scholarly journals Competing C–H and C–F bond activation reactions of a fluorinated olefin at Rh: a fluorido vinylidene complex as an intermediate in an unprecedented dehydrofluorination step

2022 ◽  
Author(s):  
Maria Talavera ◽  
Thomas Braun
Keyword(s):  
Bond Activation ◽  
Complex Model ◽  
Model Studies ◽  
Reaction Intermediate ◽  
Vinylidene Complex

Dehydrofluorination of a fluorinated vinyl ligand takes place after C–H bond activation of Z-1,3,3,3-tetrafluropropene at a rhodium vinyl complex. Model studies support a vinylidene as reaction intermediate for the dehydrofluorination.

scholarly journals Chemoselective C–C σ-Bond Activation of Biphenylene

2020 ◽  
Author(s):  
Richard Y Kong ◽  
Mark Crimmin
Keyword(s):  
Dft Calculations ◽  
Bond Activation ◽  
Strain Analysis ◽  
Molecular Orbitals ◽  
Membered Ring ◽  
P System ◽  
Frontier Molecular Orbitals ◽  
Reaction Intermediate ◽  
Reaction Proceeds

The chemoselective cleavage of an arene ring in biphenylene is reported using an aluminium(I) complex. The reaction proceeds with complete integrity of the central 4-membered ring despite this ring containing the weakest C–C σ-bond in the hydrocarbon scaffold. A reaction intermediate derived from the (4+1) cycloaddition of the aluminium(I) complex to the p-system of biphenylene was isolated. Further experiments and DFT calculations suggest that this intermediate is involved in breaking of the C–C σ-bond. Activation strain analysis was used to understand the origins of the remarkable chemoselectivity of this system. Both the symmetry and diffuseness of the frontier molecular orbitals of the aluminium(I) fragment are implicated in its unusual reactivity with biphenylene.

scholarly journals The Chemoselective C–C σ-Bond Activation of the Arene Ring of Biphenylene

2020 ◽  
Author(s):  
Richard Y Kong ◽  
Mark Crimmin
Keyword(s):  
Dft Calculations ◽  
Bond Activation ◽  
Strain Analysis ◽  
Molecular Orbitals ◽  
Membered Ring ◽  
P System ◽  
Frontier Molecular Orbitals ◽  
Reaction Intermediate ◽  
Reaction Proceeds

The chemoselective cleavage of an arene ring in biphenylene is reported using an aluminium(I) complex. The reaction proceeds with complete integrity of the central 4-membered ring despite this ring containing the weakest C–C σ-bond in the hydrocarbon scaffold. A reaction intermediate derived from the (4+1) cycloaddition of the aluminium(I) complex to the p-system of biphenylene was isolated. Further experiments and DFT calculations suggest that this intermediate is involved in breaking of the C–C σ-bond. Activation strain analysis was used to understand the origins of the remarkable chemoselectivity of this system. Both the symmetry and diffuseness of the frontier molecular orbitals of the aluminium(I) fragment are implicated in its unusual reactivity with biphenylene.

scholarly journals Construction of a numerical groundwater flow model in areas of intense mine drainage, as exemplified by the Olkusz Zinc and Lead Ore Mining Area in southwest Poland

Geologos ◽  
2018 ◽  
Vol 24 (3) ◽  
pp. 237-244
Author(s):  
Kamil Juśko ◽  
Jacek Motyka ◽  
Kajetan d’Obyrn ◽  
Zbigniew Adamczyk
Keyword(s):  
Mine Drainage ◽  
Complex Structure ◽  
Mining Area ◽  
Geological Structure ◽  
Complex Model ◽  
Model Structure ◽  
Model Studies ◽  
Hydrogeological Parameters ◽  
Rock Formations ◽  
Selection Of

Abstract Areas of intense mine drainage that are subjected to numerical modelling require the construction of a complex model structure that will properly reflect actual conditions. This paper presents the process and results of constructing such a structure for the Olkusz Zinc and Lead Ore Mining Area, an area situated in a cone of depression the extent of which reaches 500 km2. This size range calls for a selection of appropriate external boundaries, properly separated from these of the mine drainage area. The complex geological structure of the Olkusz area, associated with considerable variation in the thickness of rock formations, discontinuities of rock levels and occurrence of numerous faults, must be schematised so that calculation layers can be identified. The faults in the study area have to be reflected in the regional model structure, although only those faults that actually affect groundwater flows should be selected. The model structure needs to include detailed recognition and reflection of hydraulic contacts between aquifer levels, together with a selection of hydrogeological parameters that are different for particular formations. Only a complex structure built in such a manner may be the foundation of further model studies.

scholarly journals Chemoselective C–C σ-Bond Activation of Biphenylene

2020 ◽  
Author(s):  
Richard Y Kong ◽  
Mark Crimmin
Keyword(s):  
Dft Calculations ◽  
Bond Activation ◽  
Strain Analysis ◽  
Molecular Orbitals ◽  
Membered Ring ◽  
P System ◽  
Frontier Molecular Orbitals ◽  
Reaction Intermediate ◽  
Reaction Proceeds

The chemoselective cleavage of an arene ring in biphenylene is reported using an aluminium(I) complex. The reaction proceeds with complete integrity of the central 4-membered ring despite this ring containing the weakest C–C σ-bond in the hydrocarbon scaffold. A reaction intermediate derived from the (4+1) cycloaddition of the aluminium(I) complex to the p-system of biphenylene was isolated. Further experiments and DFT calculations suggest that this intermediate is involved in breaking of the C–C σ-bond. Activation strain analysis was used to understand the origins of the remarkable chemoselectivity of this system. Both the symmetry and diffuseness of the frontier molecular orbitals of the aluminium(I) fragment are implicated in its unusual reactivity with biphenylene.

“In vitro” and in Animal Model Studies on a Double Virus- Inactivated Factor VIII Concentrate

1995 ◽  
Vol 74 (03) ◽  
pp. 868-873 ◽  
Author(s):  
Silvana Arrighi ◽  
Roberta Rossi ◽  
Maria Giuseppina Borri ◽  
Vladimir Lesnikov ◽  
Marina Lesnikov ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Animal Model ◽  
Factor Viii ◽  
Hepatitis A ◽  
Hepatitis A Virus ◽  
Virus Inactivation ◽  
Enveloped Viruses ◽  
Model Studies ◽  
Heat Treated

SummaryTo improve the safety of plasma derived factor VIII (FVIII) concentrate, we introduced a final super heat treatment (100° C for 30 min) as additional virus inactivation step applied to a lyophilized, highly purified FVIII concentrate (100 IU/mg of proteins) already virus inactivated using the solvent/detergent (SID) method during the manufacturing process.The efficiency of the super heat treatment was demonstrated in inactivating two non-lipid enveloped viruses (Hepatitis A virus and Poliovirus 1). The loss of FVIII procoagulant activity during the super heat treatment was of about 15%, estimated both by clotting and chromogenic assays. No substantial changes were observed in physical, biochemical and immunological characteristics of the heat treated FVIII concentrate in comparison with those of the FVIII before heat treatment.

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