The tensile cable-strut structure is a self-equilibrate pre-stressed system.The initial pre-stress cal- culation is the fundamental structural analysis.A new numerical procedure was developed.The force density method ...The tensile cable-strut structure is a self-equilibrate pre-stressed system.The initial pre-stress cal- culation is the fundamental structural analysis.A new numerical procedure was developed.The force density method is the cornerstone of analytical formula,and then introduced into linear adjustment theory;the least square least norm solution,the optimized initial pre-stress,is yielded.The initial pre-stress and structural performances of a particular single-layer saddle-shaped cable-net structure were analyzed with the developed method,which is proved to be efficient and correct.The modal analyses were performed with respect to various pre-stress levels.Finally,the structural performances were investigated comprehensively.展开更多
Crystal structure of the title compound, macrocyclic tetrabenzo(b ,f,J, n ) [ 1, 5, 9, 1 3] tetraazacyclohexadecine (TAAB ) N, N'-dimethyl formamide(DMF) ruthenium (Ⅱ) complex, [Ru (taab) (DMF )_2]·[ (ClO_4 ...Crystal structure of the title compound, macrocyclic tetrabenzo(b ,f,J, n ) [ 1, 5, 9, 1 3] tetraazacyclohexadecine (TAAB ) N, N'-dimethyl formamide(DMF) ruthenium (Ⅱ) complex, [Ru (taab) (DMF )_2]·[ (ClO_4 )_2](C_(34) H_(34)Cl)2N_6O_(10)Ru , M_r= 874. 66) is monoclinic with space group C2/c and a =36. 689(2) , b=18. 173 (8 ),. c= 10. 666(3)A, β=102. 6(4)°, V=6939. 6 A￣3 , D_c= 1. 67 gcm￣(-3), Z=8. The structural solutions and refinements based on 3183 reflections (I≥3σ(I)) converged at R= 0. 071 , R_w = 0. 074. The TAAB macrocyclic ligand has a saddle-shaped appearance,the ruthenium(Ⅱ) is located on the plane of the four nitrogen atoms of the TAAB with the two perpendicular Ru(Ⅱ)-O bonds coordinated to the DMF molecules.展开更多
Dibenzo[b,fi[1,5]diazocines are a class of eight-membered heterocycles,which exhibit unique rigid saddle-shaped structure and possess inherent chirality.In this study,we report a convenient and straightforward method ...Dibenzo[b,fi[1,5]diazocines are a class of eight-membered heterocycles,which exhibit unique rigid saddle-shaped structure and possess inherent chirality.In this study,we report a convenient and straightforward method for the catalytic enantioselective synthesis of these unique chiral molecules through chiral phosphoric acid-catalyzed dimerization of 2-acylbenzoisocyanates.Notably,the addition of corresponding 2-acylaniline as the co-catalyst significantly improved the efficiency of these reactions,and a simple phase separation operation resulted in products with excellent enantiopurity.Experimental studies were performed to elucidate the mechanism behind these reactions,leading to the proposal of a plausible reaction mechanism based on the study findings.展开更多
文摘The tensile cable-strut structure is a self-equilibrate pre-stressed system.The initial pre-stress cal- culation is the fundamental structural analysis.A new numerical procedure was developed.The force density method is the cornerstone of analytical formula,and then introduced into linear adjustment theory;the least square least norm solution,the optimized initial pre-stress,is yielded.The initial pre-stress and structural performances of a particular single-layer saddle-shaped cable-net structure were analyzed with the developed method,which is proved to be efficient and correct.The modal analyses were performed with respect to various pre-stress levels.Finally,the structural performances were investigated comprehensively.
文摘Crystal structure of the title compound, macrocyclic tetrabenzo(b ,f,J, n ) [ 1, 5, 9, 1 3] tetraazacyclohexadecine (TAAB ) N, N'-dimethyl formamide(DMF) ruthenium (Ⅱ) complex, [Ru (taab) (DMF )_2]·[ (ClO_4 )_2](C_(34) H_(34)Cl)2N_6O_(10)Ru , M_r= 874. 66) is monoclinic with space group C2/c and a =36. 689(2) , b=18. 173 (8 ),. c= 10. 666(3)A, β=102. 6(4)°, V=6939. 6 A￣3 , D_c= 1. 67 gcm￣(-3), Z=8. The structural solutions and refinements based on 3183 reflections (I≥3σ(I)) converged at R= 0. 071 , R_w = 0. 074. The TAAB macrocyclic ligand has a saddle-shaped appearance,the ruthenium(Ⅱ) is located on the plane of the four nitrogen atoms of the TAAB with the two perpendicular Ru(Ⅱ)-O bonds coordinated to the DMF molecules.
基金The authors gratefully acknowledge NSFC(grant nos.22222107,22171186)China Postdoctoral Science Foundation(2023M742365)+2 种基金Postdoctoral Fellowship Program of CPSF(GZC20231671)ShanghaiTech University start-up funding for financial support.Prof.Guangxin Liang was acknowledged for sharing the optical rotation polarimeter,and Mr.Huanchao Gu was acknowledged for the assistance with X-ray crystallographic analysissupport from Analytical Instrumentation Center(#SPST-AIC10112914),SPST,ShanghaiTech University.
文摘Dibenzo[b,fi[1,5]diazocines are a class of eight-membered heterocycles,which exhibit unique rigid saddle-shaped structure and possess inherent chirality.In this study,we report a convenient and straightforward method for the catalytic enantioselective synthesis of these unique chiral molecules through chiral phosphoric acid-catalyzed dimerization of 2-acylbenzoisocyanates.Notably,the addition of corresponding 2-acylaniline as the co-catalyst significantly improved the efficiency of these reactions,and a simple phase separation operation resulted in products with excellent enantiopurity.Experimental studies were performed to elucidate the mechanism behind these reactions,leading to the proposal of a plausible reaction mechanism based on the study findings.
