Synthesis, Preparation, and Characteristics of Copper (II) Glycinate

This report discusses the synthesis of Copper (II) Glycinate complexes, focusing on the conditions necessary for their preparation and characterization. The experiment explores the formation of Cu(II)-Gly complexes in alkaline solutions, examining the impact of varying Cu(II)/Gly molar ratios and pH levels on complex formation. Results indicate that complexes form in weak acidic to alkaline conditions, with specific compositions like Cu(II)-Gly2 emerging under certain molar ratios. The report also details the methods used for complex preparation, including paper electrophoresis, and provides insights into the structural characteristics of the synthesized complexes. The shift in absorption peaks upon glycine addition to CuSO4 confirms complex formation, with absorbance intensifying in alkaline solutions. The findings contribute to understanding the kinetic and thermodynamic aspects of copper glycine complex formation.

Running Head: SYNTHESIS OF COPPER (ii) GLYCINATE 1
Synthesis of Copper (ii) Glycinate
Name:
Institution:

Synthesis of Copper (ii) Glycinate 2
Abstract
The complexes formation mean that electrophoretic analysis may get used in examining
the Cu(ii)-Gly complex which got formed in an alkaline solution. Furthermore, the experiment
indicates that the different composition of Cu(ii)-Gly complexes got developed in the reaction
systems due to the various Cu(ii)/Gly molar ratios. Hence, a Cu(ii)-Gly2 or a [Cu(ii)-Gly]+
complex got formed in the reaction system with a (1:1) molar ratio of Cu(ii)/Gly or a less molar
ratio than 1:2 (Cu(ii)-Gly2). Furthermore, there were no complexes that got formed in strongly
acidic solutions (below pH 2) thus, weak acidic solutions (pH 3 to 7) or alkaline solutions
provided suitable conditions for the formation of complexes. Also, the structure of complexes
got examined in the article which shows a crystal structure.

Synthesis of Copper (ii) Glycinate 3
Introduction
According to Adamu et al. (2014, p.8), the coordination of chemistry deals with mostly
compounds that get formed due to coordinate bonds that get formed between central metal ions
or atoms and the coordinating ligand. Furthermore, the central atom or ion is often a transition
element while the ligand is commonly any neutral, charged ion or molecule. Thus, most of the
time the ion occasionally possesses a minimum of a lone electron pair. Moreover, the glycine can
also get referred to as the amino acetic acid which is a sweet tasting, colorless and crystalline
solid (Adamu et al., 2014, p.8). Hence, the molecular formula of glycine is C2H5NO2 which has a
molar mass of 75.07 mol-1. Also, the glycine has essential properties such as biosynthetic
intermediate which acts as a neurotransmitter. Moreover, the transition elements tend to form
coordination compounds with ligands due to them having small ionic or atomic sizes which may
have high charge or show the high state of oxidation. Hence, their oxidation state is due to the
linear increase in the transition elements which results in the increased ionization through the
molecules. Therefore, this study aims to understand synthesizes of copper (ii) complex using the
glycine as the ligand which will facilitate the preparation of both the copper glycine complexes.
Also, the analysis of the compounds will help in understanding the complex kinetic products and
which compound is a thermodynamic product (CopperGlycine, n.d, p.1).
Results
1. Formation of Cu (ii)-Gly Complex
It was essential to determine the relation between the pH values of the reaction systems and the
Cu(ii) and Gly molar ratios because it would help to understand the determine the conditions that
are necessary for the preparation of Cu(ii)-Gly complex (Imamura et al., 1978, p.36).

Synthesis of Copper (ii) Glycinate 4
Furthermore, the reaction systems were composed of around 20 types where five solutions with
different Gly and Cu(ii) ratios. These ratios were Cu(ii)/Gly= 1:3, 1:1, 1:5, 1:10 and 1:7 which
got prepared and each of them got adjusted to pH of 2.7, 7.2, 4.5 and 11. Furthermore, the
absorption of these solutions got determined after waiting for 30 minutes at 18 plus or minus 0.5
C0. In the experiment, a controlled spectrum of CuSO4 solution (Gly alone) got used, and the
absorption was noted at 210 nm while the most acidic solution which was at pH 2.7 had a similar
uptake as CuSO4. Therefore, when the pH of the solutions got made a little bit acidic (pH 4.5),
the maximum peak shifted to a small peak at 230 nm. Thus, the peak became higher with the
increase in the pH of the solution which determined the Cu(ii)-Gly complex formation in the
reaction system. These results are therefore crucial in determining the structure of the Cu(ii)-Gly
complex solution. Moreover, the elapse time effect got examined with the (1:3) Cu(ii)-Gly
system for 10 minutes just 24 hours after preparing the system. Hence, the results indicate that
the Cu(ii)-Gly complex formation took place within 10 minutes.
2. Cu(ii)-Gly Complexes Preparation
From the above results, it can get identified that the method that got used in the preparation of
Cu(ii)-Gly complex (1:2) got done using the technique on figure 1. The technique used to obtain
the complex solution got determined by the paper electrophoresis as shown in figure 2.
3. Characteristics of the Cu(ii)-Gly Complex
The contents of the glycine ad copper got prepared in this experiment using 22.9g and 53.5g per
100 g respectively which means that when the two get converted to their molar ratio the Cu(ii)-
Gly ratio became 1:2.

Synthesis of Copper (ii) Glycinate 5
Figure 1.
Figure 2.

Synthesis of Copper (ii) Glycinate 6
Conclusion
According to Imamura et al. (1978, p.40), the method that got used in the preparation of
Cu(ii)-Gly complex got determined on the examinations made on the complex formation.
Furthermore, the preparation that got obtained got resolved by the paper electrophoresis because
the Cu(ii)-Gly complex was expected to compose Cu(ii) and Gly in the molar ratio (1:2).
Discussion
From the results obtained, the glycine got added to the CuSO4 alone which resulted in the
shift in the absorption maximum from 210 nm to 230 nm which indicates the Cu(ii)-Gly complex
formation in the system. Hence, the absorbance (230nm) became more intense with the increase
in the solution pH which means that the Gly ionic state in the alkaline solution was suitable for
the complex formation. Moreover, though the absorption peak (230nm) was small in a less acidic
solution (pH 4.5), it became more significant due to the increase in the Gly concentration
reacting in the system. Therefore, the complex can get formed even in a small amount when
acidic conditions are below the Gly iso-electric point. Furthermore, when the Cu(ii) to Gly molar
ratio is 1:2 means that molar ratio of Cu(ii)/Gly to be (1:1) the aggregate amount formed was
one-half that developed in other systems. Hence, the amount of glycine added was too little
compared with the Cu(ii) in the system which is also clearly shown by figure 1 during the Cu(ii)-
Gly complex formation (1:2) (Imamura et al., 1978, p.40). Moreover, during the examination of
the pH effect formed by Cu(ii)-Gly complexes during paper electrophoresis showed that the
Cu(ii)-Gly complex got proved by a pH ranging from 9.34 to 10.40. From the experiment, the
electrophoresis indicates a pH of 8.1 which means that further use of high-voltage paper
electrophoretic is required to provide positive charges on the Cu(ii)-Gly complex.

Synthesis of Copper (ii) Glycinate 7
References
Adamu, H., Imam, M.M. and Lawal, AO (2014) Synthesis and Characterization of Copper (II)
Complex of Glycine. Nigerian Journal of Chemical Research, 19(1), pp.8-11.
CopperGlycine, (n.d) Preparation of Copper Glycine Complexes. Retrieved from:
http://webs.wofford.edu/hilljb/Chem%20323/CopperGlycine.pdf (Accessed 24 July 2018).
Imamura, T., Hatanaka, C. and Doudou, T (1978) Preparation of Copper (II)-Glycine Complex.
Department of Food Chemistry and Technology, Faculty of Fisheries and Animal Husbandry,
Hiroshima University, Fukuyama. Retrieved from:
https://ir.lib.hiroshima-u.ac.jp/files/public/4/41300/20161011103056362719/
JFacFishAnim_17_35.pdf (Accessed 24 July 2018).