6-Bromo­pyridine-2-carbaldehyde phenyl­hydrazone

The title compound, C₁₂H₁₀BrN₃, is essentially planar (r.m.s. deviation of all non-H atoms = 0.0174 Å), with a dihedral angle of 0.5 (2)° between the two aromatic rings. In the crystal, mol­ecules are linked by weak N—H...N inter­actions, forming a zigzag chain running parallel to [001].

Key indicators

• Single-crystal X-ray study
• T = 295 K
• Mean [sigma](C-C) = 0.004 Å
• R factor = 0.039
• wR factor = 0.110
• Data-to-parameter ratio = 16.1

checkCIF/PLATON results

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Alert level C
PLAT910_ALERT_3_C Missing # of FCF Reflections Below Th(Min) .....          5
PLAT911_ALERT_3_C Missing # FCF Refl Between THmin & STh/L=  0.600          6
PLAT913_ALERT_3_C Missing # of Very Strong Reflections in FCF ....          6

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

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

   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
   0 ALERT type 4 Improvement, methodology, query or suggestion
   2 ALERT type 5 Informative message, check

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S1. Comment

The design of molecular dynamic systems that operate by external stimuli without producing chemical waste is one of the questions of great interest in the nanotechnology field (Hirose, 2010), since these molecular systems are molecules that can exhibit structural (configurational) and chemical (constitutional) changes by the modification of external factors (presence of other molecules or metal ions, heat and/or light). Among the compounds that have attracted interest in this regard are the hydrazones which contain the imine group (-C=N-) (Kay et al., 2007). This group can undergo reversible configurational changes induced by UV light and heat (Chaur et al., 2011). For hydrazones prepared from pyridinecarboxaldehydes and pyridine or phenyl hydrazines the E/Z photoisomerization is favored by an intermolecular hydrogen bond between the hydrazine and the nitrogen of the pyridinecarboxaldehyde group resulting in a metastable state which can be returned to its original state by heating in solution (Chaur et al., 2011; Lehn, 2006; Dugave & Demange, 2003). Besides, these compounds can exhibit dynamic properties since they can undergo coordination with suitable metals and the reversibility of the imine group gives them other features that can be used in the development of molecular machines or in the storage of information (Chaur et al., 2011). The compound reported in this paper is part of a series of compounds that are currently being prepared in our group and that exhibit dynamic properties such as photoisomerization, constitutional changes and metal coordination in order to build supramolecular systems of multiple dynamics. Herein we report the synthesis and crystal structure of 6-bromo-pyridinecarbaldehyde phenylhydrazone (I), Fig 1. In the molecular structure of (I), the bromopyridyl ring is planar (r.m.s. deviation of all non-hydrogen atoms = 0.0020 Å) like the central bridge (C5/C7/N2/N1/C8) (r.m.s. deviation of all non-hydrogen atoms = 0.005 Å) with a dihedral angle of 0.6 (2)° between these two planes. The central bridge forms a dihedral angle of 0.8 (2)° with the benzene ring and the bromopyridyl and benzene rings form a dihedral angle of 0.5 (2)°. The bond lengths agree with the literature values (Allen et al., 1987) and are comparable with the related structures (Yu et al., 2005; Fun et al., 2012). In the crystal packing (Fig. 2), the molecules are linked by weak N—H···N interactions (Table 1). Indeed, in this substructure, atom N1 in the molecule at (x,y,z) links to N3 atom in the molecule at (-x+2,+y-1/2,-z+1/2). The propagation of this interaction forms C(6) (Etter, 1990), continuous one-dimensional zigzag chain running parallel to [001].

Related literature

For bond-length data, see: Allen et al. (1987). For related structures, see: Yu et al. (2005); Fun et al. (2012). For the design of molecular dynamic systems, see: Hirose (2010). For the principles of synthetic molecular structures with dynamic properties, see: Kay et al. (2007). For configurational changes by UV light and heat, see: Chaur et al. (2011); Lehn (2006); Dugave & Demange (2003). For graph-set notation, see: Etter (1990).

S2. Experimental

The hydrazone under study was prepared by the condensation reaction of 6-bromo-2-pyridinecarboxaldehyde with phenylhydrazine in ethanol according to Fig. 3, obtaining a yellow solid with a yield of 81%. ¹H NMR (400 MHz, DMSO-d₆) δppm: 10.83 (s, 1H, NH), 7.92 (d, J= 8.03 Hz, 1H), 7.78 (s, 1H), 7.71 (t, J= 7.78 Hz, 1H), 7.47 (d, J= 7.78 Hz, 1H), 7.26 (m, 2H), 7.13 (d, J= 8.28 Hz, 2H), 6.83 (t, J= 7.28 Hz, 1H). NMR ¹³C (100 MHz, DMSO-d₆) δppm: 156.16, 144.31, 140.77, 139.60, 134.52, 129.27, 126.07, 119.99, 117.80, 112.52. IR (KBr) N(cm^-1): 3228 (N-H), 3038 and 2971 (=C-H), 1558 y 1601 (C=C y C=N). Melting point: 462 (1) K. Elemental analysis: Calculated: C 52.20 %, H 3.65 %, N 15.22 %; found: C 51.98 %, H 3.46 %, N 15.07 %.

S3. Refinement

All H-atoms were positioned geometrically using riding model with [C—H = 0.93 Å with U_iso(H) = 1.2U_eq(C)].

Computing details

Data collection: COLLECT (Nonius, 2000); cell refinement: SCALEPACK (Otwinowski & Minor, 1997); data reduction: DENZO and SCALEPACK (Otwinowski & Minor, 1997; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: ORTEP-3 for Windows (Farrugia, 1997) and Mercury (Macrae et al., 2006); software used to prepare material for publication: WinGX (Farrugia, 1999).

Figures

	Fig. 1. Molecular conformation and atom numbering scheme for (I) with displacement ellipsoids drawn at the 50% probability level. H atoms are shown as spheres of arbitrary radius.
	Fig. 2. Part of the crystal structure of (I), showing the formation of one-dimensional zigzag chain running parallel to (001). Symmetry code: (i) -x+2,+y-1/2,-z+1/2.
	Fig. 3. Synthesis of the 6-bromo-pyridinecarbaldehyde phenylhydrazone

6-Bromopyridine-2-carbaldehyde phenylhydrazone

Crystal data

C12H10BrN3	Dx = 1.593 Mg m^−3
Mr = 276.13	Melting point: 497(1) K
Orthorhombic, Pbca	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ac 2ab	Cell parameters from 9233 reflections
a = 14.6418 (3) Å	θ = 3.6–26.4°
b = 7.8407 (1) Å	µ = 3.54 mm^−1
c = 20.0645 (4) Å	T = 295 K
V = 2303.44 (7) Å^3	Block, black
Z = 8	0.33 × 0.30 × 0.23 mm
F(000) = 1104

Data collection

Nonius KappaCCD diffractometer	2339 independent reflections
Radiation source: fine-focus sealed tube	1903 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.048
CCD rotation images, thick slices scans	θmax = 26.4°, θmin = 3.6°
Absorption correction: multi-scan (SADABS; Sheldrick, 1996)	h = −18→17
Tmin = 0.382, Tmax = 0.544	k = −9→9
28166 measured reflections	l = −24→25

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)] = 0.039	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.110	H-atom parameters constrained
S = 1.03	w = 1/[σ^2(Fo^2) + (0.052P)^2 + 1.6466P] where P = (Fo^2 + 2Fc^2)/3
2339 reflections	(Δ/σ)max < 0.001
145 parameters	Δρmax = 0.44 e Å^−3
0 restraints	Δρmin = −0.72 e Å^−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 > 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
Br1	0.82948 (2)	1.00944 (4)	0.314727 (18)	0.07300 (18)
N1	1.06677 (16)	0.1846 (3)	0.32501 (10)	0.0535 (5)
H1	1.0780	0.2044	0.2837	0.064*
N2	1.01869 (15)	0.2984 (3)	0.36079 (10)	0.0506 (5)
N3	0.91170 (14)	0.6977 (3)	0.33261 (10)	0.0468 (5)
C1	0.86323 (18)	0.8132 (3)	0.36454 (13)	0.0496 (6)
C2	0.8363 (2)	0.8049 (4)	0.43023 (14)	0.0620 (7)
H2	0.8017	0.8907	0.4499	0.074*
C3	0.8635 (2)	0.6620 (4)	0.46526 (14)	0.0674 (8)
H3	0.8471	0.6495	0.5098	0.081*
C4	0.9144 (2)	0.5390 (4)	0.43455 (13)	0.0577 (7)
H4	0.9332	0.4428	0.4579	0.069*
C5	0.93799 (17)	0.5597 (3)	0.36750 (12)	0.0467 (5)
C7	0.99160 (18)	0.4341 (4)	0.33110 (12)	0.0506 (6)
H7	1.0061	0.4522	0.2865	0.061*
C8	1.09823 (17)	0.0360 (3)	0.35418 (12)	0.0460 (5)
C9	1.0819 (2)	−0.0034 (3)	0.42067 (14)	0.0568 (7)
H9	1.0468	0.0692	0.4469	0.068*
C10	1.1179 (2)	−0.1504 (4)	0.44746 (15)	0.0696 (8)
H10	1.1073	−0.1750	0.4921	0.084*
C11	1.1688 (2)	−0.2614 (4)	0.41011 (18)	0.0704 (8)
H11	1.1925	−0.3603	0.4289	0.084*
C12	1.1841 (2)	−0.2232 (4)	0.34413 (17)	0.0670 (8)
H12	1.2184	−0.2976	0.3181	0.080*
C13	1.14946 (19)	−0.0769 (4)	0.31608 (13)	0.0553 (7)
H13	1.1604	−0.0533	0.2714	0.066*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Br1	0.0783 (3)	0.0622 (2)	0.0785 (3)	0.01901 (15)	−0.00590 (15)	0.00948 (14)
N1	0.0623 (14)	0.0528 (13)	0.0454 (11)	0.0095 (11)	0.0048 (9)	−0.0002 (10)
N2	0.0556 (12)	0.0466 (12)	0.0495 (11)	0.0035 (10)	−0.0006 (10)	−0.0039 (10)
N3	0.0477 (11)	0.0483 (12)	0.0444 (10)	−0.0002 (9)	−0.0039 (9)	−0.0015 (9)
C1	0.0487 (13)	0.0479 (14)	0.0521 (14)	0.0009 (11)	−0.0069 (11)	−0.0008 (11)
C2	0.0704 (19)	0.0600 (17)	0.0557 (16)	0.0063 (14)	0.0061 (13)	−0.0107 (13)
C3	0.088 (2)	0.0676 (19)	0.0460 (14)	0.0066 (17)	0.0106 (14)	−0.0021 (14)
C4	0.0731 (18)	0.0524 (14)	0.0475 (14)	0.0013 (14)	0.0007 (13)	0.0024 (12)
C5	0.0491 (13)	0.0472 (13)	0.0440 (13)	−0.0023 (11)	−0.0036 (10)	−0.0007 (11)
C7	0.0548 (15)	0.0530 (14)	0.0439 (12)	0.0004 (12)	−0.0016 (11)	−0.0019 (12)
C8	0.0439 (13)	0.0461 (13)	0.0479 (13)	−0.0012 (10)	−0.0028 (10)	−0.0045 (11)
C9	0.0661 (17)	0.0505 (16)	0.0539 (15)	0.0015 (12)	0.0063 (13)	−0.0007 (11)
C10	0.091 (2)	0.0568 (17)	0.0607 (17)	0.0001 (16)	0.0024 (16)	0.0107 (14)
C11	0.077 (2)	0.0480 (16)	0.086 (2)	0.0088 (14)	−0.0138 (16)	0.0051 (15)
C12	0.0624 (17)	0.0590 (18)	0.080 (2)	0.0144 (14)	−0.0061 (15)	−0.0181 (16)
C13	0.0539 (15)	0.0590 (17)	0.0530 (15)	0.0080 (13)	−0.0020 (12)	−0.0096 (12)

Geometric parameters (Å, º)

Br1—C1	1.900 (3)	C5—C7	1.455 (4)
N1—C8	1.383 (3)	C7—H7	0.9300
N1—H1	0.8600	C8—C13	1.389 (4)
N2—C7	1.282 (3)	C8—C9	1.390 (4)
N2—N1	1.344 (3)	C9—C10	1.376 (4)
N3—C1	1.317 (3)	C9—H9	0.9300
N3—C5	1.345 (3)	C10—C11	1.369 (4)
C1—C2	1.377 (4)	C10—H10	0.9300
C2—C3	1.381 (4)	C11—C12	1.375 (5)
C2—H2	0.9300	C11—H11	0.9300
C3—C4	1.366 (4)	C12—C13	1.375 (4)
C3—H3	0.9300	C12—H12	0.9300
C4—C5	1.398 (4)	C13—H13	0.9300
C4—H4	0.9300
C7—N2—N1	117.7 (2)	N2—C7—H7	120.2
N2—N1—C8	120.5 (2)	C5—C7—H7	120.2
N2—N1—H1	119.7	N1—C8—C13	118.9 (2)
C8—N1—H1	119.7	N1—C8—C9	122.4 (2)
C1—N3—C5	117.0 (2)	C13—C8—C9	118.7 (3)
N3—C1—C2	125.9 (3)	C10—C9—C8	119.7 (3)
N3—C1—Br1	116.18 (19)	C10—C9—H9	120.2
C2—C1—Br1	117.9 (2)	C8—C9—H9	120.2
C1—C2—C3	116.3 (3)	C11—C10—C9	121.8 (3)
C1—C2—H2	121.8	C11—C10—H10	119.1
C3—C2—H2	121.8	C9—C10—H10	119.1
C4—C3—C2	120.0 (3)	C10—C11—C12	118.5 (3)
C4—C3—H3	120.0	C10—C11—H11	120.7
C2—C3—H3	120.0	C12—C11—H11	120.7
C3—C4—C5	119.1 (3)	C13—C12—C11	121.0 (3)
C3—C4—H4	120.4	C13—C12—H12	119.5
C5—C4—H4	120.4	C11—C12—H12	119.5
N3—C5—C4	121.5 (2)	C12—C13—C8	120.4 (3)
N3—C5—C7	115.9 (2)	C12—C13—H13	119.8
C4—C5—C7	122.5 (2)	C8—C13—H13	119.8
N2—C7—C5	119.7 (2)
C7—N2—N1—C8	179.8 (2)	N3—C5—C7—N2	−179.5 (2)
C5—N3—C1—C2	−0.6 (4)	C4—C5—C7—N2	0.2 (4)
C5—N3—C1—Br1	178.54 (17)	N2—N1—C8—C13	−178.5 (2)
N3—C1—C2—C3	0.3 (4)	N2—N1—C8—C9	0.3 (4)
Br1—C1—C2—C3	−178.8 (2)	N1—C8—C9—C10	−177.6 (3)
C1—C2—C3—C4	0.2 (5)	C13—C8—C9—C10	1.2 (4)
C2—C3—C4—C5	−0.3 (5)	C8—C9—C10—C11	−0.9 (5)
C1—N3—C5—C4	0.4 (4)	C9—C10—C11—C12	0.2 (5)
C1—N3—C5—C7	−179.9 (2)	C10—C11—C12—C13	0.2 (5)
C3—C4—C5—N3	0.0 (4)	C11—C12—C13—C8	0.1 (5)
C3—C4—C5—C7	−179.6 (3)	N1—C8—C13—C12	178.0 (3)
N1—N2—C7—C5	179.0 (2)	C9—C8—C13—C12	−0.8 (4)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
N1—H1···N3^i	0.86	2.34	3.180 (3)	166

Symmetry code: (i) −x+2, y−1/2, −z+1/2.