Synthesis and Crystal Structure of Two Cyano Bridged dimeric 4f-3d Complexes

Two cyano bridged dimeric 4f 3d complexes [Nd(DMF) 4(H 2O) 3Co(CN) 6]·H 2O (A) and [Sm(pyr) 4(H 2O) 3Cr(CN) 6]·2H 2O (B) (DMF=N,N dimethylformamide, pyr=2 pyrrolidone) were prepared and structurally characterized. Single crystal X ray diffraction analysis revealed that the complexes contain cyano bridged 3 and [Ln(L) 4(H 2O) 3] 3+ groups. The Ln 3+ is eight coordinate, and is coordinated by seven oxygen atoms of three water molecules and four organic ligands (DMF or pyr). Each terminal CN ligand of the 3- entity is hydrogen bonded to some oxygen atoms of the coordinated water molecules yielding a hydrogen bonded three dimensional network. Crystal data for A: monoclinic, space group P 2(1)/ n , a = 1.7525(4) nm, b =0.8879(2) nm, c =1.9876(4) nm, β =95.92(3)°, V =3.0763(12) nm 3, Z =4, D c= 1.563 mg·m -3 . Complex B crystallizes in the P 1 space group, with lattice parameters of a =1.22720(4) nm, b =1.45550(8) nm, c =0.91310(4) nm, α =92.5869(17)°, β = 90.9569(12)°, γ =89.822(3)°, V =1.62908(13) nm 3, Z =2, D c=1.608 mg·m -3 .

Synthesis, Characterization and Crystal Structure of the First Tri-nuclear MFe_2 (M=Cu and Ni) Complexes Based on Nitroprusside

Three new complexes [Ni(H2L)][Fe(CN)(5)(NO)](2)(.)6H(2)O (1), [Ni(H2L)][Fe(CN)(5)(NO)](2)(.)4H(2)O (2) and [Cu(H2L)][Fe-(CN)(5)(NO)](2)(.)4H(2)O (3) (L=3,10-bis(2-aminoethyl)-1,3,5, 8,10,12-hexaazacyclotetradecane) are prepared and characterized by IR, elemental analyses and single-crystal X-ray analyses, indicating that they are the first examples of trinuclear nitroprusside-bridged MFe2(M = Cu and Ni) complexes. In the three complexes, the central metal atoms (M) are all six-coordinated by the nitrogen atoms from the macrocyclic ligand and two cyano-bridges at the trans-positions to form distorted octahedral configurations. The axial N-M-N linkage is nearly vertical to the equatorial plane defined by four coordinating N atoms of macrocyclic ligand. The Cequivalent toN-Ni bond angle of 172.6degrees in complex 1 is apparently larger than those in complexes 2 and 3 (152.57degrees and 136.37degrees, respectively). The three complexes are all connected by hydrogen bonds into 3D networks. This study shows that the cyano-bridged trinuclear species could be generated via the control of the charge of the building blocks.