Structural and spectroscopic characterizations of aluminum phenoxide

Abstract

A synthetic route to obtain crystalline aluminum phenoxide was established. Its molecular structure in solid-state and solution is unambiguously determined by single-crystal X-ray diffraction and (1)H, (13)C and (27)Al NMR spectroscopy. The single-crystal X-ray analysis revealed the presence of the dimeric THF adduct [Al(OPh)3·THF]2 with a disordered trigonal bipyramidal geometry at the aluminum atom which is bonded to a THF ligand, two terminal and two bridging phenoxy groups (OPh). The solution behavior of the title compound was investigated by (27)Al NMR in non-coordinating (CDCl3) as well as coordinating (THF) solvents at different temperatures. The obtained results indicate the presence of four- and five-coordinate species in solution.

Synthesis, Structural Studies, and Application of Aluminum Aryloxides for Ring-Opening Metathesis Polymerization

“…The oxygen atoms of the terminal and bridged aryloxide ligands and coordinated THF molecule form the distorted tetragonal bipyramidal coordination environment at the aluminum ion. The dimeric aggregation motif observed in [ 1· (thf)] 2 · (THF) 2 is similar to that found previously for aluminum phenoxide . The Al(1)–O(4) and Al(1)–O(4)* bonds within the central [Al­(μ-OAr) 2 Al] core are notably longer (1.832(2) and 1.917(2) Å) compared to the related Al(1)–O(1) and Al(1)–O(2) bonds involving the terminal aryloxides ligands (1.729(2) and 1.745(2) Å).…”

“…The 27 Al nuclear magnetic resonance (NMR) was employed to study the aggregation behavior for newly prepared compounds 1−7 in the THF-d 8 solution. Ultimately, we found that the resonance signal at δ( 27 Al) = 70 ppm, previously assigned to four-coordinated aluminum ions in aluminum aryloxide, 18 is apparently attributed to the background coming from the NMR probe of the spectrometer (Figure S1). A broad resonance signal around δ( 27 Al) = 30 ppm was detected in the series of homoleptic aryloxides 1−3.…”

Complexation of Boron and Aluminum with a Bidentate Hydroxy-BN-naphthalene Ligand

“…Table S2: Coordinates of the geometry-optimized structures. Reference [51] is cited in the supplementary materials. Funding: This research received no external funding.…”

Reactivity studies and structural outcomes of a bulky dialkylaluminium amide in the presence of the N-heterocyclic carbene, ItBu

“…The Al-O distances span the range 1.763(1)-1.795(1) Å, which is marginally longer than those typically seen in terminal Al-O (phenoxy) bonds in neutral aluminium complexes such as Al2(OPh)6‧2THF [1.734(3) Å]32 or (tBu2(OPh)Al)2‧(µ-4,4'-bipy) [1.719(5) -1.755(4) Å].…”