Crystal structure of [3-amino-2-(phenyl­diazenyl)­pyridine]chlorido­(η6-p-cymene)­ruthenium(II) chloride

Kanidtha Hansongnern; Supojjanee Sansook; Thassani Romin; Arunpatcha Nimthong Roldan; Chaveng Pakawatchai

doi:10.1107/S2056989015017466

. 2015 Sep 26;71(Pt 10):m185–m186. doi: 10.1107/S2056989015017466

Crystal structure of [3-amino-2-(phenyldiazenyl)pyridine]chlorido(η⁶-p-cymene)ruthenium(II) chloride

Kanidtha Hansongnern ^a,^*, Supojjanee Sansook ^a, Thassani Romin ^a, Arunpatcha Nimthong Roldan ^b, Chaveng Pakawatchai ^a

PMCID: PMC4647410 PMID: 26594428

Abstract

The title compound, [RuCl(C₁₀H₁₄)(C₁₁H₁₀N₄)]Cl is an Ru^II complex in which an η⁶-p-cymene ligand, two N atoms of 3-amino-2-(phenylazo)pyridine and one Cl ion form a piano-stool coordination environment around the metal ion. In the crystal structure, N—H⋯Cl hydrogen bonds play an important role in the formation of the supramolecular zigzag chain along the a-axis direction. Disorder is observed for the isopropyl group with site-occupancy factors refined to 0.78 (5) and 0.22 (5).

Keywords: crystal structure, 3-amino-2-(phenylazo)pyridine, ruthenium complex, N—H⋯Cl hydrogen bonds

Related literature

For anticancer activity of organometallic ruthenium complexes, see: Almodares et al. (2014 ▸); Stepanenko et al. (2011 ▸). For the use of a similar azopyridine ligand to stabilize ruthenium complexes, see: Velders et al. (2000 ▸). For related η⁶-p-cymene ruthenium complexes, see: Singh et al. (2002 ▸), Kumar et al. (2008 ▸). For the crystal structure of an η⁶-p-cymene ruthenium complex with an azopyridine ligand, see: Dougan et al. (2006 ▸). graphic file with name e-71-0m185-scheme1.jpg

Experimental

Crystal data

[RuCl(C₁₀H₁₄)(C₁₁H₁₀N₄)]Cl
M _r = 504.41
Orthorhombic,
a = 8.9642 (8) Å
b = 17.6283 (16) Å
c = 26.976 (3) Å
V = 4262.8 (7) Å³
Z = 8
Mo Kα radiation
μ = 1.00 mm⁻¹
T = 293 K
0.44 × 0.10 × 0.07 mm

Data collection

Bruker SMART APEX CCD Diffractometer
Absorption correction: multi-scan (SADABS; Bruker, 2003 ▸) T _min = 0.693, T _max = 1.000
40186 measured reflections
5127 independent reflections
4242 reflections with I > 2σ(I)
R _int = 0.069

Refinement

R[F ² > 2σ(F ²)] = 0.074
wR(F ²) = 0.136
S = 1.12
5127 reflections
265 parameters
15 restraints
H-atom parameters constrained
Δρ_max = 0.71 e Å⁻³
Δρ_min = −1.61 e Å⁻³

Data collection: SMART (Bruker, 1998 ▸); cell refinement: SAINT (Bruker, 2003 ▸); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▸); program(s) used to refine structure: SHELXL2012 (Sheldrick, 2015 ▸) and SHELXLE (Hübschle et al., 2011 ▸); molecular graphics: Mercury (Macrae et al., 2008 ▸); software used to prepare material for publication: SHELXL97 (Sheldrick, 2008 ▸) and publCIF (Westrip, 2010 ▸).

Supplementary Material

Crystal structure: contains datablock(s) I. DOI: 10.1107/S2056989015017466/zq2235sup1.cif

e-71-0m185-sup1.cif^{(1.2MB, cif)}

Structure factors: contains datablock(s) I. DOI: 10.1107/S2056989015017466/zq2235Isup2.hkl

e-71-0m185-Isup2.hkl^{(408.4KB, hkl)}

Click here for additional data file.^{(1.7MB, tif)}

. DOI: 10.1107/S2056989015017466/zq2235fig1.tif

The molecular structure of the title compound showing the atom-labelling scheme. Displacement ellipsoids are drawn at the 30% probability level.

Click here for additional data file.^{(1.5MB, tif)}

a . DOI: 10.1107/S2056989015017466/zq2235fig2.tif

Crystal packing of the title compound showing the N—H⋯Cl hydrogen bonds along the a axis.

CCDC reference: 1425731

Additional supporting information: crystallographic information; 3D view; checkCIF report

Table 1. Hydrogen-bond geometry (, ).

DHA	DH	HA	D A	DHA
N4H4ACl2	0.86	2.34	3.200(5)	176
N4H4BCl2ⁱ	0.86	2.37	3.152(5)	151

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Symmetry code: (i) Inline graphic .

Acknowledgments

Financial support from the Center of Excellence for Innovation of Chemistry (PERCH–CIC), Office of the Higher Education Commission, Ministry of Education, Department of Chemistry, and Graduate School, Prince of Songkla University are gratefully acknowledged.

supplementary crystallographic information

S0.1. Synthesis and crystallization

3-amino-2-(phenylazo)pyridine (3aazpy) was prepared by condensation of 2,3-diamino-pyridine (14 mg, 2 mmol) with nitrosobenzene (217 mg, 2.1 mmol) in a mixture of 30 M NaOH (3 mL) and 35 mL of benzene solution. The reaction mixture was stirred and heated under reflux for 14 h. The product was extracted many times with benzene to obtain the brown solution. Then the volume was reduced to 3 mL. The residue was purified by column chromatography. The red-orange band was collected and evaporated to dryness (yield : 37%).

The title compound was obtained by the following procedure: [(η⁶-p-cym)RuCl₂]₂ (0.05 mmol) was added to a THF solution of 3aazpy (0.1 mmol); the solution color change from red to purple. The solution was stirred at ambient temperature for 2 h. The precipitate was collected by filtration, washed with a small amount of THF. Monocrystals were obtained by diffusion of ether into a dichloromethane solution of the complex (yield: 82%).

S0.2. Refinement

H atoms bonded to C and N atoms were included in calculated positions and were refined with a riding model using distances of 0.93 Å (aryl H), and U_iso(H) = 1.2U_eq(C); 0.98 Å (CH) and U_iso(H) = 1.5U_eq(C); 0.96 Å (CH₃) and U_iso(H) = 1.5U_eq(C); 0.86 Å (NH₂), and U_iso(H) = 1.2U_eq(N). A disorder is observed for the isopropyl group with site-occupancy factors refined to 0.78 (5) and 0.22 (5).

S1. Results and discussion

Organometallic ruthenium complexes have gained much interest due to promising anticancer activity (Almodares et al., 2014; Stepanenko et al., 2011). These arene complexes consist of a chelating ligand and one chloride ion. In this work, a new ruthenium(II) complex of this type is reported.

The title complex exists as a half sandwich complex with the neutral arene ring bonded to the ruthenium center along with two N atoms from 3-amino-2-(phenylazo)pyridine (3aazpy) and one chloride ion (Fig. 1). The 3aazpy ligand contains the –N=N—C=N linkage which is similar to 2-(phenylazo)pyridine (azpy). Azo ligands of this type can stabilize metals in their lower oxidation states (Velders et al., 2000). The ruthenium atom is π-bonded to the p-cymene ligand with an average Ru—C bond length of 2.215 (6) Å (range 2.185 (6) - 2.243 (5) Å) similar to those observed in related η⁶-p-cymene ruthenium complexes (Singh et al., 2002, Kumar et al., 2008). The p-cymene ring is almost planar and the C—C bond lengths within the ring are in the range 1.376 – 1.435 Å. The ruthenium center is also coordinated to N1 (azo moiety, 2.078 (4) Å) and to N3 (pyridine, 2.077 (4) Å) of 3aazpy. These Ru—N bond lengths are longer than those in [(η⁶-p-cymene)Ru(azpy)Cl](PF₆) (Dougan et al., 2006). It indicates that azpy is a better ligand to stabilize the ruthenium(II) center than 3aazpy. Meanwhile, the bite angle of 75.6 (2)° of the chelate ligand and the Ru—Cl bond distance of 2.3938 (15) Å are comparable to those in [(η⁶-p-cym)Ru(azpy)Cl](PF₆). In the crystal structure, chloride ions are linked with the complex molecule through N4—H4A···Cl2ⁱ and N4—H4B···Cl2 hydrogen bonds leading to the formation of a 1-D zigzag chain along the a-axis (see Table 1 and Fig. 2). A disorder is observed for the isopropyl group with site-occupancy factors refined to 0.78 (5) and 0.22 (5).