Soluble and Stable Near-Infrared Dyes Based on Polycyclic Aromatic Compounds Jiao Chongjun M.Sc., Soochow University A THESIS SUBMITTED FOR THE DEGREE OF PHILOSOPHY DEPARTMENT OF CHEMISTRY NATIONAL UNIVERSITY OF SINGAPORE 2011 ACKNOWLEDGEMENTS This PhD thesis marks the end of a long journey and I would like to take this opportunity to thank all those persons who have given their invaluable assistance for making this journey possible First of all I would like to express my heartfelt gratitude and sincere thanks to my supervisor Dr Wu Jishan for all his scientific guidance, invaluable suggestions and timely encouragement over the past few years Without these my PhD thesis would not have been possible I am fortunate to have such an outstanding supervisor, whose enthusiasm towards scientific research and creative ideas will be kept in my mind throughout my life Second of all I would like to thank Dr Chi Chunyan as well as all the members of Wu and Chi’s group, both past and present, for sharing their knowledge and for their support during group meetings and seminar discussions I had a pleasant and unforgettable time working with them in the lab for the last four years Particular thanks should be given to our collaborators: Dr Huang Kuo-wei who conducted TD-DFT calculations, Prof Wang Peng who constructed and characterized DSC devices, and Prof Xu Qinghua who measured fluorescence lifetimes of my perylene-fused porphyrin NIR dyes I am also grateful to the staff in the department of chemistry for their kind assistance during my PhD career My warmest thanks also go to National University of Singapore (NUS) and Singapore government for providing me with financial support Last but certainly not least, I am profoundly indebted to my parents, Mr Jiao Erzheng and Mrs Tan Zhenyi, and my wife Ms Wang Li who always strongly support me, love me and take pride in me They always stood right next to me during the troubles and toughness at various stages of my PhD work Thesis Declaration The work in this thesis is the original work of Jiao Chongjun, performed independently under supervision of Dr Wu Jishan, (in the laboratory Organic Electronics & Supramolecular Chemistry), Chemistry Department, National University of Singapore, between 2007 and 2011 The content of the thesis has been partly published in: (1) C Jiao, J Wu*, “Fused polycyclic aromatic compounds with near infrared absorption and emmision”, Synlett 2012, 23, 171-184 (2) C Jiao, N Zu, K Huang, P Wang*, J Wu*, “Perylene anhydride fused porphyrins as near-infrared sensitizer for dye-sensitised solar cells”, Org Lett 2011, 13, 3652-3655 (3) C Jiao, L Zhu, J Wu*, “BODIPY-fused porphyrins as soluble and stable near-IR dyes”, Chem Eur J 2011, 17, 6610-6614 (Highlighted by T M Swager et al., Synfacts, 2011, 8, 0851) (4) C Jiao, K Huang, J Wu*, “Perylene-fused BODIPY dye with near-IR absorption/emission and high photostability”, Org Lett 2011, 13, 632-635 (5) C Jiao, K Huang, C Chi, J Wu*, “Doubly and triply fused porphyrinperylene monoimides with large dipole moment and high photostability”, J Org Chem 2011, 76, 661-664 (Highlighted by T M Swager et al., Synfacts, i 2011, 4, 0379) (6) C Jiao, J Wu*, “Nanosized graphenes: chemical synthesis and applications in materials science”, invited book chapter in the book “Graphene: synthesis and applications”, Taylor and Francis Books / CRC Press, 2011, p145-182 (7) C Jiao, K Huang, Z Guan, Q Xu, C Chi, J Wu*, “N-annulated perylene-fused porphyrins with enhanced NIR absorption and emission”, Org Lett 2010, 12, 4046-4049 (8) C Jiao, J Wu*, “New soluble and stable NIR dyes based on polycyclic aromatics”, Curr Org Chem 2010, 14, 2145-2168 (9) C Jiao, K Huang, K Zhang, J Luo, C Chi, J Wu*, “Bis-N-annulated quaterrylenebis(dicarboximide)s as a new soluble and stable NIR dye”, Org Lett 2009, 11, 4508-4511 (Highlighted by T M Swager et al., Synfacts, 2010, 1, 0044) (10) L Zhu,† C Jiao,† D Xia, J Wu*, “N-annulated perylene dyes with adjustable photophysical properties”, Tetrahedron Lett (†equal contribution) 2011, 52, 6411-6414 _ Name _ Signature Date ii TABLE OF CONTENTS Thesis declaration i Table of contents iii Summary vii List of abbreviations ix List of publications xi List of figures xiv List of schemes xvii List of tables xviii Chapter Introduction 1.1 Introduction 1.2 Literature review 1.2.1 Rylene derivatives 1.2.2 Porphyrin-based molecules 13 1.2.3 Phthalocyanine derivatives 19 1.2.4 Summary and outlook 22 1.3 Objectives 22 1.4 References 24 Chapter “Push-pull” N-annulated perylene dyes with 30 adjustable photophysical properties 2.1 Introduction 30 2.2 Results and discussion 32 2.3 Conclusion 40 2.4 Experimental section 40 2.4.1 General 40 2.4.2 Detailed synthetic procedures and characterization data 42 2.5 References 50 Chapter Bis-N-annulated quaterrylenebis(dicarboximide)s as 52 iii soluble and stable NIR dyes 3.1 Introduction 52 3.2 Results and discussion 54 3.3 Conclusion 63 3.4 Experimental section 63 3.4.1 General 63 3.4.2 Detailed synthetic procedures and characterization data 64 3.5 References 73 Chapter Perylene-fused Porphyrins as NIR dyes with tunable 77 absorption/emission 4.1 N-annulated perylene-fused porphyrins with enhanced 77 near-IR absorption and emission 4.1.1 Introduction 77 4.1.2 Results and discussion 79 4.1.3 Conclusion 88 4.1.4 Experimental section 88 4.1.4.1 General 88 4.1.4.2 Detailed synthetic procedures and characterization data 90 4.1.4.3 Transient absorption and pump probe experiments 102 4.2 Doubly and triply fused porphyrin-perylene monoimides 104 with large dipole moment and high photostability 4.2.1 Introduction 104 4.2.2 Results and discussion 106 4.2.3 Conclusion 113 4.2.4 Experimental section 114 4.2.4.1 General 114 4.2.4.2 Detailed synthetic procedures and characterization data 115 4.3 References 119 Chapter Perylene and porphyrin-fused BODIPYs as soluble 124 iv and stable NIR dyes 5.1 Perylene-fused BODIPY dyes with near-IR absorption, 124 emission and high photostability 5.1.1 Introduction 124 5.1.2 Results and discussion 125 5.1.3 Conclusion 135 5.1.4 Experimental section 135 5.1.4.1 General 135 5.1.4.2 Detailed synthetic procedures and characterization data 136 5.2 BODIPY-fused porphyrins as soluble and stable near-IR dyes 147 5.2.1 Introduction 147 5.2.2 Results and discussion 149 5.2.3 Conclusion 157 5.2.4 Experimental section 158 5.2.4.1 General 158 5.2.4.2 Detailed synthetic procedures and characterization data 159 5.3 References 165 Chapter Perylene anhydride-fused porphyrins as NIR 170 sensitizers for dye-sensitized solar cells 6.1 Introduction 170 6.2 Results and discussion 172 6.3 Conclusion 179 6.4 Experimental section 180 6.4.1 General 180 6.4.2 Detailed synthetic procedures and characterization data 181 6.4.3 Device fabrication and characterization 190 6.5 References 192 Chapter Conclusions and future research 196 7.1 Summary of results 196 v 7.2 Future research 199 Appendix NMR spectra of all new compounds and MALDI-TOF 201 spectra of target molecules vi SUMMARY Current developments in the field of electronics and in the area of bioimaging have boosted interest in the development of next-generation functional dyes A recent rising interest is the design and synthesis of so-called near infrared (NIR) dyes which are required for various advanced technologies Many commercially available NIR dyes such as cyanine and polyene dyes suffer from inherent drawbacks due to their insufficient photostability Additionally, some NIR dyes/pigments also suffer from poor solubility for practical applications Thus, the purpose of this thesis was to design and synthesize soluble and stable NIR dyes In this dissertation, polycyclic aromatic compounds (perylene, porphyrin and BODIPY units) have been utilized and two strategies (“push-pull”, core extension) have been adopted to synthesize numerous π-extended molecules with varied physical and optical properties All the new compounds synthesized in this thesis were structurally verified by different spectroscopic methods Throughout the research work, solubility and stability problems have been resolved for theses highly conjugated systems after state-of-art design and modifications The fundamental structure-property relationships were systematically investigated and experimental experiences were accumulated Furthermore, preliminary examination of applications of our NIR dyes was conducted, which may pave the way for a broad range of applications in future Therefore, it is inevitable that more and more soluble and stable NIR dyes based on polycyclic aromatic compounds will be synthesized in our group in the vii MALDI-TOF mass spectra of target molecules Compound 2-1 919.633 3500 3000 Intens [a.u.] 2500 2000 1500 1000 500 600 800 1000 1200 M/Z 1400 1600 1500 1000 922.663 2000 921.629 Intens [a.u.] 2500 920.653 3000 919.633 3500 500 918 920 922 M/Z 924 926 298 Compound 2-2 971.702 1000 Intens [a.u.] 800 600 400 200 600 800 1000 1200 1400 M/Z 1600 1800 2000 400 200 974.721 600 973.714 Intens [a.u.] 800 972.726 971.702 1000 968 970 972 974 976 978 M/Z 299 753.531 Compound 2-3 750 Intens [a.u.] 600 450 300 150 800 750 754.515 600 450 300 755.549 Intens [a.u.] 1000 1200 1400 1600 1800 2000 M/Z 753.531 600 150 752 753 754 755 756 757 M/Z 300 Compound 2-4 805.605 4000 3500 Intens [a.u.] 3000 2500 2000 1500 1000 500 600 800 805.605 4000 1000 1200 1400 1600 1800 2000 M/Z 3500 806.619 2500 2000 1500 807.632 Intens [a.u.] 3000 1000 500 804 805 806 807 M/Z 808 809 810 301 Compound 3-1 302 Compound 3-2 303 Compound 4-1 304 Compound 4-2 305 Compound 4-14 306 Compound 4-15 307 200 1275 1200 1280 1400 1285 1600 600 1290 1295 1299.009 1299.963 1000 1296.978 1297.962 1277.912 1297.962 600 1295.963 400 1277.912 1278.890 Intens [a.u.] 400 1279.867 1276.905 Intens [a.u.] Compound 5-1b 800 [M-F]+ 200 1800 2000 M/Z 800 1300 1305 M/Z 308 300 1470 1200 900 1493.937 1493.960 1494.950 900 600 1495.973 1473.904 1474.887 1475.904 Intens [a.u.] 1493.960 1200 300 [M-F]+ 1200 1480 1474.887 Intens [a.u.] Compound 5-9 900 600 1500 1490 1800 M/Z 1500 M/Z 309 Inten s [a.u.] 1000 1000 1400 3000 2000 1830 1840 1600 M/Z 1850 M/Z 1866.168 1867.201 1868.197 1869.157 1870.191 1200 1847.070 1848.134 1849.089 1850.117 1851.109 1827.996 1829.018 1830.005 [M-2F]+ 1830.005 3000 [M-F]+ 1849.089 1868.197 In ten s [a.u ] Compound 5-10 2000 1800 1860 2000 1870 1880 310 In te n s [a u ] 1200 800 400 900 2 6 800 2 6 In te n s [a u ] 1200 Compound 6-1 800 400 1000 1100 1200 1300 1400 1500 M/Z 1244 1246 1248 1250 1252 1254 1256 1258 1260 M/Z 311 1203 390 Compound 6-2 1500 Intens [a.u.] 1200 900 600 300 600 300 1200 1205 1208 406 900 1207 426 Intens [a.u.] 1200 1205 377 1206 387 1500 800 1000 1200 1400 1600 1800 2000 2200 M/Z 1203 390 1204 369 600 1210 1215 M/Z 312 ... absorption in the 400-450 nm region called Soret band and weak absorption in the 500-700 nm region named Q band, both of which correspond to π–π* transitions The elongation of π-conjugation and loss... triazatruxenes -based two-photon absorption chromophores”, J Org Chem 2011, 76, 780–790 Conferences xii (1) “Novel near- infrared dyes based on ‘p’ chemistry”, 27 June 2011, International Conference on Materials... (Oral presentation) (2) “Novel NIR dyes based on P chemistry”, 15 October 2010, The Second Asian NIR Symposium, China (Oral presentation) (3) “New soluble and stable near infrared dyes? ??, 05 March