Table 3.

Fluorescence excitation and UV spectra (cm⁻¹) of BCB selected bands.

FES1		UV1		Assignment	Inferred2	Calculated3
		−276	ms	${21}_1^1{42}_1^1$	−172 – 105 = −277
		−262	ms	${22}_1^1{42}_2^2$	−54 – 204 = −258
		−209	ms	${22}_2^0{42}_0^2$	−417 + 209 = −208
		−183	ms	${20}_0^1{22}_3^0$	440 – 624 = −184
		−172	ms	${21}_1^1$	314 – 486 = −172
		−154	s	${22}_1^1{42}_1^1$	−54 – 105 = −159
		−144	s	${41}_1^1$	245 – 386 = −141
		−114	ms	${22}_2^2$	301 – 417 = −116
		−105	s	${42}_1^1$	105 – 209 = −104
		−86	m	${40}_1^1{42}_1^1$	20 – 105 = −85
		−76	s	${14}_1^1$	464 – 539 = −75
		−71	mw	${34}_1^1$	564 – 634 = −70
		−54	mw	${22}_1^1$	153 – 208 = −55
		−48	mw	${20}_0^1{21}_1^0$	440 – 486 = −46
		−38	s	${35}_1^1$	366 – 404 = −38
		−28	mw	${35}_1^1{42}_2^4$	−38 + 8 = −30
		−18	mw	${18}_0^1{20}_1^0$	656 – 670 = −14
0	vs	0	vs	$0_0^0$
		8	mw	${42}_2^4$	420 – 411 = 9
		20	w	${40}_1^1$	737 – 715 = 22
		63	mw	${19}_0^1{21}_1^0$	549 – 486 = 63
		105	ms	${42}_1^3$	209 – 105 = 104
				${21}_0^1{22}_1^0$	314 – 208 = 106
209	ms	209	ms	${42}_0^2$		2 × 109 = 218
301	w	301	w	${22}_0^2$		2 × 157 = 314
420	vw	420	mw	${42}_0^4$	2 × 209 = 418
463	mw	464	vw	${14}_0^1$		465
466	mw	467	m	${21}_0^1{22}_0^1$	314 + 153 = 467
485	m	484	mw	${41}_0^2$		2 × 250 = 500
626	vw	626	mw	${21}_0^2$		2 × 312 = 624
733	ms	731	mw	${35}_0^2$		2 × 375 = 750
				${27}_0^1{34}_1^0$	1364 – 634 = 730
740	s	740	s	${13}_0^1$		713
875	m	875	mw	${20}_0^2$		2 × 450 = 900
893	ms	892	w	${11}_0^1$		843
900	s	900	s	${12}_0^1$		868
940	mw	940	vw	${35}_0^2{42}_0^2$	731 + 209 = 940
949	w	949	w	${14}_0^1{41}_0^2$	464 + 485 = 949
				${13}_0^1{42}_0^2$	740 + 209 = 949
977	vw	978	w	${40}_0^1{41}_0^1$	737 + 245 = 982
986	vvw	987	w	${39}_0^2$		2 × 483
1094	m	1094	ms	${19}_0^2$		2 × 502 = 1004
1113	mw	1113	m	${10}_0^1$		1112
1130	m	1129	w	${34}_0^2$		2 × 567 = 1134
1133	ms	1133	m	${38}_0^2$		2 × 568 = 1136
1169	w	1167	m	$8_0^1$		1170
1208	s	1208	s	$9_0^1$		1209
		1246	vw	${21}_0^4$	2 × 626 = 1252
1313	mw	1313	w	${18}_0^2$		2 × 635 = 1270
1343	mw	1342	vw	${38}_0^2{42}_0^2$	1133 + 209 = 1342
		1363	mw	${12}_0^1{14}_0^1$	900 + 464 = 1364
1370	m	1370	mw	$7_0^1$		1360
1404	mw	1402	w	$6_0^1$		1454
1457	w	1458	vw	${35}_0^4$	2 × 731 = 1462
1470	w	1471	w	${40}_0^2$		2 × 747 = 1494
				${13}_0^1{35}_0^2$	740 + 731 = 1471
1477	s	1477	ms	${13}_0^2$	2 × 740 = 1480
1493	mw	1491	w	$5_0^1$		1484
1517	m	1517	w	${11}_0^1{21}_0^2$	892 + 626 = 1518
1593	vw	1594	vvw	${14}_0^1{34}_0^2$	464 + 1129 = 1593
1597	w	1599	vvw	${14}_0^1{38}_0^2$	464 + 1133 = 1597
1623	mw	1623	mw	${11}_0^1{35}_0^2$	892 + 731 = 1623
		1629	vw	${11}_0^1{13}_0^1$	892 + 740 = 1632
				$8_0^1{14}_0^1$	1167 + 464 = 1631
1633	w	1633	w	${33}_0^2$		2 × 825 = 1650
1640	w	1639	vw	${12}_0^1{13}_0^1$	900 + 740 = 1640
1644	s	1643	s	$4_0^1$		1679
1646	w	1646	mw	${32}_0^1{34}_0^1$	1085 + 564 = 1649
		1765	w	${11}_0^1{20}_0^2$	892 + 875 = 1767
		1785	w	${11}_0^2$	2 × 892 = 1784
		1793	m	${11}_0^1{12}_0^1$	892 + 900 = 1792
		1810	mw	${10}_0^1{42}_2^0$	2222 – 411 = 1811
		1833	mw	$7_0^1{14}_0^1$	1370 + 464 = 1834
				${13}_0^1{19}_0^2$	740 +1094 = 1834
		1871	m	${13}_0^1{38}_0^2$	740 + 1133 = 1873
		1904	w	${32}_0^1{33}_0^1$	1085 + 819 = 1904
		1910	vw	$8_0^1{13}_0^1$	1167 + 740 = 1907
		1931	w	${17}_0^2$		2 × 962 = 1924
		1943	m	${31}_0^2$		2 × 972 = 1944
		1946	m	$9_0^1{13}_0^1$	1208 + 740 = 1948
		1957	vvw	$5_0^1{14}_0^1$	1491 + 464 = 1955
		2003	w	${10}_0^1{11}_0^1$	1113 + 892 = 2005
		2015	vw	${10}_0^1{12}_0^1$	1113 + 900 = 2013
		2031	mw	${35}_1^1{37}_0^2$	−38 + 2069 = 2031
		2041	m	${10}_0^1{14}_0^2$	1113 + 927 = 2040
		2053	vw	${31}_0^1{32}_0^1$	972 + 1085 = 2057
				${13}_0^1{18}_0^2$	740 + 1313 = 2053
		2069	vw	${37}_0^2$		2 × 1038 = 2076
		2092	vvw	$4_0^1{14}_0^1$	1633 + 464 = 2097
		2105	mw	$7_0^1{13}_0^1$	1370 + 740 = 2110
		2116	m	${10}_0^2{42}_1^1$	2222 – 105 = 2117
		2153	vvw	$8_0^1{39}_0^2$	1167 + 987 = 2154
		2222	vw	${10}_0^2$	2 × 1113 = 2226
				$5_0^1{35}_0^2$	1491 + 731 = 2222
		2239	w	${14}_0^2{18}_0^2$	927 + 1313 = 2240
				${10}_0^1{34}_0^2$	1113 + 1129 = 2242
		2256	vw	${34}_0^4$	2 × 1129 = 2258
		2300	vvw	${16}_0^2$		2 × 1169 = 2338
		2376	vw	${30}_0^2$		2 × 1174 = 2378
		2384	w	$4_0^1{13}_0^1$	1643 + 740 = 2383
		2411	vvw	${14}_0^1{31}_0^2$	464 + 1943 = 2407
		2521	vvw	${29}_0^2$		2 × 1261 = 2522
		2531	w	$6_0^1{34}_0^2$	1402 + 1129 = 2531
		2605	vvw	${13}_0^2{34}_0^2$	1477 + 1129 = 2606
		2606	vvw	${13}_0^2{38}_0^2$	1477 + 1133 = 2610
		2679	vw	${13}_0^1{31}_0^2$	740 + 1943 = 2683
		2725	vw	${27}_0^2$		2 × 1366 = 2732
		2845	w	$3_0^1$		2876
		2851	w	${28}_0^2$		2 × 1438 = 2876
		2999	w	${26}_0^2$		2 × 1502 = 3004
		3015	vvw	$2_0^1$		3024
		3068	vvw	$1_0^1$		3045

¹Relative to $0_0^0$ band at 37 093.6 cm⁻¹; the relative intensities are indicated s-stong, m-medium, w-weak, v-very.

²Inferred from other spectroscopic transitions (FES, IR, Raman, and ultraviolet).

³CASSCF(6,6)/aug-cc-pVTZ calculations. Scaling factor: 0.905.