1. 趙奕姼 Ito Chao Charge-Controlled Hydrogen Bonds in Conjugated Molecules

2. Covalent bond synthesis Covalent bond + Non-covalent bond synthesis Rosette Nanotubes as Conduits H. Fenniri et al, J. Am. Chem. Soc. 2002, 124, 11064 Time

3. Hydrogen bonding changes properties of bound molecules – e.g. sensors UV-visible absorption and luminescence spectra changed upon H-bonding Watanabe, S. et al. J. Am. Chem. Soc. 1998, 120, 229. How about control hydrogen bonding via a remote center?

4. Polarized amide groups enhance binding strength in hydrogen-bonded metallocene complexes Beer, P. D. K Fe 2+ = 4600 M -1 K Fe 3+ = 158000 M -1 K Co 2+ = 2800 M -1 K Co 3+ = 98000 M -1 Tucker, J. H. R. et al. Angew. Chem. Int. Ed. 2000, 39, 3296. More acidic amide proton based on X- ray and IR results * ** * * * * *

5. Implication of charge control in supramolecular chemistry

6. Charge delocalization of the protonated system

7. 4-i nC=C(N) C=C(P) N=N(N) N=N(P) 1 -6.84 -13.17 -7.39 -15.50 2 -6.73 -12.04 -7.66 -16.45 3 -6.64 -11.18 -7.84 -17.99 4 -6.57 -10.47 -7.95 -19.07 Table 1. Ammonia binding energies (kcal/mol) with three-component and two- component systems (4i) calculated at the HF/6-31G* level Chao, I.; Hwang, T.-S. Angew. Chem. Int. Ed. 2001, 40, 2703. H+H+ H3NH3N 4-i -6.22 -7.27 Signal does not die out!

8. Bond length variation in pyrrole-(X=X) n -imine systems

9. 4-i nC=C(N) C=C(P) N=N(N) N=N(P) 1 -6.84 -13.17 -7.39 -15.50 2 -6.73 -12.04 -7.66 -16.45 3 -6.64 -11.18 -7.84 -17.99 4 -6.57 -10.47 -7.95 -19.07 Table 1. Ammonia binding energies (kcal/mol) with three-component and two- component systems (4i) calculated at the HF/6-31G* level Q(pyr) a (0.27) (0.42) (0.22) (0.47) (0.18) (0.59) (0.15) (0.66) a Difference in Mulliken group charge of pyrrole between protonated and neutral three-component systems. Chao, I.; Hwang, T.-S. Angew. Chem. Int. Ed. 2001, 40, 2703. H+H+ H3NH3N 4-i -6.22 -7.27 Signal does not die out!

10. Table 2. Ammonia binding energy (kcal/mol) of protonated three- component systems with (N=N) n bridges calculated with ab initio and DFT methods. n = 1 n=2 n=3 n=4 HF/6-31G*-15.50 -16.45 -17.99 -19.07 HF/6-31+G**-13.41 -14.29 -15.77 -16.78 HF/6-31+G(2d,2p)-12.94 -13.90 -15.36 -16.33 B3LYP/6-31G*-19.19 -19.37 -19.57 -19.79 B3LYP/6-31+G**-16.06-16.26 PW91PW91/6-31G*-21.77-21.88 PW91P86/6-31G*-22.76-22.87 MP2/6-31G*-18.72 -19.27 -20.08 -21.43 MP2/6-31G*//-18.73-19.30-20.07-21.10 B3LYP/6-31G* MP4(SDQ)/6-31G*-17.75 -19.04 MP4(SDQ)/6-31G*// B3LYP/6-31G*-17.42 -18.30 CCSD(T)/6-31G*// MP4(SDQ)/6-31G*-20.30 a -21.04 a a Not corrected for BSSE.

11. Table 3. Ammonia binding energy (kcal/mol) of the protonated three-component system with different -((CH=CH) n -N=N) x - bridges at the HF/6-31G* level. x = 1 x = 2 -(CH=CH-N=N) x --14.63 -15.62 -((CH=CH) 2 -N=N) x --13.90 -14.49 -((CH=CH) 3 -N=N) x --13.19 -13.64 -((CH=CH) 4 -N=N) x --12.61 -12.98 Signal maintenance still possible with more feasible bridges

12. Binding SiteLinkerReaction Center NH 3 …Pyrrol e X=XX=X-N=NN=N-X=XX=X-C=CC=C-X=X C=NH C=NH 2 + C=CC=C-N=NN=N-C=C N=NN=N-C=CC=C-N=N C=NC=N-N=NN=N-C=NC=N-C=CC=C-C=N N=CN=C-N=NN=N-N=CN=C-C=CC=C-N=C C≡CC≡C H+H+ Neutral (N) Protonated (P)

13. Ammonia binding energy of protonated pyrrole-(X=X) n -imine (C=C) n (N=N) n (C=N) n (N=C) n -20 -18 -16 -14 -12 -10 -8 1234 n Binding Energy (kcal/mol) (C ≡ C) n

14. (C=C-N=N) n (C=C-C=N) n (C=C-N=C) n (N=N-C=C) n (C=N-C=C) n (N=C-C=C) n (N=N-C=N) n (N=N-N=C) n (C=N-N=N) n (N=C-N=N) n -20 -18 -16 -14 -12 -10 -8 12 n Binding Energy (kcal/mol) Ammonia binding energy of protonated pyrrole-(X=X-X=X) n -imine

15. Model construction QHQH Q H (whole mol.) EE 

16. Correlation of binding energy and Q H QHQH

17. Q H (a.u.) Correlation of Q H and energy gap between pyrrole HOMO and two-component LUMO QHQH QHQH Through-bond intramolecular charge transfer (ICT)

18. Correlation of binding energy and molecular electrostatic potential (MEP) of the two-component system CH=NH 2 + MEP Q = +1 Through-space electrostatic effect important when ICT is absent

19. Model construction (C=C) n -iminium (N=N) n -iminium 2121 1212 Signal reduction Signal maintaining

20. Bridge effect on two-component LUMO Better bridge: Low-lying  -HOMO and  -LUMO Confirmed by three-component systems containing CF=CF units

21. Table 1. Ammonia binding energies (kcal/mol) with three-component systems at the HF/6-31G* level nC=C(N) C=C(P) CF=CF(N) CF=CF(P) 1 -6.84 -13.17 -7.07 -14.00 2 -6.73 -12.04 -7.27 -13.31 3 -6.64 -11.18 -7.38 -12.82 4 -6.57 -10.47 -7.54 -12.51 Hwang, T.-S. et al. Chem. Eur. J., accepted. CF=CF superior in terms of signal maintenance and signal sensitivity.

22. Ammonia binding energy of protonated pyrrole-(X=X) n -imine (C=C) n (N=N) n (C=N) n (N=C) n -20 -18 -16 -14 -12 -10 -8 1234 n Binding Energy (kcal/mol) (C ≡ C) n Introduction of N lowers  /  * orbital energies, but orientation important.

23. (C=C-N=N) n (C=C-C=N) n (C=C-N=C) n (N=N-C=C) n (C=N-C=C) n (N=C-C=C) n (N=N-C=N) n (N=N-N=C) n (C=N-N=N) n (N=C-N=N) n -20 -18 -16 -14 -12 -10 -8 12 n Binding Energy (kcal/mol) Ammonia binding energy of protonated pyrrole-(X=X-X=X) n -imine Introduction of N lowers  /  * orbital energies, but orientation important.

24. Recent success in employing a remote charge center to affect hydrogen bonding Sessler, J. L. et al. J. Am. Chem. Soc. 2002, 124, 1134. K a (F - ; DMSO) = 440 M -1 K a (F - ; DMSO) = 12000 M -1 K a (F - ; DMSO) = 54000 M -1

25. Conclusion Coupled with experimental evidences, remote control of hydrogen bonds by charge alteration is feasible. A model is established to understand the signal reduction/maintaining phenomenon. A bridge with low-lying  -HOMO and  -LUMO is expected to facilitate the signal amplifying behavior. Orientation of the bridge is important. Limited structure units can be used to construct bridges of very different properties.

26. Acknowledgement 黃聰松 阮寧 陳信允 陳政仲 駱思融 ＄＄＄國科會、中央研究院