Crystal Structures of New 2D Heteroligand Nd(III), Ho(III), and Yb(III) Coordination Polymers with 2-Iodoterephthalate Linkers

Novel Ln3+ and 2-iodoterephthalate based metal-organic frameworks [Nd2(2-I-bdc)3(DMF)4]·3.5DMF (1), [Ho2(2-I-bdc)3(DMF)4]·2.7DMF (2), [Yb2(2-I-bdc)3(DMF)4]·4.3DMF (3) (2-I-bdc - 2-iodoterephthalate, DMF - N,N-dimethylformamide) are prepared; their structure is determined by XRD. All three isostructural compounds contain a [Ln2(2-I-bdc)3(DMF)4] binuclear unit (Ln = Nd, Ho, Yb). The 2-I-bdc dianions exhibit two different types of coordination. In the first type, one carboxylate group is connected with one Ln(III) ion by two oxygen atoms and the other one is connected with two metal ions. One oxygen atom of the second carboxylate group is connected with only one metal center of the binuclear fragment, while the second oxygen is a bridging atom.