Hydrogen-bonded and π-inter­action assembly in two 8-alk­oxy­carbonyl-1,8-diaza­bicyclo­[5.4.0]undec-7-enium chloride salts

The crystal structures of 8-phen­oxy­carbonyl-1,8-diaza­bicyclo­[5.4.0]undec-7-enium chloride, C₁₆H₂₁N₂O₂⁺·Cl⁻, (I), and 8-meth­oxy­carbonyl-1,8-diaza­bicyclo­[5.4.0]undec-7-enium chloride monohydrate, C₁₁H₁₉N₂O₂⁺·Cl⁻·H₂O, (II), recently reported by Carafa, Mesto & Quaranta [Eur. J. Org. Chem. (2011), pp. 2458–2465], are analysed and discussed with a focus on crystal inter­action assembly. Both compounds crystallize in the space group P2₁/c. The crystal packings are characterized by dimers linked through π–π stacking inter­actions and inter­molecular nonclassical hydrogen bonds, respectively. Additional inter­molecular C—H...Cl inter­actions [in (I) and (II)] and classical O—H...Cl hydrogen bonds [in (II)] are also evident and contribute to generating three-dimensional hydrogen-bonded networks.

The correct assignment of stereochemistry in di-μ-dichlorido-bis­{bis­[2-(5-benzyl­sulfonyl)-3-fluoro-2-(pyridin-2-yl)phenyl-κ²N,C¹]iridium(III)} toluene monosolvate

The title complex, [Ir₂(C₁₈H₁₃FNO₂S)₄Cl₂]·C₇H₈, was crystallized from dichloro­methane solution under a toluene atmos­phere. It is a dimeric complex in which each of the two Ir^III centres is octa­hedrally coordinated by two bridging chloride ligands and by two chelating cyclo­metalated 2-(4-benzyl­sulfonyl-2-fluorophenyl)pyridine ligands. The crystal structure analysis unequivocally establishes the trans disposition of the two cyclo­metalated ligands bound to each Ir^III centre, contrary to our previous hypothesis of a cis disposition. The latter was based on the ¹H NMR spectra of a series of dimeric benzyl­sulfonyl-functionalized dichloride-bridged iridium complexes, including the compound described in the present work [Ragni et al. (2009). Chem. Eur. J. 15, 136–148]. The toluene solvent mol­ecules, embedded in cavities in the crystal structure, are highly disordered and could not be modelled successfully; their contribution was removed from the refinement using the SQUEEZE routine in the program PLATON [Spek (2009). Acta Cryst. D65, 148–155].