News

March 2017: Abu-Omar current and past members at the GRC on Inorganic Reaction Mechanisms, Galveston, TX

                                                                                          

Front row left to right: Mike Zdilla (Professor, Temple University), Shuo Liu (Postdoc, Columbia University), Thilina Gunasekara (TG) (PhD Student), Keith Steelman (Chemist, Dow Chemical Co.) Back row left to right: Mike Gau (Zdilla's PhD student), Mahdi Abu-Omar, Elon Ison (Professor, NC State University), and Curt Bougher (PhD Student)

 

December 2016: Abu-Omar Holiday Party

                              

                              

 

February 2016: Mechanistic investigation of the Zn/Pd/C catalyzed cleavage and hydrodeoxygenation of lignin

While current biorefinery processes use lignin only for its heat value, the conversion of lignin to high value chemicals is an area of increasing interest. Herein we present a detailed mechanistic study of the hydrodeoxygenation (HDO) of lignin by using a synergistic Pd/C and ZnII catalyst through use of both lignin model compounds and lignocellulosic biomass. Spectroscopic data coupled with the study of lignin model compounds suggest that ZnII activates and facilitates removal of the hydroxyl group at the Cγ position of the β-O-4 ether linkage. Activation is proposed to occur through formation of a six-membered ring complex of ZnII coordinated to the oxygen atoms at Cα and Cγ of the lignin model compound guaiacylglycerol-β-guaiacyl. Read More>>

 

February 2016: Mechanism of Isomerization and Methyl Migration in Heterobimetallic Rhenium–Iridium Complexes: Experimental and DFT Study

Investigation of the mechanism of conversion of the bimetallic complex [PNP(H)Ir-μ(CH2)-μ(O)-Re(O)2][PF6] (1) to its structural isomer [PNP(Me)(CH3CN)Ir-ReO3][PF6] (2) by detailed kinetics and DFT computational studies is reported. The reaction proceeds by intramolecular rearrangement of 1 to [PNP(Me)Ir-ReO3][PF6] (S) via a methyl-bridged [PNP(H)Ir-μ(CH3)-Re(O)3]- [PF6] (P) intermediate followed by CH3CN coordination. The rate-determining step is the transformation of 1 to P displaying ΔG⧧ of 21.8 kcal/mol. Experimental kinetic results include zero-order dependence on acetonitrile, positive ΔS⧧, and deuteration of the bridging methylidene group in the reaction of 1 with CD3OD. All of these results support the proposed mechanism. Read More>>

February 2016: Total Utilization of Miscanthus Biomass, Lignin and Carbohydrates, Using Earth Abundant Nickel Catalyst

A two-step catalytic conversion of raw biomass into different high value chemicals (phenol products, levulinic acid and furfural) was established using earth abundant Ni/C and FeCl3 catalysts. Read More>>