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Abstract Nanomaterials are an emerging class of compounds with potential to advance technology for wastewater treatment. There are many toxic substances in industrial wastewater that are dangerous to the aquatic ecosystem and public health. These pollutants require the development of novel techniques to remove them from the environment. Iron oxide nanoparticles are being studied and develop as new technology to address the problem of environmental pollution due to their unique properties and effectiveness against different kind of pollutants. A variety of modified iron oxide nanoparticles have been developed through extensive research that mitigates the shortcomings of aggregation or oxidation and enhances their efficiency as novel remediator against environmental pollutants. In this review, we present synthetic approaches used for the preparation of iron oxide nanoparticles and their corresponding nanocomposites, along with the processes in which the materials are used as adsorbent/photocatalysts for environmental remediation. Applications explored includes adsorption of dyes, photocatalytic degradation of dyes, and adsorption of heavy metal ions. The use of iron oxides nanocomposite in real wastewater samples and recyclability of adsorbents and photocatalysts were also explored. Graphical Abstract

Abstract Ternary quantum dot metal organic framework (MOFs) composite sensor formulated as (ZnInSe2@[Cu(2‐HNA)2(H2O)]) with an enhanced electrochemical performance was synthesized from a copper(II) metal‐organic framework complex ([Cu(2‐HNA)2(H2O)]) and ZnInSe2 ternary quantum dot (TQDs). The compounds were characterized by Fourier transform infrared spectroscopy, Ultraviolet‐Visible spectroscopy, transmission electron microscopy, scanning electron microscopy, single crystal X‐ray crystallography, and photoluminescence. Molecular structure of the copper(II) complex revealed a distorted square pyramidal geometry with two molecules of 2‐hydroxy‐1‐naphthaldedyde at the basal planes as bidentate chelating ligands with a coordinated water molecule at the apical position. TEM micrographs revealed monodispersed composite with an average particle size of 3.2 nm. The composite and its precursors were used as ectrochemical sensor for the detection of bisphenol A, using cyclic voltammetry, differential pulse voltammetry, and electrochemical impedance spectroscopy. The composite modified on a gold electrode exhibited enhanced electrochemical performance in comparison to those of the MOFs and TQDs. The reaction process at the surface of the modified electrode with the composite is diffusion controlled with a limit of detection, and limit of quantitation of 4.70 nM and 14.26 nM over a concentration range of 10–50 nM (S/N=3). The gold modified composite electrode is stable and could serve as a model for the development of electrochemical sensor to determine BPA.

Abstract Electrochemical sensors based on self‐assembled monolayer (SAM) were synthesized using metal‐organic frameworks (MOFs), quantum dots (QDs) and their composite (QDs@MOFs) to modify gold electrode (AuE) that was used as electrochemical sensors for bisphenol A detection. The molecular layer was assembled on the surface of the gold electrode by adsorption and provide a highly flexible method to tailor the interfaces between analyte and the electrode. Single crystal X‐ray of the MOF revealed a six‐coordinate copper(II) ion that bidentately coordinate two molecules of p‐anisic acid and two molecules of 1H‐benzimidazole to form a distorted octahedral geometry around the copper(II) ion. Electrochemical studies revealed that under optimal conditions, the modified gold electrode sensors show excellent sensing of bisphenol A, however, QDs@MOFs modified electrode is the best sensor with the highest oxidation peak current of 8.43E‐05 μA and the lowest charge transfer resistance of 19.4 Ω within a wide concentration range of 0.1–1 μM and a limit of detection (LOD) of 0.252 μM. This could be attributed to the electrocatalytic activity of the composite (QDs@MOFs) modified sensor, and the synergistic effect of the MOFs and QDs in the composite. The LOD is comparable to other electrochemical methods of sensing BPA which indicates that QDs@MOFs modified gold electrode could be develop as sensor for BPA.

Photothermal therapy (PTT) and photodynamic therapy (PDT) are potential cancer treatment methods that are minimally invasive with high specificity for malignant cells. Emerging research has concentrated on the application of metal nanoparticles encapsulated in porphyrin and their derivatives to improve the efficacy of these treatments. Gold and silver nanoparticles have distinct optical properties and biocompatibility, which makes them efficient materials for PDT and PTT. Conjugation of these nanoparticles with porphyrin derivatives increases their light absorption and singlet oxygen generation that create a synergistic effect that increases phototoxicity against cancer cells. Porphyrin encapsulation with gold or silver nanoparticles improves their solubility, stability, and targeted tumor delivery. This paper provides comprehensive review on the design, functionalization, and uses of plasmonic silver and gold nanoparticles in biomedicine and how they can be conjugated with porphyrins for synergistic therapeutic effects. Furthermore, it investigates this dual-modal therapy’s potential advantages and disadvantages and offers perspectives for future prospects. The possibility of developing gold, silver, and porphyrin nanotechnology-enabled biomedicine for combination therapy is also examined.

The preparation of biochar capped magnetic nanoparticles as adsorbents for the removal of methylene blue (MB), bromophenol blue (BPB) and rhodamine B (RhB) dyes is reported. Morphological studies of the untreated magnetic biochar nanoadsorbent showed monodispersed particles of about 20 nm. Brunauer, Emmett and Teller (BET) analysis revealed surface area of 138.28 m2/g while saturation magnetization was 12.61 emu/g. The energy bandgap of pure magnetite was reduced from 4.03 to 2.70 eV after capping with biochar. Maximum adsorption capacity (Qo) of the dyes onto the magnetic biochar are 14.39, 16.47 and 2.65 mg/g for MB, RhB and BPB respectively. The Langmuir equation best interpreted the sorption of methylene blue while Freundlich equation was more suitable for the sorption of bromophenol blue and Rhodamine B dyes. FTIR spectra of the magnetic biochar nanoadsorbent after adsorption indicated that uptake of the organic dyes occurred through physisorption. Competitive adsorption studies indicate the sorption of methylene blue, and bromophenol blue dyes occurred in acidic medium in comparison to neutral and alkaline media. The result from the study also shows that ethanol is the best eluent for the desorption of the organic dyes and eluted about 70% of adsorbed dyes in the first run.

Abstract Acinetobacter baumannii is an infectious agent of global proportion and concern, partly due to its proficiency in development of antibiotic resistance phenotypes and biofilm formation. Dithiocarbamates (DTC) have been identified as possible alternatives to the current antimicrobials. We report here the evaluation of several DTC-metal complexes against A. baumannii planktonic cells and biofilms. Among the DTC-metal complexes and DTCs tested, ZnL1 (N-methyl-1-phenyldithiocarbamato-S,S′ Zn(II)), originally designed as an antitumor agent, is effective against biofilm forming A. baumannii. A MIC value of 12.5 µM, comparable to that of Gentamicin (5 µM) was measured for planktonic cells in tryptic soy broth. Spectroscopy, microscopy and biochemical analyses reveal cell membrane degradation and leakage after treatment with ZnL1. Bioelectrochemical analyses show that ZnL1 reduces biofilm formation and decreases extracellular respiration of pre-formed biofilms, as corroborated by microscopic analyses. Due to the affinity of Zn to cells and the metal chelating nature of L1 ligand, we hypothesize ZnL1 could alter metalloprotein functions in the membranes of A. baumannii cells, leading to altered redox balance. Results indicate that the DTC-Zn metal complex is an effective antimicrobial agent against early A. baumannii biofilms under laboratory conditions.

Emerging pollutants (EPs) are unchecked pollutants with inherent negative potentials present in the environment. There are heightened concerns about the availability and fate of these pollutants in the ecosystem because they cannot be removed by conventional wastewater treatment methods. Adsorption, a facile and scalable technique, is a method which can be used for the removal of emerging contaminants. Ketoprofen and benzophenone were used as representative EPs to investigate their sorption from aqueous solutions. Manganese ferrite biochar (MnFe2O4@BC) prepared via co-precipitation route was used as adsorbent. The MnFe2O4/biochar magnetic nanocomposite was octagonally shaped with an average particle size of 42.64 nm. The specific surface area (SBET) analysis revealed that the nanocomposite was mesoporous with a surface area of 197.64 m2/g. The maximum adsorption capacity (Qo) of ketoprofen and benzophenone was 8.09 and 7.02 mg/g at 20 °C. Thermodynamic investigation revealed that the uptake of ketoprofen was spontaneous while adsorption studies revealed that Langmuir and Freundlich isotherm fitted the adsorption data of ketoprofen and benzophenone. The positive heat of reaction shows that the adsorption process was endothermic. Fourier transform infrared (FTIR) data suggests that the uptake of adsorbates was by physisorption. The used nanocomposite could easily be recovered with water and reused while recyclability studies indicate the magnetic nanocomposites adsorbent could be reused up to five consecutive cycles.

Tin sulphide (SnS) nanoparticles were synthesized from five tin(II) dithiocarbamate single-source precursors. Powder X-ray diffraction patterns of the SnS nanoparticles revealed orthorhombic herzenbergite phase of tin sulphide. SEM images of the SnS nanoparticles showed rough, smooth, flaky agglomerates and irregular morphologies. The bandgap energy of the nanoparticles estimated from Tauc plots are in the range 2.27–2.71 eV. The as-prepared SnS nanoparticles were used as nanophotocatalysts for the degradation of brilliant green under visible light irradiation. The results showed that the as-prepared SnS nanoparticles are efficient photocatalysts for the degradation of brilliant green with the highest degradation efficiency of 93% for SnS4 after 120 min. The as-prepared SnS nanoparticles showed good photostability in the recyclability studies.

Octylamine (OTA), 1-dodecanethiol (DDT), and tri-n-octylphosphine (TOP) capped magnetite nanoparticles were prepared by co-precipitation method. Powder X-ray diffraction patterns confirmed inverse spinel crystalline phases for the as-prepared iron oxide nanoparticles. Transmission electron microscopic micrographs showed iron oxide nanoparticles with mean particle sizes of 2.1 nm for Fe3O4-OTA, 5.0 nm for Fe3O4-DDT, and 4.4 nm for Fe3O4-TOP. The energy bandgap of the iron oxide nanoparticles ranges from 2.25 eV to 2.76 eV. The iron oxide nanoparticles were used as photocatalysts for the degradation of methylene blue with an efficiency of 55.5%, 58.3%, and 66.7% for Fe3O4-OTA, Fe3O4-DDT, and Fe3O4-TOP, respectively, while for methyl orange the degradation efficiencies were 63.8%, 47.7%, and 74.1%, respectively. The results showed that tri-n-octylphosphine capped iron oxide nanoparticles are the most efficient iron oxide nano-photocatalysts for the degradation of both dyes. Scavenger studies show that electrons (e−) and hydroxy radicals (•OH) contribute significantly to the photocatalytic degradation reaction of both methylene blue and methyl orange using Fe3O4-TOP nanoparticles. The influence of the dye solution’s pH on the photocatalytic reaction reveals that a pH of 10 is the optimum for methylene blue degradation, whereas a pH of 2 is best for methyl orange photocatalytic degradation using the as-prepared iron oxide nano-photocatalyst. Recyclability studies revealed that the iron oxide photocatalysts can be recycled three times without losing their photocatalytic activity.

Five heteroleptic ruthenium(II) polypyridyl complexes [Ru(FL1)(dcbpy)(NCS)] (1), [Ru(FL2)(dcbpy)(NCS)] (2), [Ru(FL3)(dcbpy)(NCS)] (3), [Ru(FL1)(dcbpy)(NCS)] (4), and [Ru(FL5)(dcbpy)(NCS)] (5) (where FL1 = aniline dithiocarbamate, FL2 = p-anisidine dithiocarbamate, FL3 = p-toluidine dithiocarbamate, FL4 = dibenzyl dithiocarbamate, and FL5 = diphenyl dithiocarbamate, dcbpy =2, 2′-bipyridine-4,4′-dicarboxylic acid, NCS = ammonium thiocyanate) have been synthesized and characterized with melting point, FTIR, UV-Vis, photoluminescence, and NMR (1H and 13C NMR) techniques, while the electrochemical activities of the complexes were studied using cyclic voltammetry. The FTIR of the heteroleptic complexes showed successful coordination of the ligands to ruthenium(II) ion, while the UV-Vis confirmed six coordinate octahedral geometry of the complexes, and the photoluminescence gave the photophysical properties with high intensities indicating potentials for dye sensitization. The electrochemical activities of the ruthenium(II) complexes showed redox potentials which could enhance the dye-sensitizing abilities.

Bis(piperidinyldithiocarbamato)palladium(II) ([Pd(Pipdtc)2]), bis(1-phenylpiperazinyldithiocarbamato)palladium(II) [Pd(1-PhPzdtc)2], bis(phenyldithiocarbamato)palladium(II) ([Pd(Phdtc)2]) and bis(4-benzylpiperidinyl)palladium(II) ([Pd(4-BenzPipdtc)2]) were prepared and characterized by elemental analysis, spectroscopic techniques and single crystal X-ray crystallography. Molecular structures of the Pd(II) complexes revealed square planar PdS4 geometry in which each Pd(II) is coordinated to two chelating dithiocarbamato anions. [Pd(Pipdtc)2] and [Pd(1-PhPzdtc)2] crystallized in monoclinic P21/c space group while [Pd(Phdtc)2] and [Pd(4-BenzPipdtc)2] crystallized in triclinic P-1 space group. Cytotoxic studies of the dithiocarbamate ligands and corresponding Pd(II) dithiocarbamate complexes were tested against three human cell lines: Cervical cancer, breast adenocarcinoma, and epithelial colorectal adenocarcinoma at four different concentrations. All the compounds displayed high to moderate potency against the cell lines. [Pd(Pipdtc)2] and [Pd(Phdtc)2] are very potent against the three cell lines and are more active than the corresponding dithiocarbamate ligands whereas the anticancer potency of 1-PhPzdtc-Na and 4-BenzPipdtc-Na are generally higher than the corresponding Pd(II) complexes.

Molecular structures of 4-(((4-methoxyphenyl)amino)methyl)-N,N-dimethylaniline and 2-methoxy-5-((phenylamino)methyl)phenol synthesized via Schiff bases reduction route are reported. The compounds consist of asymmetric units of C16H20N2O (1) and C14H15NO2 (2) in orthorhombic and monoclinic crystal systems, respectively. Compound 1 consist of intermolecular C11—H11···N2 hydrogen bonding with C11···N21 = 3.463(4) Å. The hydroxyl group in 2 is also involved in intermolecular O2—H2···O2 and O2—H2···O21 hydrogen bonding with O2···O11 = 2.8885(15) Å and O1···O21 = 2.9277(5) Å. The molecular structures of the compounds are stabilized by secondary intermolecular interactions of C1—H1B···O11 and C5—H···(C41, C51, C61, C71) for 1 and H···C, C—H···O and N—H···C for 2. The reported compounds are important starting material for the synthesis of many compounds such as azo dyes and dithiocarbamate.

Abstract Adsorptive removal of organic pollutant (pyrene) was carried out using coordination polymer [Cu(Pic)2(H2O)2]·H2O (CP-1) (where “Pic” represents picolinic acid), which was prepared from copper acetate monohydrate and picolinic acid. The compound was characterized by spectroscopic techniques, SEM, elemental and thermal analyses and X-ray crystallographic analysis. The crystal structure of CP-1 shows a centrosymmetric triclinic space group P-1 in which a = 5.0924 (4) Å, b = 7.5172 (6) Å, c = 9.0965 (8) Å. The Cu2+ ion is seen to have an octahedral geometry, which is bonded to oxygen atoms from the picolinic acid and nitrogen atoms from the pyridine rings. Pyrene adsorption from aqueous media was studied with the prepared adsorbent (CP-1). The kinetic model was observed to be second order, and the sorption data fitted best into the Langmuir model. The absorbent, CP-1, was shown to have a 90.91 mg/g adsorption capacity (maximum) for pyrene in this study at 25 °C. Compound CP-1 can thus be presented as a potential adsorbent in the treatment of pyrene-polluted water.

Adsorption isotherms are indispensable tools for the description of sorption processes of pollutants on adsorbents. The closeness of the equilibrium concentration (qe) to the calculated solid phase concentration (qecal) of the adsorbate, together with the co-efficient of determination (R2) and associated errors are important in determining the best goodness-of-fit model. In this work we have investigated the adsorption of Pb(II) and Cr(VI) on a nanocomposite that was prepared using magnetite nanoparticles capped with locally prepared biochar and functionalized using 3-(aminopropyl) triethoxysilane (APTES) at 3 different temperatures. Detailed discussion of data can be found in DOI:10.1016/j.micromeso.2020.110573. The sorption processes were equally analyzed utilizing both the linear and non-linear forms of Langmuir, Freundlich and Temkin equations.

Activated carbon prepared from Zea mays stem using chemical activation was used as adsorbent for the removal of metal ions from aqueous solution. The results indicate that the adsorption of Pb(II), Cu(II) and Cr(III) ions is pH, contact time, and concentration dependent while the adsorption of Hg(II) is very different. The maximum removal percentages obtained at pH 5-6 were 97.44 % for Pb(II), 98.37 % for Cu(II), 89.37 % for Cr(III) and there was no adsorption for mercury ions. The metal ion removal trend follows the order Pb(II) > Cr(III) > Cu(II). The results show that Langmuir model fitted well in most cases with R2 > 0.99. Consequently, the adsorption of Pb(II) and Cu(II) followed Langmuir isotherm model while that of Cr(III) best fitted on Freundlich isotherm model.

We present the preparation of octadecylamine-capped ZnS quantum dots from bis(morpholinyldithiocarbamato)Zn(II) complex. The complex was thermolyzed at 130 °C in octadecylamine at different times, to study the effect of reaction time on the morphological and photocatalytic properties of the ZnS quantum dots. Powder X-ray diffraction patterns confirmed a hexagonal wurtzite crystalline phase of ZnS, while HRTEM images showed particle sizes of about 1–3 nm, and energy band gaps of 3.68 eV (ZnS–1), 3.87 eV (ZnS–2), and 4.16 eV (ZnS–3) were obtained from the Tauc plot for the ZnS nanoparticles. The as-prepared ZnS were used as photocatalysts for the degradation of brilliant green, rhodamine B, and binary dye consisting of a mixture of brilliant green-rhodamine B. The highest photocatalytic degradation efficiency of 94% was obtained from ZnS–3 with low photoluminescence intensity. The effect of catalytic dosage and pH of the dyes solution on the photocatalytic process shows that pH 8 is optimal for the degradation of brilliant green, while pH 6.5 is the best for photocatalytic degradation of rhodamine B. The degradation of the binary dyes followed the same trends. The effect of catalytic dosage shows that 1 mg mL−1 of the ZnS nano-photocatalyst is the optimum dosage for the degradation of organic dyes. Reusability studies show that the ZnS quantum dots can be reused five times without a significant reduction in degradation efficiency.

Bis(4-methylpiperidine-1-carbodithioato)-lead(II) and bis(4-benzylpiperidine-1-carbodithioato)-lead(II) were prepared and their molecular structures elucidated using single crystal X-ray crystallography and spectroscopic techniques. The compounds were used as precursors for the preparation of lead sulphide nano photocatalysts for the degradation of rhodamine B. The single crystal structures of the lead(II) dithiocarbamate complexes show mononuclear lead(II) compounds in which each lead(II) ion coordinates two dithiocarbamato anions in a distorted tetrahedral geometry. The compounds were thermolyzed at 180 ℃ in hexadecylamine (HDA), octadecylamine (ODA), and trioctylphosphine oxide (TOPO) to prepare HDA, ODA, and TOPO capped lead sulphide (PbS) nanoparticles. Powder X-ray diffraction (pXRD) patterns of the lead sulphide nanoparticles were indexed to the rock cubic salt crystalline phase of lead sulphide. The lead sulphide nanoparticles were used as photocatalysts for the degradation of rhodamine B with ODA-PbS1 achieving photodegradation efficiency of 45.28% after 360 min. The photostability and reusability studies of the as-prepared PbS nanoparticles were studied in four consecutive cycles, showing that the percentage degradation efficiency decreased slightly by about 0.51–1.93%. The results show that the as-prepared PbS nanoparticles are relatively photostable with a slight loss of photodegradation activities as the reusability cycles progress.

We report the effect of thermolysis time on the morphological and optical properties of CuS nanoparticles prepared from Cu(II) dithiocarbamate single-source precursor. The as-prepared copper sulfide nanoparticles were used as photocatalysts for the degradation of crystal violet (CV), methylene blue (MB), rhodamine B (RhB), and a ternary mixture of the three dyes (CV/MB/RhB). Powder XRD patterns confirmed the hexagonal covellite phase for the CuS nanoparticles. At the same time, HRTEM images revealed mixed shapes with a particle size of 31.47 nm for CuS1 prepared at 30 min while CuS2 prepared at 1 h consists of mixtures of hexagonal and nanorods shaped particles with an average size of 21.59 nm. Mixed hexagonal and spherically shaped particles with a size of 17.77 nm were obtained for CuS3 prepared at 2 h. The optical bandgaps of the nanoparticles are 3.00 eV for CuS1, 3.26 eV for CuS2 and 3.13 eV for CuS3. The photocatalytic degradation efficiency showed that CuS3 with the smallest particle size is the most efficient photocatalyst and degraded 85% of CV, 100% of MB, and 81% of RhB. The as-prepared CuS showed good stability and recyclability and also degraded ternary dyes mixture (CV/MB/RhB) effectively. The byproducts of the dye degradation were evaluated using ESI-mass spectrometry.

The demand for water is predicted to increase significantly over the coming decades; thus, there is a need to develop an inclusive wastewater decontaminator for the effective management and conservation of water. Magnetic oxide nanocomposites have great potentials as global and novel remediators for wastewater treatment, with robust environmental and economic gains. Environment-responsive nanocomposites would offer wide flexibility to harvest and utilize massive untapped natural energy sources to drive a green economy in tandem with the United Nations Sustainable Development Goals. Recent attempts to engineer smart magnetic oxide nanocomposites for wastewater treatment has been reported by several researchers. However, the magnetic properties of superparamagnetic nanocomposite materials and their adsorption properties nexus as fundamental to the design of recyclable nanomaterials are desirable for industrial application. The potentials of facile magnetic recovery, ease of functionalization, reusability, solar responsiveness, biocompatibility and ergonomic design promote the application of magnetic oxide nanocomposites in wastewater treatment. The review makes a holistic attempt to explore magnetic oxide nanocomposites for wastewater treatment; futuristic smart magnetic oxides as an elixir to global water scarcity is expounded. Desirable adsorption parameters and properties of magnetic oxides nanocomposites are explored while considering their fate in biological and environmental media.

Cu(II) and Zn(II) morpholinyldithiocarbamato complexes, formulated as [Cu(MphDTC)2] and [Zn(μ-MphDTC)2(MphDTC)2], where MphDTC is morpholinyldithiocarbamate were synthesized and characterized by elemental analysis, spectroscopic techniques and single-crystal X-ray crystallography. The molecular structure of the Cu(II) complex revealed a mononuclear compound in which the Cu(II) ion was bonded to two morpholinyl dithiocarbamate ligands to form a four-coordinate distorted square planar geometry. The molecular structure of the Zn(II) complex was revealed to be dinuclear, and each metal ion was bonded to two morpholinyl dithiocarbamate bidentate anions, one acting as chelating ligand, the other as a bridge between the two Zn(II) ions. The anticancer activity of the morpholinyldithiocarbamate ligand, Cu(II) and Zn(II) complexes were evaluated against renal (TK10), melanoma (UACC62) and breast (MCF7) cancer cells by a Sulforhodamine B (SRB) assay. Morpholinyldithiocarbamate was more active than the standard drug parthenolide against renal and breast cancer cell lines, and [Zn(μ-MphDTC)2(MphDTC)2] was the most active complex against breast cancer. The copper(II) complex had a comparable activity with the standard against renal and breast cancer cell lines but showed an enhanced potency against melanoma when compared to parthenolide.

The aim of this mini review was to report the molybdenum compound intervention to control cancer disease. The intervention explains its roles and progress from inorganic molybdenum compounds via organomolybdenum complexes to its nanoparticles to control oesophageal cancer and breast cancer as case studies. Main contributions of molybdenum compounds as anticancer agents could be observed in their nanofibrous support with suitable physicochemical properties, combination therapy, and biosensors (biomarkers). Recent areas in anticancer drug design, which entail the uses of selected targets, were also surveyed and proposed.

Progresses made in previous researches on syntheses of dithiocarbamates led to increase in further researches. This paper reviews concisely the challenges experienced during the synthesis of dithiocarbamate and mechanisms to overcome them in order to obtain accurate results. Aspects of its precursor’s uses to synthesize adducts, nanoparticles, and nanocomposites are reported. Some common characterization techniques used for the synthesized products were assessed. Biological applications are also reported.

SnS nanocrystals were synthesized using bis(phenylpiperazine dithiocarbamate)tin(II) in oleic acid (OA) and octadecylamine (ODA) at three different temperatures (150, 190, and 230°C). XRD diffraction pattern confirms that OASnS and ODASnS nanoparticles are in the orthorhombic phase and the type of capping agent used affects the crystallinity. Transmission electron microscopy (TEM) images shows spherically shaped nanocrystals for oleic acid capped SnS (OASnS) while octadecylamine (ODASnS) are cubic. Monodispersed SnS of size range 10.67–17.74 nm was obtained at 150°C for OASnS while the biggest-sized nanocrystals were obtained at 230°C for ODASnS. Temperature and capping agents tuned the crystallite sizes and shapes of the as-prepared nanocrystals. Electron dispersive X-ray spectroscopy indicates the formation of tin sulphide with the presence of Sn and S peaks in the nanocrystals. Flowery and agglomerated spherical-like morphology were observed for ODASnS and OASnS nanocrystals, respectively, using a SEM (scanning electron microscope). Direct electronic band gaps of the synthesized SnS nanocrystals are 1.71–1.95 eV and 1.93–2.81 eV for OASnS and ODASnS nanocrystals, respectively.

Platinum-group (PG) complexes have been used as antibacterial and anticancer agents since the discovery of cisplatin. The science world still requires improvement on these complexes because of multidrug and antineoplastic resistances. This review observes discoverers and history of these platinum-group metals (PGMs), as well as their beneficial applications. The focus of this study was biological applications of PGMs in relation to human health. Sandwich and half-sandwich PGM coordination compounds and their metal nanoparticles give improved results for biological activities by enhancing efficient delivery of both antibacterial and anticancer drugs, as well as luminescent bioimaging (biomarkers) for biological identifications.

We report the synthesis and structural studies of copper sulfide nanocrystals from copper(II) dithiocarbamate single molecule precursors. The optical studies of the as-prepared copper sulfide nanoparticles were carried out using UV–Visible and photoluminescence spectroscopy. The absorption spectra show absorption band edges at 287 nm and exhibit considerable blue shift that could be ascribed to the quantum confinement effects as a result of the small crystallite sizes of the nanoparticles and the photoluminescence spectra show emission curves that are red shifted with respect to the absorption band edges. The structural studies were carried out using powder X-ray diffraction, transmission electron microscopy, scanning electron microscopy, energy dispersive X-ray spectroscopy and atomic force microscopy. The XRD patterns revealed the formation of hexagonal structure of covellite CuS with estimated crystallite sizes of 17.3–18.6 nm. The TEM images showed particles with almost spherical or rod shapes with average crystallite sizes of 3–9.8 nm. SEM images showed morphology with ball-like microsphere on the surfaces and EDS spectra confirmed the presence of CuS nanoparticles. Keywords: CuS, Dithiocarbamate, Nanoparticles, Electron microscopy, AFM

Co(II), Ni(II), Zn(II) and Cu(II) complexes of (3E)-3-[(2-{(E)-[1-(2,4-dihydroxyphenyl)ethylidene]amino}ethyl)imino]-1-phenylbutan-1-one (DEPH2) derived from ethylenediamine, 2′,4′-dihydroxyacetophenone and 1-phenylbutane-1,3-dione have been synthesized and characterized by elemental analysis, FTIR, UV-Visible spectroscopy, and screened to establish their potential as antibacterial agents, antioxidants and DPPH radical scavengers. The FTIR spectra showed that the ligand behaves as a dibasic tetradentate ligand with the dioxygen-dinitrogen donor atom system oriented towards the central metal ion. The analytical and spectroscopic data suggest a square planar geometry for Cu(II) and Ni(II) complexes and an octahedral geometry for the Co(II) complex. The ligand and their metal complexes were screened for antibacterial activity against Gram (+) and Gram (−) bacteria by the agar well diffusion method. In addition, the antioxidant activities of the complexes were also investigated through their scavenging effect on DPPH and ABTS radicals. The obtained IC50 value of the DPPH activity for the copper complex (2.08 ± 0.47 µM) and that of the ABTS activity for the copper complex (IC50 = 2.11 + 1.69 µM) were higher than the values obtained for the other compounds.

The anticancer study of nitrogen-chelating ligands can be of tremendous help in choosing ligands for the anticancer metal complexes design especially with ruthenium(II). The inhibitory anticancer activities of some nitrogen-chelating ligands containing bis-pyrazole, bipyridine, and phenanthroline were studied using experimental screening against cancer cell and theoretical docking methods. In vitro anticancer activities showed compound 11 as the most promising inhibitor, and the computational docking further indicates its strong inhibitory activities towards some cancer-related receptors. Among the twenty-one modelled ligands, pyrazole-based compounds 7, 11, and 15 are the most promising inhibitors against the selected receptors followed by 18 and 21 which are derivatives of pyridine and phenanthroline, respectively. The presence of the carboxylic unit in the top five ligands that displayed stronger inhibitory activities against the selected receptors is an indication that the formation of noncovalent interactions such as hydrogen bonding and a strong electron-withdrawing group in these compounds are very important for their receptor interactions. The thermodynamic properties, the polarizabilities, and the LUMO energy of the compounds are in the same patterns as the observed inhibitory activities.

A number of novel ruthenium(II) polypyridine complexes have been designedand synthesized for use as photosensitizers in dye-sensitized solar cells (DSSCs) due totheir rich photophysical properties such as intense absorption, long-lived lifetimes, highemission quantum yields and unique redox characteristics. Many of these complexesexhibit photophysical behavior that can be readily controlled through a careful choice ofligands and/or substituents. With this perspective, we review the design and general syntheticmethods of some polypyridine ligands based on bipyridine, phenanthroline, terpyridine andquaterpyridine with/without anchoring groups with a view to correlate functionality ofligand structures with the observed photophysical, electroredox and power conversionefficiency of some examples of Ru(II) polypyridyl complexes that have been reported andparticularly used in the DSSCs applications. The main interest, however, is focused onshowing the development of new polypyridine ligand materials containing long-rangeelectron transfer motifs such as the alkenyl, alkynyl and polyaromatic donor functionalities.

Unlike organic molecules, reports on docking of metal complexes are very few; mainly due to the inadequacy of force fields in docking packages to appropriately characterize the metal atoms that consequentially hinder the rational design of metal-based drug complexes. In this study we have made used Molegro and Autodock to predict the anticancer activities of selected Ru(II) complexes against twelve anticancer targets. We observed that introducing the quantum calculated atomic charges of the optimized geometries significantly improved the docking predictions of these anticancer metallocompounds. Despite several limitations in the docking of metal-based complexes, we obtained results that are highly correlated with the available experimental results. Most of our newly proposed metallocompounds are found theoretically to be better anticancer metallocompounds than all the experimentally proposed RAPTA complexes. An interesting features of a strong interactions of new modeled of metallocompounds against the two base edges of DNA strands suggest similar mechanisms of anticancer activities similar to that of cisplatin. There is possibility of covalent bonding between the metal center of the metallocompounds and the residues of the receptors DNA-1, DNA-2, HDAC7, HIS and RNR. However, the general results suggest the possibility of metals positioning the coordinated ligands in the right position for optimal receptor interactions and synergistic effects, rather than forming covalent bonds.

In cancer chemotherapy, metal-based complexes have been recognized as the most promising means of inhibiting cancer growth due to the successful application of cis-platin and its derivatives above many of the existing organic anticancer agents. The limitations in their rational design can be traced to the complexity of the mechanism of their operations, lack of proper knowledge of their targets and lack of force fields in docking packages to appropriately define the metal centre of the organometallic complexes. In this paper, some of the promising anticancer complexes of Ru(II) such as the rapta-based complexes formulated as [Ru(η6-p-cymene)L2(pta)] and those with unusual ligands are considered. CatB and kinases which have been experimentally confirmed as possible targets of the complexes are also predicted by the three methods as one of the most targeted receptors while TopII and HDAC7 are predicted by two and one of the methods as best targets. The interesting features of the binding of the complexes show that some of the complexes preferentially target specific macromolecules than the others, which is an indication of their specificity and possibility of their therapeutic combination without severe side effects that may come from competition for the same target. Also, introduction of unusual ligands is found to significantly improve the activities of most of the complexes studied. Strong correlations are observed for the predicted binding sites and the orientation of the complexes within the binding site by the three methods of docking. However there are disparities in the ranking of the complexes by the three method of docking, especially that of Glide.

In our quest to develop good materials as photosensitizers for photovoltaic dye-sensitized solar cells (DSSCs), cis-dithiocyanato-4-(2,3-dimethylacrylic acid)-2,2'-bipyridyl-4-(9-anthracenyl-(2,3-dimethylacrylic)-2,2'-bipyridyl ruthenium(II) complex, a high molar extinction coefficient charge transfer sensitizer, was designed, synthesized and characterized by spectroscopy and electrochemical techniques. Earlier studies on heteroleptic ruthenium(II) complex analogues containing functionalized oligo-anthracenyl phenanthroline ligands have been reported and documented. Based on a general linear correlation between increase in the length of π-conjugation bond and the molar extinction coefficients, herein, we report the photophysical and electrochemical properties of a Ru(II) bipyridyl complex analogue with a single functionalized anthracenyl unit. Interestingly, the complex shows better broad and intense metal-to ligand charge transfer (MLCT) band absorption with higher molar extinction coefficient (λmax = 518 nm, e = 44900 M−1cm−1), and appreciable photoluminescence spanning the visible region than those containing higher anthracenyl units. It was shown that molar absorption coefficient of the complexes may not be solely depended on the extended π-conjugation but are reduced by molecular aggregation in the molecules.

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Two series of bidentate polypyridine ligands, made of phenanthroline chelating subunits having substituted mono-and di-anthracenyl groups, and 1-methoxy-1-buten-3-yne at the 4 and 7-positions with the corresponding heteroleptic Ru(II) complex have been synthesized and characterized. The complex is formulated as [(Ru(L1)(L2)(NCS)2)], (where L1 = 4-(9-dianthracenyl-10-(2,3-dimethylacrylic acid)-7-(9-anthracenyl-10-(2,3-dimethylacrylic acid)-1,10-phenanthroline and L2 = 4,7-bis(1-methoxy-1-buten-3-yne)-1,10-phenanthroline). The Ru(II) complex shows characteristic broad and intense metal-to-ligand charge transfer (MLCT) bands absorption and appreciable photoluminescence spanning the visible region. The ligands and complex were characterized by FT-IR, 1H, 13C NMR spectroscopy, UV-Vis, photoluminescence and elemental analysis (see in supplementary materials). The anchoring groups in both ligands have allowed an extended delocalization of acceptor orbital of the metal-to-ligand charge-transfer (MLCT) excited state.

Ni(II) dithiocarbamate complexes have been synthesized and characterized by UV-Vis, FTIR, and NMR spectroscopic techniques. Electronic spectra measurements indicate that the complexes are four-coordinate square planar geometry while the FTIR confirmed that the dithiocarbamates act as bidentate chelating ligands. The compounds were used as single source precursors and thermolysed at 220°C to prepare HDA-capped NiS nanocrystals which were characterized by absorption and photoluminescence (PL) spectra measurements, powder X-ray diffraction (PXRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), and energy dispersive spectroscopy (EDS). Absorption spectra studies showed that the synthesized NiS nanoparticles are blue-shifted relative to the bulk material and PL studies showed emission maxima that are red-shifted compared to the absorption band edges. The XRD patterns of the as-prepared NiS nanoparticles revealed cubic crystalline phases. TEM images showed spherical and close-to-spherical nanocrystals with the size in the range 12–38 nm for NiS1, 8–11 nm for NiS2, and 9–16 nm for NiS3. SEM images showed homogeneous surface morphology and EDS confirmed the presence of Ni and S and the formation of NiS nanoparticles.

We report some experimental bond distances and computational models of six ruthenium bonds obtained from DFT to higher computational methods like MP2 and CCSD. The bonds distances, geometrical RMSD, and the thermodynamic properties of the models from different computational methods are similar. It is observed that optimization of molecules of many light atoms with different functional methods results in significant geometrical variation in the values and order of the computed properties. The values of the hyperpolarizabilities, HOMO, LUMO, and isotropic and anisotropic shielding are found to depend greatly on the type of the functional used and the geometrical variation rather than on the nature of basis set used. However, all the methods rated modelled Ru-S, Ru-Cl, and Ru-O bonds as having the highest hyperpolarizabilities values. The infrared spectra data obtained from the different computational methods are significantly different from each other except for MP2 and CCSD which are found to be very similar.

Mononuclear Ru(III) complexes of the type [Ru(LL)Cl2(H2O)] (LL = monobasic tridentate Schiff base anion: (1Z)-N′-(2-{(E)-[1-(2,4-dihydroxyphenyl)ethylidene]amino}ethyl)-N-phenylethanimidamide [DAE], 4-[(1E)-N-{2-[(Z)-(4-hydroxy-3-methoxybenzylidene)amino]ethyl}ethanimidoyl]benzene-1,3-diol [HME], 4-[(1E)-N-{2-[(Z)-(3,4-dimethoxybenzylidene)amino]ethyl}ethanimidoyl]benzene-1,3-diol [MBE], and N-(2-{(E)-[1-(2,4-dihydroxyphenyl)ethylidene]amino}ethyl)benzenecarboximidoyl chloride [DEE]) were synthesized and characterized using the microanalytical, conductivity measurements, electronic spectra, and FTIR spectroscopy. IR spectral studies confirmed that the ligands act as tridentate chelate coordinating the metal ion through the azomethine nitrogen and phenolic oxygen atom. An octahedral geometry has been proposed for all Ru(III)-Schiff base complexes. In vitro anticancer studies of the synthesized complexes against renal cancer cells (TK-10), melanoma cancer cells (UACC-62), and breast cancer cells (MCF-7) was investigated using the Sulforhodamine B assay. [Ru(DAE)Cl2(H2O)] showed the highest activity with IC50 valves of 3.57±1.09, 6.44±0.38, and 9.06±1.18 μM against MCF-7, UACC-62, and TK-10, respectively, order of activity being TK-10 < UACC-62 < MCF-7. The antioxidant activity by DPPH and ABTS inhibition assay was also examined. Scavenging ability of the complexes on DPPH radical can be ranked in the following order: [Ru(DEE)Cl2(H2O)] > [Ru(HME)Cl2(H2O)] > [Ru(DAE)Cl2(H2O)] > [Ru(MBE)Cl2(H2O)].

Co(II), Ni(II), Cu(II), and Zn(II) complexes of (4E)-4-[(2-{(E)-[1-(2,4-dihydroxyphenyl)ethylidene]amino}ethyl)imino]pentan-2-one have been synthesized and characterized by elemental analyses, molar conductance, electronic and IR spectral studies, and XRD. FTIR confirmed the ligand coordinates the metal ion to form mononuclear complex via the oxygen and nitrogen atoms of the phenolic group and azomethine group, respectively. Tetrahedral geometry is proposed for Co(II) complex and square-planar geometry for Ni(II) and Cu(II) complexes. The antibacterial studies of the compounds were determined and they show that the metal complexes are more active than the free ligands. The antioxidant activity by DPPH and ABTS method was examined and it shows Cu(II); IC50 = 2.31 ± 1.54 µM for DPPH and Co(II); IC50 = 1.83 ± 1.08 µM for ABTS were the most active.

The changes in the interatomic distances and the corresponding spin-spin coupling as a result of the hydrolysis of the ruthenium complexes and the effects of different derivatives of the pyrazole ligands and the substituents methyl, carboxylic, and phenyl on the pyrazole rings were studied. A good agreement was obtained between the experimental and the theoretical proton NMR. Significant changes are observed in the isotropic and anisotropic shielding tensor of the atoms and related spin-spin coupling of their bonds due to hydrolysis of the complexes. This observation gives more insight into the known mechanism of activation of the ruthenium complexes by hydrolysis. There are no direct effects of interatomic distances on many of the computed spin-spin couplings with the exception of 1J(Ru-N) which shows significant changes especially within the pair of 1J(Ru-N) in the complexes with two nitrogen atoms of the bis-pyrazole moiety. The magnitude of interatomic spin-spin coupling of the Ru-X follows the order of Ru-Cl > Ru-N > Ru-C > Ru-O. The Ramsey term Fermi contact (FC) has the most significant contribution in most of the computed spin-spin interactions except in 1J(Ru-Cl) and 1J(N-N⁎) which are predominantly defined by the contribution from the paramagnetic spin orbit (PSO).

We report the synthesis and structural studies of copper sulfide nanocrystals from copper (II) dithiocarbamate single molecule precursors. The precursors were thermolysed in hexadecylamine (HDA) to prepare HDA-capped CuS nanocrystals. The optical properties of the nanocrystals studied using UV–visible and photoluminescence spectroscopy showed absorption band edges at 287 nm that are blue shifted, and the photoluminescence spectra show emission curves that are red-shifted with respect to the absorption band edges. These shifts are as a result of the small crystallite sizes of the nanoparticles leading to quantum size effects. The structural studies were carried out using powder X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), and atomic force microscopy. The XRD patterns indicates that the CuS nanocrystals are in hexagonal covellite crystalline phases with estimated particles sizes of 17.3–18.6 nm. The TEM images showed particles with almost spherical or rod shapes, with average crystallite sizes of 3–9.8 nm. SEM images showed morphology with ball-like microspheres on the surfaces, and EDS spectra confirmed the presence of CuS nanoparticles.

New heteroleptic ruthenium(II) complex was formulated as [Ru(L1)2(NCS)2], where L1 = 9-anthracenyl-10-(2-methyl-2-butenoic acid)-1,10-phenanthroline was synthesized and its photophysical properties were studied and compared to previously reported analogue complex containing no anthracene moiety [Ru(L2)2(NCS)2], L2 = (2-methyl-2-butenoic acid)-1,10-phenanthroline. The two complexes though exhibit very strong molar extinction coefficient values; however, [Ru(L1)2(NCS)2] shows better characteristic broad and intense metal-to-ligand charge transfer (MLCT) absorption band and higher molar absorptivity coefficient at (λmax=522 nm, ε=6.60×104 M−1 cm−1) than that of [Ru(L2)2(NCS)2] complex, (λmax=446 nm, ε=4.82×104 M−1 cm−1). At room temperature, long wavelength emissions with strong intensity ratio centered at 660 nm were recorded for [Ru(L1)2(NCS)2] complex with a bathochromic shift (λem=700 nm) for [Ru(L2)2(NCS)2] complex. It was shown that the luminescence wavelength characteristic of the complexes may be a function relating to the increasing length of π-conjugation and/or molecular weight. A preliminary cyclic voltammetry of [Ru(L1)2(NCS)2] complex also exhibits good electroredox activity with oxidation potential of about 1.04 V, significantly better than other Ru(II) polypyridine complexes containing bidentate ligands.

The synthesis of single- and double-decked anthracenyl functionalized ruthenium(II) phthalocyanine complexes has been achieved through a controlled electrophilic aromatic substitution reaction of the free unsubstituted ruthenium(II) phthalocyanine with preformed 9-bromo-10-(2,3-dimethylacrylic acid)-anthracene and/or 9-bromo-10-(2,3-dimethylacrylic acid)-dianthracene using 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) as catalyst. The complexes were characterized by IR, UV-Vis, fluorescence, 1H, 13C NMR, and elemental analyses. A dimeric complex (C3R′′RuPc, where R′′ is 9-dianthracenyl-10-(2,3-dimethylacrylic acid), obtained as the major product of the dianthracenyl-substituted ruthenium phthalocyanine complex displays a strong near-infrared visible absorption band wavelength maxima at 1027 nm (ε=5.47×103 M−1 cm−1), with an interesting photoluminescent and electroredox active properties.

Different density functional methods (DFT) have been used to optimize and study the chemistry of five potential anticancer complexes in terms of their electronic, conductive, and spectroscopic properties. Many of the computed properties in addition to the IR and QTAIM analysis of the NMR are dipole moment vector (μi), linear polarizability tensor (αij), first hyperpolarizability tensors (βijk), polarizability exaltation index (Γ), and chemical hardness (η) of the complexes. Stable low energy geometries are obtained using basis set with effective core potential (ECP) approximation but, in the computation of atomic or molecular properties, the metal Ru atom is better treated with higher all electron basis set like DGDZVP. The spectroscopic features like the IR of the metal-ligand bonds and the isotropic NMR shielding tensor of the coordinated atoms are significantly influenced by the chemical environment of the participating atoms. The carboxylic and pyrazole units are found to significantly enhance the polarizabilities and hyperpolarizabilities of the complexes while the chloride only improves the polarity of the complexes. Fermi contacts (FC) have the highest effect followed by the PSO among all the four Ramsey terms which defined the total spin-spin coupling constant J (HZ) of these complexes.

With the aim of developing new molecular devices having long-range electron transfer in artificial systems and as photosensitizers, a series of homoleptic ruthenium(II) bisterpyridine complexes bearing one to three anthracenyl units sandwiched between terpyridine and 2-methyl-2-butenoic acid group are synthesized and characterized. The complexes formulated as bis-4′-(9-monoanthracenyl-10-(2-methyl-2-butenoic acid) terpyridyl) ruthenium(II) bis(hexafluorophosphate) (RBT1), bis-4′-(9-dianthracenyl-10-(2-methyl-2-butenoic acid) terpyridyl) ruthenium(II) bis(hexafluorophosphate) (RBT2), and bis-4′-(9-trianthracenyl-10-(2-methyl-2-butenoic acid) terpyridyl) ruthenium(II) bis(hexafluorophosphate) (RBT3) were characterized by elemental analysis, FT-IR, UV-Vis, photoluminescence, 1H and 13C NMR spectroscopy, and electrochemical techniques by elemental analysis, FT-IR, UV-Vis, photoluminescence, 1H and 13C NMR spectroscopy, and electrochemical techniques. The cyclic voltammograms (CVs) of (RBT1), (RBT2), and (RBT3) display reversible one-electron oxidation processes at E1/2 = 1.13 V, 0.71 V, and 0.99 V, respectively (versus Ag/AgCl). Based on a general linear correlation between increase in the length of π-conjugation bond and the molar extinction coefficients, the Ru(II) bisterpyridyl complexes show characteristic broad and intense metal-to-ligand charge transfer (MLCT) band absorption transitions between 480–600 nm, ε=9.45×103 M−1 cm−1, and appreciable photoluminescence spanning the visible region.

Metal sulfides nanoparticles in poly(methyl methacrylate) matrices were prepared and characterized by infrared spectroscopy, thermogravimetric analysis, powder X-ray diffraction, scanning electron microscope (SEM), and transmission electron microscope (TEM). The FTIR confirms the dispersion of the nanoparticles in PMMA matrices with the C=O and C–O–C bonds of the PMMA shifting slightly which may be attributed to the interactions between the nanoparticles and PMMA. The ZnS nanoparticles in PMMA have average crystallite sizes of 4–7 nm while the CdS has particle size of 10 nm and HgS has crystallite sizes of 8–20 nm. The increasing order of particle sizes as calculated from the XRD is ZnS/PMMA

Pd(II) and Pt(II) complexes of trimethoprim and pyrimethamine were synthesized and characterized by elemental analysis, UV-Vis, FTIR, and NMR spectroscopy. The complexes are formulated as four coordinate square planar species containing two molecules of the drugs and two chloride or thiocyanate ions. The coordination of the metal ions to the pyrimidine nitrogen atom of the drugs was confirmed by spectroscopic analyses. The complexes were screened for their antibacterial activities against eight bacterial isolates. They showed varied activities with the active metal complexes showing more enhanced inhibition than either trimethoprim or pyrimethamine. The Pd(II) complexes of pyrimethamine showed unique inhibitory activities against P. aeruginosa and B. pumilus, and none of the other complexes or the drugs showed any activity against these bacteria isolates. The MIC and MBC determinations revealed that these Pd(II) complexes are the most active. Structure activity relationship showed that Pt(II) complexes containing chloride ions are more active, while for Pd(II) complexes containing thiocyanate ions showed more enhanced activity than those containing chloride ions.

Substituted thiourea ligands are of interest because they possess various donor sites for metal ions and their application in separation of metal ions and as antimicrobial agents. The coordination of the sulfur donor atom led to interest in them as precursor for semiconductor nanoparticles. In this study, cadmium(II) complex of diethylthiourea was synthesized and characterized by elemental analysis, FTIR, and X-ray crystallography. Single crystal X-ray structure of the complex showed that the octahedral geometry around the Cd ion consists of two molecules of diethylthiourea acting as monodentate ligands and two chelating acetate ions. The thermal decomposition of the compound showed that it decomposed to give CdS. The compound was thermolysed in hexadecylamine (HDA) to prepare HDA-capped CdS nanoparticles. The absorption spectrum showed blue shifts in its absorption band edges which clearly indicated quantum confinement effect, and the emission spectrum showed characteristic band edge luminescence. The broad diffraction peaks of the XRD pattern showed the materials to be of the nanometric size.

The factors that determine the stability and the effects of noncovalent interaction on the η6-arene ruthenium anticancer complexes are determined using DFT method. The intramolecular and intra-atomic properties were computed for two models of these half-sandwich ruthenium anticancer complexes and their respective hydrated forms. The results showed that the stability of these complexes depends largely on the network of hydrogen bonds (HB), strong nature of charge transfer, polarizability, and electrostatic energies that exist within the complexes. The hydrogen bonds strength was found to be related to the reported anticancer activities and the activation of the complexes by hydration. The metal–ligand bonds were found to be closed shell systems that are characterised by high positive Laplacian values of electron density. Two of the complexes are found to be predominantly characterised by LMCT while the other two are predominately characterised by MLCT.

The title compound, C32H29NP2S2, has two molecules in the asymmetric unit, with an r.m.s. difference of 0.218 Å in their best-fit overlay. Both molecules have a slightly distorted trigonal–planar N atom, bonded to two PV atoms and a C atom of the 4-ethylphenyl unit. The P—N—P angles of 126.34 (11) and 125.98 (11)° are larger than the four C—N—P bond angles. The two S atoms are trans to one another with respect to the P—N—P angle. The crystal structure features C—H...π interactions. The methyl group in one of the molecules is disordered over two sets of sites, with occupancies of 0.518 (6) and 0.482 (6).