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In the title compound, [Cd(C12H8F2N3)2(C5H5N)2], the Cd atom lies on a crystallographic twofold axis in space group Iba2. The coordination geometry about the CdII ion corresponds to a rhombically distorted octahedron, with two deprotonated 1,3-bis(2-fluoro­phenyl)­triazenide ions, viz. FC6H4NNNC6H4F, acting as bidentate ligands (four-electron donors). Two neutral pyridine (py) mol­ecules complete the coordination sphere in positions cis with respect to one another. The triazenide ligand is not planar (r.m.s. deviation = 0.204 Å), the dihedral angle between the phenyl rings of the terminal 2-fluoro­phenyl substituents being 24.6 (1)°. The triazenide and pyridine Cd—N distances are 2.3757 (18)/2.3800 (19) and 2.3461 (19) Å, respectively. Intermolecular C—H...F interactions generate sheets of mol­ecules in the (010) plane.

Supporting information

cif

Crystallographic Information File (CIF) https://doi.org/10.1107/S0108270104002380/fa1048sup1.cif
Contains datablocks global, I

hkl

Structure factor file (CIF format) https://doi.org/10.1107/S0108270104002380/fa1048Isup2.hkl
Contains datablock I

CCDC reference: 235327

Comment top

The synthesis of the first cadmium(II) 1,3-diaryl-substituted triazenide complex, Cd(ArNNNAr)2 (Ar = p-C6H4NO2) was reported in 1887, whereas the analogous complex with 1,3-diphenyltriazene was prepared in 1963 (Moore & Robinson, 1986, and references therein). More recently, cadmium(II) diaryltriazenide complexes have received attention in connection with the spectrophotometric determination of cadmium based on the chromogenic behavior of triazene derivatives (Hayashibe & Sayama, 1996). To date, only two diaryltriazenide cadmium(II) complexes have been characterized by single-crystal X-ray diffraction, namely [Cd{PhN3(H)C6H4– N3(H)Ph}{PhN3C6H4N3(H)Ph}2], hereafter (II), in which the Cd atom is coordinated by one neutral chelating 1,2-bis(phenyltriazene)benzene ligand and two monodentate 1-phenyltriazenide-2-phenyltriazene benzene anions in a distorted-tetrahedral arrangement, and K[Cd(O2NC6H4NNNC6H4NO2)3], (III), an anionic cadmium complex in which the Cd atom is coordinated in a trigonal-prismatic arrangement by three chelating deprotonated 1,3-bis(4-nitrophenyl)triazenide ions (Hörner et al., 1996, 2003a). In this work, we report the synthesis and structural characterization of the title complex, (I), an axially symmetric mononuclear CdII complex with a symmetrically disubstituted 1,3-diaryltriazenide ion and pyridine (py) as ligands.

Complex (I) has a structure analogous to that of the related CoII complex, [Co(C12H10N3)2(C5H5N)2], hereafter (IV) (Peng et al., 1985). The crystal structure of (I) consists of discrete mononuclear complexes in which the CdII ion has a rhombically distorted-octahedral coordination geometry. Two deprotonated 1,3-bis(2-fluorophenyl)triazenide ions act as (N11)-η1,(N13)-η1 bidentate (four-electron donor) ligands, while two neutral pyridine molecules are coordinated cis to one another (Fig. 1).

In the molecule of (I), which has site symmetry 2, the CdII ion is inserted in a distorted square-planar base formed by atoms N13, N13i, N31 and N31i [r.m.s. deviation 0.286 Å; symmetry code (i): −x, −y + 1, z]. The crystallographic twofold-symmetry axis bisects the N13—Cd—N13i [89.09 (9)°] and N31—Cd—N31i [91.40 (10)°] angles and the N11—Cd—N11i axial angle [141.42 (8)°; symmetry code (i): −x, −y + 1, z]. These values are in good agreement with the angles found in the related compound (IV) [N3—Co—N3i = 90.3 (1)°, N4—Co—N4i = 89.6 (1)° and N1—Co—N1i = 149.6 (1)°, respectively; symmetry code (i): −x, −y + 1, z; i.e. Co is also on a twofold axis; Peng et al., 1985).

As a result of the bidentate coordination mode of the triazenide ligand, the N—N bond lengths are equal to within three standard deviations, with a mean value of 1.307 (4) Å (Table 1). These bond lengths are longer than the typical value for a double bond (1.24 Å; International Tables for Crystallography, 1995, Vol. C), and are similar to the N—N distances observed in the anionic triazenido complex (II) [1.310 (5) and 1.317 (6) Å]. On the other hand, both the N11—C11 [1.398 (3) Å] and N13—C21 [1.405 (3) Å] bonds are shorter than expected for an N—Caryl single bond (1.452 Å for secondary amines, NHR2, with R = Csp2; Orpen et al., 1989). These values, together with the observed N—N bond distances, which imply partial double-bond character, provide evidence for the delocalization of the π electrons on the N—N=N triad towards the terminal 2-fluorophenyl substituents.

The Cd—N11 [2.3757 (18) Å] and Cd—N13 [2.3800 (19) Å] bonds are both longer than the sum of the covalent radii (2.27 Å; Allen et al., 1987; Teatum et al., 1960) and correspond to covalent single bonds. These values are in good agreement with those found in (II) [2.350 (5) and 2.397 (4) Å] and (III) [2.350 (4) and 2.376 (4) Å].

The bidentate coordination mode of the triazenide ligand, together with the acute N11—Cd—N13 angle [53.33 (6)°] give rise to a strained Cd/N11–N13 four-membered ring. The bond angle of the triazenide moiety [109.46 (17)°] deviates only slightly from the angles observed in complexes such trans-[Pd(FC6H4—N=N—NC6H4NO2)2(C5H5N)2] [111.0 (3)°; Hörner et al., 2002] and {Au(O2NC6H4N=N—N—C6H4NO2)[P(C6H5)3]} [110.0 (4)°; Hörner et al., 2003b], in which the triazenide ligand is monodentate.

The terminal 2-fluorophenyl substituents form a dihedral angle of 24.6 (1)°, indicating the lack of planarity of the triazenide ligand.

The crystal structure of (I) reveals molecules linked into chains along the [001] direction via intermolecular C—H···F interactions [C24ii···F1 = 3.351 (3) Å; C24ii—H24ii···F1 = 101.12°; symmetry code: (ii) −x, y, −0.5 + z]; these chains, related by the axial c-glide plane, generate sheets of molecules in the (010) plane (Fig. 2). These values are comparable to that found for C—H···F interactions in the crystal structure of the fluorobenzene C6HF5 [C6···F11 = 3.46 Å; C6—H1···F11 = 120.4°; Thalladi et al., 1998].

The pyridine ring (N31/C32–C36) makes a dihedral angle of 56.4 (6)° with the N11—Cd—N11i moiety [symmetry code: (i) −x, −y + 1, z]. The Cd—N31 bond distance [2.3461 (19) Å] in (I) is longer than the sum of the covalent radii (2.27 Å; Allen et al., 1987; Teatum et al., 1960) and is comparable to the avarage Cd—N bond length found in Cd(py)4Cr2O7 [2.347 (5) Å; Norquist et al., 2001].

Experimental top

Yellow 1,3-bis(2-fluorophenyl)triazene (46.6 mg, 0.2 mmol) was dissolved in methanol (20 ml) and treated with two pellets of KOH, whereupon the solution changed colour to deep red. A solution of cadmium(II) acetate dihydrate (26.7 mg, 0.1 mmol) in methanol (10 ml) was added slowly with continuous stirring while the reaction mixture changed colour to orange–red. The mixture was stirred for 1 h at room temperature, after which pyridine (2 ml) was added and the mixture was stirred for a further 24 h. Orange–red prism-shaped crystals of (I), suitable for X-ray analysis, were obtained by slow evaporation of the solvent at room temperature (yield 42.6 mg, 58%; m.p. 413 K).

Refinement top

The positional parameters of the H atoms were obtained geometrically and the H atoms were treated as riding on their respective C atoms (C–H = 0.93 Å for Csp2 atoms), with a isotropic displacement parameters of 1.2Ueq of the attached Csp2 atom. Friedel pairs were not averaged before refinement. The Flack (1983) parameter was obtained by refinement, including 1829 Friedel pairs. The fluoro F atoms show a large thermal motion, indicated by their elongated displacement ellipsoids (Fig. 1). Split peaks for these atoms were not observed and consequently a disorder model was not used.

Computing details top

Data collection: CAD-4 EXPRESS (Enraf–Nonius, 1994); cell refinement: CAD-4 EXPRESS; data reduction: XCAD4 (Harms & Wocadlo, 1995); program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: ORTEP-3 for Windows (Farrugia, 1997) and DIAMOND (Brandenburg, 1996); software used to prepare material for publication: WinGX (Farrugia, 1999).

Figures top
[Figure 1] Fig. 1. The molecular structure of (I), with 50% probability displacement ellipsoids for non-H atoms. H atoms have been omitted for clarity.
[Figure 2] Fig. 2. The unit cell of (I), in a view slightly inclined from [010]. The intermolecular C—H···F interactions are shown as dashed lines [Symmetry codes: (iii) 0.5 − x, 0.5 + y, z; (iv) 0.5 + x, 0.5 + y, 0.5 + z.]
(I) top
Crystal data top
[Cd(C12H8F2N3)2(C5H5N)2]F(000) = 1480
Mr = 735.03Dx = 1.541 Mg m3
Orthorhombic, Iba2Mo Kα radiation, λ = 0.71073 Å
Hall symbol: I 2 -2cCell parameters from 25 reflections
a = 9.835 (3) Åθ = 7.7–14.0°
b = 19.229 (2) ŵ = 0.75 mm1
c = 16.750 (6) ÅT = 208 K
V = 3167.6 (15) Å3Prism, orange–red
Z = 40.35 × 0.30 × 0.20 mm
Data collection top
Enraf–Nonius CAD-4
diffractometer
3233 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tubeRint = 0.017
Graphite monochromatorθmax = 28.0°, θmin = 3.2°
θ/2θ scansh = 112
Absorption correction: ψ scan
(Spek, 1990)
k = 125
Tmin = 0.779, Tmax = 0.864l = 2222
4462 measured reflections3 standard reflections every 60 min
3800 independent reflections intensity decay: 1%
Refinement top
Refinement on F2 w = 1/[σ2(Fo2) + (0.0256P)2 + 0.7633P]
where P = (Fo2 + 2Fc2)/3
Least-squares matrix: full(Δ/σ)max < 0.001
R[F2 > 2σ(F2)] = 0.021Δρmax = 0.25 e Å3
wR(F2) = 0.053Δρmin = 0.24 e Å3
S = 1.03Extinction correction: SHELXL97, Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4
3800 reflectionsExtinction coefficient: 0.00193 (13)
214 parametersAbsolute structure: Flack (1983), 1829 Friedel pairs
1 restraintAbsolute structure parameter: 0.03 (2)
H-atom parameters constrained
Crystal data top
[Cd(C12H8F2N3)2(C5H5N)2]V = 3167.6 (15) Å3
Mr = 735.03Z = 4
Orthorhombic, Iba2Mo Kα radiation
a = 9.835 (3) ŵ = 0.75 mm1
b = 19.229 (2) ÅT = 208 K
c = 16.750 (6) Å0.35 × 0.30 × 0.20 mm
Data collection top
Enraf–Nonius CAD-4
diffractometer
3233 reflections with I > 2σ(I)
Absorption correction: ψ scan
(Spek, 1990)
Rint = 0.017
Tmin = 0.779, Tmax = 0.8643 standard reflections every 60 min
4462 measured reflections intensity decay: 1%
3800 independent reflections
Refinement top
R[F2 > 2σ(F2)] = 0.021H-atom parameters constrained
wR(F2) = 0.053Δρmax = 0.25 e Å3
S = 1.03Δρmin = 0.24 e Å3
3800 reflectionsAbsolute structure: Flack (1983), 1829 Friedel pairs
214 parametersAbsolute structure parameter: 0.03 (2)
1 restraint
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
Cd0.00000.50000.15184 (2)0.03215 (6)
F10.33216 (14)0.46022 (7)0.10125 (8)0.0443 (3)
F20.31412 (15)0.46036 (9)0.24216 (11)0.0613 (5)
N110.13961 (18)0.40780 (9)0.19869 (10)0.0299 (4)
N120.0601 (2)0.38504 (10)0.25583 (10)0.0307 (4)
N130.0556 (2)0.41796 (10)0.25311 (10)0.0297 (4)
N310.1070 (2)0.43196 (10)0.05402 (11)0.0345 (4)
C110.2649 (2)0.37376 (11)0.19365 (12)0.0301 (4)
C120.3632 (2)0.40201 (11)0.14298 (15)0.0337 (4)
C130.4899 (3)0.37369 (14)0.13303 (12)0.0412 (6)
H130.55230.39440.09880.049*
C140.5241 (3)0.31382 (15)0.17462 (15)0.0464 (7)
H140.60970.29390.16860.056*
C150.4290 (3)0.28393 (13)0.22534 (14)0.0419 (5)
H150.45140.24380.25350.050*
C160.3019 (2)0.31285 (11)0.23453 (13)0.0353 (5)
H160.23940.29170.26840.042*
C210.1468 (2)0.40016 (11)0.31434 (12)0.0315 (4)
C220.2802 (2)0.42252 (13)0.30704 (15)0.0423 (5)
C230.3797 (3)0.40804 (17)0.36286 (19)0.0574 (7)
H230.46850.42330.35520.069*
C240.3453 (3)0.37071 (17)0.42978 (17)0.0581 (8)
H240.41090.36030.46800.070*
C250.2126 (3)0.34857 (15)0.44014 (16)0.0518 (7)
H250.18910.32380.48580.062*
C260.1148 (2)0.36281 (12)0.38349 (12)0.0384 (5)
H260.02620.34740.39140.046*
C320.1659 (3)0.45526 (13)0.01303 (13)0.0399 (5)
H320.15850.50230.02530.048*
C330.2367 (3)0.41286 (14)0.06455 (15)0.0457 (6)
H330.27600.43080.11070.055*
C340.2483 (3)0.34292 (16)0.04616 (15)0.0503 (7)
H340.29650.31310.07950.060*
C350.1875 (3)0.31804 (14)0.02228 (15)0.0479 (6)
H350.19350.27120.03570.057*
C360.1176 (3)0.36399 (12)0.07044 (14)0.0404 (5)
H360.07600.34700.11630.049*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
Cd0.04344 (10)0.02300 (8)0.03001 (9)0.00282 (11)0.0000.000
F10.0439 (8)0.0441 (8)0.0448 (7)0.0073 (7)0.0085 (6)0.0156 (7)
F20.0391 (8)0.0712 (12)0.0736 (11)0.0006 (8)0.0023 (8)0.0242 (10)
N110.0304 (9)0.0288 (9)0.0306 (8)0.0025 (7)0.0020 (7)0.0014 (7)
N120.0344 (9)0.0281 (9)0.0295 (8)0.0040 (8)0.0003 (7)0.0019 (7)
N130.0303 (9)0.0300 (9)0.0288 (9)0.0040 (8)0.0017 (7)0.0001 (7)
N310.0373 (11)0.0298 (10)0.0365 (10)0.0001 (8)0.0008 (8)0.0021 (8)
C110.0334 (11)0.0279 (10)0.0291 (10)0.0004 (9)0.0025 (8)0.0025 (8)
C120.0377 (10)0.0324 (9)0.0311 (12)0.0038 (8)0.0012 (10)0.0022 (10)
C130.0349 (11)0.0501 (12)0.0386 (15)0.0006 (11)0.0045 (9)0.0035 (8)
C140.0408 (15)0.0524 (15)0.0460 (14)0.0143 (11)0.0008 (9)0.0019 (10)
C150.0478 (14)0.0343 (12)0.0437 (13)0.0082 (11)0.0072 (11)0.0038 (10)
C160.0416 (12)0.0288 (10)0.0354 (10)0.0006 (9)0.0000 (10)0.0007 (9)
C210.0349 (10)0.0269 (10)0.0328 (10)0.0087 (9)0.0045 (9)0.0038 (8)
C220.0378 (12)0.0393 (12)0.0499 (13)0.0072 (10)0.0038 (10)0.0003 (11)
C230.0393 (14)0.0616 (19)0.0713 (18)0.0063 (14)0.0172 (13)0.0084 (15)
C240.0579 (17)0.0639 (18)0.0524 (14)0.0246 (15)0.0223 (13)0.0072 (14)
C250.0656 (19)0.0494 (15)0.0404 (13)0.0202 (14)0.0067 (13)0.0050 (11)
C260.0419 (12)0.0366 (11)0.0368 (13)0.0099 (10)0.0009 (9)0.0022 (8)
C320.0410 (13)0.0401 (13)0.0388 (11)0.0066 (11)0.0002 (9)0.0001 (10)
C330.0403 (13)0.0584 (16)0.0386 (11)0.0074 (12)0.0046 (10)0.0024 (12)
C340.0474 (14)0.0614 (17)0.0420 (12)0.0157 (13)0.0025 (11)0.0155 (12)
C350.0620 (16)0.0393 (13)0.0423 (13)0.0128 (12)0.0025 (12)0.0068 (11)
C360.0535 (15)0.0335 (12)0.0343 (10)0.0049 (11)0.0019 (10)0.0014 (9)
Geometric parameters (Å, º) top
Cd—N312.3461 (19)C15—C161.377 (3)
Cd—N31i2.3461 (19)C15—H150.9300
Cd—N11i2.3757 (18)C16—H160.9300
Cd—N112.3757 (18)C21—C221.385 (3)
Cd—N13i2.3800 (19)C21—C261.399 (3)
Cd—N132.3800 (19)C22—C231.382 (4)
F1—C121.354 (2)C23—C241.374 (4)
F1—C24ii3.351 (3)C23—H230.9300
F2—C221.350 (3)C24—C251.384 (4)
F2—C13iii3.136 (3)C24—H240.9300
N11—N121.311 (2)C25—C261.378 (3)
N11—C111.398 (3)C25—H250.9300
N12—N131.303 (3)C26—H260.9300
N13—C211.405 (3)C32—C331.377 (3)
N31—C361.340 (3)C32—H320.9300
N31—C321.341 (3)C33—C341.384 (4)
C11—C121.397 (3)C33—H330.9300
C11—C161.405 (3)C34—C351.379 (4)
C12—C131.370 (3)C34—H340.9300
C13—C141.387 (4)C35—C361.380 (3)
C13—H130.9300C35—H350.9300
C14—C151.388 (4)C36—H360.9300
C14—H140.9300
N31—Cd—N31i91.40 (10)C15—C16—C11121.2 (2)
N31—Cd—N1194.24 (6)C15—C16—H16119.4
N31i—Cd—N11112.80 (6)C11—C16—H16119.4
N11i—Cd—N11141.42 (8)C22—C21—C26116.5 (2)
N31—Cd—N13i166.03 (6)C22—C21—N13117.7 (2)
N31—Cd—N1391.44 (6)C26—C21—N13125.8 (2)
N11i—Cd—N1397.26 (6)F2—C22—C23118.6 (2)
N11—Cd—N1353.33 (6)F2—C22—C21118.2 (2)
N13i—Cd—N1389.09 (9)C23—C22—C21123.3 (3)
C12—F1—C24ii90.53 (13)C24—C23—C22118.8 (3)
C22—F2—C13iii109.57 (14)C24—C23—H23120.6
N12—N11—C11114.43 (17)C22—C23—H23120.6
N12—N11—Cd98.37 (13)C23—C24—C25119.7 (3)
C11—N11—Cd147.03 (13)C23—C24—H24120.1
N13—N12—N11109.46 (17)C25—C24—H24120.1
N12—N13—C21114.45 (18)C26—C25—C24120.7 (3)
N12—N13—Cd98.42 (12)C26—C25—H25119.6
C21—N13—Cd145.93 (16)C24—C25—H25119.6
C36—N31—C32117.7 (2)C25—C26—C21121.0 (2)
C36—N31—Cd115.82 (16)C25—C26—H26119.5
C32—N31—Cd126.33 (16)C21—C26—H26119.5
C12—C11—N11117.70 (18)N31—C32—C33123.1 (2)
C12—C11—C16116.2 (2)N31—C32—H32118.5
N11—C11—C16126.11 (19)C33—C32—H32118.5
F1—C12—C13118.1 (2)C32—C33—C34118.5 (2)
F1—C12—C11118.62 (18)C32—C33—H33120.7
C13—C12—C11123.3 (2)C34—C33—H33120.7
C12—C13—C14119.3 (2)C35—C34—C33119.1 (2)
C12—C13—H13120.4C35—C34—H34120.4
C14—C13—H13120.4C33—C34—H34120.4
C13—C14—C15119.2 (2)C34—C35—C36118.7 (2)
C13—C14—H14120.4C34—C35—H35120.7
C15—C14—H14120.4C36—C35—H35120.7
C16—C15—C14120.9 (2)N31—C36—C35122.9 (2)
C16—C15—H15119.6N31—C36—H36118.5
C14—C15—H15119.6C35—C36—H36118.5
Symmetry codes: (i) x, y+1, z; (ii) x, y, z1/2; (iii) x+1, y, z.

Experimental details

Crystal data
Chemical formula[Cd(C12H8F2N3)2(C5H5N)2]
Mr735.03
Crystal system, space groupOrthorhombic, Iba2
Temperature (K)208
a, b, c (Å)9.835 (3), 19.229 (2), 16.750 (6)
V3)3167.6 (15)
Z4
Radiation typeMo Kα
µ (mm1)0.75
Crystal size (mm)0.35 × 0.30 × 0.20
Data collection
DiffractometerEnraf–Nonius CAD-4
diffractometer
Absorption correctionψ scan
(Spek, 1990)
Tmin, Tmax0.779, 0.864
No. of measured, independent and
observed [I > 2σ(I)] reflections
4462, 3800, 3233
Rint0.017
(sin θ/λ)max1)0.660
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.021, 0.053, 1.03
No. of reflections3800
No. of parameters214
No. of restraints1
H-atom treatmentH-atom parameters constrained
Δρmax, Δρmin (e Å3)0.25, 0.24
Absolute structureFlack (1983), 1829 Friedel pairs
Absolute structure parameter0.03 (2)

Computer programs: CAD-4 EXPRESS (Enraf–Nonius, 1994), CAD-4 EXPRESS, XCAD4 (Harms & Wocadlo, 1995), SHELXS97 (Sheldrick, 1997), SHELXL97 (Sheldrick, 1997), ORTEP-3 for Windows (Farrugia, 1997) and DIAMOND (Brandenburg, 1996), WinGX (Farrugia, 1999).

Selected geometric parameters (Å, º) top
Cd—N312.3461 (19)N11—C111.398 (3)
Cd—N112.3757 (18)N12—N131.303 (3)
Cd—N132.3800 (19)N13—C211.405 (3)
N11—N121.311 (2)
N31—Cd—N31i91.40 (10)N31—Cd—N1391.44 (6)
N31—Cd—N1194.24 (6)N11i—Cd—N1397.26 (6)
N31i—Cd—N11112.80 (6)N11—Cd—N1353.33 (6)
N11i—Cd—N11141.42 (8)N13i—Cd—N1389.09 (9)
N31—Cd—N13i166.03 (6)N13—N12—N11109.46 (17)
Symmetry code: (i) x, y+1, z.
 

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