Participation of chromophore pairs in photoinduced intramolecular electron transfer for a naphthalimide spermine conjugate

Naphthalimide‐Containing Isomeric Urea Derivatives: Mechanoluminescence and Fluoride Recognition

“…These spectralf eatures were diagnostic of the 1,8-naphthalimide derivatives, and was indicative of monomeric emission. [26] The fluorescences pectra of ND-2U in acetonitrile featured emission bands at l em = 380 and 467 nm, attributed to p-p*a nd urea/1,8-naphthalimide charge-transfer transitions, respectively. [10,26] In comparison, the fluorescences pectra of ND-3U and ND-4U exhibited emission bands centred at l em = 343 and 379 nm, respectively,t hat were reminiscent of 1,8-naphthalimide monomeric emission bands.…”

“…[26] The fluorescences pectra of ND-2U in acetonitrile featured emission bands at l em = 380 and 467 nm, attributed to p-p*a nd urea/1,8-naphthalimide charge-transfer transitions, respectively. [10,26] In comparison, the fluorescences pectra of ND-3U and ND-4U exhibited emission bands centred at l em = 343 and 379 nm, respectively,t hat were reminiscent of 1,8-naphthalimide monomeric emission bands. [26] Single crystals of ND-2U were isolateda sasolvate of N,N-dimethylformamide (DMF),a nd it was found that the solvent molecules werei ntermolecularly hydrogen-bonded to the urea NH groups [N1ÀH1A···O5 0.82(2) ,2 .02(2) , 2.820(2) , 166.4(19)8;N 2 ÀH2A···O5 0.86(2) ,2 .58(2) , 3.216(3) ,1 31.5(18)8].…”

“…[10,26] In comparison, the fluorescences pectra of ND-3U and ND-4U exhibited emission bands centred at l em = 343 and 379 nm, respectively,t hat were reminiscent of 1,8-naphthalimide monomeric emission bands. [26] Single crystals of ND-2U were isolateda sasolvate of N,N-dimethylformamide (DMF),a nd it was found that the solvent molecules werei ntermolecularly hydrogen-bonded to the urea NH groups [N1ÀH1A···O5 0.82(2) ,2 .02(2) , 2.820(2) , 166.4(19)8;N 2 ÀH2A···O5 0.86(2) ,2 .58(2) , 3.216(3) ,1 31.5(18)8]. As shown in Figure 2, [37] the solvent molecule was held in the lattice by ap endant CÀH···O interaction invoking the formamide CH and the benzamide C=O groups [C29ÀH29···O2 0.93 ,2 .33 ,3 .136(3) ,145.38].…”

“…The features observed in the absorptions pectra of ND-2U, ND-3U and ND-4U were characteristico f1 ,8-naphthalimide derivatives and indicated weak interactions with the solventint he ground state. [24,26] Notable differencesw ere observedi nt he fluorescence spectra of ND-2U comparedt oND-3U and ND-4U.A ss hown in Figure 1b,t he fluorescences pectra of ND-2U in dimethyl sulfoxide indicated ap rominent emission at l em = 363 nm (fluores-cence quantum yield F F = 0.12), whereas ND-3U and ND-4U revealed emission bands centred at 343 nm (F F = 0.08) and 364 nm (F F = 0.07). These spectralf eatures were diagnostic of the 1,8-naphthalimide derivatives, and was indicative of monomeric emission.…”

Photoinduced Electron Transfer in Ordered Macromolecular Assemblies. Final report for May 1, 1988 - June 30, 2002

“…The NP-spermine conjugate was also shown to self assemble in the presence of low concentrations of a polyelectrolyte of opposite charge, and photoinduced electron transfer for the resulting electrostatic complexes was also observed (ref 43). A companion study utilized a linkage of a coumarin dye framework with azole units that could be investigated in different states of protonation.…”