title: Structural flexibilities and gas adsorption properties of one-dimensional copper(II) polymers with paddle-wheel units by modification of benzoate ligands.
abstract: CO2 and N2 gas adsorption/desorption properties of one-dimensional copper(II) polymers with paddle-wheel units [Cu(II)2(p-XBA)4(pyrazine)]∞ were successfully controlled through the tuning of interchain interactions by modification of para-substituent X groups on the benzoate (BA) ligands (X = Cl, Br, I, and OCH3). Although none of the four crystals had sufficient void space to integrate the crystallization solvents, gate-opening gas adsorption and desorption behaviors coupled with structural phase transitions were observed for CO2 (T = 195 K) and N2 (T = 77 K), with differences depending on the precise substituent. van der Waals interchain interactions, specifically π···π, halogen···π, and C-H···π contacts, were dominant in forming the crystal lattice; their magnitude was associated with gate-opening pressure and hysteresis behaviors. Both the type and magnitude of the interactions were evaluated by Hirshfeld surface analysis, which indicated that structural flexibility decreased as larger halogen atoms were included. Overall, weak interchain interaction and structural flexibility generated new void spaces to adsorb CO2 and N2 gases.
authors.affiliation: Graduate School of Engineering, Tohoku University , Sendai 980-8579, Japan.
authors.forename: Kiyonori
authors.initials: K
authors.lastname: Takahashi
authors.affiliation: Graduate School of Engineering, Tohoku University , Sendai 980-8579, Japan.|Institute of Multidisciplinary Research for Advanced Materials (IMRAM), Tohoku University , 2-1-1 Katahira, Aoba-ku, Sendai 980-8577, Japan.
authors.forename: Norihisa
authors.initials: N
authors.lastname: Hoshino
authors.affiliation: Graduate School of Engineering, Tohoku University , Sendai 980-8579, Japan.|Institute of Multidisciplinary Research for Advanced Materials (IMRAM), Tohoku University , 2-1-1 Katahira, Aoba-ku, Sendai 980-8577, Japan.
authors.forename: Takashi
authors.initials: T
authors.lastname: Takeda
authors.affiliation: Research Institute for Electronic Science, Hokkaido University , Sapporo 001-0020, Japan.
authors.forename: Shin-Ichiro
authors.initials: S
authors.lastname: Noro
authors.affiliation: Research Institute for Electronic Science, Hokkaido University , Sapporo 001-0020, Japan.
authors.forename: Takayoshi
authors.initials: T
authors.lastname: Nakamura
authors.affiliation: Graduate School of Science, Hokkaido University , Sapporo 060-0810, Japan.
authors.forename: Sadamu
authors.initials: S
authors.lastname: Takeda
authors.affiliation: Graduate School of Engineering, Tohoku University , Sendai 980-8579, Japan.|Institute of Multidisciplinary Research for Advanced Materials (IMRAM), Tohoku University , 2-1-1 Katahira, Aoba-ku, Sendai 980-8577, Japan.
authors.forename: Tomoyuki
authors.initials: T
authors.lastname: Akutagawa