In this paper the C--F bond activation of polyfluoroaryl imines is explored at cobalt（0） center with an imine-N atom as an anchoring group. The reaction of F5C6-CH=N-（2＇-ClC6H4） （2） and FsC6-CH=N-C6H5 （3） wit...In this paper the C--F bond activation of polyfluoroaryl imines is explored at cobalt（0） center with an imine-N atom as an anchoring group. The reaction of F5C6-CH=N-（2＇-ClC6H4） （2） and FsC6-CH=N-C6H5 （3） with Co（PMe3h afforded the C-F bond activation products （ortho-F4C6-CH=N-（2＇-CIC6H4））Co（I）（PMe3）3 （5） and （ortho-F4C6-CH=N-C6Hs）Co（II）（F）（PMe3）2 （6）, while only n-（C=N） coordinated cobalt（0） complex （2,4,5- F3C6H2-CH=N-（4＇-ClC6H4））Co（0）（PMe3）3 （4） was obtained from 2,4,5-F3C6H2-CH=N-（4＇-C1C6H4） （1） without C--F bond activation. Complexes 4--6 were characterized through X-ray single crystal diffraction. It was also found that dialkylation of N-（perfluorobenzylidene）benzenamine with organozinc reagents could be catalyzed by Co（PMe3）4 via C,C-coupling reaction under mild conditions.展开更多
Aiming at the problem of dynamic instability of hard-brittle jointed rock surrounding in deep tunnel/roadway engineering,combining with the support concepts of"coupling rigidity with flexibility"and"ove...Aiming at the problem of dynamic instability of hard-brittle jointed rock surrounding in deep tunnel/roadway engineering,combining with the support concepts of"coupling rigidity with flexibility"and"overcoming rigidity by flexibility",the prevention and control method with"rigid-flexible coupling(R-F-C)"was put forward.Through numerical simulation calculation,the impact damage process,acoustic emission(AE)evolution characteristics,and element stress/displacement evolution characteristics of unsupported surrounding rock structure model,rigid supporting surrounding rock structure model,and"R-F-C"supporting surrounding rock structure model under horizontal bidirectional impact loading were compared and analyzed.Based on the theory of stress wave propagation,the dynamic instability catastrophe mechanism of three kinds of supporting structure models induced by horizontal bidirectional impact loading was revealed.Based on the Mohr-Coulomb strength theory,the stress discrimination methods of dynamic catastrophe of surrounding rock induced by horizontal bidirectional impact loading under three kinds of supporting structures were proposed.Combined with the above numerical simulation study,the explosion impact physical and mechanical test of"R-F-C"surrounding rock supporting plate structure was further designed and carried out.Finally,combined with the"conceptual model of ball-cliff potential energy instability",the energy driving theory and energy transformation mechanism of impact-induced rockburst under three kinds of supporting structures were discussed deeply.The research results provided a scientific basis for further promoting the effective application of"R-F-C"supporting structure in the prevention and control of dynamic instability of deep tunnel/roadway surrounding rock.展开更多
基金Acknowledgement We gratefully acknowledge the support by National Natural Science Foundation of China （No. 21172132）. We also thank the kind assistance from Prof. Dieter Fenske and Dr. Olaf Fuhr （Karlsruhe Nano-Micro Facility, KNMF） for the X-ray diffraction analysis.
文摘In this paper the C--F bond activation of polyfluoroaryl imines is explored at cobalt（0） center with an imine-N atom as an anchoring group. The reaction of F5C6-CH=N-（2＇-ClC6H4） （2） and FsC6-CH=N-C6H5 （3） with Co（PMe3h afforded the C-F bond activation products （ortho-F4C6-CH=N-（2＇-CIC6H4））Co（I）（PMe3）3 （5） and （ortho-F4C6-CH=N-C6Hs）Co（II）（F）（PMe3）2 （6）, while only n-（C=N） coordinated cobalt（0） complex （2,4,5- F3C6H2-CH=N-（4＇-ClC6H4））Co（0）（PMe3）3 （4） was obtained from 2,4,5-F3C6H2-CH=N-（4＇-C1C6H4） （1） without C--F bond activation. Complexes 4--6 were characterized through X-ray single crystal diffraction. It was also found that dialkylation of N-（perfluorobenzylidene）benzenamine with organozinc reagents could be catalyzed by Co（PMe3）4 via C,C-coupling reaction under mild conditions.
基金Project(2023AH051167)supported by the Natural Science Research Project of Anhui Educational Committee,ChinaProject(AHBP2024B-04)supported by the Foundation of Anhui Engineering Research Center of New Explosive Materials and Blasting Technology,China+1 种基金Project(GXZDSYS2023103)supported by the Open Fund for Anhui Key Laboratory of Mining Construction Engineering,ChinaProjects(52274071,52404155)supported by the National Natural Science Foundation of China。
文摘Aiming at the problem of dynamic instability of hard-brittle jointed rock surrounding in deep tunnel/roadway engineering,combining with the support concepts of"coupling rigidity with flexibility"and"overcoming rigidity by flexibility",the prevention and control method with"rigid-flexible coupling(R-F-C)"was put forward.Through numerical simulation calculation,the impact damage process,acoustic emission(AE)evolution characteristics,and element stress/displacement evolution characteristics of unsupported surrounding rock structure model,rigid supporting surrounding rock structure model,and"R-F-C"supporting surrounding rock structure model under horizontal bidirectional impact loading were compared and analyzed.Based on the theory of stress wave propagation,the dynamic instability catastrophe mechanism of three kinds of supporting structure models induced by horizontal bidirectional impact loading was revealed.Based on the Mohr-Coulomb strength theory,the stress discrimination methods of dynamic catastrophe of surrounding rock induced by horizontal bidirectional impact loading under three kinds of supporting structures were proposed.Combined with the above numerical simulation study,the explosion impact physical and mechanical test of"R-F-C"surrounding rock supporting plate structure was further designed and carried out.Finally,combined with the"conceptual model of ball-cliff potential energy instability",the energy driving theory and energy transformation mechanism of impact-induced rockburst under three kinds of supporting structures were discussed deeply.The research results provided a scientific basis for further promoting the effective application of"R-F-C"supporting structure in the prevention and control of dynamic instability of deep tunnel/roadway surrounding rock.
