Dalton Transactions

doi: 10.1039/d5dt90092apmid: N/A

doi: 10.1039/d5dt90093jpmid: N/A

doi: 10.1039/d5dt90094hpmid: N/A

Ansari, Eklakh; Kumar, Ravi; Ratnam, Anand

doi: 10.1039/d5dt00118hpmid: 40171803

Recent advancements in Au(i)–N-heterocyclic carbene (NHC) complexes have demonstrated significant potential for developing novel anticancer agents. These complexes exhibit unique properties, such as a strong affinity for thiol and selenol-containing biomolecules, which enable the selective targeting of cancer cells while minimising effects on healthy tissues. Recent studies have explored various structural modifications to enhance the anticancer efficacy of Au(i)–NHC complexes, including ligand substitution, incorporation of bioactive moieties, and hybridisation with other metal complexes. Mechanistic investigations have revealed that these complexes induce apoptosis through multiple pathways, such as inhibition of thioredoxin reductase (TrxR), disruption of mitochondrial function, and generation of reactive oxygen species (ROS). The introduction of NHC ligands is particularly advantageous, as they provide stability and tunability to the Au(i) centre, allowing for the optimisation of pharmacokinetic and pharmacodynamic properties. Moreover, the emergence of Au(i)–NHC complexes with dual-action mechanisms, combining anticancer activity with antiangiogenic or anti-inflammatory properties, has further broadened their therapeutic potential. This review article highlights the most recent breakthroughs in the design, synthesis, and biological evaluation of Au(i)–NHC complexes, emphasizing their promise as a new class of targeted anticancer therapeutics. While primarily focused on Au(i) complexes, it also includes a brief discussion of selected Au(iii) complexes for comparison.

U, Sreelekha; Chakrabarty, Rinku; Paira, Priyankar

doi: 10.1039/d5dt00610dpmid: 40326188

Metal complexes exhibit significant potential in the field of anticancer metallotherapeutics due to their high selectivity toward cancer cells and their effectiveness in targeted drug delivery. This frontier article summarizes recent advances in the synthesis of mono-, bi-, and mixed-metallic Ru(ii)/Ir(iii)/Re(i)/Rh(iii) complexes for anticancer applications. Additionally, various therapeutic approaches and their mechanisms of action in Ru(ii)/Ir(iii)/Re(i)/Rh(iii)-based complexes are discussed. In this study, we provide insights into the contributions of various research groups toward the development of transition metal complexes with promising therapeutic potential. This study also addresses the challenges encountered throughout the designing and application process as well as the future perspectives of these metallopharmaceuticals.

Seisenbaeva, Gulaim A.; Kloo, Lars; Agback, Peter; Kessler, Vadim G.

doi: 10.1039/d5dt00348bpmid: 40293156

Polymerization isomerism is potentially important for metal alkoxides as precursors of oxide materials. Here, we present this phenomenon for tungsten oxo-methoxide, reporting the molecular and crystal structure of its polymeric form [WO(OMe)4]∞(1), its dimeric form W2O2(OMe)8(2), and a higher extent oxo-substituted by-product of the synthesis, Li2(MeOH)6W12O29(OMe)16(3).

Parmar, Vijay S.; Gransbury, Gemma K.; Corner, Sophie C.; Chou, Wei-Hao; Hill, Stephen; Winpenny, Richard E. P.; Chilton, Nicholas F.; Mills, David P.

doi: 10.1039/d5dt00862jpmid: 40272390

Two heteroleptic octahedral Dy(iii) cis-aryloxide complexes, [Dy(OPh*)2(THF)3X] {HOPh* = 2,6-bis(diphenyl-methyl)-4-tert-butylphenol; X = Cl (1), Br (2)}, have been characterised by multi-frequency electron paramagnetic resonance (EPR) spectroscopy to determine gz = 18.9(1) for 1 and 18.3(6) for 2. These are rare examples of Dy(iii) single-molecule magnets that have observable EPR spectra.

Ferdov, Stanislav; Gonçalves, Renato

doi: 10.1039/d5dt00723bpmid: 40289650

Microwave heating of FAU zeolite in alkaline solutions results in transformations into EDI, MER, LTJ, CAN, and ANA-type zeolites. The use of microwaves significantly accelerates the synthesis and uncovers a previously unobserved transformation to LTJ-type zeolite.

Brown, Ryan K.; Bunyan, Joseph N.; Agrawal, Ashi; Li, Guoyu; Dautoras, Dominykas; Sarker, Jagodish C.; Keat, Terng Tor; Hicks, Thomas; Hogarth, Graeme; Pugh, David

doi: 10.1039/d5dt00240kpmid: 40123519

The cytotoxic series of cis-platin mimics “[AuX2(dtc)]” (X = Cl, Br; dtc = dithiocarbamate) were recently patented as promising anticancer metallotherapeutics. Using a range of dialkyl-, cyclic alkyl- and diaryl-dithiocarbamate ligands, we have discovered that “[AuX2(dtc)]” actually exist in solution as a mixture containing neutral [AuX2(dtc)] and cationic [Au(dtc)2]+. For the latter, single crystal X-ray crystallography proved that a variety of halide-containing anions such as [AuX4]−, [AuX2]− and even X− balanced the charge. Based on a thorough investigation into the synthesis of these compounds, we discovered that literature syntheses which claim to produce pure material in fact generate mixtures. In some cases the major component of the mixture is actually the cationic [Au(dtc)2]+ rather than the claimed neutral [AuX2(dtc)]. Refinement of the synthetic conditions led to a mixture where the neutral [AuX2(dtc)] was the dominant component, from which pure solid [AuX2(dtc)] could be obtained by fractional crystallisation. However, the isomerisation process immediately restarted upon dissolution of the crystalline material, thus it is not possible to obtain pure [AuX2(dtc)] in solution. This discovery has important ramifications for any future use of these compounds, especially as therapeutics since the solution-phase speciation means that “pure” [AuX2(dtc)] cannot exist under biologically relevant conditions. A critical reinterpretation of existing literature data demonstrates that there is already significant uncertainty surrounding which component(s) of this mixture are biologically active.

Yasmeen, Rashida; Islam, Sheikh M. S.; Ayeni, Olajumoke M.; Moghadam, Peyman Z.; Du, Jincheng; Omary, Mohammad A.

doi: 10.1039/d5dt00242gpmid: 40264249

Herein, we report carbon dioxide (CO2) and methane (CH4) adsorption behavior in MeMOFs, methylated analogues of FMOFs with −CF3 groups replaced with −CH3, utilizing grand canonical Monte Carlo (GCMC) simulations at 288, 298, and 308 K and P ≤ 40 bar and density functional theory (DFT) computations of adsorption energies. Isosteric heats of adsorption (Qst), Henry's constants (KH) and interaction energies were used to analyze the adsorbate–adsorbent interaction strengths and gas uptake of guest molecules. The Qst of CO2 was found to be 1.29–1.73 times higher in MeMOF-1 than in FMOF-1, vs. 1.30–1.47 times for CH4, hence demonstrating higher guest affinity to MeMOF-1 than to the FMOF-1 polymorph. Simulated isotherms were further fitted with Langmuir, Langmuir–Freundlich, and Tóth models to calculate the isosteric heat of adsorption at infinite dilution (Qst0) using the Clausius–Clapeyron equation. The data were then compared with those obtained from force-field-based Monte Carlo (MC) simulations to determine the consistency. The Tóth model presented excellent characterization of CO2 and CH4 adsorption, implying both FMOF-1 and MeMOF-1 materials have inhomogeneous surfaces. The order of the Qst0 values obtained using the Clausius–Clapeyron equation was consistent with that obtained from MC simulations and confirmed the higher uptake of CO2 and CH4 in MeMOF-1 as predicted by GCMC. The presence of H2O vapor, up to 80% relative humidity, did not affect the CO2 and CH4 adsorption in MeMOF-1 structures, as was observed in the analogous FMOF-1 parent structure. The larger pore size and surface area upon substituting −CF3 groups with −CH3 groups allow for significantly greater CO2 and CH4 uptake in MeMOFs compared to FMOFs with no water uptake even at high humidity. These simulations were applied upon MeMOF analogues of multiple FMOF-1 polymorphs known to date and are thus expected to hold for MeMOF analogues of other FMOF and MOFF structures reported by the Omary and Miljanić teams, respectively. Experimental data have validated the superhydrophobic nature of the MeMOF-1 composition via a polymorphic form with a different topology, MeMOF-2, attaining an ∼100° increase in water-drop contact angles, from ∼74° for a control plastic substrate to ∼172° upon dry-coating it with MeMOF-2. Experimentally synthesized MeMOF-2 possesses the same {Ag(3,5-(CH3)2-1,2,4-triazolate)} empirical formula as that of simulated MeMOF-1 structures, albeit with a different crystal structure and lower porosity.