Cyano-Bridged LnIII−FeIIIComplexes with Alterative Monosulfoxides as Blocking Ligands.

The self-assembly reactions of Ln(NO 3) 3·aq (Ln = La, Nd, Sm, Gd, Dy, Er, and Yb) with K 3[Fe(CN) 6] and three monosulfoxide ligands, dimethylsulfoxide (DMSO), diethylsulfoxide (DESO), and tetramethylene sulfoxide (TMSO), respectively, in water give rise to three series of 21 Ln III−Fe IIIcomplexes with ten kinds of compositions and structures: cis-[Fe(CN) 4(μ-CN) 2La(H 2O) 3(DMSO) 3] n· nH 2O ( 1), [Fe(CN) 5(μ-CN)Ln(H 2O) 3(DMSO) 4]·H 2O [Ln = Nd ( 2), Dy ( 5)], [Fe(CN) 5(μ-CN)Ln(H 2O) 4(DMSO) 3]·H 2O [Ln = Sm ( 3), Gd ( 4)], trans-[Fe(CN) 4(μ-CN) 2Ln(H 2O)(DMSO) 4] n[Ln = Er ( 6), Yb ( 7)], [Fe(CN) 6][La(H 2O) 6(DESO) 3] ( 8), trans-[Fe(CN) 4(μ-CN) 2Ln(H 2O) 4(DESO) 2] n·2 nH 2O [Ln = Nd ( 9), Sm ( 10), Gd ( 11), Dy ( 12), Er ( 13)], cis-[Fe(CN) 4(μ-CN) 2Yb(H 2O) 3(DESO) 2] n·2 nH 2O ( 14), [Fe(CN) 5(μ-CN)Ln(H 2O) 3(TMSO) 4]·1.5H 2O [Ln = La ( 15), Nd ( 16), Gd ( 18)], cis-[Fe(CN) 4(μ-CN) 2Sm(H 2O) 4(TMSO) 2] n( 17) and cis-[Fe(CN) 4(μ-CN) 2Ln(H 2O) 3(TMSO) 2] n· nH 2O [Ln = Dy ( 19), Er ( 20), Yb ( 21)]. The X-ray structure analyses show that 2− 5, 15, 16, and 18have cyano-bridged dinuclear structures; 1, 6, 7, 9− 14, 17, and 19− 21form one-dimensional (1D) chain structures; but 8is an ionic compound without cyano-bridging. For those complexes with 1D structure, there are also different configurations ascribed to the cis- or trans-coordination of bridging CN −moieties to the Fe IIIion. The coordination of two CN −moieties to one Ln IIIion is all- trans(N−Ln−N > 90°), mainly due to the steric effect of Fe(CN) 63−entities. Further, such complexes feature extensive O−H···O and O−H···N hydrogen bonds that give rise to different three-dimensional (3D) supramolecular structures and stabilize and influence these structures. The differences of composition and structure of these complexes may be attributed to the structural differences of the three monosulfoxide blocking ligands, as well as different lanthanide ions to some extent, although a general rule (or underlying relationship) can not be deduced. [ABSTRACT FROM AUTHOR]