Indolocarbazole-based ligands for ladder-type four-coordinate boron complexes.

A novel class of π-conjugated systems, which combine the indolo[3,2-b]carbazole unit with the formation of four-coordinate boron complexes, is presented. The resulting conjugated compounds have a double-laddered structure that provides interesting optical and electrochemical properties. The wide absorption range, covering most of the visible spectrum, along with the narrowing of the HOMO-LUMO energy gap, due to the presence of diphenylboryl centers, reinforces the potential of these molecules within the area of organic electronics.

Synthesis, structural charaterization, and electrochemical and optical properties of ferrocene-triazole-pyridine triads.

The synthesis and electrochemical, optical, and cation-sensing properties of the ferrocene-triazole-pyridine triads 3 and 5 are presented. Azidoferrocene 1 and 1,1'-diazidoferrocene 4 underwent the "click" reaction with 2-ethynylpyridine to give the triads 3 and 5 in 81% and 68% yield, respectively. Electrochemical studies carried out in CH(3)CN in the presence of increasing amounts of Zn(2+), Ni(2+), Cd(2+), Hg(2+), and Pb(2+) metal cations, showed that the wave corresponding to the ferrocene/ferrocenium redox couple is anodically shifted by 70-130 mV for triad 3 and 167-214 mV for triad 5.

Unprecedented 1,3-diaza[3]ferrocenophane scaffold as molecular probe for anions.

The guanidine unit in the guise of 2-aminoimidazole in the new structural motif 2-arylamino-1,3-diaza[3]ferrocenophane 4 acts as a binding site for anions. The electrochemical behavior of this compound has been studied by cyclic voltammetry (CV) and differential pulse voltammetry (DPV) and was found to exhibit a quasi reversible oxidation peak, associated to the Fe(II)/Fe(III) redox couple (Ep = 440 mV), and a non-reversible oxidation wave (Ep = 817 mV), probably associated to the oxidation of the C═N unit present in the guanidine bridge. Recognition of AcO(-), PhCO(2)(-), F(-), Cl(-), and Br(-) anions by the free receptor and the less basic anions Br(-), Cl(-), and NO(3)(-) by its monoprotonated form takes place by unusual redox-ratiometric measurements and spectroscopic ((1)H NMR and UV-vis) changes.

A new building block for anion supramolecular chemistry. Study of carbazolocarbazole as anion receptor.

A novel carbazolocarbazole system has been evaluated as an anion receptor in DMF solution. A good affinity has been detected for oxoanions. The anion binding studies have been contrasted by different experimental techniques.

Synthesis and characterization of new carbazolocarbazoles: toward pi-extended N-fused heteroacenes.

A regiospecific route has been developed for the synthesis of carbazolo[1,2-a]carbazole. The synthetic strategy is based on the use of appropriately tetrasubstituted naphthalene. Optical and electrochemical characterization of the fused heteroaromatic system reveals that this optically transparent heteroacene, with a low-lying HOMO, might be used as an organic material.