Trirhenium(III) cluster alkyls. Synthesis of tertiary phosphine adducts; cleavage to rhenium-(III) and -(II) dimers; reactions with carbon monoxide, nitric oxide, and hydrogen chloride. X-Ray structural determinations of hexamethylbis(diethylphenylphosphine)tri-µ-methyl-triangulo-trirhenium(III) and tri-µ-chloro-(N-nitroso-N-trimethylsilyl-methylhydroxylaminato)pentakis(trimethylsilylmethyl)-triangulo-tri-rhenium(III)

Author(s):  
Peter Edwards ◽  
Konstantinos Mertis ◽  
Geoffrey Wilkinson ◽  
Michael B. Hursthouse ◽  
K. M. Abdul Malik
1977 ◽  
Vol 1 (1) ◽  
pp. 25-32 ◽  
Author(s):  
P.A. Zhdan ◽  
G.K. Boreskov ◽  
A.I. Boronin ◽  
A.P. Schepelin ◽  
W.F. Egelhoff ◽  
...  

2020 ◽  
Author(s):  
Konstantin Khivantsev ◽  
Libor Kovarik ◽  
Nicholas R. Jaegers ◽  
János Szanyi ◽  
Yong Wang

<p>Atomically dispersed Pd +2 cations with ultra-dilute loading of palladium (0.005-0.05 wt%) were anchored on anatase titania and characterized with FTIR, microscopy and catalytic tests. CO infrared adsorption produces a sharp, narrow mono-carbonyl Pd(II)-CO band at ~2,130 cm<sup>-1</sup> indicating formation of highly uniform and stable Pd+2 ions on anatase titania. The 0.05 wt% Pd/TiO<sub>2</sub> sample was evaluated for methane combustion under dry and wet (industrially relevant) conditions in the presence and absence of carbon monoxide. Notably, we find the isolated palladium atoms respond dynamically upon oxygen concentration modulation (switching-on and switching off). When oxygen is removed from the wet methane stream, palladium ions are reduced to metallic state by methane and catalyze methane steam reforming instead of complete methane oxidation. Re-admission of oxygen restores Pd<sup>+2</sup> cations and switches off methane steam reforming activity. Moreover, 0.05 wt% Pd/TiO<sub>2</sub> is a competent CO oxidation catalyst in the presence of water steam with 90% CO conversion and TOF ~ 4,000 hr<sup>-1</sup> at 260 ⁰C. </p><p>More importantly, we find that diluting 0.05 wt% Pd/titania sample with titania to ultra-low 0.005 wt% palladium loading produces a remarkably active material for nitric oxide reduction with carbon monoxide under industrially relevant conditions with >90% conversion of nitric oxide at 180 ⁰C (~460 ppm NO and 150 L/g*hr flow rate in the presence of >2% water steam) and TOF ~6,000 hr<sup>-1</sup>. Pd thus outperforms state-of-the-art rhodium containing catalysts with (15-20 times higher rhodium loading; rhodium is ~ 3 times more expensive than palladium). Furthermore, palladium catalysts are more selective towards nitrogen and produce significantly less ammonia relative to the more traditional rhodium catalysts due to lower Pd amount nd lower water-gas-shift activity. Our study is the first example of utilizing ultra-low (0.05 wt% and less) noble metal (Pd) amounts to produce heterogeneous catalysts with extraordinary activity for nitric oxide reduction. This opens up a pathway to study other Pd, Pt and Rh containing materials with ultra-low loadings of expensive noble metals dispersed on titania or titania-coated oxides for industrially relevant nitric oxide abatement.</p>


1992 ◽  
Vol 89 (23) ◽  
pp. 11141-11145 ◽  
Author(s):  
K. McMillan ◽  
D. S. Bredt ◽  
D. J. Hirsch ◽  
S. H. Snyder ◽  
J. E. Clark ◽  
...  

2021 ◽  
Vol 80 (Suppl 1) ◽  
pp. 1422.3-1423
Author(s):  
T. Hoffmann ◽  
P. Oelzner ◽  
F. Marcus ◽  
M. Förster ◽  
J. Böttcher ◽  
...  

Background:Interstitial lung disease (ILD) in inflammatory rheumatic diseases (IRD) is associated with increased mortality. Moreover, the lung is one of the most effected organs on IRD. Consequently, screening methods were required to the detect ILD in IRD.Objectives:The objective of the following study is to evaluate the diagnostic value of lung function test, chest x-ray and HR-CT of the lung in the detection of ILD at the onset of IRD.Methods:The study is designed as a case-control study and includes 126 patients with a newly diagnosed IRD. It was matched by gender, age and the performance of lung function test and chest x-ray. The sensitivity and specificity were verified by crosstabs and receiver operating characteristic (ROC) curve analysis. The study cohort was divided in two groups (ILD group: n = 63 and control group: n = 63). If possible, all patients received a lung function test and optional a chest x-ray. Patients with pathological findings in the screening tests (chest x-ray or reduced diffusing capacity for carbon monoxide (DLCO) < 80 %) maintained a high-resolution computer tomography (HR-CT) of the lung. Additionally, an immunological bronchioalveolar lavage was performed in the ILD group as gold standard for the detection of ILD.Results:The DLCO (< 80 %) revealed a sensitivity of 83.6 % and specificity of 45.8 % for the detection of ILD. Other examined parameter of lung function test showed no sufficient sensitivity as screening test (FVC = Forced Vital Capacity, FEV1 = Forced Expiratory Volume in 1 second, TLC = Total Lung Capacity, TLCO = Transfer factor of the Lung for carbon monoxide). Also, a combination of different parameter did not increase the sensitivity. The sensitivity and specificity of chest x-ray for the verification of ILD was 64.2 % versus 73.6 %. The combination of DLCO (< 80 %) and chest x-ray showed a sensitivity with 95.2 % and specificity with 38.7 %. The highest sensitivity (95.2 %) and specificity (77.4 %) was observed for the combination of DLCO (< 80 %) and HR-CT of the lung.Conclusion:The study highlighted that a reduced DLCO in lung function test is associated with a lung involvement in IRD. DLCO represented a potential screening parameter for lung manifestation in IRD. Especially patients with suspected vasculitis should receive an additional chest x-ray. Based on the high sensitivity of DLCO in combination with chest x-ray or HR-CT for the detection of ILD in IRD, all patients with a reduced DLCO (< 80%) should obtained an imaging of the lung.Disclosure of Interests:None declared


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