M. Y. Darensbourg Research Group Members

Spring 2013 - It's the MYD Group! Gig 'em!!

Back: Steven Montalvo, Randara Pulukkody, Ethel Mejia, Rachel Chupik, Tiffany Pinder, Danielle Crouthers, Shengda Ding
Front: Pokhraj Ghosh, Scott Harman, Prof. Marcetta Y. Darensbourg, Ryan Bethel, Allen Lunsford, Chung-Hung (Mark) Hsieh, Jason Denny

Current Group Members

Ning Wang
ning.wang@chem.tamu.edu

Ning Wang will be joining the MYD group in January 2014.

Chung-Hung Hsieh (Mark)
chung.hsieh@chem.tamu.edu

Mark's research focuses on biomimetic model studies on the synthesis and characterization of mononuclear N-heterocyclic carbene containing Dinitrosyl Iron Complexes (DNICs), interconversions among these series of {Fe(NO)₂}^9/10 species and transformation of nitric oxide from DNICs to the bio-relative NO trapping agents.

Ryan Bethel
rbethel@chem.tamu.edu

Ryan's research focuses on the investigation of the structure and reactivity of small molecule mimics of the [FeFe]-hydrogenase active site. His work involves the synthesis of dissymmetrically substituted complexes based on the (μ-pdt)[Fe(CO)₃]₂ parent model complex. Other projects include ongoing investigations into novel ligand substitutions for the creation of more effective electrocatalytic production of hydrogen from model complexes. His investigations also include the use of DFT calculations, in addition to the more common spectroscopic means of characterizing the complexes.

Jason Denny
jason.denny@chem.tamu.edu

The goals of Jason’s research are to develop understanding of the coordination chemistry appropriate to nickel trafficking and exchange in well defined biomolecules via three specific aims: 1) Determine the reaction conditions that lead to Ni(μ-SR)₂Ni dimer cleavage or reformation based on exogenous ligands or pH control, to contribute to understanding of the roles of bimetallic Ni binding sites in proteins such as HypB or monometallic sites such as NikR, both of which are involved in protein aggregation. 2) Examine the effect of S-acetylation on metal binding properties and metal exchange reactivity between metal complexes and exogenous metal ions in relation to modification of cysteinyl sulfurs by such agents. 3) Determine factors which influence transfer of nickel from an N₄ binding site, to a tight N₂S₂ binding site mimicking the Ni-storage area in the histidine-rich portion of certain proteins.

Danielle Crouthers
daniel.crouthers@chem.tamu.edu

Danielle’s work focuses on synthesis and characterization of [FeFe]-hydrogenase active site models. The primary focus on the research involves the substitution of various ligands and bridging Fe-Fe dithiolates with the goal of attaining a working model of the system.

Randara Pulukkody
randara.pulukkody@chem.tamu.edu

There is much interest in the field of bioinorganic chemistry on dinitrosyl iron complexes (DNICs) due to their relevance in the biological system. Randara is studying the base promoted tautomerization of imidazole to N heterocyclic carbenes on DNIC moieties, in order to mimic reactivity of histidine containing DNICs in the living system.

Allen Lunsford
allen.lunsford@chem.tamu.edu

Allen's research will focus on the synthesis and characterization of EPR active iron nitrosyl and vanadyl N₂S₂ compounds. Specifically, the line broadening effects of binuclear paramagnetic compounds and the relaxation rates.

Rachel Chupik
rachel.chupik@chem.tamu.edu

The focus of Rachel's research is the synthesis and characterization of copper and iron in nitrogen/sulfur ligation as dimeric and monomeric complexes. Cleavage of dimers by various ligands presents N₂SS' or N₂SL monomers of import to biologically relevant deaggregation processes. She also works on the development of water-soluble, bioconjugated DNIC's for possible use as NO release agents.

Pokhraj Ghosh
pokhraj.ghosh@chem.tamu.edu

The active site of the diiron hydrogenase is of particular interest to synthetic inorganic chemists for its ability to catalyze the reversible reduction of protons to form hydrogen gas. The N₂S₂M (M= Fe, Co, Ni) complexes are known for their ability to lower the reduction potentials on coordination with M(CO)_x. Ghosh’s work mainly focuses on the synthesis and characterization of [FeFe]-hydrogenase active site model compounds with N₂S₂M complexes as donor ligands.

Shengda Ding
shengda.ding@chem.tamu.edu

Shengda’s research focuses on the molecular modelling of the new-generation mimics of the Fe-Fe hydrogenase, involving one or more non-innocent NO ligands. His interest includes the investigation into the electronic structures of Fe(NO)–(N₂S₂)–Fe(NO)₂ model and its derivatives, in an effort to elucidate the vital role played by the well-delocalized electrons, which are shared by metal and its bound NOs. He is also working to propose a reasonable mechanism of H₂ production catalyzed by this series of hydrogenase mimics.

Yankee Tavern 2013 - The MYD and DJD Groups and friends!!!

Back: Shengda Ding, Fu-Te Tsai, Pokhraj Ghosh, Nolan Rush, Justin Fair, Jason Denny, Ryan Bethel, Chris Beto, Michael Drummond, Scott Harman
Middle: Joanna Chung, Yanyan Wang, Danielle Crouthers, Tiffany Pinder, Stephanie Wilson, Allen Lunsford, Prof. Donald J. Darensbourg, Rachel Chupik, Melissa Lee, Andrew Yeung, Samuel Kyran, Julio Cedeno, Seth Cochran
Front: Ethel Mejia, Mark Hsieh, Prof. Marcetta Y. Darensbourg, Randara Pulukkody

Spring 2013

Back: Chung-Hung (Mark) Hsieh, Jason Denny, Ryan Bethel, Allen Lunsford, Scott Harman
Front: Pokhraj Ghosh, Tiffany Pinder, Shengda Ding, Prof. Marcetta Y. Darensbourg, Rachel Chupik, Danielle Crouthers, Steven Montalvo, Randara Pulukkody, Ethel Mejia

Summer 2012
End of Summer @ Yankee Tavern!!!

Tree: Rachel Chupik, Stephanie Wilson, Ryan Bethel, Scott Harman, Sam Kyran
Back: Pokhraj Ghosh, Sheng-Hsuan Wei, Allen Lunsford, Scott Brothers, Steven Montalvo, Jason Denny
Front: Guangpeng Wu, Prof. Don Darensbourg, Chung-Hung Hsieh, Nick Zaibaq,
Floor: Bo Li, Ethel Mejia, Prof. Marcetta Darensbourg, Danielle Crouthers

Summer 2011
End of Summer @ Yankee Tavern!!!

Back: Andrew Yeung, Sam Kyran, Yuraima Fonseca, Erica Schepp, Joanna Chung, Ross Poland, Matt Knestrick, Scott Brothers, Sunshine Wei, Jason Denny, Ryan Bethel, Jen Hess
Front: Scott Harman, Randara Pulukkody, Danielle Crouthers, Susan Butch, "Biker Frank", Mark Hsieh, Tiffany Pinder, Prof. Don J. Darensbourg, Prof. Marcetta Y. Darensbourg
Floor: Stephanie Wilson, Ethel Mejia

Spring 2011

Back: Danielle Crouthers, Jen Hess, Jason Denny, Ryan Bethel, Scott Brothers
Front: Prof. Marcetta Y. Darensbourg, Ethel Mejia, Chung-Hung (Mark) Hsieh, Tiffany Pinder, Allen Lunsford, Randara Pulukkody, Rachel Chupik

Spring 2011 - WHOOP!

Fall 2012

Back: Chung-Hung (Mark) Hsieh, Pokhraj Ghosh, Prof. Marcetta Y. Darensbourg, Ryan Bethel, Jason Denny, Allen Lunsford
Front: Tiffany Pinder, Danielle Crouthers, Rachel Chupik, Randara Pulukkody-Gunaratna, Ethel Mejia

Fall 2010
The MYD and DJD Groups

Scott Brothers, Jason Denny, Prof. Don Darensbourg, Stephanie Wilson, Ross Poland, Michael Singleton, Sheng-Hsuan Wei, Ryan Bethel,
Chung-Hung Hsieh, Prof. Marcetta Darensbourg, Danielle Crouthers, Jennifer Hess, Wan-Chun Chung, Andrew Yeung,
Tiffany Pinder, Ethel Mejia, Osit Karroonnirun

Spring 2010

spring 2010
Chung-Hung Hsieh, Philip Duttweiler, Tiffany Pinder, Jason Denny, Jen Hess, Prof. Marcetta Darensbourg,
Scott Brothers, Danielle Crouthers, Roxanne Jenkins, Mike Singleton, Ryan Bethel

Spring 2009

summer 2009
Tianbiao Liu, Mike Singleton, BIn Li, Tiffany Pinder, Prof. Marcetta Darensbourg, Elky Almaraz, Jason Denny,
Roxanne Jenkins, Scott Brothers, Jen Hess, William Foley, Ryan Bethel

Summer 2008

Summer 2008
236^th ACS National Meeting, Philadelphia, PA
Dr. Jesse Tye, Roxanne Jenkins,Michael Singleton,
Elky Almaraz, Professor Marcetta Y. Darensbourg, Bin Li

Summer 2007

Former Group Members
Tiffany Pinder, Ph.D. 2013	Halliburton, Houston, TX
Scott Brothers, Ph.D. 2011	Assistant Professor of Chemistry, Bethany College
Jennifer Hess, Ph.D. 2011	Adjunct Faculty, Pasadena City College, Pasadena, CA
Philip Duttweiler, B.S. 2010	Quaility Control Lab Analyst, Kaneka Nutrients
Michael L. Singleton, Ph.D. 2010	Postdoctoral Research Associate, European Institute for Chemistry and Biology, University of Bordeaux I
Roxanne Jenkins, Ph.D. 2010	Research Scientist, Dow Chemicals
Alexander Todd, B.S. 2009	Research Technician, Univation Technologies
William Foley, M.S. 2009	Criminalist, Houston Police Department
Tianbiao Liu, Ph.D. 2009	Research Associate, Pacific Northwest National Laboratory
Elky Almaraz, Ph.D. 2008	Attending Law School
Kayla N. Green, Ph.D. 2007	Assistant Professor, Texas Christian University
Jesse W. Tye, Ph.D. 2006	Assistant Professor, Ball State University
Stephen P. Jeffery, Ph.D. 2006	Heraeus Metal Processing, Inc, California
Marilyn Rampersad Mackiewicz, Ph.D. 2005	Research Assistant Professor, Portland State University
Chao-Yi Chiang, Ph.D. 2005	Assistant Professor, Providence University, Taiwan
Melissa L. Golden, Ph.D. 2004	Assistant Professor, Fresno State University
Rosario Mejia Rodriguez, Ph.D. 2004	Professor, Universidad Autonoma de Queretaro, Mexico
Matthew L. Miller, Ph.D. 2003	Halliburton, Houston, TX
Irene P. Georgakaki, Ph.D. 2002	Government Laboratory, Greece
Xuan Zhao, Ph.D. 2002	Assistant Professor, University of Memphis
Erica J. Lyon, Ph.D. 2000	Assistant Professor, Bellarmine University
Jason J. Smee, Ph.D. 2000	Assistant Professor, University of Texas at Tyler
John A. Bellefeuille, Ph.D. 1999	Assistant Professor, Central Methodist University
Chia-Huei Lai, Ph.D. 1998	homemaker
Craig A. Grapperhaus, Ph.D. 1998	Associate Professor, University of Louisville
Ghezai Musie, Ph.D. 1997	Associate Professor, University of Texas-San Antonio
Rizalia Buonomo, Ph.D. 1996	Lecturer, Baylor University
Dawn Goodman, Ph.D. 1996	Eastman Chemical, Tennessee
Jeng Sub Kim, Ph.D. 1996	Industrial Chemist, Korea
Thawatchai Tuntulani, Ph.D. 1995	Professor, Chulalongkorn University, Bankok
Ivan Font, Ph.D. 1994	Merck Pharmaceuticals, Puerto Rico
Steve Chojnacki, Ph.D. 1993	Author and Chemistry Educator
Sheryl Wander, Ph.D. 1993	National Renewable Energy Laboratory
Yui May Hsaio, Ph.D. 1993	I.E. Dupont Corporation, Taipei, Taiwan
Patrick Farmer, Ph.D. 1993	Professor and Chair - Department of Chem. and Biochem., Baylor University, Waco, TX
Daniel Mills, Ph.D. 1991	Industrial Chemist, Ohio
Stephen Houliston, Ph.D. 1991	Industrial Chemist, Minnesota
Chris Janzen, Ph.D. 1991	Department Head & Associate Professor, Susquehanna University
Charles Riordan, Ph.D. 1990	Professor, University of Delaware
Jerry Springs, Ph.D. 1989	Kior, Houston, Texas
Wen Feng Liaw, Ph.D. 1989	Professor, National Tsing Hua University, Taiwan
Kay (Youngdahl) Blohowiak, Ph.D. 1987	Technical Fellow, The Boeing Company
Maria Ludvig, Ph.D. 1987	Albemarle Corporation, Houston, Texas
Carlton Ash, Ph.D. 1987	Shell Corporation
Yong Kwang Park, Ph.D. 1986	Professor, Kangwon National University, Korea
Patricia Tooley, Ph.D. 1986	Dupont Inc., Delaware
Larry Arndt, Ph.D. 1986	Industrial Chemist, Illinois
John Michael Hanckel, Ph.D. 1984	BASF Corporation, Charleston, SC
Haroldo Barros, Ph.D. 1980

Please forward any corrections/updates to:darensbourg_asst@chem.tamu.edu