Metal 2-ethylhexanoates and related compounds as useful precursors in materials science

Abstract

This critical review deals with the chemistry and applications of metal alkanoates with medium size (C5 to C12) carbon chain length. A particular emphasis is given to metal 2-ethylhexanoates, which find wide applications as metal-organic precursors in materials science, as catalysts for ring opening polymerizations and also in painting industries for their properties as driers. After a brief introduction and an overview of synthesis, structural and physico-chemical properties, this article discuses extensively the applications of these compounds in materials science. Finally, it identifies and signifies the areas for future research in the looking ahead section. The aim of this review is to bridge the areas of precursor's chemistry and materials science by providing a reference text for researchers working either in or at the interface of these two areas (125 references).

Co( iii ) 2-ethylhexanoate, a hydrophobic and highly soluble Co( iii ) precursor for thin coatings for water electrolysis

“…The free ligand, 2-eh, appears remarkably less stable against thermal degradation than when it is involved in either the Co( ii )eh or Co( iii )eh complexes, showing a 95% weight loss at 180 °C, while Co( ii )eh and Co( iii )eh convert to metallic cobalt at 350 °C. In agreement with what was reported for other metal 2-ethylhexanoates, 17,22,34,35 both Co( iii )eh and Co( iii )eh decompose in two stages: a first partial degradation step occurs between 150 and 220 °C (see also Fig. S6a, ESI†), followed by quick and complete decomposition between 300 and 350 °C.…”

“…The turbid suspensions of Co(III)eh in amines After evaporation of the solvent, Co(III)eh solutions leave a dark green-brown viscous residue, as expected because the asymmetric branched 2-ethylhexanoate chains favor disorder and prevent the formation of crystalline phases. 17 The absence of crystallization is also shown by the differential scanning calorimetry results (Fig. S6, ESI †).…”

Co( iii ) 2-ethylhexanoate, a hydrophobic and highly soluble Co( iii ) precursor for thin coatings for water electrolysis

“…The free ligand, 2-eh, appears remarkably less stable against thermal degradation than when it is involved in either the Co( ii )eh or Co( iii )eh complexes, showing a 95% weight loss at 180 °C, while Co( ii )eh and Co( iii )eh convert to metallic cobalt at 350 °C. In agreement with what was reported for other metal 2-ethylhexanoates, 17,22,34,35 both Co( iii )eh and Co( iii )eh decompose in two stages: a first partial degradation step occurs between 150 and 220 °C (see also Fig. S6a, ESI†), followed by quick and complete decomposition between 300 and 350 °C.…”

“…The turbid suspensions of Co(III)eh in amines After evaporation of the solvent, Co(III)eh solutions leave a dark green-brown viscous residue, as expected because the asymmetric branched 2-ethylhexanoate chains favor disorder and prevent the formation of crystalline phases. 17 The absence of crystallization is also shown by the differential scanning calorimetry results (Fig. S6, ESI †).…”

The role of microexplosions in flame spray synthesis for homogeneous nanopowders from low‐cost metal precursors

“…These decomposition steps can be attributed to carboxylate complexes, formed by the 2‐ethylhexanoic acid and the metal ions in the solutions, as suggested by Strobel and Pratsinis . Metal carboxylates typically decompose in a two‐ or three‐step process to the metal oxides, as observed also for Zn‐naphthenate (Figure ). The residual masses of 3.5 and 2.9 wt % for the Fe‐ and Al‐nitrate solutions agree well with the expected 4.0 and 2.6 wt % of Fe 2 O 3 and Al 2 O 3 , respectively.…”

Comparison and Functionalization Study of Microemulsion-Prepared Magnetic Iron Oxide Nanoparticles

“…However, the chemistry of metal 2-ethylhexanoates is still largely unexplored; typically, reaction mechanisms involve either thermal decomposition or photolysis. 22 However, neither of these conditions is provided in the present method, and we may postulate that the reaction in Scheme 2 takes place.…”

Co( iii ) 2-ethylhexanoate, a hydrophobic and highly soluble Co( iii ) precursor for thin coatings for water electrolysis

“…The free ligand, 2-eh, appears remarkably less stable against thermal degradation than when it is involved in either the Co( ii )eh or Co( iii )eh complexes, showing a 95% weight loss at 180 °C, while Co( ii )eh and Co( iii )eh convert to metallic cobalt at 350 °C. In agreement with what was reported for other metal 2-ethylhexanoates, 17,22,34,35 both Co( iii )eh and Co( iii )eh decompose in two stages: a first partial degradation step occurs between 150 and 220 °C (see also Fig. S6a, ESI†), followed by quick and complete decomposition between 300 and 350 °C.…”

“…The turbid suspensions of Co(III)eh in amines After evaporation of the solvent, Co(III)eh solutions leave a dark green-brown viscous residue, as expected because the asymmetric branched 2-ethylhexanoate chains favor disorder and prevent the formation of crystalline phases. 17 The absence of crystallization is also shown by the differential scanning calorimetry results (Fig. S6, ESI †).…”

The role of microexplosions in flame spray synthesis for homogeneous nanopowders from low‐cost metal precursors

“…These decomposition steps can be attributed to carboxylate complexes, formed by the 2‐ethylhexanoic acid and the metal ions in the solutions, as suggested by Strobel and Pratsinis . Metal carboxylates typically decompose in a two‐ or three‐step process to the metal oxides, as observed also for Zn‐naphthenate (Figure ). The residual masses of 3.5 and 2.9 wt % for the Fe‐ and Al‐nitrate solutions agree well with the expected 4.0 and 2.6 wt % of Fe 2 O 3 and Al 2 O 3 , respectively.…”

Comparison and Functionalization Study of Microemulsion-Prepared Magnetic Iron Oxide Nanoparticles

“…However, the chemistry of metal 2-ethylhexanoates is still largely unexplored; typically, reaction mechanisms involve either thermal decomposition or photolysis. 22 However, neither of these conditions is provided in the present method, and we may postulate that the reaction in Scheme 2 takes place.…”

Co( iii ) 2-ethylhexanoate, a hydrophobic and highly soluble Co( iii ) precursor for thin coatings for water electrolysis

“…The free ligand, 2-eh, appears remarkably less stable against thermal degradation than when it is involved in either the Co( ii )eh or Co( iii )eh complexes, showing a 95% weight loss at 180 °C, while Co( ii )eh and Co( iii )eh convert to metallic cobalt at 350 °C. In agreement with what was reported for other metal 2-ethylhexanoates, 17,22,34,35 both Co( iii )eh and Co( iii )eh decompose in two stages: a first partial degradation step occurs between 150 and 220 °C (see also Fig. S6a, ESI†), followed by quick and complete decomposition between 300 and 350 °C.…”

“…The turbid suspensions of Co(III)eh in amines After evaporation of the solvent, Co(III)eh solutions leave a dark green-brown viscous residue, as expected because the asymmetric branched 2-ethylhexanoate chains favor disorder and prevent the formation of crystalline phases. 17 The absence of crystallization is also shown by the differential scanning calorimetry results (Fig. S6, ESI †).…”

The role of microexplosions in flame spray synthesis for homogeneous nanopowders from low‐cost metal precursors

“…These decomposition steps can be attributed to carboxylate complexes, formed by the 2‐ethylhexanoic acid and the metal ions in the solutions, as suggested by Strobel and Pratsinis . Metal carboxylates typically decompose in a two‐ or three‐step process to the metal oxides, as observed also for Zn‐naphthenate (Figure ). The residual masses of 3.5 and 2.9 wt % for the Fe‐ and Al‐nitrate solutions agree well with the expected 4.0 and 2.6 wt % of Fe 2 O 3 and Al 2 O 3 , respectively.…”

Comparison and Functionalization Study of Microemulsion-Prepared Magnetic Iron Oxide Nanoparticles

“…However, the chemistry of metal 2-ethylhexanoates is still largely unexplored; typically, reaction mechanisms involve either thermal decomposition or photolysis. 22 However, neither of these conditions is provided in the present method, and we may postulate that the reaction in Scheme 2 takes place.…”