A two-dimensional flexible porous coordination polymer based on Co(ii) and terpyridyl phosphine oxide†
Two porous coordination polymers, Co-Py2PO and Co-Py2PO′, have been obtained via reactions of in situ oxidized terpyridyl phosphines and cobalt(II) nitrate. Single-crystal structure analysis reveals that Co-Py2PO′ has a three-dimensional (3D) structure with (8·102)(83) net topology, while the structural analysis of Co-Py2PO reveals a 2D polycatenated framework consisting of two sets of parallel 2D networks of (63) net topology. For Co-Py2PO′, guest CHCl3 molecules are locked in the channels along the b axis by P(O)Ph2 phenyl rings and coordinated nitrate ions, and cannot be released out of the host framework. In contrast, the as-synthesized 2D framework Co-Py2PO readily loses its solvated guest molecules to give an activated amorphous material for sorption. Activated Co-Py2PO has a flexible structure and shows dynamic adsorption behaviours towards various guests (N2 and benzene). The flexibility may arise from the combination of layer–layer motion and the local flexibility of the P–C bond of –P(O)Ph2 groups.
- This article is part of the themed collection: Crystal engineering for molecular materials