These are preliminary reports that have not been peer-reviewed.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.
3 files

What’s in an Atom? a Comparison of Carbon and Silicon-Centered Amidinium···carboxylate Frameworks

submitted on 18.08.2020, 07:33 and posted on 19.08.2020, 07:35 by Stephanie Boer, Li-Juan Yu, Tobias Genet, Kaycee Low, Duncan Cullen, Michael Gardiner, Michelle Coote, Nicholas White

Despite their apparent similarity, framework materials based on tetraphenylmethane and tetraphenylsilane building blocks often have quite different structures and topologies. Herein, we describe a new silicon tetraamidinium compound and use it to prepare crystalline hydrogen bonded frameworks with carboxylate anions in water. The silicon-containing frameworks are compared with those prepared from the analogous carbon tetraamidinium: when biphenyldicarboxylate or tetrakis(4-carboxyphenyl)methane anions were used similar channel-containing networks are observed for both the silicon and carbon tetraamidinium. When terephthalate or bicarbonate anions were used, different products form. Insights into possible reasons for the different products are provided by a survey of the Cambridge Structural Database and quantum chemical calculations, both of which indicate that, contrary to expectations, tetraphenylsilane derivatives have less geometrical flexibility than tetraphenylmethane derivatives, i.e. they are less able to distort away from ideal tetrahedral bond angles.


Australian Research Council DE170100200


Email Address of Submitting Author


Australian National University



ORCID For Submitting Author


Declaration of Conflict of Interest

No conflict of interest