Bis[μ-N-(2-oxidobenzyl­idene)pyridine-2-carbohydrazidato]bis­[chlorido(methanol-κO)erbium(III)]

In the binuclear title complex, [Er₂(C₁₃H₉N₃O₂)₂Cl₂(CH₃OH)₂], the entire mol­ecule is generated by the application of inversion symmetry. Each Er^III ion is seven-coordinated by two O atoms and one N atom from one N-(2-oxidobenzyl­idene)pyridine-2-carbohydrazidate (L²⁻) ligand, one O atom and one N atom from the symmetry-related L²⁻ ligand, one O atom of a methanol mol­ecule and one chloride anion. The coordination geometry is based on a pseudo-penta­gonal bipyramid. Linear supra­molecular chains along [010] are formed in the crystal packing through O—H⋯Cl hydrogen bonds.

Key indicators

• Single-crystal X-ray study
• T = 128 K
• Mean [sigma](C-C) = 0.006 Å
• R factor = 0.027
• wR factor = 0.059
• Data-to-parameter ratio = 18.7

checkCIF/PLATON results

No syntax errors found



Alert level C
PLAT910_ALERT_3_C Missing # of FCF Reflections Below Th(Min) .....          1
PLAT912_ALERT_4_C Missing # of FCF Reflections Above STh/L=  0.600          8

Alert level G
PLAT005_ALERT_5_G No _iucr_refine_instructions_details in CIF ....          ?
PLAT007_ALERT_5_G Note: Number of Unrefined D-H Atoms ............          1
PLAT232_ALERT_2_G Hirshfeld Test Diff (M-X)  Er1    --  Cl1     ..        5.7 su

   0 ALERT level A = Most likely a serious problem - resolve or explain
   0 ALERT level B = A potentially serious problem, consider carefully
   2 ALERT level C = Check. Ensure it is not caused by an omission or oversight
   3 ALERT level G = General information/check it is not something unexpected

   0 ALERT type 1 CIF construction/syntax error, inconsistent or missing data
   1 ALERT type 2 Indicator that the structure model may be wrong or deficient
   1 ALERT type 3 Indicator that the structure quality may be low
   1 ALERT type 4 Improvement, methodology, query or suggestion
   2 ALERT type 5 Informative message, check

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S1. Comment

The chemistry of coordination complexes supported by salicylaldehyde-2-pyridinecarboxyl-hydrazone (H₂L) and its derivatives has received intensive attention as these form coordination complexes with aesthetically pleasing structures and intriguing magnetic behaviour (Guo et al., 2011a,b). A handful of transition metal complexes based on the H₂L ligand have been prepared (Bai et al., 2005; Wu et al., 2004; Bai et al., 2006; Milway et al., 2003), but no complex containing rare earth elements has been reported to date. Herein, we report the structure of a new dinuclear Er^III complex (Scheme 1). The complex was synthesized by the 2:1:1 reaction of ErCl₃.6H₂O/α-pyridoin/salicylaldehyde thiosemicarbazone under solvothermal conditions. The X-ray analysis reveals that the centrosymmetric complex consists of two Er^III ions, two L^2- ligands, two Cl^- ions and two methanol molecules, Fig. 1 and Table 1. The intermolecular O—H···Cl hydrogen bonds, Table 2, lead to linear supramolecular chains along [010] (Fig. 2).

The remarkable structural feature of the complex is the presence of the in situ formed H₂L ligand, which was proposed to be constructed by the reaction of picolinic acid, hydrazine and salicylaldehyde. The picolinic acid was assumed to be derived from the hydrolysis of α-pyridoin, and hydrazine and salicylaldehyde were believed to be originated from the hydrolysis of salicylaldehyde thiosemicarbazone (Narang & Aggarwal, 1974).

Related literature

For complexes containing salicylaldehyde-2-pyridinecarboxyl-hydrazone and related ligands, see: Guo et al. (2011a,b); Bai et al. (2005, 2006); Wu et al. (2004); Milway et al. (2003). For the mechanism of the hydrolysis of salicylaldehyde thiosemicarbazone, see: Narang & Aggarwal (1974).

S2. Experimental

A mixture of ErCl₃.6H₂O (0.0762 g, 0.2 mmol), α-pyridoin (0.0214 g, 0.1 mmol), salicylaldehyde thiosemicarbazone (0.0390 g, 0.2 mmol) and CH₃OH (2 ml) was sealed in a 6 ml Pyrex-tube. The tube was heated at 393 K for 3 days under autogenous pressure. Cooling of the resultant solution to room temperature gave yellow crystals. The crystals were collected by filtration, washed with CH₃OH (2 ml) and dried in air.

S3. Refinement

The H atoms were placed in calculated positions with O—H = 0.95 Å and C—H = 0.95–0.98 Å, and with U_iso(H) = 1.2–1.5U_eq(C, O).

Computing details

Data collection: SMART (Bruker, 2000); cell refinement: SAINT (Bruker, 2000); data reduction: SAINT (Bruker, 2000); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: SHELXTL (Sheldrick, 2008); software used to prepare material for publication: SHELXTL (Sheldrick, 2008).

Figures

	Fig. 1. The molecular structure of the title compound, with atom labels and 30% probability displacement ellipsoids. The H atoms have been omitted for clarity.
	Fig. 2. View of the linear supramolecular chain along [010] with the O—H···Cl hydrogen bonds shown as dashed lines.

Bis[µ-N-(2-oxidobenzylidene)pyridine-2- carbohydrazidato]bis[chlorido(methanol-κO)erbium(III)]

Crystal data

[Er2(C13H9N3O2)2Cl2(CH4O)2]	F(000) = 908
Mr = 947.97	Dx = 2.089 Mg m^−3
Monoclinic, P21/c	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ybc	Cell parameters from 4466 reflections
a = 9.5810 (4) Å	θ = 2.7–28.1°
b = 7.0906 (3) Å	µ = 5.76 mm^−1
c = 22.3504 (8) Å	T = 128 K
β = 96.920 (3)°	Block, yellow
V = 1507.31 (10) Å^3	0.15 × 0.13 × 0.12 mm
Z = 2

Data collection

Bruker SMART CCD diffractometer	3732 independent reflections
Radiation source: fine-focus sealed tube	2931 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.040
φ scans and ω scans	θmax = 28.3°, θmin = 2.1°
Absorption correction: multi-scan (SADABS; Bruker 2000)	h = −12→11
Tmin = 0.479, Tmax = 0.545	k = −9→9
14182 measured reflections	l = −29→29

Refinement

Refinement on F^2	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F^2 > 2σ(F^2)] = 0.027	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.059	H-atom parameters constrained
S = 0.99	w = 1/[σ^2(Fo^2) + (0.0299P)^2] where P = (Fo^2 + 2Fc^2)/3
3732 reflections	(Δ/σ)max = 0.004
200 parameters	Δρmax = 1.25 e Å^−3
0 restraints	Δρmin = −0.71 e Å^−3

Special details

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 (Ų)

	x	y	z	Uiso*/Ueq
Er1	0.372121 (17)	0.91591 (3)	0.432040 (7)	0.02740 (6)
O2	0.5836 (3)	1.0615 (4)	0.46548 (11)	0.0323 (6)
O3	0.2988 (3)	1.2290 (5)	0.42893 (15)	0.0526 (8)
H7	0.3591	1.3150	0.4521	0.063*
C5	0.6425 (4)	1.0757 (5)	0.36561 (16)	0.0289 (8)
Cl1	0.48595 (13)	0.58790 (16)	0.42195 (5)	0.0476 (3)
N1	0.5108 (3)	1.0104 (5)	0.34970 (14)	0.0282 (7)
O1	0.1993 (3)	0.8698 (4)	0.36235 (12)	0.0386 (7)
C14	0.0511 (4)	0.7742 (6)	0.46482 (18)	0.0366 (9)
H14	−0.0122	0.7498	0.4935	0.044*
C8	0.0727 (4)	0.7952 (5)	0.35398 (17)	0.0306 (9)
C6	0.6814 (4)	1.1036 (5)	0.43082 (17)	0.0287 (8)
N3	0.1753 (3)	0.8294 (5)	0.48577 (14)	0.0308 (7)
N4	0.8066 (3)	1.1581 (5)	0.45048 (14)	0.0344 (8)
C1	0.4695 (4)	0.9753 (6)	0.29156 (18)	0.0343 (9)
H1	0.3765	0.9309	0.2802	0.041*
C4	0.7340 (4)	1.1077 (6)	0.32293 (18)	0.0373 (10)
H4	0.8257	1.1559	0.3347	0.045*
C10	−0.1348 (5)	0.6619 (7)	0.3905 (2)	0.0435 (11)
H10	−0.1858	0.6313	0.4230	0.052*
C12	−0.1223 (5)	0.6715 (7)	0.2860 (2)	0.0440 (11)
H12	−0.1625	0.6447	0.2459	0.053*
C9	−0.0018 (4)	0.7457 (6)	0.40305 (17)	0.0332 (8)
C3	0.6899 (5)	1.0688 (6)	0.26356 (19)	0.0413 (10)
H3	0.7513	1.0886	0.2338	0.050*
C13	0.0074 (4)	0.7590 (6)	0.29574 (18)	0.0366 (9)
H13	0.0532	0.7954	0.2621	0.044*
C2	0.5561 (5)	1.0008 (7)	0.24736 (18)	0.0393 (10)
H2	0.5241	0.9721	0.2065	0.047*
C11	−0.1934 (5)	0.6230 (7)	0.3332 (2)	0.0499 (12)
H11	−0.2825	0.5629	0.3262	0.060*
C7	0.1756 (6)	1.3080 (8)	0.3970 (3)	0.0722 (17)
H7A	0.1078	1.2075	0.3850	0.108*
H7B	0.2000	1.3728	0.3609	0.108*
H7C	0.1341	1.3985	0.4229	0.108*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Er1	0.02276 (9)	0.03156 (11)	0.02796 (10)	−0.00645 (8)	0.00334 (6)	−0.00213 (8)
O2	0.0269 (13)	0.0435 (18)	0.0273 (14)	−0.0087 (12)	0.0062 (10)	−0.0013 (12)
O3	0.0461 (19)	0.0366 (19)	0.073 (2)	0.0010 (15)	−0.0021 (15)	−0.0050 (17)
C5	0.0294 (18)	0.027 (2)	0.0304 (19)	−0.0045 (16)	0.0041 (15)	0.0008 (17)
Cl1	0.0544 (7)	0.0371 (6)	0.0535 (7)	0.0029 (5)	0.0145 (5)	0.0048 (5)
N1	0.0286 (16)	0.0276 (17)	0.0285 (17)	−0.0043 (13)	0.0038 (13)	−0.0008 (14)
O1	0.0266 (14)	0.054 (2)	0.0347 (16)	−0.0102 (13)	0.0012 (11)	−0.0015 (13)
C14	0.0283 (19)	0.042 (3)	0.040 (2)	−0.0070 (18)	0.0065 (16)	−0.003 (2)
C8	0.0251 (18)	0.032 (2)	0.034 (2)	0.0003 (15)	−0.0017 (15)	−0.0056 (17)
C6	0.0285 (19)	0.031 (2)	0.0273 (19)	−0.0042 (16)	0.0040 (14)	−0.0006 (16)
N3	0.0264 (16)	0.0361 (19)	0.0299 (17)	−0.0075 (14)	0.0033 (13)	−0.0026 (14)
N4	0.0288 (17)	0.046 (2)	0.0289 (18)	−0.0093 (15)	0.0066 (14)	−0.0029 (15)
C1	0.035 (2)	0.038 (3)	0.029 (2)	−0.0038 (17)	0.0004 (16)	0.0010 (18)
C4	0.032 (2)	0.045 (3)	0.035 (2)	−0.0083 (19)	0.0059 (16)	0.003 (2)
C10	0.035 (2)	0.048 (3)	0.046 (3)	−0.012 (2)	0.0013 (19)	−0.002 (2)
C12	0.036 (2)	0.047 (3)	0.046 (3)	−0.003 (2)	−0.0083 (19)	−0.011 (2)
C9	0.0263 (18)	0.036 (2)	0.036 (2)	−0.0036 (18)	0.0003 (15)	−0.0054 (19)
C3	0.041 (2)	0.049 (3)	0.036 (2)	0.002 (2)	0.0135 (18)	0.005 (2)
C13	0.033 (2)	0.040 (2)	0.036 (2)	0.0003 (19)	0.0012 (16)	−0.006 (2)
C2	0.044 (2)	0.047 (3)	0.026 (2)	0.000 (2)	−0.0002 (18)	0.0001 (19)
C11	0.037 (2)	0.050 (3)	0.060 (3)	−0.018 (2)	−0.007 (2)	−0.005 (2)
C7	0.069 (4)	0.058 (4)	0.088 (4)	0.019 (3)	0.003 (3)	0.013 (3)

Geometric parameters (Å, º)

Er1—O1	2.157 (3)	C6—N4	1.286 (5)
Er1—O2^i	2.284 (3)	N3—N4^i	1.417 (4)
Er1—O2	2.316 (3)	N4—N3^i	1.417 (4)
Er1—O3	2.327 (3)	C1—C2	1.376 (6)
Er1—N3	2.433 (3)	C1—H1	0.9500
Er1—N1	2.488 (3)	C4—C3	1.371 (6)
Er1—Cl1	2.5901 (12)	C4—H4	0.9500
O2—C6	1.320 (4)	C10—C11	1.362 (6)
O2—Er1^i	2.284 (3)	C10—C9	1.403 (5)
O3—C7	1.419 (6)	C10—H10	0.9500
O3—H7	0.9500	C12—C11	1.369 (7)
C5—N1	1.351 (5)	C12—C13	1.382 (6)
C5—C4	1.390 (5)	C12—H12	0.9500
C5—C6	1.474 (5)	C3—C2	1.377 (6)
N1—C1	1.335 (5)	C3—H3	0.9500
O1—C8	1.316 (4)	C13—H13	0.9500
C14—N3	1.286 (5)	C2—H2	0.9500
C14—C9	1.427 (5)	C11—H11	0.9500
C14—H14	0.9500	C7—H7A	0.9800
C8—C13	1.398 (5)	C7—H7B	0.9800
C8—C9	1.423 (5)	C7—H7C	0.9800
O1—Er1—O2^i	140.21 (10)	O1—C8—C13	120.5 (4)
O1—Er1—O2	149.99 (10)	O1—C8—C9	122.0 (3)
O2^i—Er1—O2	66.16 (10)	C13—C8—C9	117.5 (3)
O1—Er1—O3	85.42 (12)	N4—C6—O2	124.5 (3)
O2^i—Er1—O3	88.97 (11)	N4—C6—C5	119.5 (3)
O2—Er1—O3	80.42 (11)	O2—C6—C5	115.9 (3)
O1—Er1—N3	75.24 (10)	C14—N3—N4^i	112.4 (3)
O2^i—Er1—N3	65.42 (10)	C14—N3—Er1	129.4 (3)
O2—Er1—N3	130.77 (10)	N4^i—N3—Er1	118.2 (2)
O3—Er1—N3	90.34 (11)	C6—N4—N3^i	111.0 (3)
O1—Er1—N1	86.47 (10)	N1—C1—C2	122.7 (4)
O2^i—Er1—N1	132.20 (10)	N1—C1—H1	118.6
O2—Er1—N1	66.06 (9)	C2—C1—H1	118.6
O3—Er1—N1	84.69 (11)	C3—C4—C5	119.0 (4)
N3—Er1—N1	161.38 (11)	C3—C4—H4	120.5
O1—Er1—Cl1	95.50 (9)	C5—C4—H4	120.5
O2^i—Er1—Cl1	96.94 (7)	C11—C10—C9	122.4 (4)
O2—Er1—Cl1	93.86 (7)	C11—C10—H10	118.8
O3—Er1—Cl1	169.37 (9)	C9—C10—H10	118.8
N3—Er1—Cl1	100.15 (8)	C11—C12—C13	120.8 (4)
N1—Er1—Cl1	84.80 (8)	C11—C12—H12	119.6
O1—Er1—Er1^i	167.32 (8)	C13—C12—H12	119.6
O2^i—Er1—Er1^i	33.34 (6)	C10—C9—C8	118.5 (4)
O2—Er1—Er1^i	32.82 (6)	C10—C9—C14	117.5 (4)
O3—Er1—Er1^i	83.65 (8)	C8—C9—C14	123.9 (3)
N3—Er1—Er1^i	98.39 (7)	C4—C3—C2	119.6 (4)
N1—Er1—Er1^i	98.87 (7)	C4—C3—H3	120.2
Cl1—Er1—Er1^i	96.43 (3)	C2—C3—H3	120.2
C6—O2—Er1^i	120.9 (2)	C12—C13—C8	121.5 (4)
C6—O2—Er1	124.5 (2)	C12—C13—H13	119.3
Er1^i—O2—Er1	113.84 (10)	C8—C13—H13	119.3
C7—O3—Er1	128.4 (3)	C1—C2—C3	118.7 (4)
C7—O3—H7	115.8	C1—C2—H2	120.7
Er1—O3—H7	115.8	C3—C2—H2	120.7
N1—C5—C4	121.5 (4)	C10—C11—C12	119.2 (4)
N1—C5—C6	115.0 (3)	C10—C11—H11	120.4
C4—C5—C6	123.5 (3)	C12—C11—H11	120.4
C1—N1—C5	118.5 (3)	O3—C7—H7A	109.5
C1—N1—Er1	123.2 (3)	O3—C7—H7B	109.5
C5—N1—Er1	117.6 (2)	H7A—C7—H7B	109.5
C8—O1—Er1	141.0 (2)	O3—C7—H7C	109.5
N3—C14—C9	126.9 (4)	H7A—C7—H7C	109.5
N3—C14—H14	116.5	H7B—C7—H7C	109.5
C9—C14—H14	116.5

Symmetry code: (i) −x+1, −y+2, −z+1.

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
O3—H7···Cl1^ii	0.95	2.42	3.128 (4)	131

Symmetry code: (ii) x, y+1, z.