catena-Poly[[[tetrakis(cyanido-κC)tungstate(IV)]-di-μ-cyanido-κ⁴C:N-bis[diaqua(2,2′-bipyridyl-κ²N,N′)manganese(II)]-di-μ-cyanido-κ⁴N:C] hexahydrate]

Abstract

The polymeric title compound, {[MnII 2WIV(CN)8(C10H8N2)2(H2O)4]·6H2O}n, has a one-dimensional cyanide-bridged MnII–WIV bimetallic assembly. The coordination geometry of the WIV atom is eight-coordinate square-anti­prismatic and that of each of the MnII atoms is six-coordinate distorted octa­hedral. Two pairs of CN ligands of W(CN)8 are bridged to two MnII atoms, the remaining CN ligands being terminal. Each MnII atom is additionally coordinated by a bidentate 2,2′-bipyridyl ligand and two water mol­ecules. The crystal structure is stabilized by O—H⋯O and O—H⋯N hydrogen bonds.

Two Cyanide-Bridged MnII–NbIV Coordination Chain Ferrimagnets Promoted by Interchain Ferromagnetic Interactions

“…Such a topology was reported previously for the diamagnetic octacyanotungstate­(IV) and octacyanomolybdate­(IV) analogues, ,, but was not observed for octacyanoniobate­(IV). In the structure of 1 , of monoclinic space group P 2 1 / c , the asymmetric unit contains two Mn II and one Nb IV .…”

“…The one-pot reactions facilitated the control of concentration of possible manganese­(II) complexes, reduced the risk of byproduct formation, such as Mn 4 Nb 2 hexanuclear clusters, and enabled the isolation of compounds 1 and 2 pure enough for a reliable physical characterization. Slow diffusion methods were avoided in contrast to the previously reported syntheses of Mn II –[M­(CN) 8 ] compounds with 2,2′-bipyridine. , …”

“…Furthermore, the hydrogen-bonding network is additionally supported by an extended π–π stacking of bipyridyl rings along the b axis (the chain direction), with the closest distances between the planes of the rings being 3.58 and 3.63 Å (Figure S5). The structural analysis of the octacyanotungstate­(IV) analog gives the corresponding π–π distances equal to 3.61 and 3.98 Å, which leads to a conclusion that incorporation of the larger tungsten­(IV) cation with a geometry of a square antiprism instead of the dodecahedral niobium­(IV) causes uneven distortion of the π–π interactions in the W IV analog.…”

“…Octacyanoniobate­(IV) anion [Nb IV (CN) 8 ] 4– has been proved to be an efficient building block in the construction of discrete zero-dimensional (0-D) , and extended two- (2-D) , and three-dimensional (3-D) − coordination frameworks that show many different functionalities. − However, only two 1-D coordination architectures have been constructed with the use of this building block: , an SCM {[(H 2 O)­Fe II (L)]­[Nb IV (CN) 8 ]­[Fe II (L)]·4.5H 2 O} n (L = pentadentate macrocycle) and its Mn II analogue {[(H 2 O)­Mn II (L)]­[Nb IV (CN) 8 ]­[Mn II (L)]·5H 2 O} n a simple paramagnet with a possible magnetic ordering around 2 K. We find the lack of 1-D coordination systems based on octacyanoniobate­(IV) quite surprising, taking into account a variety of 1-D structures based on its diamagnetic analogues: octacyanomolybdate­(IV) , and octacyanotungstate­(IV), , which should encourage the preparation of the niobium­(IV) congeners. Therefore, we decided to focus our attention on new 1-D coordination assemblies of manganese­(II) and octacyanoniobate­(IV) by using 2,2′-bipyridine (bpy) as a blocking ligand.…”

“…Slow diffusion methods were avoided in contrast to the previously reported syntheses of Mn II −[M(CN) 8 ] compounds with 2,2′-bipyridine. 17,20 Crystal Structures. The structure of 1 built of 1-D CNbridged ribbon-like coordination chains of Nb-vertex-sharing Mn 2 Nb 2 squares is shown in Figure 2.…”