Dichloridobis(pyridine-3-carbaldehyde-κN)zinc(II)

In the title compound, [ZnCl₂(C₆H₅NO)₂], the Zn^II atom lies on a mirror plane, and is coordinated by two N atoms from two pyridine-3-carbaldehyde ligands and two Cl ligands in a distorted tetra­hedral geometry. The packing is governed by inter­molecular C—H...O hydrogen-bonding inter­actions.

Key indicators

• Single-crystal X-ray study
• T = 296 K
• Mean [sigma](C-C) = 0.003 Å
• R factor = 0.022
• wR factor = 0.061
• Data-to-parameter ratio = 18.0

checkCIF/PLATON results

No syntax errors found



Alert level C
PLAT232_ALERT_2_C Hirshfeld Test Diff (M-X)  Zn1    -   Cl2     ..       5.06 su
PLAT480_ALERT_4_C Long H...A H-Bond Reported H4     ..  O1      ..       2.66 Ang.

Alert level G
PLAT794_ALERT_5_G Check Predicted Bond Valency for Zn1         (2)       1.99

   0 ALERT level A = In general: serious problem
   0 ALERT level B = Potentially serious problem
   2 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
   1 ALERT type 2 Indicator that the structure model may be wrong or deficient
   0 ALERT type 3 Indicator that the structure quality may be low
   1 ALERT type 4 Improvement, methodology, query or suggestion
   1 ALERT type 5 Informative message, check

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S1. Comment

Coordination compounds of the type ZnL₂Cl₂ (L = 2-NH₂py, 4-CNpy, 4-CH₃py, 4-CH₃COpy,3-NH₂COpy, etc (py = pyridine)) have been previously prepared and studied by several groups (Qin et al., 1999; Steffen & Palenik, 1977; Lynton & Sears, 1971; Ide et al., 2002). In this paper, we report the crystal structure of the new mononuclear zinc complex Zn(3-CHOpy)₂Cl₂ (where 3-CHOpy is 3-pyridinecarboxaldehyde or nicotinaldehyde).

As illustrated in Fig. 1, the Zn^II centre lies on a symmetry plane, defined by the zinc atom and the two chlorine atoms. The zinc center is coordinated to two N atoms from two 3-pyridinecarboxaldehyde ligands and two Cl atoms, and displays a distorted tetrahedral geometry. In the packing, C—H···O hydrogen bonding interactions (Table 1) stabilize the structural components (Fig. 2).

Related literature

Similar complexes have been previously prepared and studied by: Ide et al. (2002); Lynton & Sears (1971); Qin et al. (1999); Steffen & Palenik (1977).

S2. Experimental

The title compound was prepared by the addition of ZnCl₂ (1.0 mmol) to an ethanol solution (20 ml) of pyridine-3-carbalehyde (nicotinaldehyde, 2.0 mmol). The mixture was stirred at 80°C for 2 h and filtered. Colorless prismatic single crystals were obtained from the filtrate upon slow evaporation of the solvent over several days.

S3. Refinement

All H atoms on aromatic rings were placed in calculated positions (C—H = 0.93 Å) and were refined using a riding model with U_iso(H) = 1.2U_eq(C).

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, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: XP in SHELXTL (Bruker, 2004); software used to prepare material for publication: SHELXTL (Bruker, 2004).

Figures

	Fig. 1. The molecular structure of the title complex, showing 50% probability displacement ellipsoids. Unlabelled atoms are related to the labelled atoms by the symmetry operator (x, 1.5 - y, z).
	Fig. 2. Packing diagram of the title complex, viewed along the a axis. Dashed lines indicate the C—H···O hydrogen bonds.

Dichloridobis(pyridine-3-carbaldehyde-κN)zinc(II)

Crystal data

[ZnCl2(C6H5NO)2]	F(000) = 704
Mr = 350.49	Dx = 1.683 Mg m^−3
Orthorhombic, Pnma	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ac 2n	Cell parameters from 1650 reflections
a = 5.8445 (1) Å	θ = 1.4–28.0°
b = 19.2032 (3) Å	µ = 2.16 mm^−1
c = 12.3216 (2) Å	T = 296 K
V = 1382.89 (4) Å^3	Prismatic, colourless
Z = 4	0.20 × 0.18 × 0.18 mm

Data collection

Bruker APEXII area-detector diffractometer	1639 independent reflections
Radiation source: fine-focus sealed tube	1412 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.027
ϕ and ω scans	θmax = 27.5°, θmin = 2.0°
Absorption correction: multi-scan (SADABS; Sheldrick, 1996)	h = −7→7
Tmin = 0.659, Tmax = 0.682	k = −24→23
11915 measured reflections	l = −14→16

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)] = 0.022	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.061	H-atom parameters constrained
S = 1.05	w = 1/[σ^2(Fo^2) + (0.0316P)^2 + 0.3618P] where P = (Fo^2 + 2Fc^2)/3
1639 reflections	(Δ/σ)max < 0.001
91 parameters	Δρmax = 0.24 e Å^−3
0 restraints	Δρmin = −0.26 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
C1	0.4874 (3)	0.65200 (8)	0.05903 (13)	0.0386 (4)
H1	0.4698	0.6765	0.1236	0.046*
C2	0.6525 (3)	0.60094 (9)	0.05413 (15)	0.0420 (4)
C3	0.6773 (3)	0.56404 (9)	−0.04233 (17)	0.0515 (5)
H3	0.7865	0.5290	−0.0483	0.062*
C4	0.5380 (4)	0.58012 (9)	−0.12864 (15)	0.0516 (5)
H4	0.5512	0.5560	−0.1938	0.062*
C5	0.3783 (3)	0.63254 (9)	−0.11717 (14)	0.0450 (4)
H5	0.2860	0.6436	−0.1762	0.054*
C6	0.7926 (3)	0.58667 (10)	0.15072 (16)	0.0542 (5)
H6	0.7659	0.6133	0.2125	0.065*
Cl1	−0.12237 (11)	0.7500	−0.14568 (5)	0.05127 (17)
Cl2	0.00885 (11)	0.7500	0.15928 (5)	0.05020 (17)
N1	0.3506 (2)	0.66815 (7)	−0.02492 (11)	0.0368 (3)
O1	0.9395 (3)	0.54290 (8)	0.15522 (14)	0.0800 (5)
Zn1	0.12503 (4)	0.7500	−0.01246 (2)	0.03558 (10)

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
C1	0.0421 (9)	0.0379 (9)	0.0360 (8)	0.0006 (7)	−0.0002 (7)	−0.0014 (6)
C2	0.0414 (9)	0.0367 (8)	0.0479 (9)	0.0022 (7)	0.0022 (7)	0.0041 (7)
C3	0.0547 (11)	0.0388 (9)	0.0610 (11)	0.0089 (8)	0.0137 (9)	−0.0008 (8)
C4	0.0683 (12)	0.0435 (10)	0.0429 (10)	0.0012 (9)	0.0087 (9)	−0.0087 (8)
C5	0.0541 (11)	0.0441 (9)	0.0369 (8)	−0.0041 (8)	−0.0010 (7)	−0.0015 (7)
C6	0.0513 (11)	0.0511 (11)	0.0601 (11)	0.0052 (9)	−0.0048 (9)	0.0071 (9)
Cl1	0.0436 (4)	0.0672 (4)	0.0430 (3)	0.000	−0.0112 (3)	0.000
Cl2	0.0504 (4)	0.0647 (4)	0.0355 (3)	0.000	0.0057 (3)	0.000
N1	0.0385 (7)	0.0361 (7)	0.0359 (7)	0.0005 (6)	0.0002 (5)	−0.0009 (5)
O1	0.0728 (10)	0.0789 (11)	0.0884 (12)	0.0346 (9)	−0.0138 (9)	0.0078 (9)
Zn1	0.03358 (17)	0.03874 (16)	0.03444 (15)	0.000	−0.00213 (10)	0.000

Geometric parameters (Å, º)

C1—N1	1.344 (2)	C5—N1	1.336 (2)
C1—C2	1.377 (2)	C5—H5	0.9300
C1—H1	0.9300	C6—O1	1.203 (2)
C2—C3	1.391 (3)	C6—H6	0.9300
C2—C6	1.471 (3)	Cl1—Zn1	2.1876 (7)
C3—C4	1.374 (3)	Cl2—Zn1	2.2223 (6)
C3—H3	0.9300	N1—Zn1	2.0571 (14)
C4—C5	1.380 (3)	Zn1—N1^i	2.0571 (14)
C4—H4	0.9300
N1—C1—C2	123.20 (15)	C4—C5—H5	118.6
N1—C1—H1	118.4	O1—C6—C2	124.41 (19)
C2—C1—H1	118.4	O1—C6—H6	117.8
C1—C2—C3	118.24 (17)	C2—C6—H6	117.8
C1—C2—C6	119.17 (17)	C5—N1—C1	117.67 (15)
C3—C2—C6	122.58 (17)	C5—N1—Zn1	122.16 (12)
C4—C3—C2	119.00 (17)	C1—N1—Zn1	120.02 (11)
C4—C3—H3	120.5	N1^i—Zn1—N1	99.65 (8)
C2—C3—H3	120.5	N1^i—Zn1—Cl1	111.56 (4)
C3—C4—C5	119.03 (17)	N1—Zn1—Cl1	111.56 (4)
C3—C4—H4	120.5	N1^i—Zn1—Cl2	105.48 (4)
C5—C4—H4	120.5	N1—Zn1—Cl2	105.48 (4)
N1—C5—C4	122.85 (17)	Cl1—Zn1—Cl2	120.83 (3)
N1—C5—H5	118.6

Symmetry code: (i) x, −y+3/2, z.

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
C3—H3···O1^ii	0.93	2.49	3.342 (2)	152
C4—H4···O1^iii	0.93	2.66	3.562 (2)	164

Symmetry codes: (ii) −x+2, −y+1, −z; (iii) −x+3/2, −y+1, z−1/2.