Hi, Ulrike!

Methionine complex: Inorg. Chem., 1978, 17 (1), 34–40

DL-aspartate complex: could not find a DL one, but a catena-((μ2-L-Aspartato)-diaqua-copper(ii)) is found in Inorg. Chem. 1993, 32, 6016-6022.

Alanine complex: Inorg. Chim. Acta (1999), 288 (1), 29-34.

I am sure there are other ways of preparing the above complexes - I just took the first one I encountered.

Good luck!

regards,

Daniel

Mr. Zanzen,

You could apply the following conditions in order to receive CuII-complexes, particularly with the amino acids.

1. You should use as astarting salt CuCl2, usually it has yielded to complexes in higher amount, than starting with CuSO4, Cu(NO3)2, Cu(CH3COO)2 salts and related. The mean reason is the competitive complexation of the ligands from the last 3 salts.

2. You should operate at pH = 10 and higher, following the order: mixting of the amino acid and the Cu-salt and than adding of the solution of NaOH. At pH lower than 5 you have obtained CuCl42- containing complex salts

3. It is better to operate in CH3OH, CH3CN or solvent mixture CH3OH:H2O

4. The heating is almost obligatory, T = 50-100oC, t = 50 - 120 mins.

5. You should operate in excess of the ligand for example Cu:amino acid = 1:5 - 1:10, nevertheless that usually the isolated complexes have ratio M:L = 1:1 to 1:2 with chelating ligands. This factor, like the T mentioned in point 4, is important from the thermodynamics of the reaction.

Using 1-5 particularly we have single crystal study of Cu-glycine complex [ref.1] as well as series other CuII-complexes [refs. 2-5]

[1] Lamshoeft, M., Ivanova, B. Protonation and coordination ability of small peptides-theoretical and experimental approaches for elucidation, Journal of Coordination Chemistry, 64, 2011, 2419-2442

[2] Journal of Coordination Chemistry, 61, 2008, 1897-1905, Copper(II) complexes with hydroxyl-containing dipeptides glycyl- L-serine and L-seryl-L-tyrosine, Kolev, T., Koleva, B., Spiteller, M.

[3] Polyhedron, 19, 2000, 1843-1848, Complexes of Cu(II) with α-[(ethylamino)methyl]-3-hydroxy, benzenemethanol (Effortil). Crystal structure of the mononuclear Cu(II) complex with Effortil, Bontchev, P., Ivanova, B., Bontchev, R., Mehandjiev, D., Ivanov, D.

[4] Journal of Coordination Chemistry, 54, 2001, 117-127, Copper(II) complexes of 1-[O-allylphenoxy]-3-[isopropylamino]-2-propanol (Alprenolol), Bontchev, P., Ivanova, B., Bontchev, R., Mehandjiev, D.

[5] Transition Metal Chemistry, 28, 2003, 745-748, A mononuclear complex of copper(II) with a calcium channel antagonist nifedipine. Synthesis, properties, crystal structure, Bontchev, P., Mehandjiev, D., Ivanova, B., Bontchev, R.