Preparation and Reactions of [CpOs(CH₃CN)₃]⁺. A Useful Synthetic Intermediate for the Preparation of CpOsL₃ Compounds

A photochemical synthesis of [CpOs(CH3CN)3]+ is reported (Cp = η5-cyclopentadienyl). Photolysis of [CpOs(Bz)]+ (Bz = η6-benzene) in acetonitrile solution gives [CpOs(CH3CN)3]+, but only 30% conversion is achieved before significant photochemically induced decomposition of [CpOs(CH3CN)3]+ occurs. Photolysis of acetonitrile solutions of [CpOs(Bz)]+ that contain biphenyl eliminates this side reaction and allows the high-yield preparation of [CpOs(CH3CN)3]+. Quantum yields for the photodearylation reaction are identical in the presence or absence of biphenyl, suggesting that biphenyl acts as a passive filter, slowing the photochemical decomposition of [CpOs(CH3CN)3]+. [CpOs(CH3CN)3]+ reacts with arenes, CO, and polypyrazolylborate ligands, providing a high-yield route to CpOsL3 compounds under mild conditions. Compounds that were synthesized and fully characterized include [CpOs(η6-anthracene)]PF6, [CpOs(η6-rubrene)]PF6, CpOs(BPz4) (BPz4- = tetrakis(1-pyrazolyl)borate), CpOs(HBPz3) (HBPz3- = hydrotris(1-pyrazolyl)borate), [CpOs(CH3CN)2CO]PF6, and CpOs(CO)2Br. 1H NMR evidence for an additional species ([(CpOs)(CpOs(CH3CN))(μ-η6,η4-anth)]2+) that contains an η6 and an η4 CpOs+ group is presented. Intriguing differences between the reactivity of [CpOs(CH3CN)3]+ and [CpRu(CH3CN)3]+ with rubrene are observed, with the osmium complex showing a remarkable kinetic preference for the naphthacene backbone relative to the pendant phenyl rings

Area method for measuring diaphragm movement in patients with unilateral pleural effusion

Introduction: Ultrasound (US) assessment of diaphragm movement has traditionally been performed using the M-mode function. However, M-mode of left diaphragm is challenged by poor visualization. The Area method is a novel technique for measuring diaphragm movement, which measures the change in intrathoracic area during respiration. So far, the Area method has only been assessed in small and selective cohorts.Aim: This study aimed to evaluate the feasibility of the Area method compared to M-mode in measuring diaphragm movement in a larger cohort of patients with unilateral pleural effusion (UPE).Methods: In a prospective observational study, including patients with UPE diaphragm movement was measured on the side of effusion before and after thoracentesis using both the Area method and M-mode. Outcome was the ability to obtain sufficient US images of the diaphragm.Results: We included 104 patients with UPE, 70 (67%) being right-sided and 48 (46%) fully drained. Concerning right-sided effusions, the two methods were comparable both before and after thoracentesis (69/70 (99%) vs.69/70 (99%), p=1.0 and 64/70 (91%) vs. 62/70 (89%), p=0.41, respectively). In left-sided effusions, sufficient US images were achieved more often using the Area method compared to M-mode before and after thoracentesis (34/34 (100%) vs. 31/34 (91%), p=0.08) and 33/34 (97%) vs. 27/34 (79%), p=0.01, respectively).Conclusions: This study found that the Area-method is a viable alternative to M-mode especially in left-sided effusions.References:Skaarup SH et al, Crit Ultrasound J, 2018Skaarup SH et al, J Bronchol Interv Pulmonol, 2019FootnotesCite this article as Eur Respir J 2022; 60: Suppl. 66, 2080.This article was presented at the 2022 ERS International Congress, in session “-”.This is an ERS International Congress abstract. No full-text version is available. Further material to accompany this abstract may be available at www.ers-education.org (ERS member access only)

Inhaled Corticosteroids in Patients with Chronic Obstructive Pulmonary Disease and Risk of Acquiring Streptococcus pneumoniae Infection. A Multiregional Epidemiological Study

Background: Inhaled corticosteroids (ICS) are associated with an increased risk of clinical pneumonia among patients with chronic obstructive pulmonary disease (COPD). It is unknown whether the risk of microbiologically verified pneumonia such as pneumococcal pneumonia is increased in ICS users. Methods: The study population consists of all COPD patients followed in outpatient clinics in eastern Denmark during 2010-2017. ICS use was categorized into four categories based on accumulated use. A Cox proportional hazard regression model was used adjusting for age, body mass index, sex, airflow limitation, use of oral corticosteroids, smoking, and year of cohort entry. A propensity score matched analysis was performed for sensitivity analyses. Findings:  A total of 21,438 patients were included. Five hundred and eighty-two (2.6%) patients acquired a positive lower airway tract sample with S. pneumoniae during follow-up. In the multivariable analysis ICS-use was associated with a dose-dependent risk of S. pneumoniae as follows: low ICS dose: HR 1.11, 95% CI 0.84 to 1.45, p = 0.5; moderate ICS dose: HR 1.47, 95% CI 1.13 to 1.90, p = 0.004; high ICS dose: HR 1.77, 95% CI 1.38 to 2.29, p < 0.0001, compared to no ICS use. Sensitivity analyses confirmed these results. Interpretation: Use of ICS in patients with severe COPD was associated with an increased and dose-dependent risk of acquiring S. pneumoniae, but only for moderate and high dose. Caution should be taken when administering high dose of ICS to patients with COPD. Low dose of ICS seemed not to carry this risk