New potential antitumoral fluorescent tetracyclic thieno[3,2-b]pyridine derivatives: interaction with DNA and nanosized liposomes

Table 1 Maximum absorption (λ_abs) and emission (λ_em) wavelengths, molar absorption coefficients (ε) and fluorescence quantum yields of compounds 1 and 2 in several solvents

Solvent	λ_abs (nm) (ε/10⁴ M^-1 cm^-1)		λ_em (nm)		Φ_F
	1	2	1	2	1	2
Cyclohexane	398 (0.84); 377 (1.24); 360 (1.27); 305 (0.95); 258 (3.93)	411 sh (0.33); 354 (2.19); 347 (2.37); 308 (1.25); 291 (1.12); 270 (1.40)	402; 426; 452 sh	417; 441	0.20	0.047
Dioxane	398 (0.76); 377 (1.18); 359 (1.20); 305 (1.17); 258 (3.60)	411 sh (0.66); 356 (5.36); 346 (5.40); 309 (3.23); 291 (2.98); 272 (3.33)	407; 428; 455 sh	425; 449	0.29	0.054
Dichloromethane	397 (0.58); 377 (0.91); 360 (0.93); 305 (0.97); 259 (2.70)	410 sh (0.55); 357 (4.37); 311 (2.28); 290 (2.29); 273 (2.78)	408; 429	427; 448	0.26	0.022
Acetonitrile	395 (0.68); 376 (1.06); 358 (1.06); 304 (1.09); 256 (3.32)	409 sh (0.66); 355 (5.76); 308 (3.41); 289 (3.20); 271 (3.67)	408; 428	450	0.21	0.036
N,N-Dimethylformamide^a	397 (0.78); 377 (1.19); 360 (1.16); 305 (1.19)	411 sh (0.69); 356 (5.52); 311 (3.11); 290 (2.86)	411; 430	453	0.30	0.047
Dimethylsulfoxide^a	397 (0.77); 378 (1.17); 361 (1.14); 305 (1.17)	412 sh (0.61); 357 (4.70); 313 (2.52)	413; 432	455	0.28	0.048
Ethanol	396 (0.69); 375 (1.13); 358 (1.17); 304 (1.40); 256 (3.59)	408 sh (0.72); 355 (5.50); 311 (2.95); 272 (3.69)	412; 431	452	0.27	0.041
Methanol	395 (0.67); 374 (1.08); 358 (1.10); 304 (1.34); 256 (3.43)	408 sh (0.62); 354 (5.00); 311 (2.80); 272 (3.41)	413; 433	453	0.26	0.040
Water	394 (0.41); 374 (0.57); 361 (0.58); 303 (0.93); 256 (2.07)	420 sh (0.26); 358 (0.87); 314 (0.94); 278 (0.97)	413 sh; 433	505	0.22	0.012

^aSolvent cut-offs: N,N-Dimethylformamide: 275 nm; Dimethylsulfoxide: 280 nm; sh: shoulder.