An unusual 3D pillared-layer cobalt(II) coordination polymer containing helical motifs and novel topology constructed from mixed ligands

摘要

An unusual 3D pillared-layer Co~(II) coordination polymer, namely [Co(pda)(bpe)]_n (1) [H2pda = 1,3-phenylenediacetic acid, bpe=1,2-bi(4-pyridyl)ethylene], has been successfully prepared under hydrother-mal condition. X-ray crystal analysis indicates that the structure of 1 is constructed from 2D undulated [Co (pda)]_n layers, which consists of alternating left- and right-handed helical motifs, and then further pillared by bpe ligands into a 3D structural framework. Topologically, complex 1 shows an intriguing binodal (3,5)-connected fsc network with the Schlafli symbol of (4.6~2)(4.6~6.8~3) which is completely different from the reported (4,6)-connected fsc nets; and if the dimeric [Co2] units (SBUs) are considered as the single 6-connected nodes, 1 displays a familiar uninodal pcu net with the Schlafli symbol of (4~(12).6~3). In addition, magnetic measurement revealed that 1 shows the antiferromagnetic coupling between Co~(II) ions.