Tris{4-[(2H-tetra­zol-5-yl)meth­yl]morpholinium} dodeca­tungstophosphate hexa­hydrate

Babak Feizyzadeh; Masoud Mirzaei; Hossein Eshtiagh-Hosseini; Ahmad Gholizadeh

doi:10.1107/S1600536811003734

. 2011 Feb 5;67(Pt 3):m301–m302. doi: 10.1107/S1600536811003734

Tris{4-[(2H-tetrazol-5-yl)methyl]morpholinium} dodecatungstophosphate hexahydrate

Babak Feizyzadeh ^a,^*, Masoud Mirzaei ^b,^*, Hossein Eshtiagh-Hosseini ^b, Ahmad Gholizadeh ^c

PMCID: PMC3052096 PMID: 21522240

Abstract

The title heteropolyoxidotungstate-based inorganic–organic hybrid material, (C₆H₁₂N₅O)₃[W₁₂(PO₄)O₃₆]·6H₂O, consists of one α-Keggin-type [W₁₂(PO₄)O₃₆]³⁻ polyoxidometalate anion (POM), three crystallographically independent 4-[(2H-tetrazol-5-yl)methyl]morpholinium cations and six water molecules of crystallization. The morpholine ring of the cation adopts a chair conformation. The anion shows characteristic features with respect to bond lengths and angles. An extensive network of N—H⋯O, N—H⋯N, O—H⋯O and O—H⋯N hydrogen-bonding interactions between the organic cations, inorganic anion and the crystal water molecules lead to a three-dimensional structure. Moreover, six uncoordinated water molecules increase the number of hydrogen bonds in the network and lead to the formation of (H₂O)_∞ clusters.

Related literature

For other inorganic–organic hybrid materials based on polyoxidometalates with organic cations, see: Alizadeh et al. (2008a ▶,b ▶); Nikpour et al. (2009 ▶, 2010 ▶). For details of (H₂O)_n cluster analysis, see: Aghabozorg et al. (2010 ▶). For background to pseudopolymorphism, see: Desiraju (2003 ▶).

Experimental

Crystal data

(C₆H₁₂N₅O)₃[W₁₂(PO₄)O₃₆]·6H₂O
M _r = 3495.88
Orthorhombic,
a = 14.616 (3) Å
b = 15.213 (3) Å
c = 26.735 (6) Å
V = 5944 (2) Å³
Z = 4
Mo Kα radiation
μ = 23.27 mm⁻¹
T = 100 K
0.12 × 0.11 × 0.06 mm

Data collection

Bruker APEXII CCD area-detector diffractometer
Absorption correction: multi-scan (SADABS; Bruker, 2005 ▶) T _min = 0.078, T _max = 0.246
59635 measured reflections
12321 independent reflections
9617 reflections with I > 2σ(I)
R _int = 0.159

Refinement

R[F ² > 2σ(F ²)] = 0.052
wR(F ²) = 0.104
S = 1.00
12321 reflections
446 parameters
6 restraints
H-atom parameters constrained
Δρ_max = 2.80 e Å⁻³
Δρ_min = −2.72 e Å⁻³
Absolute structure: Flack (1983 ▶), 5544 Friedel pairs
Flack parameter: −0.041 (19)

Data collection: APEX2 (Bruker, 2005 ▶); cell refinement: SAINT (Bruker, 2005 ▶); data reduction: SAINT; program(s) used to solve structure: SHELXTL (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXTL; molecular graphics: SHELXTL; software used to prepare material for publication: publCIF (Westrip, 2010 ▶).

Supplementary Material

Crystal structure: contains datablocks I, global. DOI: 10.1107/S1600536811003734/wm2435sup1.cif

e-67-0m301-sup1.cif^{(38.5KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536811003734/wm2435Isup2.hkl

e-67-0m301-Isup2.hkl^{(602.4KB, 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
N4A—H4A⋯O2W	0.88	1.90	2.77 (2)	173
N5A—H5A⋯O5W	0.90	1.88	2.76 (3)	166
N4B—H4B⋯O1Wⁱ	0.88	1.84	2.71 (2)	168
N5B—H5B⋯N2Aⁱⁱ	0.90	2.31	2.97 (2)	130
N4C—H4C⋯O2W	0.88	2.09	2.87 (3)	149
N5C—H5C⋯O4W	0.87	2.01	2.71 (2)	137
O1W—H1W⋯O3Cⁱⁱⁱ	0.85	2.01	2.84 (2)	164
O1W—H2W⋯O3	0.85	1.92	2.77 (2)	180
O2W—H3W⋯O11T^iv	0.85	2.43	2.87 (2)	113
O2W—H4W⋯O9T^v	0.85	2.18	2.96 (2)	153
O2W—H4W⋯O2^vi	0.85	2.54	3.06 (2)	121
O3W—H5W⋯N1Aⁱⁱ	0.85	2.41	3.03 (3)	130
O3W—H6W⋯N2C	0.85	2.14	2.79 (3)	134
O4W—H7W⋯O7T	0.85	2.11	2.96 (2)	180
O4W—H8W⋯O6W^vii	0.85	2.00	2.82 (2)	161
O5W—H9W⋯O2W	0.85	1.99	2.82 (2)	164
O5W—H10W⋯O6W	0.85	1.93	2.78 (2)	178
O6W—H11W⋯N2B	0.85	2.11	2.85 (2)	146
O6W—H12W⋯O2T^v	0.85	2.25	2.91 (2)	134
O6W—H12W⋯O1W^vi	0.85	2.44	3.11 (2)	137

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

Acknowledgments

The Islamic Azad University, Quchan Branch, Quchan, Iran is gratefully acknowledged for financial support of this research paper.

supplementary crystallographic information

Comment

In continuation of our previous studies of inorganic-organic hybrid materials based on polyoxidometalates (Alizadeh et al., 2008a,b; Nikpour et al., 2009), we report here on the structure of the title compound, [C₆H₁₂N₅O]₃[W₁₂(PO₄)O₃₆]^.6H₂O, (I), as a pseudopolymorph (different number of crystal water molecules; Desiraju, 2003) of [C₆H₁₂N₅O]₃[W₁₂(PO₄)O₃₆]^.5H₂O as reported by us previously (Nikpour et al., 2010).

The structure of (I) consists of one discrete anion [(PO₄)W₁₂O₃₆]^3-, three [C₆H₁₂N₅O]⁺ cations and six water molecules of crystallisation. (Fig. 1). The anion in the title compound is of the well-known α-Keggin type consisting of four groups of W₃O₁₀ units. Each WO₆ octahedron in such a unit shares edges with its neighbours. Four W₃O₁₀ units are linked together via corner-sharing WO₆ octahedra to form a cage with a P atom located in the tetrahedrally surrounded centre. There are four kinds of oxygen atoms in the heteropolyanion, viz. four O atoms (O1c, O5c, O9c, O13c) that are bonded to the P atom and to three W atoms, twelve corner-sharing atoms Oc atom that bridge the different W₃O₁₃ units, twelve edge-sharing atoms Ob that bridge within the W₃O₁₃ units, and twelve terminal oxygen atoms Ot. In the organic cation, the 1H-tetrazole ring and the methylcarbon atom lie approximately in the same plane and the morpholine ring is in a chair configuration. In (I), all bond lengths and angles are normal and comparable with those observed in the pseudopolymorph with 5 crystal water molecules (Nikpour et al., 2010)). The three organic cations in (I) show only minor differences with respect to bond lengths and angles.

The molecular entities are linked together via an extensive network of N—H···O, N—H···N, O—H···O and O—H···N hydrogen bonding interactions (Fig. 2). The charge-compensating cations [C₆H₁₂N₅O]⁺ can be considered as the space-filling structural subunits and are connected to one side of the α-[(PO₄)W₁₂O₃₆]^3- anion by the aforementioned multiple hydrogen-bonding interactions. Since [C₆H₁₂N₅O]⁺ cations lie at one side of the anion, the inorganic anions are well-separated by [C₆H₁₂N₅O]⁺ cations and by additional water molecules of crystallisation.

In recent years, there has been increasing interest in the experimental and theoretical study of water clusters (H₂O)_n because these water assemblies might provide an insight into some of the unexplained properties of bulk water, namely into the processes that occur at the ice-liquid, ice-air, and liquid-air interfaces, and into the nature of water-water and water-solute interactions (Aghabozorg et al. 2010). In the network of (I), six uncoordinated water molecules increase the number of O—H···O hydrogen bonds and thus lead to the formation of (H₂O)_∞ clusters. Indeed, these units were found to act as a 'supramolecular glue' in the aggregation of [C₆H₁₂N₅O]₃[W₁₂(PO₄)O₃₆]^.6H₂O and hence support the consolidation of the three-dimensional network.

Experimental

A solution of ((1H-tetrazole-5-yl)methyl)morpholine (0.14 g, 0.82 mmol) in 30 ml of distilled water was added with vigorous stirring to a solution of α-H₃[(PO₄)W₁₂O₃₆]^.21H₂O (0.50 g, 0.27 mmol) in 25 ml of distilled water. A colorless precipitate was formed after five hours. The solid was filtered off, washed with DMF and dried at room temperature. The precipitate was then re-dissolved in acetonitrile and the solution was cooled to ambient temperature; colorless block-shaped crystals were obtained, filtered off, washed several times with distilled water, and dried in air (yield 30% based on W) and characterized by spectroscopy and X-ray crystallography methods. ¹H NMR in D₂O:d 2.65 (t, 4H, (CH₂)₂N), 3.80 (t,4H, (CH₂)₂O), 4.15 (s, 2H, CH₂-(N(CH₂)₂)).Anal. calcd. for C₁₈H₄₅N₁₅O₄₉PW₁₂:C, 6.19; H, 1.30; N, 6.02; P, 0.90; W, 63.20. Found: C, 6.41; H, 1.41; N, 5.88; P, 0.85; W, 63.00.