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Scorpionate ligands have emerged as pivotal components in the field of coordination chemistry and catalysis since the seminal work by Trofimenko in the late 1960s. These species have demonstrated an extraordinarily rich tridentate coordination chemistry, enhancing the stability of metal complexes. In addition, they offer the possibility of modifying the chemical and electronical features as κ3-ligands, providing a wide variety of potential substrates with multiple donor atoms. Furthermore, this type of ligand has shown wide versatility in its coordination mode and can adopt different binding arrangements, expanding its potential as a universal ligand. This review provides a comprehensive overview of the main advances in exploring scorpionate complexes based on the tris(1H-pyrazol-1-yl)borate and bis(1H-pyrazol-1-yl)methane moieties, which have been recently reported as efficient catalysts for the synthesis of sustainable polymers. Specifically, this work focuses on the preparation of biorenewable polylactides (PLAs), other polyesters and polycarbonates (PCs), derived from cyclohexene carbonate, polylactide-co-polycarbonate copolymers and alternative sustainable polymeric materials. Thus, we have faced this challenge by selecting and classifying the most well-performed scorpionate catalyst system, including divalent (magnesium, calcium, zinc and iron) and other metals (rare-earth metals and zirconium), for each of the catalytic processes mentioned above. This review represents the first contribution that summarises and illustrates the current state of the art related to the use of scorpionate-based systems as efficient catalysts for the preparation of sustainable polymer materials. This account finally aims to guide future research towards the development of more eco-friendly catalytic processes in promoting sustainable polymers to achieve relevant commodities. [ABSTRACT FROM AUTHOR]

Literature on Group One organoelement chemistry is dominated by lithium, though sodium and potassium also feature prominently, whereas rubidium and caesium are rarely mentioned. With recent breakthroughs hinting that organoelement compounds of these two heavier metals can perform better than their lighter congeners in particular applications, important advantages could be missed unless complete sets of alkali metals are included in studies. Here, we report the synthesis and characterisation of a complete set of multi‐alkali‐metallated molecular compounds of the 1,3,5‐tris[(4,6‐dimethylpyridin‐2‐yl)aminomethyl]‐2,4,6‐triethylbenzene framework. Made by deprotonating the framework N−H bonds by a suitable base, the set comprises six THF‐solvated compounds, four of which are homometallic, either containing Li in a trinuclear structure or Na, K, and Rb in hexanuclear structures. Since deprotonation was incomplete with Cs, its homometallic compound is tetranuclear containing two un‐metallated N−H bonds. A heterobimetallic trilithium‐tricaesium hexanuclear compound was also obtained by using a bimetallic Li−Cs base for deprotonation. Such alkali‐metallated frameworks are often precursors to other multimetallic frameworks with unique properties across different fields of science. [ABSTRACT FROM AUTHOR]

Background: Chemical debridement is a fundamental step during the surgical treatment of both acute and chronic periprosthetic joint infection (PJI). However, there is no consensus on the optimal solution, nor is there sufficient evidence on the optimal irrigation time and combination of solutions. In an in vitro study, our group recently demonstrated that sequential combination debridement (SCD) with 3% acetic acid (AA) followed by 10% povidone iodine (PI) and 5 mM hydrogen peroxide (H2O2) was the best strategy for reducing bacterial load. The present study aimed to validate these findings in an in vivo model. Results: The median (IQR) log CFU/mL was lower in the group of mice treated with SCD (2.85 [0.00–3.72]) than in the Bactisure™ group (4.02 [3.41–4.72], p = 0.02). While this reduction was also greater than in the PI group (3.99 [1.11–4.33]), the difference did not reach statistical significance (p = 0.19). Cell viability assays showed no differences between treatments. S. aureus bacteremia was detected in 10% of mice treated with SCD, compared to 30% in the PI group and 10% in the Bactisure™ group. The difference was not statistically significant (p = 0.36). Conclusion: Our findings confirm that SCD significantly reduced bacterial load in an in vivo S. aureus PJI model, showing superior anti-biofilm activity compared to Bactisure™ and comparable performance to PI alone. These results highlight SCD's potential to serve as a standardized chemical debridement protocol, combining enhanced efficacy with clinical applicability. Methods: We tested SCD with 3% AA for 3 min, 10% PI for 3 min, and H2O2 for 3 min in a 7-day Staphylococcus aureus (ATCC29213)-based murine femur PJI model and compared the results with single treatments of 10% PI for 3 min or Bactisure™ solution for 3 min. A sterile steel implant with local administration of saline solution for 3 min was used as a non-infected control. After completing irrigation procedures, under anesthesia, mice were euthanized, and implants were analyzed for CFU/mL counts and cell viability rates. Blood cultures were obtained pre-euthanasia to detect bacteremia. [ABSTRACT FROM AUTHOR]

New and simple ligand design strategies for the preparation of versatile metal-based catalysts capable of operating under greener and eco-friendly conditions in several industrially attractive processes are in high demand for society development. We present the first nucleophilic addition of an organolithium to ketenimines which incorporates a stereogenic centre in an N-donor atom to prepare new enantiopure NNN-donor scorpionates. We have also verified its potential utility as a valuable scaffold for chirality induction through the preparation of inexpensive, non-toxic and asymmetric zinc complexes. The pro-ligands and the corresponding zinc-based complexes have been characterized by X-ray diffraction studies. DFT studies were carried out to rationalize the different complexation abilities of these pro-ligands. These complexes have proved to act as highly efficient catalysts for a variety of sustainable bioresourced processes that are industrially attractive, with a wide substrate scope. Thus, complex 7 behaves as a highly efficient initiator for the well-behaved living ring-opening polymerization (ROP) of rac-lactide under very mild conditions. The PLA materials produced exhibited enhanced levels of isoselectivity, comparable to the highest value reported so far for zinc-based catalysts (Pi = 0.88). In addition, the combination of 7 with onium halide salts functioned as a very active and selective catalyst for CO2 fixation into five-membered cyclic carbonates through the cycloaddition of CO2 into epoxides under very mild and solvent-free conditions, reaching very good to excellent conversions (TOF = 227 h−1). Furthermore, this bicomponent system exhibits a broad substrate scope and functional group tolerance, including mono- and di-substituted epoxides, as well as the very challenging bio-renewable tri-substituted terpene-derived cis/trans-limonene oxide, whose reaction proceeds with high stereoselectivity. Finally, complex 7 also achieved high activity and selectivity as a one-component initiator for the synthesis of poly(cyclohexene carbonate)s via ring-opening copolymerization (ROCOP) of cyclohexene oxide and CO2 under very soft conditions, affording materials with narrow dispersity values. [ABSTRACT FROM AUTHOR]