Temperature-Dependent Superhydrophobic Functionalized Coordination Polymers (SFCPs) for Selective Adsorption of C2H4 over C2H6

We prepared two new superhydrophobic functionalized coordina-tion polymers (SFCPs) [Zn-4(OH)(2)(BTMB)(2)(4,4 '-Bipy)(2)]infinity superset of solvent, 1, and [Cd-4(OH)(2)(BTMB)(2)(4,4 '-Bipy)(3)](infinity) superset of solvent, 2, by solvothermal methods. For 1, the single-crystal XRD structure revealed that it contains two crystallographically distinct Zn2+ ions with two different types of coordination geometries of 4 and 6, exhibiting a unique superhydrophobic behavior with microporosity. Compound 1 exhibits superhydrophobicity with a contact angle of 155.5 degrees (at 30 degrees C), which is stable even at high temperatures, whereas for the SFCP 2, all of the Cd2+ ions have only 6-coordination and exhibit a superhydrophobic character at room temperature with a contact angle of 156.7 degrees(at 30 degrees C). However, surprisingly, this superhydrophobic character is stable only up to 60 degrees C, above which it is converted to hydrophilic nature, in contrast to the SFCP 1. Moreover, in this study, we also report a selective gas adsorption study of two C2 gases with similar kinetic diameters (similar to 3.9 A) of ethylene over ethane.