supplementary materials


hg5235 scheme

Acta Cryst. (2012). E68, o2711    [ doi:10.1107/S1600536812034940 ]

6,6'-Dimethoxy-2,2'-{[(E,E)-hydrazine-1,2-diylidene]bis(methanylylidene)}diphenol methanol disolvate

N. M. Randell, L. K. Thompson and L. N. Dawe

Abstract top

The title compound, C16H16N2O4·2CH3OH, is a hydrazone in an E geometric arrangement, with an inversion centre at the mid-point of the N-N bond. A symmetry-related pair of six-membered hydrogen-bonded rings [graph-set motif S11(6)] are present for the terminal vanillin-imine moieties. Two lattice methanol solvent molecules are present per formula unit (Z' = 1/2), which form hydrogen-bonded chains along [010] with two orientations due to disorder of the methanol H-atom.

Comment top

The synthesis of this compound was performed because of its intriguing interactions with both transition and lanthanide metals. The ability for the vanillin moieties to bridge multiple metal centers to form polymetallic clusters has potential applications in the fields of molecular magnetics and supramolecular chemistry.

While the previously reported solventless structure (Lu et al. 2011) and the title compound are comprised of two vanillin-imine moieties, in the title compound, these are related by an inversion centre about the N1i—N1 bond (i = 1 - x,2 - y,1 - z). There are two available geometries for the hydrazone functional group, the E and Z isomers. Both this report, and the previously reported structure, feature the E isomer (Figure 1).

There are multiple hydrogen bonding interactions, one intramolecular for the main molecule and one intermolecular hydrogen bonding chain, however, there are no discernable hydrogen bonding interaction between the main molecule and the solvent methanol molecules. The intramolecular hydrogen bond between N1 and H1 forms a stable six-membered hydrogen bound ring with graph set notation S11(6) (one hydrogen bond donor, and one acceptor enclosed in a six-membered ring; Figure 1) (Bernstein et al. 1995, Etter et al. 1990). This interaction was also present in the previous report (Lu et al. 2011). This structural motif would likely provide an energetic barrier to rotation about the C2—C3 bond, which would be required to maximize the number of metals that could be incorporated into a cluster for further study.

A second hydrogen bond interaction is present as a one-dimensional chain of solvent methanol molecules, with graph set notation of C11(2) (Figure 2.) The methanolic protons, H3A and H3B, are disordered, with occupancy of 1/2, and when extended packing diagrams are examined, it can be seen that the hydrogen bonded chains propagate along [0 1 0] (i.e. run parallel to the b axis), with the disorder representing a reversal in the D—H···A orientation.

Related literature top

The synthesis of the title compound was originally reported by Lin et al. (2009); however, in this report, the title compound was obtained from (2Z,6Z,N'2E,N'6E)-N'2,N'6-bis(2-hydroxy-3-methoxybenzylidene)pyridine-2,6-bis(carbohydrazonic) acid (Vadavi et al. 2011). The title compound has been used in the synthesis of first-row transition metal complexes (Zou et al. 2011) and in the synthesis of lanthanide complexes (Davidson et al. 2006). A solvent-free structure of the title compound has been previously reported (Lu et al. 2011) and contains a similar intramolecular hydrogen-bonding motif (Bernstein et al. 1995, Etter et al. 1990) to that reported herein.

Experimental top

DyCl3.H2O (0.06 g; 0.2 mmol) was dissolved in methanol (20 mL). (2Z,6Z,N'2E,N'6E)-N'2,N'6-bis(2-hydroxy-3-methoxybenzylidene)pyridine-2,6-bis(carbohydrazonic) acid (Vadavi et al. 2011) (0.05 g; 0.1 mmol) was added and the solution was refluxed for 3 h. Upon cooling, the resulting solution was gravity filtered and left for slow evaporation at room temperature to yield yellow-orange crystals of the title compound.

Refinement top

With the exception of H3A, H3B and H2, all hydrogen positions were calculated after each cycle of refinement using a riding model, with C—H = 0.93 Å and Uiso(H) = 1.2Ueq(C) for aromatic H atoms, and with C—H = 0.96 Å and Uiso(H) = 1.5Ueq(C) for methyl H atoms. H2 was allowed to refine positionally, with Uiso(H) = 1.5Ueq(O2). The disordered H atoms, H3A and H3B were refined with distance (O3—H) and angle (C5—O3—H) restraints of 0.87 Å and 110° respectively, and with Uiso(H) = 1.5Ueq(O3). H3A and H3B were both assigned an occupancy of 0.5 based on similar residual peak height from examination of difference maps, prior to their introduction.

Computing details top

Data collection: CrystalClear-SM Expert (Rigaku, 2009); cell refinement: CrystalClear-SM Expert (Rigaku, 2009); data reduction: CrystalClear-SM Expert (Rigaku, 2009); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: OLEX2 (Dolomanov et al., 2009); software used to prepare material for publication: OLEX2 (Dolomanov et al., 2009).

Figures top
[Figure 1] Fig. 1. Molecular structure of the title compound at 50% probability ellipsoid level. Symmetry operator i = 1 - x, 2 - y, 1 - z; iv = 1 - x, 1 - y, 1 - z.
[Figure 2] Fig. 2. Packed unit cell of the title compound, highlighting the hydrogen bonding chains which propagate along [0 1 0]. One of the disordered H-atoms is omitted from each methanol molecule.
6,6'-Dimethoxy-2,2'-{[(E,E)-hydrazine-1,2- diylidene]bis(methanylylidene)}diphenol methanol disolvate top
Crystal data top
C16H16N2O4·2CH4OF(000) = 388
Mr = 364.39Dx = 1.282 Mg m3
Monoclinic, P21/cMo Kα radiation, λ = 0.71075 Å
Hall symbol: -P 2ybcCell parameters from 9154 reflections
a = 20.517 (2) Åθ = 3.4–27.6°
b = 4.8374 (5) ŵ = 0.10 mm1
c = 21.366 (3) ÅT = 163 K
β = 153.566 (7)°Irregular, yellow
V = 944.0 (3) Å30.59 × 0.14 × 0.13 mm
Z = 2
Data collection top
Rigaku Saturn70 CCD
diffractometer
1941 independent reflections
Radiation source: fine-focus sealed tube1651 reflections with I > 2σ(I)
Graphite - Rigaku SHINE monochromatorRint = 0.036
Detector resolution: 14.63 pixels mm-1θmax = 26.5°, θmin = 3.4°
ω scansh = 2525
Absorption correction: multi-scan
(REQAB; Jacobson, 1998)
k = 56
Tmin = 0.725, Tmax = 1.000l = 2626
12068 measured reflections
Refinement top
Refinement on F2Primary atom site location: structure-invariant direct methods
Least-squares matrix: fullSecondary atom site location: difference Fourier map
R[F2 > 2σ(F2)] = 0.062Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.194H atoms treated by a mixture of independent and constrained refinement
S = 1.09 w = 1/[σ2(Fo2) + (0.118P)2 + 0.3328P]
where P = (Fo2 + 2Fc2)/3
1941 reflections(Δ/σ)max < 0.001
129 parametersΔρmax = 0.32 e Å3
4 restraintsΔρmin = 0.41 e Å3
Crystal data top
C16H16N2O4·2CH4OV = 944.0 (3) Å3
Mr = 364.39Z = 2
Monoclinic, P21/cMo Kα radiation
a = 20.517 (2) ŵ = 0.10 mm1
b = 4.8374 (5) ÅT = 163 K
c = 21.366 (3) Å0.59 × 0.14 × 0.13 mm
β = 153.566 (7)°
Data collection top
Rigaku Saturn70 CCD
diffractometer
1941 independent reflections
Absorption correction: multi-scan
(REQAB; Jacobson, 1998)
1651 reflections with I > 2σ(I)
Tmin = 0.725, Tmax = 1.000Rint = 0.036
12068 measured reflectionsθmax = 26.5°
Refinement top
R[F2 > 2σ(F2)] = 0.062H atoms treated by a mixture of independent and constrained refinement
wR(F2) = 0.194Δρmax = 0.32 e Å3
S = 1.09Δρmin = 0.41 e Å3
1941 reflectionsAbsolute structure: ?
129 parametersFlack parameter: ?
4 restraintsRogers parameter: ?
Special details top

Geometry. All e.s.d.'s (except the e.s.d. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell e.s.d.'s are taken into account individually in the estimation of e.s.d.'s in distances, angles and torsion angles; correlations between e.s.d.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell e.s.d.'s is used for estimating e.s.d.'s involving l.s. planes.

Refinement. Refinement of F2 against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F2, conventional R-factors R are based on F, with F set to zero for negative F2. The threshold expression of F2 > σ(F2) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F2 are statistically about twice as large as those based on F, and R- factors based on ALL data will be even larger.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top
xyzUiso*/UeqOcc. (<1)
O20.26395 (15)0.6929 (3)0.38898 (14)0.0446 (4)
H20.318 (3)0.797 (6)0.411 (3)0.067*
C30.51958 (19)0.5637 (4)0.61567 (19)0.0321 (4)
C40.6264 (2)0.3959 (4)0.73588 (19)0.0360 (5)
H40.72400.41310.80820.043*
C20.37270 (19)0.5380 (4)0.50753 (18)0.0341 (5)
C10.3337 (2)0.3422 (4)0.52005 (19)0.0357 (5)
C60.4408 (2)0.1796 (4)0.6393 (2)0.0367 (5)
H60.41510.05140.64780.044*
C50.5869 (2)0.2059 (4)0.74696 (19)0.0381 (5)
H50.65800.09490.82650.046*
O10.18781 (15)0.3354 (3)0.40867 (15)0.0490 (5)
N10.46904 (17)0.9117 (3)0.49594 (16)0.0353 (4)
C80.5634 (2)0.7607 (4)0.60529 (19)0.0347 (4)
H80.66190.77720.67960.042*
C70.1407 (2)0.1307 (5)0.4117 (2)0.0498 (6)
H7A0.03600.13640.32530.075*
H7B0.18390.16670.48900.075*
H7C0.17040.04870.42290.075*
O30.0380 (3)0.2477 (5)0.0577 (3)0.0813 (7)
H3A0.032 (10)0.428 (5)0.044 (9)0.122*0.50
H3B0.024 (7)0.138 (13)0.015 (5)0.122*0.50
C90.0339 (3)0.2220 (7)0.1198 (3)0.0704 (8)
H9A0.06610.22280.04780.106*
H9B0.08530.37420.18270.106*
H9C0.07960.05160.17130.106*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
O20.0338 (7)0.0509 (9)0.0391 (8)0.0011 (6)0.0315 (7)0.0087 (6)
C30.0351 (9)0.0337 (10)0.0352 (9)0.0036 (7)0.0323 (8)0.0044 (7)
C40.0330 (9)0.0410 (10)0.0353 (9)0.0003 (7)0.0308 (9)0.0011 (8)
C20.0345 (9)0.0356 (10)0.0340 (9)0.0001 (7)0.0309 (9)0.0006 (7)
C10.0339 (9)0.0396 (10)0.0364 (9)0.0047 (8)0.0318 (9)0.0036 (8)
C60.0442 (10)0.0364 (10)0.0427 (10)0.0035 (8)0.0404 (10)0.0019 (8)
C50.0406 (10)0.0400 (10)0.0367 (9)0.0033 (8)0.0349 (9)0.0035 (8)
O10.0352 (7)0.0593 (10)0.0456 (8)0.0025 (6)0.0354 (7)0.0066 (7)
N10.0399 (8)0.0368 (9)0.0410 (9)0.0055 (7)0.0376 (8)0.0037 (7)
C80.0370 (9)0.0376 (10)0.0389 (9)0.0043 (7)0.0351 (9)0.0050 (8)
C70.0427 (11)0.0598 (14)0.0506 (12)0.0086 (10)0.0422 (11)0.0013 (10)
O30.0841 (14)0.0932 (16)0.0861 (14)0.0099 (12)0.0783 (14)0.0147 (13)
C90.0518 (13)0.098 (2)0.0550 (14)0.0091 (14)0.0472 (13)0.0002 (14)
Geometric parameters (Å, º) top
O2—C21.354 (2)O1—C71.425 (3)
O2—H20.88 (3)N1—C81.281 (3)
C3—C21.402 (3)N1—N1i1.407 (3)
C3—C41.407 (3)C8—H80.9300
C3—C81.456 (3)C7—H7A0.9600
C4—C51.378 (3)C7—H7B0.9600
C4—H40.9300C7—H7C0.9600
C2—C11.412 (3)O3—C91.409 (4)
C1—O11.367 (2)O3—H3A0.89 (2)
C1—C61.383 (3)O3—H3B0.88 (2)
C6—C51.395 (3)C9—H9A0.9600
C6—H60.9300C9—H9B0.9600
C5—H50.9300C9—H9C0.9600
C2—O2—H298.1 (19)C8—N1—N1i113.50 (19)
C2—C3—C4119.54 (17)N1—C8—C3121.36 (17)
C2—C3—C8121.05 (17)N1—C8—H8119.3
C4—C3—C8119.41 (16)C3—C8—H8119.3
C5—C4—C3120.29 (17)O1—C7—H7A109.5
C5—C4—H4119.9O1—C7—H7B109.5
C3—C4—H4119.9H7A—C7—H7B109.5
O2—C2—C3122.92 (17)O1—C7—H7C109.5
O2—C2—C1117.48 (16)H7A—C7—H7C109.5
C3—C2—C1119.59 (17)H7B—C7—H7C109.5
O1—C1—C6125.69 (17)C9—O3—H3A106 (3)
O1—C1—C2114.56 (16)C9—O3—H3B113 (4)
C6—C1—C2119.74 (17)H3A—O3—H3B118 (7)
C1—C6—C5120.61 (17)O3—C9—H9A109.5
C1—C6—H6119.7O3—C9—H9B109.5
C5—C6—H6119.7H9A—C9—H9B109.5
C4—C5—C6120.23 (17)O3—C9—H9C109.5
C4—C5—H5119.9H9A—C9—H9C109.5
C6—C5—H5119.9H9B—C9—H9C109.5
C1—O1—C7117.07 (16)
Symmetry code: (i) x+1, y+2, z+1.
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
O2—H2···N10.88 (3)1.77 (7)2.613 (5)160 (3)
O3—H3A···O3ii0.89 (8)1.91 (7)2.754 (4)157 (9)
O3—H3B···O3iii0.88 (7)1.98 (7)2.715 (4)140 (5)
Symmetry codes: (ii) x, y+1, z; (iii) x, y, z.
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
O2—H2···N10.88 (3)1.77 (7)2.613 (5)160 (3)
O3—H3A···O3i0.89 (8)1.91 (7)2.754 (4)157 (9)
O3—H3B···O3ii0.88 (7)1.98 (7)2.715 (4)140 (5)
Symmetry codes: (i) x, y+1, z; (ii) x, y, z.
Acknowledgements top

We thank NSERC (Canada) for financial support for these studies.

references
References top

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