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This work presents a simple protocol that demonstrates the use of an inexpensive household carbon monoxide detector as a useful tool to detect the release of carbon monoxide gas from thermal cheletropic decarbonylation reactions. The carbon monoxide detection method described has been employed in a short series of reactions used in a university teaching laboratory setting, and full procedures for these are outlined. In each case, the procedure to isolate and identify the decarbonylation products has also been provided.

We report the synthesis, characterisation and reactivity of the stable imidazol-2-ylidene EtIDip (EtIPr), {EtCN(Dip)}2C:, Dip = 2,6-iPr2C6H3, as a chemically robust alternative to IDip (IPr), {HCN(Dip)}2C:. The N-heterocyclic carbene EtIDip could be further converted to the oxidised species [EtIDipCl]Cl, EtIDipF2, EtIDipO, and EtIDipSe, and the group 13 element complexes EtIDipEX3, with E = B, X = Br; E = Al, X = I; E = Ga, X = I; E = Al, X = H. The properties of the EtIDip and IDip ligands are compared and the molecular structures of (DipNCEt)2, [EtIDipH]Cl, [EtIDipH]I, EtIDip, [EtIDipCl]Cl, EtIDipF2, EtIDipO, EtIDipBBr3, EtIDipAlI3, EtIDipGaI3, and EtIDipAlH3 have been determined. [ABSTRACT FROM AUTHOR]

Ammonium oxathioamidate (1) was synthesised by the reaction between O-ethyl-thioxamate (oxalic acid-1-amide-2-O-ethyl ester) and ammonium hydrogen carbonate in water solution. Compound 1 was fully characterised by both microanalytical (elemental analysis, melting point determination) and spectroscopic means (FT-IR and NMR spectroscopy). Crystals suitable for single-crystal X-ray diffraction were isolated by slow evaporation of an ethanol solution of the compound. The analysis of the crystal packing reveals the prominent role exerted by intermolecular hydrogen bonding (HB) and chalcogen bonding (ChB) interactions. [ABSTRACT FROM AUTHOR]

Although known for 120 years, the title compound has not been adequately characterised before. In this paper, it is fully characterised by 1H and 13C NMR and IR spectroscopy and its X-ray structure has been determined for the first time. [ABSTRACT FROM AUTHOR]

Nitroxides are stable organic radicals with exceptionally long lifetimes, which render them uniquely suitable as observable probes or polarising agents for spectroscopic investigation of biomolecular structure and dynamics. Radical‐based probes for biological applications are ideally characterized by both robustness towards reductive degradation and beneficial electron spin relaxation parameters. These properties are largely influenced by the molecular structure of the nitroxide scaffold, and also by the conformations it prefers to adopt. In this study we present the synthesis of the first nitroxides based on a spirocyclic pyrrolidine scaffold with an exocyclic methylene substituent. The conformations adopted by these nitroxides were evaluated by X‐ray crystallography, both with single nitroxide crystals and by inclusion of nitroxides in a microporous crystalline sponge. The kinetic and thermodynamic stability of the new nitroxides towards reduction was investigated by electron paramagnetic resonance (EPR) spectroscopy and cyclic voltammetry (CV). In combination with EPR measurements of electron spin relaxation properties, these results suggest that this new family of nitroxides can provide access to multifunctionalized probes and polarising agents suitable for use in biological environments at elevated temperatures. [ABSTRACT FROM AUTHOR]

We have designed a highly twisted small thermally activated delayed fluorescence (TADF) emitter PXZ-[alpha]-DK based on an [alpha]-diketone ([alpha]-DK) as a strong acceptor and phenoxazine (PXZ) as a strong donor to obtain red-shifted emission in comparison with the equivalent [alpha]-diketone linked to 9,9-dimethyl-9,10-dihydroacridine (DMAC). The PXZ-[alpha]-DK shows emission at 586 nm and DMAC-[alpha]-DK shows emission at 548 nm in 1,3-bis(N-carbazolyl)benzene (mCP) host at 1.5 wt% doping of the emitter, with short-delayed lifetimes of 6.9 ls for PXZ-[alpha]-DK and 7.6 ls for DMAC-[alpha]-DK. Organic light-emitting diodes (OLEDs) fabricated using these emitters show green electroluminescence at 555 nm for DMAC-[alpha]-DK, with a maximum external quantum efficiency, [EQE.sub.max], of 6.3%, and orange electroluminescence at 585 nm for PXZ-[alpha]-DK, with an [EQE.sub.max] of 0.8%. We corroborate the optoelectronic properties of these emitters with DFT calculations. Key words: TADF, OLEDs, [alpha]-diketone, red-shifted emission. Nous avons concu un emetteur de fluorescence retardee activee thermiquement (TADF pour Thermally Activated Delayed Fluorescence) a haut degre de torsion, PXZ-[alpha]-DK, a partir d'une [alpha]-dicetone (aDK) comme groupe accepteur fort et de la phenoxazine (PXZ) comme groupe donneur fort pour obtenir une emission deplacee vers le rouge par rapport a l'analogue constitue de l' adicetone liee a la 9,9dimethyl-9,10dihydroacridine (DMAC). La PXZaDK presente une emission a 586 nm et la DMACaDK, une emission a 548 nm dans une matrice hote de 1,3bis(N-carbazolyl)benzene (mCP) a un taux de dopage de l'emetteur de 1,5 % p/p, le temps de vie retarde de courte duree etant de 6,9 ls pour la PXZaDK et de 7,6 ls pour la DMACaDK. Les diodes electroluminescentes organiques (DELO) fabriquees a l'aide de ces emetteurs presentent une electroluminescence verte a 555 nm avec une efficacite quantique externe maximale ([EQE.sub.max]) de 6,3 % dans le cas de la DMACaDK, et une electroluminescence orange a 585 nm avec une [EQE.sub.max] de 0,8 % dans le cas la PXZaDK. Nous corroborons les proprietes optoelectroniques de ces emetteurs par des calculs DFT. [Traduit par la Redaction] Mots-cles : TADF, DELO, [alpha]-dicetone, emission deplacee vers le rouge., Introduction Since the seminal report of Adachi and co-workers in 2012, (1) organic light-emitting diodes (OLEDs) employing organic thermally activated delayed fluorescence (TADF) emitters have received significant attention because of [...]

A laboratory activity is described for senior high school or first year undergraduate level students that illustrates key concepts linked to extractive metallurgy. This experiment demonstrates preferential binding of a methoxyphenolic oxime ligand to Cu[superscript 2+] in the presence of other transition metal ions in aqueous solution. The students are tasked to investigate the importance of the spatial relationship between the oxime and phenol group of two potential ligands by performing a series of short and simple tests. The objective is achieved by identifying which methoxyphenolic oxime ligand selectively and rapidly forms an isolable precipitate with Cu[superscript 2+] ions. Only one of the potential ligands exhibits a clear preference for binding to Cu[superscript 2+], and this can easily be identified visually (and confirmed by UV-visible spectroscopy if desired). The experiment has successfully been employed as part of an extracurricular laboratory course involving groups of 25-30 high school students.

The development of methods for the selective acylative kinetic resolution (KR) of tertiary alcohols is a recognised synthetic challenge with relatively few successful substrate classes reported to date. In this manuscript, a highly enantioselective isothiourea‐catalysed acylative KR of tertiary pyrazolone alcohols is reported. The scope and limitations of this methodology have been developed, with high selectivity observed across a broad range of substrate derivatives incorporating varying substitution at N(2)‐, C(4)‐ and C(5)‐, as well as bicyclic constraints within the pyrazolone scaffold (30 examples, selectivity factors (s) typically >100) at generally low catalyst loadings (1 mol %). The application of this KR method to tertiary alcohols derived directly from a natural product (geraniol), alongside pharmaceutically relevant drug compounds (indomethacin, gemfibrozil and probenecid), with high efficiency (s >100) is also described. The KR process is readily amenable to scale up using bench grade solvents and reagents, with effective resolution on a 50 g (0.22 mol) scale demonstrated. The key structural motif leading to excellent selectivity in this KR process has been probed through computation, with an NC=O⋅⋅⋅isothiouronium interaction from substrate to acylated catalyst observed within the favoured transition state. Similarly, the effect of C(5)‐aryl substitution that leads to reduced experimental selectivity is probed, with a competitive π–isothiouronium interaction identified as leading to reduced selectivity. [ABSTRACT FROM AUTHOR]

Multi‐resonant thermally activated delayed fluorescence (MR‐TADF) helicenes show great potential as chiral emitters due to their typically high photoluminescence quantum yield and that they emit circularly polarized luminescence. Here, a new propeller‐shaped chiral MR‐TADF helicene DiKTa3, integrating three DiKTa moieties, was designed and synthesized aiming to achieve co‐parallel electronic and magnitude transition dipole moments that would lead to a high dissymmetry factor, g. It emits at λPL of 491 nm, with a full width at half maximum of 52 nm and has a moderate ΔEST value of 0.24 eV in toluene. The separated (P,P,P) enantiomer shows an absorption dissymmetry factor |gabs| of 6.8×10−4 at 450 nm, which results from a lower symmetry conformation adopted by the compound in solution than the C3‐symmetric optimized structure. This work highlights the strong influence that geometry can have on the chiroptical properties of the emitter. [ABSTRACT FROM AUTHOR]

ABSTRACT Tin complexes, Sn(IV)‐TSC 1·MeOH and Sn(IV)‐TSC 2, with thiosemicarbazones possessing an N2S ligation system [TSC 1 = 4‐(4‐nitrophenyl)‐1‐((pyridin‐2‐yl)methylene)thiosemicarbazide and TSC 2 = 4‐(2‐methoxyphenyl)‐1‐((pyridin‐2‐yl)methylene)thiosemicarbazide] were prepared and structurally characterized. These complexes are found in the space groups P1¯$$ \overline{1} $$ and P21/n, respectively, with their tin atoms in octahedral environments established by three chlorine atoms and an anionic thiosemicarbazone ligand. All compounds (20 mg/mL in DMSO) were tested for their antibacterial [against Bacillus subtilis, Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa] and antifungal [against Aspergillus flavus and Candida albicans] properties. The ligand TSC 2 displayed inhibitions in the S. aureus and E. coli cultures (with zones of 11 and 10 mm, respectively), whereas Sn(IV)‐TSC 1·MeOH and Sn(IV)‐TSC 2 inhibited all bacteria with 11–15 and 14–16 mm, respectively. In the fungal cultures, only Sn(IV)‐TSC 1·MeOH (10 mm) showed an inhibition zone against A. flavus. The ligands' antiproliferative activities were determined against human cancer cells of the lung, breast, liver, and colon, and both ligands afforded the highest activity against the breast MCF‐7 cells. The complexation enhanced the ligands' activities as TSC 1, TSC 2, Sn(IV)‐TSC 1·MeOH, and Sn(IV)‐TSC 2 afforded respective IC50 values of 52.4, 153.7, 18.3, and 63.9 μM. However, against normal baby hamster kidney (BHK) cells, these compounds showed IC50 data of 54.8, 82.7, 16.1, and 15.3 μM, respectively. [ABSTRACT FROM AUTHOR]

A route is developed to (γ,γ',γ"'‐trifluoro)neopentyl (TFNP) aryl ethers to extend the methods for the introduction of the tert‐butyl group, carrying a fluorine on each of the methyl substituents. The route combines neopentyltosylate 3 with phenols and thiophenols to give efficient substitution reactions to the corresponding TFNP aryl ethers. The three C−F bonds adopt a helical propeller conformation as revealed by computation and single crystal X‐ray structure analysis. The LogPs of TFNP ethers are lower (more hydrophilic) than their neopentyl analogues. The metabolism of selected TFNP ethers was explored in the fungus Cunninghamella elegans. [ABSTRACT FROM AUTHOR]

Controlling and understanding charge state and metal coordination in carbon nanomaterials is crucial to harnessing their unique properties. Here we describe the synthesis of the well‐defined fulleride complex [{(Mesnacnac)Mg}6C70], 2, (Mesnacnac)=HC(MeCNMes)2, Mes=2,4,6‐Me3C6H2, from the reaction of the β‐diketiminate magnesium(I) complex [{(Mesnacnac)Mg}2] with C70 in aromatic solvents. The molecular structure of complex 2 was determined, providing the first high‐quality structural study of a complex with the C706− ion. In combination with solution state NMR spectroscopic and DFT computational studies, the changes in geometry and charge distribution in the various atom and bond types of the fulleride unit were investigated. Additionally, the influence of the (Mesnacnac)Mg+ cations on the global and local fulleride coordination environment was examined. [ABSTRACT FROM AUTHOR]

A general and highly enantioselective method for the preparation of tetra‐substituted 3‐hydroxyphthalide esters via isothiourea‐catalysed acylative dynamic kinetic resolution (DKR) is reported. Using (2S,3R)‐HyperBTM (5 mol %) as the catalyst, the scope and limitations of this methodology have been extensively probed, with high enantioselectivity and good to excellent yields observed (>40 examples, up to 99 %, 99 : 1 er). Substitution of the aromatic core within the 3‐hydroxyphthalide skeleton, as well as aliphatic and aromatic substitution at C(3), is readily tolerated. A diverse range of anhydrides, including those from bioactive and pharmaceutically relevant acids, can also be used. The high enantioselectivity observed in this DKR process has been probed computationally, with a key substrate heteroatom donor O⋅⋅⋅acyl‐isothiouronium interaction identified through DFT analysis as necessary for enantiodiscrimination. [ABSTRACT FROM AUTHOR]

The development of methods to allow the selective acylative dynamic kinetic resolution (DKR) of tetra‐substituted lactols is a recognised synthetic challenge. In this manuscript, a highly enantioselective isothiourea‐catalysed acylative DKR of tetra‐substituted morpholinone and benzoxazinone‐derived lactols is reported. The scope and limitations of this methodology have been developed, with high enantioselectivity and good to excellent yields (up to 89 %, 99 : 1 er) observed across a broad range of substrate derivatives incorporating substitution at N(4) and C(2), di‐ and spirocyclic substitution at C(5) and C(6), as well as benzannulation (>35 examples in total). The DKR process is amenable to scale‐up on a 1 g laboratory scale. The factors leading to high selectivity in this DKR process have been probed through computation, with an N−C=O⋅⋅⋅isothiouronium interaction identified as key to producing ester products in highly enantioenriched form. [ABSTRACT FROM AUTHOR]

The title compound and its hydroxymethyl precursor have been fully characterised for the first time. The IR spectra, fully assigned 1H and 13C NMR spectra, and X-ray structures are presented for both compounds. Both compounds form hydrogen-bonded dimers in the crystal structures. [ABSTRACT FROM AUTHOR]

X-ray crystallography has been used to characterize the title compound for the first time; 1H NMR, 13C NMR and IR spectroscopic data have also been updated from earlier reports. We also report the melting point of the title compound. [ABSTRACT FROM AUTHOR]

The bidentate ligand, 1,4-bis(diphenlyphosphoryl)butane (dppbO2), was used to prepare a 1D polymeric Pr(III) complex which was characterised by single-crystal X-ray diffraction. [ABSTRACT FROM AUTHOR]

Two salts of the chlorhexidine di-cation (H2CHx2+) - (H2CHx)(SO4)·3H2O and (H2CHx)(CO3)·4H2O - have been synthesised and characterised crystallographically.