Solid state 13 C-NMR, infrared, X-ray powder diffraction and differential thermal studies of the homologous series of some mono-valent metal (Li, Na, K, Ag) n -alkanoates: A comparative study

Nelson, Peter N.; Ellis, Henry A.; White, Nicole A.S.

doi:10.1016/j.saa.2015.02.101

Cited by 10 publications

(25 citation statements)

References 56 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Based on recent powder XRD studies of the homologous series of metal n -alkanoates which revealed that the silver atoms form symmetric dimers in an eight-membered ring (Aret et al 2006; Tolochko et al 1998), we propose to correlate the observed stretching separation Δν for AgL with bridging bidentate coordination (Scheme 1). According to previous correlation (Nelson et al 2015), the frequency difference below 110 cm −1 would have suggested a dimeric monodentate coordination mode for silver carboxylates. The opposite effect was observed for (bis)amine-silver carboxylate complex.…”

Section: Resultsmentioning

confidence: 73%

“…The opposite effect was observed for (bis)amine-silver carboxylate complex. Due to coordination of two amine ligands to silver ion, carboxylate group is slightly separated and becomes more ionic similarly to highly electropositive sodium carboxylate (Δν = 135 cm −1 ) (Nelson et al 2015; Wulandari et al 2015). The larger band shift for the complex with amine suggests chelating character of coordination (Scheme 1).…”

Section: Resultsmentioning

confidence: 99%

See 1 more Smart Citation

Synthesis and characterization of silver nanoparticles from (bis)alkylamine silver carboxylate precursors

Uznański¹,

Zakrzewska²,

Favier³

et al. 2017

J Nanopart Res

View full text Add to dashboard Cite

A comparative study of amine and silver carboxylate adducts [R1COOAg-2(R2NH2)] (R1 = 1, 7, 11; R2 = 8, 12) as a key intermediate in NPs synthesis is carried out via differential scanning calorimetry, solid-state FT-infrared spectroscopy, 13C CP MAS NMR, powder X-ray diffraction and X-ray photoelectron spectroscopy, and various solution NMR spectroscopies (1H and 13C NMR, pulsed field gradient spin-echo NMR, and ROESY). It is proposed that carboxyl moieties in the presence of amine ligands are bound to silver ions via chelating bidentate type of coordination as opposed to bridging bidentate coordination of pure silver carboxylates resulting from the formation of dimeric units. All complexes are packed as lamellar bilayer structures. Silver carboxylate/amine complexes show one first-order melting transition. The evidence presented in this study shows that phase behavior of monovalent metal carboxylates are controlled, mainly, by head group bonding. In solution, insoluble silver salt is stabilized by amine molecules which exist in dynamic equilibrium. Using (bis)amine-silver carboxylate complex as precursor, silver nanoparticles were fabricated. During high-temperature thermolysis, the (bis)amine-carboxylate adduct decomposes to produce silver nanoparticles of small size. NPs are stabilized by strongly interacting carboxylate and trace amounts of amine derived from the silver precursor interacting with carboxylic acid. A corresponding aliphatic amide obtained from silver precursor at high-temperature reaction conditions is not taking part in the stabilization. Combining NMR techniques with FTIR, it was possible to follow an original stabilization mechanism. Graphical abstractThe synthesis of a series (bis)alkylamine silver(I) carboxylate complexes in nonpolar solvents were carried out and fully characterized both in the solid and solution. Carboxyl moieties in the presence of amine ligands are bound to silver ions via chelating bidentate type of coordination. The complexes form layered structures which thermally decompose forming nanoparticles stabilized only by aliphatic carboxylates.

show abstract

Section: Resultsmentioning

confidence: 73%

Section: Resultsmentioning

confidence: 99%

Synthesis and characterization of silver nanoparticles from (bis)alkylamine silver carboxylate precursors

Uznański¹,

Zakrzewska²,

Favier³

et al. 2017

J Nanopart Res

View full text Add to dashboard Cite

show abstract

“…The splitting and shifting of carbon signals of COO -, CH 3 -(for [Zr(Ac) x ]) and -αCH 2 -groups (for [Zr(Oct) x ] and [Zr(Laur) x ]), as well as the decrease in their intensity, are due to a change in the electron density at these carbon atoms as a result of the coordination of carboxylate moieties to zirconium [30][31][32]. Also, conformational changes in carboxylate moieties and the formation of their nonequivalence due to different interactions with the metal center may be the cause of the observed splitting and shift of the carbon signals [33,34].…”

Section: Nuclear Magnetic Resonance Spectroscopymentioning

confidence: 99%

“…For example, zirconium pre-catalysts are used in many industrial processes of homogeneous ethylene oligomerization, such as Alphaselect (IFP Energies Nouvelles, Rueil-Malmaison Cedex, France), Alpha-Sablin (SABIC-Linde, Munich, Germany) and the process of Idemitsu Kosan Co. Ltd (Tokyo, Japan) [10][11][12]. The products of these processes are even-numbered LAOs with a wide distribution regarding the number of carbon atoms (from 4 to [30][31][32][33][34][35][36][37][38][39][40].…”

Section: Introductionmentioning

confidence: 99%

Electrochemical Synthesis of Zirconium Pre-Catalysts for Homogeneous Ethylene Oligomerization

et al. 2019

View full text Add to dashboard Cite

The catalytic activity of electrochemically synthesized zirconium carboxylates was studied in the process of ethylene oligomerization. Zirconium carboxylates were electrochemically synthesized directly from metallic zirconium and corresponding carboxylic acids (acetic, octanoic and lauric). A comprehensive study (element analysis, nuclear magnetic resonance (NMR) and infrared (IR) spectroscopy, powder X-ray diffraction (PXRD)) of the synthesized zirconium carboxylates showed that these species contain bidentate carboxylate moieties. It was shown that obtained zirconium carboxylates, in combination with Et 3 Al 2 Cl 3 (Al/Zr = 20), have a moderate activity of (7.6-9.9) × 10 3 mol C2H4 ·mol Zr −1 ·h −1 in terms of ethylene oligomerization (at T = 80 • C, p = 20 bar), leading to even-numbered C 4 -C 10 linear alpha-olefins.

show abstract

“…Also, since, like many amphiphilic systems, silver carboxylates exhibit various premelting phases when heated from the room temperature solid to the melt, some of which have been described as liquid crystalline [11], the effect on temperature on their lattice packing is of interest. For example, Nelson [12][13][14] and Binnemans et al [11] showed that for silver carboxylates (AgC 4 ⋅ ⋅ ⋅ C 28 ) the number of premelting phases increases with increasing chain length, the melt being at highest temperature, as is common for these compounds. However, the suggestion by Binnemans that more than one liquid crystalline phases were present in the phase sequences for some silver compounds was questioned by Nelson, based on high temperature microscopy data, but not totally ruled out.…”

Section: Introductionmentioning

confidence: 99%

Chain Length and Thermal Sensitivity of the Infrared Spectra of a Homologous Series of Anhydrous Silver(I)n-Alkanoates

Nelson

2016

International Journal of Spectroscopy

Self Cite

View full text Add to dashboard Cite

The thermal and chain length sensitivity of the infrared spectra of some solid state anhydrous silver(I) salts (n-octanoate to n-eicosanoate, inclusive) are discussed. At ambient temperature, the tilted alkyl chains, anchored to the metal planes via chelating bidentate coordination to the silver ions, are crystallized in the fully extended all-trans conformation. Interestingly, though all compounds are crystallized in a monoclinic crystal system, their lateral chain packing, van der Waals effects, and hence vibrational features are chain length-dependent. This is a direct result of electrostatic effects of the COO group in addition to vibrational coupling between CH2, CH3, and COO modes, an effect which varies significantly with chain length. Variable temperature infrared measurements indicate significant irreversible changes in the metal-carboxyl coordination sphere, most likely due to bond fission. For long chain adducts (nc>12), thermally induced crystal system switching, monoclinic to triclinic, indicates greater thermal sensitivity of their alkyl chains. During heating, the regions of the hydrocarbon chains, furthest from the COO, become increasingly molten and mobile as the stepwise melt advances towards the solid COO moieties. This solid-liquid melting behaviour is responsible for mesophase formation in metal carboxylate systems.

show abstract

Solid state 13 C-NMR, infrared, X-ray powder diffraction and differential thermal studies of the homologous series of some mono-valent metal (Li, Na, K, Ag) n -alkanoates: A comparative study

Cited by 10 publications

References 56 publications

Synthesis and characterization of silver nanoparticles from (bis)alkylamine silver carboxylate precursors

Synthesis and characterization of silver nanoparticles from (bis)alkylamine silver carboxylate precursors

Electrochemical Synthesis of Zirconium Pre-Catalysts for Homogeneous Ethylene Oligomerization

Chain Length and Thermal Sensitivity of the Infrared Spectra of a Homologous Series of Anhydrous Silver(I)n-Alkanoates

Contact Info

Product

Resources

About