Thomas E. Müller

During his early research, Müller worked on organometallic chemistry with an interest in the hydroamination of alkenes and alkynes. His research on the catalytic activity of transition metals on the hydroamination of alkynes revealed that [Cu(CH₃CN)₄]PF₆ and group 12 metals salts have the highest catalytic activity and that of d8 or d10 electronic configuration is present in all catalytically active complexes.[6] In another research he analyzed the Palladium-Catalyzed Cyclization of 6-Aminohex-1-yne and observed [Pd(Triphos)](CF₃SO₃)₂ complex has the highest catalytic activity[7] and also mentioned that ion-exchanged zeolites are at least as active in the hydroamination of 6-aminohex-1-yne as the corresponding homogeneous catalysts.[8] Later, he observed that the presence of protons drastically increases the rate of hydroamination reactions catalyzed by Lewis acidic metals[9] and that supported Rh(I), Pd(II) and Zn(II) complexes have particularly high catalytic activity and selectivity.[10]

Apart from finding new catalysts for the hydroamination of alkenes and alkynes, Müller has also determined the X-ray crystal structure of the transition-metal catalyst [PdCl(triphos)](CF₃SO₃) that is active for the intra-molecular hydroamination of alkynes[11] and novel hydroamination reactions in a liquid–liquid two-phase catalytic system which showed efficient results.[12]

Müller is most known for his work in the polymer industry, especially for his approach towards creating multiple sustainable processes for the synthesis and formation of polymers, including a process for manufacturing poly oxazolidinone polymer compounds.[13] He also proposed a method to synthesize polyether ester carbonate polyols by catalytically adding alkylene oxide and carbon dioxide to an H-functional initiator substance in the presence of a double metal cyanide catalyst.[14] Afterwards, he established a process of creating heterocycle-functional polyoxyalkylene polyol by reacting polyoxyalkylene polyol having unsaturated groups with a heterocyclic compound[15] as well as a method for producing polyether thiocarbonate polyols,[16] multiple bond-containing prepolymer as elastomer precursor,[17] and for the synthesis of polyoxazolidinone compounds.[18]

Müller's has elucidated reaction pathways at the initial steps of trioxane polymerization and provided molecular-level insight which benefits further production and properties of polyoxymethylene.[19] In addition to that, he introduced a method for substituting ether units in polyether polyols with oxymethylene moieties to obtain Hydroxy-terminated polyoxymethylene-co-polyoxyalkylene multi-block telechels.[20] A Density Functional Theory (DFT) study evaluated that the co-polymerization of CO₂ and ethylene by palladium catalyst is feasible if the ligand set is chosen properly.[21]

In the area of Carbon dioxide chemistry, Muller has focused on catalysis, facile insertions, and utilization of carbon dioxide and technologies related to it. He distinguished the features of [Cr(babhq)(EtOH)](CF₃CO₂−) to use it as a catalyst for the reaction of carbon dioxide with epoxides[22] and characterized a novel carbon dioxide (CO₂) utilization. The research evaluated that the polyether carbonate polyols synthesized from carbon dioxide with customized CO₂ content can aid in producing polyurethanes.[23] Studying the activation of carbon dioxide with in situ ATR-IR spectroscopy and DFT calculations his work revealed insertion of CO₂ into metal–phenoxide bonds to be facile[24] and that CO₂ insertion into cobalt(III)-oxygen bonds are exothermic.[25]

In the later part of Müller's career, his research focus shifted to technologies for closing anthropogenic carbon cycles. Carbon is a chemical element with the symbol C and atomic number 6. It is an essential element of life on Earth, forming the backbone of most organic molecules, including DNA, RNA, and proteins, sugars, cellulose and lignin. The carbon cycle is the process by which carbon moves through Earth's various reservoirs, including the atmosphere, oceans, land, and biosphere.[26] Carbon is continuously exchanged between these reservoirs through a variety of processes, including photosynthesis, respiration, decomposition, and fossil fuel combustion. The increase in atmospheric CO₂ concentration has led to a phenomenon known as global warming, which has serious consequences for the planet's ecosystems and human societies. He has proposed efforts to establish anthropogenic carbon cycles[27] that seek to understand and manage the flow of carbon through human activities, such as industrial processes, transportation, and agriculture.[28][29]