193 research outputs found
The Importance of Chemistry for Nanotechnology
The paradigm shift from uniform bulk materials towards nanostructured multifunctional materials is essential for future knowledge transfer from fundamental to applied sciences. In nanotechnology, two approaches are employed: “top-down” and “bottom-up”. In the top-down approach, larger assemblies are broken down to smaller units, while the bottom-up approach makes use of atomic or molecular building blocks to construct the desired nanostructures. Chemistry plays a major role in the bottom-up approach by providing progressive building blocks, such as “smart” molecules, that can be combined — preferentially by self-organisation — to create fundamentally new classes of materials. The ultimate goal is to create environmentally friendly, highly efficient, low-cost devices serving multifunctional purposes for a steadily more diversified modern societ
Platinum Metal Complexes of Carbaboranylphophines: Potential Anti Cancer Agents
Polyhedral heteroboranes in particular dicarba-closo-dodecaboranes(12) and their organic derivatives have been the subject of intense research for over 40 years due to their unique chemical and physical properties. The initial attraction to dicarba-closo-dodecaboranes(12) In the medicinal chemistry research, was a result of their high boron content and stability to catabolism, which are important criteria for cancer therapy, such as BNCT (boron neutron capture therapy) agents. The coordination compounds of the platinum group metals have also received large interest for their potential application as chemotherapeutic agents, since cis-diamminedichloroplatinum(II), cisplatin, has been reported to have capability as tumor inhibitor. Hence, applications can be envisioned for related cis platinum complexes. Complex of cis-rac-[PtCl2{1,2-(PRCl)2C2B10H10}] (R=Ph, tBu, NEt2, NPh2) have been synthesized by employing known carbaborane based phosphine ligands of clorophoshino-closo-dodecaborane , with complex of cis-[PtCl2(COD)] (COD = 1,5-cyclooctadiene) in an N2-atmosphere. The obtained complexes possess expected structure configuration, namely cis-rac. The characterization of the complex has been carried out using 1H, 31P, 13C and 11B-NMR (Nuclear Magnetic Resonance), X-ray of single crystals, elemental analysis, IR (infra red) and mass spectroscopy (MS). The 31P{1H} NMR spectra of all the platinum complexes distinctly show the typical platinum satellites which are attributed to 31P-195Pt-coupling, in which the 31P{1H} NMR spectrum exhibits three lines with an intensity ratio of ca.1:4:1. The structure of the platinum complexes consists of a slightly distorted square-planar coordination sphere, in which the platinum atom is bonded to two chlorides and two phosphorus atoms of the chelating carbaboranylphosphine. Thus the platinum atoms exhibit the coordination number four, which is preferred in platinum(II) complexes.Keywords: Platinum complexes, phosphine ligand, carbaboran
Enlargement of a Modular System—Synthesis and Characterization of an s-Triazine-Based Carboxylic Acid Ester Bearing a Galactopyranosyl Moiety and an Enormous Boron Load
The amount of boron accumulated in tumor tissue plays an important role regarding the
success of the boron neutron capture therapy (BNCT). In this article, we report a modular system,
combining readily available starting materials, like glycine, 1,3,5-triazine and the well-known
9-mercapto-1,7-dicarba-closo-dodecaborane(12), as well as alpha-d-galactopyranose for increased
hydrophilicity, with a novel boron-rich tris-meta-carboranyl thiol
3D Printed Palladium Catalyst for Suzuki-Miyaura Cross-coupling Reactions
Selective laser sintering (SLS) 3d printing was utilized to manufacture a solid catalyst for Suzuki-Miyaura cross-coupling reactions from polypropylene as a base material and palladium nanoparticles on silica (SilicaCat Pd(0)R815-100 by SiliCycle) as the catalytically active additive. The 3d printed catalyst showed similar activity to that of the pristine powdery commercial catalyst, but with improved practical recoverability and reduced leaching of palladium into solution. Recycling of the printed catalyst led to increase of the induction period of the reactions, attributed to the pseudo-homogeneous catalysis. The reaction is initiated by oxidative addition of aryl iodide to palladium nanoparticles, resulting in formation of soluble molecular species, which then act as the homogeneous catalyst. SLS 3d printing improves handling, overall practicality and recyclability of the catalyst without altering the chemical behaviour of the active component.Peer reviewe
Ruthenacarborane–Phenanthroline Derivatives as Potential Metallodrugs
Ruthenium-based complexes have received much interest as potential metallodrugs. In this work, four RuII complexes bearing a dicarbollide moiety, a carbonyl ligand, and a phenanthroline-based ligand were synthesized and characterized, including single crystal diffraction analysis of compounds 2, 4, and 5 and an observed side product SP1. Complexes 2–5 are air and moisture stable under ambient conditions. They show excellent solubility in organic solvents, but low solubility in water
Convenient synthesis of carbamates, S-alkyl thiocarbamates, and N,N′-disubstituted urea derivatives of methoxycarbonylsulfenyl isocyanate
Convenient simple and suitable methods for the synthesis of carbamates, N,N′-unsymmetrically disubstituted ureas, and S-alkyl thiocarbamates derived from CH3OC(O)SNCO in one-step are provided. Reactions are operationally simple and have high selectivity toward nitrogen, oxygen, and sulfur nucleophiles. The absence of solvents coupled with high yields and short reaction times make these procedures very attractive for synthesis.Fil: Torrico Vallejos, Sonia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Química Inorgánica "Dr. Pedro J. Aymonino". Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Centro de Química Inorgánica "Dr. Pedro J. Aymonino"; ArgentinaFil: Erben, Mauricio Federico. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Química Inorgánica "Dr. Pedro J. Aymonino". Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Centro de Química Inorgánica "Dr. Pedro J. Aymonino"; ArgentinaFil: Hey Hawkins, Evamarie. Universitat Leipzig; AlemaniaFil: Della Vedova, Carlos Omar. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Química Inorgánica "Dr. Pedro J. Aymonino". Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Centro de Química Inorgánica "Dr. Pedro J. Aymonino"; Argentin
Bipyraloxifene – a modified raloxifene vector against triple-negative breast cancer
Raloxifene, a selective oestrogen receptor modulator (SERM), has demonstrated efficacy in the prevention and therapy of oestrogen receptor-positive (ER+) breast cancer, with some degree of effectiveness against triple-negative forms. This suggests the presence of oestrogen receptor-independent pathways in raloxifene-mediated anticancer activity. To enhance the potential of raloxifene against the most aggressive breast cancer cells, hybrid molecules combining the drug with a metal chelator moiety have been developed. In this study, we synthetically modified the structure of raloxifene by incorporating a 2,2′-bipyridine (2,2′-bipy) moiety, resulting in [6-methoxy-2-(4-hydroxyphenyl)benzo[b]thiophen-3-yl]-[4-(2,2′-bipyridin-4′-yl-methoxy)phenyl]methanone (bipyraloxifene). We investigated the cytotoxic activity of both raloxifene and bipyraloxifene against ER+ breast adenocarcinomas, glioblastomas, and a triple-negative breast cancer (TNBC) cell line, elucidating their mode of action against TNBC. Bipyraloxifene maintained a mechanism based on caspase-mediated apoptosis but exhibited significantly higher activity and selectivity compared to the original drug, particularly evident in triple-negative stem-like MDA-MB-231 cells
[Disulfanediylbis(ferrocenylthiophosphinato)-κ2 O,O]titanocene tetrahydrofuran trisolvate
The title compound, [Fe2Ti(C5H5)4)(C10H8O2P2S4)]·3C4H8O, contains a central seven-membered TiO2P2S2 ring with a very similar geometry compared to the derivative showing anisyl instead of ferrocenyl substituents, the Ti—O distance being marginally longer for the anisyl derivative. Two tetrahydrofuran solvent molecules are each disordered on a twofold axis
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