title: Rational design of cavitand receptors for mass sensors.
abstract: This Communication describes a rational approach to the fabrication of selective mass sensors, using multiple hydrogen-bonding type interactions encoded in a single cavitand receptor. The introduction of two inward facing hydrogen bond acceptor PO groups at the upper rim of a cavitand renders the corresponding receptor layer deposited on a mass transducer highly selective toward alcohol vapors. The molecular origin of the increased selectivity has been identified in the presence of two energetically and geometrically equivalent interaction modes available to the guest, giving to the corresponding complexes an entropic advantage over their mono PO analogues.