Synthesis, molecular and electronic structure of complexes [LNaM^IVNaL](MRu,Os; H₃L = 1,4,7-tris(4-tert-butyl-2-mercaptobenzyl)-1,4,7-triazacyclononane)

Abstract

The trinuclear complexes [LNaMlvNaL] (M = Ru 1, 0 s 2) where L represents the hexadentate ligand 1,4,7-tris(4-tertbutyl-2-mercaptobenzyl)-l,4,7-triazacyclononane have been synthesized and 1 has been characterized by X-ray crystallography; complex 1 contains an octahedral M'VS6 central core and two trigonal-prismatic terminal LNa units with an N3S3 donor set; the electronic structure of the MlvSs core (M = Ru, Os), has been established as S = 1 by temperature-dependent magnetic susceptibility measurements.

Redox Chemistry of (1,4,7-Tris(4-tert-butyl-2-mercaptobenzyl)-1,4,7- triazacyclononane)ruthenium(III), [RuIIIL]: Synthesis and Characterization of [RuII2(L−L)](BPh4)4·10CH3CN and [LRuRuRuL](PF6)2·H2O

“…The pendent arm macrocyclic ligand H 3 L in its deprotonated trianionic form has been shown to form a wide variety of very stable mono-, di-, and trinuclear transition metal complexes (Chart ): [M III L] (M = Ga, In, V, Cr, Mn, Fe, Co) and [M IV L]PF 6 (M = V IV , Mn IV ), homo- and heterodinuclear species [LM II 2 Cl] and [LM 1 M 2 Cl],1c and homo- and heterotrinuclear species [L 2 M 3 ] n + and [LM 1 M 2 M 1 L] n + are readily synthetically accessible; − L 3- represents the trianion of 1,4,7-tris(4- tert -butyl-2-mercaptobenzyl)-1,4,7-triazacyclononane. In mononuclear octahedral complexes, a cis -N 3 S 3 M coordination polyhedron allows one to bind a second transition metal ion at the three thiolato sulfur donor atoms in cis positions relative to each other.…”

“…In the linear trinuclear species, the central metal ion possesses an octahedral MS 6 polyhedron. This central moiety was recently shown to stabilize transition metal ions in rare high oxidation states as in [LCo III Cu III Co III L] 3+ , [LNaRu IV NaL] 0 , and [LNaOs IV NaL] 0 . , All species have a rich redox chemistry, which allows one to characterize isostructural oxidized and reduced species of a given complex and study spin-exchange phenomena as a function of the individual d n electron configurations of given metal ions in an identical ligand matrix…”

“…This central moiety was recently shown to stabilize transition metal ions in rare high oxidation states as in [LCo III Cu III Co III L] 3+ , [LNaRu IV NaL] 0 , and [LNaOs IV NaL] 0 . 3,4 All species have a rich redox chemistry, which allows one to characterize isostructural oxidized and reduced species of a given complex and study spin-exchange phenomena as a function of the individual d n electron configurations of given metal ions in an identical ligand matrix. 5 Here we report the synthesis and properties of [Ru III L] (1), which can be chemically or electrochemically oxidized by two electrons per Ru ion, yielding a dinuclear species containing two reduced ruthenium(II) ions, [Ru II 2 (L-L)](PF 6 ) 4 (2), where (L-L) represents the neutral dimeric, six-electron oxidized form of the L 3ligand containing three disulfide groups (Scheme 1), eqs 1 and 2.…”

Mono- and Dinuclear Transition Metal Complexes of the Hexadentate Ligand Tris(4-tert-butyl-2-mercaptobenzyl)-1,4,7-triazacyclononane (L)

“…Here we report its synthesis (Scheme ) and a series of mono- and dinuclear complexes. Its remarkable ability to bind even to sodium and to form trinuclear complexes was recently shown by the synthesis of the complex [LNaRu IV NaL] and its osmium(IV) analogue 1 Synthesis of the Ligand H 3 L·3HCl …”

A General Route for the Synthesis of Triazacyclononane Functionalised with Pendant Phosphane Arms − Crystal Structures of [NiL1Cl(HOEt)][ClO4] and [NiL1(NCS)2] with L1 =N-(Diphenylphosphanylpropyl)-1,4,7-triazacyclononane

“…[1] Ϫ [3] There are a few recent examples of functionalisation by soft donor arms, for example 4-mercaptobenzoyl, [4] ϪCH 2 CH 2 SH [5] and 2-mercaptobenzyl, [6] but so far 9[ane]N 3 has not been functionalised with pendant arms ending in a phosphane group. [7] When this work was started there were only two published examples of nitrogen macrocycles with pendant phosphane arms: 1,4,8,11-tetrakis[(diphenylphosphanyl)methyl]-1,4,8,11-tetraazacyclotetradecane which is prepared by a ''one-pot'' synthesis [8] which cannot be generalised, and a series of N 2 O 2 , N 2 S 2 and NO 3 macrocycles with 2-phosphanylethyl arms.…”