*Article* **From Frustrated Packing to Tecton-Driven Porous Molecular Solids**

### **Chamara A. Gunawardana 1, Abhijeet S. Sinha 1, Eric W. Reinheimer 2 and Christer B. Aakeröy 1,\***


Received: 24 February 2020; Accepted: 10 March 2020; Published: 13 March 2020

**Abstract:** Structurally divergent molecules containing bulky substituents tend to produce porous materials via frustrated packing. Two rigid tetrahedral cores, tetraphenylmethane and 1,3,5,7-tetraphenyladamantane, grafted peripherally with four (trimethylsilyl)ethynyl moieties, were found to have only isolated voids in their crystal structures. Hence, they were modified into tecton-like entities, tetrakis(4-(iodoethynyl)phenyl)methane [**I4TEPM**] and 1,3,5,7-tetrakis(4-(iodoethynyl)phenyl)adamantane [**I4TEPA**], in order to deliberately use the motif-forming characteristics of iodoethynyl units to enhance crystal porosity. **I4TEPM** not only holds increased free volume compared to its precursor, but also forms one-dimensional channels. Furthermore, it readily co-crystallizes with Lewis basic solvents to a fford two-component porous crystals.

**Keywords:** crystal engineering; porous material; molecular recognition; halogen bond; co-crystal; molecular tecton; binary solid; network structure; σ-hole; molecular electrostatic potential
