Structural Diversity in a Series of Alkyl-Substituted Cesium Aryloxides

Abstract

A family of cesium aryloxides [Cs(OAr)](n) were synthesized and structurally characterized from the reaction of 1:1 or 1:excess stoichiometry of Cs(0) and the appropriate alkyl-substituted phenol: 2-alkylphenol [alkyl = methyl (H-oMP), isopropyl (H-oPP), and tert-butyl (H-oBP)] and 2,6-dialkylphenol [alkyl = methyl (H-DMP), isopropyl (H-DIP), tert-butyl (H-DBP), and phenyl (H-DPhP)]. The products were structurally identified as [Cs(oMP)(H-oMP)(2)](n) (1), [Cs(5)(oPP)(5)](n) (2), [Cs(4)(oBP)(4)(H-oBP)(6)](n) (3x, shown), [Cs(3)(DMP)(3)](n) (4), [Cs(2)(DIP)(2)](n) (5), [Cs(DIP)(H-DIP)](n) (5x), and [Cs(DPhP)](n) (7). Compounds 1-7 were found to adopt complex polymeric structures employing π interactions from the neighboring pendant phenoxide ligands. The solution behavior of these compounds was studied using solution (133)Cs NMR spectroscopy, and for each compound, a single (133)Cs NMR resonance was observed, with chemical shift values found to be strongly solvent-dependent. This implies that monomeric cesium salt species involving solvent interactions exist in solution.

Reshaping Rubrene by Controlled Reduction with Alkali Metals

“…[8a,9] This observation shows only one type of Li + ions coordinated to the rubrene dianion surface in solution. The broadness and significant up-field shift, compared to the chemical shifts δ Cs of the solvated cesium ions, [16] are indicative of the presence of several types of π-complexed Cs + ions, as was observed by X-ray diffraction in the solid state (Figure 2), and their fast exchange on the NMR timescale. The broadness and significant up-field shift, compared to the chemical shifts δ Cs of the solvated cesium ions, [16] are indicative of the presence of several types of π-complexed Cs + ions, as was observed by X-ray diffraction in the solid state (Figure 2), and their fast exchange on the NMR timescale.…”

“…The 133 Cs NMR spectrum of Rub 2– /2Cs + has one broad resonance at δ Cs = –70 ppm at 20 °C, which is slightly low‐field‐shifted (Δ δ = 10 ppm) upon cooling to –80 °C [Figure 6 (c)]. The broadness and significant up‐field shift, compared to the chemical shifts δ Cs of the solvated cesium ions,16 are indicative of the presence of several types of π‐complexed Cs + ions, as was observed by X‐ray diffraction in the solid state (Figure 2), and their fast exchange on the NMR timescale.…”

Alkali Metal Complexes of a Bis(diphenylphosphino)methane Functionalized Amidinate Ligand: Synthesis and Luminescence

“…The Cs−P distance of 3.7753(9) Å is slightly longer than previously reported Cs−P contacts, for example in comparable Cs phosphide or phosphinomethanide complexes (Cs−P separations of 3.52‐3.64 Å). [ 34 , 35 , 36 , 37 ] Organometallic caesium complexes have a tendency to form coordination oligomers and polymers in the solid state, such as infinite chains or three‐dimensional networks,[ 38 , 39 , 40 , 41 , 42 ] featuring unique coordination motifs. This characteristic, amongst others, is often caused by intermolecular caesium‐π‐arene interactions.…”

Alkali Metal Yttrium neo‐Pentoxide Double Alkoxide Precursors to Alkali Metal Yttrium Oxide Nanomaterials

“…The Y‐ONep distance was 2.11 Å and the Cs‐(η‐tol) interaction was on average 3.77 Å. Again, [Cs(OAr)] n and [Y(μ‐ONep) 2 (ONep)] 4 were used for gross comparisons. The Y‐ONep and Y‐μ‐ONep distances of the model compounds were found to be 2.04 and 2.24 Å, respectively and in‐line with those noted for 5 .…”