New trends for metal complexes with anticancer activity

Medicinal inorganic chemistry can exploit the unique properties of metal ions for the design of new drugs. This has, for instance, led to the clinical application of chemotherapeutic agents for cancer treatment, such as cisplatin. The use of cisplatin is, however, severely limited by its toxic side-effects. This has spurred chemists to employ different strategies in the development of new metal-based anticancer agents with different mechanisms of action. Recent trends in the field are discussed in this review. These include the more selective delivery and/or activation of cisplatin-related prodrugs and the discovery of new non-covalent interactions with the classical target, DNA. The use of the metal as scaffold rather than reactive centre and the departure from the cisplatin paradigm of activity towards a more targeted, cancer cell-specific approach, a major trend, are discussed as well. All this, together with the observation that some of the new drugs are organometallic complexes, illustrates that exciting times lie ahead for those interested in ‘metals in medicine

Gallium-promoted HZSM-5 zeolites as efficient catalysts for the aromatization of biomass-derived furans

\u3cp\u3eThe development of novel technologies to convert renewable biomass feedstocks to fuels and chemicals is of increasing interest for making our chemical industry more sustainable. Plant biomass or its biomass-derived platform molecules are typically over-functionalized, requiring substantial modification to produce the chemicals currently demanded by industry. Furanic compounds are intermediates in the catalytic fast pyrolysis of lignocellulosic biomass or sugar dehydration and can in principle be further converted to aromatics. While upgrading of furanics by zeolite-catalysed aromatization typically results in a large loss of carbon due to coke deposition, carbon laydown can be mitigated by the addition of ethylene and by the modification of the zeolite with Lewis acid Ga sites. Here, we investigate the influence of the Ga loading on the physicochemical properties of Ga-modified HZSM-5 zeolite and its performance in the gas-phase aromatization of 2,5-dimethylfuran with ethylene. Characterization of the morphological, textural and acidic properties were carried out to understand the role of Brønsted and Lewis acid sites on the catalytic reaction. We demonstrate a crucial role of the dispersion of Ga-species and the resulting Lewis acidity of the Ga/ZSM-5 catalysts; and show means how to control both parameters by adjusting the synthesis method.\u3c/p\u3

Single-Molecule Fluorescence Microscopy Reveals Local Diffusion Coefficients in the Pore Network of an Individual Catalyst Particle

We used single-molecule fluorescence microscopy to study self-diffusion of a feedstock-like probe molecule with nanometer accuracy in the macropores of a micrometer-sized, real-life fluid catalytic cracking (FCC) particle. Movies of single fluorescent molecules allowed their movement through the pore network to be reconstructed. The observed tracks were classified into three different states by machine learning and all found to be distributed homogeneously over the particle. Most probe molecules (88%) were immobile, with the molecule most likely being physisorbed or trapped; the remainder was either mobile (8%), with the molecule moving inside the macropores, or showed hybrid behavior (4%). Mobile tracks had an average diffusion coefficient of D = 8 × 10-14 ± 1 × 10-13 m2 s-1, with the standard deviation thought to be related to the large range of pore sizes found in FCC particles. The developed methodology can be used to evaluate, quantify and map heterogeneities in diffusional properties within complex hierarchically porous materials.status: publishe