"Science, Faculty of"@en . "Chemistry, Department of"@en . "DSpace"@en . "UBCV"@en . "Katagiri, Seiko"@en . "2011-09-27T18:52:59Z"@en . "1964"@en . "Master of Science - MSc"@en . "University of British Columbia"@en . "The fluorescence and absorption spectra of anthracene in the near ultra-violet were investigated in n-heptane, fluorene, biphenyl and n-hexane matrices at low temperature. The assignment of the excited electronic state as \u00E2\u0080\u0098Biu was confirmed. In the ground electronic state eight Qg and five b\u00E2\u0082\u0083g, and in the 'B\u00E1\u00B5\u00A2\u00E1\u00B5\u00A5 upper electronic state seven Qg and five b\u00E2\u0082\u0083g fundamentals were assigned. It was deduced that the potential surfaces of the 'Ag and the 'B\u00E1\u00B5\u00A2\u00E1\u00B5\u00A5 states were similar in shape as there was an approximate agreement between the values of corresponding fundamental vibrations in the two electronic states. The potential surfaces were unusually harmonic for a polyatomic molecule, at least along the normal co-ordinates available to this study. No evidence for the presence of anharmonicity was found in even the highest overtone (the third) measured, although several possible examples of Fermi resonance between vibrational modes were observed both in fluorescence and in absorption. The Fermi resonances were assigned primarily on the basis of intensity transfer between lines rather than line shifts. The presence of a weaker long-axis polarized transition ( 'B\u00E2\u0082\u0082\u00E1\u00B5\u00A5- 'Ag ) in anthracene predicted by theory was not detected. The lowest energy electronic transition in fluorene was found to be polarized along the long axis of this molecule."@en . "https://circle.library.ubc.ca/rest/handle/2429/37650?expand=metadata"@en . "THE ABSORPTION AND FLUORESCENCE OF ANTHRACENE IN THE NEAR ULTRA-VIOLET by SEIKO KATAGLRI B. En., The U n i v e r s i t y of N i i g a t a , Japan, 1962 A THESIS SUBMITTED IN PARTIAL FULFILMENT OF THE REQUIREMENTS FOR THE DEGREE OF M. Sc. i n the Department of Chemistry We accept t h i s t h e s i s as conforming to the required standard THE UNIVERSITY OF BRITISH COLUMBIA A p r i l , 1964 In p r e s e n t i n g t h i s t h e s i s i n p a r t i a l f u l f i l m e n t of the requirements f o r an advanced degree at the U n i v e r s i t y ' o f \u00E2\u0080\u00A2 B r i t i s h Columbia, I agree that the L i b r a r y s h a l l make i t f r e e l y a v a i l a b l e f o r reference and study,, I f u r t h e r agree that per-m i s s i o n f o r extensive copying of t h i s t h e s i s f o r s c h o l a r l y purposes may be granted by the Head of my Department or by h i s r e p r e s e n t a t i v e s . I t i s understood t h a t : c o p y i n g or p u b l i -c a t i o n of t h i s t h e s i s f o r f i n a n c i a l gain s h a l l not be allowed without my w r i t t e n p e r mission. Department of The U n i v e r s i t y of B r i t i s h Columbia, Vancouver 8, Canada v i i ABSTRACT The fluorescence and absorption spectra of anthracene i n the near u l t r a - v i o l e t were i n v e s t i g a t e d i n n-heptane, flu o r e n e , biphenyl and n-hexane matrices at low temperature. The assignment of the e x c i t e d e l e c t r o n i c s t a t e as lBiu was confirmed. In the ground e l e c t r o n i c s t a t e eight Q^and f i v e |>^, and i n the 'B|V upper e l e c t r o n i c s t a t e seven and f i v e b j | fundamentals were assigned. I t was deduced that the p o t e n t i a l surfaces of the ' A | and the '6,u s t a t e s were s i m i l a r i n shape as there was an approximate agreement be-tween the values of corresponding fundamental v i b r a t i o n s i n the two e l e c t r o n i c s t a t e s . The p o t e n t i a l surfaces were un-u s u a l l y harmonic f o r a polyatomic molecule, at l e a s t along the normal co-ordinates a v a i l a b l e t o t h i s study. No evidence f o r the presence of anharmonicity was found i n even the highest overtone (the t h i r d ) measured, although s e v e r a l p o s s i b l e examples of Fermi resonance between v i b r a t i o n a l modes were observed both i n fluorescence and i n absorption. The Fermi resonances were assigned p r i m a r i l y on the basis of i n t e n s i t y t r a n s f e r between l i n e s r a t h e r than l i n e s h i f t s . . The presence of a weaker long-axis p o l a r i z e d t r a n s i t i o n ( 'B^u*- '/^ ) i n anthracene p r e d i c t e d by theory was not detected. v i i i The lowest energy e l e c t r o n i c t r a n s i t i o n i n fluorene was found to be p o l a r i z e d along the long a x i s of t h i s molecule. \ ACKNOWLEDGMENT I am deeply g r a t e f u l to Dr. Alan V. Bree f o r h i s guidance and encouragement i n every phase of t h i s work; h i s assistance has developed my i n t e r e s t and understanding i n the work. I wish t o express my a p p r e c i a t i o n to Miss V.V.B. V i l k o s f o r her help i n many ways, and a l s o to the te c h n i c i a n s i n t h i s department f o r the preparation of some equipment. i i i CONTENTS Page SURVEY OF PREVIOUS WORK 1 T h e o r e t i c a l P r e d i c t i o n s 1 E l e c t r o n i c States of Anthracene 1 V i b r a t i o n a l States of Anthracene 3 Mixed C r y s t a l Phenomena 5 Previous \"Experimental Work 6 EXPERIMENTAL ARRANGEMENT 8 Preparation of the Samples . . 8 Measurement of the Spectra 10 Apparatus 10 Measurement of the Lines 11 RESULTS 14 DISCUSSION 31 Fluorescence Spectra 31 Fundamental Modes . . . 31 Fermi Resonance 3# Other Features 3\u00C2\u00A7 Absorption Spectra 38 Fundamental Modes of the ' B t u u P P e r State 38 Comparison of the Fundamentals on the ' A|and on the E l e c t r o n i c States \u00E2\u0080\u00A2 3\u00C2\u00A7 i v Page Fermi Resonance . 41 Other Lines . . . . . . . . . 43 S h i f t of the Origins of tke 'B.^'A, T r a n s i t i o n i n the D i f f e r e n t Matrices . 49 BIBLIOGRAPHY 50 V TABLES Table Page 1 Character Table of P*h and the Axis Convention of the Anthracene Molecule : 2 2 A Summary of Some C a l c u l a t i o n s on the E l e c t r o n i c States, of Anthracene i n the Near E l t r a - V i o l e t . 2 3 0^ and t>>^ Fundamentals Observed i n Anthracene . 7 4 Fluorescence Spectra of Anthracene i n Various Matrices 17 5 Absorption Spectra of Anthracene i n Various Matrices . 24 6 Absorption Spectrum of Fluorene at 4.2\u00C2\u00B0K 31 7 P o s s i b l e Examples of Fermi Resonance i n the Fluorescence of Anthracene 34 8 The Fundamentals of Anthracene i n the Ground and the ' Upper State 40 9 P o s s i b l e Examples of Fermi Resonance i n the Absorption of Anthracene 41 10 S i m i l a r i t y of the Stru c t u r e around Some Strong Absorption Lines 44 v i FIGURES Figure Page 1 Low Temperature Sample C e l l s 12 2 The Fluorescence Spectrum of Anthracene i n n-Heptane at 4.20K 15 3 The Fluorescence Spectrum of Anthracene i n Fluorene at 4.2\u00C2\u00B0K 15 4 R e l a t i v e I n t e n s i t i e s of the Lines i n F l u o r e s -cence (a) Anthracene i n n-Heptane at 4.2\u00C2\u00B0K (b) Anthracene i n Fluorene at 4.2\u00C2\u00B0K . . . . 16 5 Absorption Spectrum of Anthracene In n-Heptane at 4.20K fZky 6 Absorption Spectrum of Anthracene i n Fluorene at 4.2\u00C2\u00B0K .vi ''.'2\u00C2\u00A3. 7 R e l a t i v e I n t e n s i t i e s of the Lines i n Absorption (a) Anthracene i n n-Heptane at 4.2\u00C2\u00B0K (b) Anthracene i n Fluorene at 4.2\u00C2\u00B0K . . . . SURVEY OP PREVIOUS WORK Th e o r e t i c a l P r e d i c t i o n s E l e c t r o n i c States of Anthracene Group theory may be u s e f u l l y applied to the c a l c u l a -t i o n of the molecular o r b i t a l s (MO's) of an anthracene molecule us i n g as a basis set the atomic 2p* f u n c t i o n s centred on each carbon nucleus. Anthracene possesses PaW molecular symmetry and i t s character t a b l e and a x i s convention are shown below. I t can be shown (1) that the one-electron MO's are /\o, B I J , B a j and &30 y i e l d i n g the c o n f i g u r a t i o n s A9, Bi U \u00C2\u00BB B\u00C2\u00BBu and B a * . According to Weissman (2) antisymmetric s p i n func-t i o n s have symmetry, so s i n g l e t T T - e l e c t r o n c o n f i g u r a t i o n s r e t a i n the symmetry given above. Thus the only allowed t r a n s i t i o n s a r i s i n g from the ground s t a t e are to & i 0 and fc8Uexcited s t a t e s p o l a r i z e d along the long and short a x i s of the molecule, r e s p e c t i v e l y . Many c a l c u l a t i o n s ( 3 ) - ( l 3 ) have been c a r r i e d out on the energies of the e l e c t r o n i c t r a n s i t i o n s of anthracene and the corresponding o s c i l l a t o r strengths ( f ) i n d i f f e r e n t approximations (e.g. a l l o w i n g f o r the i n t e r a c t i o n between many c o n f i g u r a t i o n s , the i n c l u s i o n of many-centred i n t e g r a l s 2 Table 1 Character Table of D2h and the Axis Convention of the Anthracene Molecule * V * yt xx xy D2h E C2 C2 C2 i rj f tf\" T R z(M> Ag 1 1 1 1 Au 1 1 1 1 B i g 1 - 1 - 1 1 B l u 1 -1 -1 1 B2g 1-1 1 - 1 B2u 1-1 1 - 1 B3g 1 1 - 1 - 1 B3u 1 1 - 1 - 1 i n the s e c u l a r equation, e t c . ) . A l l c a l c u l a t i o n s put only Diu and ' B w l e v e l s i n the region of the 3800 A system. Only one c a l c u l a t i o n (9) found the ' B I U l e v e l lower than 'feto* T t l e o s c i l l a t o r s trength of the Vljf t r a n s i t i o n was much higher than that of the '^ iy - - ' / , } i n every approximation, and f o r the l a t t e r P a r i s e r (8) and Mataga (10) ca l c u l a t e d zero. Table 2 A Summary of Some C a l c u l a t i o n s on the E l e c t r o n i c States of Anthracene i n the Near U l t r a - V i o l e t 1 1 1 1 1 -1 -1 -1 1 -1 -1 1 Rz 1 1 1 -1 Tz 1 -1 \u00E2\u0080\u00A2 1 -1 Ry 1 1 -1 1 Ty 1 1 -1 -1 Rx 1 -1 1 1 Tx r e f . \u00E2\u0080\u00A2 Blu (HI) f 'B lut f lO V.B. 3 3.07 M.O. 4 0.836 Jr 1.261 Jr X =resonance integral 5 0.11 0.005 Modified 6,7 3-72 (\u00C2\u00A3,a) (c) 161 3227 389+590+744+1503+1 162 3248 3254 3258 3264 389+1399+1464+12 163 3283 3277 3280 3288 3292 3293 389+1399+1503+2 164 3333 3339 3340 3342 3345 3348 2x389+1164+1399+7? 165 3365 3389 3384 590+2x1399-4 166 3394 389+2x1503-1 167 3416 3414 744+1157+1503+7 168 3433 3443 3446 3439 3442 2x389+1157+1503+4 169 3476 3460 1399+2x1030+1 170 3565 3569 3564 3573 3580 3574 2x389+2x1399-3 171 3588 1030+1157+1399+2 172 3602 3609 590+2x1503+13 173 3634 e 174 3668 3654 3648 744+1399+1503+2 175 3666 3678 3688 3678 2x398+1399+1503 176 3718 3718 3714 1399+2x1157+1 177 3750 3723 3737 3731 3x389+1157+1399+8 178 3813 3804 3823 3823 3826 1030+2x1399-2; 1503+2x1157+9? 179 3838 3858 3857 3853 389+663+2x1399+3? 180 3886 1030+1399+1464-7? 181 3903 1157+1247+1503-4? 894+2x1503+3? 182 3922 1030+1399+1503-10; 389+744+2x1399-9? 183 3955 3944 3948 3968 3955 1157+2x1399 184 3985 389+1030+1166+1399+1; 389+1030+1157+1399+10 185 4013 4017 1157+1399+1464-3 186 4035 4030 1030+2x1503-6 187 4042 4066 4058 4073 4055 1157+1399+1503-4 188 4097 4112 4100 389+1399+2x1157-2 189 4108 4117 4118 4134 4118 1157+1464+1503-6 190 4149 4160 1157+2x1503-1 191 4177 4180 4172 4197 4199 4195 3x1399-2 192 4198 4214 389+1030+2x1399-3; 389+2x1157+1503+8 193 4227 663+2x389+2x1399-12? 194 4225 4262 4261 4265 1464+2x1399+3 195 4280 4278 4280 4294 4301 4297 1503+2x1399-4 196 4328 4339 4327 4349 4352 4351 389+1157+2x1399-7 197 4368 392+1166+2x1396+18 198 4388 4380 1399+1464+1503+14 Table 5 continued 29 biphenyl n- fluorene, n-heptane a. 4 . 2 0 K hexane 4 . 2 0 K 11M 111 77\u00C2\u00B0K 11M 111 77\u00C2\u00B0K 63\u00C2\u00B0K 4 . 2 0 K remarks (b) (c) (b,a) (c) 199 4433 4438 4447 4446 389+1157+1399+1503+2; 389+1166+1399+1503-7? 200 4515 4513 4509 3x1503 201 4552 4545 389+1157+2x1503-7 202 4572 4582 4585 4589 4584 389+3x1399-2 203 4630 4630 4699 4656 4655 389+1464+2x1399+4 204 4668 4667 4684 4691 4683 389+1503+2x1399-7 205 4723 4700 4739 4741 4739 2x389+1157+2x1399+6; 2x389+1166+2x1399-3 206 4829 4832 2x389+1157+1399+1503-5 207 4890 389+3x1503-8; 590+1503+2x1399-1 208 4973 2x389+3x1399-2 209 5047 2x389+1464+2x1399+7; 744+1503+2x1399+2 210 5076 2x389+1503+2x1399-3 211 5126 2x1157+2x1399+14?; 1157+1166+2x1399+5 212 5227 1030+3x1399; 1030+1503+2x1399-4; 1399+1503+2x1157+11? 1157+1166+1399+1503+2^ 213 5366 1157+3x1399+12; 1166+3x1399+3 214 5417 1157+1464+2x1399-2; 215 5437 1247+3x1399+7? 216 5458 1157+1503+2x1399 217 5522 1157+1399+1464+1503-1 218 5567 1464+3x1399+6; 1157+1399+2x1503+5? 219 5596 4x1399 220 5672 1157+3x1503+6; 1464+3x1399+11 221 5684 1503+3x1399-16 222 5741 389+1157+3x1399-2; 389+1166+3x1399-11? 223 5825 389+1166+1464+2x1399+8 389+1157+1464+2x1399+ 17 224 5846 389+1157+1503+2x1399-1 225 5910 1399+3x1503+2 226 5983 389+4x1399-3 227 6053 389+3x1399+1464+3 30 Table 5 continued biphenyl n- flu o r e n e , n-heptane ( a 4 . 2 \u00C2\u00B0K hexane 4.2 OK im 111 77\u00C2\u00B0K 11M 11L 77\u00C2\u00B0K 63\u00C2\u00B0K 4.20K remarks ( b f (c) (b,a) (c) 228 6084 389+1503+3x1399-5 229 6135 2x389+1157+3x1399+3; 2x389+1166+3x1399-6 a. C r y s t a l axes are shown i n brackets while M and L show molecular short and long axes, r e s p e c t i v e l y . b. Assignments are made using the data from the n-heptane spectrum. c. The o r i g i n s i n the d i f f e r e n t matrices are given i n cm-\"1\", and a l l the other e n t r i e s i n the t a b l e show d i f f e r e n c e s from the o r i g i n . d. (FR) Fermi resonance. e. This l i n e i s d o u b t f u l . 31 Table 6 Absorption Spectrum of Fluorene at 4.2\u00C2\u00B0K 11M ( b ) b * 11L (c) 11M (b) 111 (c) 11M (b) 111 {'o) 1 31062 35 31665 69 32219 2 31080 36 31666 31668 70 32230 3 31130 37 31695 31696 71 32246 4 31141 38 31716 72 32254 5 31157 39 31738 73 32262 6 31182 40 31742 74 32274 7 31190 41 31750 75 32298 8 31211 42 31795 76 32319 9 31230 43 31809 77 32323 10 31256 31255 44 31813 78 32359 11 31264 45 31835 79 32367 12 31290 31290 46 31844 80 32381 13 31299 47 31857 31857 81 32385 14 31318 31319 48 3186 3 31860 82 32394 15 31350 49 31892 83 32398 16 31363 50 31902 84 ' 32420 117 31377 31379 51 31919 85 32433 18 31409 31410 52 31928 86 32455 32455 19 31417 53 31956 87 32481 32480 20 31439 54 31959 31961 88 32494 21 31473 55 31967 89 32502 22 31478 56 31984 90 32526 123 31499 57 31992 91 32543 24 31512 58 32005 .32001 92 32569 25 31517 59 32017 93 32590 26 31520 60 32049 94 32603 27 31524 31524 61 32066 95 32619 28 31550 31548 62 32086 32082 96 32644 29 31584 63 32109 32110 97 32672 30 31651 64 32130 98 32687 31 31619 65 32148 99 32706 32 31623 66 32154 100 32731 33 31636 67 32161 101 32752 32755 34 31656 68 32206 32203 102 32761 103 32766 105 32805 107 32829 104 32787 106 32815 108 32858 a. The frequency of each l i n e i s given - 1 i n cm b. C r y s t a l axes are shown i n brackets while M and L show molecular short and long axes, r e s p e c t i v e l y . DISCUSSION Fluorescence Spectra Fundamental Modes S p e c t r a l l i n e s i n fluorescence may a r i s e from anthra-cene molecules, molecules of the matrix or some other im-p u r i t y molecule. Unknown i m p u r i t i e s present a r e a l problem i n fluorescence spectroscopy since a very small t r a c e of impurity (as low as 10 M) can make a l a r g e c o n t r i b u t i o n to the o v e r a l l emission... Lines due to fundamental modes of anthracene may be d i s t i n g u i s h e d from other emission l i n e s since only these form combinations b u i l t on the o r i g i n and the o r i g i n can be a s s i g n -ed from the absorption spectrum. On the basis of t h e i r i n t e n s i t i e s , p o l a r i z a t i o n and a b i l i t y to form combinations eight 0^ fundamental modes of the e l e c t r o n i c s t a t e were assigned: 394, 629, 759, 1020, 1163, 1267, 1409 and 1568 cm\"1. T h e o r e t i c a l l y twelve fundamentals are pre d i c t e d f o r anthracene and among them three due to C-H str e t c h e s appear i n the region of 2900 - 3100 cm - 1 (39). So below 2000 cm\" 1 nine (i^ modes should be found. From t h e i r i n t e n s i t y and p o l a r i z a t i o n behaviour e i t h e r 510, 874 or 1340 cm-1 may be se l e c t e d as t h i s n i n t h fl| fundamental. Among these 510 and 1340 cm - 1 modes appeared one and four times r e s p e c t i v e l y i n combination w i t h known A3 modes while 874 cm d i d not appear at a l l . From t h i s point of view, the n i n t h fundamental i s most probably the l i n e at 1340 cm - 1 w i t h the l i n e at 510 cm\"\"'\" pre f e r r e d next. However, 1340 cm\"1 d i d not appear i n biphenyl while the other two d i d . Further, Raman data (31) shows 522 cm - 1 as ag i n anthracene c r y s t a l and i n s o l u t i o n which i s probably close enough to our 510 cm\"1. No l i n e s corresponding to the other two v i b r a t i o n s were found i n the Raman. Thus although no d e f i n i t e assignment could be made f o r the n i n t h \u00C2\u00A3)g fundamental, the l i n e at 510 cm\"1 seems to be the most probable contender i f emphasis i s placed on i t s appearance i n the Raman spectra. The other two must be i n t e r p r e t e d as impurity l i n e s , or b j | belonging to the e l e c t r o n i c s t a t e i f f o r some reason fluorescence appears from a 1 o r i g i n . 3090 cm\"1 may be assigned as an fundamental due to C-H s t r e t c h i n g since i t does not analyse as a combination l i n e , i t agrees w i t h previous e m p i r i c a l data (39) and i t has the expected p o l a r i z a t i o n . However, 3526 cm - 1 i s probably too high to be assigned as an a