catena-Poly[[[tetra­kis­(cyanido-κC)tungstate(IV)]-di-μ-cyanido-κ4 C:N-bis­[diaqua­(2,2′-bipyridyl-κ2 N,N′)manganese(II)]-di-μ-cyanido-κ4 N:C] hexa­hydrate]

Noriaki Ozaki; Ryo Yamada; Koji Nakabayashi; Shin-ichi Ohkoshi

doi:10.1107/S1600536811012451

. 2011 May 7;67(Pt 6):m702–m703. doi: 10.1107/S1600536811012451

catena-Poly[[[tetrakis(cyanido-κC)tungstate(IV)]-di-μ-cyanido-κ⁴ C:N-bis[diaqua(2,2′-bipyridyl-κ² N,N′)manganese(II)]-di-μ-cyanido-κ⁴ N:C] hexahydrate]

Noriaki Ozaki ^a, Ryo Yamada ^a, Koji Nakabayashi ^a, Shin-ichi Ohkoshi ^a,^*

PMCID: PMC3120535 PMID: 21754606

Abstract

The polymeric title compound, {[Mn^II ₂W^IV(CN)₈(C₁₀H₈N₂)₂(H₂O)₄]·6H₂O}_n, has a one-dimensional cyanide-bridged Mn^II–W^IV bimetallic assembly. The coordination geometry of the W^IV atom is eight-coordinate square-antiprismatic and that of each of the Mn^II atoms is six-coordinate distorted octahedral. Two pairs of CN ligands of W(CN)₈ are bridged to two Mn^II atoms, the remaining CN ligands being terminal. Each Mn^II 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.

Related literature

For general background to octacyanidotungstates as magnetic materials, see: Ohkoshi et al. (2007 ▶, 2008 ▶); Sieklucka et al. (2009 ▶). For related octacyanidotungstate structures, see: Herrera et al. (2003 ▶); Leipoldt et al. (1994 ▶); Sieklucka et al. (2000 ▶).

Experimental

Crystal data

[Mn₂W(CN)₈(C₁₀H₈N₂)₂(H₂O)₄]·6H₂O
M _r = 992.40
Monoclinic,
a = 11.6673 (3) Å
b = 15.5511 (4) Å
c = 21.4339 (7) Å
β = 99.213 (1)°
V = 3838.78 (18) Å³
Z = 4
Mo Kα radiation
μ = 3.70 mm⁻¹
T = 90 K
0.90 × 0.20 × 0.02 mm

Data collection

Rigaku R-AXIS RAPID diffractometer
Absorption correction: multi-scan (ABSCOR; Higashi, 1995 ▶) T _min = 0.135, T _max = 0.930
33108 measured reflections
8606 independent reflections
7342 reflections with I > 2σ(I)
R _int = 0.062

Refinement

R[F ² > 2σ(F ²)] = 0.036
wR(F ²) = 0.079
S = 1.03
8606 reflections
533 parameters
18 restraints
H atoms treated by a mixture of independent and constrained refinement
Δρ_max = 2.47 e Å⁻³
Δρ_min = −1.92 e Å⁻³

Data collection: PROCESS-AUTO (Rigaku, 2007 ▶); cell refinement: PROCESS-AUTO; data reduction: CrystalStructure (Molecular Structure Corporation & Rigaku, 2007 ▶); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: ORTEP-3 (Farrugia, 1997 ▶) and VESTA (Momma & Izumi, 2006 ▶); software used to prepare material for publication: CrystalStructure.

Supplementary Material

Crystal structure: contains datablocks I, global. DOI: 10.1107/S1600536811012451/tk2734sup1.cif

e-67-0m702-sup1.cif^{(43.5KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536811012451/tk2734Isup2.hkl

e-67-0m702-Isup2.hkl^{(421KB, hkl)}

Additional supplementary materials: crystallographic information; 3D view; checkCIF report

Table 1. Hydrogen-bond geometry (Å, °).

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
O1—H1⋯O10ⁱ	0.84 (2)	2.02 (2)	2.822 (5)	162 (5)
O1—H2⋯O9ⁱⁱ	0.84 (2)	2.04 (3)	2.834 (4)	156 (5)
O2—H3⋯O6ⁱⁱⁱ	0.83 (2)	1.87 (2)	2.703 (4)	173 (5)
O2—H4⋯N6ⁱ	0.82 (2)	2.25 (2)	3.052 (4)	165 (5)
O3—H6⋯O6^iv	0.83 (2)	1.92 (2)	2.744 (4)	176 (5)
O3—H5⋯N5^iv	0.82 (2)	2.48 (3)	3.238 (4)	153 (4)
O4—H8⋯O5^iv	0.83 (2)	2.12 (2)	2.907 (5)	159 (4)
O4—H7⋯O9^v	0.84 (2)	1.89 (2)	2.722 (4)	174 (4)
O5—H30⋯N6^vi	0.84 (2)	2.13 (2)	2.946 (5)	164 (5)
O5—H29⋯O1ⁱ	0.84 (2)	2.32 (3)	3.111 (4)	157 (5)
O6—H32⋯O7	0.83 (2)	1.97 (2)	2.773 (4)	162 (5)
O6—H31⋯O5	0.83 (2)	1.97 (3)	2.753 (4)	157 (4)
O7—H34⋯N8ⁱ	0.82 (2)	2.02 (2)	2.810 (5)	159 (4)
O7—H33⋯N5	0.83 (2)	2.09 (2)	2.915 (5)	175 (4)
O8—H35⋯N7^vii	0.83 (2)	2.03 (2)	2.840 (5)	165 (5)
O8—H36⋯O7	0.83 (2)	2.03 (2)	2.854 (4)	174 (5)
O9—H38⋯N6^vii	0.84 (2)	2.66 (3)	3.372 (5)	143 (4)
O9—H37⋯O8	0.83 (2)	1.91 (2)	2.715 (5)	161 (5)

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Symmetry codes: (i) Inline graphic ; (ii) ; (iii) ; (iv) ; (v) ; (vi) ; (vii) .

Acknowledgments

The present research was supported in part by a Grant-in-Aid for Young Scientists (S) from JSPS, the Core Research for Evolutional Science and Technology (CREST) program of the Japan Science and Technology Agency (JST), Grant for the Global COE Program, "Chemistry Innovation through Cooperation of Science and Engineering", the Photon Frontier Network Program from MEXT, Japan, the Center for Nano Lithography & Analysis, The University of Tokyo, supported by MEXT Japan, the Izumi Science and Technology Foundation, and The Asahi Glass Foundation.

supplementary crystallographic information

Comment

In the field of molecular-based magnets, octacyanotungstate [W(CN)₈]-based magnetic materials are intensively studied due to their functionalities, e.g. high Curie temperature (Sieklucka et al., 2009), photo-magnetism (Ohkoshi et al., 2008), and chemically sensitive magnetism (Ohkoshi et al., 2007). Octacyanotungstates of [W(CN)₈], which can adopt different configurations depending on the coordinating ligands (Leipoldt et al., 1994), also display various structures and dimensionalities. For example, in Mn^II—W^IV cyano-bridged systems, zero-dimensional Mn^II₄[W^IV(CN)₈]₂(2,2'-bipyridyl)₈.14H₂O (Sieklucka et al., 2000) and three-dimensional Mn^II₂[W^IV(CN)₈](2,2'-bipyrimidine).2H₂O (Herrera, et al., 2003) have been reported. In this work, we report a one-dimensional cyano-bridged Mn^II—W^IV bimetallic assembly with a bidentate ligand of 2,2'-bipyridyl, [Mn^II₂(C₁₀H₈N₂)₂(OH₂)₄][W^IV(CN)₈](C₁₀H₈N₂)₂.6H₂O, (I).

Fig. 1 shows the asymmetric unit of (I). W1 has an eight-coordinated square-anti-prismatic geometry, where four CN groups of [W(CN)₈] are bridged to Mn1 and Mn2, and the other four CN groups being non-bridging. The coordination geometries of Mn1 and Mn2 are a six-coordinated distorted octahedral. Each Mn atom is coordinated to two nitrogen atoms derived from two CN groups, two nitrogen atoms from 2,2'-bipyridyl, and two oxygen atoms from two water molecules. The asymmetric unit has six zeolitic water molecules. Fig. 2 shows the polymeric structure of (I). The successive connections between W^IV and Mn^II ions result in the formation of a one-dimensional structure along the b axis.

The product of the molar magnetic susceptibility (χ_M) and temperature (T), χ_MT, at room temperature was determined to be 8.6 cm³ K mol^-1. This value nearly agrees with the expected value of 8.8 cm³ K mol^-1 due to two Mn^II (S = 5/2, g = 2). The χ_MT value gradually decreased below 10 K. This behaviour indicates that the Mn^II centres antiferromagnetically interact with each other.

Experimental

Single crystals of the target compound were prepared by diffusion of aqueous solutions of Mn^IICl₂4H₂O (3 ml, 0.12 mmol) with 2,2'-bipyridyl (0.13 mmol) and K^I₄[W^IV(CN)₈]2H₂O (3 ml, 0.051 mmol) in a test tube. The tube was left in the dark at room temperature, and the yellow platelets grew after several days. Inductively coupled plasma atomic emission spectrometry and CHN elemental analysis confirmed that the formula as (I) less two water molecules. Calculated: C 34.94, H 3.74, N 17.47, Mn 11.43, W 19.13%; found C 34.94, H 3.65, N 17.31, Mn 11.37 W 18.99%. The difference in the number zeolitic water molecules between the elemental analysis and the crystallographic formulation arises as zeolitic water molecules are easy lost from the crystals during the drying process. The CN stretching peaks for Mn^II—NC—W^IV were observed at 2161, 2146, 2134, 2128, 2124, 2110, 2103 and 2081 cm^-1 in the IR spectrum. In the UV-vis diffuse reflectance spectrum, a broad absorption band was observed with a maximum at 430 nm, which was assigned to the metal-metal charge transfer (MMCT) band of W^IV—CN—Mn^II.