Ethynyl and Ethenyl Ferrocenyl Dyads with Acridine, Acridone, and Anthraquinone

Abstract

Ethynylferrocenyl derivatives of 2,7-acridine (1, 2), 9-N-acridone (4), and 2-anthraquinone (6) are described. (Z)-10-(2-iodo-1-ethenylferrocene)-9(10H)-acridinone (3), an intermediate in the formation of 4, N-Fc(CH2) n -acridone (5; n = 8, 11), 1-Fc-anthraquinone (7), and (E)-(2-FcCC)-anthraquinone (8) were also investigated. The X-ray structures of 3 and 6 were determined. B3LYP calculations, UV/vis spectroelectrochemistry, cyclic voltammetry, and ESR spectra were used to probe the ground and excited states of both the neutral and oxidized compounds. Emission is observed from oxidized, but not neutral, 4 and 6; however, 1, 2, and 8 are fluorescent. Surprisingly, emission is reduced upon oxidation of 2 and 8, which appears to correlate with the greater distortion in the excited compared to ground states.

Synthesis and electro-spectroelectrochemistry of ferrocenyl naphthaquinones

“…Similar behavior was reported in the literature where the oxidation potential of the Fc þ /Fc couple (0.60 V) observed for 1-ferrocenylanthraquinone, directly linked acceptoredonor units, showed only a slight anodic shift compared to that of the ferrocene molecule (0.55 V) in CH 2 Cl 2 . 37 The difference between the half-wave potentials of the oxidation and first reduction processes [ 1 DE p ¼E 1/2 (Fc þ enq/Fcenq)ÀE 1/2 (Fcenq/ Fcesnq À )], relating to the energy of the intramolecular chargetransfer transition between the ferrocenyl donor and naphthaquinonyl acceptor centers [e p (HOMOeFc)/e p * (LUMOenq)], was ranged between 1.21 and 1.47 V according to substitution pattern. The 1 DE p values showed a good agreement with the maximum absorption wavelengths of the intramolecular charge-transfer.…”

N-(4-Ferrocenylphenyl)-4-piperidino-1,8-naphthalimide

“…We have a long-standing interest in molecules that contain both¯uorescent and redox centres, particularly when such centres are joined by potentially conductive links (McAdam et al, 1999, 2000, McGale et al, 2003. As part of these investigations, the title compound, (I), in which the ferrocene redox centre is linked to the naphthalimide¯uorophore via a phenylene bridge, was prepared from the reaction of 4-bromonaphthalic anhydride and ferrocenylaniline followed by replacement of the bromo substituent in boiling piperidine.…”

DNA Photocleavage and Cytotoxic Properties of Ferrocene Conjugates

“…cenium species upon photoactivation could be of importance as bioorganometallic agents in the photodynamic therapy (PDT) of cancer. [13][14][15][16] The concept of using hitherto unknown bioorganometallic species as potential PDT agents originates from the successful use of porphyrin and phthalocyanine bases as photochemotherapeutic agents to treat cancer in a noninvasive method in which the cancer cells are selectively photoexposed to visible light to generate singlet oxygen as the reactive oxygen species, thus leaving the unexposed healthy cells unaffected. [17][18][19][20] Metal-based PDT agents that show significant photocytotoxicity with reduced dark toxicity have recently been reported as alternatives to organic PDT agents.…”