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Rotaxanes can be regarded as storage systems for their wheel components, which broadens their application potential as a complement to the supramolecular systems that retain a mechanically interlocked structure. However, utilising rotaxanes in this way requires a method to release the wheel while preserving the integrity of all molecular constituents. Herein, we present simple rotaxanes based on cucurbit[6]uril (CB6), with an axis equipped with an additional binding motif that enables the binding of another macrocycle, cucurbit[7]uril (CB7). We demonstrate that the driving force behind the wheel dethreading originates from the binding of the signalling macrocycle to the allosteric site, leading to an increase in the system's strain. Consequently, the CB6 wheel leaves the rotaxane station overcoming the mechanical barrier. Portal-portal repulsive interactions between the two cucurbituril units play a crucial role in this process. Thus, the repulsive strength and the related rate of slipping off can be finely tuned by the length of the allosteric binding motif. Finally, we show that the CB6 wheel can be utilised within complexes with other guests in the mixture once released from the rotaxane., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)

Starting from N-acyl sulfonimidamides, mechanochemically generated rhodium nitrenoids undergo intramolecular N-O couplings to provide unprecedented 1,3,2,4-oxathiadiazole 3-oxides in good to excellent yields. The cyclization proceeds efficiently with a catalyst loading of only 0.5 mol % in the presence of phenyliodine(III) diacetate (PIDA) as oxidant. Neither an inert atmosphere nor additional heating is required in this solvent-free procedure. Under heat or blue light, the newly formed five-membered heterocycles function as nitrene precursors reacting with sulfoxides as exemplified by the imidation of dimethyl sulfoxide., (© 2024 The Authors. Angewandte Chemie International Edition published by Wiley-VCH GmbH.)

Decades of disaster research support the influence parents have on their children's adaptation. Recently, research has shifted to focus on disasters as a whole family experience. Using the actor-partner interdependence model, this study examines maladaptive cognitive emotion regulation strategies in parents and children and how these strategies influence their own and one another's posttraumatic stress symptoms (PTSS). The present study includes 485 parent-child dyads who experienced the 2015-2016 Texas floods. The majority of parents identified as mothers (66.3%), with a male child (52.8%) whose average age was 13.75 years. Mplus was used to identify the models and evaluate differences between each cognitive emotion regulation strategy across parent-child dyads in the high disaster exposure group compared to all other levels of exposure (other-exposure). Odds ratios examined differences not captured by the actor-partner interdependence model. Support for interdependence was found for the other-exposure group, suggesting parents and children mutually influence each other's PTSS by their own cognitive emotion regulation. No interdependence was found in the high-exposure group. However, high-exposure child actor effects were found for self-blame and other-blame, and child partner effects were only found for self-blame. Parent actor effects were only significant for catastrophizing and parent partner effects for catastrophizing and rumination. Odds ratios for the high-exposure group found that only child self-blame influenced parent PTSS, and only parent rumination and catastrophizing influenced child PTSS. Implications for supporting families after disasters are discussed. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

An adaptable Fe(II) tetrahedral cage, [Fe 4 L 4 ][BF 4 ] 8 (L=tris(4-(((E)-pyridin-2-ylmethylene)amino)phenyl) phosphate), has been synthesised via self-assembly. By modulating the orientation of its pendant P=O groups, the cage was found to be capable of encapsulating anionic, neutral, and cationic guests, which were confirmed in the solid state via single-crystal X-ray diffraction (SCXRD) and in solution by high-resolution mass spectroscopy (HR-MS), as well as by NMR ( 1 H, 19 F, 31 P) studies where possible., (© 2024 The Author(s). Chemistry - A European Journal published by Wiley-VCH GmbH.)

There are several binding groups used within molecular electronics for anchoring molecules to metal electrodes (e.g., R-SMe, R-NH 2 , R-CS 2 - , R-S - ). However, some anchoring groups that bind strongly to electrodes have poor/unknown stability, some have weak electrode coupling, while for some their binding motifs are not well defined. Further binding groups are required to aid molecular design and to achieve a suitable balance in performance across a range of properties. We present an in-depth investigation into the use of carbodithioate esters as contact groups for single-molecule conductance measurements, using scanning tunnelling microscopy break junction measurements (STM-BJ) and detailed surface spectroscopic analysis. We demonstrate that the methyl carbodithioate ester acts as an effective contact for gold electrodes in STM-BJ measurements. Surface enhanced Raman measurements demonstrate that the C=S functionality remains intact when adsorbed on to gold nanoparticles. A gold(I) complex was also synthesised showing a stable C=S→Au I interaction from the ester. Comparison with a benzyl thiomethyl ether demonstrates that the C=S moiety significantly contributes to charge transport in single-molecule junctions. The overall performance of the CS 2 Me group demonstrates it should be used more extensively and has strong potential for the fabrication of larger area devices with long-term stability., (© 2024 The Authors. Angewandte Chemie International Edition published by Wiley-VCH GmbH.)

Halogen(I) complexes are widely used as halogenation reagents and traditionally feature homoleptic stabilising Lewis bases, though the recent revitalisation of iodine(I) carboxylate chemistry has provided isolable examples of heteroleptic iodine(I) complexes. This work reports iodine(I) pnictogenate complexes stabilised by a Lewis base (L), Ph 2 P(O)O─I─L, synthesised via cation exchange from the silver(I) precursor, (Ph 2 P(O)OAg) n . The complexes were characterised in both solution ( 1 H, 1 H- 15 N HMBC, 31 P) and the solid state, and supplemented computationally by DFT studies. Interestingly, these iodine(I) pnictogenates demonstrate a range of stabilities, and have been found to excel as iodination reagents in comparison to carbonyl hypoiodites, with comparable reactivity to the eponymous Barluenga's reagent in the iodination of antipyrine., (© 2024. The Author(s).)

Based on the prior observation of the trifluoroacetate hypoiodite, CF 3 C(O)OI, demonstrating the largest σ-hole of a neutral halogen bond donor, a series of mono- and bis-carbonyl hypoiodites utilising trifluoromethyl or fluorine substituents at various positions of a parent benzoyl skeleton have been synthesised. The carbonyl hypoiodite complexes were prepared via cation exchange of the silver(I) cations with iodine(I) from the respective silver(I) carboxylates and dicarboxylates as the synthetic precursors. A range of pyridinic Lewis bases of varying nucleophilicities were used to stabilise the carbonyl hypoiodites to further probe their properties. The silver(I) intermediates with these Lewis bases were also isolated for silver(I) pentafluorobenzoate, providing additional insight into the cation exchange reaction. All complexes were characterised both in solution ( 1 H, 1 H- 15 N HMBC, 19 F) and in the solid state (SCXRD), permitting insights into the formation of the elusive pyridine-iodine(I) cation., (© 2024 The Authors. Chemistry - An Asian Journal published by Wiley-VCH GmbH.)

The coordination nature of 2-mono- and 2,6-disubstituted pyridines with electron-withdrawing halogen and electron-donating methyl groups for [N-X-N] + (X=I, Br) complexations have been studied using 15 N NMR, X-ray crystallography, and Density Functional Theory (DFT) calculations. The 15 N NMR chemical shifts reveal iodine(I) and bromine(I) prefer to form complexes with 2-substituted pyridines and only 2,6-dimethylpyridine. The crystalline halogen(I) complexes of 2-substituted pyridines were characterized by using X-ray diffraction analysis, but 2,6-dihalopyridines were unable to form stable crystalline halogen(I) complexes due to the lower nucleophilicity of the pyridinic nitrogen. In contrast, the halogen(I) complexes of 2,6-dimethylpyridine, which has a more basic nitrogen, are characterized by X-crystallography, which complements the 15 N NMR studies. DFT calculations reveal that the bond energies for iodine(I) complexes vary between -291 and -351 kJ mol -1 and for bromine between -370 and -427 kJ mol -1 . The bond energies of halogen(I) complexes of 2-halopyridines with more nucleophilic nitrogen are 66-76 kJ mol -1 larger than those of analogous 2,6-dihalopyridines with less nucleophilic nitrogen. The experimental and DFT results show that the electronic influence of ortho-halogen substituents on pyridinic nitrogen leads to a completely different preference for the coordination bonding of halogen(I) ions, providing new insights into bonding in halogen(I) chemistry., (© 2023 The Authors. Chemistry - A European Journal published by Wiley-VCH GmbH.)

The new bis(alkynyl)mercurial Hg{CCSeCW(CO) 2 (Tp*)} 2 (Tp* = tris(dimethylpyrazolyl)borate) forms adducts with fluoride and phenathroline, the structures of which are interpreted in the context of two-coordinate mercury presenting a σ-torroid for spodium bonding.

The nature of (imide)N-X⋯N(pyridine) halogen-bonded complexes formed by six N-haloimides and sixteen 2-substituted pyridines are studied using X-ray crystallography (68 crystal structures), Density Functional Theory (DFT) (86 complexation energies), and NMR spectroscopy (90 association constants). Strong halogen bond (XB) donors such as N-iodosuccinimide form only 1:1 haloimide:pyridine crystalline complexes, but even stronger N-iodosaccharin forms 1:1 haloimide:pyridine and three other distinct complexes. In 1:1 haloimide:pyridine crystalline complexes, the haloimide's N─X bond exhibits an unusual bond bending feature that is larger for stronger N-haloimides. DFT complexation energies (ΔE XB ) for iodoimide-pyridine complexes range from -44 to -99 kJ mol -1 , while for N-bromoimide-pyridine, they are between -31 and -77 kJ mol -1 . The ΔE XB of I⋯N XBs in 1:1 iodosaccharin:pyridine complexes are the largest of their kind, but they are substantially smaller than those in [bis(saccharinato)iodine(I)]pyridinium salts (-576 kJ mol -1 ), formed by N-iodosaccharin and pyridines. The NMR association constants and ΔE XB energies of 1:1 haloimide:pyridine complexes do not correlate as these complexes in solution are heavily influenced by secondary interactions, which DFT studies do not account for. Association constants follow the σ-hole strengths of N-haloimides, which agree with DFT and crystallography data. The haloimide:2-(N,N-dimethylamino)pyridine complex undergoes a halogenation reaction resulting in 5-iodo-2-dimethylaminopyridine., (© 2023 The Authors. Advanced Science published by Wiley-VCH GmbH.)

Homoleptic [L-I-L] + iodine(I) complexes (where L is a R 3 R 2 R 1 N tertiary amine) were synthesized via the [L-Ag-L] + → [L-I-L] + cation exchange reaction. In solution, the amines form [R 3 R 2 R 1 N-Ag-NR 1 R 2 R 3 ] + silver(I) complexes, which crystallize out from solution as the meso-[L-Ag-L] + complexes, as characterized by X-ray crystallography. The subsequent [L-I-L] + iodine(I) analogues were extremely reactive and could not be isolated in the solid state. Density functional theory (DFT) calculations were performed to study the Ag + -N and I + -N interaction energies in silver(I) and iodine(I) complexes, with the former ranging from -80 to -100 kJ mol -1 and latter from -260 to -279 kJ mol -1 . The X-ray crystal structures revealed Ag + ⋅⋅⋅C π and Ag + ⋅⋅⋅H-C short contacts between the silver(I) cation and flexible N-alkyl/N-aryl groups, which are the first of their kind in such precursor complexes., (© 2023 The Authors. Chemistry - A European Journal published by Wiley-VCH GmbH.)

Strong Lewis acids are essential tools for manifold chemical procedures, but their scalable deployment is limited by their costs and safety concerns. We report a scalable, convenient, and inexpensive synthesis of stable diiminium-based reagents with a Lewis acidic carbon centre. Coordination with pyridine donors stabilises these centres; the 2,2'-bipyridine adduct shows a chelation effect at carbon. Due to high fluoride, hydride, and oxide affinities, the diiminium pyridine adducts are promising soft and hard Lewis acids. They effectively produce acylpyridinium salts from carboxylates that can acylate amines to give amides and imides even from electronically intractable coupling partners., (© 2023 The Authors. Chemistry - A European Journal published by Wiley-VCH GmbH.)

Owing to the unknown correlation of a metal's ligand and its resulting preferred speciation in terms of oxidation state, geometry, and nuclearity, a rational design of multinuclear catalysts remains challenging. With the goal to accelerate the identification of suitable ligands that form trialkylphosphine-derived dihalogen-bridged Ni (I) dimers, we herein employed an assumption-based machine learning approach. The workflow offers guidance in ligand space for a desired speciation without (or only minimal) prior experimental data points. We experimentally verified the predictions and synthesized numerous novel Ni (I) dimers as well as explored their potential in catalysis. We demonstrate C-I selective arylations of polyhalogenated arenes bearing competing C-Br and C-Cl sites in under 5 min at room temperature using 0.2 mol % of the newly developed dimer, [Ni (I) (μ-Br)PAd 2 ( n -Bu)] 2 , which is so far unmet with alternative dinuclear or mononuclear Ni or Pd catalysts.

Sulfondiimines are marginalized entities among nitrogen-containing organosulfur compounds, despite offering promising properties for applications in various fields including medicinal and agrochemical. Herein, we present a metal-free and rapid synthetic procedure for the synthesis of N-monosubstituted sulfondiimines that overcomes current limitations in their synthetic accessibility. Particularly, S,S-dialkyl substrates, which are commonly difficult to convert by existing methods, react well with a combination of iodine, 1,8-diazabicyclo[5.4.0]undec-7-en (DBU), and iminoiodinanes (PhINR) in acetonitrile (MeCN) to furnish the corresponding sulfondiimines in yields up to 85 % (25 examples). Valuable "free" NH-N'H-sulfondiimines can then be accessed by N-deprotection under mild reaction conditions. Several experimental observations suggest a mechanistic pathway diverging from the common radical-based iodine/iminoiodinane mechanism. Based on the experimental results in combination with data obtained by 1 H NMR spectroscopy, ESI mass spectrometry, and crystallographic analysis we propose a direct amination from PhINNs and a reaction path via a cationic iodonitrene., (© 2023 The Authors. Angewandte Chemie International Edition published by Wiley-VCH GmbH.)

Building upon the first report of a 3-acetaminopyridine-based iodine(I) complex ( 1b ) and its unexpected reactivity toward t BuOMe, several new 3-substituted iodine(I) complexes ( 2b-5b ) have been synthesized. The iodine(I) complexes were synthesized from their analogous silver(I) complexes ( 2a-5a ) via a silver(I) to iodine(I) cation exchange reaction, incorporating functionally related substituents as 3-acetaminopyridine in 1b ; 3-acetylpyridine (3-Acpy; 2 ), 3-aminopyridine (3-NH 2 py; 3 ), and 3-dimethylaminopyridine (3-NMe 2 py; 4 ), as well as the strongly electron-withdrawing 3-cyanopyridine (3-CNpy; 5 ), to probe the possible limitations of iodine(I) complex formation. The individual properties of these rare examples of iodine(I) complexes incorporating 3-substituted pyridines are also compared to each other and contrasted to their 4-substituted counterparts which are more prevalent in the literature. While the reactivity of 1b toward etheric solvents could not be reproduced in any of the functionally related analogues synthesized herein, the reactivity of 1b was further expanded to a second etheric solvent. Reaction of bis (3-acetaminopyridine)iodine(I) ( 1b ) and i Pr 2 O gave [3-acetamido-1-(3-iodo-2-methylpentan-2-yl)pyridin-1-ium]PF 6 ( 1d ), which demonstrated potentially useful C-C and C-I bond formation under ambient conditions., Competing Interests: The authors declare no competing financial interest., (© 2023 The Authors. Published by American Chemical Society.)

Two different organometallic gold(I) compounds containing naphthalene and phenanthrene as fluorophores and 2-pyridyldiphenylphosphane as the ancillary ligand were synthesized (compounds 1 with naphthalene and 2 with phenanthrene). They were reacted with three different copper(I) salts with different counterions (PF 6 - , OTf - , and BF 4 - ; OTf = triflate) to obtain six Au(I)/Cu(I) heterometallic clusters (compounds 1a - c for naphthalene derivatives and 2a - c for phenanthrene derivatives). The heterometallic compounds present red pure room-temperature phosphorescence in both solution, the solid state, and air-equilibrated samples, as a difference with the dual emission recorded for the gold(I) precursors 1 and 2 . The presence of Au(I)-Cu(I) metallophilic contacts has been identified using single-crystal X-ray diffraction structure resolution of two of the compounds, which play a direct role in the resulting red-shifted emission with respect to the gold(I) homometallic precursors. Polystyrene (PS) and poly(methyl methacrylate) (PMMA) polymeric matrices were doped with our luminescent compounds, and the resulting changes in their emissive properties were analyzed and compared with those previously recorded in the solution and the solid state. All complexes were tested to analyze their ability to produce 1 O 2 and present very good values of Φ Δ up to 50%.

Intestinal bile acids play an essential role in the Clostridioides difficile lifecycle having been shown in vitro to modulate various aspects of pathogenesis, including spore germination, vegetative growth, and more recently the action of the primary virulence determinant, TcdB. Here, we investigated whether physiological levels of the total pool of intestinal bile acids in mice and humans protect against TcdB action. Small molecules extracted from the lumenal contents of the small intestine, cecum, colon, and feces were found to inhibit TcdB in accordance with the differential amounts of total bile acids in each compartment. Extracts from antibiotic-treated and germ-free mice, despite harboring dramatically altered bile acid profiles, unexpectedly also prevented TcdB-induced cell rounding to similar extents. We show that protection, however, is surmountable and can be overcome at higher doses of TcdB-typical to those seen during severe C. difficile infection-suggesting that the protective properties of intestinal bile acids are operant primarily under low to moderate toxin levels. Taken together, these findings demonstrate a role for intestinal bile acids in attenuating virulence, provide insights into asymptomatic carriage of toxigenic C. difficile , and inform strategies to manipulate bile acid levels for therapeutic benefit.

Three chiral carbonyl hypoiodites, R-C(O)OI, have been prepared from N-protected ( S )-valine to give the ligand-stabilised ( S )-valinoyl hypoiodite complexes with 4-dimethylaminopyridine, 4-pyrrolidinopyridine, and 4-morpholinopyridine as the stabilising ligands. The identity of the complexes was established by NMR ( 1 H, 13 C, 1 H- 15 N HMBC) and single crystal X-ray diffraction analysis.

Objectives: To examine changes in the positive infectious syphilis test rate among women and heterosexual men in major Australian cities, and rate differences by social, biomedical, and behavioural determinants of health., Design, Setting: Analysis of data extracted from de-identified patient records from 34 sexual health clinics participating in the Australian Collaboration for Coordinated Enhanced Sentinel Surveillance of Sexually Transmissible Infections and Blood Borne Viruses (ACCESS)., Participants: First tests during calendar year for women and heterosexual men aged 15 years or more in major cities who attended ACCESS sexual health clinics during 2011-2019., Main Outcome Measures: Positive infectious syphilis test rate; change in annual positive test rate., Results: 180 of 52 221 tested women (0.34%) and 239 of 36 341 heterosexual men (0.66%) were diagnosed with infectious syphilis. The positive test rate for women was 1.8 (95% confidence interval [CI], 0.9-3.2) per 1000 tests in 2011, 3.0 (95% CI, 2.0-4.2) per 1000 tests in 2019 (change per year: rate ratio [RR], 1.12; 95% CI, 1.01-1.25); for heterosexual men it was 6.1 (95% CI, 3.8-9.2) per 1000 tests in 2011 and 7.6 (95% CI, 5.6-10) per 1000 tests in 2019 (RR, 1.10; 95% CI, 1.03-1.17). In multivariable analyses, the positive test rate was higher for women (adjusted RR [aRR], 1.85; 95% CI, 1.34-2.55) and heterosexual men (aRR, 2.39; 95% CI, 1.53-3.74) in areas of greatest socio-economic disadvantage than for those in areas of least socio-economic disadvantage. It was also higher for Indigenous women (aRR, 2.39; 95% CI, 1.22-4.70) and for women who reported recent injection drug use (aRR, 4.87; 95% CI, 2.18-10.9) than for other women; it was lower for bisexual than heterosexual women (aRR, 0.48; 95% CI, 0.29-0.81) and for women who reported recent sex work (aRR, 0.35; 95% CI, 0.29-0.44). The positive test rate was higher for heterosexual men aged 40-49 years (aRR, 2.11; 95% CI, 1.42-3.12) or more than 50 years (aRR, 2.36; 95% CI, 1.53-3.65) than for those aged 15-29 years., Conclusion: The positive test rate among both urban women and heterosexual men tested was higher in 2019 than in 2011. People who attend reproductive health or alcohol and drug services should be routinely screened for syphilis., (© 2023 The Authors. Medical Journal of Australia published by John Wiley & Sons Australia, Ltd on behalf of AMPCo Pty Ltd.)

Solid-state NMR has been applied to a series of Barluenga-type iodine(I) [L-I-L]PF 6 (L=pyridine, 4-ethylpyridine, 4-dimethylaminopyridine, isoquinoline) complexes as their hexafluorophosphate salts, as well as their respective non-liquid ligands (L), their precursor silver(I) complexes, and the respective N-methylated pyridinium and quinolinium hexafluorophoshate salts. These results are compared and contrasted to the corresponding solution studies and single-crystal X-ray structures. As the first study of its kind on the solid-state NMR behavior of halogen(I) complexes, practical considerations are also discussed to encourage wider utilization of this technique in the future., (© 2023 Wiley-VCH GmbH.)

Six new crotofolane diterpenoids ( 1 - 6 ) and 13 known compounds ( 7 - 19 ) were isolated from the MeOH-CH 2 Cl 2 (1:1, v/v) extracts of the leaves and stem bark of Croton kilwae . The structures of the new compounds were elucidated by extensive analysis of spectroscopic and mass spectrometric data. The structure of crotokilwaepoxide A ( 1 ) was confirmed by single-crystal X-ray diffraction, allowing for the determination of its absolute configuration. The crude extracts and the isolated compounds were investigated for antiviral activity against respiratory syncytial virus (RSV) and human rhinovirus type-2 (HRV-2) in HEp-2 and HeLa cells, respectively, for antibacterial activity against the Gram-positive Bacillus subtilis and the Gram-negative Escherichia coli , and for antimalarial activity against the Plasmodium falciparum Dd2 strain. ent -3β,19-Dihydroxykaur-16-ene ( 7 ) and ayanin ( 16 ) displayed anti-RSV activities with IC 50 values of 10.2 and 6.1 μM, respectively, while exhibiting only modest cytotoxic effects on HEp-2 cells that resulted in selectivity indices of 4.9 and 16.4. Compounds 2 and 5 exhibited modest anti-HRV-2 activity (IC 50 of 44.6 μM for both compounds), while compound 16 inhibited HRV-2 with an IC 50 value of 1.8 μM. Compounds 1 - 3 showed promising antiplasmodial activities (80-100% inhibition) at a 50 μM concentration.

Two series of Pt(II)-cyclometallated compounds containing N^C^N tridentate and alkynyl-chromophore ligands have been synthesized and structurally characterized. The N^C^N ligands differ on the presence of R 1 = H or F in the central aromatic ring, while six different chromophores have been introduced to the alkynyl moiety. Single-crystal X-ray structures for some of the compounds reveal the presence of weak intermolecular contacts responsible for the formation of some dimers or aggregates. The photophysical characterization shows the presence of two emission bands in solution assigned to the 3 π-π* transition from the N^C^N ligands mixed with 3 MLCT/ 3 ILCT transitions (higher energy band) in deaerated samples. The formation of excimers has also been identified as a broad band at longer wavelengths [near-infrared (NIR) emission] that becomes the main emission band for compounds containing phenanthrene as the chromophore. NIR emission behavior has also been explored using acetonitrile/water mixtures, and the presence of aggregates that emit at ca. 650 nm has also been detected.

Cholesterol reacts under Appel conditions (CBr 4 /PPh 3 ) to give 3,5-cholestadiene (elimination) and 3β-bromocholest-5-ene (substitution with retention of configuration). Thus, the bromination of cholesterol deviates from the stereochemistry of the standard Appel mechanism due to participation of the Δ 5 π-electrons. In contrast, the subsequent azidolysis (NaN 3 /DMF) of 3β-bromocholest-5-ene proceeds predominantly by Walden inversion (S N 2) affording 3α-azidocholest-5-ene. The structures of all relevant products were revealed by X-ray single crystal structure analyses, and the NMR data are in agreement to the reported ones. In light of these findings, we herein correct the previous stereochemical assignments reported by one of us in the Beilstein J. Org. Chem. 2015 , 11 , 1922-1932 and the Monatsh. Chem. 2018 , 149 , 505-517., (Copyright © 2023, Schumacher et al.)

Two series of dinuclear gold(I) complexes that contain two Au-chromophore units (chromophore = dibenzofurane or dimethylfluorene) connected through a diphosphane bridge that differs in the flexibility and length (diphosphane = dppb for 1,4-bis(diphenylphosphino)butane, DPEphos for bis[(2-diphenylphosphino)phenyl]ether, xanthphos for 4,5-bis(diphenylphosphino)-9,9-dimethylxanthene, and BiPheP for 2,2'-bis(diphenylphosphino)-1,1'-biphenyl) have been synthesized and structurally characterized. Their photophysical properties have been carefully investigated, paying attention to the role of the presence, or absence, of aurophilic contacts and their nature (intra- or intermolecular character). This analysis was permitted due to the X-ray crystallographic determination of all of the structures of the compounds discussed herein. The quantum yields of the triplet population, ϕ T , have been calculated by nanosecond-laser flash photolysis measurements, and we could determine the main role of the character of the aurophilic contacts in the resulting ϕ T , being especially favored in the presence of intermolecular contacts. Time-dependent density functional theory (TD-DFT) calculations support the absorption and emission assignments and the shorter distance between S 1 and the closest triplet excited state energy in the case of the compounds with a higher triplet-state population.

Giant octahedral M 32 coordination cages were prepared via self-assembly of sulfonylcalix[4]arene-supported tetranuclear M(II) clusters (M = Co, Ni) with hybrid linker based on tris(dipyrrinato)cobalt(III) complexes appended with peripherical carboxylic groups. Due to intrinsic and extrinsic porosity, the obtained solid-state supramolecular architectures demonstrated good performance as adsorbents for the separation of industrially important gases mixtures.

The first tris (O-I-N) carbonyl hypoiodites have been synthesised based on trimesic acid and pyridine or 4-methylpyridine, with their structures definitively confirmed by single crystal X-ray diffraction (SCXRD). The more soluble carbonyl hypoiodites based on pivalic acid have also been studied via NMR, SCXRD, and computational analyses, enabling the study of the direct silver(I) precursor and intermediates of the resulting carbonyl hypoiodites generated using a range of substituted pyridines.

The leaf extract of Suregada zanzibariensis gave two new modified ent -abietane diterpenoids, zanzibariolides A ( 1 ) and B ( 2 ), and two known triterpenoids, simiarenol ( 3 ) and β-amyrin ( 4 ). The structures of the isolated compounds were elucidated based on NMR and MS data analysis. Single-crystal X-ray diffraction was used to establish the absolute configurations of compounds 1 and 2 . The crude leaf extract inhibited the infectivity of herpes simplex virus 2 (HSV-2, IC 50 11.5 μg/mL) and showed toxicity on African green monkey kidney (GMK AH1) cells at CC 50 52 μg/mL. The isolated compounds 1 - 3 showed no anti-HSV-2 activity and exhibited insignificant toxicity against GMK AH1 cells at ≥100 μM.

Objective: The purpose of this study was to assess the protective influence of the Serola Sacroiliac Belt on pain and functional impairment in individuals with low back pain (LBP) during 5 days of strenuous manual labor., Methods: Thirty-three participants (mean ± standard deviation: age, 43.2 ± 11.4 years; height, 1.74 ± 0.11 m; body mass index, 88.3 ± 16.7 kg) with LBP were randomized to either condition A (wearing the Serola Sacroiliac Belt during a 10-minute daily repeated strenuous lifting task) during week 1 or condition B (not wearing a Serola Sacroiliac Belt during the same lifting task) in week 2 or vice versa. All 33 participants completed 1 week under condition A and 1 week under condition B for comparison. At the beginning and end of each week, the following dependent variables were measured: lumbar spine pain on a 0 to 10 Numeric Rating Scale (NRS), spine and thigh discomfort on a Nordic Musculoskeletal Questionnaire, and completion of a toe-touch surface electromyography flexion relaxation phenomenon test., Results: During the week that participants used the Serola Sacroiliac Belt, spine pain increased 0.2 compared with 0.9 on the NRS for those who did not use the belt. No statistically significant difference was observed for Nordic Musculoskeletal Questionnaire data or the flexion relaxation phenomenon test in this study., Conclusion: The findings of this preliminary study suggest participants using the Serola Sacroiliac Belt while performing a daily repeated lifting task had less progression of their LBP. However, this protective value did not meet the recommended NRS for minimally clinically important difference, and there was no effect on functional impairment., (© 2022 by National University of Health Sciences.)

The base-promoted direct amidation of unactivated esters is among the most useful reactions for amide bond formation in contemporary organic chemistry. The intensive research in this area has led to the development of a number of new methods to achive this transformation. However, to date, the existing literature is more methodological and in many instances lacks practical directions. Therefore, the full potential of this transformation is yet to be revealed by broadening the substrate scope. In a search for new practical applications of the amidation reaction, herein we present a comprehensive study of a number of base-promoted direct amidations that encompass a wide range of amines and esters. Furthermore, we applied our findings in the synthesis of phosphoramidates and several industrially relevant products., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)

Herein we report on the synthesis of six new phosphane-gold(I)-4-ethynylaniline complexes (neutral and cationic), with a tris-naphthalene substituted tertiary phosphane bearing a secondary amine as a linker and containing different halogen groups (Cl and Br) in the naphthyl group. We have demonstrated in this work how the careful control of the intermolecular aggregation process can modulate the competition between phosphorescence emission and energy transfer from the triplet state of the gold(I) complexes to produce singlet oxygen.

The interaction of a [bis(pyridine)iodine(I)] + cation with a [bis(pyridine)silver(I)] + cation, in which an iodonium ion acts as a nucleophile by transferring electron density to the silver(I) cation, is reinvestigated herein. No measurable interaction is observed between the cationic species in solution by NMR; DFT reveals that if there is an attractive interaction between these complexes in solution, it is dominantly the π-π interaction of pyridines.

A detailed investigation of ligand exchange between iodine(I) ions in [N⋯I⋯N] + halogen-bonded complexes is presented. Ligand exchange reactions were conducted to successfully confirm whether iodine(I) complex formation, via the classical [N⋯Ag⋯N] + to [N⋯I⋯N] + cation exchange reaction from their analogous Ag + complexes, could be determined solely by using 1 H NMR spectroscopy. In instances where the formation of the iodine(I) complex was unclear or in low yield by the traditional cation exchange reaction, a ligand exchange reaction was used to form the desired iodine(I) complexes in a quantitative manner. Mixing two homoleptic [N⋯I⋯N] + iodine(I) complexes in 1 : 1 ratio was found to undergo a statistical ligand exchange, with 1 H NMR studies showing that the preferred formation of the relative heteroleptic [N 1 ⋯I⋯N 2 ] + complexes increases with greater differences in the Lewis basicities of two XB acceptors of the complexes involved.

The silver(i) and iodine(i) complexes of the 2-substituted pyridines 2-(diphenylmethyl)pyridine (1) and 2-(1,1-diphenylethyl)pyridine (2), along with their potential protonated side products, were synthesised to investigate the steric limitations of iodine(i) complex formation. The complexes were characterised by 1 H and 1 H- 15 N HMBC NMR, X-ray crystallography, and DFT calculations. The solid-state structures for the silver(i) and iodine(i) complexes were extensively compared to the literature and analysed by DFT to examine the influence of the sterically bulky pyridines and their anions., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)

Background: A syphilis outbreak among Australian Aboriginal and Torres Strait Islander people (respectfully referred to as Aboriginal) has resulted in almost 4000 notifications by 2020, with several congenital syphilis cases and infant deaths. Outbreak control efforts became coordinated under a National enhanced test and treat response in 2017. We evaluated the impact of these efforts and of expansion of testing interventions on syphilis prevalence., Methods: We developed an individual-based mathematical model of infectious syphilis transmission among young heterosexual Aboriginal people aged 15-34 years living in and moving between regional and remote areas, and we assessed the impact of existing and hypothetical outbreak control responses on syphilis prevalence., Results: The increased testing coverage achieved through the response (from 18% to 39% over 2011-2020) could stabilize the epidemic from 2021. To return to pre-outbreak prevalence (<0.24%) by 2025, testing coverage must reach 60%. The addition of annual community-wide screening, where 30% of youth in communities are tested over 6 weeks, would reduce prevalence to the pre-outbreak level within 4 years. If testing coverage had been scaled-up to 60% at the start of outbreak in mid-2011, the outbreak would have been mitigated., Conclusions: Our results suggest that to control the syphilis outbreak, the response needs to be delivered to enable the maximum coverage of testing to be reached in the shortest time to reduce the prevalence to pre-outbreak levels. Reduction could be hastened with community-wide screening at similar time periods across all communities together with increases in annual testing coverage., (© The Author(s) 2022. Published by Oxford University Press on behalf of Infectious Diseases Society of America.)

We describe herein the self-assembly synthesis of an octanuclear Co II [2]catenane {[Co 4 (H 2 L) 6 ] 2 16+ } formed by the mechanical interlocking of two {[Co 4 (H 2 L) 6 ] 8+ } rectangles of unprecedented topology. Subtle manipulation of the synthetic conditions allows the isolation of a mixed-valence [Co 2 III /Co 2 II ] 10+ non-catenated rectangle. The Co II centers in the [2]catenane exhibit slow relaxation of their magnetic moment, i. e. single-molecule magnet properties, dominated by quantum tunneling and Raman relaxation processes. This work shows that metallo-supramolecular chemistry can precisely control the organization of single-molecule magnets in topologically complex arrangements., (© 2021 Wiley-VCH GmbH.)

The aggregation process of a series of mono- and dinuclear gold(I) complexes containing a 4-ethynylaniline ligand and a phosphane at the second coordination position (PR 3 -Au-C≡CC 6 H 4 -NH 2 , complexes 1 - 5 , and (diphos)(Au-C≡CC 6 H 4 -NH 2 ) 2 , complexes 6 - 8 ), whose biological activity was previously studied by us, has been carefully analyzed through absorption, emission, and NMR spectroscopy, together with dynamic light scattering and small-angle X-ray scattering. These experiments allow us to retrieve information about how the compounds enter the cells. It was observed that all compounds present aggregation in fresh solutions, before biological treatment, and thus they must be entering the cells as aggregates. Inductively coupled plasma atomic emission spectrometry measurements showed that mononuclear complexes are mainly found in the cytosolic fraction; the dinuclear complexes are mainly found in a subsequent fraction composed of nuclei and cytoskeleton. Additionally, dinuclear complex 8 affects the actin aggregation to a larger extent, suggesting a cooperative effect of dinuclear compounds.

Although machine learning bears enormous potential to accelerate developments in homogeneous catalysis, the frequent need for extensive experimental data can be a bottleneck for implementation. Here, we report an unsupervised machine learning workflow that uses only five experimental data points. It makes use of generalized parameter databases that are complemented with problem-specific in silico data acquisition and clustering. We showcase the power of this strategy for the challenging problem of speciation of palladium (Pd) catalysts, for which a mechanistic rationale is currently lacking. From a total space of 348 ligands, the algorithm predicted, and we experimentally verified, a number of phosphine ligands (including previously never synthesized ones) that give dinuclear Pd (I) complexes over the more common Pd (0) and Pd (II) species.

Four bis (O-I-N) compounds have been synthesised from various dihypoiodites and 4-ethylpyridine. The compounds were characterised in both the solution and solid states by NMR spectroscopy ( 1 H, 15 N), X-ray diffraction, and computational calculations.