The discovery of new materials for separating ethane from ethylene is a critical enterprise in the chemical industry. It still remains a daunting challenge to target both high C 2 H 6 adsorption and selectivity in a C 2 H 6 -selective material. Herein, we report a reversible solid-state transformation in a labile hydrogen-bonded organic framework to generate a new rod-packing desolvated framework (ZJU-HOF-1), leading to the suitable cavity spaces and functional surfaces to optimally interact with C 2 H 6 . ZJU-HOF-1 thus exhibits simultaneously high C 2 H 6 uptake (88 cm 3 g -1 at 0.5 bar and 298 K) and C 2 H 6 /C 2 H 4 selectivity (2.25), notably higher than HOF-76a and most of top-performing materials. Theoretical calculations reveal that the suitable cage-like cavities and functional sites to synergistically "match" better with C 2 H 6 provide stronger multipoint interactions with C 2 H 6 than C 2 H 4 . In combination with its high stability and ultralow water uptake, this material can efficiently capture C 2 H 6 from 50/50 C 2 H 6 /C 2 H 4 mixtures at ambient conditions under 60% RH, providing a record polymer-grade C 2 H 4 productivity of 0.98 mmol g -1 reported so far, as evidenced through the breakthrough experiments.