Synthesis, Characterization, and Photochemistry of a GaL Coordination Cage with Dithienylethene-Catecholate Ligands.

Two new photoswitchable dithienylethene (DTE)-catechol ligands, specifically designed for group 13 metal coordination, were synthesized via Suzuki coupling reactions from a dichloro-DTE building block, each with varying longitudinal extensions. The shorter DTE-catechol ligand did not efficiently assemble with Ga metal ions; however, elongation with a phenylene-amide spacer group enabled the successful formation of a novel triply DTE-functionalized coordination [GaL] cage. This cage represents a unique example of integrating DTE photoswitches with main group metals in a supramolecular coordination framework.

Reversible Redox Ligand-Centered Reactivity in 2,6-Bisiminopyridine Aluminum Systems.

We report the synthesis of cationic 2,6-bisiminopyridine organoaluminum complexes, [(BIP)AlR], as stable BAr or PF salts, and their reversible single-electron reduction into well-defined paramagnetic species, [(BIP·)AlR]. Four redox couples, [(BIP)AlR], have been fully characterized through structural, spectroscopic, electrochemical and computational techniques.

The Iron and Calcium Availability and the Satiating Effect of Different Biscuits.

Biscuits are bakery products made with wheat flour. Wheat is a good source of minerals and dietary fibre, although the presence of phytate or other components could modify mineral availability. In addition, cereal-based products are usually characterised by high fibre content that can influence satiety.

Dehydropolymerization of Amine-Boranes using Bis(imino)pyridine Rhodium Pre-Catalysis: σ-Amine-Borane Complexes, Nanoparticles, and Low Residual-Metal BN-Polymers that can be Chemically Repurposed.

The sigma amine-borane complexes [Rh(L1)(η :η -H B⋅NRH )][OTf] (L1=2,6-bis-[1-(2,6-diisopropylphenylimino)ethyl]pyridine, R=Me, Et, Pr) are described, alongside [Rh(L1)(NMeH )][OTf]. Using R=Me as a pre-catalyst (1 mol %) the dehydropolymerization of H B ⋅ NMeH gives [H BNMeH] selectively. Added NMeH , or the direct use of [Rh(L1)(NMeH )][OTf], is required for initiation of catalysis, which is suggested to operate through the formation of a neutral hydride complex, Rh(L1)H.

Revealing unbound β-diketiminate anions: structural dynamics from caesium complexes.

This study reports the first structural elucidation of β-diketiminate anions (BDI), known for strong coordination, in their unbound form within caesium complexes. β-Diketiminate caesium salts (BDICs) were synthesised, and upon the addition of Lewis donor ligands, free BDI anions and donor-solvated Cs cations were observed. Notably, the liberated BDI anions exhibited an unprecedented dynamic - exchange in solution.

Photofunctional Scope of Fluorescent Dithienylethene Conjugates with Aza-Heteroaromatic Cations.

A series of dithienylethene (DTE) photoswitches with aza-heteroaromatic cationic moieties is synthesized. The switches are characterized regarding their photochemical and photophysical properties in acetonitrile and in water. The efficiency of the switching and the photostationary state composition depend on the degree of π-conjugation of the heteroaromatic systems.

Inverse Isotope Effects in Single-Crystal to Single-Crystal Reactivity and the Isolation of a Rhodium Cyclooctane σ-Alkane Complex.

The sequential solid/gas single-crystal to single-crystal reaction of [Rh(CyP(CH)PCy)(COD)][BAr ] (COD = cyclooctadiene) with H or D was followed in situ by solid-state P{H} NMR spectroscopy (SSNMR) and ex situ by solution quenching and GC-MS. This was quantified using a two-step Johnson-Mehl-Avrami-Kologoromov (JMAK) model that revealed an inverse isotope effect for the second addition of H, that forms a σ-alkane complex [Rh(CyP(CH)PCy)(COA)][BAr ]. Using D, a temporal window is determined in which a structural solution for this σ-alkane complex is possible, which reveals an η,η-binding mode to the Rh(I) center, as supported by periodic density functional theory (DFT) calculations.

Organotelluroxane molecular clusters assembled Te⋯X (X = Cl, Br) chalcogen bonding anion template interactions.

The synthesis and characterisation of two novel molecular organotelluroxane clusters, comprising of an inorganic TeOX (X = Cl, Br) core structure are described. The integration of highly electron withdrawing 3,5-bis-trifluoromethylphenyl groups to the constituent Te(IV) centres is determined to be crucial in the chalcogen bonding (ChB) halide template directed assembly. Characterised by multi-nuclear H, Te, F NMR, UV-Vis, IR spectroscopies and X-ray crystal structure analysis, the discrete molecular clusters exhibit excellent organic solvent solubility and remarkable chemical stability.

-aryl substituted DPEphos ligands: rhodium complexes featuring C-H anagostic interactions and B-H agostic bonds.

The synthesis of new Schrock-Osborn Rh(i) pre-catalysts with -substituted DPEphos ligands, [Rh(DPEphos-R)(NBD)][BAr ] [R = Me, OMe, Pr; Ar = 3,5-(CF)CH], is described. Along with the previously reported R = H variant, variable temperature H NMR spectroscopic and single-crystal X-ray diffraction studies show that these all have axial (C-H)⋯Rh anagostic interactions relative to the d pseudo square planar metal centres, that also result in corresponding downfield chemical shifts. Analysis by NBO, QTAIM and NCI methods shows these to be only very weak C-H⋯Rh bonding interactions, the magnitudes of which do not correlate with the observed chemical shifts.

Chalcogen Bonding Ion-Pair Cryptand Host Discrimination of Potassium Halide Salts.

A series of chalcogen, halogen and hydrogen bonding heteroditopic macrobicyclic cryptands are reported and their potassium halide ion-pair recognition properties investigated. Saliently, the co-bound potassium cation was determined to be crucial in switching on the bromide and iodide recognition properties of the respective cryptand receptor. Importantly, the nature of the sigma-hole mediated interaction employed in the anion recognition component is demonstrated to significantly augment the ion-pair binding behaviour, markedly so for the halogen bonding analogue.

A Series of Crystallographically Characterized Linear and Branched σ-Alkane Complexes of Rhodium: From Propane to 3-Methylpentane.

Using solid-state molecular organometallic (SMOM) techniques, in particular solid/gas single-crystal to single-crystal reactivity, a series of σ-alkane complexes of the general formula [Rh(CyPCHCHPCy)(η:η-alkane)][BAr] have been prepared (alkane = propane, 2-methylbutane, hexane, 3-methylpentane; Ar = 3,5-(CF)CH). These new complexes have been characterized using single crystal X-ray diffraction, solid-state NMR spectroscopy and DFT computational techniques and present a variety of Rh(I)···H-C binding motifs at the metal coordination site: 1,2-η:η (2-methylbutane), 1,3-η:η (propane), 2,4-η:η (hexane), and 1,4-η:η (3-methylpentane). For the linear alkanes propane and hexane, some additional Rh(I)···H-C interactions with the geminal C-H bonds are also evident.

η-Alkene Complexes of [Rh(PONOP-Pr)(L)] Cations (L = COD, NBD, Ethene). Intramolecular Alkene-Assisted Hydrogenation and Dihydrogen Complex [Rh(PONOP-Pr)(η-H)].

Rhodium-alkene complexes of the pincer ligand κ-CHN-2,6-(OPPr) (PONOP-Pr) have been prepared and structurally characterized: [Rh(PONOP-Pr)(η-alkene)][BAr] [alkene = cyclooctadiene (COD), norbornadiene (NBD), ethene; Ar = 3,5-(CF)CH]. Only one of these, alkene = COD, undergoes a reaction with H (1 bar), to form [Rh(PONOP-Pr)(η-COE)][BAr] (COE = cyclooctene), while the others show no significant reactivity. This COE complex does not undergo further hydrogenation.

Acute mesenteric thrombosis in two patients with COVID-19. Two cases report and literature review.

Introduction: The coronavirus disease 2019 (COVID-19) affects mainly the respiratory system, other organs may be involved, usually due to coagulation disturbances that lead to a high rate of thrombotic complications.

Case Presentation: The first patient is 45 years-old who has been exposed to SARS CoV-2. Upon admission due to acute abdomen evidence surgery is performed in which an intestinal resection with an adequate post-surgical evolution takes place so the patient is discharged after 4 days with a prescription for oral anticoagulants.

Transillumination of Calot's Triangle on Laparoscopic Cholecystectomy: A Feasible Approach to Achieve a Critical View of Safety.

Background Laparoscopic cholecystectomy is currently one of the most commonly performed procedures globally. Morbidity of laparoscopic cholecystectomy is low; however, bile duct injury is still a feared complication. Despite worldwide efforts, the global incidence of bile duct injury remains higher for laparoscopic cholecystectomy compared with open cholecystectomy.

Solid-State Molecular Organometallic Catalysis in Gas/Solid Flow (Flow-SMOM) as Demonstrated by Efficient Room Temperature and Pressure 1-Butene Isomerization.

The use of solid-state molecular organometallic chemistry (SMOM-chem) to promote the efficient double bond isomerization of 1-butene to 2-butenes under flow-reactor conditions is reported. Single crystalline catalysts based upon the σ-alkane complexes [Rh(RPCHCHPR)(ηη-NBA)][BAr ] (R = Cy, Bu; NBA = norbornane; Ar = 3,5-(CF)CH) are prepared by hydrogenation of a norbornadiene precursor. For the Bu-substituted system this results in the loss of long-range order, which can be re-established by addition of 1-butene to the material to form a mixture of [Rh(BuPCHCHPBu)(-2-butene)][BAr ] and [Rh(BuPCHCHPBu)(1-butene)][BAr ], in an order/disorder/order phase change.

A Structurally Characterized Cobalt(I) σ-Alkane Complex.

A cobalt σ-alkane complex, [Co(Cy P(CH ) PCy )(norbornane)][BAr ], was synthesized by a single-crystal to single-crystal solid/gas hydrogenation from a norbornadiene precursor, and its structure was determined by X-ray crystallography. Magnetic data show this complex to be a triplet. Periodic DFT and electronic structure analyses revealed weak C-H→Co σ-interactions, augmented by dispersive stabilization between the alkane ligand and the anion microenvironment.

Reversible Encapsulation of Xenon and CH Cl in a Solid-State Molecular Organometallic Framework (Guest@SMOM).

Reversible encapsulation of CH Cl or Xe in a non-porous solid-state molecular organometallic framework of [Rh(Cy PCH PCy )(NBD)][BAr ] occurs in single-crystal to single-crystal transformations. These processes are probed by solid-state NMR spectroscopy, including Xe SSNMR. Non-covalent interactions with the -CF groups, and hydrophobic channels formed, of [BAr ] anions are shown to be important, and thus have similarity to the transport of substrates and products to and from the active site in metalloenzymes.

The role of neutral Rh(PONOP)H, free NMeH, boronium and ammonium salts in the dehydrocoupling of dimethylamine-borane using the cationic pincer [Rh(PONOP)(η-H)] catalyst.

The σ-amine-borane pincer complex [Rh(PONOP)(η1-H3B·NMe3)][BArF4] [2, PONOP = κ3-NC5H3-2,6-(OPtBu2)2] is prepared by addition of H3B·NMe3 to the dihydrogen precursor [Rh(PONOP)(η2-H2)][BArF4], 1. In a similar way the related H3B·NMe2H complex [Rh(PONOP)(η1-H3B·NMe2H)][BArF4], 3, can be made in situ, but this undergoes dehydrocoupling to reform 1 and give the aminoborane dimer [H2BNMe2]2. NMR studies on this system reveal an intermediate neutral hydride forms, Rh(PONOP)H, 4, that has been prepared independently.

Selective mono- and dimetallation of a group 3 sandwich complex.

The scandium Cp/COT hybrid sandwich compound [(η-CH)Sc(η-CH)] is resistant to metallation via conventional alkyllithium and lithium amide bases. In this work, clean, selective, stoichiometric and high-yielding mono- and dimetallation is accomplished using tandem trans-metal-trapping (TMT) involving LiTMP and iBuAlTMP with deprotonation occurring selectively at the Cp and Cp/COT rings respectively, providing the first examples of selective metallation of a sandwich complex featuring a group 3 element.

A Potent Halogen-Bonding Donor Motif for Anion Recognition and Anion Template Mechanical Bond Synthesis.

The covalent attachment of electron deficient perfluoroaryl substituents to a bis-iodotriazole pyridinium group produces a remarkably potent halogen bonding donor motif for anion recognition in aqueous media. Such a motif also establishes halogen bonding anion templation as a highly efficient method for constructing a mechanically interlocked molecule in unprecedented near quantitative yield. The resulting bis-perfluoroaryl substituted iodotriazole pyridinium axle containing halogen bonding [2]rotaxane host exhibits exceptionally strong halide binding affinities in competitive 50 % water containing aqueous media, by a factor of at least three orders of magnitude greater in comparison to a hydrogen bonding rotaxane host analogue.

Evaluation of the serum procalcitonin level as an indicator of severity and mortality in abdominal sepsis due to secondary peritonitis.

Background: Procalcitonin is a biomarker of sepsis, whose concentrations increase when some endotoxin enters the bloodstream. It is used, among other things, to discriminate the etiology of infections, increase or decrease the antibiotic spectrum, and predict mortality.

Objective: To determine the utility of the serum level of procalcitonin as a predictor of severity and mortality.

A d Ag(i) amine-borane σ-complex and comparison with a d Rh(i) analogue: structures on the η to η:η continuum.

H3B·NMe3 σ-complexes of d8 [(L1)Rh][BArF4] and d10 [(L1)Ag][BArF4] (where L1 = 2,6-bis-[1-(2,6-diisopropylphenylimino)ethyl]pyridine) have been prepared and structurally characterised. Analysis of the molecular and electronic structures reveal important but subtle differences in the nature of the bonding in these σ-complexes, which differ only by the identity of the metal centre and the d-electron count. With Rh the amine-borane binds in an η2:η2 fashion, whereas at Ag the unsymmetrical {AgH3B·NMe3} unit suggests a structure lying between the η2:η2 and η1 extremes.

Solvent-free anhydrous Li, Na and K salts of [B(3,5-(CF)CH)], [BAr]. Improved synthesis and solid-state structures.

A modified, convenient, preparation of solvent-free, anhydrous, Li+, Na+ and K+ salts of the ubiquitous [BArF4]- anion is reported, that involves a simple additional recrystallisation step. Anhydrous Na[BArF4], K[BArF4], and [Li(H2O)][BArF4], were characterised by single-crystal X-ray diffraction.