Research Interests

Astro- and Prebiotic Chemistry

Many reactive molecules have been already detected in interstellar media by microwave spectroscopy. Some of them are not stable here on Earth under ambient conditions but stabilized by the very low temperatures and pressure in space. Larger molecules can be formed there by barrierless chemical reactions in the gas phase or by light induced photochemistry in ices in the solid state. It is worth to study the formation of biomolecules in space towards the understanding how life could have been emerged on early Earth and which prebiotic chemical reactions could have been contributed to these complex reaction networks.

Selected publications:

A. K. Eckhardt,^‡ M. M. Linden,^‡ R. C. Wende, B. Bernhardt and P. R. Schreiner Nat. Chem., 2018, 10, 1141–1147, doi:10.1038/s41557-018-0128-2. (^‡ = contributed equally)
A. K. Eckhardt, R. C. Wende and P. R. Schreiner J. Am. Chem. Soc., 2018, 140, 12333–12336, doi:10.1021/jacs.8b07480.
A. K. Eckhardt,^‡ A. Bergantini,^‡ S. K. Singh, P. R. Schreiner and R. I. Kaiser Angew. Chem Int. Ed., 2019, 58, 5663–5667, doi:10.1002/anie.201901059. (^‡ = contributed equally)
N. F. Kleimeier,^‡ A. K. Eckhardt,^‡ P. R. Schreiner and R. I. Kaiser Chem, 2020, 6, 3385–3395, doi:10.1016/j.chempr.2020.10.003. (^‡ = contributed equally)

Chemical Reactivity and Physical (In)Organic Chemistry

For the understanding of chemical reactivity it is necessary to combine and compare experimental and theoretical results. Nowadays, high-level computations on small molecules are very reliable and go most of the time hand in hand with experimental physical organic measurements. At low temperatures quantum mechanical tunneling dominates chemical reactivity of light particles and even governs chemical selectivity. This phenomena is known as tunneling control of a chemical reaction, a third reactivity principle besides the established concept of thermodynamic and kinetic control. Quantum mechanical tunneling processes open new pathways to reaction products that cannot be formed in a classic way.

Selected publications:

A. K. Eckhardt, D. Gerbig and P. R. Schreiner J. Phys. Chem. A, 2018, 122, 1488–1495, doi:10.1021/acs.jpca.7b12118.
A. K. Eckhardt, F. R. Erb and P. R. Schreiner Chem. Sci., 2019, 10, 802–810, doi:10.1039/C8SC03720E.
C. M. Nunes, A. K. Eckhardt, I. Reva, R. Fausto and P. R. Schreiner J. Am. Chem. Soc., 2019, 141, 14340–14348, doi:10.1021/jacs.9b06869.
A. K. Eckhardt, M.-L. Y. Riu, P. Müller and C. C. Cummins Inorg. Chem., 2022, 61, 1270–1274, doi:10.1021/acs.inorgchem.1c03753.

Reactive Intermediates and Matrix Isolation Spectroscopy

Reactive intermediates play a key role in most of every chemical reaction. It is necessary to study the stability and reactivity of these intermediates towards the understanding of chemical reaction mechanisms and fine tuning of chemical reactions. Typical highly reactive intermediates include carbenes, radicals and nitrenes that can be trapped at cryogenic temperatures and studied by matrix isolation spectroscopy.

Selected publications:

A. K. Eckhardt and P. R. Schreiner Angew. Chem Int. Ed., 2018, 57, 5248–5252, doi:10.1002/anie.201800679.
Z. Wu, C. Chen, J. Liu, Y. Lu, J. Xu, X. Liu, G. Cui, T. Trabelsi, J. S. Francisco, A. Mardyukov, A. K. Eckhardt, P. R. Schreiner and X. Zeng J. Am. Chem. Soc., 2019, 141, 3361–3365, doi:10.1021/jacs.8b12746.
N. F. Kleimeier, A. K. Eckhardt^* and R. I. Kaiser J. Am. Chem. Soc., 2021, 143, 14009–14018, doi:10.1021/jacs.1c07978. (^* = corresponding author)

Phosphorus Chemistry

Elemental phosphorus mainly exists in two forms, white and red phosphorus, but is never found as a free element on Earth because of its high reactivity. However, phosphorus is an element essential to sustaining life largely through phosphates (PO₄³⁻). Phosphates are a component of DNA, RNA, ATP, and phospholipids.
Air and moisture sensitive phosphorus species can be prepared under inert nitrogen or argon atmospheres using Schlenk techniques or directly inside a glovebox and analyzed by ³¹P NMR spectroscopy as well as in single-crystal X-ray diffraction experiments. As phosphorus bearing molecules like, e.g. PN, have already been detected in space but do not exist under standard laboratory conditions here on Earth, we are interested in the synthesis of simple phosphorus bearing molecules of interstellar interest as well as their spectroscopic analysis and chemical reactivity.

Selected publications:

A. K. Eckhardt, M.-L. Y. Riu, M. Ye, P. Müller, G. Bistoni and C. C. Cummins Nat. Chem., 2022, doi:10.1038/s41557-022-00958-5. (ChemRxiv)
A. K. Eckhardt, M.-L. Y. Riu, P. Müller and C. C. Cummins J. Am. Chem. Soc., 2021, 143, 21252–21257, doi:10.1021/jacs.1c11426. (ChemRxiv)
C. Zhu,^‡ A. K. Eckhardt,^‡ A. Bergantini, S. K. Singh, P. R. Schreiner and R. I. Kaiser Sci. Adv., 2020, 6, eaba6934, doi:10.1126/sciadv.aba6934. (^‡ = contributed equally)
C. Zhu, A. K. Eckhardt,^* S. Chandra, A. M. Turner, P. R. Schreiner and R. I. Kaiser Nat. Commun., 2021, 12, 5467, doi:10.1038/s41467-021-25775-1. (^* = corresponding author)