1. Department of Chemistry
Synthesis and Characterization of bis(2-hydroxyethyl)dithiocarbamate complexes of Zinc, Mercury, Uranium, Lead, Chromium, and Calcium
Gregory Trzcinski
Department of Chemistry
McDaniel College
February 27, 2009

2. Overview Introduction Why this ligand? Why these metals?
Facts on metals
What type of analyses?
“The Big Nine”
Syntheses
Ligand
Proposed Mechanism
Metal complexes
Self Assembly
Results/Discussion
Conclusion
Future Work
Questions?

3. Why this ligand? Increased interest
Analytical agents
Medicinal drugs
Known treatment for heavy metal and organometallic cation poisoning
Known metal binding capacities
Potassium bis(2-hydroxyethyl)dithiocarbamate

4. Why these metals? Interested in the metals
Recognized toxicity in sufficient amounts
Availability
In the environment
In reagents
More complete study of Zinc and Mercury started by Pages et al.

5. Calcium Essential Most abundant metal in the body
Body needs a constant level
Muscle contractions
Daily recommended amount ~1000mg
Excess can lead to health concerns
Decreased absorption of other metals  

6. Chromium Essential in trace amounts Adequate intake ~35μg
Found in two forms 3+, biologically active, and 6+, toxic
Few adverse effects

7. Zinc Essential Variety of cellular functions Adequate intake ~11mg
Excess can lead to health concerns
Decrease of HDL
Toxicity has led to deficiencies in other essential metals

8. Mercury Non-essential, toxic
Vaporizes at ambient temperature and pressure
Vaporized form can remain in the air for up to a year
Deposited all over the world

9. Uranium Non-essential Used in power plants
Depleted uranium most common
Byproduct
Military use
90μg is present in body
Increased use can be hazardous

10. Lead Non-essential Very toxic Typically found in paint
More readily absorbed by children
Myriad of health concerns

11. “The Big Nine” Melting Point (in Celsius) Yield (in grams)
Percent Yield
1H Nuclear Magnetic Resonance spectroscopy (NMR)
13C NMR
Infrared Spectroscopy (IR)
Ultraviolet-Visible Spectrophotometry (UV-Vis)
Mass Spectrometry (Mass Spec): Electrospray + or -
Elemental Analysis

12. What to look for and accomplish?
The presence of the metal in the resultant complexes
Theorize a structure for each complex

13. Ligand Synthesis
KOH 2. 1.
CS2
DEA 3.
K[bhedtc]

14. Proposed Mechanism

15. Complex Syntheses K[bhedtc] in H2O CaCl2 in EtOH HgCl2 in MeOH
ZnCl2 in H2O
M[bhedtc]2
M = Ca, Hg, Zn

16. Complex Syntheses K[bhedtc] in H2O UO2(OAc)2· 2H2O in H2O
Pb(OAc)2 · 3H2O in H2O
K2Cr2O7 in H2O
K[UO2(bhedtc)3]
Pb[bhedtc]2
Cr[bhedtc]3

17. Self Assembly
DEA 2. 1.
MCl2
CS2 in MeOH 3.
M[bhedtc]2
M = Hg or Zn

18. Solubility Chart

19. Data Chart

20. K[bhedtc] 1H NMR in DMSO
4.100
3.638
4.777

21. Zn[bhedtc]2 1H NMR in DMSO
Up: 0.163
Down: 0.084
Down: 0.149

22. Hg[bhedtc]2 1H NMR in DMSO
Up: 0.220
Down: 0.108
Down: 0.234

23. Pb[bhedtc]2 1H NMR in DMSO
Down: 0.095
Up: 0.208
Down: 0.134

24. K[bhedtc] 13C NMR in DMSO

25. 13C NMR results

26. K[bhedtc] IR

27. Ca[bhedtc]2 over K[bhedtc]

28. Cr[bhedtc]3 over K[bhedtc]

29. Zn[bhedtc]2 over K[bhedtc]

30. Hg[bhedtc]2 over K[bhedtc]

31. K[UO2(bhedtc)3] over K[bhedtc]

32. Pb[bhedtc]2 over K[bhedtc]

33. UV-Vis

34. Mass Spec Complexes Mass/Charge ratio (m/z) Molecular Weight (amu)
Ca[bhedtc]2
401.2
400.2
Cr[bhedtc]3 ~
Zn[bhedtc]2
425.0
424.0
Hg[bhedtc]2
563.0
562.0
K[UO2(bhedtc)3]
810.4
849.5
Pb[bhedtc]2
591.0
568.0
*Central Analytical Laboratory at University of Colorado at Boulder

35. Elemental Analysis
*Columbia Analytical Services, Tucson, Arizona

36. Conclusion Study of Zinc and Mercury is complete
Calcium, Chromium, and Uranium have a promising beginning
New complex formed
Pb[bhedtc]2

37. Future Work Self-Assembly Additional trials Rotary evaporator
Atomic Absorption Spectroscopy
Attempt more metals

38. Acknowledgements Big Thanks: McDaniel College Chemistry Department
Dr. Craig for the opportunity
Dr. Smith for advising the seminar process
Fran Wetzel for supplying reagents
Teresa Tilyou for her knowledge and assistance
Thao Tran and Kevin Bowman

39. References
Pages, A.; Casas, J.S.; Sanchez, A.; Sordo, J.; Bravo, J.; Gayoso, M. Dithiocarbamates in Heavy Metal Poisoning: Complexes of N,N-di(2-hydroxyethyl)dithiocarbamate with Zn(II), Cd(II), Hg(II), CH3Hg(II), and C6H5Hg(II). J. Inorg. Biochem. 1985, 25,
Fenton, D.E. More metalloenzymes. Biocoordination Chemistry; Oxford University Press Inc.: New York, 1995; pp
Johnston, M. Genetic evidence that zinc is an essential co-factor in the DNA binding domain of GAL4 protein. Nature. 1987, 328,
Facts About Dietary Supplements: Zinc. (accessed April 17, 2008), National Institute of Health, Office of Dietary Supplements.
Zinc in Drinking-water: Background document for development of WHO Guidelines for Drinking-water Quality; Technical Report for World Health Organization: Geneva, CH, 2003.
Mercury in Health Care; Policy Paper for World Health Organization: Geneva, CH, August 2005.
Exposure to Mercury: A Major Public Health Concern; Policy Paper for World Health Organization: Geneva, CH, 2007.

40. References
Depleted uranium. (accessed April 17, 2008), World Health Organization.
Lead in Paint, Dust, and Soil. (accessed August 15, 2008), Environmental Protection Agency.
Dietary Supplement Fact Sheet: Chromium. (accessed February 19, 2009), National Institute of Health, Office of Dietary Supplements.
Dietary Supplement Fact Sheet: Calcium. (accessed August 7, 2008), National Institute of Health, Office of Dietary Supplements.
Zhong, Y.; Zhang, W.; Fan J.; Tan, M.; Lai, C.S.; Tiekink, E.R.T. Bis[μ-N,N bis(2- hydroxyethyl)dithiocarbamato]-1:2κ3S,S’:S’;2:1κ3S,S’:S’-bis{[N,N-bis(2-hydroxyethyl)dithiocarbamate-κ2S,S’]cadmium(II)}. Acta Crystallogr., Sect. E: Struct. Rep. 2004, E60, m1633-m1635.
Zingaro, R.A. The Reaction of Uranyl Ion with Xanthates and Diethyldithiocarbamate. J. Am. Chem. Soc. 1956, 78,
Skoog, D.; Holler, F.; Crouch, S. Principles of Instrumental Analysis, 6th ed.; Thomson Brooks/Cole: Belmont, CA; pp 526, ,

41. Questions?