IV) Complex

by Mohamed M. El-bendary, Tamer S. Saleh, Mansour M. Alomari, Ehab M. M. Ali, Bambar Davaasuren, Mariusz Jaremko and Bandar A. Babgi

Molecules 2022, 27(14), 4406; https://doi.org/10.3390/molecules27144406 - 09 Jul 2022

Cited by 6 | Viewed by 1503

Abstract

The treatment of an aqueous acetonitrile solution of chloroplatinic acid hydrate H₂PtCl₆.xH₂O and pyridine-2-carbaldehyde-oxime (paOH) in the presence of potassium thiocyanate at room temperature (25°) led to the formation of a new Pt(IV) complex with the formula [Pt(SCN)₂(paO)₂], (1). Complex 1 was fully characterized by FT-IR, UV-vis and NMR spectroscopic techniques as well as elemental analysis. The crystallographic structure of complex 1 was obtained by single-crystal X-ray diffraction. The structure of complex 1 consists of a distorted octahedral geometrical environment around the platinum center in which the coordination sites are occupied by two terminal thiocyanate ligands in trans arrangement and two bidentate paO ligands through four nitrogen atoms. In addition, the in vitro evaluation of the cytotoxicity of platinum complex 1 against four different cancer cell lines was performed. The IC₅₀ values for colon (HCT116), liver (HepG2), breast (MCF-7) and erythroid (JK-1) treated with complex 1 are 19 ± 6, 21 ± 5, 22 ± 6, and 13 ± 3 μM, respectively. In HCT116 cells treated with the IC50 dose of our title compound, apoptosis and necrosis were increased by 34% and 27.8%, respectively. Cells halted in the proliferative phase (S phase) to 21.7 % and 29.8% in HCT116 and HepG2 cells treated with complex 1 have anti-proliferative actions. Furthermore, the catalytic activity of synthesized complex 1 was examined in the oxidation reaction of benzyl alcohols in the presence of an oxidant. Finally, the luminescence behavior of complex 1 was investigated. Full article

(This article belongs to the Special Issue Applications of Metal Complexes)

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