941-02-6Relevant academic research and scientific papers
Molecular structures of triethylamine complexes with benzoic and pivalic acids
Yakovleva,Perova,Kislina,Librovich,Nefedov
, p. 1228 - 1233 (2010)
Dissolution of benzoic or pivalic acid in excess triethylamine followed by crystallization was found to yield single crystals of 1 : 1 and 1 : 2 complexes, respectively. X-ray crystallography have shown that the complex with benzoic acid is an (Et3/
METHODS OF RING OPENING POLYMERIZATION AND CATALYSTS THEREFOR
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Page/Page column 15-16, (2012/03/10)
A salt catalyst comprises an ionic complex of i) a nitrogen base comprising one or more guanidine and/or amidine functional groups, and ii) an oxoacid comprising one or more active acid groups, the active acid groups independently comprising a carbonyl group (C═O), sulfoxide group (S═O), and/or a phosphonyl group (P═O) bonded to one or more active hydroxy groups; wherein a ratio of moles of the active hydroxy groups to moles of the guanidine and/or amidine functional groups is greater than 0 and less than 2.0. The salt catalysts are capable of catalyzing ring opening polymerization of cyclic carbonyl compounds.
Mechanistic studies of the O2-dependent aliphatic carbon-carbon bond cleavage reaction of a nickel enolate complex
Berreau, Lisa M.,Borowski, Tomasz,Grubel, Katarzyna,Allpress, Caleb J.,Wikstrom, Jeffrey P.,Germain, Meaghan E.,Rybak-Akimova, Elena V.,Tierney, David L.
experimental part, p. 1047 - 1057 (2011/05/05)
The mononuclear nickel(II) enolate complex [(6-Ph2TPA)Ni(PhC(O)C(OH)C(O)Ph] ClO4 (I) was the first reactive model complex for the enzyme/substrate (ES) adduct in nickel(II)-containing acireductone dioxygenases (ARDs) to be reported. In this contribution, the mechanism of its O 2-dependent aliphatic carbon-carbon bond cleavage reactivity was further investigated. Stopped-flow kinetic studies revealed that the reaction of I with O2 is second-order overall and is ～ 80 times slower at 25 °C than the reaction involving the enolate salt [Me4N][PhC(O) C(OH)C(O)Ph]. Computational studies of the reaction of the anion [PhC(O)C(OH)C(O)Ph]- with O2 support a hydroperoxide mechanism wherein the first step is a redox process that results in the formation of 1,3-diphenylpropanetrione and HOO-. Independent experiments indicate that the reaction between 1,3-diphenylpropanetrione and HOO- results in oxidative aliphatic carbon-carbon bond cleavage and the formation of benzoic acid, benzoate, and CO:CO2 ( ～ 12:1). Experiments in the presence of a nickel(II) complex gave a similar product distribution, albeit benzil [PhC(O)C(O)Ph] is also formed, and the CO:CO2 ratio is ～ 1.5:1. The results for the nickel(II)-containing reaction match those found for the reaction of I with O2 and provide support for a trione/HOO- pathway for aliphatic carbon-carbon bond cleavage. Overall, I is a reasonable structural model for the ES adduct formed in the active site of Ni"ARD. However, the presence of phenyl appendages at both C(1) and C(3) in the [PhC(O)C(OH)C(O)Ph]- anion results in a reaction pathway for O2-dependent aliphatic carbon-carbon bond cleavage (via a trione intermediate) that differs from that accessible to C(1)- H acireductone species. This study, as the first detailed investigation of the O2 reactivity of a nickel(II) enolate complex of relevance to Ni"ARD, provides insight toward understanding the chemical factors involved in the O2 reactivity of metal acireductone species.
FORMATION OF MOLECULAR COMPLEXES OF HEXAMETHYLENIMINE AND OF TRIETHYLAMINE WITH BENZOIC ACID IN BENZENE
Kartsev, G. N.,Ignat'eva, S. I.,Polteva, M. N.,Shcherbakova, E. S.
, p. 1505 - 1510 (2007/10/02)
In the systems hexamethylenimine-benzoic acid and triethylamine-benzoic acid in benzene solutions two molecular complexes with different compositions are formed in each case.The first system, unlike the second, contains a stable 2:2 complex.The complexes
