No abstract

The first examples of amino-substituted fused-ring metallabenzenes, the cationic iridabenzofuran [Ir(C H O{NH -2}{OMe-7})(CO)(PPh ) ][O SCF ] (5) and neutral analogue Ir(C H {NH -2}{OMe-7})Cl(PPh ) (6), can be prepared by reduction of the corresponding nitro-substituted iridabenzofurans with zinc and concentrated hydrochloric acid. N-functionalised derivatives of 5 and 6 are formed through alkylation, sulfonylation or acylation. Thus, consecutive treatments with methyl triflate and base gives the corresponding trimethylammonium-substituted iridabenzofurans while sulfonamide derivatives are formed with p-toluenesulfonyl chloride. N-Acylation of 5 or 6 with acid chlorides, however, selectively form either amide or imide products depending on the charge on the metal and the steric size of the acid chloride. Cationic 5 gives amide substituted products regardless of the conditions whereas neutral 6 rapidly undergoes di-N-acylation with excess benzoyl chloride under mild conditions to give the imide-substituted product Ir(C H O{N[C(O)Ph] -2}{OMe-7})Cl(PPh ) (13). Selective mono-acylation of 6 can be achieved with one equivalent of benzoyl chloride or with excess of the sterically congested pivaloyl chloride.

A method for evaluating second sphere H-bonding interactions as a means to tune specific characteristics in coordinating ligands has been used to evaluate the binding strength of a series of beryllium complexes.

The chemistry of metallabenzenes and fused‐ring metallabenzenes continues to expand. Herein, we report the first simple amino‐substituted derivatives. Remarkably, these compounds were synthesized by reduction of the corresponding nitro‐iridabenzofurans with zinc and concentrated hydrochloric acid. The amino groups are readily functionalized, with selectivity controlled by the stoichiometry of the reactants, the steric bulk of the electrophiles, and the charge on the metal. More information can be found in the Full Paper by L. J. Wright et al. on page 4304.

What was the inspiration for this cover design?When we were invited to submit ac over suggestion, we tried to think of an eye-catching way to portray the key features of the new chemistry.S ince the chemistry involved nitro-substituted, fused-ring metallabenzenes undergoing remarkable transformations (first to amino and subsequently to imide and other derivatives), we were reminded of the breath-taking stunts that are associated with the "Nitro Circus." Our picture is therefore ap arody that shows our nitro-metallaaromatics with metallacyclic wheels undergoing amazing aerobatics. What prompted you to investigate this topic/problem?For the most part, we are driven by curiosity.I nt he area of metallaaromatics, there is still much that is unknown. The fact that no metallabenzenoid with ap rimary amino substituent (a very common functional group in chemistry) was known intrigued us. Thus, we resolved to prepare one and investigate how it behaved. What other topics are you working on at the moment?In addition to our research interests in the area of metallaaromatic chemistry,w ea re also engaged in developing and studying new ligand systems, especially those that contain pyridinium amidate donor groups. These act as very good supporting ligands for transition-metal catalysts, as well as for CO-releasing molecules. As part of our research in the area of green chemistry,w eare actively developing iron-based catalytic oxidation systems for water purification.Invited for the cover of thisi ssue is the group of L. J. Wright at the University of Auckland. The image depicts fused-ring metallabenzenesu ndergoing remarkable transformations. Read the full text of the article at