Synthesis, characterization, and polymerization activity of (pentamethylcyclopentadienyl)titanatranes containing {(O-2,4-Me2C6H2-6-CH2)nN(CH2CH2O)3−n}3− (n=0–2) or {N(C6H4-2-O)3}3−

Magnetic, electrochemical and spectroscopic properties of iron(iii) amine–bis(phenolate) halide complexes

“…39,57,59 However, they are shorter than the average Fe-O bond length of 1.92 Å observed in octahedral Fe(III) complexes. 42,44,45,[61][62][63] The Fe-Br and Fe-N bond distances are in the ranges of 2.4034 (16) 9)°, causing the other angles to pinch in. In summary, subtle structural deviations can occur as a result of seemingly minor modifications at both the 4-position of the phenolate ring and the pendant ether group.…”

“…[28][29][30][31][32][33] These ligands are very well suited to stabilizing electron-deficient, high oxidation-state metal centers due to the strong π-donor ability of the phenolate groups. In particular, these systems have been shown to be excellent for the stabilization of high-valent organometallic systems, such as Ti(IV), [10][11][12][13][14][15][16][17][18][19][20] Zr(IV) 3,[11][12][13][21][22][23][24][25] and Ta(V)-complexes, 5,17,26,27 which have primarily been used as polymerization catalysts. These extremely versatile and modifiable ligands are also being used with the mid-to-late transition metals.…”

Synthesis and Structural Analysis of Titanatranes Bearing Terminal Substituted Aryloxo Ligands of the type [Ti(OAr){(O-2,4-Me2C6H2-6-CH2)2(OCH2CH2)N}]n (n = 1, 2): Effect of Aryloxo Substituents in the Ethylene Polymerization

“…There has been immense research interest in designing various metal complexes containing tripodal trianionic donor (called “atrane”) ligands, such as tris(amido)amine, tris(alkoxo)amine, and tris(aryloxo)amine. − These trianionic donor ligands, usually bind to a transition metal in a tetradentate manner and are capable of providing a range of stable steric and electronic environments for (catalytically active) metal centers. The perfect combination consisting of the exocylic axial group and a flexible transannular bond between an axial nitrogen atom (of the tripodal ligand) and a metal ion generates a pseudo 3-fold symmetric environment (like a specific pocket around the metal center) .…”

“…There have been many reports for synthesis, structural analysis, and some reactions not only of main group atranes (silatranes, phosphatranes, etc. ) − , but also of the transition metal complexes containing atrane ligands, ,,,− especially titanatranes. ,,,,− Some successful examples, such as applications as catalysts for organic synthesis by titanatranes , and the catalytic dinitrogen activation by molybdenum complexes, were well-known. Moreover, applications using titanatranes as the catalyst precursors for syndiospecific styrene polymerization , and lactide polymerization were known.…”