Olivier Siri

Unprecedented zwitterion in quinonoid chemistryElectronic supplementary information (ESI) available: spectroscopic data for 4 and 6 and an ORTEP view of the structure of 4. See http://www.rsc.org/suppdata/cc/b1/b107828n/.

The first 12 pi-electron zwitterionic structure in quinonoid chemistry is described with the N,N,O,O-molecule 6 in which the positive charge is pi-delocalized between the nitrogen atoms and the negative charge between the oxygen atoms; depending on the crystallization solvent, a 1D-tape-like H-bonded network can be generated in the solid-state.

Coplanar conjugated β-nitroporphyrins and some aspects of nitration of porphyrins with N2O4

Abstract Sterically controlled N 2 O 4 nitration of a meso -2,3-unsubstituted porphyrin or a bis-α-unsubstituted pyrroloporphyrin affords coplanar conjugated β-nitroporphyrins displaying strong electronic interactions.

A TWO STEP SYNTHESIS OF THE NEW OCTACYCLAM AND SOME OTHER OCTAAZACYCLOALKANES VIA REDUCTION OF TETRAAMIDE INTERMEDIATES

Abstract A convenient two step synthesis of new octaazamacrocycles via a 2+2 condensation of tetraamines and diethyloxalate followed by the reduction of the tetraamide intermediates is reported. This methodology can be applied to the preparation of other large polyazamacrocycles which might exhibit interesting complexing properties as anion receptors.

Linear fused oligoporphyrins: potential molecular wires with enhanced electronic communication between bridged metal ions

Syntheses of nanometer scale, directly beta-fused oligoporphyrins sharing an extended π-system are described.

β-Cyano meso-unsubstituted porphyrins for intramolecular charge transfer

Abstract β-Cyano meso -unsubstituted porphyrin 10 , synthesized via a ‘3+1’ condensation using a bromotripyrrane, shows an effective charge transfer interaction across the porphyrin between electron-acceptor and -donor groups in β-positions.

One-pot synthesis, physicochemical characterization and crystal structures of cis- and trans-(1,4,8,11-tetraazacyclotetradecane)-dichloroiron(III) complexes†

The synthesis and characterization of cis- and trans-[Fe(cyclam)Cl2]+ (cyclamxa0=xa01,4,8,11-tetraazacyclotetradecane) are described. The assignment of geometrical configuration to these complexes has been made on the basis of their infrared spectra in the 800–900 cm–1 region. In addition, the molecular structures of the cis and trans derivatives were determined by X-ray diffraction. Both complexes have a d5 electronic system, the cis and trans species being respectively in a high spin and a low spin configuration. These two isomers are fully characterized by electrochemistry and they are simultaneously observed in the reaction mixture by cyclic voltammetry. This study shows that the reactivity towards dioxygen of the two reduced isomers is different, and that the formation of the oxygenated species is not observed in some solvents.

Synthesis and characterization of 3,3,10,10-tetramethyl-1,5,8,12-tetraazacyclotetradecane. A new route to macrocyclic polyamides and polyamines

Abstract The 1:1 and 2:2 cyclization reactions were simultaneously observed by addition of diethyl oxalate on 3,3,10,10-tetramethyl-1,5,8,12-tetraazadodecane. The resulting 1:1 cyclisation product was fully characterized by spectroscopy and X-ray diffraction study. The reduction of this compound gives the 3,3,10,10-tetramethyl-1,5,8,12-tetraazacyclotetradecane with a high yield.