New main-group and early transition-metal complexes of mono-pendant arm triazacyclononane ligands

Reaction of 1,3,5‐Triazacyclohexanes with TiCl4: Formation of Cationic Complexes

“…[3,7,8] In an attempt to obtain analogous cationic titanium complexes with titanium free anions we added Me 3 SiOTf to the reaction mixture. Me 3 SiCl was formed, however, a crystal structure of the product, 4d, revealed the same cation not with an isolated triflate anion but with the titanium containing anion [Ti 2 Cl 6 (μ-Cl) 2 4 anions, although no pure samples could be obtained due to anion contamination. 5d had an NMR spectrum identical to the NMR tube experiment mentioned above and the spectra for 5b (4.91 and 4.30 ppm vs. 5.03 and 4.81 ppm in 3b) and for 5c (3.60 and 3.45 ppm vs. coinciding peaks at 4.83 for 3c) showed an increasing effect of the anion exchange (up-field shift and larger separation) for decreasing bulk of the N-substituents.…”

“…[1,2] They are used, for example, as bioinorganic model systems, reagents with high metal ion selectivity or as olefin polymerisation catalysts. The smaller N-substituted 1,3,5-triazacyclohexanes (R 3 TAC) are much easier to prepare by the reaction of formaldehyde with primary amines allowing for a large variety of alkyl substituents.…”

Use of Tetradentate Monoanionic Ligands for Stabilizing Reactive Metal Complexes

“…. [37] The bis-alkyl ] as potential precursors for Ti nitride species. [39] An alternative functionalized TACN ligand comes from Hessens group, who focused on the examination of an amido tether linked by either an ethyl or a dimethylsilyl bridge to the TACN moiety.…”

“…One of the first complexes reported was the dimethyl Al complex [Al(L e )Me 2 ], which exhibits hemilable behavior at the TACN moiety upon the abstraction of a methyl group with B(C 6 F 5 ) 3 (Scheme ) 36. In addition to Al chemistry, a range of trivalent main‐group and transition‐metal dichloride complexes were also synthesized through metathesis reactions with KL d–f and metal halide starting materials MCl 3 or MCl 3 (thf) 3 (M=Ga, In, Sc, Y, Ti, V, Cr) 37. The bis‐alkyl complex [Sc(CH 2 SiMe 3 ) 2 (L f )] was synthesized by the alkylation of [ScCl 2 (L f )] with two equivalents of LiCH 2 SiMe 3 or by the protonolysis reaction of HL f and [Sc(CH 2 SiMe 3 ) 3 (thf) 2 ].…”

Preparation and structure of an enantiomeric water-bridged dinuclear indium complex containing two homochiral N atoms and its performance as an initiator in polymerization of rac-lactide

“…The two indium atoms are equivalently coordinated in a molecule, which is consistent with the 1 H NMR spectrum of 1. [6,21,22].…”