Ligand-interchange reactions between M(iv) (M = Ti, V) oxide bis-acetylacetonates and halides of high-valent group 4 and 5 metals. A synthetic and electrochemical study

Abstract

The reactions of M′O(acac)2 [M′ = Ti, V; acac = acetylacetonato anion] with equimolar amounts of MF5 (M = Nb, Ta) in CH2Cl2 afforded Ti(acac)2F2, 1a, and [V(acac)3][MF6] (M = Nb, 4a; M = Ta, 4b), respectively. MOF3 (M = Nb, 2a; M = Ta, 2b) were co-produced from MF5/TiO(acac)2. The intermediate species [TaF4{OTi(acac)2}2][TaF6], 3, was intercepted in the course of the formation of 1a from TiO(acac)2/TaF5. NbCl5 reacted with TiO(acac)2 yielding selectively the previously reported [NbO(acac)Cl2]x, 5, and Ti2(acac)2(μ-Cl)2Cl4, 6. Complex 6 was alternatively obtained from the addition of a two-fold excess of TiCl4 to VO(acac)2. The 1:1 reactions of TiX4 (X = F, Cl) with TiO(acac)2 in dichloromethane gave Ti(acac)2X2 (X = F, 1a; X = Cl, 1b) and TiOX2 (X = F, 7a; X = Cl, 7b). The 1:1 combination of TiX4 (X = F, Cl) with VO(acac)2 led to 1a,b and VOX2 (X = F, 8a; X = Cl, 8b). The μ-oxido compounds (C6F5)3B–O–M′(acac)2 (M′ = Ti, V) underwent fragmentation by [PF6]− in chlorinated solvent, yielding POF3, 9, and [B(C6F5)3F]−, 10, according to NMR studies; 1a and V(acac)3(+), respectively, were detected as the metal-containing species. Electrochemical studies were carried out aiming at the full characterization of the products and the observation of possible degradation pathways.

NbF5–AlF3 Catalysts: Design, Synthesis, and Application in Lactic Acid Synthesis from Cellulose

“…Within group V, the oxide fluorides, MOF 3 , are intractable and have been studied very little . However, on the surface of the catalysts during the calcination on the basis of the characterization results, the formation of different oxide fluoride species, along with 6-fold coordinated Al units AlF x O 6– x , 5-fold coordinated units AlF x O 5– x , and 4-fold coordinated species AlF x O 4– x , cannot be excluded.…”

“…Within group V, the oxide fluorides, MOF 3 , are intractable and have been studied very little. 80 However, on the surface of the catalysts during the calcination on the basis of the characterization results, the formation of different oxide fluoride species, along with 6-fold coordinated Al units AlF x O 6−x , 5-fold coordinated units AlF x O 5−x , and 4-fold coordinated species The calcination of the catalytic samples influences the catalytic performances in terms of conversion, yields toward the reaction products, and carbon efficiency (E c ) (Table 4). E c expresses the overall selectivity to the desired liquid-phase products.…”

Reactivity and Cross-Reactivity in Redox Activation of the Uranyl Ion

“…In the 31 P spectrum of this mixture, a single set of resonances at δ = -34.9 ppm (JPF = 1072 Hz) can be seen corresponding to phosphoryl fluoride (OPF3), a species which also gives rise to a doublet in the 19 F spectrum of this mixture at δ = -88.5 ppm (JPF = 1072 Hz; literature reported shifts for OPF3: 31 P NMR (CDCl3) δ = -33.9 ppm, JPF = 1072 Hz and 19 F NMR (CDCl3) δ = -88.6 ppm, JPF = 1073 Hz). 39,40 Phosphoryl fluoride can form from the partial hydrolysis of PF5 which was likely generated under our https://doi.org/10.26434/chemrxiv-2024-nhgcl ORCID: https://orcid.org/0000-0003-4172-7460 Content not peer-reviewed by ChemRxiv. License: CC BY-NC-ND 4.0 conditions by BCF-induced halide abstraction from PF6and subsequent reaction with adventitious water present in the NMR solvent (halide abstraction from PF6by BCF has been reported).…”

Synthesis of α-Amino Acidato Derivatives of Niobium and Tantalum Pentahalides and Their Conversion into Iminium Salts

“…The NMR spectra of 3a (in CD 3 CN), containing [(C 6 H 5 CH 2 )­CHNH 2 ] + , exhibited the resonances due to the [CHN] unit at 10.40 ( 1 H) and 167.8 ( 13 C) ppm. The 93 Nb NMR spectrum of 2a consists of the typically sharp peak ascribable to the [NbCl 6 ] − anion, at 6.3 ppm 3b , 4 , and 5 could not be NMR-characterized due to scarce solubility.…”

“…In the framework of our interest in the chemistry of high-valent transition metal halides, herein we report the results of our synthetic, spectroscopic, crystallographic, and computational work on the reactions of MX 5 (M = Nb, Ta, X = Cl, Br) with a selection of α-amino acids, performed in dichloromethane. The formation of α-amino acidato complexes and the possible occurrence of activation processes will be discussed.…”