7. Symmetry Chirality of a molecule is a symmetry properties Asymmetric :no any symmetry element (C 1 ) Dissymmetric: only axes of rotation (C n and D n )
19. Demonstration of electrochemical Switching of CD signals of ( R )-CBEBPB in 0.1 M Bu4NClO4/DMF. (a) first reduction at -0.5 V for 5 s; (b) recovered tetracation by bubbling slowly nitrogen into the solution; (c) second reduction at -0.7 V for 1 min. Demonstration of electrochemical Switching of CD signals of ( R )-CBEBPB by tin. (a) first reduction by tin bubling nitrogen; (b) recovered tetracation by bubbling slowly air into the solution; Repeat (a) and (b) five times.
20. Near-infrared chiroptical properties ORD caculated from experimental data (a) (b) J.Phys.Chem. A, 2003, 107 , 2524 J.Am.Chem.Soc., 2004, 126 , 7514
24. 1. [ α ] D 23.9 = -224.5 o (4.0 mg/10 mL DMF), Mn:5295 2. [α] D 23.7 = -399 o (4.0 mg/10 mL DMF), Mn:15477, PD:1.42 Polymer Based on Model Compounds
25.
26. 1. [ α ] D 23.9 = -100.0 o (4.0 mg/10 mL DMF), M n :6695 Grafting: 50% 2. [ α ] D 23.9 = -?, Mn:? Grafting: 50%
44. poor resolution of polymer small optical rotation small molecular weight
45. Samples [M 0 ] [M 0 ]/[Cat] T/0C Time/h Solvent Yield/% M n PD [a] D / 0 C DJ-D-13-A 0.1 50 30 1 64 10683 -571 DJ-D-13-B 0.2 200 50 1 84 40522 -1616.5
46. ? A yellow solid product. [α] D 20.7 = -755.5 0 (4 mg/10 mL MeCN) [α] D 20.7 = +743.0 0 (4 mg/10 mL DMF) poor resolution of polymer small optical rotation small molecular weight