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Webinar Series

What's in my NMR tube? An overview to the process of structure characterization

January 27-February 24, 2021

Identifying "what's in your NMR tube (or rotor)", confirming if you really synthesized what you intended to, or assigning correct configurations from a molecular formula is not always an easy task and is often entrusted to advanced software tools for execution. At ACD/Labs we have a variety of NMR tools designed to help you confidently and efficiently characterize what you really have in your NMR tube.

In this webinar series we will take a comprehensive look into structure characterization of unknown compounds using NMR data and our software tools.

Webinar I

In the first webinar, we start by matching the spectral data against the entries from open access databases to check if the compound has been previously identified and avoid repetition of work (dereplication).

The next step in structure determination is to verify the match between a proposed structure and the experimental NMR data. Depending on the confidence level needed, there are 3 levels of structure verification. For the highest confidence level in the structures and to remove human intervention, Unbiased Verification (UBV) is recommended. In this workflow, the molecular formula is the only given parameter extracted from the proposed structure of the sample and used by the software to select the best structure among all plausible structures. Finally, we will briefly introduce structure elucidation of unknown structures with CASE. This topic will be continued in detail in the following webinar.

Webinar II

In the second webinar, we advance to unknown structure elucidation using computer assisted structure elucidation (CASE). CASE systems have significantly contributed to de novo structural elucidation of thousands of natural and synthesized compounds. Here, we will demonstrate how by using a molecular formula, CASE can find the chemical structure that best fits the spectral data. The steps taken during the process, including generation of a Molecular Connectivity Diagram (MCD), structure generation and ranking of results will be reviewed.

Additionally, complicated cases such as structures with unexpected correlations, spectral ambiguity, hydrogen deficiency and symmetrical molecules will be discussed. Finally, we will demonstrate how a 3D configuration can be determined from a 2D structure.

Dimitris Argyropoulos

Dimitris Argyropoulos, PhD (NMR Business Manager) obtained his PhD from the University of Athens, Greece. He joined ACD/Labs in 2015 where he has been working as an Application Scientist and an NMR Business Manager. Prior to joining ACD/Labs he worked at Varian (Agilent), UK as an NMR Applications Laboratory Manager.

Dr. Argyropoulos has extensive experience in structure determination and characterization of small molecules using NMR spectroscopy and MS, as well as NMR investigation of biomolecules and materials.

Yalda Liaghati Mobarhan

Yalda Liaghati Mobarhan, PhD (Marketing & Communications Specialist) obtained her PhD in Environmental Sciences from the University of Toronto. Her area of study focused on aquatic toxicity using in vivo NMR. She joined ACD/Labs in June of 2019, where she mainly oversees marketing and communications efforts for the NMR product lines.