Supporting information
Crystallographic Information File (CIF) https://doi.org/10.1107/S1600536805041723/hg6287sup1.cif | |
Structure factor file (CIF format) https://doi.org/10.1107/S1600536805041723/hg6287Isup2.hkl |
CCDC reference: 296575
Compound (I) was prepared according to the literature procedure (Sumby & Steel, 2005). Single crystals suitable for X-ray diffraction were obtained by recrystallizing the polycrystalline powder sample from a ethyl acetate/hexane solution.
All H atoms of pyridyl groups were placed in geometrically calculated positions, with C—H distances of 0.93 Å, and included in the final refinement in the riding-model approximation, with Uiso(H) = 1.2Ueq(C).
Data collection: APEXII (Bruker, 2003); cell refinement: APEXII and SAINT (Bruker, 2001); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: SHELXTL (Bruker, 2001); software used to prepare material for publication: SHELXTL.
Fig. 1. View of the molecular structure of (I), with the atom labeling and with 30% probability displacement ellipsoids (symmetry code: 1/2 − x, y, 1.5 − z). |
C22H16N6 | F(000) = 380 |
Mr = 364.41 | Dx = 1.339 Mg m−3 |
Monoclinic, P2/n | Mo Kα radiation, λ = 0.71073 Å |
Hall symbol: -P 2yac | Cell parameters from 581 reflections |
a = 12.226 (4) Å | θ = 2.8–21.3° |
b = 5.8241 (19) Å | µ = 0.08 mm−1 |
c = 13.617 (4) Å | T = 293 K |
β = 111.265 (6)° | Block, colorless |
V = 903.6 (5) Å3 | 0.32 × 0.25 × 0.18 mm |
Z = 2 |
Bruker APEX-II CCD area-detector diffractometer | 1597 independent reflections |
Radiation source: fine-focus sealed tube | 1121 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.066 |
ϕ and ω scans | θmax = 25.0°, θmin = 1.9° |
Absorption correction: multi-scan (SADABS; Sheldrick, 1996) | h = −12→14 |
Tmin = 0.919, Tmax = 1.000 | k = −6→6 |
4795 measured reflections | l = −16→14 |
Refinement on F2 | Primary atom site location: structure-invariant direct methods |
Least-squares matrix: full | Secondary atom site location: difference Fourier map |
R[F2 > 2σ(F2)] = 0.054 | Hydrogen site location: inferred from neighbouring sites |
wR(F2) = 0.169 | H-atom parameters constrained |
S = 1.16 | w = 1/[σ2(Fo2) + (0.0836P)2] where P = (Fo2 + 2Fc2)/3 |
1597 reflections | (Δ/σ)max < 0.001 |
127 parameters | Δρmax = 0.35 e Å−3 |
0 restraints | Δρmin = −0.28 e Å−3 |
C22H16N6 | V = 903.6 (5) Å3 |
Mr = 364.41 | Z = 2 |
Monoclinic, P2/n | Mo Kα radiation |
a = 12.226 (4) Å | µ = 0.08 mm−1 |
b = 5.8241 (19) Å | T = 293 K |
c = 13.617 (4) Å | 0.32 × 0.25 × 0.18 mm |
β = 111.265 (6)° |
Bruker APEX-II CCD area-detector diffractometer | 1597 independent reflections |
Absorption correction: multi-scan (SADABS; Sheldrick, 1996) | 1121 reflections with I > 2σ(I) |
Tmin = 0.919, Tmax = 1.000 | Rint = 0.066 |
4795 measured reflections |
R[F2 > 2σ(F2)] = 0.054 | 0 restraints |
wR(F2) = 0.169 | H-atom parameters constrained |
S = 1.16 | Δρmax = 0.35 e Å−3 |
1597 reflections | Δρmin = −0.28 e Å−3 |
127 parameters |
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. |
x | y | z | Uiso*/Ueq | ||
N1 | 0.4776 (2) | 0.3476 (4) | 0.61042 (18) | 0.0532 (6) | |
N2 | 0.1982 (2) | 0.5913 (4) | 0.62115 (17) | 0.0551 (7) | |
N3 | 0.30436 (16) | 0.1544 (3) | 0.74614 (14) | 0.0361 (5) | |
C1 | 0.3187 (2) | 0.2434 (4) | 0.66524 (17) | 0.0345 (6) | |
C2 | 0.4305 (2) | 0.1836 (4) | 0.65176 (16) | 0.0362 (6) | |
C3 | 0.4812 (2) | −0.0293 (4) | 0.6799 (2) | 0.0485 (7) | |
H3A | 0.4464 | −0.1394 | 0.7085 | 0.058* | |
C4 | 0.5844 (3) | −0.0761 (5) | 0.6648 (2) | 0.0630 (8) | |
H4A | 0.6203 | −0.2187 | 0.6830 | 0.076* | |
C5 | 0.6336 (2) | 0.0893 (6) | 0.6228 (2) | 0.0611 (8) | |
H5A | 0.7033 | 0.0620 | 0.6120 | 0.073* | |
C6 | 0.5778 (2) | 0.2950 (5) | 0.5971 (2) | 0.0614 (9) | |
H6A | 0.6116 | 0.4067 | 0.5683 | 0.074* | |
C7 | 0.23494 (19) | 0.3991 (4) | 0.58643 (16) | 0.0351 (6) | |
C8 | 0.2009 (2) | 0.3453 (4) | 0.48316 (17) | 0.0423 (6) | |
H8A | 0.2280 | 0.2131 | 0.4612 | 0.051* | |
C9 | 0.1260 (3) | 0.4903 (6) | 0.4127 (2) | 0.0616 (9) | |
H9A | 0.0995 | 0.4533 | 0.3414 | 0.074* | |
C10 | 0.0881 (2) | 0.6887 (5) | 0.4429 (2) | 0.0544 (8) | |
H10A | 0.0380 | 0.7882 | 0.3935 | 0.065* | |
C11 | 0.1259 (2) | 0.7366 (5) | 0.5478 (2) | 0.0528 (7) | |
H11A | 0.1018 | 0.8720 | 0.5699 | 0.063* |
U11 | U22 | U33 | U12 | U13 | U23 | |
N1 | 0.0521 (14) | 0.0523 (14) | 0.0660 (14) | 0.0063 (11) | 0.0343 (12) | 0.0165 (11) |
N2 | 0.0616 (15) | 0.0521 (14) | 0.0494 (13) | 0.0088 (12) | 0.0176 (11) | 0.0008 (11) |
N3 | 0.0379 (11) | 0.0387 (12) | 0.0343 (10) | 0.0003 (8) | 0.0163 (9) | −0.0006 (8) |
C1 | 0.0401 (14) | 0.0329 (13) | 0.0326 (12) | −0.0007 (10) | 0.0155 (10) | −0.0031 (9) |
C2 | 0.0404 (13) | 0.0407 (14) | 0.0292 (11) | 0.0008 (11) | 0.0146 (10) | 0.0003 (10) |
C3 | 0.0489 (16) | 0.0425 (16) | 0.0599 (16) | 0.0066 (12) | 0.0268 (13) | 0.0104 (12) |
C4 | 0.0569 (18) | 0.0571 (18) | 0.082 (2) | 0.0227 (15) | 0.0336 (16) | 0.0154 (16) |
C5 | 0.0474 (17) | 0.079 (2) | 0.0671 (19) | 0.0152 (16) | 0.0328 (15) | 0.0134 (16) |
C6 | 0.0537 (18) | 0.072 (2) | 0.0733 (19) | 0.0062 (15) | 0.0402 (16) | 0.0234 (15) |
C7 | 0.0351 (13) | 0.0385 (13) | 0.0346 (12) | 0.0006 (10) | 0.0163 (10) | 0.0015 (10) |
C8 | 0.0534 (15) | 0.0448 (15) | 0.0318 (12) | 0.0096 (12) | 0.0191 (11) | −0.0041 (11) |
C9 | 0.073 (2) | 0.079 (2) | 0.0312 (14) | −0.0057 (17) | 0.0164 (14) | −0.0039 (14) |
C10 | 0.0502 (16) | 0.0587 (18) | 0.0469 (15) | 0.0087 (14) | 0.0088 (13) | 0.0186 (13) |
C11 | 0.0588 (18) | 0.0441 (16) | 0.0517 (16) | 0.0154 (14) | 0.0154 (14) | 0.0032 (12) |
N1—C6 | 1.337 (3) | C4—C5 | 1.366 (4) |
N1—C2 | 1.340 (3) | C4—H4A | 0.9300 |
C8—C7 | 1.351 (3) | C5—C6 | 1.360 (4) |
C8—C9 | 1.355 (4) | C5—H5A | 0.9300 |
C8—H8A | 0.9300 | C6—H6A | 0.9300 |
N3—C1 | 1.285 (3) | C7—N2 | 1.353 (3) |
N3—N3i | 1.371 (4) | N2—C11 | 1.362 (3) |
C1—C2 | 1.486 (3) | C11—C10 | 1.360 (4) |
C1—C7 | 1.492 (3) | C11—H11A | 0.9300 |
C2—C3 | 1.376 (3) | C10—C9 | 1.363 (4) |
C3—C4 | 1.378 (4) | C10—H10A | 0.9300 |
C3—H3A | 0.9300 | C9—H9A | 0.9300 |
C6—N1—C2 | 116.6 (2) | C6—C5—H5A | 120.9 |
C7—C8—C9 | 117.8 (2) | C4—C5—H5A | 120.9 |
C7—C8—H8A | 121.1 | N1—C6—C5 | 124.4 (3) |
C9—C8—H8A | 121.1 | N1—C6—H6A | 117.8 |
C1—N3—N3i | 120.2 (2) | C5—C6—H6A | 117.8 |
N3—C1—C2 | 115.4 (2) | C8—C7—N2 | 122.7 (2) |
N3—C1—C7 | 126.2 (2) | C8—C7—C1 | 118.7 (2) |
C2—C1—C7 | 118.42 (19) | N2—C7—C1 | 118.7 (2) |
N1—C2—C3 | 122.7 (2) | C7—N2—C11 | 117.8 (2) |
N1—C2—C1 | 116.1 (2) | C10—C11—N2 | 121.7 (3) |
C3—C2—C1 | 121.2 (2) | C10—C11—H11A | 119.1 |
C2—C3—C4 | 118.7 (2) | N2—C11—H11A | 119.1 |
C2—C3—H3A | 120.6 | C11—C10—C9 | 117.9 (2) |
C4—C3—H3A | 120.6 | C11—C10—H10A | 121.1 |
C5—C4—C3 | 119.3 (3) | C9—C10—H10A | 121.1 |
C5—C4—H4A | 120.4 | C8—C9—C10 | 122.1 (2) |
C3—C4—H4A | 120.4 | C8—C9—H9A | 119.0 |
C6—C5—C4 | 118.2 (3) | C10—C9—H9A | 119.0 |
Symmetry code: (i) −x+1/2, y, −z+3/2. |
Experimental details
Crystal data | |
Chemical formula | C22H16N6 |
Mr | 364.41 |
Crystal system, space group | Monoclinic, P2/n |
Temperature (K) | 293 |
a, b, c (Å) | 12.226 (4), 5.8241 (19), 13.617 (4) |
β (°) | 111.265 (6) |
V (Å3) | 903.6 (5) |
Z | 2 |
Radiation type | Mo Kα |
µ (mm−1) | 0.08 |
Crystal size (mm) | 0.32 × 0.25 × 0.18 |
Data collection | |
Diffractometer | Bruker APEX-II CCD area-detector diffractometer |
Absorption correction | Multi-scan (SADABS; Sheldrick, 1996) |
Tmin, Tmax | 0.919, 1.000 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 4795, 1597, 1121 |
Rint | 0.066 |
(sin θ/λ)max (Å−1) | 0.595 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.054, 0.169, 1.16 |
No. of reflections | 1597 |
No. of parameters | 127 |
H-atom treatment | H-atom parameters constrained |
Δρmax, Δρmin (e Å−3) | 0.35, −0.28 |
Computer programs: APEXII (Bruker, 2003), APEXII and SAINT (Bruker, 2001), SAINT, SHELXS97 (Sheldrick, 1997), SHELXL97 (Sheldrick, 1997), SHELXTL (Bruker, 2001), SHELXTL.
Di-2-pyridyl ketone azine, (I), has been long associated with the spectrometric determination of microamounts of metal ions such as CuII (Grases, Estela et al., 1981), AuIII (Grases, Garcia-Sanchez & Valcarcel, 1981), PdII (Garcia Vargas & Valcarcel, 1978), FeII (Valcarcel et al., 1975), NiII and CoII (Valcarcel et al., 1977). A recent investigation of the coordination chemistry of this potential multidentate ligand suggests that (I) forms a discrete tetranuclear complex, (II), with AgNO3, while it decomposes on reaction with Cu(NO3)2 (Sumby & Steel 2005). In the crystal structure of (II), there exist two discrete tetranuclear moieties within the asymmetric unit, each containing two molecules of ligand (I). To develop this project further, we describe here the crystal structure of (I).
The title compound, (I), C22H16N6, crystallizes in monoclinic space group P2/n. The molecules of (I) are disposed about a twofold axis that is perpendicular to the central N—N single bond. Viewed along the twofold axis, all four pyridyl rings in the complete molecule are twisted in the same direction, showing a clockwise or anticlockwise configuration. Similar observations have also been reported in the tetranuclear silver(I) coordination complex (II). On the other hand, the flexible conformation of (I) makes it a potential hexadentate ligand capable of coordination via all its nitrogen donors (Sumby & Steel 2005).
The geometry of the free ligand molecule in (I) differs from that in (II). The dihedral angle between the two pyridyl rings bonding to the same C atom is 73.40 (9)° in (I), while the corresponding values in (II) range from 70.8 to 113.7°, with an average value of 101.0° (Sumby & Steel 2005). For the free molecule of (I), the C—N—N—C torsion angle is −124.4 (2)°, while the four ligand molecules in (II) have the values of −138.0 (5), −149.4 (5), 138.3 (5) and 155.5 (5)°, respectively. The N—N bond length at 1.371 (4) Å for the molecule in (I) is also significantly shorter than those in (II), being 1.399, 1.406, 1.409 and 1.380 Å, respectively. These differences indicate that the ligand molecule (I) takes a more open conformation in its silver(I) coordination complex (II). Further investigation of the crystal packing of (I) indicates that no significant intermolecular interactions, such as hydrogen-bonding and π–π stacking, exist in this structure.