Tin Complexes Research Articles

Superior X-ray radiation shielding of biocompatible platform based on reinforced polyaniline by decorated graphene oxide with interconnected tungsten–bismuth–tin complex

Nowadays, upon rapid advances and developments in science and technology, X-ray radiation's role in diverse kinds of applications has been highlighted. Lead, and its derivatives as preliminary shielding systems are neither light nor biocompatible. Accordingly, the demand for the fabrication of a lead-free shielding system has increased over the past few decades. To surmount the limitations mentioned above, we have synthesized a novel X-ray radiation shield based on reinforced polyaniline with hybrid graphene oxide nanoflakes decorated with an interconnected complex of tungsten-bismuth-tin, which possesses high inhibitory effects against different microorganisms. Besides, diverse kinds of characterization techniques were employed to assess the as developed nanoflakes' successful fabrication. The radiation attenuation properties of developed nanomaterials and nanocomposites were explored using X-ray (i.e., 40, 60, 80, 100 and 120 keV) transmission measurements. The increasing thickness of the shield substantially developed the attenuation efficiency because thickening the samples would intensify the adequate number of the developed nanoparticles in the pathway of incident photons. The shield's thickest layer's attenuation efficiency and linear attenuation coefficient were 98.09% and 0.4399 1.mm-1, respectively, at the photon energy of 120 keV. The obtained results of the minimum inhibitory concentration (MIC) test and cell viability assay furtherly confirmed the favourable antibacterial/antifungal effects and non-toxic nature of the developed shields. According to the results, the developed shield can be effectively used to make lighter radiation protective clothes, e.g. aprons, gonad shields, thyroid shields, and structural shielding in X-ray facilities.

In Vitro Evaluation of Antiproliferative Properties of Novel Organotin(IV) Carboxylate Compounds with Propanoic Acid Derivatives on a Panel of Human Cancer Cell Lines.

The synthesis of novel triphenyltin(IV) compounds, Ph3SnLn (n = 1–3), with oxaprozin (3-(4,5-diphenyloxazol-2-yl)propanoic acid), HL1, and the new propanoic acid derivatives 3-(4,5-bis(4-methoxylphenyl)oxazol-2-yl)propanoic acid, HL2, and 3-(2,5-dioxo-4,4-diphenylimidazolidin-1-yl)propanoic acid, HL3, has been performed. The ligands represent commercial drugs or their derivatives and the tin complexes have been characterized by standard analytical methods. The in vitro antiproliferative activity of both ligands and organotin(IV) compounds has been evaluated on the following tumour cell lines: human prostate cancer (PC-3), human colorectal adenocarcinoma (HT-29), breast cancer (MCF-7), and hepatocellular cancer (HepG2), as well as on normal mouse embryonic fibroblast cells (NIH3T3) with the aid of MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-12 diphenyltetrazolium bromide) and CV (crystal violet) assays. Contrary to the inactive ligand precursors, all organotin(IV) carboxylates showed very good activity with IC50 values ranging from 0.100 to 0.758 µM. According to the CV assay (IC50 = 0.218 ± 0.025 µM), complex Ph3SnL1 demonstrated the highest cytotoxicity against the caspase 3 deficient MCF-7 cell line. Inductively coupled plasma mass spectrometry (ICP-MS) analysis indicated a two-fold lower concentration of tin in MCF-7 cells in comparison to platinum. To investigate the mechanism of action of the compound Ph3SnL1 on MCF-7 cells, morphological, autophagy and cell cycle analysis, as well as the activation of caspase and ROS/RNS and NO production, has been performed. Results suggest that Ph3SnL1 induces caspase-independent apoptosis in MCF-7 cells.

Antimony(V) and Tin(IV) Complexes with Redox-Active O,N,O-Donor Ligand in the Electrosynthesis of Symmetrical Disulfides

Antimony(V) and Tin(IV) Complexes with Redox-Active O,N,O-Donor Ligand in the Electrosynthesis of Symmetrical Disulfides

Study of Cytotoxic and Photodynamic Activities of Dyads Composed of a Zinc Phthalocyanine Appended to an Organotin.

The combination of photodynamic therapy and chemotherapy is a promising strategy to enhance cancer therapeutic efficacy and reduce drug resistance. In this study two zinc(II) phthalocyanine-tin(IV) conjugates linked by a triethylene glycol chain were synthesized and characterized. In these complexes, the zinc(II) phthalocyanine was used as a potential photosensitizer for PDT and the tin complex was selected as cytostatic moiety. The two dyads composed of zinc(II) phthalocyanine and tin complexes exhibited high cytotoxicity, in absence of light stimulation, against MCF-7 human breast cancer cells with low LC50 values in the range of 0.016–0.453 µM. In addition, these complexes showed superior cytotoxicity than their mixture of equimolar component, accompanied with a higher activity towards cancer cells compared to human healthy fibroblasts. However, under irradiation of the zinc phthalocyanine unit (at 650 nm) no photodynamic activity could be detected, due to the most likely quenching of zinc(II) phthalocyanine singlet excited state by the nearby tin complex according to a photoinduced electron transfer process. This study demonstrates the potential of heterometallic anticancer chemotherapeutics composed of a zinc phthalocyanine and tin complex, and it highlights that the development of such conjugates requires that the sensitizer preserves its photophysical properties and in particular its singlet oxygen sensitization ability in the conjugate in order to combine the PDT activity with the cytotoxicity of the anticancer drug.

Photostabilization of Poly(vinyl chloride) Films Blended with Organotin Complexes of Mefenamic Acid for Outdoor Applications

This study develops a process for enhancing the photostabilization of PVC films blended with a low concentration of mefenamate–tin complex. One tri-substituted and three di-substituted organotin complexes containing mefenamate unit are synthesized, and their chemical structures are established. The reactions of mefenamic acid and a number of substituted tin chlorides gave the corresponding tin complexes in 70–77% yields. Tin complexes were blended with PVC and thin films. The effect of the addition of additives against long-term irradiation (290–400 nm, 300 h) is also tested. Changes in the infrared spectra, weight, and surface of the PVC blends due to irradiation are examined and analyzed. Any damage to the PVC surface and its chemical degradation level are noticeably low in the presence of additives. Minimal photodegradation levels and surface changes of the irradiated PVC films are observed when the triphenyltin complex is used. Such a complex is highly aromatic and can act as an ultraviolet irradiation absorber and a scavenger for hydrogen chloride and radicals produced due to the photooxidation and photoirradiation of PVC films.

Synthesis of Carvedilol-Organotin Complexes and Their Effects on Reducing Photodegradation of Poly(Vinyl Chloride).

Poly(vinyl chloride) (PVC) undergoes photodegradation induced by ultraviolet (UV) irradiation; therefore, for outdoor applications, its photostability should be enhanced through the use of additives. Several carvedilol tin complexes were synthesized, characterized and mixed with PVC to produce thin films. These films were irradiated at 25 °C with a UV light (λ = 313 nm) for up to 300 h. The reduction in weight and changes in chemical structure and surface morphology of the PVC films were monitored. The films containing synthesized complexes showed less undesirable changes than the pure PVC film. Organotin with a high content of aromatics was particularly efficient in inhibiting photodegradation of PVC. The carvedilol tin complexes both absorbed UV light and scavenged radicals, hydrochloride, and peroxides and, therefore, photostabilized PVC.

Apparatus-technological scheme of tin cans scrap recycling with obtaining technical products

The article is devoted to the study of reducing the technogenic load on the environment due to the integrated processing of household metal scrap. A waste-free, resource-saving, and environmentally safe method is proposed for extracting technical products from tin cans scrap - iron (III) oxide, tin (II) complex, suitable for further use, as well as fertilizer for agricultural crops. As a result of theoretical and experimental studies, the direction of cans scrap recycling was selected with an assessment of the parameters and factors affecting the reagent process of scrap disposal. To verify the proposed method for can scrap processing in experimental studies, the reagent method and physical modeling were used together. The processes of the reagent can scrap recycling were studied in a laboratory-scale plant. The results of studies on the reagent can scrap processing with the individual component allocation in the form of their derivatives are presented. A block diagram and a hardware-technological scheme for scrap processing with the receipt of technical products have been developed. The possibility of processing other metal-containing wastes according to the proposed scheme, for example, electrical production, is shown.

Bulky arene-bridged bis(amide) and bis(amidinate) complexes of germanium(II) and tin(II).

Several new, very bulky arene-bridged bis(amine) (viz. 1,3- and 1,4-{N(H)(SiPri3)}2(μ-C6H4), L1H2 and L2H2, respectively) and bis(amidine) pro-ligands (viz. 4,6-{[Dip(H)N](DipN)C}2(μ-DBF), DBF = dibenzofurandiyl, L3H2; and 1,3-{Ar†N(H)C(But)N}2(μ-C6H4), Ar† = C6H2{C(H)Ph2}2Pri-2,6,4, L4H2) have been developed. All can be doubly deprotonated with LiBun. The resultant dilithium salts react with either GeCl2·(dioxane) or SnBr2 to yield a series of amidotetrelylenecyclophanes (:E(μ-L1)2E: and :E(μ-L2)2E:, E = Ge or Sn) and bis(halotetrelylene) complexes (:E(X)(μ-L3)(X)E:, E = Ge or Sn, X = Cl or Br; and :Ge(Cl)(μ-L4)(Cl)Ge:). Reduction of :Ge(Cl)(μ-L4)(Cl)Ge: with KC8 afforded the crystallographically characterised bis(amido/amidinatogermylene) compound, :Ge(μ-L4)2Ge:, which is believed to have formed via a disproportionation process.

Synthesis, Single Crystal (XRD), Spectral Characterization (FT-IR, FT-Raman, 1HNMR, 13CNMR, 119Sn NMR), Computational (DFT), Quantum Chemical Modeling and Anticancer Activity Studies of Di(p-Bromobenzyl) (Dibromo) (1, 10-Phenanthroline) Tin (IV) Complex

The complex Di(p-bromobenzyl) (dibromo) (1, 10-phenanthroline) tin (IV) complex (4BRBR) were synthesized and experimentally proved at FT-IR, FT-Raman, 1HNMR, 13CNMR, 119SnNMR and XRD. DFT method used for comparison of theoretical and experimental method, theoretical method optimized to use for B3LYP/LanL2DZ basic set level. The complete vibrational spectral investigation was designed from VEDA program package. Quantum chemical calculated with help of Multiwfn software package. X-ray study confirmed the complex and crystallization by monoclinic space group with P21/c, hydrogen bonding formed through bromine atom such as C---H---Br (Sn-Br---H-Phen), and weak interaction observed at C---H---Br. The crystal of the complex 4BRBR shows tin atom is in regular octahedral geometry. Finally anticancer activity also studied in this complex in various cell lines like PC3 (Human prostate cancer cell), MCF7 (Breast cancer cell), U937 (Blood cancer cell) and U87 Brain cancer cell). The anticancer activity results clearly indicate the MCF7 cell line (Breast cancer cell) has higher anticancer activity compared to standard drug cisplatin and other cell lines which is 7.8 µg/ml concentrations.

Rational Preparation of Atomically Precise Non-Alkyl Tin-Oxo Clusters with Theoretical to Experimental Insights into Electrocatalytic CO 2 Reduction Applications

Tin oxides (SnO2) have been widely utilized in electronics, nanolithography, and catalysis. As the atomically precise models of SnO2, tin-oxo clusters (TOCs) not only provide opportunities for mech...

Tin Complexes Containing an Atenolol Moiety as Photostabilizers for Poly(Vinyl Chloride)

The lifetime of poly(vinyl chloride) (PVC) can be increased through the addition of additives to provide protection against irradiation. Therefore, several new tin complexes containing atenolol moieties were synthesized and their photostabilizing effect on PVC was investigated. Reacting atenolol with a number of tin reagents in boiling methanol provided high yields of tin complexes. PVC was then mixed with the tin complexes at a low concentration, producing polymeric thins films. The films were irradiated with ultraviolet light and the resulting damage was assessed using different analytical and surface morphology techniques. Infrared spectroscopy and weight loss determination indicated that the films incorporating tin complexes incurred less damage and less surface changes compared to the blank film. In particular, the triphenyltin complex was very effective in enhancing the photostability of PVC, and this is due to its high aromaticity (three phenyl rings) compared to other complexes. Such an additive acts as a hydrogen chloride scavenger, radical absorber, and hydroperoxide decomposer.

Synthesis and characterization of organotin(IV) semiconductors and their applications in optoelectronics

A new series of organotin(IV) semiconductors derived from aryl hydroxymethylidene indanones has been synthesized and characterized. The products have been examined as hole-injection layers (HILs) in the fabrication of electronic devices. Their structures have been optimized by density functional theory (DFT), and the energy values of the highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO), as well as their UV/Vis spectra, have been characterized. In order to study the electronic behavior of the organotin(IV) semiconductors, hetero-junction devices have been manufactured by a vacuum deposition process. Organic devices of the type glass/ITO/organotin(IV) complex/ZnPc/bathocuproine/Ag have been assembled by sequential sublimatory deposition. The devices have been characterized by X-ray diffraction (XRD), which revealed a considerable degree of crystallinity and a defined growth pattern in their constituent films. The optical band-gaps of the semiconductors in the devices have been measured to determine their electrical I(V) characteristics and hence their behavior as HILs. UV/Vis analysis has revealed that the deposition process generates flat hetero-junction structures free from impurities that are transparent to visible radiation and have an optical band-gap between 2.83 and 2.95 eV. On increasing the temperature, the devices show symmetrical J(V) behavior, indicative of ambipolarity. In both natural light and darkness, the devices show ohmic behavior at low voltages and space-charge-limited behavior at higher voltages. These dibutyltin(IV) complexes of 2-hydroxybenzylidene-1-indanone derivatives have proved to be suitable as HILs, and their behavior directly depends on radicals present in the tin complex.

3,6-Di-tert-Butyl-2-Hydroxy-4-Pyridinylphenolate and Tin(IV) Complexes it Forms: Synthesis and Structure Details and Solvatochromic Effect

Two synthetic approaches were developed for the preparation of 3,6-di-tert-butyl-2-hydroxy-4-pyridinylphenolate (LH), a new zwitter-ionic redox-active diolate type ligand. Two heteroligand five-coordinate tin(IV) derivatives were prepared with this ligand: 3,6-di-tert-butyl-2-oxy-4-pyridinylphenolato(triphenyl)tin(IV) (I) and 3,6-di-tert-butyl-2-oxy-4-pyridinylphenolato(diphenyl)chlorotin(IV) (II). The molecular structures of the ligand LH ∙ 0.5Py and complex I ∙ CH3CN were determined by X-ray diffraction (CIF files CCDC nos. 1974166 (LH), 1974165 (I)). It was shown that the ligand LH and the tin(IV) compound exhibit solvatochromism, which consists in a considerable blue shift with increasing solvent polarity.

VIBRATIONAL SPECTRA IN THE FAR IR REGION AND EFFECTS OF SUBSTITUENTS IN o-IMINOSEMIQUINONE TIN(IV) COMPLEXES

We report a comparative analysis of experimental and theoretical vibrational spectra recorded in the frequency region of 700-100 cm–1 for mono-o-iminosemiquinone tin(IV) complexes with general formulas LSnR2Cl (1-5) and LSnR3 (6, 7) (L is the 4,6-di-tert-butyl-N-(2,6-di-iso-propylphenyl)-o-iminobenzoquinone radical anion, R = Me (1, 6), Et (2), n-Bu (3), t-Bu (4), Ph (5, 7)). It is established that absorption bands of ν(Sn–O) and ν(Sn–N) stretching vibrations in the studied compounds occur at 460-360 cm–1 and 340-350 cm–1, respectively. The position of the ν(Sn–O) absorption band correlates with the Sn–O bond length. In particular, the band is redshifted by 20 cm–1 in complex 6, where this bond is 0.2 A longer than in other compounds. It is shown that parameters ν(Sn–O), a(117, 119Sn) and bond lengths d(Sn–O), d(Sn–N), and d(Sn–C) in the complexes depend on four (inductive, resonance, polarization, and steric) effects of tin-bonded substituents.

Triorganotin complexes in cancer chemotherapy: Mechanistic insights and future perspectives

Current anticancer drug discovery and development efforts are aimed at identifying new complexes that can potently and selectively target DNA and modulate the functions of target proteins. Tin complexes, categorized as monoorganotin (RSnL3), diorganotin (R2SnL2), triorganotin (R3SnL), or tetraorganotin (R4SnL), are one of the most studied complexes in the metal‐based anticancer drug discovery and development field. Among these, diorganotins and triorganotins are widely reported to possess promising anticancer properties, with triorganotins offering several potential advantages over diorganotins, such as a higher total surface area causing higher lipophilicity and hence higher cytotoxicity in cancer cells. However, information on triorganotins' direct therapeutic targets, an in‐depth understanding of their mechanism of action, and useful therapeutic strategies are still lacking. In this review, we discuss the results from in vitro and in vivo mechanistic studies of triorganotin complexes as reported in recent years (2007–2019) and elaborate on the underlying mechanisms that could aid in the identification of triorganotin complex molecular targets. We conclude by identifying present obstacles faced by triorganotin complexes that avert their translation to the clinical phase and current strategies employed to overcome the aforementioned obstacles, and we offer considerations for their future development. These findings are anticipated to stimulate further developments of novel and innovative triorganotin complexes as anticancer drug candidates.

Triorganotin(IV) derivatives with semirigid heteroditopic hydroxo‐carboxylato ligands: Synthesis, characterization, and cytotoxic properties

Three organic hydroxy‐carboxylic acids separated by a semirigid aromatic diaza scaffold and carrying alkyl groups of different steric hindrance (H′HL1, cyclopropyl; H′HL2, cyclohexyl; H′HL3, adamantyl) were employed as pro‐ligands. Their reaction with suitable triorganotin precursors leads to 10 complexes of compositions: [Me3Sn(HL1)]n·0.5nC6H5CH3 1, [Et3Sn(HL1)]n 2, [nBu3Sn(HL1)]n 3, [Ph3Sn(HL1)]n 4, [Me3Sn(HL2)]2·2CH2Cl2 5, [Et3Sn(HL2)]2 6, {[nBu3Sn(HL2)][nBu3Sn(HL2)(H2O)]} 7, [Ph3Sn(HL2)]n·nC2H5OH 8, [nBu3Sn(HL3)]n 9, and [Ph3Sn(HL3)]n 10. The solid‐state structures of 1–10 were deduced from single‐crystal X‐ray diffraction studies along with two of the pro‐ligands: H′HL1 and H′HL2. In the solid state, four different extended structure types were observed. In compounds 1–3 with aliphatic substituents at the tin atoms and a small substituent at the ligand backbone (cyclopropyl), 1D coordination polymers based on carboxylate bridging were observed, whereas compounds 4 and 8–10 with large substituents attached to the metal and the ligand (cyclohexyl and adamantyl) were 1D coordination polymers based on heteroditopic binding of the ligands. Albeit having essentially the same ligand conformation, the compounds having smaller substituents at the tin atoms (5, R = Me; 6, R = Et) comprise 24‐membered macrocyclic ring structures. In 7, water molecules are coordinated to half the tin atoms, giving dinuclear fragments {[HL2][nBu3Sn][HL2][nBu3Sn(H2O)]}, which are linked through OwH···Osal hydrogen bonds into 1D hydrogen‐bonded tapes. In solution, the tin atoms in 1–10 are coordinated to a single monoanionic [HL1–3]− ligand molecule utilizing anisobidentate coordination with the carboxylate group, as revealed from 119Sn nuclear magnetic resonance spectral results. The antiproliferative activity of the tri‐n‐butyl and triphenyltin compounds 3, 4, and 7–10 was evaluated against the cervical cancer cells (HeLa) and normal kidney cells (HEK) using the 3‐(4,5‐dimethylthiazol‐2‐yl)‐2,5‐diphenyltetrazolium bromide assay. Of these, the adamantyl‐substituted tin complexes 9 and 10 present increased activity with IC50 values of 0.51 ± 0.01 and 0.41 ± 0.03 (μM) and good selectivity. The cell death mechanism was identified as apoptosis based on dual staining with fluorescent dyes (Hoechst 33342/propidium iodide and acridine orange/ethidium bromide) and might be related to reactive oxygen species.

PVC Films Performance Stabilized By Dibutyltin (IV) Complex For Sustainable Environment

A new tin(IV) complex was synthesized to inhibit the effect of UV light on PVC films. The new dibutyl tin(IV) complex coordinated to captopril as a ligand (Bu2SnL2) were used as additive to reduce the deterioration of PVC films under irradiation of UV light. Tin (IV) complex efficiency was examined under accelerated UV irradiation conditions for 300h at ambient temperature. The shifts in the FTIR index of hydroxyl, carbonyl and carbine, in addition to changes in weight, viscosity and surface morphology was used to evaluate the performance of the new complex as a photostabilizer for PVC films.

Synthesis, single-crystal X-ray diffraction, and in vitro biological evaluation of sodium, cobalt, and tin complexes of o-nitro-/o-methoxyphenylacetic acid: experimental and theoretical investigation

Four new metal carboxylates with o-nitro- and o-methoxyphenylacetic acid were synthesized and well characterized using single-crystal XRD. The synthesized complexes were evaluated for their biological potentials (antibacterial, antifungal, antioxidant, and enzyme inhibition) according to reported methods. Four bacterial and two fungal strains were targeted in this study and it was concluded that the synthesized compounds showed activities comparable to standard drugs. Co complex of nitro and tin complex of methoxy substituent are more active against bacterial as well as fungal strains. Enzyme inhibition activity of the synthesized compound was evaluated against acetylcholine esterase, butyrylcholine esterase, and trypsin. The maximum activity was depicted by Co complex of nitro, while all other tested compounds had moderate to good activity. DFT calculations were performed to gain further insight into the spectral properties. Docking model was also used to check the interaction of most active compound on the active site of the enzyme. All theoretical parameters supported the practical calculation and our findings that such compounds may be the best molecules in the near future against infectious as well as Alzheimer disease.

A Surface Morphological Study, Poly(Vinyl Chloride) Photo-Stabilizers Utilizing Ibuprofen Tin Complexes against Ultraviolet Radiation

In this work, three Ibuprofen tin complexes were synthesized and characterized by Fourier Transform Infrared spectroscopy (FTIR), 1H and 119Sn-Nuclear Magnetic Resonance (NMR), and Energy Dispersive X-ray (EDX) spectroscopies to identify the structures. The complexes were mixed separately with poly(vinyl chloride) (PVC) to improve its photo-stability properties. Their activity was demonstrated by several approaches of the FTIR to exhibit the formation of new groups within the polymer structure due to the exposure to UV light. Moreover, the polymer’s weight loss during irradiation and the average molecular weight estimation using its viscosity before and after irradiation were investigated. Furthermore, different techniques were used to study the surface morphology of the PVC before and after irradiation. Field-emission scanning electron microscopy (FESEM) and optical microscope demonstrated that applying Ibuprofen tin complexes keeps the surface of PVC smoother, with fewer cracks and spots after irradiation comparing to the blank PVC. Finally, It seems possible that such synthesized Ibuprofen tin complexes can work as excellent photo-stabilizers of PVC. In particular, complex 1 showed the best results among other stabilizers due to the large conjugation system of the stabilizer.

Syntheses, crystal structures and catalytic property of two bulky tin(II) complexes

Two bulky three-coordinate tin(II) complexes 1 and 2 have been prepared: [N(Ar)C(R)NC(R)N(R′)]SnCl (Ar = 2,6-iPr2C6H3, R = NMe2, R′ = H, 1; R = 1-piperidino, R′ = SiMe3, 2). Their single-crystal X-ray diffraction studies are presented. They can be used as efficient pre-catalysts for catalytic addition of arylamines to N,N'-diisopropylcarbodiimide.