- 9-Anthroylacetone and its photodimer
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9-Anthroylacetone undergoes a head-to-tail [4π+4π] photo-dimerisation reaction that leads to the formation of 5,11-bis(1,3-diketobutyl)-5,6,11,12- tetrahydro-5,12,6,11-di-o-benzeno-dibenzo[a,e]cyclooctene both in solution and in the solid state when irradiated with different sources (sunlight, tungsten lamp, xenon lamp, UV laser beam 351-364 nm), the reaction being accompanied by a colour variation from bright yellow to colourless. Quantum yields >0.023 mol/Einstein are evaluated for the solid state reaction. Interestingly, the dimer dissociates to give 9-anthroylacetone, both thermally (T>130°C) and photochemically, by short UV wavelength irradiation. The single-crystal X-ray structure of 9-anthroylacetone and its dimer are reported. 9-Anthroylacetone undergoes a head-to-tail [4π+4π] photo-dimerisation reaction both in solution and in the solid state when irradiated with different sources; the dimer reversibly dissociates into 9-anthroylacetone, both thermally and photochemically.
- Cicogna, Francesca,Ingrosso, Giovanni,Lodato, Fabio,Marchetti, Fabio,Zandomeneghi, Maurizio
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- Carbohydrate-appended tumor targeting iron(III) complexes showing photocytotoxicity in red light
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Glucose-appended photocytotoxic iron(III) complexes of a tridentate Schiff base phenolate ligand [Fe(bpyag)(L)](NO3) (1-3), where bpyag is N,N-bis(2-pyridylmethyl)-2-aminoethyl-β-d-glucopyranoside and H 2L is 3-(2-hydroxyphenylimino)-1-phenylbutan-1-one (H 2phap) in 1, 3-(2-hydroxyphenylimino)-9-anthrylbutan-1-one (H 2anap) in 2, and 3-(2-hydroxyphenylimino)-1-pyrenylbutan-1-one (H2pyap) in 3, were synthesized and characterized. The complex [Fe(dpma)(anap)](NO3) (4), having bis-(2-pyridylmethyl)benzylamine (dpma), in which the glucose moiety of bpyag is substituted by a phenyl group, was used as a control, and the complex [Fe(dpma)(anap)](PF6) (4a) was structurally characterized by X-ray crystallography. The structure shows a FeN4O2 core in a distorted octahedral geometry. The high-spin iron(III) complexes with magnetic moment value of ~5.9 μB showed a low-energy phenolate-to-Fe(III) charge-transfer (CT) absorption band as a shoulder near 500 nm with a tail extending to 700 nm and an irreversible Fe(III)-Fe(II) redox couple near -0.6 V versus saturated calomel electrode. The complexes are avid binders to calf thymus DNA and showed photocleavage of supercoiled pUC19 DNA in red (647 nm) and green (532 nm) light. Complexes 2 and 3 displayed significant photocytotoxicity in red light, with an IC50 value of ~20 μM in HeLa and HaCaT cells, and no significant toxicity in dark. The cell death is via an apoptotic pathway, by generation of reactive oxygen species. Preferential internalization of the carbohydrate-appended complexes 2 and 3 was evidenced in HeLa cells as compared to the control complex 4. A 5-fold increase in the cellular uptake was observed for the active complexes in HeLa cells. The photophysical properties of the complexes are rationalized from the density functional theory calculations.
- Basu, Uttara,Khan, Imran,Hussain, Akhtar,Gole, Bappaditya,Kondaiah, Paturu,Chakravarty, Akhil R.
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p. 2152 - 2162
(2014/03/21)
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- Propargyl bromide as an excellent α-bromoacetone equivalent: Convenient and new route to α-aroylacetones
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A variety of α-aroylacetones 4a-g have been prepared in excellent yields following a new protocol wherein α-aminonitriles 1a-g as the aryl acyl anion equivalents readily react with propargyl bromide as the α-bromoacetone equivalent. The alkylated product undergoes one-pot unmasking of the keto functionality along with Markovnikov's hydration of the terminal alkyne with CuSO4·5H2O in aqueous methanol at 60 °C to furnish the desired target in excellent isolated yields.
- Mahalingam, Sakkarapalayam M.,Aidhen, Indrapal Singh
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p. 349 - 351
(2007/10/03)
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