Microporosity of a Guanidinium Organodisulfonate Hydrogen‐Bonded Framework

Guanidinium organosulfonates (GSs) are a large and well‐explored archetypal family of hydrogen‐bonded organic host frameworks that have, over the past 25 years, been regarded as nonporous. Reported here is the only example to date of a conventionally microporous GS host phase, namely guanidinium 1,4‐benzenedisulfonate ( p ‐G 2 BDS ). p ‐G 2 BDS is obtained from its acetone solvate, AcMe@ G 2 BDS , by single‐crystal‐to‐single‐crystal (SC‐SC) desolvation, and exhibits a Type I low‐temperature/pressure N 2 sorption isotherm (SA BET =408.7(2) m 2  g −1 , 77 K). SC‐SC sorption of N 2 , CO 2 , Xe, and AcMe by p ‐G 2 BDS is explored under various conditions and X‐ray diffraction provides a measurement of the high‐pressure, room temperature Xe and CO 2 sorption isotherms. Though p ‐G 2 BDS is formally metastable relative to the “collapsed”, nonporous polymorph, np ‐G 2 BDS , a sample of p ‐G 2 BDS survived for almost two decades under ambient conditions. np ‐G 2 BDS reverts to z CO 2 @ p ‐G 2 BDS or y Xe@ p ‐G 2 BDS ( y,z =variable) when pressure of CO 2 or Xe, respectively, is applied.