-   Private construction business prior to 2002.

-   PhD in Physical Chemistry (2006) - Bruker Prize for best PhD

-   C2 NRF-rated scientist 

-   Ongoing green energy consultation work, i.e. in the fields of Green Hydrogen, Ammonia, Mobility, Solar, Wind and Battery Energy Storage

-   Practical Lab Research Techniques:

•     synthesis
•     electrochemistry
•     quantum computational chemistry
•     Single crystal X-ray crystallography, XRD, XRF, TGA, BET, SEM & TEM
•     Spectrophotometry:  femto-second ultra-fast laser, UV/vis, IR, ICP, AA, NMR & MS

 -   Fields of Research includes:

• photo- and electro-active chemical species
• photo-catalysts and charge transfer complexes
• atmospheric air, water and mine samples analyses
• development of carbon-based water filtration systems
• green hydrogen production &
• wood chemistry related to the construction industry.

          Present research focuses on commercializable projects

-   Lecture Analytical Chemistry courses from 2nd year upwards

  

.

 

 

 

1991

The crystal structure of the acetone adduct of trans-methyliodo-8-hydroxyquinolinatocarbonyltriphenylphosphinerhodium(III)

Van Aswegen, K. G.; Leipoldt, J. G.; Potgieter, I. M.; Lamprecht, G. J.; Van Zyl, G. J.

Transition Metal Chemistry, 16, 369-371, 1991

http://link.springer.com/article/10.1007%2FBF01024085

 

2008

A DFT Perspective on the Structures and Electronic Spectra of the Orange and Blue Isomers of Photochromic Dithizonatophenylmercury(II)

Von Eschwege, K. G.; Conradie, J.; Swarts, J. C.

J. Phys. Chem. A, 112 (11), 2211-2218, 2008

http://pubs.acs.org/doi/pdf/10.1021/jp076924r

 

2009

2,3-Bis(2-methoxyphenyl)tetrazolium-5-thiolate-acetone-dichloromethane

Von Eschwege, K. G.; Muller, A.

Acta Cryst. E65, o2, 2009

http://scripts.iucr.org/cgi-bin/paper?cv2466

 

2,3-Bis(3-fluorophenyl)tetrazolium-5-thiolate

Von Eschwege, K. G.; Muller, A.

Acta Cryst. E65, o1864, 2009

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2977314/

 

2010

Chemical and electrochemical oxidation and reduction of dithizone

Von Eschwege, K. G.; Swarts, J. C.

Polyhedron, 29, 1727-1733, 2010     

https://doi.org/10.1016/j.poly.2010.02.009

 

Low-temperature redetermination of 1,3-bis(pentafluorophenyl)triazene

Von Eschwege, K. G.; Kuhn, A.

Acta Cryst. E66, o3177, 2010

http://journals.iucr.org/e/issues/2010/12/00/kp2288/kp2288bdy.html

 

2011

Ultrafast Photochemistry of Dithizonatophenylmercury(II)

Schwoerer, H.; Von Eschwege, K. G.; Bosman, G.; Krok, P.; Conradie, J.

ChemPhysChem, 2653-2658, 2011

https://doi.org/10.1002/cphc.201100337

 

Electrochemical and DFT-modeled reduction of Enolized 1,3-Diketones

Kuhn, A.; Von Eschwege, K. G.; Conradie, J.

Electrochimica Acta, 56, 6211– 6218, 2011

https://doi.org/10.1016/j.electacta.2011.03.083

 

Electrochemistry and spectro-electrochemistry of dithizonatophenyl-mercury(II)

Von Eschwege, K. G.; Van As, L.; Swarts, J. C.

Electrochimica Acta, 56(27), 10064-10068, 2011

https://doi.org/10.1016/j.electacta.2011.08.094

 

Redox Potentials of Ligands and Complexes – a DFT Approach

(Invited publication)  Von Eschwege, K. G.; Conradie, J.

SA Journal of Chemistry, 64, 203–209, 2011

http://www.scielo.org.za/scielo.php?script=sci_arttext&pid=S0379-43502011000100028

 

Dithizone and its Oxidation Products – a DFT, Spectroscopic and X-Ray Structural Study

Von Eschwege, K. G.; Conradie, J.; Kuhn, A.

J. Phys. Chem. A, 115, 14637-14646, 2011

https://doi.org/10.1021/jp208212e

 

[1,5-Bis(2-methoxyphenyl)thiocarbazonato-k²N⁵,S]phenylmercury(II)

Von Eschwege, K. G.; Muller, F.; Muller, A.

Acta Cryst. E, E67, m1804, 2011

http://journals.iucr.org/e/issues/2011/12/00/zq2138/zq2138sup0.html

 

[1,5-Bis((4-fluoropheny)thiocarbazonato-k²N⁵,S]phenylmercury(II) dichloromethane hemisolvate

Von Eschwege, K. G. Muller, F.; Muller, A.

Acta Cryst. E, E67, m1858, 2011

http://journals.iucr.org/e/issues/2011/12/00/zq2140/zq2140bdy.html

 

2012

Reduction potentials of para-substituted nitrobenzenes

- a theoretical approach

Kuhn, A.; Von Eschwege, K. G.; Conradie, J.

J. Phys. Org. Chem. 25, 58-68, 2012

https://doi.org/10.1002/poc.1868

 

Oxidation resilient dithizones - synthesis, cyclic voltammetry and DFT perspectives

Von Eschwege, K. G.

Polyhedron, 39, 99–105, 2012

https://doi.org/10.1016/j.poly.2012.03.028

 

(E)-1-[2-(Methylsulfanyl)phenyl]-2-({(E)-2-[2-methylsulfanyl)phenyl]hydrazinylidene}(nitro)methyl)diazene

Von Eschwege, K. G.; Muller, F.; Hosten, E. C.

Acta Cryst. E, E68, o199-o200, 2012

http://scripts.iucr.org/cgi-bin/paper?zq2147

 

1,5-Bis(2-methylphenyl)-3-nitroformazan

Von Eschwege, K. G.; Hosten, E. C.; Muller, A.

Acta Cryst. E, E68, o425, 2012

http://scripts.iucr.org/cgi-bin/paper?kp2378

 

(E)-1-[2-(Methoxyl)phenyl]-2-({(E)-2-[2-(methoxyl)phenyl]hydrazinylidene}(nitro)methyl)diazene

Von Eschwege, K. G.; Muller, F.; Hill, T. N.

Acta Cryst. E, E68, o609, 2012

http://journals.iucr.org/e/issues/2012/03/00/is5057/is5057.pdf

 

(1,5-Diphenylthiocarbazonato-KS)trimethyltin(IV)

Von Eschwege, K. G.; Swarts, J. C.; Aquino. M. A. S.; Cameron, T. S.

Acta Cryst. E, E68, m1518, 2012

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3588764/

 

 

2013

Synthesis and kinetics of electronically altered photochromic dithizonatophenylmercury(II) complexes

Von Eschwege, K. G.

J. Photochem & Photobiol., 252, 159-166, 2013       

https://doi.org/10.1016/j.jphotochem.2012.11.009

 

Intramolecular interactions in a new tris-dithizonatocobalt(III) complex

Von Eschwege, K. G.; Van As, L. Joubert, C. C.; Swarts, J. C.; Aquino, M. A. S.; Cameron, T. S.

Electrochimica Acta, 112, 747–755, 2013

https://doi.org/10.1016/j.electacta.2013.08.192

 

2014

Femtosecond Laser Spectroscopy and DFT studies of Photochromic Dithizonatomercury Complexes

Von Eschwege, K.G.; Bosman, G.; Conradie, J.; Schwoerer, H.

dx.doi.org/10.1021/jp410186y | J. Phys. Chem. A 2014, 118, 844-855

http://pubs.acs.org/doi/abs/10.1021/jp410186y

 

Synthesis and Kinetics of Sterically Altered Photochromic Dithizonatomercury Complexes

Alabaraoye, Ernestine; Von Eschwege, K. G.* and Loganathan, Nagarajan

J. Phys. Chem. A, 2014, 118 (46), 10894–10901.

http://pubs.acs.org/doi/pdf/10.1021/jp5076324

 

2015

Merck Medal for most significant publication in the SA Journal of Chemistry over the last 4 year period is awarded for our 2011 publication.

 

2016

Synthesis and structure of dithizonato complexes of antimony(III), copper(II) and tin(IV)

Trevor T. Chiweshe, Marilé Landman, Jeanet Conradie & Karel G. von

Eschwege

Journal of Coordination Chemistry, 2016, 69(5) 788–800

http://dx.doi.org/10.1080/00958972.2016.1145213

 

Electronic properties of Fe charge transfer complexes – A combined experimental and theoretical approach

Hendrik Ferreira, Karel G. von Eschwege, Jeanet Conradie

Electrochimica Acta 216 (2016) 339–346,

http://dx.doi.org/10.1016/j.electacta.2016.09.034

 

2017

Electrochemical and DFT study of the reduction of substituted phenanthrolines

Hendrik Ferreira, Marrigje M. Conradie, Karel G. von Eschwege, Jeanet Conradie

Polyhedron 122 (2017) 147–154       

http://dx.doi.org/10.1016/j.poly.2016.11.018

 

Spectrophotometry Mole Ratio and Continuous Variation Experiments with Dithizone

Lumanyano L. A. Ntoi;  Karel G. von Eschwege,

African Journal of Chemical Education-AJCE 7(2) (2017) 59-92.

https://www.ajol.info/index.php/ajce/article/view/160436

 

Seven Chromisms associated with Dithizone

Lumanyano L. A. Ntoi, Blenerhassied Buitendach, Karel G. von Eschwege

Journal of Physical Chemistry A (2017) 121, 9243-9251

DOI: 10.1021/acs.jpca.7b09490

 

2018

Iron Phenanthrolines:  A Density Functional Theory Study

Karel G. von Eschwege;  Jeanet Conradie

Inorganica Chimica Acta (2018) 471, 391–396        

https://doi.org/10.1016/j.ica.2017.11.047

 

2019

Synthesis and kinetics of photochromic carboxy-substituted dithizonatophenylmercury(II)

Lumanyano L.A. Ntoi, Orbett T. Alexander, Karel G. von Eschwege

J. Photochemistry and Photobiology A: Chemistry 368 (2019) 219-226

https://doi.org/10.1016/j.jphotochem.2018.09.031    

 

Electrochemistry and spectroscopy of substituted [Ru(phen)3]²⁺ and [Ru(bpy)3]²⁺ complexes

Deidre van der Westhuizen, Karel G. von Eschwege, Jeanet Conradie

Electrochimica Acta 320 (2019) 134540(1-9)

https://doi.org/10.1016/j.electacta.2019.07.051         

 

Electrochemistry data of [Ru(phen)₃]²⁺ and [Ru(bpy)₃]²⁺ complexes

Karel G. von Eschwege, Jeanet Conradie

Data in Brief, 27 (2019) 104759

https://doi.org/10.1016/j.dib.2019.104759

 

2020

Cyclic voltammograms and electrochemical data of FeII polypyridine

complexes

J. Conradie, K.G.von Eschwege

Data in Brief 31 (2020) 105754

https://doi.org/10.1016/j.dib.2020.105754

 

Electrochemistry of Os Bipyridyl and Phenanthroline Complexes, Comparison with Ru and Fe

D. van der Westhuizen, J. Conradie, K.G. von Eschwege

Electroanalysis (2020)

https://doi.org/10.1002/elan.202060300

 

Polypyridine OsII complexes electrochemical dataJ. Conradie,

D. van der Westhuizen, A. Kannan, J. Conradie, K.G.von Eschwege

Data in Brief 33 (2020) 106454

https://doi.org/10.1016/j.dib.2020.106454

 

Conformational preference of nitroformazans: A computational study

F.M.A. Muller, K.G.von Eschwege, J. Conradie

J. Molecular Structure 1203 (2020) 127463

https://doi.org/10.1016/j.molstruc.2019.127463

 

Synthesis, DFT and kinetic studies of chromic S-methyldithizone

F.M.A. Muller, J. Conradie, K.G. von Eschwege

Polyhedron 179 (2020) 114386

https://doi.org/10.1016/j.poly.2020.114386

 

Probing ultrafast reaction mechanisms of photo-excited dithizone through transient absorption spectroscopy and computational CASSCF studies

A.A. Adeniyi, P-F.X. von Stein, G.W. Bosman, C.M. Steenkamp, T. Chiweshe, K.G. von Eschwege, J. Conradie

J. Optical Soc. of America B 37 (2020) A356

https://doi.org/10.1364/JOSAB.399082

 

2021

Mn(II/III) oxidation of tris(polypyridine)manganese(II) complexes, Electrochimica Acta, Zinhle Mtshali, Karel G.von Eschwege, Jeanet Conradie, Electrochemical study of the 391 (2021) 138965

https://doi.org/10.1016/j.electacta.2021.138965

 

2022

Review of DFT-simulated and experimental electrochemistry properties  of the polypyridyl Row-1  Mn, Fe & Co,  and Group-8  Fe, Ru and Os  MLCT complexes

Karel G. von Eschwege* and Jeanet Conradie*

Electrochemistry Communications 136 (2022) 107225

https://doi.org/10.1016/j.elecom.2022.107225

 

Review of DFT-simulated and experimental electrochemistry properties of the polypyridyl Row-1 Mn, Fe & Co, and Group-8 Fe, Ru and Os MLCT complexes

KG von Eschwege, J Conradie

Electrochemistry Communications 136 (2022) 107225

https://doi.org/10.1016/j.elecom.2022.107225

 

Redox Data of Tris(polypyridine)manganese(II) Complexes

Z Mtshali, KG Von Eschwege, J Conradie

Data 7 (2022) 130

https://www.mdpi.com/2306-5729/7/9/130

 

Atmospheric fine particulate matter (PM_2.5) in Bloemfontein, South Africa

International Journal of Environmental Analytical Chemistry (2022) 1-16

Deidré van der Westhuizen, Chantelle Howlett-Downing, Peter Molnár, Johan Boman, Janine Wichmann, Karel G von Eschwege

https://www.tandfonline.com/doi/abs/10.1080/03067319.2022.2154664

 

Synthesis and characterization of CuO@ S-doped gC 3 N 4 based nanocomposites for binder-free sensor applications

Nigussie Alebachew, HC Ananda Murthy, Bedassa Abdissa, Taye B Demissie, Karel G von Eschwege, Ernst HG Langner, Liza Coetsee-Hugo

RSC advances 12 (2022) 29959-29974

https://pubs.rsc.org/en/content/articlelanding/2022/ra/d2ra04752g

 

2023

Nanocomposites with ZrO₂@S-Doped g-C₃N₄ as an Enhanced Binder-Free Sensor: Synthesis and Characterization

Nigussie Alebachew, HC Ananda Murthy, Bedasa Abdisa Gonfa, Karel G

von Eschwege, Ernst HG Langner, Elizabeth Coetsee, Taye B Demissie

ACS omega 8 (2023) 13775-13790

https://pubs.acs.org/doi/10.1021/acsomega.2c08174

 

2024

Source apportionment of fine atmospheric particles in Bloemfontein, South      

Africa, using positive matrix factorization

Deidré van der Westhuizen, Chantelle Howlett-Downing, Peter Molnár,

Johan Boman, Janine Wichmann, Karel G von Eschwege