Dibromido{2-[1-(cyclo­propyl­imino)­eth­yl]pyridine}­zinc(II)

In the title compound, [ZnBr₂(C₁₀H₁₂N₂)], the Zn²⁺ ion is coordinated by the N,N'-bidentate Schiff base ligand and two bromode ions in a distorted tetra­hedral arrangement. The dihedral angle between the pyridine and the cyclo­propyl rings is 95.4 (8)°.

Key indicators

• Single-crystal X-ray study
• T = 298 K
• Mean [sigma](C-C) = 0.019 Å
• R factor = 0.063
• wR factor = 0.165
• Data-to-parameter ratio = 17.6

checkCIF/PLATON results

No syntax errors found



Alert level B
PLAT341_ALERT_3_B Low Bond Precision on  C-C Bonds (x 1000) Ang ..         19

Alert level C
PLAT911_ALERT_3_C Missing # FCF Refl Between THmin & STh/L=  0.600          2
PLAT915_ALERT_3_C Low Friedel Pair Coverage ......................      71.62 Perc.
PLAT125_ALERT_4_C No _symmetry_space_group_name_Hall Given .......          ?
PLAT234_ALERT_4_C Large Hirshfeld Difference C1     --  C2      ..       0.16 Ang.

Alert level G
REFLT03_ALERT_4_G Please check that the estimate of the number of Friedel pairs is
            correct. If it is not, please give the correct count in the
            _publ_section_exptl_refinement section of the submitted CIF.
           From the CIF: _diffrn_reflns_theta_max           27.00
           From the CIF: _reflns_number_total               2408
           Count of symmetry unique reflns         1451
           Completeness (_total/calc)            165.95%
           TEST3: Check Friedels for noncentro structure
           Estimate of Friedel pairs measured       957
           Fraction of Friedel pairs measured     0.660
           Are heavy atom types Z>Si present        yes

   0 ALERT level A = In general: serious problem
   1 ALERT level B = Potentially serious problem
   4 ALERT level C = Check and explain
   1 ALERT level G = General alerts; check

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

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S1. Comment

Schiff bases have often been used as chelating ligands in coordination chemistry (Hamaker et al., 2010; Wang et al., 2010; Mirkhani et al., 2010; Liu & Yang, 2009). We report here the crystal structure of the title new zinc complex with the chelating Schiff base ligand cyclopropyl-(1-pyridin-2-ylethylidene)amine.

The Zn atom in the complex is four-coordinated by one pyridine N and one imine N atoms of the Schiff base ligand, and by two bromide atoms, forming a tetrahedral geometry (Fig. 1). The dihedral angle between the pyridine and the cyclopropyl rings is 95.4 (8)°. The bond lengths (Table 1) related to the Zn atom are comparable to those observed in similar zinc complexes (Zakrzewski & Lingafelter, 1970; Gourbatsis et al., 1999; Merino et al., 2001; Majumder et al., 2006).

Related literature

For background to Schiff bases as chelating ligands, see: Hamaker et al. (2010); Wang et al. (2010); Mirkhani et al. (2010); Liu & Yang (2009). For similar zinc complexes, see: Zakrzewski & Lingafelter (1970); Gourbatsis et al. (1999); Merino et al. (2001); Majumder et al. (2006).

S2. Experimental

2-Acetylpyridine (0.1 mmol, 12.1 mg) and cyclopropylamine (0.1 mmol, 5.7 mg) were mixed and stirred in methanol (10 ml) for 30 min. Then a methanol solution (5 ml) of zinc bromide (0.1 mmol, 22.5 mg) was added to the mixture. The final mixture was stirred for another 30 min to give a colourless solution. Colourless blocks of (I) were obtained by slow evaporation of the solution at room temperature.

S3. Refinement

H atoms were positioned geometrically (C—H = 0.93–0.98 Å) and refined using a riding model, with with U_iso(H) = 1.2 or 1.5U_eq(C). A rotating group model was used for the methyl group.

Computing details

Data collection: APEX2 (Bruker, 2004); cell refinement: SAINT (Bruker, 2004); data reduction: SAINT (Bruker, 2004); 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 complex, showing 30% probability displacement ellipsoids.

Dibromido{2-[1-(cyclopropylimino)ethyl]pyridine}zinc(II)

Crystal data

[ZnBr2(C10H12N2)]	F(000) = 372
Mr = 385.41	Dx = 1.978 Mg m^−3
Monoclinic, P21	Mo Kα radiation, λ = 0.71073 Å
a = 7.029 (3) Å	Cell parameters from 1405 reflections
b = 14.090 (3) Å	θ = 2.8–25.0°
c = 7.037 (2) Å	µ = 8.04 mm^−1
β = 111.820 (3)°	T = 298 K
V = 647.0 (4) Å^3	Block, colourless
Z = 2	0.23 × 0.23 × 0.21 mm

Data collection

Bruker APEXII CCD diffractometer	2408 independent reflections
Radiation source: fine-focus sealed tube	1708 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.104
ω scans	θmax = 27.0°, θmin = 2.9°
Absorption correction: multi-scan (SADABS; Sheldrick, 2004)	h = −8→8
Tmin = 0.259, Tmax = 0.283	k = −18→17
4060 measured reflections	l = −8→8

Refinement

Refinement on F^2	Secondary atom site location: difference Fourier map
Least-squares matrix: full	Hydrogen site location: inferred from neighbouring sites
R[F^2 > 2σ(F^2)] = 0.063	H-atom parameters constrained
wR(F^2) = 0.165	w = 1/[σ^2(Fo^2) + (0.0966P)^2] where P = (Fo^2 + 2Fc^2)/3
S = 0.95	(Δ/σ)max < 0.001
2408 reflections	Δρmax = 0.96 e Å^−3
137 parameters	Δρmin = −1.09 e Å^−3
1 restraint	Absolute structure: Flack (1983), 957 Friedel pairs
Primary atom site location: structure-invariant direct methods	Absolute structure parameter: −0.05 (3)

Special details

Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds 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 > 2sigma(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
Zn1	0.01583 (18)	0.10050 (8)	0.5412 (2)	0.0380 (3)
Br1	−0.0650 (2)	−0.05302 (9)	0.6175 (2)	0.0601 (4)
Br2	0.0576 (2)	0.12235 (9)	0.2262 (2)	0.0559 (4)
N1	−0.1663 (14)	0.2047 (7)	0.5832 (15)	0.040 (2)
N2	0.2313 (14)	0.1748 (7)	0.7783 (14)	0.036 (2)
C1	−0.3710 (18)	0.2147 (10)	0.491 (2)	0.050 (3)
H1	−0.4447	0.1674	0.4022	0.060*
C2	−0.477 (2)	0.2918 (10)	0.524 (2)	0.053 (3)
H2	−0.6184	0.2965	0.4582	0.064*
C3	−0.369 (2)	0.3597 (10)	0.652 (2)	0.057 (4)
H3	−0.4351	0.4134	0.6742	0.069*
C4	−0.158 (2)	0.3503 (9)	0.753 (2)	0.047 (3)
H4	−0.0833	0.3966	0.8450	0.056*
C5	−0.0622 (16)	0.2727 (8)	0.7166 (16)	0.034 (2)
C6	0.1628 (17)	0.2531 (8)	0.8195 (16)	0.036 (2)
C7	0.288 (2)	0.3276 (9)	0.968 (2)	0.058 (4)
H7A	0.2300	0.3390	1.0702	0.087*
H7B	0.2870	0.3854	0.8960	0.087*
H7C	0.4265	0.3057	1.0337	0.087*
C8	0.4414 (17)	0.1441 (9)	0.8788 (19)	0.044 (3)
H8	0.5438	0.1939	0.9385	0.053*
C9	0.471 (2)	0.0526 (10)	0.995 (2)	0.051 (3)
H9A	0.3501	0.0188	0.9917	0.061*
H9B	0.5889	0.0474	1.1220	0.061*
C10	0.511 (2)	0.0589 (11)	0.799 (2)	0.058 (4)
H10A	0.6518	0.0572	0.8084	0.070*
H10B	0.4131	0.0285	0.6781	0.070*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Zn1	0.0393 (6)	0.0335 (7)	0.0441 (7)	−0.0027 (6)	0.0189 (5)	−0.0084 (6)
Br1	0.0749 (9)	0.0420 (7)	0.0784 (10)	−0.0192 (7)	0.0460 (8)	−0.0117 (7)
Br2	0.0672 (8)	0.0607 (9)	0.0464 (7)	−0.0071 (6)	0.0287 (7)	−0.0038 (6)
N1	0.039 (5)	0.039 (6)	0.039 (5)	0.000 (4)	0.010 (4)	−0.005 (4)
N2	0.040 (5)	0.037 (5)	0.029 (5)	0.004 (4)	0.011 (4)	0.009 (4)
C1	0.043 (7)	0.061 (8)	0.045 (7)	0.001 (6)	0.016 (6)	0.001 (6)
C2	0.056 (8)	0.056 (8)	0.056 (8)	0.029 (7)	0.030 (7)	0.009 (7)
C3	0.069 (9)	0.045 (8)	0.066 (9)	0.028 (7)	0.035 (8)	0.013 (7)
C4	0.066 (8)	0.034 (6)	0.045 (7)	0.006 (6)	0.026 (7)	0.001 (5)
C5	0.035 (6)	0.038 (6)	0.028 (5)	0.003 (5)	0.009 (5)	0.009 (5)
C6	0.051 (7)	0.031 (6)	0.030 (6)	−0.002 (5)	0.020 (5)	0.001 (4)
C7	0.065 (9)	0.041 (8)	0.061 (9)	−0.007 (6)	0.016 (8)	−0.014 (6)
C8	0.032 (6)	0.043 (7)	0.052 (7)	0.002 (5)	0.009 (5)	0.001 (6)
C9	0.052 (8)	0.047 (7)	0.054 (7)	0.012 (6)	0.019 (7)	0.015 (6)
C10	0.046 (7)	0.079 (10)	0.047 (7)	0.018 (7)	0.015 (6)	0.007 (7)

Geometric parameters (Å, º)

Zn1—N1	2.041 (9)	C4—H4	0.9300
Zn1—N2	2.073 (10)	C5—C6	1.500 (15)
Zn1—Br1	2.3488 (18)	C6—C7	1.514 (16)
Zn1—Br2	2.3616 (19)	C7—H7A	0.9600
N1—C1	1.348 (15)	C7—H7B	0.9600
N1—C5	1.350 (15)	C7—H7C	0.9600
N2—C6	1.279 (15)	C8—C10	1.48 (2)
N2—C8	1.446 (14)	C8—C9	1.498 (18)
C1—C2	1.383 (18)	C8—H8	0.9800
C1—H1	0.9300	C9—C10	1.506 (19)
C2—C3	1.34 (2)	C9—H9A	0.9700
C2—H2	0.9300	C9—H9B	0.9700
C3—C4	1.392 (19)	C10—H10A	0.9700
C3—H3	0.9300	C10—H10B	0.9700
C4—C5	1.358 (17)
N1—Zn1—N2	80.2 (4)	N2—C6—C5	117.9 (10)
N1—Zn1—Br1	114.3 (3)	N2—C6—C7	125.7 (11)
N2—Zn1—Br1	116.6 (3)	C5—C6—C7	116.4 (10)
N1—Zn1—Br2	110.2 (3)	C6—C7—H7A	109.5
N2—Zn1—Br2	112.4 (3)	C6—C7—H7B	109.5
Br1—Zn1—Br2	117.36 (7)	H7A—C7—H7B	109.5
C1—N1—C5	117.7 (10)	C6—C7—H7C	109.5
C1—N1—Zn1	128.4 (8)	H7A—C7—H7C	109.5
C5—N1—Zn1	113.8 (7)	H7B—C7—H7C	109.5
C6—N2—C8	123.3 (11)	N2—C8—C10	118.4 (11)
C6—N2—Zn1	113.2 (7)	N2—C8—C9	115.8 (10)
C8—N2—Zn1	123.4 (8)	C10—C8—C9	60.7 (9)
N1—C1—C2	123.2 (13)	N2—C8—H8	116.7
N1—C1—H1	118.4	C10—C8—H8	116.7
C2—C1—H1	118.4	C9—C8—H8	116.7
C3—C2—C1	117.8 (12)	C8—C9—C10	59.1 (9)
C3—C2—H2	121.1	C8—C9—H9A	117.9
C1—C2—H2	121.1	C10—C9—H9A	117.9
C2—C3—C4	120.3 (12)	C8—C9—H9B	117.9
C2—C3—H3	119.8	C10—C9—H9B	117.9
C4—C3—H3	119.8	H9A—C9—H9B	115.0
C5—C4—C3	119.3 (12)	C8—C10—C9	60.2 (8)
C5—C4—H4	120.4	C8—C10—H10A	117.8
C3—C4—H4	120.4	C9—C10—H10A	117.8
N1—C5—C4	121.6 (10)	C8—C10—H10B	117.8
N1—C5—C6	114.0 (10)	C9—C10—H10B	117.8
C4—C5—C6	124.3 (11)	H10A—C10—H10B	114.9