3310-62-1Relevant academic research and scientific papers
A photoactivable fluorophore based on thiadiazolidinedione as caging group
Gramlich, Gabriela,Nau, Werner M.
, p. 603 - 605 (1999)
(Matrix presented) Photoactivable ("caged*) fluorescent dyes and probes are crucial for temporally and spatially resolved tracer experiments, e.g., in cell biology or fluid physics. The thiadiazolidinedione 1 represents a new class of caged fluorophore. Upon UV-irradiation it releases in a rapid photoreaction with high quantum yield the azoalkane 2. Longer wavelength excitation of 2 to the singlet excited state results in strong and long-lived fluorescence with maximum intensity at 425 nm. It has been demonstrated that one single uncaging laser pulse suffices for time-resolved or steady-state detection of the fluorescence.
Reactions of Bis(N,N'-bicyclic) Diazenium Dications
Nelsen, Stephen F.,Wang, Yichun
, p. 3082 - 3090 (2007/10/02)
Eleven bis(N,N'-bicyclic) diazenium dications were generated from the corresponding hydrazines by NOPF6 oxidation.Their reactivity depends greatly upon the sizes of the bicyclic rings. (We designate bicyclic ring size using the number of atoms in the two bridges in addition to the dinitrogen bridge all the compound share.) Compounds with rings alkylate acetonitrile at 240 K by opening a Cα-N(+) bond to produce a trialkyldiazenium cation, with ΔG(excit.) for the reaction increasing by at least 5.5 kcal/mol as the second bicyclic ring size increases.Compounds with an unsaturated bridge also alkylate acetonitrile; 22/u22(2+) only cleaves the bridge and reacts faster than 21/22(2+), which only cleaves the bridge.Cα-N(+) cleavage of and larger rings by acetonitrile has not been observed. 21/22(2+) is significantly more acidic than 22/22(2+), but both are β-deprotonated by pyridine to produce aminoaziridinium cations at 240 K.At least mostly the exo ring proton is lost from 21/22(2+).Dications with and bridges deprotonate at the α-carbon instead of the β-carbon, and 22/23(2+) is slightly more kinetically acidic than 21/22(2+). 22/24(2+) is deprotonated rapidly by ether at 235 K.
1-Thia-3,4-diazolidine-2,5-dione Functionality: A Photochemical Synthon for the Azo Group
Squillacote, Michael,Felippis, James De
, p. 3564 - 3571 (2007/10/02)
The 1-thia-3,4-diazolidine-2,5-dione functional group was shown to yield azo compounds upon photolysis.This photoreaction when combined with the known ability of this group to react in a Diels-Alder fashion or as a dinucleophile toward alkylating agents greatly increases the utility of this functionality.The dual reactivity of this group was demonstrated in the synthesis of a number of 3,4-dialkyl-1-thia-3,4-diazolodone-2,5-diones.The photolysis of these compounds produced either thermally stable cyclic azo compounds or the decomposition products of thermally unstable azo compounds.
Tetraalkyl-p-urazines and Their Cation Radicals
Nelsen, Stephen F.,Kim, Yaesil,Neugebauer, Franz A.,Krieger, Claus,Siegel, Rolf,Kaftory, Menahem
, p. 1045 - 1051 (2007/10/02)
X-ray strucures for tetramethyl-p-urazine 1 and its dithia derivative 3 show these compounds to exist in significantly twisted boat structures with nearly planar nitrogens.The X-ray structure of the fused bicyclooctyl derivative cation radical 4.+ is consistent with a delocalized structure having equivalent N-N bonds and planar nitrogens.ESR and ENDOR data are consistent with delocalized cation radicals in solution.Cyclic voltammetry and cation radical optical absorption data are reported.Differences between the solvent dependence of the optical absorption maximum for 4.+ and for a bisalkoxyurea which is known to have the positive charge localized (5.+) are discussed.
Photochemical Deazetation of 2,3-Diazabicyclooct-2-ene: Pseudorotation of the Cyclohexanediyl Biradical
Edmunds, Andrew J. F.,Samuel, Christopher J.
, p. 1267 - 1274 (2007/10/02)
Direct irradiation of cis-anti-2H2>-2,3-diazabicyclooct-2-ene leads to bicyclohexane in which the deuterium is predominantly exo, i.e. with inversion of configuration, to hexadiene in which most, but not all, of the vinylic deuterium is present in the E,Z-isomer, and to cyclohexene lacking vinylic deuterium.Qualitatively similar results were obtained for the sensitised irradiation.The results are discussed in terms of a schema in which cleavage of one C-N bond is followed by conformational changes in a diazenyl biradical, and then in a cyclohexanediyl biradical.
Cyclic and polycyclic diazadioxides as quenchers and radical inhibitors
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, (2008/06/13)
Heterocyclic diazadioxides, having the two nitrogen atoms as annular atoms, are employed as quenchers for molecules in the excited state. The compounds can be used in combination with polymers and pigments for protection against light and oxidative attack. The products are also found to be efficient free radical inhibitors. Heterocyclic mono- and polycyclic diazadioxides are provided. All of the compounds are found to have relatively low triplet energy values.
