Protonation of 9-(ferrocenylethynyl)fluoren-9-ol (9) yields the conjugated enone derived from a Meyer-Schuster rearrangement. However, treatment of 9 with thionyl chloride at -30°C proceeds with elimination of SO 2 to furnish 3,3-biphenylene-1-chloro-1-ferrocenylallene (14), the 13 C NMR data of which indicate that the central carbon does not have markedly carbenic character. Upon warming, this allene readily forms the sterically highly encumbered head-to-head dimer 15, whereby the 1,2-bis(alkylidene)cyclobutane adopts a butterfly conformation with two exocyclic Cl(Fc)Cd moieties and a very long (∼1.65 Å) C(3)-C(4) bond linking the two spiro-bonded fluorenyl fragments. In contrast, attempts to generate the analogous ferrocenylbromoallene 16 instead yielded the hexa-1,2-dien-5-yne 17, the product of allenyl radical head-to-tail coupling. Protonation of ferroceno[2,3]inden-1-ol (25) confirmed a proposal, originally put forward by Caïs in 1965, concerning the possible diradical nature of the resulting cation; the unambiguous characterization of the ferroceno[2,3]inden-1-yl dimer (29) provides experimental verification of Caïs's hypothesis. The X-ray crystal structures of 9-(ferrocenylethynyl)fluoren-9-ol (9) and of its isomer 1-(phenylethynyl)ferroceno[2,3]inden-1-ol (26) are reported along with, among others, the structures of 15, 17, 25, and 29. The possible role of these allenes as precursors to ferrocenylcontaining electroluminescent tetracenes is discussed.

A new redox amphiphilic ionic liquid (AIL) containing ferrocene as a redox-active group was synthesized, 1-(11-ferrocenylundecyl)-3-methylimidazolium bromide (Fc11MIm+). Adsorption and aggregation of both reduced and oxidized forms of this ferrocenated AIL in aqueous solution were studied by surface tension measurements. The micellization was favored for the reduced ferrocenated AIL (Fc11MIm+) as compared with the oxidized ferrocenated AIL (Fc+11MIm+). Minimum areas at the air/aqueous solution interface were identical whereas limiting surface tensions were slightly different. This corroborated the formation of an expanded monolayer of redox active AIL at the interface. The electrochemical behavior of redox active AIL was investigated. The electrochemical responses of Fc11MIm+ aqueous solution interestingly differed, depending on its concentration. Below the cmc, the electrochemical reaction was dominated by ferrocenated AIL adsorbed onto the electrode surface; then above the cmc, it was controlled by the Fc11MIm+ diffusing to the electrode. For the latter, the electrochemical mechanism was suggested to couple with the disruption reaction of the reduced form micelles.

The synthesis of Cr(CO) 3 -complexed aromatic nitrones 2 is reported. These new planar-chiral complexes were fully characterized in solution by 1 H and 13 C NMR, IR and cyclic voltammetry. Moreover, structural data were obtained from X-ray structures of nitrones 2b, 2d, 2e and 2f. These analyses converge to give evidence of a favoured anti conformation of ortho-substituted nitrones, with an unusual N-O···H aryl intra-