Bis[2,6-bis-(1H-benzimidazol-2-yl)pyridine]ruthenium(II) bis(hexa-fluorido-phosphate) diethyl ether tris-olvate.

The title compound, [Ru(C19H13N5)2](PF6)2·3C4H10O, was obtained from the reaction of Ru(bimpy)Cl3 [bimpy is 2,6-bis-(1H-benzimidazol-2-yl)pyridine] and bimpy in refluxing ethanol followed by recrystallization from diethyl ether/aceto-nitrile. At 125 K the complex has ortho-rhom-bic (Pca21) symmetry. It is remarkable that the structure is almost centrosymmetric. However, refinement in space group Pbcn leads to disorder and definitely worse results. It is of inter-est with respect to potential catalytic reduction of CO2. The structure displays N-H⋯O, N-H⋯F hydrogen bonding and significant π-π stacking and C-H⋯π stacking inter-actions.

Synthesis, Characterization, and Single-Crystal X-ray Structures of Refractory Metal Compounds as Precursors for the Single-Source Chemical Vapor Deposition of Metal Nitrides.

The chemical vapor deposition of refractory metal nitrides requires volatile precursors and has previously been achieved by using metal complexes containing a variety of imide ligands. Recently, the 1,4-di-tert-butyl-1,3-diazabutadiene (DAD) adduct of bis(tert-butylimide)dichloridemolybdenum(VI) was shown to be an excellent precursor for the single-source CVD of Mo2N thin films. Leveraging the success of this work, we prepared chromium and tungsten compounds with the same framework. Additionally, the framework has been modified slightly to allow the isolation of mono(tert-butylimide)trichloride complexes of vanadium, niobium, tantalum, and molybdenum(V) to extend the search for new vapor-phase precursors. These compounds were all fully characterized using the standard methods of multinuclear magnetic resonance spectroscopy, combustion analysis, and single-crystal X-ray diffraction. Their thermal properties were determined by using thermogravimetric analysis and differential scanning colorimetry to assess their utility as vapor-phase precursors. Finally, preliminary deposition studies were carried out to investigate their potential as single-source CVD precursors.

Highly Selective Nickel-Catalyzed Isomerization-Hydroboration of Alkenes Affords Terminal Functionalization at Remote C-H Position.

We report herein the synthesis and characterization of nickel complexes supported by tridentate and bidentate phosphino(silyl) ancillary ligands, along with the successful application of these complexes as precatalysts for the hydroboration of terminal and internal alkenes using pinacolborane (HBPin). These reactions proceeded with low nickel loadings of 2.5-5 mol % in the absence of co-solvent, and in some cases at room temperature. Isomerization to afford exclusively the terminal hydroboration product was obtained across a range of internal alkenes, including tri- and tetra-substituted examples. This reactivity is unprecedented for nickel and offers a powerful means of achieving functionalization at a C-H position remote from the C=C double bond. Nickel-catalyzed deuteroboration experiments using DBPin support a mechanism involving 1,2-insertion of the alkene and subsequent chain-walking, which results in isotopic scrambling.

BODIPYs with Chalcogenophenes at Boron: Synthesis and Properties.

Reported herein are the synthesis and characterization of BODIPYs bearing heterocycles at boron. To synthesize this series, various chalcogenophenes (furan, thiophene, selenophene, and tellurophene) were lithiated and then used as nucleophiles to attack the boron center of a parent F-BODIPY. Compounds in the series were compared with respect to their photophysical and structural properties, and trends were discussed. By virtue of the "heavy atom effect", as the mass of the heterocycle appended to the BODIPY core increases, compounds exhibit a higher singlet oxygen quantum yield. The BODIPY with tellurophene at boron exhibits the highest quantum yield (ΦΔ = 0.68) in the series and reduced emission (Φf = 0.01).

Disturbance of intermolecular forces: eutectics as a new tool for the preparation of vapor-phase deposition precursors.

The volatile bis(tert-butylimido)dichloromolybdenum(VI) compounds, (tBuN)2MoCl2·dad (dad = 1,4-di-tert-butyl-1,3-diazabutadiene) (1) and [(tBuN)2MoCl(µ-Cl)·(tBuNH2)]2 (2), form a eutectic, with a two to one composition (χ2 = 0.33). A decrease of 40 °C in the melting temperature has been observed between the eutectic mixture and the pure compounds. We have isolated a co-crystal of (tBuN)2MoCl2·dme (dme = 1,2-dimethoxyethane) (3) and 2, also in a two to one ratio, which serves as a structural model for such mixtures. The lower melting point of carefully chosen eutectic mixtures can offer more consistent precursor delivery in deposition processes.

The Mental Health of Emerging Adults: Hostile Home Environments and COVID-19.

Purpose: Due to shifts in societal and educational expectations alongside the COVID-19 pandemic, many emerging adults live with their family of origin for extended periods of time. Little is known about patterns of parent-perpetrated maltreatment in emerging adulthood. Therefore, this study evaluates the relation between forms of parent-perpetrated maltreatment, including economic abuse, and COVID stress, on symptoms of depression, anxiety, and traumatic stress. Method: 423 emerging adults who were enrolled in college in the United States in March of 2020 were recruited via MTurk to complete an online survey. An age-related COVID questionnaire and six empirically validated measures assess levels of COVID-19 exposure, lifetime maltreatment, economic abuse, and mental health status. Results: 13.0% of participants reported maltreatment that most recently occurred over the age of 18 in their household of origin. Mean COVID stress level was found to be significantly higher in the Maltreated Over 18 group compared to the Never Maltreated group (t(345) = -3.03, p = 0.003), and in the Maltreated Under 18 group compared to the Never Maltreated group (t(346) = -3.20, p = 0.002). In accounting for the contribution of demographic variables, maltreatment chronicity, economic abuse, and COVID stress, our model predicted 38.6% of variance in depression symptoms, 37.2% of variance in anxiety symptoms, and 42.9% of variance in traumatic stress. Conclusions: Findings indicate need for increased maltreatment screenings within the emerging adult population and calls for age-specific interventions to address the mental health disparities experienced by emerging adults with maltreatment histories.

Tetra-µ-acetato-κ8 O:O'-bis-[(3-chloro-pyridine-κN)ruthenium(II,III)](Ru-Ru) hexa-fluorido-phosphate 1,2-di-chloro-ethane monosolvate.

The title compound, [Ru2(µ-O2CCH3)4(C5H4ClN)2]PF6·C2H4Cl2, was obtained via a rapid substitution reaction of 3-chloro-pyridine for water in [Ru2(µ-O2CCH3)4(H2O)2]PF6 in 2-propanol and subsequent crystallization from a di-chloro-ethane solution. The cationic diruthenium(II,III) tetra-acetate core lies on a crystallographic inversion center with Ru-Ru and Ru-N bond lengths of 2.2738 (3) and 2.2920 (17) Å, respectively. The Ru-Ru-N bond angle is close to linear at 176.48 (4)°, and a significant π-stacking inter-action of 3.5649 (16) Šis seen between overlapping pyridine rings of adjacent cations.

Synthesis of 5'-Thymidine-Conjugated Formylphenylboronic Acids as Potential Lysine Targeting Iminoboronate Reversible Covalent Enzyme Probes.

The design of reversible-covalent molecules to selectively target the ε-amino functionality of lysine residues in enzymes or proteins is a highly desirable goal. Herein, we describe synthetic methodology used to prepare a series of 5'-thymidine-linked formylphenylboronic acids as probes to interrogate sugar nucleotide processing enzymes that recognize thymidine. The first synthetic strategy mitigated the need for protecting group manipulations of thymidine by capitalizing upon the straightforward preparation, isolation, and reactivity of 5'-azidothymidine. An alkyne cycloaddition partner was installed through either a propargyl or ethynyl phenyl ketone derived boronic acid. The second strategy directly linked formylphenylboronic acids to 5-thymidine through an ether linkage installed using Mitsunobu conditions with 3'-O,3-dibenzoylthymidine. Iminoboronate formation was observed with a selected probe.

Origin of Decomposition in a Family of Molybdenum Precursor Compounds.

The bis(tert-butylimido)-molybdenum(VI) framework has been used successfully in the design of vapor-phase precursors for molybdenum-containing thin films, so understanding its thermal behavior is important for such applications. Here, we report the thermal decomposition mechanism for a series of volatile bis(alkylimido)-dichloromolybdenum(VI) adducts with neutral N,N'-chelating ligands, to probe the stability and decomposition pathways for these molecules. The alkyl groups explored were tert-butyl, tert-pentyl, 1-adamantyl, and a cyclic imido (from 2,5-dimethylhexane-2,5-diamine). We also report the synthesis of the new tert-octyl imido adducts, (tOctN)2MoCl2·L (L = N,N,N',N'-tetramethylethylenediamine or 2,2'-bipyridine), which have been fully characterized by spectroscopic techniques as well as single-crystal X-ray diffraction and thermal analysis. We found that the decomposition of all compounds follows the same general pathway, proceeding first by the dissociation of the chelating ligand to give the coordinatively unsaturated species (RN)2MoCl2. Subsequent dimerization results in either an imido bridged adduct, [(RN)Mo(µ-NR)Cl2]2, or a chloride bridged adduct, [(RN)2Mo(µ-Cl)Cl]2, depending on the size of the R group. The dimeric species then likely undergoes an intramolecular γ-hydrogen transfer to yield a nitrido-amido adduct, (RHN)MoNCl2, and an alkene. Ultimately, the resulting molybdenum species appears to decompose into free tert-alkylamine and Mo2N or Mo2C. The thermolysis reactions have been monitored using 1H NMR spectroscopy, and the volatile decomposition products were analyzed using gas chromatography-mass spectrometry. A key intermediate has also been detected using electron ionization high-resolution mass spectrometry. Finally, a detailed computational investigation supports the mechanism outlined above and helps explain the relative stabilities of different N,N'-chelated bis(alkylimido)-dichloromolybdenum(VI) adducts.

Spinal cord injury and pregnancy.

Pregnancy in women with spinal cord injury is considered high risk because it may exacerbate many of their existing problems, including autonomic dysreflexia, spasms, decubitus ulcers, urinary tract infections and respiratory infections. Due to the relative rarity of spinal cord injury in the general obstetric population, clinicians often lack familiarity of these specific problems and the women themselves are usually more experienced in their own management than their obstetric team. However, studies have demonstrated that pregnancy outcomes are generally good with appropriate and experienced obstetric care. In this review, we examine the available literature and provide advice on pre-conception counselling and the antenatal, intrapartum and postnatal management of pregnant women with spinal cord injury.

Thermal Stability and Decomposition Pathways in Volatile Molybdenum(VI) Bis-imides.

The vapor deposition of many molybdenum-containing films relies on the delivery of volatile compounds with the general bis(tert-butylimido)molybdenum(VI) framework, both in atomic layer deposition and chemical vapor deposition. We have prepared a series of (tBuN)2MoCl2 adducts using neutral N,N'-chelates and investigated their volatility, thermal stability, and decomposition pathways. Volatility has been determined by thermogravimetric analysis, with the 1,4-di-tert-butyl-1,3-diazabutadiene adduct (5) found to be the most volatile (1 Torr of vapor pressure at 135 °C). Thermal stability was measured primarily using differential scanning calorimetry, and the 1,10-phenanthroline adduct (4) was found to be the most stable with an onset of decomposition of 303 °C. We have also investigated molybdenum compounds with other alkyl-substituted imido groups: these compounds all follow a similar decomposition pathway, γ-H activation, with varying reaction barriers. The tert-pentyl, 1-adamantyl, and a cyclic imido (from 2,5-dimethylhexane-2,5-diamine) were systematically studied to probe the kinetics of this pathway. All of these compounds have been fully characterized, including via single-crystal X-ray diffraction, and a total of 19 new structures are reported.

Mapping Dual-Base-Enabled Nickel-Catalyzed Aryl Amidations: Application in the Synthesis of 4-Quinolones.

The C-N cross-coupling of (hetero)aryl (pseudo)halides with NH substrates employing nickel catalysts and organic amine bases represents an emergent strategy for the sustainable synthesis of (hetero)anilines. However, unlike protocols that rely on photoredox/electrochemical/reductant methods within NiI/III cycles, the reaction steps that comprise a putative Ni0/II C-N cross-coupling cycle for a thermally promoted catalyst system using organic amine base have not been elucidated. Here we disclose an efficient new nickel-catalyzed protocol for the C-N cross-coupling of amides and 2'-(pseudo)halide-substituted acetophenones, for the first time where the (pseudo)halide is chloride or sulfonate, which makes use of the commercial bisphosphine ligand PAd2-DalPhos (L4) in combination with an organic amine base/halide scavenger, leading to 4-quinolones. Room-temperature stoichiometric experiments involving isolated Ni0, I, and II species support a Ni0/II pathway, where the combined action of DBU/NaTFA allows for room-temperature amide cross-couplings.

Introducing the Tellurophene-Appended BODIPY: PDT Agent with Mass Cytometry Tracking Capabilities.

The synthesis and characterization of the first BODIPY appended to the five-membered heterocylic tellurophene [Te] moiety is reported. By incorporating tellurophene at the meso position, the tellurophene-appended boron-dipyrromethene dye (BODIPY) acts as a multimodal agent, becoming a potent photosensitizer with a mass cytometry tag. To synthesize the compound, we developed a method to enable late-stage Suzuki-Miyaura coupling by preparing and isolating tellurophene-2-BPin in a one-step procedure from the parent tellurophene. Coupling to a meso-substituted BODIPY functionalized with a pendant aryl bromide provides the desired tellurophene-appended BODIPY. This compound demonstrated a singlet oxygen quantum yield of 0.26 ± 0.01 and produced a light dose-dependent cytotoxicity with nanomolar IC50 values against 2D cultured HeLa cells and high efficacy against 3D cultured HeLa tumor spheroids, proving to be a strong photosensitizer. The presence of the tellurophene moiety could be detected using mass cytometry, thus showcasing the ability of a tellurophene-appended BODIPY as a novel photodynamic-therapy-mass-cytometry theranostic agent.

Simple Ion-Gas Mixtures as a Source of Key Molecules Relevant to Prebiotic Chemistry.

Very simple chemistry can result in the rapid and high-yield production of key prebiotic inorganic molecules. The two reactions investigated here involve such simple systems, (a) carbon disulfide (CS2) and acetate (CH3COO¯) and (b) sulfur dioxide (SO2) and formate (HCOO¯). They have been carried out under non-aqueous conditions, either in an organic solvent or with a powdered salt exposed to the requisite gas. Under such dry conditions the first reaction generated the thioacetate anion [CH3COS]¯ while the second produced the radical [SO2·]¯anion. Anhydrous conditions are not rare and may have arisen on the early earth at sites where an interface between different phases (liquid/gas or solid/gas) could be generated. This is one way to rationalize the formation of molecules and ions (such as we have produced) necessary in the prebiotic world. Interpretation of our results provides insight into scenarios consistent with the more prominent theories of abiogenesis.

Delay in the induction of labour process: a retrospective cohort study and computer simulation of maternity unit workload.

OBJECTIVES: Delay in the induction of labour (IOL) process is associated with poor patient experience and adverse perinatal outcome. Our objective was to identify factors associated with delay in the IOL process and develop interventions to reduce delay. DESIGN AND SETTINGS: We performed a retrospective cohort study of maternity unit workload in a large UK district general hospital. Electronic hospital records were used to quantify delay in the IOL process and linear regression analysis was performed to assess significant associations between delay and potential causative factors. A novel computer maternity unit simulation model, MUMSIM (Maternity Unit Management SIMulation), was developed using real-world data and interventions were tested to identify those associated with a reduction in delay. PARTICIPANTS: All women giving birth at Stoke Mandeville Hospital, Buckinghamshire National Health Service (NHS) Trust in 2018 (n=4932). PRIMARY OUTCOME MEASURE: Delay in the IOL process of more than 12 hours. RESULTS: The retrospective analysis of real-world maternity unit workload showed 30% of women had IOL and of these, 33% were delayed >12 hours with 20% delayed >24 hours, 10% delayed >48 hours and 1.3% delayed >72 hours. Delay was significantly associated with the total number of labouring women (p=0.008) and the number of booked IOL (p=0.009) but not emergency IOL, spontaneously labouring women or staffing shortfall. The MUMSIM computer simulation predicted that changing from slow release 24-hour prostaglandin to 6-hour prostaglandin for primiparous women would reduce delay by 4% (p<0.0001) and that additional staffing interventions could significantly reduce delay up to 17.9% (p<0.0001). CONCLUSIONS: Planned obstetric workload of booked IOL is associated with delay rather than the unpredictable workload of women in spontaneous labour or emergency IOL. We present a novel maternity unit computer simulation model, MUMSIM, which allows prediction of the impact of interventions to reduce delay.

Short syntheses of 1-substituted dibenzothiophene derivatives.

The 1-substituted dibenzothiophene motif is an unusual substitution pattern that has previously been accessed via a multi-step synthesis. We demonstrate a simple one-pot preparation of 1-lithiodibenzothiophene from commercial materials via a cascade of two benzyne additions and conversion to several derivatives by addition of electrophiles. A chiral amine containing the 1-dibenzothiophene motif was also prepared. This work avoids the use of precious metals or tert-butyllithium and is much shorter and more convenient than existing routes to 1-substituted dibenzothiophenes.

Heavy Metals Make a Chain: A Catenated Bismuth Compound.

Catenation is common for the light main-group elements whereas it is rare for the heavy elements. Herein, we report the first example of a neutral molecule containing a Bi4 chain. It is prepared in a one-step reaction between bismuth trichloride and bis(diisopropylphosphino)amine in methanol suspension. The same reaction carried out in dichloromethane gives quite different products. All products have been characterized spectroscopically and using single-crystal X-ray analysis.

Air and water stable secondary phosphine oxides as diazaphospholene precatalysts.

Air-stable secondary phosphine oxides (SPOs) are readily formed from diazaphospholene bromides. In the presence of pinacolborane, these SPOs are transformed into catalytically active diazaphospholene hydrides. A silyl triflate transforms the SPOs into phosphenium triflates. The use of diazaphospholene SPOs as reduction reaction precatalysts was validated by imine reduction, conjugate reduction, pyridine hydroboration, and asymmetric reduction.

Synthesis, properties and reactivity of BCl2 aza-BODIPY complexes and salts of the aza-dipyrrinato scaffold.

The synthesis and characterisation of the BCl2-chelated complexes of both archetypal aza-dipyrrin sub-types are presented. A stepwise halogen exchange, leading to a mixed-halide Cl-B-F intermediate, is implicated in the conversion of F-aza-BODIPYs to Cl-aza-BODIPYs upon treatment with BCl3. The utility of the Cl-aza-BODIPY scaffold to facilitate substitutions at boron is demonstrated under mild conditions through treatment with aryl Grignard reagents. Additionally, the lability of the B-Cl bond enables facile removal of the BCl2 group, i.e. deprotection of F-aza-BODIPYs, under aqueous conditions. Three aza-dipyrrin HX salts were also synthesised and characterised. The pKa of the protonated aza-dipyrrin was determined to be 4, thereby providing insight regarding the storage and stability of such species.

Vaginal delivery is safely achieved in pregnancies complicated by spinal cord injury: a retrospective 25-year observational study of pregnancy outcomes in a national spinal injuries centre.

BACKGROUND: Women with spinal cord injuries (SCI) represent a high risk population during pregnancy with comparatively few studies in the literature regarding their management and pregnancy outcomes, due to the relative rarity of the condition. Our objective was to assess pregnancy outcomes in women with spinal cord injury. METHODS: We performed a retrospective observational study of pregnancy outcomes by reviewing maternity records of all pregnant women with SCI attending the National Spinal Injury Centre at Buckinghamshire NHS Trust between 1991 and 2016. The outcome measures were Maternal demographic data, antenatal complications, method of anaesthetic, intrapartum data (gestation at delivery, onset of labour, mode of delivery, indication for obstetric intervention) and neonatal outcomes (low birth weight, stillbirth, neonatal death). RESULTS: Fifty women with a total of 68 pregnancies were identified. Five patients sustained SCI during pregnancy and the remaining 63 pregnancies were conceived at least 1 year after SCI, of which 45 pregnancies had a SCI at T10 or above (73%) and 23 pregnancies at T11 or below (27%). The most common antenatal complications in SCI patients were worsening of spasms (38%) and urinary tract infection (24%). Preterm delivery occurred in 18% of women. Vaginal delivery was achieved in 77% of pregnancies, including 14% instrumental delivery rate and 23% Caesarean delivery rate. CONCLUSIONS: Our findings support the current evidence that pregnancy outcomes are generally successful and that vaginal delivery can be safely achieved in the majority of women, independent of the level of SCI.