The Anti-Proliferative Activity of Coordination Compound-Based ZnO Nanoparticles as a Promising Agent Against Triple Negative Breast Cancer Cells.

PURPOSE: The present study deals with the in vitro evaluation of the potential use of coordination compound-based zinc oxide (ZnO) nanoparticles (NPs) for the treatment of triple negative breast cancer cells (TNBrCa). As BrCa is one of the most prevalent cancer types and TNBrCa treatment is difficult due to poor prognosis and a high metastasis rate, finding a more reliable treatment option should be of the utmost interest. METHODS: Prepared by reacting zinc carboxylates (formate, acetate, propionate, butyrate, isobutyrate, valerate) and hexamethylenetetramine, 4 distinct coordination compounds were further subjected to two modes of conversion into ZnO NPs - ultrasonication with oleic acid or heating of pure precursors in an air atmosphere. After detailed characterization, the resulting ZnO NPs were subjected to in vitro testing of cytotoxicity toward TNBrCa and normal breast epithelial cells. Further, their biocompatibility was evaluated. RESULTS: The resulting ZnO NPs provide distinct morphological features, size, biocompatibility, and selective cytotoxicity toward TNBrCa cells. They internalize into two types of TNBrCa cells and imbalance their redox homeostasis, influencing their metabolism, morphology, and ultimately leading to their death via apoptosis or necrosis. CONCLUSION: The crucial properties of ZnO NPs seem to be their morphology, size, and zinc content. The ZnO NPs with the most preferential values of all three properties show great promise for a future potential use in the therapy of TNBrCa.

First experimental evidence of the piezoelectric nature of struvite.

In this paper, we present the first experimental evidence of the piezoelectric nature of struvite (MgNH4PO4·6H2O). Using a single diffusion gel growth technique, we have grown struvite crystals in the form of plane parallel plates. For struvite crystals of this shape, we measured the piezoelectric coefficients d33 and d32. We have found that at room temperature the value of piezoelectric coefficient d33 is 3.5 pm/V, while that of d32 is 4.7 pm/V. These values are comparable with the values for other minerals. Struvite shows stable piezoelectric properties up to the temperature slightly above 350 K, for the heating rate of 0.4 K/min. For this heating rate, and above this temperature, the thermal decomposition of struvite begins, which, consequently, leads to its transformation into dittmarite with the same non-centrosymmetric symmetry as in case of struvite. The struvite-dittmarite transformation temperature is dependent on the heating rate. The higher the heating rate, the higher the temperature of this transformation. We have also shown that dittmarite, like struvite exhibits piezoelectric properties.

Influence of n-ZnO Morphology on Sulfur Crosslinking and Properties of Styrene-Butadiene Rubber Vulcanizates.

This paper examines the influence of the morphology of zinc oxide nanoparticles (n-ZnO) on the activation energy, vulcanization parameters, crosslink density, crosslink structure, and mechanical properties in the extension of the sulfur vulcanizates of styrene-butadiene rubber (SBR). Scanning electron microscopy was used to determine the particle size distribution and morphology, whereas the specific surface area (SSA) and squalene wettability of the n-ZnO nanoparticles were adequately evaluated using the Brunauer-Emmet-Teller (BET) equation and tensiometry. The n-ZnO were then added to the SBR in conventional (CV) or efficient (EV) vulcanization systems. The vulcametric curves were plotted, from which the cure rate index (CRI) rate of the vulcanization and the activation energy were calculated. The influence on the mechanical properties of the SBR vulcanizates was stronger in the case of the EV curing system than when the CV curing system was used. Of the vulcanizates produced in the EV curing system, the best performance was detected for n-ZnO particles with a hybrid morphology (flat-ended rod-like particles on a "cauliflower" base) and high SSA. Vulcanizates produced using the CV curing system showed slightly better mechanical properties after the addition of nanoparticles with a "cauliflower" morphology than when the rod-like type were used, irrespective of their SSA. In general, nanoparticles with a rod-like structure reduced the activation energy and increased the speed of vulcanization, whereas the cauliflower type slowed the rate of the process and the vulcanizates required a higher activation energy, especially when using the EV system. The crosslink structures were also more clearly modified, as manifested by a reduction in the polysulfidic crosslink content, especially when n-ZnO activators with a rod-like morphology were applied.

Molecular self-assembly of 1D infinite polyiodide helices in a phenanthrolinium salt.

A new linear polymeric polyiodide, catena-poly[tris(1,10-phenanthrolin-1-ium)tris(1,10-phenanthroline)heptaiodide], was prepared by one-step synthesis. Its formation is driven by hydrogen-bond assisted supramolecular assembly in the presence of chromium(iii) acetate. Its structure has been characterized by the means of single-crystal X-ray diffraction. To date, this is only one of the few examples of organized linear infinite polyiodides with a known structure. The interplay between the interactions within the hypervalent iodine chain and its supramolecular environment is elucidated. The electrical, thermal, and spectroscopic properties of the studied compound were investigated and associated with the structural features. The infinite character of the polyiodide chain and its similarity to the blue starch-iodine complex has been additionally confirmed by Raman spectroscopy. Despite the apparent structural and spectroscopic similarities with the previously reported 1D polymeric polyiodide, its physical properties, i.e. electrical conductivity and thermal stability, differ significantly. This can be rationalized by the differences in the orbital overlap within the iodine chain, as well as the distinct interactions with the cation.

Five new complexes with deferiprone and N,N-donor ligands: evaluation of cytotoxicity against breast cancer MCF-7 cell line and HSA-binding determination.

In this study, five new complexes containing deferiprone (dfp) and N,N-donor ligands [bipyridine (bpy), 1,10-phenanthroline (phen) and ethylenediamine (en)] were synthesized: [Fe(dfp)2(bpy)](PF6) (1), [Fe(dfp)2(phen)](PF6) (2), [Cu2(dfp)2(bpy)2](PF6)2 (3), [Ga(dfp)2(bpy)](PF6) (4), and [Fe(dfp)2(en)](PF6) (5). Characterization of these complexes was carried out through elemental analysis and FT-IR, and single-crystal X-ray crystallography was used to determine their structures. Whilst the polyhedron has a distorted octahedral geometry in 1, 2, 4, and 5, it adopts a distorted square-pyramidal geometry in 3. Interaction of these compounds with human serum albumin (HSA) has been investigated through electronic absorption and fluorescence titration techniques. Emission quenching was performed separately for each complex at three different temperatures and thermodynamic parameters were calculated using binding constants to better understand the power of different binding forces with the HSA. Results demonstrated that compounds interact strongly with the HSA with a static quenching mechanism. Our evaluation of the cytotoxicity of complexes against the breast cancer MCF-7 cell line showed that complex 2 presents a better cytotoxicity than the standard cis-Pt. Finally, using the AutoDock 4.2 program, simulations to analyze the mechanism of complex-HSA interactions and their binding mode were carried out. Results showed that the best binding mode is located in subdomain IB for 1, 2, and 4, in I/II for 3, and in IA/IIA for 5. Communicated by Ramaswamy H. Sarma.

Dinuclear uranium(VI) salen coordination compound: an efficient visible-light-active catalyst for selective reduction of CO2 to methanol.

A new dinuclear uranyl salen coordination compound, [(UO2)2(L)2]·2MeCN [L = 6,6'-((1E,1'E)-((2,2-dimethylpropane-1,3-diyl)bis(azaneylylidene))-bis(methaneylylidene))bis(2-methoxyphenol)], was synthesized using a multifunctional salen ligand to harvest visible light for the selective photocatalytic reduction of CO2 to MeOH. The assembling of the two U centers into one coordination moiety via a chelating-bridging doubly deprotonated tetradentate ligand allowed the formation of U centers with distorted pentagonal bipyramid geometry. Such construction of compounds leads to excellent activity for the photocatalytic reduction of CO2, permitting a production rate of 1.29 mmol g-1 h-1 of MeOH with an apparent quantum yield of 18%. Triethanolamine (TEOA) was used as a sacrificial electron donor to carry out the photocatalytic reduction of CO2. The selective methanol formation was purely a photocatalytic phenomenon and confirmed using isotopically labeled 13CO2 and product analysis by 13C-NMR spectroscopy. The spectroscopic studies also confirmed the interaction of CO2 with the molecule of the title complex. The results of these efforts made it possible to understand the reaction mechanism using ESI-mass spectrometry.

Structural and Theoretical Investigations, Hirshfeld Surface Analyses, and Cytotoxicity of a Naphthalene-Based Chiral Compound.

A novel Schiff base compound derived from the condensation of 2-hydroxy-1-naphthaldehyde with (1S,2S)-(-)-1,2-diphenylethylenediamine in 2:1 M ratio was reported and investigated by elemental analyses, Fourier transform infrared and NMR spectroscopic studies, and single-crystal X-ray crystallography. Hirshfeld surface analyses were also carried out to measure the various intermolecular contacts controlling the supramolecular topology, suggesting the H···O (7.6%) contacts to be the most significant interactions, whereas the H···H (48.9%) and C···H (40.2%) interactions are less-significant. The data obtained from the energy calculations revealed the structure observed experimentally to be the most stable isomer and its energy being lower by 18.0441 kcal/mol than the less stable one. Density functional theory calculations were also carried out to analyze the natural charges, reactivity descriptors, and different intramolecular charge transfer interactions. The in vitro anticancer activity of the compound was evaluated by MTT assays against human colorectal cancer cells, HT-29 and SW620. The results showed that the compound has potential anticancer activity against these cells lines.

Physicochemical Insight into Coordination Systems Obtained from Copper(II) Bromoacetate and 1,10-Phenanthroline.

Two different coordination compounds of copper were synthesized from the same building blocks (1,10-phenanthroline, bromoacetate anions, and copper cations). The synthesis parameters were carefully designed and evaluated to allow the change of the resulting compounds molecular structure, i.e., formation of mononuclear (bromoacetato-O,O')(bromoacetato-O)aqua(1,10-phenanthroline-N,N')copper(II) and dinuclear (µ-bromido-1:2κ2)bis(µ-bromoacetato-1κO,2κO')bis(1,10-phenanthroline-N,N')dicopper(II) bromoacetate bromoacetic acid solvate. The crystal, molecular and supramolecular structures of the studied compounds were determined and evaluated in Hirshfeld analysis. The UV-Vis-IR absorption and thermal properties were studied and discussed. For the explicit determination of the influence of compounds structure on radiation absorption in UV-Vis range, density functional theory and time-dependent density functional theory calculations were performed.

1,3,4-Thiadiazole-Containing Azo Dyes: Synthesis, Spectroscopic Properties and Molecular Structure.

Three series of azo dyes derived from 2-amino-5-aryl-1,3,4-thiadiazoles and aniline, N,N-dimethylaniline and phenol were synthesized in high yields by a conventional diazotization-coupling sequence. The chemical structures of the prepared compounds were confirmed by 1H-NMR, 13C-NMR, IR, UV-Vis spectroscopy, mass spectrometry and elemental analysis. In addition, the X-ray single crystal structure of a representative azo dye was presented. For explicit determination of the influence of a substituent on radiation absorption in UV-Vis range, time-dependent density functional theory calculations were performed.

Photoluminescence enhancement of Re(i) carbonyl complexes bearing D-A and D-π-A ligands.

Three Re(i) carbonyl complexes [ReCl(CO)3(Ln)] bearing 2,2'-bipyridine, 2,2':6',2''-terpyridine, and 1,10-phenanthroline functionalized with diphenylamine/or triphenylamine units (L1-L3) were synthesized to explore the impact of highly electron donating units appended to the imine ligand on the thermal and optoelectronic properties of Re(i) systems. Additionally, for comparison, the ligands L1-3 and parent complexes [ReCl(CO)3(bipy)], [ReCl(CO)3(phen)] and [ReCl(CO)3(terpy-κ2N)] were investigated. The thermal stability was evaluated by differential scanning calorimetry. The ground- and excited-state electronic properties of the Re(i) complexes were studied by cyclic voltammetry and differential pulse voltammetry, absorption and emission spectroscopy, as well as using density-functional theory (DFT). The majority of the compounds form amorphous molecular materials with high glass transition temperatures above 100 °C. Compared to the unsubstituted complexes [ReCl(CO)3(bipy)], [ReCl(CO)3(phen)] and [ReCl(CO)3(terpy-κ2N)], the HOMO-LUMO gap of the corresponding Re(i) systems bearing modified imine ligands is reduced, and the decrease in the value of the ΔEH-L is mainly caused by the increase in HOMO energy level. In relation to the parent complexes, all designed Re(i) carbonyls were found to show enhanced photoluminescence, both in solution and in solid state. The investigated ligands and complexes were also preliminarily tested as luminophores in light emitting diodes with the structures ITO/PEDOT:PSS/compound/Al and ITO/PEDOT:PSS/PVK:PBD:compound/Al. The pronounced effect of the ligand chemical structure on electroluminescence ability was clearly visible.

Interplay between Polymorphism and Isostructurality in the 2-Fur- and 2-Thenaldehyde Semi- and Thiosemicarbazones.

The four compounds, namely: 5-nitro-2-furaldehyde thiosemicarbazone (1); 5-nitro-2-thiophene thiosemicarbazone (2); 5-nitro-2-furaldehyde semicarbazone (3); and 5-nitro-2-thiophene semicarbazone (4) were synthesized and crystallized. The three new crystal structures of 1, 2, and 4 were determined and compared to three already known crystal structures of 3. Additionally, two new polymorphic forms of 1 solvate were synthesized and studied. The influence of the exchange of 2-thiophene to 2-furaldehyde as well as thiosemicarbazone and semicarbazone on the self-assembly of supramolecular nets was elucidated and discussed in terms of the formed synthons and assemblies accompanied by Full Interaction Maps analysis. Changes in the strength of IR oscillators caused by the molecular and crystal packing effects are described and explained in terms of changes of electron density.

Copper(I) complexes with phosphines P(p-OCH3-Ph)2CH2OH and P(p-OCH3-Ph)2CH2SarGly. Synthesis, multimodal DNA interactions, and prooxidative and in vitro antiproliferative activity.

Phosphonium salt (p-OCH3-Ph)2P(CH2OH)2Cl (MPOHC), derived phosphine ligands without and with SarGly (Sarcosine-Glycine) peptide carrier P(p-OCH3-Ph)2CH2OH (MPOH) and P(p-OCH3-Ph)2CH2SarGly (MPSG), respectively, and two copper(I) complexes [Cu(I)(dmp)(MPOH)] (1-MPOH; dmp = (2,9-dimethyl-1,10-phenanthroline)) and [Cu(I)(dmp)(MPSG)] (1-MPSG) were synthesized. The resulting compounds were characterized by elemental analysis, 1D and 2D NMR and UV-Vis absorption spectroscopies, mass spectrometry, cyclic voltammetry and by X-ray diffraction analysis. Cytotoxicity of all compounds was evaluated in vitro against colon, lung, breast, pancreatic, prostate tumor cell lines, as well as towards non-tumor cell lines: lung, kidney and keratinocyte. Stable in biological medium in the presence of atmospheric oxygen, Cu(I) complexes exerted a cytotoxic effect higher than that elicited by cisplatin against tested cancer cell lines. The introduction of methoxy group onto the phenyl rings of the phosphine ligand coordinated to the copper(I) ion resulted in a relevant increase of cytotoxicity in the case of breast, pancreatic and prostate tumor cell lines in vitro. Attachment of a peptide carrier significantly increased the selectivity towards cancer cells. Fluorescence spectroscopic data (calf thymus DNA: CT-DNA) titration), together with analysis of DNA fragmentation (gel electrophoresis) and molecular docking provided evidence for the multimodal interaction of copper compounds with DNA and showed their unusual low genotoxicity. Additionally, copper complexes were able to generate reactive oxygen species as a result of redox processes, proved by fluorescence spectroscopy and cyclic voltamperometry.

Influence of the pyrazine substituent on the structure and magnetic properties of dicyanamide-bridged cobalt(ii) complexes.

Substituted pyrazines were successfully used to prepare two new coordination polymers of formulas {[Co(dca)2(NH2pyz)2]·H2O}n (1) and [Co3(dca)6(HOpyz)5(H2O)2]n (2) [dca = dicyanamide, NH2pyz = 2-aminopyrazine and HOpyz = 2-hydroxypyrazine] whose structures were determined by single-crystal X-ray crystallography. The structure of 1 consists of a two-dimensional rhombus grid of cobalt(ii) ions where the dca ligand adopts the µ1,5 bridging mode with trans-positioned monodentate NH2pyz molecules completing the six-coordination around each metal ion. Compound 2 exhibits a stair-like two-dimensional structure where the intralayer connections are performed by the dca and HOpyz groups exhibiting µ1,5 and bis-monodentate coordination modes, respectively. The values of the cobalt-cobalt separation through the dca bridges are 8.2107(3) (1) and 8.4746(4) and 8.5249(4) Å (2) whereas the value through the hydroxypyrazine is 7.2052(6) Å (2). Solid-state direct-current magnetic susceptibility analyses in the temperature range of 1.9-300 K for 1 and 2 reveal the occurrence of magnetically isolated high-spin cobalt(ii) ions with a significant contribution to the magnetic moment (1 and 2), D = +95.4 (1) and +76.5 cm-1 (2) and the antiferromagnetically coupled pairs of cobalt(ii) centres through the bis-monodentate 2-hydroxypyrazine, J = -0.3 cm-1 (2). Both compounds exhibit frequency dependence of the out-of-phase alternating current (ac) magnetic susceptibility (χ''M) under non-zero applied dc fields, a feature which is characteristic of single-ion magnet behaviour (SIM). Q-band EPR studies on the polycrystalline samples of 1 and 2 at low temperatures confirm the positive sign of D and reveal the occurrence of a strong asymmetry in the g-tensors. Theoretical calculations by CASSCF/NEVPT2 support these results. An analysis of the dynamic behaviour of 1 and 2 suggests that the relaxation of the magnetization occurs in the ground state under applied fields through two Orbach processes possibly bound to low-lying vibrational modes in the high temperature range, and to the slowing down of the fast interconversion between the two contributions of the ground Kramers doublet at lower temperatures induced by the applied dc field.

Structural Insights into Influence of Isomerism on Properties of Open Shell Cobalt Coordination System.

The two coordination compounds of cobalt were designed and synthesized. The substrates were carefully selected to allow gentle tuning of the molecular structure of the designed compounds. The crystal, molecular and supramolecular structure of studied compounds has been determined and discussed. The spectroscopic and thermal properties of designed coordination compounds have been studied and their application as precursors for the synthesis of cobalt oxide nanoparticles has been demonstrated. It was proven that not only are parameters of conversion of the precursor to nanoparticles important, but also small changes in molecular structure can considerably affect the size of formed particles. For unambiguous determination of the influence of compounds structure on their UV-Vis radiation absorption, density functional theory and time-dependent density functions theory calculations have been performed. The complexity of the correct ab-initio reflection of the open shell molecular system was outlined and discussed. The results obtained from density functional theory (DFT) calculations have been also employed for discussion of the bonding properties.

Copper(ii) complexes with 2,2':6',2''-terpyridine, 2,6-di(thiazol-2-yl)pyridine and 2,6-di(pyrazin-2-yl)pyridine substituted with quinolines. Synthesis, structure, antiproliferative activity, and catalytic activity in the oxidation of alkanes and alcohols with peroxides.

A series of 2,2':6',2''-terpyridine (terpy), 2,6-di(thiazol-2-yl)pyridine (dtpy) and 2,6-di(pyrazin-2-yl)pyridine (dppy) derivatives with n-quinolyl substituents (n = 2 and 4) was used to synthesize five-coordinate complexes [CuCl2(n-quinolyl-terpy)] (1-2), [CuCl2(n-quinolyl-dtpy)] (3-4) and [CuCl2(n-quinolyl-dppy)] (5-6), respectively. The main emphasis of the research was to investigate the impact of the triimine skeleton (terpy, dtpy and dppy) and n-quinolyl pendant substituent on the antiproliferative and catalytic properties of 1-6. The obtained Cu(ii) compounds were studied as antiproliferative agents against human colorectal (HCT116) and ovarian (A2780) carcinoma, and they were used as catalysts for the oxidation of alkanes and alcohols with peroxides under mild conditions. The kinetic characteristics of the oxidizing species generated by the catalytic system Cu(ii) complex-H2O2 in CH3CN were obtained from the dependence of the alkane oxidation rate on its initial concentration. A model of competitive interaction of hydroxyl radicals with CH3CN and RH in the catalyst cavity has been proposed which is based on the simultaneous study of kinetics and selectivity in alkane oxidations.

Synthesis of 4-Alkyl-4H-1,2,4-triazole Derivatives by Suzuki Cross-coupling Reactions and Their Luminescence Properties.

New derivatives of 4-alkyl-3,5-diaryl-4H-1,2,4-triazole were synthesized utilizing the Suzuki cross-coupling reaction. The presented methodology comprises of the preparation of bromine-containing 4-alkyl-4H-1,2,4-triazoles and their coupling with different commercially available boronic acids in the presence of ionic liquids or in conventional solvents. The obtained compounds were tested for their luminescence properties.

Folic acid-mediated re-shuttling of ferritin receptor specificity towards a selective delivery of highly cytotoxic nickel(II) coordination compounds.

Metal-based coordination compounds, including the well-known cytostatic drug cisplatin, are widely used in the anticancer therapy. Generally, they exhibit high cytotoxicity not only towards malignant cells, but also towards non-malignant cells, which represents main problem of their clinical use. Herein, we describe the synthesis, characterization and biological testing of three trinuclear nickel(II) coordination compounds. Central nickel atoms are bridged by trithiocyanurate anion and coordinated by triamine and bis-benzimidazoles, respectively. To delineate a potential usage in anticancer therapy, we encapsulated the most cytotoxic complex into biomacromolecular protein cage apoferritin (FRT), forming FRTNi. FRT encapsulation markedly decreased the hemotoxicity of free Ni compounds. Despite FRTNi can be internalized through passive targeting by enhanced permeability and retention effect, we further introduced active targeting utilizing folate receptor (FR) via folic acid (FA)-modified FRT (FRTNiFA). Using breast cancer cell lines T-47D (FR+), MCF-7 (FR-) and non-malignant mammary gland derived cell line HBL-100 (FR-), we show pronounced FR-dependent internalization of FRTNiFA. Overall, we demonstrate that the FRT macromolecular nanocarrier provides a very low off-target toxicity, which could enable the use of highly toxic Ni compounds in cancer nanomedicine.

Synthesis and structural characterization of antimicrobial binuclear copper(II) coordination compounds bridged by hydroxy- and/or thiodipropionic acid.

In the present study, two binuclear copper(II) coordination compounds bridged by hydroxy- and thiodipropionic acid have been synthesized. The structure of compounds was determined by X-ray crystallography. The central copper atoms exist in square pyramidal surroundings. Basal plane is formed by nitrogen atoms of amines and oxygen atoms of bridges, whereas apical positions are occupied by oxygen atoms of coordinated water molecules. Temperature dependence study of magnetic susceptibility proved strong antiferromagnetic exchange between copper atoms in hydroxy-bridged complex. These coordination compounds were also tested for their biological activities in vitro. Both coordination compounds exhibit pronounced cytocompatibility in mammalian epithelial cells with no induction of oxidative stress and DNA fragmentation. Moreover, synthesized compounds are hemocompatible and do not alter expression of a marker of multiple cellular stress, p53. On the other hand, both compounds had stimulatory effect on expression of metallothioneins (MT-1/2 and MT-3). Antimicrobial testing on Escherichia coli, Staphylococcus aureus and methicillin-resistant Staphylococcus aureus revealed that both copper compounds exhibit antibacterial activity regardless the cell wall composition. Overall, current work presents a synthesis of Cu(II) coordination compounds with interesting biological behavior and with a promising potential to be further tested in pre-clinical models.

New fluorescent compounds based on zinc thiocyanate: influence of structure on spectral properties.

New coordination compounds based on zinc thiocyanate, namely (acetone thiosemicarbazone-κ2N1,S)bis(isothiocyanato-κN)zinc(II) monohydrate, [Zn(NCS)2(C4H9N3S)]·H2O, (I), and diaquatetrakis(urea-κO)zinc(II) tetrakis(isothiocyanato-κN)zinc(II), [Zn(CH4N2O)4(H2O)2][Zn(NCS)4], (II), were synthesized and studied by UV-Vis, fluorescence and IR spectroscopy. Coordination salt (II) forms a rare system composed of two different coordination units of the same metal and it is the first example of a compound with two completely different zinc coordination units, of which one contains a tetrakis(urea)zinc unit. Both (I) and (II) possess fluorescence properties and produce blue and green emissions, respectively, upon irradiation with violet light. The spectral properties were correlated with the observed molecular and supramolecular structures. The acetone thiosemicarbazone ligand of (I) exhibits (upon coordination) red shifts of bands corresponding to N=C and C=S stretching vibration frequencies, which is not typical for chelating molecules.

A (salicylaldiminato)Pt(II) complex with dimethylpropylene linkage: Synthesis, structural characterization and antineoplastic activity.

A novel (salicylaldiminato)Pt(II) complex with two different molecular structures, one solventless ((salicylaldiminato)Pt(II)) 1 and another one solvated ((salicylaldiminato)Pt(II). C2H5OH), 1·C2H5OH, has been obtained by the reaction of a salen ligand with [PtCl2(DMSO)2] in ethanol at room temperature. The asymmetric unit of solventless 1 contains 9 such complex molecules whereas 1·C2H5OH contains 2 complex molecules and one ethanol molecule. To get insights into the structure and bonding, DFT and TDFT calculation have been carried out. The electronic transition band at 408.0nm (calc. 424.3nm) is assigned to HOMO→LUMO (96%) excitation. The calculated NMR chemical shifts are interrelated with the experimental results, and a very slight effect of solvent was noticed on NMR chemical shifts. A MTT assay and the real-time cell monitoring xCELLigence system revealed that the 1 has significant potential to suppress cell viability and cell proliferation in human HT-29 and SW620 colorectal cancer cell lines.