July 2011 – Present: 

Lecturer, Department of Chemistry, University of the Free State, Bloemfontein, South Africa

Areas of Responsibility:

• Training of post-graduate students to perform basic (e.g. 1D ¹H, ³¹P and ¹³C NMR), as well as more advanced (e.g. 2D NMR and solvent suppression) experiments on the 300 MHz Fourier, 400 MHz AVANCE III and 600 MHz AVANCE II Bruker NMR spectrometers. 

• The setting-up and acquisition of more complex NMR techniques, e.g. Magnetization Transfer experiments, 1D and 2D experiments of X nuclei, Multinuclear 2D experiments, ¹³CO exchange reactions, Low-temperature NMR and Determination interproton discances by NOE quantifications.

• The setting-up and acquisition of Solid-state NMR experiments.

• Applying these techniques to current research being done at the department.

• Be on the constant look-out for new NMR techniques that could benefit the research being done at the Chemistry Department.

October 2007 – June 2011: Senior Bioanalyst, PAREXEL Early Phase, Bloemfontein, South Africa

Areas of Responsibility:  Method development (extraction of exogenous and endogenous compounds from body fluids and other materials, followed by quantitative analysis with HPLC-MS/MS) and validation of analytical methods for the quantification of drugs in biological fluids.  Supervising of the production phases of quantitative and qualitative analytical procedures.  Assist and train bioanalysts in method development.

August 2001 – September 2005: Senior Scientist (Analytical Technology), Sasol Technology R&D, Sasolburg South Africa

Areas of Responsibility:  Operate Bruker 500MHz Avanche, Varian 600 MHz Inova and Varian 400MHz Mercury NMR spectrometers.  Perform 1D and 2D high-pressure NMR experiments in order to study various catalytic cycles by determining the structures of the catalytic species present during the different stages of the catalytic cycle.  Study the influence of different additives on catalytic species by using high pressure NMR techniques.  Determine percentage branching of detergent alcohols with NMR methods.  Structure elucidation of organic compounds obtained from different processes..

May 2000 – July 2001: Senior Scientist (Surfactant Research), Sasol Technology R&D, Sasolburg, South Afrcia

Areas of Responsibility:  Synthesize surfactant samples (ethoxylates, alcohol sulfates and ethoxylate sulfates) from various detergent alcohols.  Determine performance properties of surfactants e.g. surface properties, phase behavior, rheology and contact angles.  Interpret results and write reports.

Schutte-Smith, M., Roodt, A., Alberto, R., Twigge, L., Visser, H.G., Kirsten, L., Koen, R., Structures of rhenium(I) complexes with 3-hydroxyflavone and benzhydroxamic acid as O,O’-bidentate ligands and confirmation of p-stacking by solid-state NMR spectroscopy, Acta Cryst., 2019, C75, 378 – 387.

Manicum, A-L.E., Schutte-Smith, M., Alexander, O.T., Twigge, L., Roodt, A., Visser, H.G., First kinetic data of the CO substitution in fac-[Re(L,L’-Bid(CO)₃(X)] complexes (L,L’-Bid = acacetylacetonate or tropolonate) by tertiary phosphines PTA and PPh₃: Synthesis and crystal structures of water-soluble rhenium(I) tri- and dicarbonyl complexses with 1,3,5-triaza-7-phosphaadamantane (PTA), Inorganic Chemistry Communications, 2019, 101, 93 – 98. 

Loke, P.F., Kotzé, E., Du Preez, C.C., Twigge, L., Long-term effects of wheat production management practices on some carbon fractions of a semiarid Plinthustalfs, Soil Research, 2018, 56, 601 – 614. 

Swart, M.R., Twigge, L., Marais, C., Bezuidenhoudt, B.C.B., A variable temperature NMR analysis and resonance assignment of the Grubbs second generation catalyst, Polyhedron, 2018, 152, 31 – 36.

Stuurman, N.F., Buidendach, B.E., Twigge, L., Swarts, P.J., Conradie, J., Rhodium(triphenylphospine)carbonyl-2,4-dioxo-3-pentyl-4-decanyloxybenzoate: synthesis, electrochemistry and oxidative addition kinetics, New J. Chem., 2018, 42, 4121 – 4132.

Landman, M., Fraser, R., Twigge, L. and Conradie, J., Fischer aminocarbene conformers containing a 2-thienyl of 2-furyl ring: A crystallographic, NMR and DFT study, Journal of Coordination Chemistry, 2015, Vol. 68, No. 14, 2388 – 2408.

Purcell, W., Conradie, J., Chiweshe, T.T., Venter, J.A., Twigge, L. and Coetzee, M.P., Characterization and oxidative addition reactions of rhodium(I) carbonyl cupferrate diphenul-2-pyridylphosphine complexes, Journal of Organometallic Chemistry, 2013, 745-746: 439-453.

Ferreira A.C., Crous R., Bennie L., Meij A.M.M., Blann K., Bezuidenhoudt B.C.B., Young D.A., Green M.J., Roodt A., Borate esters as alternative acid promoters in the Palladium-catalyzed methoxycarbonylation of ethylene, Angew. Chem. Int. Ed., 2007, 46, 2273 – 2275.

Crous R., Datt M., Foster D., Bennie L., Steenkamp C., Huyser J., Kirsten L., Steyl G., Roodt A., Rhodium hydride formation in the presence of a bulky monophosphite ligand: a spectroscopic and solid-state investigation, Dalton Trans., 2005, 1108 – 1116.

Bennie L., Coetzee J., Malan E., Slade D., Marais J.P.J., Ferreira D., Trimeric proteracacinidins and a (6 ® 6)-bis-leucoteracacinidin from Acacia galpinii and Acacia caffra, Phytochemistry, Vol. 65, Issue 2 (2004), 215 – 220.

Crause C., Bennie L., Damoense L., Dwyer C.L., Grove C., Grimmer N., Janse van Rensburg W., Kirk M.M., Mokheseng K.M., Otto S., Steynberg P.J., Bicyclic phosphines as ligands for cobalt-catalysed hydroformylation, Dalton Trans., 2003, 2036 – 2042.

Bennie L., Coetzee J., Malan E., Ferreira D., (4®6)-Coupled proteracacinidins and promelacacinidins from Acacia galpinii and Acacia caffra, Phytochemistry, Vol. 60, Issue 5 (2002), 521 – 532.

Bennie L., Coetzee J., Malan E., Ferreira D., Structure and stereochemistry of dimeric proteracacinidins possessing the rare C-4(C)®C-5(D) interflavanyl linkage, Phytochemistry, Vol. 59, Issue 6 (2002), 673 – 678.

Bennie L., Coetzee J., Malan E., Ferreira D., Structure and stereochemistry of triflavanoids containing both ether and carbon-carbon interflavanyl bonds, Phytochemistry, Vol. 57, Issue 6 (2001), 1023 – 1034.

Bennie L., Coetzee J., Malan E., Woolfrey J.R., Ferreira D., Oligomeric flavanoids. Part 34: Doubly-linked proteracacinidin analogues from Acacia caffra and Acacia galpinii, Tetrahedron, Vol. 57, Issue 4 (2001), 661 – 667.

Bennie L., Coetzee J., Malan E., Ferreira D., Structure and synthesis of ether-linked proteracacinidin and promelacacinidin proanthocyanidins from Acacia caffra, Phytochemistry, Vol. 53, Issue 7 (2000), 785 – 7

Schutte-Smith, M., Roodt, A., Alberto, R., Twigge, L., Visser, H.G., Kirsten, L., Koen, R., Structures of rhenium(I) complexes with 3-hydroxyflavone and benzhydroxamic acid as O,O’-bidentate ligands and confirmation of p-stacking by solid-state NMR spectroscopy, Acta Cryst., 2019, C75, 378 – 387.

Manicum, A-L.E., Schutte-Smith, M., Alexander, O.T., Twigge, L., Roodt, A., Visser, H.G., First kinetic data of the CO substitution in fac-[Re(L,L’-Bid(CO)₃(X)] complexes (L,L’-Bid = acacetylacetonate or tropolonate) by tertiary phosphines PTA and PPh₃: Synthesis and crystal structures of water-soluble rhenium(I) tri- and dicarbonyl complexses with 1,3,5-triaza-7-phosphaadamantane (PTA), Inorganic Chemistry Communications, 2019, 101, 93 – 98. 

Loke, P.F., Kotzé, E., Du Preez, C.C., Twigge, L., Long-term effects of wheat production management practices on some carbon fractions of a semiarid Plinthustalfs, Soil Research, 2018, 56, 601 – 614. 

Swart, M.R., Twigge, L., Marais, C., Bezuidenhoudt, B.C.B., A variable temperature NMR analysis and resonance assignment of the Grubbs second generation catalyst, Polyhedron, 2018, 152, 31 – 36.

Stuurman, N.F., Buidendach, B.E., Twigge, L., Swarts, P.J., Conradie, J., Rhodium(triphenylphospine)carbonyl-2,4-dioxo-3-pentyl-4-decanyloxybenzoate: synthesis, electrochemistry and oxidative addition kinetics, New J. Chem., 2018, 42, 4121 – 4132.

Landman, M., Fraser, R., Twigge, L. and Conradie, J., Fischer aminocarbene conformers containing a 2-thienyl of 2-furyl ring: A crystallographic, NMR and DFT study, Journal of Coordination Chemistry, 2015, Vol. 68, No. 14, 2388 – 2408.

Purcell, W., Conradie, J., Chiweshe, T.T., Venter, J.A., Twigge, L. and Coetzee, M.P., Characterization and oxidative addition reactions of rhodium(I) carbonyl cupferrate diphenul-2-pyridylphosphine complexes, Journal of Organometallic Chemistry, 2013, 745-746: 439-453.

Liquid and Solid-state Multinuclear NMR Techniques.

Dynamic NMR.

Organic Synthesis.

CHEM1551 

CHEM1661

CHEM6853

CHEM6863

CHEM6808