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A new polymorph of di-2-pyridyl ketone 4-nitro­phenyl­hydrazone [alternative name: N-(di­pyridin-2-ylmethyl­ene)-N′-(4-nitro­phen­yl)hydrazine], C17H13N5O2, isolated from the filtrate of a sonicated acetonitrile solution of dpknph and CdCl2, was found to crystallize in the monoclinic space group P21/c, in contrast to the known form which crystallizes in P21/n. The non-coplanar mol­ecules pack in parallel stacks without any inter­molecular hydrogen-bonding inter­actions. This packing pattern contrasts with the inter­locked inter­digitated packing seen in the previously known polymorph.

Supporting information

cif

Crystallographic Information File (CIF) https://doi.org/10.1107/S0108270105027320/bm1616sup1.cif
Contains datablocks global, I

hkl

Structure factor file (CIF format) https://doi.org/10.1107/S0108270105027320/bm1616Isup2.hkl
Contains datablock I

CCDC reference: 288631

Comment top

In recent reports (Bakir & Abdur-Rashid, 1999; Bakir, 2001; Bakir & Brown, 2002; Bakir & Gyles, 2002; Bakir et al., 2000, 2003, 2005) we described the synthesis, structures and reactions of di-2-pyridyl ketone 4-nitrophenylhydrazone (dpknph) and its metal complexes, which revealed a high sensitivity of dpknph and its metal compounds to slight variations in their surroundings. Optosensing measurements on dpknph show a reversible interconversion between two charge transfer electronic states, and substrates with concentrations as low as 1.00x10−7 M can be detected and measured using dpknph in DMSO (dimethyl sulfoxide). Thermo-optical measurements on dpknph in DMSO confirmed the reversible interconversion between high- and low-energy electronic states of dpknph, and allowed for the calculations of their thermodynamic activation parameters. Thus changes in enthalpy (ΔHϕ) of 249.05 ± 1.25 kJ mol−1, entropy (ΔSϕ) of + 0.16 ± 0.04 kJ mol−1 and free energy (ΔGϕ) of −96.30 ± 2.45 kJ mol−1 were determined at 295 K.

Although several attempts were made to explore the polymorphic behavior of di-2-pyridyl ketone (dpk) hydrazones and their metal compounds, prior to this report we were not able to isolate any polymorphic form of dpk hydrazone. In the course of exploring the optosensing behavior and reactions of dpknph with group 12 metal halides in acetonitrile, a new polymorphic form of dpknph was isolated when the filtrate of a sonicated acetonitrile solution of dpknph and CdCl2 was allowed to stand at room temperature for several days. We have designated this polymorph β-dpknph.

##AUTHOR: The non-classical C14—H14···N2 hydrogen bond is a bit improbable, given the rather acute angle of 111.2 degrees. I have removed it from the discussion but left it in the hydrogen bond geometry loop.

A view of the molecular structure of β-dpknph is shown in Fig. 1. With the exception of slight variations of less than 4° in bond angles about the bridging carbon atom (C01) of the dpk moiety, there are no significant variations in bond distances and valence angles between the molecules in the α- and β-dpknph forms. However, pronounced differences between α- and β-dpknph are apparent in the conformation of the pyridine rings about the bridging C atom of the dpk moiety (see Table 1). In the case of β-dpknph, atom N1 is in close proximity to atom N4, and atom N2 is in close proximity proximity to atom C14 (see Fig. 1). This orientation is the result of a classical intramolecular N—H···N hydrogen bond between atoms N1 and N4. The bond distances and angle of the hydrogen bonds (see Table 2) are similar to those in a variety of compounds containing such bonds; for example, in di-2-pyridyl ketone p-aminobenzoylhydrazone hydrate (dpkbz·H2O; Bakir & Green, 2002), hydrogen-bonding parameters D—H, H···A, D···A and D—H···A of 0.86, 2.01, 2.656 (2) Å and 131° were observed for the classical N—H···N hydrogen bond and values of 0.93, 2.52, 3.325 (2) Å and 142° were observed for a non-classical C—H···O hydrogen bond. In the case of α-dpknph, the 4-nitrophenylhydrazone moiety and the N1 pyridine ring are coplanar and orthogonal to the N2 pyridine ring, and hence do not allow for the formation of any suitable intramolecular hydrogen bonding.

In β-dpknph, torsion angles of −12.55 (19) and 131.90 (12)° were observed for N3—C01—C15—N1 and N3—C01—C25—N2, respectively, while for α-dpknph the analogous angles are 94.4 (3) and 176.1 (2)°. The pyridine rings in α-dpknph are nearly perpendicular [dihedral angle ??.?? (s.u.)°], while in the case of β-dpknph the dihedral angle between the pyridine rings is 56.36 (12)°.

The packing of β-dpknph molecules along the c axis, shown in Fig. 2, reveals parallel stacks of β-dpknph molecules aong the a axis and the absence of intermolecular interactions such as hydrogen-bonding between stacks. Alternate molecules in the stacks are related by inversion. This packing pattern contrasts with the interlocked, interdigitated packing behavior of α-dpknph (see Fig. 3), which also displayed an extensive network of non-covalent intermolecular interactions, namely N1···N4, N2···C14 and C11···O2 (see Fig. 4).

In conclusion, a second polymorphic form of dpknph has been isolated, and the solid-state structural analysis reveals significant conformational differences between α- and β-dpknph as manifested by the orientation of the pyridine rings around the bridging C atom of dpk and the differing types of intermolecular hydrogen-bonding interactions. The rich physicochemical properties of hydrazones and their metal complexes has led to a number of possible applications in, for example, nonlinear optics and molecular sensing. We are therefore actively exploring the structures of a variety of di-2-pyridyl ketone hydrazones.

Experimental top

When an equimolar mixture of dpknph and CdCl2 dissolved in acetonitrile was subjected to ultrasonic radiation for an hour, and the filtrate of the reaction mixture was allowed to stand at room temperature for several days, an orange crystal originally thought to be Cd(dpknph)Cl2 was isolated.

Refinement top

##AUTHOR: Please check wording below: All H atoms of β-dpknph were assigned by assuming idealized geometry with C—H distances of 0.93 Å and with Uiso(H) valus of 1.2Ueq(carrier). The N-bound atom H4 was refined freely.

Computing details top

Data collection: SMART (Bruker, 2001); cell refinement: SAINT (Bruker, 2001); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 1990); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: SHELXTL (Bruker, 1997) and PLATON (Spek, 2003); software used to prepare material for publication: SHELXTL.

Figures top
[Figure 1] Fig. 1. The molecular structure of (I), with displacement ellipsoids drawn at the 30% probability level. The intramolecular hydrogen bond is shown as a dashed line.
[Figure 2] Fig. 2. The packing in β-dpknph.
[Figure 3] Fig. 3. The packing in α-dpknph.
[Figure 4] Fig. 4. The intermolecular hydrogen bonds in α-dpknph.
β-di-2-pyridyl ketone 4-nitrophenylhydrazone top
Crystal data top
C17H13N5O2F(000) = 664
Mr = 319.32Dx = 1.384 Mg m3
Monoclinic, P21/cMo Kα radiation, λ = 0.71073 Å
a = 7.9415 (9) ÅCell parameters from 2735 reflections
b = 22.123 (3) Åθ = 2.5–23.0°
c = 8.9747 (10) ŵ = 0.10 mm1
β = 103.606 (2)°T = 296 K
V = 1532.5 (3) Å3Plate, orange
Z = 40.32 × 0.22 × 0.12 mm
Data collection top
Bruker SMART CCD area detector
diffractometer
1961 reflections with I > 2σ(I)
Radiation source: sealed tubeRint = 0.053
Graphite monochromatorθmax = 28.2°, θmin = 1.8°
ω scansh = 1010
13621 measured reflectionsk = 2828
3630 independent reflectionsl = 1111
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)] = 0.041Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.095H atoms treated by a mixture of independent and constrained refinement
S = 0.87 w = 1/[σ2(Fo2) + (0.0426P)2]
where P = (Fo2 + 2Fc2)/3
3630 reflections(Δ/σ)max < 0.001
221 parametersΔρmax = 0.13 e Å3
0 restraintsΔρmin = 0.12 e Å3
Crystal data top
C17H13N5O2V = 1532.5 (3) Å3
Mr = 319.32Z = 4
Monoclinic, P21/cMo Kα radiation
a = 7.9415 (9) ŵ = 0.10 mm1
b = 22.123 (3) ÅT = 296 K
c = 8.9747 (10) Å0.32 × 0.22 × 0.12 mm
β = 103.606 (2)°
Data collection top
Bruker SMART CCD area detector
diffractometer
1961 reflections with I > 2σ(I)
13621 measured reflectionsRint = 0.053
3630 independent reflections
Refinement top
R[F2 > 2σ(F2)] = 0.0410 restraints
wR(F2) = 0.095H atoms treated by a mixture of independent and constrained refinement
S = 0.87Δρmax = 0.13 e Å3
3630 reflectionsΔρmin = 0.12 e Å3
221 parameters
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.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top
xyzUiso*/Ueq
O10.06012 (15)0.32563 (6)0.53397 (14)0.0962 (4)
O20.03396 (19)0.25831 (7)0.36814 (16)0.1159 (5)
N10.33555 (14)0.51718 (6)0.17277 (13)0.0602 (3)
N20.59254 (15)0.64328 (6)0.14887 (14)0.0697 (4)
N30.27824 (14)0.53816 (6)0.13165 (13)0.0565 (3)
N40.21419 (14)0.48522 (6)0.06532 (15)0.0585 (3)
H40.2411 (17)0.4755 (6)0.0302 (17)0.071 (5)*
N50.02572 (16)0.31079 (8)0.41359 (17)0.0749 (4)
C110.34965 (18)0.51277 (8)0.31752 (18)0.0684 (4)
H110.32660.47550.36610.082*
C120.39607 (19)0.55979 (9)0.39921 (18)0.0732 (5)
H120.40340.55460.50030.088*
C130.43128 (19)0.61450 (9)0.32759 (19)0.0752 (5)
H130.46340.64730.37940.090*
C140.41865 (18)0.62038 (8)0.17860 (18)0.0667 (4)
H140.44170.65740.12870.080*
C150.37129 (16)0.57091 (7)0.10231 (16)0.0548 (4)
C010.35261 (16)0.57601 (6)0.05695 (16)0.0537 (4)
C210.6654 (2)0.68859 (8)0.2393 (2)0.0798 (5)
H210.77900.69890.23950.096*
C220.5841 (2)0.72098 (8)0.33193 (19)0.0787 (5)
H220.64120.75220.39300.094*
C230.4167 (2)0.70631 (8)0.33234 (19)0.0750 (5)
H230.35730.72760.39330.090*
C240.33807 (19)0.65968 (7)0.24146 (18)0.0651 (4)
H240.22450.64890.24030.078*
C250.42854 (17)0.62882 (6)0.15181 (15)0.0558 (4)
C310.14816 (15)0.44382 (7)0.15104 (16)0.0519 (4)
C320.11948 (17)0.45811 (7)0.29379 (16)0.0608 (4)
H320.14000.49710.33220.073*
C330.06078 (17)0.41454 (8)0.37806 (16)0.0634 (4)
H330.04200.42390.47390.076*
C340.02985 (16)0.35701 (7)0.32037 (17)0.0578 (4)
C350.05154 (17)0.34245 (7)0.17694 (17)0.0630 (4)
H350.02700.30370.13790.076*
C360.10985 (17)0.38589 (7)0.09253 (16)0.0609 (4)
H360.12400.37660.00480.073*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
O10.0899 (8)0.1326 (11)0.0772 (9)0.0037 (7)0.0422 (7)0.0310 (8)
O20.1486 (13)0.0925 (11)0.1123 (11)0.0404 (9)0.0424 (9)0.0082 (9)
N10.0533 (7)0.0753 (9)0.0532 (8)0.0093 (6)0.0151 (6)0.0099 (7)
N20.0538 (7)0.0886 (10)0.0692 (9)0.0019 (7)0.0195 (6)0.0004 (7)
N30.0466 (6)0.0653 (8)0.0589 (8)0.0084 (6)0.0149 (6)0.0098 (7)
N40.0536 (7)0.0722 (9)0.0528 (8)0.0023 (6)0.0187 (6)0.0087 (7)
N50.0565 (8)0.0970 (12)0.0715 (10)0.0063 (8)0.0156 (7)0.0210 (9)
C110.0638 (10)0.0872 (12)0.0552 (10)0.0111 (8)0.0162 (8)0.0052 (9)
C120.0655 (10)0.1068 (15)0.0505 (10)0.0151 (10)0.0201 (8)0.0171 (10)
C130.0677 (10)0.0948 (13)0.0651 (11)0.0045 (9)0.0194 (8)0.0273 (10)
C140.0632 (9)0.0772 (11)0.0603 (10)0.0054 (8)0.0159 (8)0.0168 (8)
C150.0403 (7)0.0720 (10)0.0527 (9)0.0121 (7)0.0118 (6)0.0161 (8)
C010.0424 (7)0.0652 (9)0.0559 (9)0.0114 (7)0.0160 (6)0.0159 (8)
C250.0526 (8)0.0635 (9)0.0537 (9)0.0074 (7)0.0171 (7)0.0156 (7)
C240.0618 (9)0.0661 (10)0.0736 (11)0.0059 (8)0.0286 (8)0.0096 (9)
C230.0872 (12)0.0714 (11)0.0750 (12)0.0065 (10)0.0366 (9)0.0042 (9)
C220.0835 (12)0.0811 (12)0.0713 (11)0.0065 (10)0.0183 (9)0.0027 (9)
C210.0608 (10)0.1012 (14)0.0770 (12)0.0100 (9)0.0158 (9)0.0016 (11)
C310.0373 (7)0.0685 (10)0.0509 (9)0.0055 (7)0.0122 (6)0.0112 (7)
C320.0578 (9)0.0700 (10)0.0585 (10)0.0006 (7)0.0212 (7)0.0004 (8)
C330.0558 (8)0.0880 (12)0.0500 (9)0.0020 (8)0.0200 (7)0.0048 (9)
C340.0416 (7)0.0744 (11)0.0582 (9)0.0019 (7)0.0130 (7)0.0131 (8)
C350.0540 (9)0.0711 (10)0.0656 (10)0.0043 (7)0.0176 (7)0.0004 (8)
C360.0549 (8)0.0786 (11)0.0514 (9)0.0008 (8)0.0172 (7)0.0015 (8)
Geometric parameters (Å, º) top
N3—N41.3574 (16)C24—H240.9300
N4—H40.956 (15)C23—C221.370 (2)
N5—O11.2200 (17)C23—H230.9300
N5—O21.2273 (17)C22—C211.369 (2)
C11—N11.3334 (17)C22—H220.9300
C11—C121.372 (2)C21—N21.3332 (19)
C11—H110.9300C21—H210.9300
C12—C131.368 (2)C31—N41.3767 (16)
C12—H120.9300C31—C321.3894 (18)
C13—C141.370 (2)C31—C361.3913 (19)
C13—H130.9300C32—C331.373 (2)
C14—C151.3890 (19)C32—H320.9300
C14—H140.9300C33—C341.374 (2)
C15—N11.3450 (17)C33—H330.9300
C15—C011.4757 (19)C34—C351.3766 (19)
C01—N31.2983 (16)C34—N51.4539 (19)
C01—C251.4873 (19)C35—C361.3700 (19)
C25—N21.3474 (16)C35—H350.9300
C25—C241.3790 (18)C36—H360.9300
C24—C231.371 (2)
N1—C11—C12124.04 (16)N2—C21—C22124.33 (15)
N1—C11—H11118.0N2—C21—H21117.8
C12—C11—H11118.0C22—C21—H21117.8
C13—C12—C11118.08 (16)N4—C31—C32122.05 (14)
C13—C12—H12121.0N4—C31—C36118.69 (13)
C11—C12—H12121.0C32—C31—C36119.26 (13)
C12—C13—C14119.25 (16)C33—C32—C31119.93 (15)
C12—C13—H13120.4C33—C32—H32120.0
C14—C13—H13120.4C31—C32—H32120.0
C13—C14—C15119.78 (16)C32—C33—C34119.77 (14)
C13—C14—H14120.1C32—C33—H33120.1
C15—C14—H14120.1C34—C33—H33120.1
N1—C15—C14121.08 (14)C33—C34—C35121.23 (14)
N1—C15—C01117.70 (13)C33—C34—N5119.08 (15)
C14—C15—C01121.19 (15)C35—C34—N5119.68 (15)
N3—C01—C15127.77 (14)C36—C35—C34119.06 (15)
N3—C01—C25112.55 (13)C36—C35—H35120.5
C15—C01—C25119.66 (12)C34—C35—H35120.5
N2—C25—C24122.18 (14)C35—C36—C31120.66 (14)
N2—C25—C01116.03 (12)C35—C36—H36119.7
C24—C25—C01121.75 (13)C31—C36—H36119.7
C23—C24—C25119.53 (15)C11—N1—C15117.77 (13)
C23—C24—H24120.2C21—N2—C25116.74 (13)
C25—C24—H24120.2C01—N3—N4119.94 (12)
C22—C23—C24118.89 (15)N3—N4—C31118.79 (13)
C22—C23—H23120.6N3—N4—H4116.6 (8)
C24—C23—H23120.6C31—N4—H4123.2 (8)
C21—C22—C23118.33 (16)O1—N5—O2122.91 (15)
C21—C22—H22120.8O1—N5—C34118.81 (16)
C23—C22—H22120.8O2—N5—C34118.28 (15)
N1—C11—C12—C130.5 (2)C32—C33—C34—N5177.59 (12)
C11—C12—C13—C140.2 (2)C33—C34—C35—C361.9 (2)
C12—C13—C14—C150.3 (2)N5—C34—C35—C36177.71 (12)
C13—C14—C15—N10.7 (2)C34—C35—C36—C310.5 (2)
C13—C14—C15—C01178.60 (12)N4—C31—C36—C35176.95 (12)
N1—C15—C01—N312.55 (19)C32—C31—C36—C352.81 (19)
C14—C15—C01—N3165.38 (13)C12—C11—N1—C150.9 (2)
N1—C15—C01—C25165.75 (11)C14—C15—N1—C111.00 (18)
C14—C15—C01—C2516.32 (18)C01—C15—N1—C11178.93 (11)
N3—C01—C25—N2131.90 (12)C22—C21—N2—C250.7 (2)
C15—C01—C25—N246.65 (16)C24—C25—N2—C211.1 (2)
N3—C01—C25—C2445.90 (17)C01—C25—N2—C21176.70 (13)
C15—C01—C25—C24135.55 (13)C15—C01—N3—N43.48 (19)
N2—C25—C24—C230.7 (2)C25—C01—N3—N4174.92 (10)
C01—C25—C24—C23176.97 (13)C01—N3—N4—C31174.98 (11)
C25—C24—C23—C220.2 (2)C32—C31—N4—N310.51 (18)
C24—C23—C22—C210.5 (2)C36—C31—N4—N3169.25 (11)
C23—C22—C21—N20.1 (3)C33—C34—N5—O17.25 (19)
N4—C31—C32—C33177.07 (12)C35—C34—N5—O1173.14 (13)
C36—C31—C32—C332.68 (19)C33—C34—N5—O2171.92 (14)
C31—C32—C33—C340.3 (2)C35—C34—N5—O27.7 (2)
C32—C33—C34—C352.0 (2)
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
N4—H4···N10.956 (15)1.871 (15)2.6389 (16)135.5 (12)
C14—H14···N20.932.522.982 (2)111

Experimental details

Crystal data
Chemical formulaC17H13N5O2
Mr319.32
Crystal system, space groupMonoclinic, P21/c
Temperature (K)296
a, b, c (Å)7.9415 (9), 22.123 (3), 8.9747 (10)
β (°) 103.606 (2)
V3)1532.5 (3)
Z4
Radiation typeMo Kα
µ (mm1)0.10
Crystal size (mm)0.32 × 0.22 × 0.12
Data collection
DiffractometerBruker SMART CCD area detector
diffractometer
Absorption correction
No. of measured, independent and
observed [I > 2σ(I)] reflections
13621, 3630, 1961
Rint0.053
(sin θ/λ)max1)0.665
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.041, 0.095, 0.87
No. of reflections3630
No. of parameters221
H-atom treatmentH atoms treated by a mixture of independent and constrained refinement
Δρmax, Δρmin (e Å3)0.13, 0.12

Computer programs: SMART (Bruker, 2001), SAINT (Bruker, 2001), SAINT, SHELXS97 (Sheldrick, 1990), SHELXL97 (Sheldrick, 1997), SHELXTL (Bruker, 1997) and PLATON (Spek, 2003), SHELXTL.

Selected geometric parameters (Å, º) top
N3—N41.3574 (16)C01—N31.2983 (16)
N5—O11.2200 (17)C01—C251.4873 (19)
C11—N11.3334 (17)C25—N21.3474 (16)
C11—C121.372 (2)C31—N41.3767 (16)
C15—N11.3450 (17)C34—N51.4539 (19)
C15—C011.4757 (19)
C14—C15—C01121.19 (15)N4—C31—C32122.05 (14)
N3—C01—C15127.77 (14)C01—N3—N4119.94 (12)
N3—C01—C25112.55 (13)N3—N4—C31118.79 (13)
C15—C01—C25119.66 (12)O1—N5—O2122.91 (15)
N2—C25—C01116.03 (12)
N1—C15—C01—N312.55 (19)C15—C01—C25—N246.65 (16)
C14—C15—C01—N3165.38 (13)N3—C01—C25—C2445.90 (17)
N1—C15—C01—C25165.75 (11)C15—C01—N3—N43.48 (19)
C14—C15—C01—C2516.32 (18)C25—C01—N3—N4174.92 (10)
N3—C01—C25—N2131.90 (12)C01—N3—N4—C31174.98 (11)
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
N4—H4···N10.956 (15)1.871 (15)2.6389 (16)135.5 (12)
C14—H14···N20.932.522.982 (2)111
 

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