Pentamethylcyclopentadienyl osmium complexes that contain diazoalkane, dioxygen and allenylidene ligands: preparation and reactivity

Diazoalkane complexes [Os(η5-C5Me5)(N2CAr1Ar2)(PPh3){P(OR)3}]BPh4 (1, 2) [R = Me (1), Et (2); Ar1 = Ar2 = Ph (a); Ar1 = Ph, Ar2 = p-tolyl (b); Ar1Ar2 = C12H8 (fluorenyl) (c)] were prepared by reacting bromo-compounds OsBr(η5-C5Me5)(PPh3){P(OR)3} with an excess of diazoalkane in ethanol. The treatment of diazoalkane complexes 1 and 2 with acetylene under mild conditions (1 atm, RT) led to dipolar (3 + 2) cycloaddition affording 3H-pyrazole derivatives [Os(η5-C5Me5)(η1-[upper bond 1 start]N[double bond, length as m-dash]NC(C12H8)CH[double bond, length as m-dash]C[upper bond 1 end]H)(PPh3){P(OR)3}]BPh4 (6, 7) [R = Me (6), Et (7)] whereas reactions with terminal alkynes R1C[triple bond, length as m-dash]CH (R1 = Ph, p-tolyl, COOMe) gave vinylidene derivatives [Os(η5-C5Me5){[double bond, length as m-dash]C[double bond, length as m-dash]C(H)R1}(PPh3){P(OR)3}]BPh4 (8b–d, 9b–d) [R = Me (8), Et (9); R1 = Ph (b), p-tolyl (c), COOMe (d)]. Exposure to air of dichloromethane solutions of complexes 1 and 2 produced dioxygen derivatives [Os(η5-C5Me5)(η2-O2)(PPh3){P(OR)3}]BPh4 (10, 11) [R = Me (10), Et (11)]. Allenylidene [Os][double bond, length as m-dash]C[double bond, length as m-dash]C[double bond, length as m-dash]CR1R2 (12–14) [R1 = R2 = Ph (12, 13); R1 = Ph, R2 = Me (14)], vinylvinylidene [Os][double bond, length as m-dash]C[double bond, length as m-dash]C(H)C(Ph)[double bond, length as m-dash]CH2 (15) and 3-hydroxyvinylidene [Os][double bond, length as m-dash]C[double bond, length as m-dash]C(H)C(H)R2(OH) (16, 17) [R2 = Ph (16), H (17)] derivatives were also prepared. The vinylidene complex [Os(η5-C5Me5)([double bond, length as m-dash]C[double bond, length as m-dash]CH2)(PPh3){P(OMe)3}]BPh4 (8a) reacted with PPh3 to afford the alkenylphosphonium derivative [Os(η5-C5Me5){η1-C(H)[double bond, length as m-dash]C(H)PPh3}(PPh3){P(OMe)3}]BPh4 (18) whereas vinylidene complexes 8 and 9 reacted with water leading to the hydrolysis of the alkyne and the formation of carbonyl complexes [Os(η5-C5Me5)(CO)(PPh3){P(OR)3}]BPh4 (19, 20). The complexes were characterised by spectroscopic data (IR and NMR) and by X-ray crystal structure determination of [Os(η5-C5Me5){[double bond, length as m-dash]C[double bond, length as m-dash]C(H)p-tolyl}(PPh3){P(OEt)3}]BPh4 (9c), [Os(η5-C5Me5)(η2-O2)(PPh3){P(OMe)3}]BPh4 (10) and [Os(η5-C5Me5)(CO)(PPh3){P(OMe)3}]BPh4 (19)

Micromorphological and chemical elucidation ofthe degradation mechanisms of birch barkarchaeological artefacts

Introduction: Since ancient times, the unique properties of birch barks (Betula genus) have made them a material of choice for producing both everyday-life and artistic objects. Yet archaeological birch bark artefacts are rare, and little is known about the chemical transformations undergone by bark (chemically composed mainly of suberin and triterpenes) in archaeological contexts. Understanding the chemical modifications induced by ageing is essential for selecting suitable preservation and conservation approaches. Thus, the main aim of this research is to assess the preservation and state of degradation of archaeological findings made of birch bark: a Neolithic bow case recovered from a melting ice patch in the Bernese Alps (Switzerland) and a waterlogged birch bark vessel discovered at Moossee Lake (Canton of Bern, Switzerland). Scanning electron microscopy (SEM) and gas chromatography/mass spectrometry (GC/MS) were used to obtain information at micro-morphological and molecular levels on the state of degradation of the birch bark findings. GC/MS analysis followed two different sample preparations, alkaline hydrolysis and solvent extraction, in order to investigate respectively the hydrolysable and soluble constituents, and to test whether part of the suberin structure was depolymerised by the long period of burial. Results and conclusions: SEM investigations on archaeological birch bark samples have shown that the extent of degradation of the microstructure is much higher in waterlogged birch bark than in birch bark preserved in ice. GC/MS analysis revealed that at a molecular level, the birch bark was quite well preserved. In both the archaeological environments, ice patch and lake water, various reactions had taken place leading to the depletion of reactive and sensitive compounds such as unsaturated acids and epoxy-compounds. In addition, archaeological birch bark had undergone depolymerization and oxidation reactions leading to the appearance of free suberin monomers and of oxidised triterpenes (betulone and lupenone). GC/MS data also seems to suggest that the birch bark preserved in the waterlogged site had a more pronounced degradation both in terms of oxidation and depolymerisation

Cohort profile: The Observational cohort for the study of DOlutegravir in Antiretroviral Combination REgimens (ODOACRE)

The Observational cohort for the study of DOlutegravir in Antiretroviral Combination REgimens (ODOACRE) cohort was established in Italy in 2016 to evaluate the overall efficacy and tolerability of dolutegravir (DTG)-based antiretroviral (ARV) regimens in clinical practice

Linguistic profile automated characterisation in pluripotential clinical high-risk mental state (CHARMS) conditions: methodology of a multicentre observational study

Introduction: Language is usually considered the social vehicle of thought in intersubjective communications. However, the relationship between language and high- order cognition seems to evade this canonical and unidirectional description (ie, the notion of language as a simple means of thought communication). In recent years, clinical high at-risk mental state (CHARMS) criteria (evolved from the Ultra-High-Risk paradigm) and the introduction of the Clinical Staging system have been proposed to address the dynamicity of early psychopathology. At the same time, natural language processing (NLP) techniques have greatly evolved and have been successfully applied to investigate different neuropsychiatric conditions. The combination of at-risk mental state paradigm, clinical staging system and automated NLP methods, the latter applied on spoken language transcripts, could represent a useful and convenient approach to the problem of early psychopathological distress within a transdiagnostic risk paradigm. Methods and analysis: Help-seeking young people presenting psychological distress (CHARMS+/− and Clinical Stage 1a or 1b; target sample size for both groups n=90) will be assessed through several psychometric tools and multiple speech analyses during an observational period of 1-year, in the context of an Italian multicentric study. Subjects will be enrolled in different contexts: Department of Neuroscience, Rehabilitation, Ophthalmology, Genetics, Maternal and Child Health (DINOGMI), Section of Psychiatry, University of Genoa—IRCCS Ospedale Policlinico San Martino, Genoa, Italy; Mental Health Department—territorial mental services (ASL 3—Genoa), Genoa, Italy; and Mental Health Department—territorial mental services (AUSL—Piacenza), Piacenza, Italy. The conversion rate to full-blown psychopathology (CS 2) will be evaluated over 2 years of clinical observation, to further confirm the predictive and discriminative value of CHARMS criteria and to verify the possibility of enriching them with several linguistic features, derived from a fine-grained automated linguistic analysis of speech. Ethics and dissemination: The methodology described in this study adheres to ethical principles as formulated in the Declaration of Helsinki and is compatible with International Conference on Harmonization (ICH)-good clinical practice. The research protocol was reviewed and approved by two different ethics committees (CER Liguria approval code: 591/2020—id.10993; Comitato Etico dell’Area Vasta Emilia Nord approval code: 2022/0071963). Participants will provide their written informed consent prior to study enrolment and parental consent will be needed in the case of participants aged less than 18 years old. Experimental results will be carefully shared through publication in peer- reviewed journals, to ensure proper data reproducibility. Trial registration number DOI:10.17605/OSF.IO/BQZTN

How future surgery will benefit from SARS-COV-2-related measures: a SPIGC survey conveying the perspective of Italian surgeons

COVID-19 negatively affected surgical activity, but the potential benefits resulting from adopted measures remain unclear. The aim of this study was to evaluate the change in surgical activity and potential benefit from COVID-19 measures in perspective of Italian surgeons on behalf of SPIGC. A nationwide online survey on surgical practice before, during, and after COVID-19 pandemic was conducted in March-April 2022 (NCT:05323851). Effects of COVID-19 hospital-related measures on surgical patients' management and personal professional development across surgical specialties were explored. Data on demographics, pre-operative/peri-operative/post-operative management, and professional development were collected. Outcomes were matched with the corresponding volume. Four hundred and seventy-three respondents were included in final analysis across 14 surgical specialties. Since SARS-CoV-2 pandemic, application of telematic consultations (4.1% vs. 21.6%; p < 0.0001) and diagnostic evaluations (16.4% vs. 42.2%; p < 0.0001) increased. Elective surgical activities significantly reduced and surgeons opted more frequently for conservative management with a possible indication for elective (26.3% vs. 35.7%; p < 0.0001) or urgent (20.4% vs. 38.5%; p < 0.0001) surgery. All new COVID-related measures are perceived to be maintained in the future. Surgeons' personal education online increased from 12.6% (pre-COVID) to 86.6% (post-COVID; p < 0.0001). Online educational activities are considered a beneficial effect from COVID pandemic (56.4%). COVID-19 had a great impact on surgical specialties, with significant reduction of operation volume. However, some forced changes turned out to be benefits. Isolation measures pushed the use of telemedicine and telemetric devices for outpatient practice and favored communication for educational purposes and surgeon-patient/family communication. From the Italian surgeons' perspective, COVID-related measures will continue to influence future surgical clinical practice

Half-Sandwich Complexes with Azo Ligand: Preparation and Reactivity

Complessi azinici del tipo RuCl(\u3b76-p-cymene){\u3ba1-[N=C(H)R1]-N=C(H)R1}L]BPh4 and [Ru(\u3b75-C5H5){\u3ba1-[N=C(H)R1]-N=C(H)R1}(PPh3){P(OMe)3}]BPh4 [L= P(OMe)3, P(OEt)3, PPh(OEt)2, PiPr3; R1= Ph, 4-CH3C6H4, 4-CH3OC6H4, Et] sono stati preparati lasciando reagire i cloro complessi precursori con le azine libere R1(H)C=N-N=C(H)R1. A seconda del legante fosfinico utilizzato la reazione tra i complessi precursori stabilizzati da p-cimene RuCl2(\u3b76-p-cymene)L con acetone azina, (CH3)2C=N-N=C(CH3)2, portava alla formazione degli idrazoni complessi [RuCl(\u3b76-p-cymene){NH2N=C(CH3)2}L]BPh4 [L=P(OMe)3, P(OEt)3] o con la chetazina coordinata \u3ba1- [RuCl(\u3b76-p-cymene){\u3ba1-[N=C(CH3)2]N=C(CH3)2}(PiPr3)]BPh4. La reazione della stessa chetazina con il complesso precursore stabilizzato da ciclopentadiene RuCl(\u3b75-C5H5)(PPh3)[P(OR)3] (R= Me, Et) portava invece alla sola formazione degli idrazoni complessi [Ru(\u3b75-C5H5){NH2N=C(CH3)2}(PPh3){P(OMe)3}]BPh4 [R1= Ph, 4-CH3C6H4, C2H5]. Particolarmente interessante di questi ultimi complessi \ue8 la reazione di ossidazione con HgO che porta alla formazione del diazoalcano complesso derivato [Ru(\u3b75-C5H5){N2C(CH3)2}(PPh3){P(OMe)3}]BPh4. Complessi azinici del tipo [OsCl(\u3b76-p-cymene){\u3ba1-[N=C(H)C6H4R1]N=C(H)C6H4R1}{P(OR)3}]-BPh4 e [OsCl(\u3b76-p-cymene){\u3ba1-[N=C(CH3)2]N=C(CH3)2}{P(OR)3}]BPh4 [R = Me, Et; R1 = H , 4-CH3, 2,6-(CH3)2] sono stati preparati reagendo i cloro complessi precursori prima con un equivalente di AgOTf e successivamente con le diverse azine. Curiosamente, in questo caso, i complessi con coordinate le azine \u3ba1- spontaneamente davano in soluzione reazione di ciclizzazione intramolecolare con la formazione dei derivati chelati [Os{\u3ba2-R1C6H3C(H)=N-N=C(H)C6H4R1}(\u3b76-p-cymene){P(OR)3}]BPh4 [R = Me, Et; R1 = H, 4-CH3]. Utilizzando lo stesso metodo sintetico sono stati preparati anche i complessi azinici di rodio, [RhCl(\u3b75-C5Me5){\u3ba1-[N=C(H)Ph]\u2013N=C(H)Ph}L]BPh4 e [Rh{\u3ba2-R1C6H3C(H)=N-N=C(H)C6H4R1}(\u3b75-C5Me5){P(OR)3}]BPh4, and iridio, [IrCl(\u3b75-C5Me5){\u3ba1-[N=C(H)Ph]\u2013N=C(H)Ph}L]BPh4 e [Ir{\u3ba2-R1C6H3-C(H)=N-N=C(H)C6H4R1}(\u3b75-C5Me5){P(OR)3}]BPh4. Curiosamente, molti dei complessi di iridio con le azine coordinate \u3ba2- hanno mosrtrato intressanti propriet\ue0 di fotoluminescenza: l\u2019eccitazione con near-UV e la luce nel violetto portava infatti all\u2019emissione di picchi intorno a 650 nm. Diazoalcani complessi del tipo [Os(\u3b75-C5Me5)(N2CAr1Ar2(PPh3){P(OR)3}]BPh4 sono stati preparati lasciando reagire in soluzione i cloro complessi precursori con i diversi diazoalcani N2=CAr1Ar2 (Ar1=Ar2= Ph; Ar1 = Ph, Ar2 = p-tolyl; Ar1Ar2 = C12H8). Tra le propriet\ue0 studiate da questi nuovi diazoalcano complessi \ue8 particolarmente interessante la reazione di ciclizzazione dipolare (3+2) con l\u2019acetilene, HC\uf0baCH, che porta alla formazione dei 3H-pirazoli derivati. Importanti anche le reazioni di sostituzione con ossigeno, con formazione degli ossigeno complessi derivati in cui l\u2019O2 si coordina side-one, la sostituzione con alchini terminali R1C\uf0baCH, con formazione dei corrispondenti vinilideni complessi, e infine la sostituzione con alcoli propargilici [HC 61CC(OH)R1R2], che porta alla formazione dei corrispondenti idrossi-vinilideni e allenilideni complessi. Le azidi organiche possono coordinarsi a centri metallici in complessi del tipo [Os(\u3b75-C5H5)(\u3ba1-N3R)(PPh3){P(OR1)3}]BPh4. A seconda del gruppo funzionale legato al gruppo N3 dell\u2019azide tuttavia \ue8 possibile ottenere anche altri complessi, dovuti alla decomposizione dell\u2019azide, come ad esempio i complessi imminici derivati [Os(\u3b75-C5H5){\u3ba1-NH=C(R1)Ar}-(PPh3){P(OR)3}]BPh4 (R1 = H, CH3) o i complessi binucleari di azoto [Os(\u3b75-C5H5)(PPh3){P(OMe)3}2(\u3bc-N2)](BPh4)2. Quest\u2019ultimo in particolare \ue8 stato preparato facendo reagire il bromo complesso precursore con fenilazide PhN3.Aldazine complexes of the type [RuCl(\u3b76-p-cymene){\u3ba1-[N=C(H)R1]-N=C(H)R1}L]BPh4 and [Ru(\u3b75-C5H5){\u3ba1-[N=C(H)R1]-N=C(H)R1}(PPh3){P(OMe)3}]BPh4 [L= P(OMe)3, P(OEt)3, PPh(OEt)2, PiPr3; R1= Ph, 4-CH3C6H4, 4-CH3OC6H4, Et] were prepared by allowing the chloro compounds to react with the azine R1(H)C=N-N=C(H)R1. Depending on the nature of the phosphine ligand, the reaction of ketazine (CH3)2C=N-N=C(CH3)2 with chloro compounds RuCl2(\u3b76-p-cymene)L yielded either hydrazone derivatives [RuCl(\u3b76-p-cymene){NH2N=C(CH3)2}L]BPh4 [L=P(OMe)3, P(OEt)3] or \u3ba1-azine complex [RuCl(\u3b76-p-cymene){\u3ba1-[N=C(CH3)2]N=C(CH3)2}(PiPr3)]BPh4, while the reaction of the acetoneazine with the cyclopentadienyl complexes RuCl(\u3b75-C5H5)(PPh3)[P(OR)3] (R= Me, Et) led to the formation of [Ru(\u3b75-C5H5){NH2N=C(CH3)2}(PPh3){P(OMe)3}]BPh4 [R1= Ph, 4-CH3C6H4, C2H5]. Oxidation of these hydrazone derivative with HgO gave dimethyldiazoalkane complex [Ru(\u3b75-C5H5){N2C(CH3)2}(PPh3){P(OMe)3}]BPh4. Half-sandwich azine complexes [OsCl(\u3b76-p-cymene){\u3ba1-[N=C(H)C6H4R1]N=C(H)C6H4R1}{P(OR)3}]-BPh4 and [OsCl(\u3b76-p-cymene){\u3ba1-[N=C(CH3)2]N=C(CH3)2}{P(OR)3}]BPh4 [R = Me, Et; R1 = H , 4-CH3, 2,6-(CH3)2] were prepared by allowing chloro compounds [OsCl2(\u3b76-p-cymene){P(OR)3}] to react first with one equivalent of AgOTf and then with azine. Interestingly in solution \u3ba1-azine complexes undergo metalation reaction, giving chelate derivatives [Os{\u3ba2-R1C6H3C(H)=N-N=C(H)C6H4R1}(\u3b76-p-cymene){P(OR)3}]BPh4 [R = Me, Et; R1 = H, 4-CH3]. Using the same synthetic route were prepared the analogues azine complexes of rhodium, [RhCl(\u3b75-C5Me5){\u3ba1-[N=C(H)Ph]\u2013N=C(H)Ph}L]BPh4 and [Rh{\u3ba2-R1C6H3C(H)=N-N=C(H)C6H4R1}(\u3b75-C5Me5)-{P(OR)3}]BPh4, and iridium, [IrCl(\u3b75-C5Me5){\u3ba1-[N=C(H)Ph]\u2013N=C(H)Ph}L]BPh4 and [Ir{\u3ba2-R1C6H3-C(H)=N-N=C(H)C6H4R1}(\u3b75-C5Me5){P(OR)3}]BPh4. Interestingly, most of the \u3ba2-arylazine derivatives of iridium showed photoluminescence properties upon excitation with near-UV and violet light, with emission peaks at around 650 nm. The photoluminescence features were rationalised according to DFT calculations. Diazoalkane complexes of the type [Os(\u3b75-C5Me5)(N2CAr1Ar2(PPh3){P(OR)3}]BPh4 were prepared by allowing the chloro compounds to react with the diazoalkanes N2=CAr1Ar2 (Ar1=Ar2= Ph; Ar1 = Ph, Ar2 = p-tolyl; Ar1Ar2 = C12H8). Among the properties shown by these complexes, interesting is the dipolar (3+2) cycloaddition with acetylene HC\uf0baCH affording 3-H pyrazole derivatives. Substitution of the diazoalkane ligand also occurs with dioxygen, yielding the \u3ba2-O2 derivatives, with terminal alkynes R1C\uf0baCH yielding vinylidene derivatives and with propargylic alcohols [HC 61CC(OH)R1R2] yielding allenylidene and hydroxyvinylidene derivatives. Half-sandwich fragment [Os(\u3b75-C5H5)(PPh3){P(OR)3}]+ can stabilise organic azide complexes [Os(\u3b75-C5H5)(\u3ba1-N3R)(PPh3){P(OR1)3}]BPh4 and imine derivatives [Os(\u3b75-C5H5){\u3ba1-NH=C(R1)Ar}-(PPh3){P(OR)3}]BPh4 (R1 = H, CH3). The binuclear dinitrogen derivative [Os(\u3b75-C5H5)(PPh3){P(OMe)3}2(\u3bc-N2)](BPh4)2 was prepared from phenylazide PhN3 complexes. The reaction between azides and half-sandwich fragment of the type [IrCl(\u3b75-C5Me5){P(OR1)3}]+ leads to the formation of imino [IrCl(\u3b75-C5Me5){\u3ba1-NH=C(R1)Ar}(PPh3){P(OR)3}]BPh4 (R1= H, CH3; Ar=C6H5, p-tolyl) and amino [IrCl(\u3b75-C5Me5)(NH2Ph){P(OR)3}]BPh4 derivatives. Moreover, changing the reaction condition, the reaction between azides and the dimeric compound [IrCl(\u3bc-Cl)(\u3b75-C5Me5)]2 leads to the formation of both mono- [IrCl2(\u3b75-C5Me5)(\u3ba1-NH=C(R1)Ar)] and di-imine complexes [IrCl(\u3b75-C5Me5)(\u3ba1-NH=C(R1)Ar)2]BPh4 (R1= H, CH3; Ar=C6H5, p-tolyl). Treatment of the fragment [Ir(\u3ba1-Otf)2(\u3b75-C5Me5){P(OR1)3}]+ with azides yield the bis-imine derivatives

Preparation of Half-Sandwich Azine Complexes of Osmium

Half-sandwich azine complexes [OsCl(g6-p-cymene){j1-[N@C(H)C6H4R1]–N@C(H)C6H4R1}{P(OR)3}] BPh4 (1, 2) and [OsCl(g6-p-cymene){j1-[N@C(CH3)2]N@C(CH3)2}{P(OR)3}]BPh4 (3, 4) [R = Me (1, 3), Et (2, 4); R1 = H (a), 4-CH3 (b), 2,6-(CH3)2 (c)] were prepared by allowing chloro compounds [OsCl2(g6-pcymene){P(OR)3}] to react first with one equivalent of AgOTf and then with azine. Instead, treatment of chloro compounds with acetone azine afforded hydrazone derivatives [OsCl(g6-p-cymene){NH2N@ C(CH3)2}{P(OR)3}]BPh4 (5, 6) [R = Me (5), Et (6)]. In solution, j1-azine complexes undergo metalation reaction, giving chelate derivatives (g6-p-cymene){P(OR)3}] BPh4 (7, 8) [R = Me (7), Et (8); R1 = H (a), 4-CH3 (b)]. The complexes were characterised by spectroscopy (IR, NMR) and X-ray crystal structure determination of [OsCl(g6-p-cymene){j1-[N@C(H)Ph]–N@C(H)Ph} {P(OEt)3}]BPh4 (2a)