Coinage Metal Complexes of a Tellurium Diimide:cis→trans Isomerization and Metal-Metal Interactions

Abstract

The different coordination behavior of the ligand tBuN=Te(µ-NtBu)(2)Te=NtBu (L) towards Cu(+) and Ag(+) results from a cis-->trans isomerization. The two Cu(+) ions in [Cu(2)L(3)](2+) (shown schematically) bridge trans and cis isomers of the ligand, whereas the Ag(+) ions in [Ag(2)L(2)](2+) link two trans ligands and exhibit a weak Ag small middle dot small middle dot small middle dotAg interaction.

Reactions of cis-[tBuNTe(μ-NtBu)]2 with CF3SO3Me and M[O3SCF3] (M = Ag, Cu): Chelation, Cis → Trans Isomerization, and the Spirocyclic Ligand [tBuNTe(μ-NtBu)2Te(μ-O)]2

“…For example, the cis isomer may function as a chelating ligand, whereas the trans isomer could serve as a bridging ligand in a coordination polymer. With these possibilities in mind, our initial studies of the coordination complexes of 1a have focused on the coinage metals . Solubility in organic solvents and the low nucleophilicity of the [CF 3 SO 3 ] - anion were attractive features of the electrophilic reagents M[O 3 SCF 3 ] (M = Ag, Cu) for this investigation.…”

“…With these possibilities in mind, our initial studies of the coordination complexes of 1a have focused on the coinage metals. 9 Solubility in organic solvents and the low nucleophilicity of the [CF 3 SO 3 ]anion were attractive features of the electrophilic reagents M[O 3 SCF 3 ] (M ) Ag, Cu) for this investigation. The products of the reaction of 1a with MeO 3 SCF 3 were also characterized in order to provide spectroscopic benchmarks for complexes formed from 1a and metal triflates.…”

New tellurium-containing ring systems

“…The hexameric complex 21 exhibits an unprecedented twelve-membered ring structure ( interaction should be considered [28]. However, this close approach may simply be a result of the conformational flexibility of the twelve-membered ring in 21 combined with the need to minimize interactions between iso-propyl groups.…”

7 Oxygen, sulfur, selenium and tellurium

“…18 Attempts to con¢rm the structure by X-ray crystallography were hampered by disorder problems. Moving further down the group, a number of Te^N systems have been reported by Chivers et al The reactions of the dimeric tellurium diimide [Bu t NTe(m-NBu t ) 2 TeNBu t ] with metal salts 19 and with tellurium halides 20 have been reported. In the ¢rst case a very different ligand behaviour towards Cu(I) is observed compared to that with Ag(I); in the copper product (of formula [Cu 2 L 3 ] 2 ) the copper atoms bridge trans and cis isomers of the ligand while silver links two trans ligands in its product dinuclear [Ag 2 L 2 ] 2 .…”