Infrared absorption spectra of metal-amino acid complexes—VI. The infrared spectra and normal vibrations of metal-alanine chelates

Jackovitz, John F.; Durkin, J.A.; Walter, J. L.

doi:10.1016/0584-8539(67)80209-5

Cited by 54 publications

(7 citation statements)

References 22 publications

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“…The metalnitrogen bond strengths of the rest of the metals roughly follow the Irving-Williams hydrolytic stability order, previously discussed. Similar observations can be drawn from the orders of the carboxylate antisymmetric and symmetric stretching frequencies for metal complexes of the amino acid chelates of glycine [12], e-alanine [13], leucine [14] and norvaline [15]. The COO-antisymmetric stretching frequencies decrease, and the COO-symmetric stretching frequencies increase in the order Pt, Pd, Cu, Zn, Ni, Co and Cd.…”

Section: Resultssupporting

confidence: 67%

Thermogravimetric study of some divalent transition metal chelates of several amino acids

Bottei

Schneggenburger

1970

Journal of Thermal Analysis

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Thermogravimetric studies of divalent metal chelates of eight common amino acids have revealed that no relationship exists between thermal stability orders of the chelates and hydrolytic stability orders, infrared band shifts or force constants. An attempt is made to relate thermal stability order to relative heats of formation and stereochemistry.Amino acid chelates have been studied extensively during the last two decades. A variety of instrumental techniques have been used. Their thermal stabilities, however, have not been studied in any detail.Most thermal stability work has been directed at the amino acids themselves, determining decomposition temperatures [1--3] and products of decomposition [4,5]. Differential thermal analysis curves for copper glycinate mono-and dihydrate [6], cadmium glycinate monohydrate [7] and copper alaninate monohydrate [8] have been published, along with thermogravimetric curves for copper complexes of glycine and ~-alanine [9] and cobalt(III) complexes of glycine, e-alanine and leucine [10]. It has been noted [2] that aliphatic amino acids are more stable when they have short, linear alkyl side chains rather than long branched chains. Other than this, however, no attempt has been made to correlate thermal stabilities with other structural or chemical properties.Since a number of amino acid chelates were still easily available to us, it was decided to study the thermal properties of the compounds. Accordingly, thermogravimetric data for divalent transition metal chelates of glycine, DL-~-alanine, DL-fl-alanine, DL-serine, DL-c~-amino-n-butyric acid, DL-~-aminoisobutyric acid, DL-norvaline and DL-leucine were obtained. The resulting thermal data might then be compared with other available information such as infrared data and hydrolytic stability constants of amino acid chelates and thermal stabilities of other complexes of these transition metals.

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Section: Resultssupporting

confidence: 67%

Thermogravimetric study of some divalent transition metal chelates of several amino acids

Bottei

Schneggenburger

1970

Journal of Thermal Analysis

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“…(2) exhibited astrong band at (3452)cm -1 assigned to the υ(N-H), while another strong absorption band at (1718)cm -1 appeared could be explained as (OCO -)asym were the (OCO -)sym was noticed at (1355)cm -1 [7][8]. Table (2) exhibited a marked difference between bands of the stretching vibrating of υ(N-H) of( the amino group) in the range between (3105-3352)cm -1 shifted to a lower position by (347-100)cm -1 [9][10] suggesting the possibility of the coordination of ligandthrough the nitrogen atom at the amine group [11]. Absorption assigned for υ(OCO -)sym was noticed at the range (1381-1440)cm -1 shifted to higher frequencies by (85-26)cm -1 while the band caused by υ(OCO -)asym appeared between (1622-1550)cm -1 shifted to lower frequencies by (96-168)cm -1 which indicates the coordination of the carboxylic group to the central metal ion [12] the stretching vibration bands υ(C=S) and υ(C=O) carbonyl group either show no change or very little in their frequencies therefore indicating do not coordinate to the metal ion [13].…”

Section: Infrared Spectramentioning

confidence: 99%

“…-[Cu(ATG)2] d 9 The spectrum of the green showed two absorptions at(30581)cm -1 and (14450)cm -1 attributed to (C.T.) [19][20] and 2 T2→ 2 E transitions respectively.…”

Section: Electronic Spectramentioning

confidence: 99%

Synthesis and Characterization of New Metal Complexes of [N-acetyl (amino)thioxo methyl] Glycine

Naema¹

2017

JNUS

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A new Ligand (ATG)(N-acetyl amino thioxomethyl) Glycine was prepared by the reaction of acetyl iso thiocyanate with Glycine, The Ligand was characterized by FT-IR, UV-vis and 1 HNMR, some complexes of the ligand were synthesized and characterized by FT-IR, UV-vis spectra, move over determination of metal content by Flame atomic absorption spectroscopy, molar conductance in DMSO solution and magnetic moments(μeff).

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“…The bases for enantiomeric resolution are, principally, the differences in lability of the pseudo-homochiral and pseudo-heterochiral complexes that can (although not always) result in different interactions with the stationary phase and hence different chromatographic retentivities. It is worth pointing out that the complexes shown in the present work were considered to be trans, based on the work of Jackovitz et al 27 and Jackovitz and Walter, 28 who isolated similar complexes and, based on their infrared spectra and symmetry considerations, stated their stereochemistry as trans.…”

Section: Retentivity and Enantioselectivity Obtained For Racemates Usmentioning

confidence: 99%

Chiral Ligand Exchange Chromatography: Separation of Enantiomeric Mixtures of Underivatized α-Amino Acids under UV Detection

Nazareth¹,

Antunes²

2002

J. Braz. Chem. Soc.

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) em água ou em água/ metanol. A utilização de água/metanol leva a uma grande diminuição dos tempos de retenção dos α-amino ácidos mais hidrofóbicos, preservando a separação enantiomérica. O pH precisa ser alto o bastante para permitir a presença de grupos -NH 2 livres, o que torna a complexação com Cu(II) mais fácil. α-Amino ácidos conformacionalmente mais restritos, como a L-prolina e a L-hidroxiprolina, conduziram a separações enantioméricas menores. A formação de complexos pseudo-homoquirais e pseudo-heteroquirais, por troca de ligantes, que é cinética e termodinamicamente controlada, desempenha um papel fundamental para a separação enantiomérica desejada. Esta metodologia simples e barata pode ser usada em qualquer laboratório envolvido em síntese de α-amino ácidos.Enantiomeric mixtures of alanine, serine, threonine, valine, methionine, leucine and norleucine were resolved in ligand exchange reversed phase HPLC (reproducibly), by using L-proline, L-) and Cu(CH 3 COO) 2 (1 mmol L -1 ) in water or in water/methanol. The latter mobile phase greatly decreased the retention time of the more hydrophobic α-amino acids, preserving enantioseparation. pH must be high enough to allow the presence of free -NH 2 groups in order to make the complexation with Cu(II) easier. The more restricted conformation of L-proline and L-hydroxyproline led to lower enantioseparations. The ligand exchange formation of pseudo-homochiral and pseudo-heterochiral complexes, thermodynamically and kinetically controlled, plays a fundamental role for the desired enantiomeric chromatographic separation. This simple and inexpensive methodology can be used routinely by any laboratory involved in α-amino acid synthesis.

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Infrared absorption spectra of metal-amino acid complexes—VI. The infrared spectra and normal vibrations of metal-alanine chelates

Cited by 54 publications

References 22 publications

Thermogravimetric study of some divalent transition metal chelates of several amino acids

Thermogravimetric study of some divalent transition metal chelates of several amino acids

Synthesis and Characterization of New Metal Complexes of [N-acetyl (amino)thioxo methyl] Glycine

Chiral Ligand Exchange Chromatography: Separation of Enantiomeric Mixtures of Underivatized α-Amino Acids under UV Detection

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