Characterization of Co(II)-PAMAM dendrimer complexes with polypropylene oxide core by using UV-VIS spectroscopy

Ali Serol Ertürk, Mustafa Ulvi Gürbüz, Metin Tülü, Abdürrezzak Emin Bozdoğan


The aim of this study was to characterize poly(amidoamine) (PAMAM) dendrimer complexes of Co(II) ions by using UV-Vis spectroscopy. For this aim, a generation-4 polypropylene oxide (Jeffamine® T-403) cored and amine-terminated PAMAM dendrimer (P4) was used as a model complexation agent. Optimum complexation condition for P4 was determined by potentiometric and spectroscopic titration studies. Extent of protonation (EOP) of the amino groups of P4 was determined from the potentiometric titration data and validated with spectroscopic titration data. The results indicated that pH 8 was the optimum dendrimer aqueous solution media, where the available number of tertiary amines present in P4 was the highest for possible metal complexation. At the optimized conditions, UV-Vis characterization of the Co(II)-P4 complexes was performed and 585–635 nm d-d transition bands were observed as the characteristic complexation bands of the tertiary amine groups of P4 with Co(II) ions. Obtained Co(II)-P4 complexes might be considered for the development of magnetic resonance image (MRI) improvers or MRI contrast agents.


PAMAM dendrimer; Jeffamine; complexation; UV-VIS spectroscopy; MRI contrast agents

Full Text:



J. H. Kim, H. J. Gibb, P. D. Howe, M. Sheffer, U. N. E. Programme, I. L. Organisation, W. H. Organization, I.-O.P.f.t.S.M.o. Chemicals, Cobalt and Inorganic Cobalt Compounds, World Health Organization (2006).

S. E. Bailey, T. J. Olin, R. M. Bricka, D. D. Adrian, A review of potentially low-cost sorbents for heavy metals, Water Res., 33, 2469–2479 (1999).

DOI: 10.1016/s0043-1354(98)00475-8.

A. Kabata-Pendias, Trace Elements in Soils and Plants, Third Edition, Taylor & Francis, (2010).

DOI: 10.1201/9781420039900.ch5.

J. G. Hengstler, U. Bolm-Audorff, A. Faldum, K. Janssen, M. Reifenrath, W. Götte, D. Jung, O. Mayer-Popken, J. Fuchs, S. Gebhard, H. G. Bienfait, K. Schlink, C. Dietrich, D. Faust, B. Epe, F. Oesch, Occupational exposure to heavy metals: DNA damage induction and DNA repair inhibition prove co-exposures to cadmium, cobalt and lead as more dangerous than hitherto expected, Carcinogenesis, 24, 63–73 (2003). DOI: 10.1093/carcin/24.1.63.

K. Yamamoto, S. Inoue, A. Yamazaki, T. Yoshinaga, S. Kawanishi, Site-specific DNA damage induced by cobalt(II) ion and hydrogen peroxide: role of singlet oxygen, Chem. Res. Toxicol., 2, 234–239 (1989).

DOI: 10.1021/tx00010a004.

A. Sigel, H. Sigel, R. K. O. Sigel, Organometallics in Environment and Toxicology, RSC Publishing, (2010). DOI: 10.1039/9781849730822..

J. F. Hainfeld, Extended organic cobalt and nickel magnetic complexes, in, Google Patents (2003).

F. Zeng, S. C. Zimmerman, Dendrimers in supra-molecular chemistry: From molecular recognition to self-assembly, Chem. Rev. (Washington, D. C.), 97, 1681–1712 (1997). DOI: 10.1021/CR9603892.

M. S. Diallo, S. Christie, P. Swaminathan, L. Balogh, X. Shi, W. Um, C. Papelis, W. A. Goddard, III, J. H. Johnson, Jr., Dendritic Chelating Agents. 1. Cu(II) Binding to Ethylene Diamine Core Poly(amidoamine) Dendrimers in Aqueous Solutions, Langmuir, 20, 2640–2651 (2004).

DOI: 10.1021/la036108k.

A. D. Schluter, J. P. Rabe, Dendronized polymers: synthesis, characterization, assembly at interfaces, and manipulation, Angew. Chem., Int. Ed., 39, 864–883 (2000). DOI: 10.1002/(SICI)1521-3773(20000303)39:5<864:: AID-ANIE864>3.0.CO;2-E.

A. S. Ertürk, M. Tülü, A. E. Bozdoğan, T. Parali, Microwave assisted synthesis of Jeffamine cored PAMAM dendrimers, Eur. Polym. J., 52, 218–226 (2014). DOI: 10.1016/j.eurpolymj.2013.12.018.

A. S. Erturk, M. U. Gurbuz, M. Tulu, A. E. Bozdogan, Water-soluble TRIS-terminated PAMAM dendrimers: microwave-assisted synthesis, characterization and Cu(ii) intradendrimer complexes, RSC Adv., 5, 60581–60595 (2015). DOI: 10.1039/C5RA11157A.

I. J. Majoros, B. Keszler, S. Woehler, T. Bull, J. R. Baker, Acetylation of Poly(amidoamine) Dendrimers, Macromolecules, 36, 5526–5529 (2003).

DOI: 10.1021/ma021540e.

I. J. Majoros, T. P. Thomas, C. B. Mehta, J. R. Baker, Poly(amidoamine) Dendrimer-Based Multifunctional Engineered Nanodevice for Cancer Therapy, J. Med. Chem., 48, 5892–5899 (2005). DOI: 10.1021/jm0401863.

D. Cakara, J. Kleimann, M. Borkovec, Microscopic Protonation Equilibria of Poly(amidoamine) Dendrimers from Macroscopic Titrations, Macromolecules, 36, 4201–4207 (2003). DOI: 10.1021/ma0300241.

Y. Niu, L. Sun, R. M. Crooks, Determination of the Intrinsic Proton Binding Constants for Poly (amidoamine) Dendrimers via Potentiometric pH Titration, Macromolecules, 36, 5725–5731 (2003).

DOI: 10.1021/ma034276d.

V. Kabanov, A. Zezin, V. Rogacheva, Z. G. Gulyaeva, M. Zansochova, J. Joosten, J. Brackman, Polyelectrolyte behavior of astramol poly(propyleneimine) dendrimers, Macromolecules, 31, 5142–5144 (1998).

DOI: 10.1021/ma971643a.

L. Sun, R. M. Crooks, Interactions between Dendrimers and Charged Probe Molecules. 1. Theoretical Methods for Simulating Proton and Metal Ion Binding to Symmetric Polydentate Ligands, J. Phys. Chem. B, 106, 5864–5872 (2002). DOI: 10.1021/jp020189w.

M. H. Kleinman, J. H. Flory, D. A. Tomalia, N. J. Turro, Effect of Protonation and PAMAM Dendrimer Size on the Complexation and Dynamic Mobility of 2-Naphthol, J. Phys. Chem. B, 104, 11472–11479 (2000).

DOI: 10.1021/jp001882r.

S. Pande, R. M. Crooks, Analysis of poly(amidoamine) dendrimer structure by UV–Vis spectroscopy, Langmuir, 27, 9609–9613 (2011).

DOI: 10.1021/la201882t.

F. A. Cotton, Advanced Inorganic Chemistry, Wiley, (1999). DOI: 10.5860/choice.37-0940.



  • There are currently no refbacks.

Copyright (c) 2016 Ali Serol Ertürk, Mustafa Ulvi Gürbüz, Metin Tülü, Abdurrezzak Emın Bozdoğan

Creative Commons License
This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License.