Hydrogen bonding principles in inclusion compounds of triphenylsilanol and pyrrolidine: Synthesis and structural features of [(Ph3SiOH)4·HN(CH2)4] and [Ph3SiOH·HN(CH2)4·CH3CO2H]

• The inclusion behaviour of triphenylsilanol towards pyrrolidine and acetic acid is reported.
• The well-balanced hydrogen donor and acceptor abilities of silanols are shown for two supramolecular assemblies.
• X-ray crystal structures are discussed in terms of their unique hydrogen bonding patterns.
• Insight into the bonding situation in between a silanol and an ammonium siloxide is presented.

The inclusion of small molecules, such as amines, into hydrogen-bonded assemblies is an important task for a selective enclathration of substance mixtures. Here we report on a convenient method to entrap a simple monoamine by using the acidic nature of a silanol hydroxyl group. In detail, the co-crystallisation of triphenylsilanol and pyrrolidine leading to a defined host–guest compound (1) with a 4:1 stoichiometric composition is presented. The addition of acetic acid to a mixture of the silanol and the amine resulted in the formation of co-crystals (2) comprising the three substances in a 1:1:1 ratio. The structural features, especially in terms of hydrogen-bonding interactions are discussed for both compounds.

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