These are preliminary reports that have not been peer-reviewed. They should not be regarded as conclusive, guide clinical practice/health-related behavior, or be reported in news media as established information. For more information, please see our FAQs.
2 files

Dialing in Direct Air Capture of CO2 by Crystal Engineering of Bis-iminoguanidines

submitted on 15.04.2020, 14:23 and posted on 17.04.2020, 15:18 by Radu Custelcean, Neil J. Williams, Xiaoping Wang, Kathleen A. Garrabrant, Halie Martin, Michelle K. Kidder, Alexander Ivanov, Vyacheslav S. Bryantsev
We report a structure-properties relationship study of DAC by crystallization of bis-iminoguanidine (BIG) carbonate salts. The study focuses on a series of basic BIG structures including the glyoxal-bis(iminoguanidine) prototype (GBIG) and its simple analogs methylglyoxal-bis(iminoguanidine) (MGBIG) and diacetyl-bis(iminoguanidine) (DABIG). We find that minor structural modifications in the molecular structure of GBIG, such as substituting one or two hydrogen atoms with methyl groups, result in major changes in the crystal structures, induced by the increased conformational flexibility and steric hindrance. As a result, the corresponding aqueous solubilities within the series increase significantly, leading in turn to enhanced DAC performances.


DOE Office of Science, Basic Energy Sciences


Email Address of Submitting Author


Oak Ridge National Laboratory



ORCID For Submitting Author


Declaration of Conflict of Interest

A US patent covering the DAC systems described in this manuscript has been filed (patent number 10583387, granted on March 10, 2020). R.C. currently seeks to license and commercialize a DAC technology based on the data presented in this manuscript.