Reactivity of Triosmium and Triruthenium Carbonyls with 2,2‘-Diamino-1,1‘-binaphthalene. Synthesis of C-and N-Metalated Derivatives

Abstract

The reaction of [Os3(MeCN)2(CO)10] with 2,2‘-diamino-1,1‘-binaphthalene (H2binam) affords the coordinatively unsaturated trinuclear derivative [Os3(μ-H)(μ3-η2-Hbinam-N,C)(CO)9] (1), which contains a C-metalated Hbinam ligand attached to an Os atom through an NH2 group and to the remaining two Os atoms through the metalated C atom. The unsaturation of 1 is somewhat relieved by a weak interaction of a naphthalene CC double bond with an Os atom. Curiously, treatment of [Ru3(MeCN)2(CO)10] with H2binam does not give the ruthenium analogue of 1. The stepwise treatment of [Ru3(CO)12] with LiHbinam and [HOEt2][BF4] leads to [Ru3(μ-H)(μ-η1-Hbinam-N)(CO)10] (2), in which an N-metalated Hbinam acts as an edge-bridging amido ligand. Complex 2 reacts with bis(diphenylphosphanyl)methane (dppm) to give [Ru3(μ-H)2(μ3-η2-binam-C,N)(μ-η2-dppm-P,P)(CO)7] (3). This complex contains a doubly C- and N-metalated binam ligand attached to a Ru atom through the metalated C atom and to the remaining two Ru atoms through the metalated NH fragment. Compounds 1 and 3 are the first examples of C-metalated derivatives of H2binam.

Synthesis, structure, photophysical and electrochemical behavior of 2-amino-anthracene triosmium clusters

“…The first reversible 1e − reduction observed for 4 is reminiscent of the previously reported triosmium cluster complexes of aromatic nitrogen heterocycles containing a formally 3center-2-electron bond with a carbocyclic ring in a 46e − species [6,22] and generalizes the electron acceptor properties of this bonding mode to complexes containing exocyclic as well as endocyclic amine groups [8]. However, within this class of molecules only one example of a complex that has two reversible reductions exists; a 4-carboxaldehyde quinoxaline complex while the behavior of 4 is distinctly different in that the second reduction only approaches reversibility at CV scan rates of 400 mV/s [6].…”

“…The pathway proposed for this conversion is by no means a unique explanation of this observation but the increased rate of the conversion in the presence of D 2 O and the detection of what appears to be a deuterium containing peak seems to at least point to water as the catalyst for this process. The formation of 4 from 2 and its reversible 1e − electrochemical behavior further illustrates the generality of the electron acceptor properties of the μ 3 -η 2 -electron deficient bonding mode [2,8]. Overall the photophysical properties and the electrochemical properties of the reported complexes do not differ drastically from the free ligand except in the case of 4.…”

“…Here again, the ability for the metal core to communicate with the organic ligand via the electron deficient μ 3 -η 2 -bonding mode proved to be an important factor in determining the overall stability of the radical anions produced by reduction. Recently, it has been shown that this type of bonding mode can result from the reaction of an aromatic carbocycle containing exocyclic amine substituents [8]. Also, there have been recent reports that metal complexes of anthracene are particularly good intercalators into the major groove of DNA [9].…”

21 Organometallic chemistry of bi- and poly-nuclear complexes

“…43 The first examples of triosmium carbonyl clusters containing m 3 -NH nitrene ligands have also been reported, 44 as have some related complexes derived from 2,2'diamino-1.1'binaphthalene. 45 The novel m 4 -oxo cluster [Os 6 (CO) 16 remarkably good (32%) yield. Crystallographic analysis revealed an unusual cluster core geometry, which can be described as a distorted square pyramid with three of the basal edges shared by three tetrahedral fragments, together with a trigonal facecapping Os atom.…”

Di‐ and Trinuclear Ruthenium and Osmium Bis(2‐pyridyl) Ketone Oximate Derivatives

“…However, this is not always the case for other ligands, such as bis(2-pyridyl)-amine, [13] 2-amino-7,8-benzoquinoline, [14] or 2,2Ј-diamino-1,1Ј-binaphthalene. [15] Bearing in mind that the triruthenium complex 3 is an intermediate in the formation of 1, we reasoned that complex 4 could be a suitable precursor of a triosmium cluster isostructural with complex 1. Indeed, treatment of complex 4 with Hdpko in toluene at reflux temperature allowed the isolation of [Os 3 (µ,η 3 -dpko-N,N,O) 2 (CO) 8 ] (5).…”