Studies on anticancer properties with varying co-ligands in a Ru(II) arene benzimidazole system.

Recently in the field of chemotherapeutics, to combat the side effects of cisplatin, ruthenium complexes have been investigated extensively. In this work, a bidentate benzimidazole-based ligand, HL [HL = 2-(1-benzo[]imidazol-2-yl)-6-methoxyphenol], was utilized to obtain three Ru(II) arene complexes having a generalized formula [Ru(η--cym)(L)(X)] or [Ru(η--cym)(L)(X)] (where -cym = -cymene). The co-ligand X (X = (i) Cl, (ii) PPh = triphenyl phosphine, and (iii) PTA = 1,3,5-triaza-7-phosphaadamantane) was varied in order to study the effect it has on the antitumor activity of the compounds.

Pre-arranged building block approach for the orthogonal synthesis of an unfolded tetrameric organic-inorganic phosphazane macrocycle.

Inorganic macrocycles remain challenging synthetic targets due to the limited number of strategies reported for their syntheses. Among these species, large fully inorganic cyclodiphosphazane macrocycles have been experimentally and theoretically highlighted as promising candidates for supramolecular chemistry. In contrast, their hybrid organic-inorganic counterparts are lagging behind due to the lack of synthetic routes capable of controlling the size and topological arrangement (i.

Dinuclear and mononuclear metal(II) polypyridyl complexes against drug-sensitive and drug-resistant Plasmodium falciparum and their mode of action.

Background: Malaria remains one of the most virulent and deadliest parasitic disease in the world, particularly in Africa and Southeast Asia. Widespread occurrence of artemisinin-resistant Plasmodium falciparum strains from the Greater Mekong Subregion is alarming. This hinders the national economies, as well as being a major drawback in the effective control and elimination of malaria worldwide.

A binuclear Cu(II) complex as an efficient photocatalyst for -alkylation of aromatic amines.

Visible-light driven photoreactions using transition metal complexes as catalysts are currently a research hotspot in developing environmentally friendly sustainable processes. To develop a potential copper-based photocatalyst, a binuclear Cu(II) complex has been synthesized using a Mannich base ligand . 2,4-dichloro-6-((4-(2-hydroxyethyl)piperazin-1-yl)methyl)phenol ().

Pyrene-based fluorescent Ru(II)-arene complexes for significant biological applications: catalytic potential, DNA/protein binding, two photon cell imaging and cytotoxicity.

Ruthenium complexes are being studied extensively as anticancer drugs following the inclusion of NAMI-A and KP1019 in phase II clinical trials for the treatment of metastatic phase and primary tumors. Herein, we designed and synthesized four organometallic Ru(II)-arene complexes [Ru(η--cymene)(L)Cl] (1), [Ru(η-benzene)(L)Cl] (2), [Ru(η--cymene)(L)N] (3) and [Ru(η-benzene)(L)N] (4) [HL = ()-'-(pyren-1-ylmethylene)thiopene-2-carbohydrazide] that have anticancer, antimetastatic and two-photon cell imaging abilities. Moreover, in the transfer hydrogenation of NADH to NAD, these compounds also display good catalytic activity.

Group VIII Metal Carbonyl Cluster-Boronic Acid Conjugates: Cytotoxicity and Mode of Action Studies.

A set of metal carbonyl cluster-boronic acid conjugates of the group VIII metals (Fe, Ru, and Os) were synthesized and their antiproliferative effects measured against two breast cancer cell lines (MCF-7 and MDA-MB-231) and a noncancerous breast epithelial (MCF-10A) cell line. The cytotoxicity followed the order Ru > Os > Fe for the MDA-MB-231 cells, although the latter two exhibited similar cytotoxicity against MCF-7 and MCF-10A cells. The osmium species {Os(CO)(μ-H)[μ-SCH--B(OH)]} () could be chemically oxidized to its hydroxy analogue [Os(CO)(μ-H)(μ-SCH -OH)] (), which showed comparable cytotoxicity.

Mechanosynthesis of Higher-Order Cocrystals: Tuning Order, Functionality and Size in Cocrystal Design*.

The ability to rationally design and predictably construct crystalline solids has been the hallmark of crystal engineering research. To date, numerous examples of multicomponent crystals comprising organic molecules have been reported. However, the crystal engineering of cocrystals comprising both organic and inorganic chemical units is still poorly understood and mostly unexplored.

Size-control in the synthesis of oxo-bridged phosphazane macrocycles via a modular addition approach.

Inorganic macrocycles remain largely underdeveloped compared with their organic counterparts due to the challenges involved in their synthesis. Among them, cyclodiphosphazane macrocycles have shown to be promising candidates for supramolecular chemistry applications due to their ability to encapsulate small molecules or ions within their cavities. However, further developments have been handicapped by the lack of synthetic routes to high-order cyclodiphosphazane macrocycles.

Tuning the π-π overlap and charge transport in single crystals of an organic semiconductor via solvation and polymorphism.

Polymorphism is a central phenomenon in materials science that often results in important differences of the electronic properties of organic crystals due to slight variations in intermolecular distances and positions. Although a large number of π-conjugated organic compounds can grow as polymorphs, it is necessary to have at disposal a series of several polymorphs of the same molecule to establish clear and predictive structure-property relationships. We report here on the occurrence of two solvates and three polymorphs in single crystalline form of the organic p-type semiconductor 2,2',6,6'-tetraphenyldipyranylidene (DIPO).

N-Bridged Acyclic Trimeric Poly-Cyclodiphosphazanes: Highly Tuneable Cyclodiphosphazane Building Blocks.

We have synthesized a completely new family of acyclic trimeric cyclodiphosphazane compounds comprising NH, N Pr, N Bu and NPh bridging groups. In addition, the first NH-bridged acyclic dimeric cyclophosphazane has been produced. The trimeric species display highly tuneable characteristics so that the distance between the terminal N(H)R moieties can be readily modulated by the steric bulk present in the bridging groups (ranging from ≈6 to ≈10 Å).

Synthesis, characterization, theoretical, molecular docking and biological activity studies of Ru(II) (--cymene) complexes with novel aniline substituted aroyl selenoureas.

A sequence of aroyl selenourea ligands ( substituted by aniline and their Ru(II) (--cymene) complexes , [Ru(II) (--cymene) L] (L = monodentate aroyl selenourea ligand) have been synthesized and characterized the composition of the ligands and their metal complexes. The molecular structures of ligand and complex were also confirmed by single XRD crystal method. The single-crystal XRD study showed that aroyl selenourea ligand coordinates with Ru Se novel neutral monodentate atom.

Carbodicarbene Ligand Redox Noninnocence in Highly Oxidized Chromium and Cobalt Complexes.

Carbodicarbenes (CDCs) possess two lone pairs of electrons on their central carbone C atom (C). Coordination to a transition metal via a σ bond leaves one pair of electrons with appropriate symmetry for π donation to the metal. However, the high energy of the latter also renders the CDC ligand potentially redox-active.

Effect of Carbazolyl Groups on Photophysical Properties of Cyanuric Chloride.

Long-lived room temperature organic phosphorescence is highly useful in biological imaging, electroluminescent devices, information security, and security protection on account of its unique photophysical process and long-lived luminescence. In recent years, pure organic phosphorescent materials that do not contain rare precious metals have received increasing attention. Carbazole and its derivatives have been used to develop room temperature organic phosphorescent materials.

Novel Approach to Generate a Self-Deliverable Ru(II)-Based Anticancer Agent in the Self-Reacting Confined Gel Space.

Finding the most effective method for cancer treatment is one of the thought-provoking tasks. Drug delivery by collapsing of metallogel to the cancer cell is an appealing way out. Cancer cells have an acidic environment due to excessive accumulation of lactic acid.

Cobalt Metallogel Interface for Selectively Sensing l-Tryptophan among Essential Amino Acids.

The development of metallogels widens the span of sensing activity as it opens new opportunities to develop chemosensors through metal-ligand interactions. Herein, a new nitrile-substituted 1,3,5-tricarboxamide-based gelator G4 has been fabricated and shows aggregate-induced enhanced emission (AIEE) after gelation in the presence of water. A dimethylformamide (DMF) solution of the gelator shows rapid crystallization, but addition of water to a DMF solution of gelator G4 leads to gelation at room temperature.

Enantiomeric pairs of ternary copper(ii) complexes and their aldol-type condensation products: synthesis, characterization, and anticancer and epigenetic properties.

Chiral enantiomers [Cu(phen)(l-ser)(H2O)]NO31 and [Cu(phen)(d-ser)(H2O)]NO32 (ser = serinato) underwent aldol-type condensation with formaldehyde, with retention of chirality, to yield their respective enantiomeric ternary copper(ii) complexes, viz. l- and d-[Cu(phen)(OCA)(H2O)]NO3·xH2O (3 and 4; phen = 1,10-phenanthroline; OCA = oxazolidine-4-carboxylate; x = 1/2, 0-2) respectively. These chiral complexes were characterized by FTIR, elemental analysis, circular dichroism, UV-visible spectroscopy, fluorescence spectroscopy (FL), molar conductivity measurement, ESI-MS and X-ray crystallography.

Hydrophobic Metal Halide Perovskites for Visible-Light Photoredox C-C Bond Cleavage and Dehydrogenation Catalysis.

Two-dimensional lead and tin halide perovskites were prepared by intercalating the long alkyl group 1-hexadecylammonium (HDA) between the inorganic layers. We observed visible-light absorption, narrow-band photoluminescence, and nanosecond photoexcited lifetimes in these perovskites. Owing to their hydrophobicity and stability even in humid air, we applied these perovskites in the decarboxylation and dehydrogenation of indoline-2-carboxylic acids.

Stibine-protected Au nanoclusters: syntheses, properties and facile conversion to GSH-protected Au nanocluster.

Monostibine-protected ionic Au nanoclusters, namely, [Au(L)(Cl)][Cl] (L= SbPh, ·Cl; Sb(-tolyl), ·Cl) were prepared by the direct reduction of Au(L)Cl with NaBH in dichloromethane. Anion exchange with ·Cl afforded [Au(SbPh)(Cl)][X] (X = PF, ·PF; BPh, ·BPh). All these have been characterized by multinuclear NMR, ESI-MS and UV-Vis spectroscopy.

Visible Light Driven Hydrogen Evolution by Molecular Nickel Catalysts with Time-Resolved Spectroscopic and DFT Insights.

Hydrogen (H) is a clean fuel that can potentially be a future solution for the storage of intermittent renewable energy. However, current H production is mainly dominated by the energy intensive steam reforming reaction, which consumes a fossil fuel, methane, and emits copious amounts of carbon dioxide as one of the byproducts. To address this challenge, we report a molecular catalyst that produces H from aqueous solutions, is composed of affordable, earth-abundant elements such as nickel, and has been incorporated into a system driven by visible light.

Synthesis and Electronic Properties of Novel 5,7-Diazapentacene Derivatives.

A route to the synthesis of novel 5,7-diazapentacenes and some preliminary studies on their properties is reported. A single crystal X-ray diffraction study of the dihexyl derivative showed it had formed a dimer during the analysis. The materials possess lower lying frontier orbitals than pentacene and may have potential applications in organic electronic devices.

Two-Dimensional and Emission-Tunable: An Unusual Perovskite Constructed from Lindqvist-Type [PbBr] Nanoclusters.

Preparing low-dimensional perovskite materials with novel building units is highly desirable because such materials have already been demonstrated to show unusual physical properties. In this report, we first reported a new and unusual two-dimensional perovskite framework, [B(HIm)]PbBr (1), constructed from novel Lindqvist-type [PbBr] nanoclusters. The as-prepared material shows good water resistance and chemical/heat stability.

Observation of Carbodicarbene Ligand Redox Noninnocence in Highly Oxidized Iron Complexes.

To probe the possibility that carbodicarbenes (CDCs) are redox active ligands, all four members of the redox series [Fe(1) ] (n=2-5) were synthesized, where 1 is a neutral tridentate CDC. Through a combination of spectroscopy and DFT calculations, the electronic structure of the pentacation is shown to be [Fe (1 ) ] (S= ). That of [Fe(1) ] is more ambiguous, but it has significant contributions from the open-shell singlet [Fe (1)(1 )] (S=0).

Embedding a Ruthenium-Based Structural Mimic of the [Fe]-Hydrogenase Cofactor into Papain.

We describe the synthesis of the ruthenacyclic carbamoyl complexes [Ru(2-NHC(O)CHNMe)(CO)( o,o-Me-CHS)(L)] (L = HO or MeCN), which have a labile water or acetonitrile ligand at their sixth coordination sites. Steric bulk around the ruthenium center is essential in preventing isomerization and dimerization, and embedding within papain can be achieved via coordination of its sole free cysteine residue. The observed chemistry parallels that of the natural [Fe]-hydrogenase.

Pyrene-Containing Twistarene: Twelve Benzene Rings Fused in a Row.

Success in obtaining higher-order twistarenes with precise structures is very important for fundamentally understanding the relationship between the structures and physical properties/optoelectronic applications. In this research, by using the advantages from a retro-Diels-Alder process (clean reaction) and the cross-conjugated nature of the pyrene unit, a novel dodeca-twistarene was prepared for the first time. Its structure, confirmed by single-crystal XRD analysis, indicates that it possesses a twisted angle (≈30°), and two neighboring molecules in the crystal lattice are perpendicular to each other because of the twisted character and the strong intermolecular CH-π interactions.

Synthesis of Unique Phosphazane Macrocycles via Steric Activation of C-N Bonds.

Herein we describe that oxidation reactions of the dimeric cyclophosphazanes, [{P(μ-NR)}(μ-NR)], R = Bu (1), to produce a series of diagonally dioxidized products P(μ-N Bu)E [E = O (2), S (3), and Se (4)] and tetraoxidized frameworks. The latter display an unexpected C-N bond activation and cleavage to produce a series of novel phosphazane macrocyclic arrangements containing newly formed N-H bonds. Macromolecules P(μ-N Bu)(μ-NH)O (5) and P(μ-N Bu)(μ-NH)E, E = S (6) and Se (7), dicleaved and tricleaved products, respectively, are rare examples of dimeric macrocycles containing NH bridging groups.