Chiral non-heme iron(IV)-oxo complexes supported by amidecontaining PDP (N,N′-bis(pyridin-2-ylmethyl)-2,2′-bipyrrolidine) ligands were generated from their iron(II) precursors and characterised spectroscopically. The role of the amide functionality in tuning the stability of...
Herein, we report the monoanionic N, N’-chelated biguanidinate-supported thioxoborane and selenoxoborane, XylLB=S (1) and XylLB=Se (2) (L = {(ArHN)(ArN)–C=N–C=(NAr)(NHAr)}; Ar = Xyl = 2,6-Me2-C6H3). These compounds are synthesized by treating...
Shallow tissue penetration of excitation light remains the most persistent barrier to effective photodynamic therapy (PDT), compounded further by tumour hypoxia and elevated glutathione (GSH). Herein, we report a rationally...
Voloxidation has long been investigated as a front-end treatment for used nuclear fuel recycling. The primary objectives of this treatment include fuel decladding, oxidation-induced pulverization, and consolidated volatile fission product...
Perovskite-type SrVO 3 is a promising candidate for indium-free transparent conducting oxides.High carrier conductivity and transparency are key factors for high-performance transparent conducting oxides. In this study, we report a simple...
Transition metal sulfides can be controllably transformed into (oxy)hydroxides, offering a promising route to efficient OER electrocatalysts. However, understanding how residual sulfur tunes intrinsic activity remains a challenge. Herein, a mild H2O2-controlled oxidation strategy is developed to tailor surface sulfur residues on cobalt-iron sulfides, yielding high-performance sulfur-doped (oxy)hydroxide catalysts. By tuning the oxidation time, a non-monotonic relationship between residual sulfur content and OER activity is observed. The optimal catalyst reduces the overpotential by 41 mV to 243 mV at 10 mA cm-2 and operates stably for 120 h. Mechanistic studies reveal that an appropriate residual sulfur level enhances the OER kinetics by downshifting the d-band center to optimize intermediate adsorption, while simultaneously lowering the work function and increasing carrier density to accelerate interfacial charge transfer. Excessive sulfur removal degrades performance. This work offers a new perspective for designing OER electrocatalysts through rational regulation of surface residual species.
We demonstrate selective and direct platinum-mediated insertion of a nitrile fragment into the C–N bond of a pyridinium amidate scaffold. This reactivity expands the ligand skeleton through insertion of two...
Cadmium antimonite system is expected to become a promising candidate for exploring novel optical functional crystal materials, owing to the synergistic effect of d10 transition metal and lone pair electrons....
Molecular ferroelectric materials have garnered profound interest in the last two decades owing to their structural flexibility, tunability, and homochirality, enabling a variety of technological applications. Achieving polar point groups...
A novel nitrogen-rich cationic precursor (Compound 2) was designed and synthesized by linking an acetimidamide moiety with a 5-aminotetrazole. In contrast to conventional 5-aminotetrazole-derived energetic compounds, which typically form energetic...
β-Diketiminate (BDI)-supported zinc complexes are among the most efficient initiators for the ring-opening polymerization (ROP) of β-butyrolactone (BBL), but their application in high-temperature bulk polymerization is limited by initiator deactivation. To improve thermal robustness, a new BDI-supported zinc initiator incorporating a 2,6-bis(diphenylmethyl)-4-methylphenyl substituent was designed, synthesized, and structurally characterized. Compared with a conventional BDI-supported zinc initiator, the new complex exhibits superior performance in the bulk polymerization of BBL at elevated temperatures, affording colorless poly(3-hydroxybutyrate) (PHB) with number-average molecular weights up to 187 000 g mol-1 under solvent-free conditions. The enhanced polymerization performance is attributed to improved thermal robustness arising from the suppression of initiator deactivation during high-temperature polymerization.
The coordination chemistry of the fluorinated, B-methylated tris(pyridyl)borate ligand with coinage-metal centers Cu(I), Ag(I), and Au(I) bearing triphenylphosphine and tert-butyl isocyanide co-ligands is described. The complexes [MeB(6-(CF3)Py)3]M(PPh3) and [MeB(6-(CF3)Py)3]M(CNtBu) were synthesized in good yields and fully characterized by multinuclear NMR and IR spectroscopy, as well as single-crystal X-ray diffraction. The tris(pyridyl)borate ligand exhibits systematic variations in denticity governed by both the metal center and the ancillary ligand. Bulky PPh3 enforces κ2 coordination in trigonal-planar Cu(I) and Ag(I) complexes, but κ1 coordination in linear Au(I) species. In contrast, the smaller CNtBu ligand enables κ3 coordination, affording tetrahedral Cu(I) and Ag(I) complexes and a pseudo-κ2, distorted T-shaped Au(I) derivative. Together with previously reported CO (κ3) and ethylene (κ2) analogs, these findings demonstrate that the steric and electronic properties of the terminal ligand effectively modulate binding modes across the coinage-metal triad. Some of the fluorinated systems exhibit informative through-space 31P-19F and Ag-F NMR couplings. Density functional theory (DFT) and energy decomposition analysis using natural orbitals for chemical valence (EDA-NOCV) reproduce the observed structures and indicate that the interactions are predominantly electrostatic. These results establish [MeB(6-(CF3)Py)3]- as a robust and versatile platform with flexible coordination modes for tuning coordination environments in coinage-metal complexes.
Reflection at glass/air interfaces remains a major source of optical loss in transparent optoelectronic devices, which can be effectively mitigated by introducing antireflective coatings based on low-refractive-index materials. Calcium fluoride (CaF2) is an excellent candidate due to its intrinsically low refractive index, broad spectral transparency and outstanding stability; however, its solution processing using environmentally benign solvents has remained challenging. Here, we report a room-temperature synthetic route to ethanol-dispersible CaF2 nanocrystals with an average size of 4.2 nm. These nanocrystals can be readily spin-coated onto glass substrates to form continuous films with a low refractive index of 1.41, which significantly increase the average transmittance of the coated glass from 93.3% to 95.9% over the 400-1000 nm wavelength range, corresponding to an overall enhancement of 2.6%. This work establishes a simple and effective surface-ligand engineering strategy that bridges room-temperature colloidal synthesis with ethanol-based processing, offering a low-cost and scalable route to high-performance antireflective coatings for applications in light-emitting diodes, thin film solar cells and photodetectors.
Hydrazine is reacted with main group Lewis acids including those with LUMOs derived from either vacant p-orbitals, or low lying σ* orbitals and of varying Lewis acidities. This is shown to give a diverse range of resulting products. For Lewis acids with vacant 2p-orbitals such as the boranes, BF3, Mes2BH, MesBH2, PhBBN, and C6F5BBN reacts with hydrazine gave the Lewis acid-base mono- and bis-adducts (F3B)2(N2H4) 1, Mes2BH(NH2NH2) 2, MesBH2(NH2NH2) 3, (PhBBN)2(NH2NH2) 4, and (C6F5BBN)NH2NH25, respectively. In contrast, the reaction of the 3p-Lewis acid [Et3Si(HSiEt3)]+ showed no evidence of Si-hydrazine coordination. Rather, the hydrazinium salt [(NH2NH2)2H][B(C6F5)4] 6 was obtained and prepared independently via reaction with triflic acid and subsequent anion exchange. Reaction of GaCl3 (a 4p-Lewis acid) with hydrazine afforded the polymeric species [Cl3GaNH2NH2]n7. The phosphonium bromides [R3PBr]Br (R = Ph, Et) are σ*-derived Lewis acids and react with hydrazine to afford the salts, [Ph3PNHNH2]Br 8 and [(Ph3PNH)2]X2 (X = Br 9, GaCl410) and [(Et3PNH)2]Br211 respectively. In contrast, the corresponding reaction of [(C6F5)3PCl]Cl afforded (H2NNHC6F4)3PO 12 which exhibited an extended H-bonding network structure in the solid state. These products of the reactions of Lewis acids with hydrazine are documented and the range of structural features discussed.
The rational design of graphene-supported single-atom catalysts (SACs) requires maximizing metal utilization while ensuring structural stability, yet the underlying principles remain fragmented across the literature. Here we present a systematic DFT study of 60 SACs comprising first-row transition metals anchored to mono- and divacancy graphene supports, with and without nitrogen doping, and complemented by Ni(111)-supported metallic systems. By decomposing metal adsorption into deformation and intrinsic binding contributions, we distinguish structural from electronic metrics that contribute to the stability of these systems. Divacancies provide significantly stronger and more flexible coordination environments than monovacancies, and carbon coordination consistently outperforms nitrogen coordination regarding the metal-graphene bond. Across the transition-metal series, stability is primarily governed by the alignment between metal d states and the graphene Fermi level, further modulated by radius-dependent geometric accommodation. For the later transition metals, nitrogen doping weakens binding by partially filling antibonding states. Meanwhile, incorporation on a Ni(111) support enhances metal anchoring in divacancies but weakens it in monovacancies, while preserving the overall trends observed for unsupported systems. Magnetization and charge transfer are strongly correlated with the metal-graphene binding energies. Together, these trends define a categorical framework that intertwines the tendencies of vacancy topology, coordination chemistry, and electronic alignment. This understanding provides crucial insights for engineering robust graphene-based SACs and offers a basis for pre-selecting experimentally viable candidates.
DFT guided unsupported intermetallics NiIn 1− x Sn x ( x = 0.5, 0.8) synthesized via high temperature method. Hexagonal NiIn 0.5 Sn 0.5 has higher activity and selectivity towards ethylene for acetylene hydrogenation reaction than orthorhombic NiIn 0.2 Sn 0.8 .
Crown-ether-coordination compounds of praseodymium(III), manganese(II) and the crown ether 18-crown-6 ((C2H4O)6, 18c6) are prepared in [Bu3MeN][NTf2] ([Bu3MeN]+/[(C4H9)3(CH3)N]+: tributylmethylammonium; [NTf2]-/[(CF3SO2)2N]-: bis(trifluoromethylsulfonyl)amide) as an ionic liquid. Specifically, the reaction of PrCl3, PrI3, MnCl2 or MnI2 with 18c6 at 80-100 °C results in the novel compounds [PrCl3(18c6)] (1), [MnCl2(18c6)] (2), [Bu3MeN][PrI2(18c6)][MnI4] (3), [Bu3MeN]2[MnI4] (4), [Bu3MeN]2[(Pr(I0.82Cl0.18)Cl(18c6))2][MnI4]2 (5) and [(PrCl2(18c6)MnI3)2] (6). They contain mononuclear arrangements of Pr3+ (1) and Mn2+ (2) with 18c6. 3 and 5 contain both Pr3+ and Mn2+ in a single compound but in different molecular building units ([PrI2(18c6)]+, [(Pr(I0.82Cl0.18)Cl(18c6))2]+, and [MnI4]2-) with a great distance between them (Pr-Mn > 700 pm). Finally, 6 represents the first crown-ether coordination compound with Pr3+ and Mn2+ in a single tetranuclear molecule. All title compounds are characterized by X-ray diffraction (single crystals, powder diffraction with Rietveld analysis), infrared spectroscopy, thermal analysis, and photoluminescence spectroscopy. 2-5, even when containing Pr3+ (3 and 5), show typical luminescence of Mn2+, whereas 1 and 6 show Pr3+-type transitions, with 6 showing particularly intense emission. Pr3+ → Mn2+ energy transfer is not observed, which can be ascribed to the specific distances between the luminescent centers (3 and 5) or the symmetry of the molecule (6).
Super-oxidized porous carbon (SOPC) synthesized starting from spruce cones is demonstrated as an efficient sorbent for two lanthanide elements (Ce and Yb) from their nitrate solutions. Strong oxidation treatment applied to activated carbon with an extremely high BET surface area (∼3400 m2 g-1) resulted in the synthesis of carbon material with an oxidation degree on the same level as graphene oxide (C/O = 2.1), a nanoporous structure with rather narrow pore size distribution and a relatively large BET surface area of ∼1200 m2 g-1. Despite the decrease in surface area, hydrophilic SOPC demonstrates strong enhancement of Ce and Yb uptake reaching the level of 140-170 mg g-1, about 20-25 times higher compared to the hydrophobic non-oxidized activated carbon precursor under the same conditions. Analysis of advanced synchrotron radiation X-ray spectroscopy data allows us to assign the increase in sorption of metal cations to a high abundance of oxygen functional groups double-bonded to carbon. These groups are mostly located at generalized "pore edges" or vacancy defects in the atomically thin carbon walls of SOPC according to modelling of X-ray Raman scattering (XRS) spectra at the carbon K edge. Surprisingly, effects of nano-confinement are not revealed by the analysis of extended X-ray absorption fine structure (EXAFS) spectra at the Yb L3 edge, suggesting that Ce and Yb cations are accommodated at the entrance sites of sub-nm-sized pores of SOPC in the hydrated state while maintaining an oxidation state found in the solutions. The SOPC enables the removal of up to 99% of Ln from solutions with a concentration of 10 mg L-1 of Yb or Ce. Further increases in sorption capacity are likely to be possible if larger portions of the surface area can be preserved after similarly strong oxidation treatment.
N-directed borylation of polycyclic aromatic hydrocarbons (PAHs) is emerging as a versatile approach to the synthesis of novel photoactive materials for optoelectronic, imaging, sensing, and photocatalysis applications. We show here that while the N-directed bis-borylation of N,N-dipyridyl-N,N-dihydrophenazine (Pz) predominantly produces a B-N-fused cis-isomer with both boryl groups attached to the same benzene ring, the trans-isomer is also generated as a minor component. We report the isolation and detailed characterization of cis-BNPz and trans-BNPz, as well as a mono-functionalized intermediate, mono-BNPz. The optical and electronic properties of the regioisomers are compared. In addition, computational studies shed light on the reaction pathways involved, offering insights into the origin of regioselectivity and revealing a process that proceeds without an external base.
Lanthanide(III) complexes combine unique magnetic and photophysical features that are highly sensitive to their coordination environment. While β-diketonate ligands with oxygen donors are widely employed in designing singlemolecule magnets and...
