(E)-6,6′-(Diazene-1,2-di­yl)bis­(1,10-phenanthrolin-5-ol) tri­chloro­methane disolvate: a superconjugated ligand

Ahmed, M.; Devereux, M.; McKee, V.; McCann, M.; Rooney, A.D.

doi:10.1107/S205698901900954X

research communications

CRYSTALLOGRAPHIC
COMMUNICATIONS

ISSN: 2056-9890

Volume 75| Part 8| August 2019| Pages 1224-1227

https://doi.org/10.1107/S205698901900954X

Open

access

(E)-6,6′-(Diazene-1,2-diyl)bis(1,10-phenanthrolin-5-ol) trichloromethane disolvate: a superconjugated ligand

Muhib Ahmed,^a Michael Devereux,^b Vickie McKee,^c,^d Malachy McCann ^a and A. Denise Rooney ^a ^*

^aDepartment of Chemistry, Maynooth University, Co. Kildare, Ireland, ^bThe Centre for Biomimetic & Therapeutic Research, Focas Research Institute, Technological University Dublin, City Campus, Camden Row, Dublin 8, Ireland, ^cDepartment of Physics, Chemistry and Pharmacy, University of Southern Denmark, Canpusvej 55, 5230 Odense M, Denmark, and ^dSchool of Chemical Sciences, Dublin City University, Glasnevin, Dublin 9, Ireland
^*Correspondence e-mail: denise.rooney@mu.ie

Edited by J. Jasinski, Keene State College, USA (Received 7 June 2019; accepted 2 July 2019; online 23 July 2019)

Phenanthroline ligands are important metal-binding molecules which have been extensively researched for applications in both material science and medicinal chemistry. Azobenzene and its derivatives have received significant attention because of their ability to be reversibly switched between the E and Z forms and so could have applications in optical memory and logic devices or as molecular machines. Herein we report the formation and crystal structure of a highly unusual novel diazo-diphenanthroline compound, C₂₄H₁₄N₆O₂·2CHCl₃.

Keywords: crystal structure; diazo; phenanthroline; superconjugated ligand.

CCDC reference: 1937969

1. Chemical context

The chemical versatility of 1,10-phenanthroline (phen), its substituted derivatives and corresponding metal complexes (Bencini & Lippolis, 2010 ) is exemplified by their uses as organic light-emitting diodes (OLED)/electroluminescent display and solid-state lighting materials (Li et al., 2009 ), fluorescence molecular probes and imaging agents (Haraga et al., 2018 ), ion sensors (Zheng et al., 2012 ), solar energy converters (Freitag et al., 2016 ), anti-cancer and antimicrobial cytotoxins (McCann et al., 2012 ), DNA/RNA binding/cleavage (Kellett et al., 2011 ), enzyme inhibitors (Zhu et al., 2015 ), biomimetics (Casey et al., 1994 ) and catalysts (Lu et al., 2015 ). Given the resourcefulness of phenanthrolines, there is a continuing demand for new molecules containing this structural motif.

Herein, we detail the preparation and structural characterization of the purple diazo-diphenanthroline compound, (E)-6,6′-(diazene-1,2-diyl)bis(1,10-phenanthrolin-5-ol) (1), which was isolated in low yield from the reaction between 1,10-phenanthroline-5,6-dione (phendione) and isonicotinic acid hydrazide (isoniazid). Compound 1 crystallizes with two trichloromethane solvate molecules (1·2CHCl₃). The fully conjugated bis-phenanthroline molecule 1 is expected to offer exciting new physical and chemical properties as a stand-alone organic molecule, and it will also birth a plethora of interesting metal coordination complexes as a consequence of the dual N,N′-1,10-phenanthroline chelating moieties situated on the opposite ends of the molecule.

2. Structural commentary

Compound 1·2CHCl₃ crystallizes with two molecules of trichloromethane solvate per diazo-diphenanthroline (Fig. 1). The molecule lies on a centre of symmetry and is essentially planar, the r.m.s. deviation from the plane of the atoms in the ring system is 0.259 Å. The molecules lie parallel to the (5 7 15) or (5 $[\overline{7}]$ 14) planes. There is a hydrogen bond between the alcohol and the diazo linker [O1⋯N2 = 2.540 (3) Å under symmetry operation −x + 2, −y + 1, −z + 1, Table 1] and the trichloromethane molecule is oriented by a bifurcated C—H⋯·N interaction with the phenanthroline moiety [3.219 (3) and 3.136 (4) Å to N1 and N3, respectively]. The carbon atom of the trichloromethane molecule (C21) is 1.045 (3) Å from the mean plane of 1·2CHCl₃. There are 40 examples in the Cambridge Structural Database (CSD, Version 5.40, update of May 2019; Groom et al., 2016 ) showing similar interactions between trichloromethane and 1,10-phenanthroline derivatives and the geometry for 1·2CHCl₃ is typical of the group [mean Cl₃CH⋯·N = 3.18 (5) Å].

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
O1—H1A⋯N2ⁱ	0.88 (3)	1.74 (3)	2.540 (3)	149 (3)
C21—H21⋯N1	1.00	2.36	3.219 (3)	143
C21—H21⋯N3	1.00	2.33	3.136 (4)	137
Symmetry code: (i) -x+2, -y+1, -z+1.

Figure 1
Perspective view of 1·2CHCl₃ showing the labelling scheme for the asymmetric unit with displacement ellipsoids drawn at the 50% probability level. Hydrogen atoms are shown as spheres of arbitrary radius and C—H⋯N hydrogen bonds are indicated by dashed red lines.

The bond lengths indicate some delocalization through the central part of the molecule. The C6—O1and C5—N2 bonds are short [1.318 (3) and 1.376 (3) Å, respectively] and the N=N bond, at 1.316 (4) Å, is significantly longer than in most free diazo molecules [mean of 1.24 (4) Å for 2730 CSD entries].

3. Supramolecular features

Fig. 2 shows the unit-cell packing, the molecules lie parallel to the (5 7 15) or (5 $[\overline{7}]$ 14) planes with a mean interplanar distance of 3.228 (2) Å (under 1 − x, 1 − y, 1 − z) and the axis of the stack runs parallel to the a axis. The shortest ring centroid–centroid distance is 3.5154 (15) Å between the C₆ rings; however, there is a more direct overlap between the diazo group and an imine group in the next layer (ca 3.246 Å between the mid-point of the N=N bond and the mid-point of the C11=N3 bond under symmetry operation 1 − x, 1 − y, 1 − z) (Fig. 3). The most notable interactions between stacks are type 1 R—Cl⋯·Cl—R packing interactions (Mukherjee et al., 2014 ; Cavallo et al., 2016 ), the shortest Cl⋯Cl distance being 3.5353 (11) Å for Cl1⋯·Cl3 under symmetry operation −1 + x, y, z.

Figure 2
Unit-cell packing diagram viewed parallel to the plane of 1·2CHCl₃. Hydrogen atoms not involved in hydrogen bonding have been omitted for clarity.

Figure 3
Principal intermolecular interactions in 1·2CHCl₃. Purple spheres represent ring centroids and orange spheres show bond mid-points; distances in Å.

4. Database survey

There are three published examples of molecules containing the 2,2′-dihydroxyazobenzene core (Bougueria et al., 2014 ; Evangelio et al., 2008 ; Schilde et al., 1994 ) and all of these are significantly less delocalized than 1·2CHCl₃.

5. Spectroscopy studies of 1 in solution

Compound 1 has a very low solubility in all organic solvents investigated (CH₃Cl, CH₂Cl₂, DMSO, CH₃CN and alcohols). UV/vis spectra of 1·2CHCl₃ recorded in ethanol, methanol, CHCl₃ and CH₂Cl₂ are given in Fig. 4. Compound 1 exhibits significant solvatochromism showing a broad band in CHCl₃ and CH₂Cl₂ with λ_max at 543 nm. This band undergoes a bathochromic shift and separates into two bands in the alcohols with λ_max values at 643 nm and 600 nm in ethanol and at 636 nm and 591 nm in methanol. No accurate measurement of the extinction coefficient could be made as 1 was not fully soluble in the solvents and precipitation from the solvent occurred upon standing. The solubility of 1 was so low that only a very poorly resolved ¹H NMR of the compound was obtained in d⁴-methanol showing a series of peaks in the region expected for the phenanthroline H-atom signals and no definitive assignments of the peaks could be made. Interestingly, 1 was more soluble in strongly acidic solutions due to the protonation of one or more of the N atoms. Compound 1 dissolved in CF₃COOD to form a bright-red solution. Six signals are observed in the ¹H NMR spectrum in the region associated with the phenanthroline peaks. This finding is consistent with a compound which has a centre of symmetry, as found for the crystal structure, and suggests that at room temperature 1 remains in the E form in this solvent.

Figure 4
UV/vis spectra of 1·2CHCl₃ in (^____) CHCl₃, (- - - -) ethanol, (^____) CH₂Cl₂, and (⋯⋯) methanol. The absorbance axis is ×10 for the CHCl₃ and CH₂Cl₂ solutions.

6. Synthesis and crystallization

The mechanism to form 1 from the reaction mixture is unclear; however, the formation of isonicotinic acid N′-(pyridine-4-carbonyl)-hydrazide (2) from the mixture is an indication that radical chemistry is occurring. Isoniazid is well known to react to form radical species and these radicals are important in its role as an anti-tuberculosis drug (Timmins et al. 2006 ). Significantly one LC–MS study has shown that isoniazid will photo-degrade to form 2 (Fig. 5) and radical intermediates are proposed in its formation (Bhutani, 2007 ). Attempts were made to try to favour the formation of 1 using UV irradiation and the radical initiators azobisisobutyronitrile and 2,2′-azobis(2-amidinopropane) dihydrochloride but these were unsuccessful. However, although the reaction to form 1 was low yielding, attempts to make 1 by reaction of 6-amino-1,10-phenanthrolin-5-ol and 6-nitroso-1,10-phenananthrolin-5-ol using known conditions to form diazo compounds (Zhao et al. 2011 ) did not form the desired product. Studies are ongoing to improve the yield of the reaction to form 1.

Figure 5
Chemical structure of 2

Phendione (0.210 g, 1.000 mmol) was added to solution of isoniazid (0.137 g, 1.000 mmol) in EtOH (25 cm³). p-Tolouenesulfonic acid (10%, 0.02 g) was added and the solution refluxed for 6 h. The resulting suspension was filtered whilst hot and the filtrate allowed to stand in the dark overnight. Precipitated yellow (Z)-N′-(6-oxo-1,10-phenanthrolin-5(6H) ylidene)isonicotinohydrazide (0.263 g, 0.799 mmol, 80%) was filtered off and the bright-orange filtrate was concentrated to ca 10 cm³ using rotary evaporation and then allowed to stand in the dark. Over a period of four weeks, the bright-orange filtrate changed to a dark-green suspension. This mixture was heated to reflux and filtered whilst hot to give a green filtrate (see below) and a dark-purple powder. The powder was dissolved in CHCl₃ and allowed to crystallize over several days to produce dark-purple crystals of (E)-6,6′-(diazene-1,2-diyl)bis(1,10-phenanthrolin-5-ol) trichloromethane disolvate (1·2CHCl₃) (0.026 g, 0.039 mmol, 6.2% based on isoniazid starting material). Upon leaving the above green filtrate to evaporate further white isonicotinic acid N′-(pyridine-4-carbonyl)-hydrazide (compound 2) precipitated. The supernatent was decanted off and the solid dissolved in hot acetone. This colourless solution was evaporated to dryness on a rotary evaporator to give 2 (0.015 g, 0.062 mmol, 12.4% based on isoniazid starting material).

Compound 1: IR (ATR, cm⁻¹) (1.2CHCl₃): 3065, 2108, 1583, 1568, 1500, 1472, 1415, 1338, 1284, 1227, 1162, 1027, 795, 739, 717. ¹H NMR (protonated-1) (CF₃COOD, 500 MHz): δ 9.60 (d, J = 8.5 Hz, 2H), PhenH 9.56 (d, J = 8.5 Hz, 2H, PhenH), 9.47 (d, J = 5.0 Hz, 2H, PhenH), 9.37 (d, J = 5.0 Hz, 2H, PhenH), 8.57 (dd, J = 8.5, 5.0 Hz, 2H, PhenH), 8.38 (dd, J = 8.5, 5.0 Hz, 2H, PhenH), 4.12 (s, 2H, OH). Elemental analysis calculated for 1·2CHCl₃ (C₂₆H₁₆Cl₆N₆O₂, 657.15 g mol⁻¹): C 47.52, H 2.45, N 12.79%; found: C 47.73, H 2.52, N 12.77%.

Compound 2 has been previously reported (Quiroga et al., 2008 ; Bhutani et al., 2007) and the characterization data given are consistent with the data recorded in the present study.

Compound 2: IR (KBr, cm⁻¹) 3435, 3210, 3045, 1682, 1642, 1546, 1489, 1406, 1299, 838, 751. ¹H NMR (CD₃OD, 500 MHz): δ 8.80 (d, J = 5 Hz, 2H), 7.42 (d, J = 5 Hz, 2H). ¹³C NMR (CD₃OD, 125 MHz): δ 165.6 (C=O), 150.0 (PyrC), 140.5 (PyrC), 121.8 (PyrC). MS: Calculated m/z for C₁₂H₁₀N₄O₂: (M + H)⁺ 243.0877; found: (M + H)⁺ 243.0882; difference (ppm): 2.15.

7. Refinement

Crystal data, data collection and structure refinement details are summarized in Table 2. The C-bound H atoms were included in calculated positions and treated as riding, with C—H = 0.95–1.00 Å and U_iso(H) = 1.5U_eq(C) for methyl H atoms or 1.2U_eq(C) otherwise. The H atom (H1A) bonded to oxygen was located in a difference-Fourier map and its coordinates were refined with U_iso(H) = 1.5U_eq(O).

Table 2
Experimental details

Crystal data
Chemical formula	C₂₄H₁₄N₆O₂·2CHCl₃
M_r	657.15
Crystal system, space group	Monoclinic, P2₁/c
Temperature (K)	150
a, b, c (Å)	5.9406 (7), 18.856 (2), 12.2375 (16)
β (°)	96.863 (4)
V (Å³)	1361.0 (3)
Z	2
Radiation type	Mo Kα
μ (mm⁻¹)	0.67
Crystal size (mm)	0.43 × 0.05 × 0.04

Data collection
Diffractometer	Bruker–Nonius X8 APEXII CCD
Absorption correction	Multi-scan (SADABS; Sheldrick, 2012 )
T_min, T_max	0.657, 0.745
No. of measured, independent and observed [I > 2σ(I)] reflections	18529, 2732, 2068
R_int	0.045
(sin θ/λ)_max (Å⁻¹)	0.620

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.044, 0.111, 1.03
No. of reflections	2732
No. of parameters	184
H-atom treatment	Heteroxyz
Δρ_max, Δρ_min (e Å⁻³)	0.87, −0.59
Computer programs: APEX2 and SAINT (Bruker, 2010 ), SHELXT (Sheldrick 2015a ), SHELXL2018 (Sheldrick, 2015b ), Mercury (Macrae et al., 2008 ) and publCIF (Westrip, 2010 ).

Supporting information

CCDC reference: 1937969

Crystal structure: contains datablock I. DOI: https://doi.org/10.1107/S205698901900954X/jj2213sup1.cif

Structure factors: contains datablock I. DOI: https://doi.org/10.1107/S205698901900954X/jj2213Isup2.hkl

Supporting information file. DOI: https://doi.org/10.1107/S205698901900954X/jj2213Isup3.cml

checkCIF report

Computing details top

Data collection: APEX2 (Bruker, 2010); cell refinement: SAINT (Bruker, 2010); data reduction: SAINT (Bruker, 2010); program(s) used to solve structure: SHELXT (Sheldrick 2015a); program(s) used to refine structure: SHELXL2018 (Sheldrick, 2015b); molecular graphics: Mercury (Macrae et al., 2008); software used to prepare material for publication: publCIF (Westrip, 2010).

(E)-6,6'-(Diazene-1,2-diyl)bis(1,10-phenanthrolin-5-ol) trichloromethane disolvate top

Crystal data top

C₂₄H₁₄N₆O₂·2CHCl₃	F(000) = 664
M_r = 657.15	D_x = 1.604 Mg m⁻³
Monoclinic, P2₁/c	Mo Kα radiation, λ = 0.71073 Å
a = 5.9406 (7) Å	Cell parameters from 5155 reflections
b = 18.856 (2) Å	θ = 2.7–26.1°
c = 12.2375 (16) Å	µ = 0.67 mm⁻¹
β = 96.863 (4)°	T = 150 K
V = 1361.0 (3) Å³	Lath, purple
Z = 2	0.43 × 0.05 × 0.04 mm

Data collection top

Bruker–Nonius X8 APEXII CCD diffractometer	2732 independent reflections
Radiation source: fine-focus sealed-tube	2068 reflections with I > 2σ(I)
Detector resolution: 9.1 pixels mm^-1	R_int = 0.045
thin–slice ω and φ scans	θ_max = 26.2°, θ_min = 2.7°
Absorption correction: multi-scan (SADABS; Sheldrick, 2012)	h = −5→7
T_min = 0.657, T_max = 0.745	k = −23→23
18529 measured reflections	l = −15→14

Refinement top

Refinement on F²	Primary atom site location: dual
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F² > 2σ(F²)] = 0.044	Hydrogen site location: mixed
wR(F²) = 0.111	Heteroxyz
S = 1.02	w = 1/[σ²(F_o²) + (0.0444P)² + 1.8407P] where P = (F_o² + 2F_c²)/3
2732 reflections	(Δ/σ)_max = 0.001
184 parameters	Δρ_max = 0.87 e Å⁻³
0 restraints	Δρ_min = −0.59 e Å⁻³

Special details top

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.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å²) top

	x	y	z	U_iso*/U_eq
N1	0.3174 (4)	0.63628 (11)	0.66898 (18)	0.0216 (5)
C1	0.3648 (5)	0.69741 (14)	0.6234 (2)	0.0240 (6)
H1	0.269904	0.736919	0.632910	0.029*
C2	0.5456 (5)	0.70706 (14)	0.5623 (2)	0.0255 (6)
H2	0.572645	0.752054	0.531450	0.031*
C3	0.6846 (4)	0.65044 (14)	0.5473 (2)	0.0219 (6)
H3	0.810516	0.656051	0.507047	0.026*
C4	0.6383 (4)	0.58421 (13)	0.5923 (2)	0.0174 (5)
C5	0.7702 (4)	0.52078 (13)	0.5757 (2)	0.0177 (5)
N2	0.9396 (3)	0.52817 (11)	0.50912 (17)	0.0195 (5)
C6	0.7175 (4)	0.45623 (14)	0.6231 (2)	0.0195 (5)
O1	0.8303 (3)	0.39726 (10)	0.61010 (16)	0.0246 (4)
H1A	0.937 (6)	0.4088 (17)	0.569 (3)	0.037*
C7	0.5313 (4)	0.45226 (13)	0.6889 (2)	0.0191 (5)
C8	0.4726 (5)	0.38783 (14)	0.7366 (2)	0.0239 (6)
H8	0.554738	0.345644	0.726050	0.029*
C9	0.2948 (5)	0.38714 (15)	0.7985 (2)	0.0274 (6)
H9	0.251833	0.344474	0.831710	0.033*
C10	0.1781 (5)	0.45015 (15)	0.8118 (2)	0.0253 (6)
H10	0.057433	0.449191	0.856178	0.030*
N3	0.2257 (4)	0.51143 (12)	0.76615 (18)	0.0224 (5)
C11	0.4006 (4)	0.51294 (13)	0.7050 (2)	0.0182 (5)
C12	0.4522 (4)	0.58002 (13)	0.6541 (2)	0.0185 (5)
C21	0.0382 (5)	0.64497 (15)	0.8784 (2)	0.0271 (6)
H21	0.087592	0.621547	0.811921	0.032*
Cl1	−0.23375 (13)	0.61485 (6)	0.89683 (7)	0.0493 (3)
Cl2	0.03861 (18)	0.73803 (4)	0.85952 (7)	0.0508 (3)
Cl3	0.23081 (12)	0.62261 (4)	0.99506 (6)	0.0333 (2)

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
N1	0.0234 (11)	0.0211 (12)	0.0208 (12)	0.0047 (9)	0.0050 (9)	−0.0007 (9)
C1	0.0290 (14)	0.0208 (15)	0.0229 (14)	0.0070 (11)	0.0065 (11)	−0.0003 (11)
C2	0.0330 (15)	0.0159 (13)	0.0279 (15)	0.0000 (11)	0.0054 (12)	0.0012 (11)
C3	0.0231 (13)	0.0216 (14)	0.0219 (14)	−0.0011 (11)	0.0064 (11)	−0.0016 (11)
C4	0.0192 (13)	0.0169 (13)	0.0160 (12)	0.0001 (10)	0.0008 (10)	−0.0016 (10)
C5	0.0158 (12)	0.0196 (13)	0.0169 (13)	0.0011 (10)	−0.0011 (10)	−0.0021 (10)
N2	0.0180 (11)	0.0213 (11)	0.0193 (11)	0.0023 (8)	0.0020 (9)	−0.0036 (9)
C6	0.0192 (13)	0.0203 (14)	0.0180 (13)	0.0023 (10)	−0.0011 (10)	−0.0020 (10)
O1	0.0258 (10)	0.0197 (10)	0.0293 (11)	0.0053 (8)	0.0072 (8)	0.0007 (8)
C7	0.0212 (13)	0.0203 (13)	0.0151 (13)	0.0003 (10)	−0.0007 (10)	0.0007 (10)
C8	0.0277 (14)	0.0199 (14)	0.0236 (14)	0.0023 (11)	0.0004 (11)	0.0027 (11)
C9	0.0319 (15)	0.0274 (15)	0.0230 (14)	−0.0046 (12)	0.0036 (12)	0.0063 (12)
C10	0.0244 (14)	0.0290 (15)	0.0236 (14)	−0.0027 (11)	0.0077 (11)	0.0032 (12)
N3	0.0235 (11)	0.0250 (12)	0.0190 (11)	−0.0009 (9)	0.0039 (9)	0.0005 (9)
C11	0.0207 (13)	0.0198 (13)	0.0141 (12)	0.0010 (10)	0.0016 (10)	−0.0020 (10)
C12	0.0199 (13)	0.0196 (13)	0.0156 (13)	0.0008 (10)	0.0008 (10)	−0.0015 (10)
C21	0.0290 (15)	0.0290 (16)	0.0242 (15)	0.0014 (12)	0.0077 (12)	−0.0021 (12)
Cl1	0.0258 (4)	0.0875 (7)	0.0346 (5)	−0.0121 (4)	0.0037 (3)	−0.0095 (4)
Cl2	0.0818 (7)	0.0295 (4)	0.0438 (5)	0.0156 (4)	0.0196 (5)	0.0009 (4)
Cl3	0.0273 (4)	0.0379 (4)	0.0339 (4)	−0.0051 (3)	0.0008 (3)	0.0002 (3)

Geometric parameters (Å, º) top

N1—C1	1.326 (3)	O1—H1A	0.88 (3)
N1—C12	1.355 (3)	C7—C11	1.409 (4)
C1—C2	1.392 (4)	C7—C8	1.409 (4)
C1—H1	0.9500	C8—C9	1.371 (4)
C2—C3	1.375 (4)	C8—H8	0.9500
C2—H2	0.9500	C9—C10	1.395 (4)
C3—C4	1.405 (4)	C9—H9	0.9500
C3—H3	0.9500	C10—N3	1.328 (3)
C4—C12	1.414 (3)	C10—H10	0.9500
C4—C5	1.457 (3)	N3—C11	1.352 (3)
C5—N2	1.376 (3)	C11—C12	1.459 (4)
C5—C6	1.400 (4)	C21—Cl1	1.752 (3)
N2—N2ⁱ	1.316 (4)	C21—Cl2	1.770 (3)
C6—O1	1.318 (3)	C21—Cl3	1.771 (3)
C6—C7	1.446 (4)	C21—H21	1.0000

C1—N1—C12	117.7 (2)	C8—C7—C6	121.2 (2)
N1—C1—C2	123.8 (2)	C9—C8—C7	118.8 (2)
N1—C1—H1	118.1	C9—C8—H8	120.6
C2—C1—H1	118.1	C7—C8—H8	120.6
C3—C2—C1	118.9 (3)	C8—C9—C10	118.9 (3)
C3—C2—H2	120.5	C8—C9—H9	120.6
C1—C2—H2	120.5	C10—C9—H9	120.6
C2—C3—C4	119.3 (2)	N3—C10—C9	123.9 (2)
C2—C3—H3	120.3	N3—C10—H10	118.0
C4—C3—H3	120.3	C9—C10—H10	118.0
C3—C4—C12	117.4 (2)	C10—N3—C11	117.9 (2)
C3—C4—C5	122.8 (2)	N3—C11—C7	122.2 (2)
C12—C4—C5	119.8 (2)	N3—C11—C12	118.0 (2)
N2—C5—C6	123.3 (2)	C7—C11—C12	119.8 (2)
N2—C5—C4	116.3 (2)	N1—C12—C4	122.7 (2)
C6—C5—C4	120.4 (2)	N1—C12—C11	117.6 (2)
N2ⁱ—N2—C5	118.1 (3)	C4—C12—C11	119.6 (2)
O1—C6—C5	122.8 (2)	Cl1—C21—Cl2	110.73 (16)
O1—C6—C7	117.2 (2)	Cl1—C21—Cl3	109.64 (15)
C5—C6—C7	120.0 (2)	Cl2—C21—Cl3	109.29 (16)
C6—O1—H1A	106 (2)	Cl1—C21—H21	109.1
C11—C7—C8	118.3 (2)	Cl2—C21—H21	109.1
C11—C7—C6	120.4 (2)	Cl3—C21—H21	109.1

Symmetry code: (i) −x+2, −y+1, −z+1.

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
O1—H1A···N2ⁱ	0.88 (3)	1.74 (3)	2.540 (3)	149 (3)
C21—H21···N1	1.00	2.36	3.219 (3)	143
C21—H21···N3	1.00	2.33	3.136 (4)	137

Symmetry code: (i) −x+2, −y+1, −z+1.

Acknowledgements

We gratefully acknowledge Maynooth University for a John and Pat Hume Scholarship for MA.

Funding information

Funding for this research was provided by: National University of Ireland, Maynooth Hume Scholarship (scholarship to Muhib Ahmed).

References

Bencini, A. & Lippolis, V. (2010). Coord. Chem. Rev. 254, 2096–2180. CrossRef CAS Google Scholar
Bhutani, H., Singh, S., Vir, S., Bhutani, K. K., Kumar, R., Chakraborti, A. K. & Jindal, K. C. (2007). J. Pharm. Biomed. Anal. 43, 1213–1220. CrossRef PubMed CAS Google Scholar
Bougueria, H., Mili, A., Benosmane, A., Bouchoul, A. el kader & Bouaoud, S. (2014). Acta Cryst. E70, o225. Google Scholar
Bruker (2010). APEX2 and SAINT. Bruker AXS Inc., Madison, Wisconsin, USA. Google Scholar
Casey, M. T., McCann, M., Devereux, M., Curran, M., Cardin, C., Convery, M., Quillet, V. & Harding, C. (1994). J. Chem. Soc. Chem. Commun. pp. 2643–2645. CrossRef Google Scholar
Cavallo, G., Metrangolo, P., Milani, R., Pilati, T., Priimagi, A., Resnati, G. & Terraneo, G. (2016). Chem. Rev. 116, 2478–2601. Web of Science CrossRef CAS PubMed Google Scholar
Evangelio, E., Saiz-Poseu, J., Maspoch, D., Wurst, K., Busque, F. & Ruiz-Molina, D. (2008). Eur. J. Inorg. Chem. 14, 2278–2285. CSD CrossRef Google Scholar
Freitag, M., Giordano, F., Yang, W., Pazoki, M., Hao, Y., Zietz, B., Grätzel, M., Hagfeldt, A. & Boschloo, G. (2016). J. Phys. Chem. C, 120, 9595–9603. Web of Science CrossRef CAS Google Scholar
Groom, C. R., Bruno, I. J., Lightfoot, M. P. & Ward, S. C. (2016). Acta Cryst. B72, 171–179. Web of Science CrossRef IUCr Journals Google Scholar
Haraga, T., Ouchi, K., Sato, Y., Hoshino, H., Tanaka, R., Fujihara, T., Kurokawa, H., Shibukawa, M., Ishimori, K. I., Kameo, Y. & Saito, S. (2018). Anal. Chim. Acta, 1032, 188–196. CrossRef CAS PubMed Google Scholar
Kellett, A., O'Connor, M., McCann, M., McNamara, M., Lynch, P., Rosair, G., McKee, V., Creaven, B., Walsh, M., McClean, S., Foltyn, A., O'Shea, D., Howe, O. & Devereux, M. (2011). Dalton Trans. 40, 1024–1027. CSD CrossRef CAS PubMed Google Scholar
Li, Y.-J., Sasabe, H., Su, S.-J., Tanaka, D., Takeda, T., Pu, Y.-J. & Kido, J. (2009). Chem. Lett. 38, 712–713. CrossRef CAS Google Scholar
Lu, Y., Wang, X., Wang, M., Kong, L. & Zhao, J. (2015). Electrochim. Acta, 180, 86–95. CrossRef CAS Google Scholar
Macrae, C. F., Bruno, I. J., Chisholm, J. A., Edgington, P. R., McCabe, P., Pidcock, E., Rodriguez-Monge, L., Taylor, R., van de Streek, J. & Wood, P. A. (2008). J. Appl. Cryst. 41, 466–470. Web of Science CrossRef CAS IUCr Journals Google Scholar
McCann, M., Santos, A., da Silva, B., Romanos, M., Pyrrho, A., Devereux, M., Kavanagh, K., Fichtner, I. & Kellett, A. (2012). Toxicol. Res. 1, 47–54. CrossRef CAS Google Scholar
Mukherjee, A., Tothadi, S. & Desiraju, G. R. (2014). Acc. Chem. Res. 47, 2514–2524. Web of Science CrossRef CAS PubMed Google Scholar
Quiroga, J., Portilla, J., Abonía, R., Insuasty, B., Nogueras, M. & Cobo, J. (2008). Tetrahedron Lett. 49, 5943–5945. Web of Science CrossRef CAS Google Scholar
Schilde, U., Hefele, H., Ludwig, E. & Uhlemann, E. (1994). Cryst. Res. Technol. 29, 393–396. CSD CrossRef CAS Google Scholar
Sheldrick, G. M. (2012). SADABS. University of Göttingen, Germany. Google Scholar
Sheldrick, G. M. (2015a). Acta Cryst. A71, 3–8. Web of Science CrossRef IUCr Journals Google Scholar
Sheldrick, G. M. (2015b). Acta Cryst. C71, 3–8. Web of Science CrossRef IUCr Journals Google Scholar
Timmins, G. S. & Deretic, V. (2006). Mol. Microbiol. 62, 1220–1227. Web of Science CrossRef PubMed CAS Google Scholar
Westrip, S. P. (2010). J. Appl. Cryst. 43, 920–925. Web of Science CrossRef CAS IUCr Journals Google Scholar
Zhao, R., Tan, C., Xie, Y., Gao, C., Liu, H. & Jiang, Y. (2011). Tetrahedron Lett. 52, 3805–3809. CrossRef CAS Google Scholar
Zheng, Y., Tan, C., Drummen, G. P. & Wang, Q. (2012). Spectrochim. Acta A Mol. Biomol. Spectrosc. 96, 387–394. CrossRef CAS PubMed Google Scholar
Zhu, Y., Liao, Y., Zhang, L. & Bai, X. (2015). PCT Int. Appl. WO 2015154716 A1. Google Scholar

This is an open-access article distributed under the terms of the Creative Commons Attribution (CC-BY) Licence, which permits unrestricted use, distribution, and reproduction in any medium, provided the original authors and source are cited.