The group 13 metal complexes of sterically-hindered substituted iminophenol: synthesis and structure

Abstract

The synthesis of complexes I–IV.

2-Imino-2,3-dihydrobenzoxazole—a useful platform for designing rare- and alkaline earth complexes with variable di- and trianionic O,N,N, ligands

“…The methyl group attached to the imino carbon appears as a singlet at 1.76 ppm, while the methylene group gives two singlets at 4.24 and 4.85 ppm. In the 13 In order to evaluate the LH ligand as a supporting coordination environment for the synthesis of mixed-ligand rareearth alkyl species, the alkane elimination protocol was applied. The reaction of Y(CH 2 SiMe 3 ) 3 (THF) 2 with one equivalent of LH was carried out in hexane at 0 °C which led to the formation of mono(alkyl) Y complex 4 that was isolated as a red microcrystalline powder after recrystallization from a hexane/DME (3 : 1) mixture (Scheme 5) in a 55% yield.…”

“…The reaction of Y(CH 2 SiMe 3 ) 3 (THF) 2 with one equivalent of LH was carried out in hexane at 0 °C which led to the formation of mono(alkyl) Y complex 4 that was isolated as a red microcrystalline powder after recrystallization from a hexane/DME (3 : 1) mixture (Scheme 5) in a 55% yield. According to the 1 H and 13 C NMR spectra, 4 is a mono(alkyl) complex coordinated by the dianionic imino-amidophenolate ligand that resulted from the alkane elimination accompanied by the migration of one alkyl group to one CvN bond of the L ligand. 43,44 The latter reaction along with the migration of the alkyl group to the carbon atom of the CvN bond comprises the formation of a covalent Y-N bond.…”

“…[3][4][5][6] Schiff base ligands have been extensively studied mainly due to their coordination abilities, facile syntheses, easily tunable steric factors, and electronic properties. [7][8][9][10][11] In 2014, Abakumov and co-workers reported on the synthesis, structure and intramolecular cyclization-decyclization of new sterically hindered diiminophenol 12,13 and complexation of the cyclic tautomer 2-imino-2,3-dihydrobenzoxazole LH (Scheme 1) with 12 and 13 group metals was investigated. 12,13 The combination of a variety of possible coordination modes of cyclic and acyclic tautomers of LH 12,13 with large sizes characteristic of rare-earth ions 3 provides a basis for rich coordination chemistry.…”

“…[7][8][9][10][11] In 2014, Abakumov and co-workers reported on the synthesis, structure and intramolecular cyclization-decyclization of new sterically hindered diiminophenol 12,13 and complexation of the cyclic tautomer 2-imino-2,3-dihydrobenzoxazole LH (Scheme 1) with 12 and 13 group metals was investigated. 12,13 The combination of a variety of possible coordination modes of cyclic and acyclic tautomers of LH 12,13 with large sizes characteristic of rare-earth ions 3 provides a basis for rich coordination chemistry. Moreover, due to the presence in the acyclic form of a pendant redox active diimino fragment able to oxidize electropositive Ln(II) [14][15][16][17][18] centres unique redox reactivity can be expected in the case of Ln metals possessing two stable oxidation states.…”

Structural, Non-Covalent Interaction, and Natural Bond Orbital Studies on Bromido-Tricarbonyl Rhenium(I) Complexes Bearing Alkyl-Substituted 1,4-Diazabutadiene (DAB) Ligands

“…By changing the electronic and steric effects in the DAB ligands in their Ni(II) and Pd(II) complexes, they can be utilized as efficient catalysts in alkene polymerization [17,18]. The tuning of such electronic and steric effects has been examined before in some iminophenol complexes [19,20]. Besides all the aforementioned properties, one of the interesting features of metal carbonyl complexes is the presence of intra-and/or intermolecular n .…”