Copper(II) glycinate

Last updated
Copper(II) glycinate
Cu(gly)2(OH2).png
Structure of the cis monohydrate form of bis(glycinato)copper(II)
Names
IUPAC name
bis(glycinato)copper(II)
Other names
cupric glycinate
Identifiers
3D model (JSmol)
ChemSpider
ECHA InfoCard 100.033.425 OOjs UI icon edit-ltr-progressive.svg
EC Number
  • 236-783-2
PubChem CID
UNII
  • InChI=1S/2C2H5NO2.Cu/c2*3-1-2(4)5;/h2*1,3H2,(H,4,5);/q;;+2/p-2
    Key: VVYPIVJZLVJPGU-UHFFFAOYSA-L
  • C(C(=O)[O-])N.C(C(=O)[O-])N.[Cu+2]
Properties
C4H10CuN2O5
Molar mass 229.679 g·mol−1
Appearancelight blue, flake-like crystals (cis form)
Density 2.029 g/cm3
Melting point 212 °C (414 °F; 485 K) (decomp.)
0.18 g/100 g (0 °C)
0.52 g/100 g (25 °C)
Solubility soluble in DMF, DMSO, pyridine; slightly soluble in ethanol
Structure [1]
Orthorhombic
№ 19 (P212121)
222
a = 5.21 Å, b = 10.81 Å, c = 13.49 Å
4
Hazards
GHS labelling:
GHS-pictogram-exclam.svg GHS-pictogram-pollu.svg
Warning
H302, H315, H319, H400
P264, P270, P273, P280, P301+P312, P302+P352, P305+P351+P338, P321, P330, P332+P313, P337+P313, P362, P391, P501
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).

Copper(II) glycinate (IUPAC suggested name: bis(glycinato)copper(II)) refers to the coordination complex of copper(II) with two equivalents of glycinate, with the formula [Cu(glycinate)2(H2O)x] where x = 1 (monohydrate) or 0 (anhydrous form). The complex was first reported in 1841, and its chemistry has been revisited many times, particularly in relation to the isomerisation reaction between the cis and trans forms which was first reported in 1890. [2] [3]

Contents

All forms are blue solids, with varying degrees of water solubility. A practical application of the compound is as a source of dietary copper in animal feeds. [4]

Synthesis

Bis(glycinato)copper(II) is typically prepared from the reaction of copper(II) acetate in aqueous ethanol with glycine: [2] [3]

Cu(OAc)2 + 2 H2NCH2COOH + x H2O → [Cu(H2NCH2COO)2(H2O)x] + 2 AcOH, x = 0 or 1

The reaction proceeds through a non-redox dissociative substitution mechanism and usually affords the cis isomer. [2] [3]

Structure

Like most amino acid complexes, the glycinate forms a 5-membered chelate ring, with the glycinato ligand serving as a bidentate (κ2Ο,Ν) species. [2] [5] The chelating ligands assume a square planar configuration around the copper atom as is common for tetracoordinate d9 complexes, calculated to be much lower in energy than the alternative tetrahedral arrangement. [3]

Cis and trans isomerism

The unsymmetric nature of the ligand and square planar coordination thereof gives rise to two possible geometric isomers: a cis and a trans form.

Multiple ways of differentiating the geometric isomers exist, an easily accessible one being IR spectroscopy with the characteristic number of C–N, C–O, and CuII–N identifying the ligand configuration. Crystal appearance may also be of some value for isomer indication, though the ultimate diagnostic technique is X-ray crystallography. [1]

All forms of the complex have been characterized crystallographically, the most commonly isolated one being the cis monohydrate (x = 1). [5] [1]

Isomerisation of the cis to the trans form occurs at high temperatures via a ring-twisting mechanism. [2] [3]

Related Research Articles

<span class="mw-page-title-main">Coordination complex</span> Molecule or ion containing ligands datively bonded to a central metallic atom

A coordination complex is a chemical compound consisting of a central atom or ion, which is usually metallic and is called the coordination centre, and a surrounding array of bound molecules or ions, that are in turn known as ligands or complexing agents. Many metal-containing compounds, especially those that include transition metals, are coordination complexes.

<span class="mw-page-title-main">Peptide bond</span> Covalent chemical bond between amino acids in a peptide or protein chain

In organic chemistry, a peptide bond is an amide type of covalent chemical bond linking two consecutive alpha-amino acids from C1 of one alpha-amino acid and N2 of another, along a peptide or protein chain.

Chelation is a type of bonding of ions and their molecules to metal ions. It involves the formation or presence of two or more separate coordinate bonds between a polydentate ligand and a single central metal atom. These ligands are called chelants, chelators, chelating agents, or sequestering agents. They are usually organic compounds, but this is not a necessity.

<span class="mw-page-title-main">Copper(II) nitrate</span> Chemical compound

Copper(II) nitrate describes any member of the family of inorganic compounds with the formula Cu(NO3)2(H2O)x. The hydrates are blue solids. Anhydrous copper nitrate forms blue-green crystals and sublimes in a vacuum at 150-200 °C. Common hydrates are the hemipentahydrate and trihydrate.

<span class="mw-page-title-main">1,10-Phenanthroline</span> Heterocyclic organic compound

1,10-Phenanthroline (phen) is a heterocyclic organic compound. It is a white solid that is soluble in organic solvents. The 1,10 refer to the location of the nitrogen atoms that replace CH's in the hydrocarbon called phenanthrene.

<span class="mw-page-title-main">Metal ammine complex</span> Class of chemical compounds

In coordination chemistry, metal ammine complexes are metal complexes containing at least one ammonia ligand. "Ammine" is spelled this way for historical reasons; in contrast, alkyl or aryl bearing ligands are spelt with a single "m". Almost all metal ions bind ammonia as a ligand, but the most prevalent examples of ammine complexes are for Cr(III), Co(III), Ni(II), Cu(II) as well as several platinum group metals.

Cycloocta-1,5-diene is a cyclic hydrocarbon with the chemical formula C8H12, specifically [−(CH2)2−CH=CH−]2.

<span class="mw-page-title-main">Prolyl isomerase</span> Enzyme

Prolyl isomerase is an enzyme found in both prokaryotes and eukaryotes that interconverts the cis and trans isomers of peptide bonds with the amino acid proline. Proline has an unusually conformationally restrained peptide bond due to its cyclic structure with its side chain bonded to its secondary amine nitrogen. Most amino acids have a strong energetic preference for the trans peptide bond conformation due to steric hindrance, but proline's unusual structure stabilizes the cis form so that both isomers are populated under biologically relevant conditions. Proteins with prolyl isomerase activity include cyclophilin, FKBPs, and parvulin, although larger proteins can also contain prolyl isomerase domains.

<span class="mw-page-title-main">Nickel(II) bis(acetylacetonate)</span> Coordination complex

Nickel(II) bis(acetylacetonate) is a coordination complex with the formula [Ni(acac)2]3, where acac is the anion C5H7O2 derived from deprotonation of acetylacetone. It is a dark green paramagnetic solid that is soluble in organic solvents such as toluene. It reacts with water to give the blue-green diaquo complex Ni(acac)2(H2O)2.

Metal acetylacetonates are coordination complexes derived from the acetylacetonate anion (CH
3
COCHCOCH
3
) and metal ions, usually transition metals. The bidentate ligand acetylacetonate is often abbreviated acac. Typically both oxygen atoms bind to the metal to form a six-membered chelate ring. The simplest complexes have the formula M(acac)3 and M(acac)2. Mixed-ligand complexes, e.g. VO(acac)2, are also numerous. Variations of acetylacetonate have also been developed with myriad substituents in place of methyl (RCOCHCOR). Many such complexes are soluble in organic solvents, in contrast to the related metal halides. Because of these properties, acac complexes are sometimes used as catalyst precursors and reagents. Applications include their use as NMR "shift reagents" and as catalysts for organic synthesis, and precursors to industrial hydroformylation catalysts. C
5
H
7
O
2
in some cases also binds to metals through the central carbon atom; this bonding mode is more common for the third-row transition metals such as platinum(II) and iridium(III).

<span class="mw-page-title-main">Metal-phosphine complex</span>

A metal-phosphine complex is a coordination complex containing one or more phosphine ligands. Almost always, the phosphine is an organophosphine of the type R3P (R = alkyl, aryl). Metal phosphine complexes are useful in homogeneous catalysis. Prominent examples of metal phosphine complexes include Wilkinson's catalyst (Rh(PPh3)3Cl), Grubbs' catalyst, and tetrakis(triphenylphosphine)palladium(0).

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<span class="mw-page-title-main">Transplatin</span> Chemical compound

trans-Dichlorodiammineplatinum(II) is the trans isomer of the coordination complex with the formula trans-PtCl2(NH3)2, sometimes called transplatin. It is a yellow solid with low solubility in water but good solubility in DMF. The existence of two isomers of PtCl2(NH3)2 led Alfred Werner to propose square planar molecular geometry. It belongs to the molecular symmetry point group D2h.

<span class="mw-page-title-main">Salpn ligand</span> Chemical compound

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<span class="mw-page-title-main">Transition metal thioether complex</span>

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References

  1. 1 2 3 Köse, Dursun Ali; Toprak, Emre; Kaşarcı, Aliye; Avcı, Emre; Avcı, Gülçin Alp; Şahin, Onur; Büyükgüngör, Orhan (2016-07-02). "Synthesis, Spectral, and Thermal Studies of Co(II), Ni(II), Cu(II), and Zn(II)-Glycinato Complexes and Investigation of Their Biological Properties: Crystal Structure of [Cu(µ-gly) 2 (H 2 O)] n". Synthesis and Reactivity in Inorganic, Metal-Organic, and Nano-Metal Chemistry. 46 (7): 1109–1118. doi:10.1080/15533174.2013.801855. ISSN   1553-3174. S2CID   101548954.
  2. 1 2 3 4 5 Delf, B. W.; Gillard, R. D.; O'Brien, P. (1979-01-01). "The isomers of α-amino-acids with copper(II). Part 5. The cis and trans isomers of bis(glycinato)copper(II), and their novel thermal isomerization". Journal of the Chemical Society, Dalton Transactions (8): 1301–1305. doi:10.1039/DT9790001301. ISSN   1364-5447.
  3. 1 2 3 4 5 Tautermann, Christofer S.; Sabolović, Jasmina; Voegele, Andreas F.; Liedl, Klaus R. (2004-02-01). "Mechanism of the Cis−Trans Isomerization of Bis(glycinato)copper(II)". The Journal of Physical Chemistry B. 108 (6): 2098–2102. doi:10.1021/jp0364497. ISSN   1520-6106.
  4. Ward, J. D.; Spears, J. W. (1997). "Long-Term Effects of Consumption of Low-Copper Diets with or Without Supplemental Molybdenum on Copper Status, Performance, and Carcass Characteristics of Cattle". Journal of Animal Science. 75 (11): 3057–3065. doi: 10.2527/1997.75113057x . PMID   9374323.
  5. 1 2 Casari, B. M.; Mahmoudkhani, A. H.; Langer, V. (2004). "A Redetermination of cis-Aquabis(glycinato-κ2N,O)copper(II)". Acta Crystallogr. E. 60 (12): m1949–m1951. doi:10.1107/S1600536804030041.