Mononuclear Platinum Complexes Research Articles

Synthesis, structure, and mechanism of action of a unique mixed-ligand nickel (II)-complex of tetra-dentate phenol-based ligand with di-aquo co-ligands with significant pro-apoptotic and anti-metastatic effect against malignant human cancer cells

From the discovery of the anticancer activity of “cisplatin”, various type of numerous mononuclear platinum (II) complexes has been evaluated for antitumor activities, though therapeutic use is limited due to side effects and resistance. In this study, A unique mixed ligand mono nuclear octahedral Ni (II) complex [NiL(H2O)2].0·.5H2O (1) [H2L = N,Nʹ-dimethyl-N,Nʹ-bis (2-hydroxy-3,5-di methyl benzyl)-ethylenediamine] with tetra dentate phenol based ligand with N2O2 donor environment along with two labile water molecules was synthesised. The complex (1) is structurally characterized by spectroscopic tools including single-crystal X-ray diffractometer. Complex (1) crystallizes in monoclinic space group P21/n with a = 10.4871(17) Å, b = 20.860 (4) Å and c = 20.955(4) Å. The UV – visible spectra show two peaks around 507 nm and 367 nm due to spin-allowed 1A1g → 1A2g and 1A1g → 1B1g transitions respectively as expected for a square planar d8 system. Mixed ligand octahedral nickel (II) complex with facially coordinating tetra dentate phenol-based ligand (H2L) is in association with two water molecule as ancillary ligand. Two water molecules associated with coordination zone of nickel (II) centre is loosely bound. In this present study, we have evaluated the anti-cancer properties of Complex (1). We found that Complex (1) show potent cancer cell killing activity in case of poorly invasive mice and human cancer cell lines. Complex (1) trigger apoptosis chiefly via p53 dependent pathway. Complex (1) also inhibits cancer cell migration and epithelial to mesenchymal transition in case of metastatic breast cancer cells suggesting potent anti-cancer properties of complex (1).

A novel benzothiazole-based mononuclear platinum(II) complex displaying potent antiproliferative activity in HepG-2 cells via mitochondrial-mediated apoptosis

A novel mononuclear platinum(II) complex, [Pt(L-H)Cl] (1, where L= N-(4-(benzo[d]thiazol-2-yl)phenyl)-2-((2-pyridylmethyl)(2-hydroxyethyl)-amino)acetamide), was obtained by covalently tethering a benzothiazole derivative 2-(4-aminophenyl)benzothiazole to the 2-pyridylmethyl-2-hydroxyethylamine chelating PtII center. In vitro tests indicated that complex 1 displayed excellent antiproliferative activity against the tested cancer cell lines, especially liver cancer HepG-2 and SMMC-7221 cells. Importantly, the complex possessed 4.33-fold higher antiproliferative activity as compared with cisplatin against HepG-2 cells, but was less toxic to the normal cell line L02 with the selectivity index (SI = IC50(L02)/IC50(HepG-2)) value of 8.36 compared to cisplatin (SI, 1.40). The results suggested that 1 might have the potential to act as a candidate for the treatment of hepatocellular carcinoma (HCC). Cellular uptake and distribution studies showed that 1 could effectively pass through the membrane of cells, enter the nuclei and mitochondria, induce the platination of cellular DNA. The interaction of 1 with CT-DNA demonstrated that 1 could effectively bind to DNA in a dual binding mode, i.e., the intercalation of the 2-(4-aminophenyl)benzothiazole unit plus monofunctional platination of the platinum(II) moiety. In addition, Hoechst 33342 staining and flow cytometry analysis illustrated that 1 arrested the cell cycle in HepG-2 cancer cells at G2/M phases, induced mitochondrial membrane depolarization, increased ROS generation, and caused obvious cell apoptosis. Further cellular mechanism studies elucidated that 1 triggered HepG-2 cell apoptosis via the mitochondrial-mediated pathway by upregulating the gene and protein expression levels of Bax, downregulating the gene and protein expression levels of Bcl-2, and activating the caspase cascade.

Discrete Mononuclear Platinum(II) Complexes Realize High-Performance Red Phosphorescent OLEDs with EQEs of up to 31.8% and Superb Device Stability.

Designing mononuclear platinum(II) complexes that do not rely on intermolecular aggregation for high-performance red organic light-emitting diodes remains a formidable challenge. In this work, three robust red-emitting Pt(II) complexes w ere created by utilizing a rigid 4-coordination configuration, where the ligands w ere formed by linking electron-donor of triphenylamine (TPA) moieties with electron-acceptor of pyridine, isoquinoline, and/or δ-carboline units. The thermal stability, electrochemical, and photophysical properties of the complexes w ere thoroughly examined. The complexes display efficient red phosphorescence, with high photoluminescence quantum yields and short excited lifetimes. The OLEDs doped with these complexes exhibit high maximum external quantum efficiencies (EQEs) of up to 31.8% with minimal efficiency roll-off even at high brightness. Significantly, the devices demonstrated exceptional long operational lifetime, with a T90 lifetime of over 14000 hours at initial luminance of 1000cd m-2 , indicating the potential for these complexes to be practically utilized. This article is protected by copyright. All rights reserved.

In-vitro cytotoxic activity and theoretical investigations for new mononuclear Pt(IV) and dinuclear Ru(III) with o-phenylenediamine ligand complexes against L20B cell line

New mononuclear platinum(IV) and dinuclear ruthenium(III) complexes were synthesized with the o-phenylenediamine (OPD) ligand. The complexes were characterized by different spectroscopic techniques, and DFT calculations and their cytotoxic activity has been investigated in this study. The obtained FT-IR data confirmed that the o-phenylenediamine (OPD) ligand coordinated from the two nitrogen atoms with the platinum(IV) and the Ru(III) metal ions. The mass spectral data confirmed that the platinum(IV) complex was mononuclear, whereas the Ru(III) complex was dinuclear. The magnetic susceptibility measurements indicated that the platinum(IV) complex was diamagnetic, while Ru(III) complex was paramagnetic. UV–vis. measurements showed the peaks of the charge transfer and the (d-d) metal transitions. The DFT and TD-DFT calculations showed that the complexes were stable and the electronic energies are (-521.99 and − 963.59 a.u.) for the Pt(IV) and the Ru(III); respectively, while for the o-phenylenediamine ligand is (-342.96 a.u.), the HOMO energies are (-0.214 a.u.) for the Pt(IV) complex, and (-0.267 a.u.) for the Ru(III) complex, the LUMO energies are (-0.145 a.u.) for the Pt(IV) complex and (-0.183 a.u.) for the Ru(III) complex. The dipoles moment of the complexes are (13.70 and 0.004 Debye); respectively indicating that the complexes are polarized. From all the spectroscopic data, and the bond angles excluded from the DFT calculations the proposed structures of the complexes are distorted octahedral. The prepared complexes' cytotoxicity has been studied and the results showed that the Pt(IV) and the Ru(III) complexes have good cytotoxicity against L20B cell lines with IC50 (169.8 and 204.8 µg); respectively which opens the field for further application as antitumor complexes.

Hydrophilic platinum(II) complexes containing 5,7-dimethyl-1,2,4-triazolo[1,5-a]pyrimidine: Spectroscopic and in vitro cytotoxic characterization

Mononuclear platinum(II) complexes with 5,7-methyl-1,2,4-triazolo[1,5-a]pyrimidine (dmtp) of the general formula cis-[Pt(X)2(dmtp)2], where X - acetate (1), trichloroacetate (2), trifluoroacetate (3), nitrate (4) have been synthesized and characterized by multinuclear magnetic resonance (1H, 13C, 15N, 195Pt) and infrared spectroscopy methods. Spectroscopic parameters indicated the presence of the PtO2N2 chromophore system with two monodentate N(3)-bonded 5,7-methyl-1,2,4-triazolo[1,5-a]pyrimidines, and two monodentate O-donor ligands (carboxylate or nitrate).A cytotoxicity assay of hydrophilic platinum(II) complexes (1–4) against three human tumour cell lines A549 (non-small cell lung carcinoma), T47D (breast cancer), HT-29 (colon adenocarcinoma), and normal murine embryonic fibroblast cells (BALB/3T3) was performed.Considering the cytotoxic parameters of the studied complexes, the best in vitro results against the human breast tumour cells (T47D) were found for cis-[Pt(OOCCCl3)2(dmtp)2] although all the tested complexes (except complex (4)) exhibited moderate in vitro activity.

Organic Photoelectric Materials and Organic Photoelectric Devices Based on Smart Image Sensors

With the development of the times in recent years, people’s requirements for vision are no longer limited to the original foundation. As the core of research in this field, organic electroluminescence has paid great attention to the research points in the application of organic optoelectronic materials and devices in the world. From the relevant scientific research results in recent years, for example, organic light-emitting diodes can be used in flat-panel displays and solid-state lighting, organic photovoltaic cells can be used as a clean and renewable energy source to effectively alleviate the current energy needs of society, and organic storage, sensors, and so on show great promise for application. It can be seen that the research of organic optoelectronic materials and their devices will be the core hot spot of future new energy research. In the past, traditional organic optoelectronic materials are updated through the regulation strategy of covalent modification of the molecular structure. In recent years, new effective methods have been obtained to regulate the properties of excited states through physical stimulation (such as mechanical force, temperature, electric field, and magnetic field). The type of research experiment in this paper is based on the current hot smart image sensor, with the addition of organic complexes of mononuclear metal platinum and iridium metal and the organic optoelectronic device in the form of host and guest doping. The experimental results show that using PVK without energy transfer, polyvinyl carbazole (PVK) had been widely used as blue luminescent material and hole transport layer in electroluminescent device research. Simple mononuclear platinum and iridium metal complexes cannot obtain white light. For OPV devices, by selecting the correct solvent to control the bulk heterojunction, it exhibits better photovoltaic performance. Solvents play an important role in phase separation. In organic solar cells (OPV) consisting of an electron donor (D) and an acceptor (A), optimizing the D-A interface produces efficient charge separation, effectively separating excitons at the D-A interface and forming continuous electron and hole transport channels, and effective charge transport between electrodes plays a positive role.

Platinum (II) and palladium (II) complexes: synthesis, antimicrobial and antifungal activity

The study aims to synthesize and examine the biological activity of mono- and binuclear platinum (II) and palladium (II) complexes containing terminal and bridging nitrite ligands against the test cultures of Bacillus subtilis B4647, Aspergillus brasiliensis (niger) F679, Pseudomonas aeruginosa B8243, and Escherichia coli. Through the interaction of mononuclear platinum (II) and palladium (II) complexes, dimeric complexes having nitrite ligands were synthesized. The composition and structure of these complexes were established using elemental analysis, conductometry, potentiometry, cryoscopy, infrared spectroscopy, X-ray diffraction analysis, and X-ray fluorescence analysis. A way to coordinate nitrite ligands with the central atom was established. Antimicrobial and antifungal properties were evaluated according to the capability of the synthesized complexes to inhibit the activity of bacteria and fungi via diffusion in agar and in vitro dilution. The minimum inhibitory and bactericidal concentrations of the complexes suppressing the visible growth of microorganisms and fungi, as well as exhibiting their bactericidal effect, ranged from 62.5–125 μmol/dm3. The obtained results revealed a high activity of the palladium (II) binuclear complex of the non-electrolytic type and the platinum (II) binuclear complex of the cationic type. Unlike mononuclear complexes, palladium and platinum binuclear complexes demonstrate higher antibacterial activity. Antibacterial effectiveness exhibited by the palladium complex of the non-electrolytic type against bacteria Bacillus subtilis and Escherichia coli, as well as fungi Aspergillus niger, is more pronounced. The only exception is the antimicrobial activity of the palladium complex against Pseudomonas aeruginosa, which is comparable to that of the binuclear platinum complex of the cationic type. By changing the structure of the complex, the composition and charge of the inner sphere, the number of coordination centers, as well as the nature and denticity of ligands, it is possible to achieve a higher toxic effect of the complexes against bacteria and fungi.

NMR investigations on a series of diplatinum(II) complexes possessing phenylpropenoids in CDCl3 and CD3CN: Crystal structure of a mononuclear platinum complex

The NMR spectra of five diplatinum(II) complexes, Pt(μ-Cl)(arylolefin)]2 [arylolefin = Eug (1), iPrEug (2), Meug (3), EtEug (4), Saf (5)], in CDCl3 are studied. All the five complexes are formed by the reaction of K[PtCl3(arylolefinH)] with Ag2O in the mixture of alcohol-water. A mononuclear platinum complex, PtCl(Saf)(CH3CN)], which is formed by the crystallization of a dimeric complex 5 in acetonitrile is also investiated. The mononuclear platinum complex is characterized by elemental analysis, ESI mass spectrometry, infrared and NMR spectroscopic studies and single crystal X-ray crystallography. The single X-ray crystal structure reveals the coordination of Pt(II) ion to Saf via C = Callyl and the carbon of the benzene ring. DFT calculations are also performed to collect information about the structural parameter and stability of mononuclear platinum complexes. The findings reveal that the theoretical data agree with the experimental findings of single crystal X-ray structure. In addition, Hirshfeld surface analysis is also carried out to investigate various intermolecular interactions in the crystal structure of mononuclear platinum complex.

The non-templating synthesis of macro-cyclic Schiff base ligands containing pyrrole and homopiperazine and their binuclear nickel(II), cobalt(II) and mononuclear platinum(II) complexes: X-ray single crystal and anticancer studies

A new dialdehyde N, N'-bis(5-formylpyrrol-2-ylmethyl) homopiperazine (A) was synthesized by the Mannich reaction of pyrrole 2-carbaldehyde, formaldehyde and homopiperazine in the presence of hydrochloric acid. From the direct reaction of A with 1,3-diaminopropane or 1,4- diaminobutane two new macrocyclic Schiff base ligands were obtained, L1 and L2, respectively. The reaction of these ligands with Ni(II), Co(II) and Pt(II) metal ions results in formation of the relevant macrocyclic Schiff base complexes. Compounds were characterized by FT-IR, elemental analysis, mass spectrometry, UV-Vis and, in the case of the ligands, by 1H and 13C-NMR. The crystal structure of the complex [Ni2L2(CH3O)]ClO4 (4) showed a binuclear macro-cyclic structure, with each Ni coordinated by three nitrogen atoms from the ligand and by a methoxide bridging the two metal centers. The cytotoxic activities of these compounds indicated that the ligands, and some of the complexes, have high anti-proliferative effect towards A549 and HeLa cells, but not HT29 cells. Pt complex with L1 and L2 displayed stronger anti-proliferative activity toward HeLa (IC50 = 11 µM for both of them and A549 IC50 = 7 µM and 8 µM, respectively) relative to L1 and L2. In addition, the cytotoxic effects of the compounds were assayed in rat fibroblast cells as a model of the normal cell, however none of them showed any significant cytotoxic effects. Thereby upholding the potential of these compounds for further development as chemotherapeutic agents.

Biological properties of a benzothiazole-based mononuclear platinum(II) complex as a potential anticancer agent

A mononuclear platinum(II) complex, [PtLCl]Cl (1, where L = N-(4-(benzo[d]thiazol-2-yl)phenyl)-2-(bis(pyridine-2-ylmethyl)-amino)acetamide), was synthesized by covalently tethering a benzothiazole derivative 2-(4-aminophenyl)benzothiazole to the 2,2′-dipicolylamine (DPA) chelating PtII center by an amidic bond. 1 showed a cytotoxicity comparable to that of cisplatin against MCF-7 cell lines and more potent activities against HeLa and A-549 cell lines. Investigation of the reaction of 1 with 5′-GMP displayed 1 could coordinate with N7-GMP to form the Pt-GMP adduct. Thus 1 has potential to form Pt-DNA adducts in vivo. Similarly, the glutathione (GSH) ligand could also coordinate to the PtII center to form a monodentate Pt-GS complex. The competition experiments of 1 with 5′-GMP and GSH showed that the coordination binding of 1 with GSH did not prevent formation of a certain amount of the Pt-GMP adduct in the reaction process. DNA binding experiments displayed that 1 could bind to DNA through multiple binding modes involving non-covalent interaction and monofunctional platination of the platinum(II) moiety, and induce a visible conformational change of DNA. The evaluation of the protein binding ability showed that 1 could bind to human serum albumin (HSA) with a moderate binding affinity, quench the intrinsic fluorescence of HSA, and destroy the tertiary structure of HSA.

A luminescent europium hairpin for DNA photosensing in the visible, based on trimetallic bis-intercalators

Luminescence monitoring of DNA intercalator complexes is important for assessing their localisation and targeting: We report herein a luminescent hetero-trimetallic complex with europium as a luminescent reporter and two attached platinum acetylide terpyridyl units as the DNA recognition units. The ligand, based on a bisamide derivative of diethylenetriaminepentaacetic acid functionalized with two ethynyl groups, provides a backbone to anchor two platinum terpyridyl units, Pt-tpy, leading to the hairpin-shaped heterometallic complex 1. We also prepared a related mono-nuclear platinum complex 2 to compare its intercalation properties with 1. Linear dichroism, UV–visible and melting experiments show the ability of both complexes to interact with calf thymus DNA, with linear dichroism confirming intercalation and demonstrating the expected greater DNA stiffening by the bis-intercalator 1. Importantly, the tri-metallic complex 1 shows a three-fold enhancement in europium luminescence upon addition of calf thymus DNA; other mono-intercalator lanthanide designs have commonly shown a decrease in emission on binding. The ability of the complex to monitor DNA interactions gives the potential use as a luminescence switch in sensing experiments and highlights the design of heterometallic bis-intercalator complexes as an effective approach for DNA-responsive sensitisation of a lanthanide luminescence signal.

Induction of a Four‐Way Junction Structure in the DNA Palindromic Hexanucleotide 5′‐d(CGTACG)‐3′ by a Mononuclear Platinum Complex

AbstractFour‐way junctions (4WJs) are supramolecular DNA assemblies comprising four interacting DNA strands that in biology are involved in DNA‐damage repair. In this study, a new mononuclear platinum(II) complex 1 was prepared that is capable of driving the crystallization of the DNA oligomer 5′‐d(CGTACG)‐3′ specifically into a 4WJ‐like motif. In the crystal structure of the 1–CGTACG adduct, the distorted‐square‐planar platinum complex binds to the core of the 4WJ‐like motif through π–π stacking and hydrogen bonding, without forming any platinum–nitrogen coordination bonds. Our observations suggest that the specific molecular properties of the metal complex are crucially responsible for triggering the selective assembly of this peculiar DNA superstructure.

Induction of a Four-Way Junction Structure in the DNA Palindromic Hexanucleotide 5'-d(CGTACG)-3' by a Mononuclear Platinum Complex.

Four‐way junctions (4WJs) are supramolecular DNA assemblies comprising four interacting DNA strands that in biology are involved in DNA‐damage repair. In this study, a new mononuclear platinum(II) complex 1 was prepared that is capable of driving the crystallization of the DNA oligomer 5′‐d(CGTACG)‐3′ specifically into a 4WJ‐like motif. In the crystal structure of the 1–CGTACG adduct, the distorted‐square‐planar platinum complex binds to the core of the 4WJ‐like motif through π–π stacking and hydrogen bonding, without forming any platinum–nitrogen coordination bonds. Our observations suggest that the specific molecular properties of the metal complex are crucially responsible for triggering the selective assembly of this peculiar DNA superstructure.

Structural and biological evaluation of a platinum complex as a potential anti-neurodegenerative agent

A novel mononuclear platinum complex with N2O2 donor atoms was synthesized from the ligand, [N,N′-bis(3-methoxysalicylidene)-2,2-dimethylpropane-1,3-diamine], H2L. The complex was characterized by microanalysis (C, H, N), spectroscopic studies and single crystal X-ray crystallography. The TGA study revealed that the complex degraded in two distinct steps. The effect of the platinum complex was examined by exposing the synthesized complex to rat embryonic hippocampal neurons. The results exhibited significant neuritogenesis at low doses, suggesting it to be a potential therapeutic candidate for combating the neurodegenerative diseases.

Modulating the antitumoral activity by the design of new platinum(II) compounds: Synthesis, characterization, DFT, ultrastructure and mechanistic studies

The synthesis, physico-chemical characterization, Density functional theory (DFT) calculation and cytotoxicity against five human tumoral cell lines (THP-1, U937, Molt-4, Colo205 and H460) of four new platinum(II) coordination compounds are reported, i.e. [Pt(HL1)Cl]·H2O (1), [Pt(HL2)Cl]·H2O (2), [Pt(HL3)Cl]·H2O (3) and [Pt(HL4)Cl]·H2O (4). The ligands contain N2O donor sets. Furthermore, H2L3 and H2L4 present α and β-naphthyl groups respectively, which are absent in HL1 and H2L2. X-ray diffraction studies were performed for complex (3), indicating the formation of a mononuclear platinum(II) complex. Complexes (3) and (4), which contain α and β-naphthyl groups respectively, have presented lower IC50 (inhibitory concentration) values than those exhibited by complexes (1) and (2). The mechanism of cell death promoted by complexes (3) and (4) was investigated, suggesting that, toward U937 cell line, the α isomer promotes death by apoptosis and the β isomer by necrosis. Transmission and scanning electron microscopy investigations are in agreement with the loss of mitochondrial membrane potential (ΔΨm) observed by JC-1 mitochondrial potential sensor and indicate that the activity of complex (3) against U937 cell line is mediated by an apoptotic mechanism associated with mitochondrial dysfunction. A quantification of caspases 3, 6, 8 and 9 indicated that both the intrinsic and extrinsic pathways are involved in the apoptotic stimuli. Based on DFT calculations all the Pt(II) complexes present the same coordination environment for the metal centre, indicating that the higher cytotoxic activities exhibited by complexes (3) and (4) are related to the presence of the α and β-naphthyl groups in the ligand structure.

Novel dinuclear cyclometalated Platinum(II) complex as orange phosphorescent emitters for single-emitting-layer white polymer light-emitting diodes

Novel binuclear platinum complex (FPT)2Pt2(diPic) and mononuclear platinum complex (FPT)Pt(Pic) were designed and synthesized, where FPT is N-(4-(6-(9,9-diethyl-9H-fluoren-2-yl)pyridin-3-yl)phenyl)N-phenylbenzenamine, diPic is 3-(6-(2-carboxypyridin-3-yloxy)hexyloxy)picolinic acid, and Pic is picolinic acid. The photophysical, electrochemical and thermal properties, as well as electroluminescent (EL) properties for both platinum(II) complexes were studied. Compared to (FPT)Pt(Pic), (FPT)2Pt2(diPic) exhibited stronger phosphorescent emission in PL spectra and higher ΦPL, owing to the enhanced spin-orbit interaction of platinum centers. Moreover, the monochromatic devices based on (FPT)2Pt2(diPic) showed better EL properties than (FPT)Pt(Pic). Based on that, the single-emissive-layer WPLEDs using (FPT)2Pt2(diPic) as orange emitter and FIrpic as blue emitter were also obtained. The WPLEDs show best performances with a maximal LE of 1.3 cd/A, and a CIE coordinates of (0.35, 0.37) which is very close to the pure white emission. Work is still underway to improve the device efficiency and color purity of these iridium and platinum complexes co-doped WPLEDs.

Design and synthesis of novel organometallic complexes using boronated phenylalanine derivatives as potential anticancer agents

Drug design and discovery studies are important because of the prevalence of diseases without available medical cures. New anticancer agents are particularly urgent because of the high mortality rate associated with cancer. A series of mononuclear gold (III) and platinum (II) complexes based on boronated phenylalanine (BPA) were designed and synthesized using 4,4’-dimethyl-2,2’-dipyridyl (L1) or 1,10-phenanthroline-5,6-dion (L2) ligands to obtain promising anticancer drug candidates. Proton nuclear magnetic resonance, infrared, mass spectrometry, and elemental analyses were utilized for chemical characterizations. Cell viability, cancer cell colony formation, endothelial tube formation, and cytoskeleton staining assays were performed using A549 lung adenocarcinoma and human umbilical vein endothelial cells (HUVECs) to investigate preliminary pharmacological activities. L1-based platinum (II) complex (BPA-L1-Pt) was the most promising complex, and has similar activity with the approved chemotherapy drug cis-platinum. Half maximal inhibitory concentration values for BPA-L1-Pt were 9.15 µM on A549s and 16.61 µM on HUVECs; the values for cis-platinum were 5.24 µM on A549s and 23.14 µM on HUVECs. Consequently, further synthesis studies should be performed to boost the cancer cell selectivity feature of BPA by varying metal and ligand types.

Evolution of 1, 3, 5-trisubstituted bipyrazole scaffold based platinum(II) complexes as a biological active agent

Square planar mononuclear platinum(II) complexes having general formula [Pt(Ln)Cl2], (where, Ln = L1–4) were synthesized with neutral bidentate heterocyclic 1,3,5-trisubstituted bipyrazole based ligands. The synthesized compounds were characterized by physicochemical method such as TGA, molar conductance, micro-elemental analysis and magnetic moment, and spectroscopic method such as, FT-IR, UV–vis, 1H NMR, 13C NMR and mass spectrometry. Biological applications of the compounds were carried out using in vitro brine shrimp lethality bioassay, in vitro antimicrobial study against five different pathogens, and cellular level cytotoxicity against Schizosaccharomyces pombe (S. Pombe) cells. Pt(II) complexes were tested for DNA interaction activities using electronic absorption titration, viscosity measurements study, fluorescence quenching technique and molecular docking assay. Binding constants (Kb) of ligands and complexes were observed in the range of 0.23–1.07 × 105 M−1 and 0.51–3.13 × 105 M−1, respectively. Pt(II) complexes (I–IV) display an excellent binding tendency to biomolecule (DNA) and possess comparatively high binding constant (Kb) values than the ligands. The DNA binding study indicate partial intercalative mode of binding in complex-DNA. The gel electrophoresis activity was carried out to examine DNA nuclease property of pUC19 plasmid DNA.

Synthesis, characterization and biological application of 5-quinoline 1,3,5-trisubstituted pyrazole based platinum(ii) complexes.

Square planar mononuclear platinum(ii) complexes were synthesized in the presence of neutral bidentate heterocyclic (5-quinoline 1,3,5-tri-substituted pyrazole scaffold) ligands and K2PtCl4 salt. The synthesized compounds were characterized by micro-elemental analysis, FT-IR, UV-vis, 1H NMR, 13C NMR, TGA, mass spectrometry and molar conductivity. Their biological activities were investigated by in vitro brine shrimp lethality bioassay, in vitro antimicrobial study against five different pathogens, in vivo cellular level cytotoxicity against Schizosaccharomyces pombe cells, and in vitro anti-proliferation assay. The binding constant Ksv, Kb, Ka values of the complexes were determined by DNA interaction studies. The gel electrophoresis assay was carried out to examine the effect of the complexes on the DNA nuclease of pUC19 plasmid DNA. The docking energies of the ligands (L1-L5 ) and complexes (I-V) were observed in the range of -265.14 to -284.33 kJ mol-1. The synthesized Pt(ii) complexes (I-V) were screened against the MCF-7 (human breast adenocarcinoma) and HCT-116 (human colon carcinoma) cancer cell lines.

Dinuclear platinum(ii) complex dominated by a zig-zag-type cyclometalated ligand: a new approach to realize high-efficiency near infrared emission

Two new zig-zag type di- and mono-nuclear platinum(ii) complexes of (BuPh-BDIQ)Pt2(dpm)2 and (BuPh-BDIQ)Ptdpm were synthesized and characterized by using a zig-zag type cyclometalating ligand BuPh-BDIQ.