Synthesis, crystal structure and anti­fungal activity of a divalent cobalt(II) complex with uniconazole

Azole compounds have attracted commercial inter­est due to their high bac­tericidal and plant-growth-regulating activities. Uniconazole [or 1-(4-chloro­phen­yl)-4,4-dimethyl-2-(1H-1,2,4-triazol-1-yl)pent-1-en-3-ol] is a highly active 1,2,4-triazole fungicide and plant-growth regulator with low toxicity. The pharmacological and toxicological properties of many drugs are modified by the formation of their metal complexes. Therefore, there is much inter­est in exploiting the coordination chemistry of triazole pesticides and their potential application in agriculture. However, reports of complexes of uniconazole are rare. A new cobalt(II) complex of uniconazole, namely di­chlorido­tetra­kis­[1-(4-chloro­phen­yl)-4,4-dimethyl-2-(1H-1,2,4-triazol-1-yl-[kappa]N⁴)pent-1-en-3-ol]cobalt(II), [CoCl₂(C₁₅H₁₈ClN₃O)₄], was synthesized and structurally characterized by element analysis, IR spectrometry and X-ray single-crystal diffraction. The crystal structural analysis shows that the Co^II atom is located on the inversion centre and is coordinated by four uniconazole and two chloride ligands, forming a distorted octa­hedral geometry. The hy­droxy groups of an uniconazole ligands of adjacent mol­ecules form hydrogen bonds with the axial chloride ligands, resulting in one-dimensional chains parallel to the a axis. The complex was analysed for its anti­fungal activity by the mycelial growth rate method. It was revealed that the anti­fungal effect of the title complex is more pronounced than the effect of fungicide uniconazole for Botryosphaeria ribis, Wheat gibberellic and Grape anthracnose.

S1. Introduction

During the 1970s, azole compounds attracted commercial inter­est due to their high bactericidal (Hadjikakou et al., 2005; Zhang et al., 2008) and plant-growth-regulating activities (Chapeland et al., 1999; Wu et al., 2013). Uniconazole [or 1-(4-chloro­phenyl)-4,4-di­methyl-2-(1H-1,2,4-triazol-1-yl)pent-1-en-3-ol, L], a highly active 1,2,4-triazole fungicide (Fletcher et al., 2000; Todoroki et al., 2008; Assuero & Tognetti, 2010) and plant growth regulator with low toxicity (Jewiss, 1972), was successfully developed as a kind of triazole plant growth regulator by the Sumitomo Chemical Corporation of Japan in the early 1980s (Chang et al., 2013). As an effective plant growth regulator, it has been used in many crops in the world because of its strong ability to dwarf plants [OK?] and it is mainly applied to the seed treatment (Fletcher & Hofstra, 1990; Rajala & Peltonen-Sainio, 2001; Abdul Jaleel et al., 2008; Schluttenhofer et al., 2011) or liquid spray of rice, wheat, peanuts, fruit, tobacco and other crops. Furthermore, as an effective fungicide, it has a suppression killing effect on a variety of crop diseases, such as wheat root rot, corn leaf blight, wheat gibberellic disease, bean anthracnose (Kataoka et al., 2003), and so on. The synthesis of triazole ligands and their inter­action with metal ions have been highly anti­cipated because of their rich and versatile coordination modes. The pharmacological and toxicological properties of many drugs were modified in the form of metallic complexes (Zhu et al., 2000; Beckmann & Brooker, 2003; Klingele, Moubaraki et al., 2005; Klingele, Boyd et al., 2005; Lu et al., 2010). Therefore, there is strong inter­est in exploiting the coordination chemistry of triazole pesticides and their potential application in agriculture. Even though the complexes of triadimefon, diniconazole and tebuconazole with metal ions have been proposed (Zhang & Wu, 2005; Nie et al., 2012; Li, Xi, Yan, Yang et al., 2015), the complex of uniconazole has, to the best of our knowledge, rarely been reported. The title complex, [CoCl₂L₄], (1), has been synthesized from cobalt chloride and uniconazole. We have determined the crystal structure of [CoCl₂L₄] and compared the anti­fungal activity of the Co^II coordination compound with the pesticide uniconazole. The microbial results show that the anti­fungal activity of metal coordination compound is greatly improved for Botryosphaeria ribis, Wheat gibberellic and Grape anthracnose compared to the conventional triazole fungicide uniconazole.

S2. Experimental

Uniconazole was purchased from a commercial source and used after repeated recrystallization. CoCl₂.6H₂O and other rea­cta­nts were of laboratory reagent grade. Elemental analysis for C, H and N was performed on an ELEMENTAR Vario EL III elemental analyzer. The IR (KBr pellets) spectra were recorded in the 400–4000 cm^-1 range using a Bruker EQUINOX 55 FT–IR spectrometer.

S2.1. Synthesis and crystallization

An ethanol solution (10 ml) of uniconazole (0.5836 g, 2 mmol) was added dropwise to an ethano­lic solution (5 ml) of CoCl₂.6H₂O (0.2379 g, 1 mmol). After stirring for 4 h at room temperature, the reaction liquid was filtered and red block-shaped crystals suitable for X-ray analysis were obtained by slow evaporation of the ethanol solution after 10 d (yield 80%, based on CoCl₂). Analysis calculated for C₆₀H₇₂Cl₆CoN₁₂O₄ (%): C 55.56, H 5.60, N 12.95; found: C 55.51, H 5.69, N 12.88. IR (KBr, ν/cm^-1): 3409 (w), 3166 (w), 2972 (s), 1645 (w), 1478 (w), 1401 (m), 1232 (m), 1068 (vs), 874 (m), 824 (w), 670 (m).

S2.2. Refinement

Crystal data, data collection and structure refinement details are summarized in Table 1. H atoms bonded to C atoms and hy­droxy O atoms were placed at calculated positions and refined using a riding-model approximation, with C—H = 0.96 Å and O—H = 0.82 Å, and with U_iso(H) = 1.5U_eq(C,O) for methyl and hy­droxy H atoms, and 1.2U_eq(C) for all other H atoms.

S2.3. Biological experiments

The inhibitory effects of uniconazole and the title cobvalt(II) complex on fungi were evaluated based on the values of the inhibition rate and EC₅₀. The higher the inhibition rate, the better the anti­fungal activity of the compound will be. On the contrary, the lower the value of EC₅₀, the more effective the sterilization effect will be. Four microorganisms, namely Botryosphaeria ribis, (I), Botryosphaeria berengriana, (II), Wheat gibberellic, (III), and Grape anthracnose, (IV), were selected for anti­fungal activity studies. The anti­fungal activities of uniconazole, the synthesized complex and the metal salt CoCl₂.6H₂O were carried out by the mycelial growth rate method (Zhang et al., 2010; Xiong et al., 2014). The fungi were cultured on potato dextrose agar (PDA) plates at 301 K for 5 d prior to use. After sterilized for 30 min at 393 K, PDA was cooled to 323 K and poured into petri dishes (7.5 cm in diameter). The PDA was mixed well with various concentrations of these target compounds (0.5, 1, 2 and 4 mg l^-1) successively. The prepared phytopathogens were inoculated in each well of 7 mm diameter (made with a borer), and then the fungi strains were cultured at 301 K for 72 h. Parallel controls were maintained with PDA medium. The diameter of the fungal colonies on the PDA plates was measured after 72 h.

S3. Results and discussion

The title cobalt(II) complex crystallizes in the triclinic P1 space group and the coordination environment of the Co^II ion is six-coordinated by four triazole-ring N atoms [N1, N1ⁱ, N4 and N4ⁱ; symmetry code: (i) -x, -y+1, -z+1] from four equivalent uniconazole ligands, forming the equatorial plane, and by two chloride ligands in axial positions, as shown in Fig. 1. The least-squares plane equation of the equatorial plane including Co atom is 6.931x - 4.973y + 7.274z = 1.1504, and the mean deviation from the plane is 0.000 Å, indicating that these five atoms form a perfect plane. The Co1—N1 and Co1—N4 bond lengths (Table 2) are in agreement with corresponding bond lengths reported in the literature for the [Co(L²)(DMF)₂] [L² is penta­dentate 2,6-di­acetyl­pyridine bis­(4-acyl­hydrazone; Co—N = 2.157–2.230 Å; Gök?e et al., 2015] and [Co(L³)₄(H₂O)₂](NO₃)₂.2H₂O [L³ is diniconazole; Co—N = 2.1392–2.1454 Å; Xi et al., 2015]. In addition to the crystallographically imposed inversion symmetry, the coordination of the Co^II atom is nearly C2, as shown in Fig. 1.

As shown in Fig. 2, adjacent [CoCl₂L₄] molecules are linked into one-dimensional chain via two kinds of inter­molecular hydrogen bonds, viz. O1—H1···Cl1ⁱⁱ and O2—H2···Cl1ⁱⁱ (Table 3), along the a axis, the hy­droxy O1 and O2 atoms acting as hydrogen-bond donors to chloride atom Cl1 from neighbouring molecules. The one-dimensional chain is generated in the same way as in the structure of [CuCl₂L₄] (L = uniconazole; Hu et al., 2014), whose one-dimensional chain is also generated by inter­molecular O—H···Cl hydrogen bonds between hy­droxy groups and coordinated chloride anions. The crystal packing of [CoCl₂L₄] is shown in Fig. 3.

According to anti­fungal screening data, the title cobalt(II) complex shows a higher inhibition effect than both uniconazole and CoCl₂ (Fig. 4 and Table 4). Uniconazole itself displays excellent anti­fungal activity against Botryosphaeria berengriana, (II); the inhibition rate of uniconazole is up to 99.70% at a concentration of 4.0 mg l^-1, so the anti­fungal activity increases a little when coordinating with CoCl₂, which reveals that uniconazole has a specificity for Botryosphaeria berengriana. Meanwhile, the inhibitory effects of complex (1) on Botryosphaeria ribis, (I), Wheat gibberellic, (III), and Grape anthracnose, (IV), are quite obvious; the inhibition rates have increased significantly, as shown in Fig. 4. Based on Table 4, cobalt(II) complex (1) has the best inhibitory activity on Grape anthracnose, (VI), whose toxicity was 11.54 times higher than that of uniconazole. As for the other two fungi, i.e. (I) and (III), the toxicity of [CoCl₂L₄] is enhanced by 9.77 and 4.10 times, respectively, compared to uniconazole. This increased activity of complex (1) can be explained on the basis of chelation theory. On chelation, the polarity of the metal cation is reduced to a great extent due to the overlap with the ligand orbital. Furthermore, this increases the delocalization of π-electrons over the whole chelate ring and enhances the lipophilicity of the complex (Chaudhary et al., 2003; Li, Xi, Yan, Guan et al., 2015), thus the anti­fungal effect of [CoCl₂L₄] is greatly improved compared to the conventional triazole fungicide uniconazole.

In this paper, a Co^II complex of uniconazole was synthesized and its structure confirmed. The results showed that it belongs to the triclinic system (P1 space group). The Co^II atom adopts a distorted o­cta­hedral geometry, where the equatorial plane is occupied by four triazole-ring N atoms from four equivalent uniconazole ligands and the axial positions are occupied by two chloride ligands. Adjacent [CoCl₂L₄] molecules are linked by O—H···Cl hydrogen bonds to form a one-dimensional chain. The anti­fungal activity of the complex was determined by the mycelial growth rate method. It is found that the anti­fungal activity for Botryosphaeria ribis, Wheat gibberellic and Grape anthracnose is greatly improved compared to the conventional triazole fungicide uniconazole.

Structure description

During the 1970s, azole compounds attracted commercial inter­est due to their high bactericidal (Hadjikakou et al., 2005; Zhang et al., 2008) and plant-growth-regulating activities (Chapeland et al., 1999; Wu et al., 2013). Uniconazole [or 1-(4-chloro­phenyl)-4,4-di­methyl-2-(1H-1,2,4-triazol-1-yl)pent-1-en-3-ol, L], a highly active 1,2,4-triazole fungicide (Fletcher et al., 2000; Todoroki et al., 2008; Assuero & Tognetti, 2010) and plant growth regulator with low toxicity (Jewiss, 1972), was successfully developed as a kind of triazole plant growth regulator by the Sumitomo Chemical Corporation of Japan in the early 1980s (Chang et al., 2013). As an effective plant growth regulator, it has been used in many crops in the world because of its strong ability to dwarf plants [OK?] and it is mainly applied to the seed treatment (Fletcher & Hofstra, 1990; Rajala & Peltonen-Sainio, 2001; Abdul Jaleel et al., 2008; Schluttenhofer et al., 2011) or liquid spray of rice, wheat, peanuts, fruit, tobacco and other crops. Furthermore, as an effective fungicide, it has a suppression killing effect on a variety of crop diseases, such as wheat root rot, corn leaf blight, wheat gibberellic disease, bean anthracnose (Kataoka et al., 2003), and so on. The synthesis of triazole ligands and their inter­action with metal ions have been highly anti­cipated because of their rich and versatile coordination modes. The pharmacological and toxicological properties of many drugs were modified in the form of metallic complexes (Zhu et al., 2000; Beckmann & Brooker, 2003; Klingele, Moubaraki et al., 2005; Klingele, Boyd et al., 2005; Lu et al., 2010). Therefore, there is strong inter­est in exploiting the coordination chemistry of triazole pesticides and their potential application in agriculture. Even though the complexes of triadimefon, diniconazole and tebuconazole with metal ions have been proposed (Zhang & Wu, 2005; Nie et al., 2012; Li, Xi, Yan, Yang et al., 2015), the complex of uniconazole has, to the best of our knowledge, rarely been reported. The title complex, [CoCl₂L₄], (1), has been synthesized from cobalt chloride and uniconazole. We have determined the crystal structure of [CoCl₂L₄] and compared the anti­fungal activity of the Co^II coordination compound with the pesticide uniconazole. The microbial results show that the anti­fungal activity of metal coordination compound is greatly improved for Botryosphaeria ribis, Wheat gibberellic and Grape anthracnose compared to the conventional triazole fungicide uniconazole.

Uniconazole was purchased from a commercial source and used after repeated recrystallization. CoCl₂.6H₂O and other rea­cta­nts were of laboratory reagent grade. Elemental analysis for C, H and N was performed on an ELEMENTAR Vario EL III elemental analyzer. The IR (KBr pellets) spectra were recorded in the 400–4000 cm^-1 range using a Bruker EQUINOX 55 FT–IR spectrometer.

The inhibitory effects of uniconazole and the title cobvalt(II) complex on fungi were evaluated based on the values of the inhibition rate and EC₅₀. The higher the inhibition rate, the better the anti­fungal activity of the compound will be. On the contrary, the lower the value of EC₅₀, the more effective the sterilization effect will be. Four microorganisms, namely Botryosphaeria ribis, (I), Botryosphaeria berengriana, (II), Wheat gibberellic, (III), and Grape anthracnose, (IV), were selected for anti­fungal activity studies. The anti­fungal activities of uniconazole, the synthesized complex and the metal salt CoCl₂.6H₂O were carried out by the mycelial growth rate method (Zhang et al., 2010; Xiong et al., 2014). The fungi were cultured on potato dextrose agar (PDA) plates at 301 K for 5 d prior to use. After sterilized for 30 min at 393 K, PDA was cooled to 323 K and poured into petri dishes (7.5 cm in diameter). The PDA was mixed well with various concentrations of these target compounds (0.5, 1, 2 and 4 mg l^-1) successively. The prepared phytopathogens were inoculated in each well of 7 mm diameter (made with a borer), and then the fungi strains were cultured at 301 K for 72 h. Parallel controls were maintained with PDA medium. The diameter of the fungal colonies on the PDA plates was measured after 72 h.

The title cobalt(II) complex crystallizes in the triclinic P1 space group and the coordination environment of the Co^II ion is six-coordinated by four triazole-ring N atoms [N1, N1ⁱ, N4 and N4ⁱ; symmetry code: (i) -x, -y+1, -z+1] from four equivalent uniconazole ligands, forming the equatorial plane, and by two chloride ligands in axial positions, as shown in Fig. 1. The least-squares plane equation of the equatorial plane including Co atom is 6.931x - 4.973y + 7.274z = 1.1504, and the mean deviation from the plane is 0.000 Å, indicating that these five atoms form a perfect plane. The Co1—N1 and Co1—N4 bond lengths (Table 2) are in agreement with corresponding bond lengths reported in the literature for the [Co(L²)(DMF)₂] [L² is penta­dentate 2,6-di­acetyl­pyridine bis­(4-acyl­hydrazone; Co—N = 2.157–2.230 Å; Gök?e et al., 2015] and [Co(L³)₄(H₂O)₂](NO₃)₂.2H₂O [L³ is diniconazole; Co—N = 2.1392–2.1454 Å; Xi et al., 2015]. In addition to the crystallographically imposed inversion symmetry, the coordination of the Co^II atom is nearly C2, as shown in Fig. 1.

As shown in Fig. 2, adjacent [CoCl₂L₄] molecules are linked into one-dimensional chain via two kinds of inter­molecular hydrogen bonds, viz. O1—H1···Cl1ⁱⁱ and O2—H2···Cl1ⁱⁱ (Table 3), along the a axis, the hy­droxy O1 and O2 atoms acting as hydrogen-bond donors to chloride atom Cl1 from neighbouring molecules. The one-dimensional chain is generated in the same way as in the structure of [CuCl₂L₄] (L = uniconazole; Hu et al., 2014), whose one-dimensional chain is also generated by inter­molecular O—H···Cl hydrogen bonds between hy­droxy groups and coordinated chloride anions. The crystal packing of [CoCl₂L₄] is shown in Fig. 3.

According to anti­fungal screening data, the title cobalt(II) complex shows a higher inhibition effect than both uniconazole and CoCl₂ (Fig. 4 and Table 4). Uniconazole itself displays excellent anti­fungal activity against Botryosphaeria berengriana, (II); the inhibition rate of uniconazole is up to 99.70% at a concentration of 4.0 mg l^-1, so the anti­fungal activity increases a little when coordinating with CoCl₂, which reveals that uniconazole has a specificity for Botryosphaeria berengriana. Meanwhile, the inhibitory effects of complex (1) on Botryosphaeria ribis, (I), Wheat gibberellic, (III), and Grape anthracnose, (IV), are quite obvious; the inhibition rates have increased significantly, as shown in Fig. 4. Based on Table 4, cobalt(II) complex (1) has the best inhibitory activity on Grape anthracnose, (VI), whose toxicity was 11.54 times higher than that of uniconazole. As for the other two fungi, i.e. (I) and (III), the toxicity of [CoCl₂L₄] is enhanced by 9.77 and 4.10 times, respectively, compared to uniconazole. This increased activity of complex (1) can be explained on the basis of chelation theory. On chelation, the polarity of the metal cation is reduced to a great extent due to the overlap with the ligand orbital. Furthermore, this increases the delocalization of π-electrons over the whole chelate ring and enhances the lipophilicity of the complex (Chaudhary et al., 2003; Li, Xi, Yan, Guan et al., 2015), thus the anti­fungal effect of [CoCl₂L₄] is greatly improved compared to the conventional triazole fungicide uniconazole.

In this paper, a Co^II complex of uniconazole was synthesized and its structure confirmed. The results showed that it belongs to the triclinic system (P1 space group). The Co^II atom adopts a distorted o­cta­hedral geometry, where the equatorial plane is occupied by four triazole-ring N atoms from four equivalent uniconazole ligands and the axial positions are occupied by two chloride ligands. Adjacent [CoCl₂L₄] molecules are linked by O—H···Cl hydrogen bonds to form a one-dimensional chain. The anti­fungal activity of the complex was determined by the mycelial growth rate method. It is found that the anti­fungal activity for Botryosphaeria ribis, Wheat gibberellic and Grape anthracnose is greatly improved compared to the conventional triazole fungicide uniconazole.

Synthesis and crystallization

An ethanol solution (10 ml) of uniconazole (0.5836 g, 2 mmol) was added dropwise to an ethano­lic solution (5 ml) of CoCl₂.6H₂O (0.2379 g, 1 mmol). After stirring for 4 h at room temperature, the reaction liquid was filtered and red block-shaped crystals suitable for X-ray analysis were obtained by slow evaporation of the ethanol solution after 10 d (yield 80%, based on CoCl₂). Analysis calculated for C₆₀H₇₂Cl₆CoN₁₂O₄ (%): C 55.56, H 5.60, N 12.95; found: C 55.51, H 5.69, N 12.88. IR (KBr, ν/cm^-1): 3409 (w), 3166 (w), 2972 (s), 1645 (w), 1478 (w), 1401 (m), 1232 (m), 1068 (vs), 874 (m), 824 (w), 670 (m).

Refinement details

Crystal data, data collection and structure refinement details are summarized in Table 1. H atoms bonded to C atoms and hy­droxy O atoms were placed at calculated positions and refined using a riding-model approximation, with C—H = 0.96 Å and O—H = 0.82 Å, and with U_iso(H) = 1.5U_eq(C,O) for methyl and hy­droxy H atoms, and 1.2U_eq(C) for all other H atoms.

Computing details

Data collection: APEX2 (Bruker, 2008); cell refinement: SAINT (Bruker, 2008); data reduction: SAINT (Bruker, 2008); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL2014 (Sheldrick, 2015); molecular graphics: SHELXTL (Bruker, 2008); software used to prepare material for publication: SHELXTL (Bruker, 2008).

Figures

	Fig. 1. The crystal structure of [CoCl2L4], (1), showing the atom-numbering scheme. Displacement ellipsoids for non-H atoms are drawn at the 30% probability level. [Symmetry code: (i) -x, -y+1, -z+1.]
	Fig. 2. View of the hydrogen bonding (purple lines) of [CoCl2L4], (1), along the a axis. H atoms not involved in the hydrogen bonds have been omitted for clarity. [Symmetry code: (i) x+1, y, z.]
	Fig. 3. The crystal packing of [CoCl2L4], (1).
	Fig. 4. Inhibition rate of CoCl2, L and [CoCl2L4] with different concentrations.

Dichloridotetrakis[1-(4-chlorophenyl)-4,4-dimethyl-2-(1H-1,2,4-triazol-1-yl-κN⁴)pent-1-en-3-ol]cobalt(II)

Crystal data

[CoCl2(C15H18ClN3O)4]	Z = 1
Mr = 1296.92	F(000) = 677
Triclinic, P1	Dx = 1.279 Mg m^−3
a = 8.909 (2) Å	Mo Kα radiation, λ = 0.71073 Å
b = 13.332 (3) Å	Cell parameters from 991 reflections
c = 14.920 (3) Å	θ = 2.4–19.3°
α = 93.598 (4)°	µ = 0.55 mm^−1
β = 99.037 (5)°	T = 293 K
γ = 104.678 (4)°	Block, red
V = 1683.2 (6) Å^3	0.32 × 0.27 × 0.25 mm

Data collection

Bruker APEXII CCD diffractometer	6641 independent reflections
Radiation source: fine-focus sealed tube	3545 reflections with I > 2σ(I)
Detector resolution: 8.33 pixels mm^-1	Rint = 0.042
φ and ω scans	θmax = 26.3°, θmin = 2.0°
Absorption correction: multi-scan (SADABS; Krause et al., 2015)	h = −11→11
Tmin = 0.840, Tmax = 0.872	k = −16→16
9293 measured reflections	l = −9→18

Refinement

Refinement on F^2	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F^2 > 2σ(F^2)] = 0.058	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.146	H-atom parameters constrained
S = 0.95	w = 1/[σ^2(Fo^2) + (0.049P)^2] where P = (Fo^2 + 2Fc^2)/3
6641 reflections	(Δ/σ)max < 0.001
384 parameters	Δρmax = 0.27 e Å^−3
0 restraints	Δρmin = −0.27 e Å^−3

Special details

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.

Refinement. A bright-red crystal with dimensions of 0.27 mm × 0.32 mm × 0.25 mm was chosen for X-ray determination. Reflection data were collected at room temperature on a Bruker SMART APEX II area detector diffractometer equipped with a graphite-monochromatic using Mo Kα radiation (λ=0.71073 Å) at 296 (2) K with φ-ω scan mode. It was collected in 1.995° ≤ θ≤ 26.330° range, 9293 diffraction points, including 6641 for the independent diffraction points (R_int = 0.042), 3546 diffraction points is considered to be observed (I > 2σ(I)) and used in the succeeding refinements. Unit cell dimensions were obtained with least-squares refinements and semi-empirical absorption corrections were applied using the SADABS program (Krause et al., 2015). The structure was solved by direct methods (Sheldrick, 2008) and refined by full-matrix least squares techniques based on F². All non-hydrogen atoms were located by direct methods and subsequent difference Fourier syntheses. Crystallographic data and pertinent information are given in Table 1, selected bond lengths and angles in Table 2.

H atoms bonded to C and hydroxy O atoms were placed at calculated positions and refined using a riding model approximation.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Ų)

	x	y	z	Uiso*/Ueq
Co1	0.0000	0.5000	0.5000	0.0346 (2)
Cl1	−0.24050 (11)	0.51793 (8)	0.39443 (7)	0.0482 (3)
Cl2	0.72737 (18)	0.14441 (11)	−0.02690 (10)	0.0952 (5)
Cl3	1.07502 (19)	0.98266 (12)	0.14847 (12)	0.1113 (6)
O1	0.4456 (3)	0.5350 (2)	0.27237 (19)	0.0515 (7)
H1	0.5204	0.5183	0.3008	0.077*
O2	0.6198 (3)	0.6807 (2)	0.4927 (2)	0.0538 (8)
H2	0.6436	0.6397	0.4578	0.081*
N1	0.0543 (3)	0.4148 (2)	0.3900 (2)	0.0384 (8)
N2	0.1664 (4)	0.3687 (2)	0.2803 (2)	0.0403 (8)
N3	0.0143 (4)	0.3099 (3)	0.2595 (2)	0.0538 (10)
N4	0.1418 (4)	0.6412 (2)	0.4614 (2)	0.0420 (8)
N5	0.3428 (3)	0.7410 (2)	0.4133 (2)	0.0390 (8)
N6	0.2125 (4)	0.7679 (3)	0.3706 (2)	0.0537 (10)
C1	0.1878 (4)	0.4289 (3)	0.3582 (3)	0.0404 (10)
H1A	0.2834	0.4746	0.3865	0.048*
C2	−0.0467 (5)	0.3417 (3)	0.3272 (3)	0.0532 (12)
H2A	−0.1522	0.3155	0.3314	0.064*
C3	0.2803 (4)	0.3596 (3)	0.2235 (2)	0.0377 (9)
C4	0.3734 (5)	0.4604 (3)	0.1955 (3)	0.0426 (10)
H4	0.4581	0.4447	0.1672	0.051*
C5	0.2768 (5)	0.5111 (4)	0.1252 (3)	0.0544 (12)
C6	0.1605 (6)	0.5588 (4)	0.1672 (4)	0.0813 (16)
H6A	0.0757	0.5041	0.1797	0.122*
H6B	0.1190	0.6009	0.1251	0.122*
H6C	0.2142	0.6014	0.2229	0.122*
C7	0.3953 (7)	0.5981 (4)	0.0906 (4)	0.0891 (18)
H7A	0.4505	0.6499	0.1405	0.134*
H7B	0.3400	0.6296	0.0447	0.134*
H7C	0.4694	0.5692	0.0648	0.134*
C8	0.1895 (7)	0.4296 (4)	0.0455 (3)	0.0877 (18)
H8A	0.2622	0.3962	0.0234	0.132*
H8B	0.1431	0.4628	−0.0026	0.132*
H8C	0.1081	0.3784	0.0655	0.132*
C9	0.2842 (5)	0.2645 (3)	0.1960 (3)	0.0446 (10)
H9	0.2110	0.2095	0.2135	0.054*
C10	0.3950 (5)	0.2369 (3)	0.1397 (3)	0.0429 (10)
C11	0.5549 (5)	0.2699 (4)	0.1674 (3)	0.0597 (13)
H11	0.5952	0.3124	0.2222	0.072*
C12	0.6586 (6)	0.2427 (4)	0.1172 (3)	0.0641 (14)
H12	0.7670	0.2675	0.1368	0.077*
C13	0.5981 (6)	0.1782 (4)	0.0377 (3)	0.0576 (13)
C14	0.4385 (6)	0.1439 (4)	0.0066 (3)	0.0626 (13)
H14	0.3993	0.1022	−0.0487	0.075*
C15	0.3362 (5)	0.1718 (3)	0.0583 (3)	0.0586 (13)
H15	0.2278	0.1469	0.0386	0.070*
C16	0.2958 (5)	0.6663 (3)	0.4665 (3)	0.0423 (10)
H16	0.3635	0.6359	0.5025	0.051*
C17	0.0979 (5)	0.7063 (3)	0.4015 (3)	0.0533 (12)
H17	−0.0068	0.7068	0.3840	0.064*
C18	0.4949 (4)	0.7814 (3)	0.3886 (3)	0.0389 (10)
C19	0.6387 (4)	0.7793 (3)	0.4564 (3)	0.0426 (10)
H19	0.7259	0.7870	0.4224	0.051*
C20	0.6923 (5)	0.8673 (3)	0.5361 (3)	0.0493 (11)
C21	0.5751 (5)	0.8556 (4)	0.6021 (3)	0.0639 (13)
H21A	0.4768	0.8643	0.5714	0.096*
H21B	0.6169	0.9076	0.6536	0.096*
H21C	0.5580	0.7875	0.6227	0.096*
C22	0.7145 (6)	0.9735 (3)	0.4991 (3)	0.0764 (15)
H22A	0.7869	0.9797	0.4571	0.115*
H22B	0.7558	1.0279	0.5488	0.115*
H22C	0.6148	0.9796	0.4682	0.115*
C23	0.8524 (5)	0.8609 (4)	0.5876 (3)	0.0787 (16)
H23A	0.8407	0.7943	0.6107	0.118*
H23B	0.8898	0.9152	0.6374	0.118*
H23C	0.9268	0.8691	0.5467	0.118*
C24	0.4988 (5)	0.8210 (3)	0.3096 (3)	0.0528 (12)
H24	0.4030	0.8237	0.2759	0.063*
C25	0.6417 (5)	0.8614 (3)	0.2700 (3)	0.0476 (11)
C26	0.6825 (5)	0.9630 (4)	0.2485 (3)	0.0562 (12)
H26	0.6192	1.0065	0.2596	0.067*
C27	0.8155 (6)	1.0017 (4)	0.2107 (3)	0.0624 (13)
H27	0.8418	1.0700	0.1960	0.075*
C28	0.9073 (5)	0.9353 (4)	0.1956 (3)	0.0628 (14)
C29	0.8699 (6)	0.8344 (4)	0.2133 (3)	0.0682 (14)
H29	0.9324	0.7908	0.2007	0.082*
C30	0.7348 (5)	0.7974 (4)	0.2509 (3)	0.0608 (13)
H30	0.7073	0.7283	0.2634	0.073*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Co1	0.0252 (4)	0.0401 (5)	0.0399 (5)	0.0079 (3)	0.0118 (3)	0.0036 (4)
Cl1	0.0332 (6)	0.0592 (7)	0.0535 (7)	0.0163 (5)	0.0047 (5)	0.0059 (5)
Cl2	0.1106 (12)	0.0954 (11)	0.1051 (12)	0.0471 (10)	0.0665 (10)	0.0018 (9)
Cl3	0.1077 (12)	0.0839 (11)	0.1436 (15)	−0.0123 (9)	0.0967 (12)	−0.0079 (10)
O1	0.0422 (18)	0.0561 (19)	0.0513 (19)	0.0135 (14)	−0.0032 (14)	−0.0029 (15)
O2	0.060 (2)	0.0447 (18)	0.070 (2)	0.0259 (15)	0.0250 (17)	0.0181 (16)
N1	0.0268 (18)	0.050 (2)	0.037 (2)	0.0088 (16)	0.0067 (15)	0.0004 (16)
N2	0.0321 (19)	0.049 (2)	0.039 (2)	0.0089 (16)	0.0097 (15)	−0.0054 (16)
N3	0.032 (2)	0.066 (3)	0.057 (2)	0.0061 (18)	0.0093 (18)	−0.0142 (19)
N4	0.0318 (19)	0.046 (2)	0.048 (2)	0.0059 (16)	0.0143 (16)	0.0023 (17)
N5	0.0337 (19)	0.0369 (19)	0.049 (2)	0.0092 (15)	0.0139 (16)	0.0091 (16)
N6	0.039 (2)	0.056 (2)	0.074 (3)	0.0159 (18)	0.0171 (19)	0.030 (2)
C1	0.030 (2)	0.053 (3)	0.037 (2)	0.0085 (19)	0.0078 (18)	−0.005 (2)
C2	0.030 (2)	0.067 (3)	0.060 (3)	0.012 (2)	0.006 (2)	−0.008 (2)
C3	0.035 (2)	0.048 (3)	0.031 (2)	0.0120 (19)	0.0066 (18)	−0.0005 (19)
C4	0.038 (2)	0.050 (3)	0.041 (3)	0.015 (2)	0.0094 (19)	0.000 (2)
C5	0.063 (3)	0.056 (3)	0.043 (3)	0.017 (3)	0.006 (2)	0.008 (2)
C6	0.077 (4)	0.091 (4)	0.088 (4)	0.048 (3)	0.005 (3)	0.017 (3)
C7	0.121 (5)	0.073 (4)	0.080 (4)	0.025 (4)	0.029 (4)	0.039 (3)
C8	0.114 (5)	0.084 (4)	0.051 (3)	0.026 (4)	−0.027 (3)	0.006 (3)
C9	0.047 (3)	0.050 (3)	0.038 (3)	0.011 (2)	0.016 (2)	0.006 (2)
C10	0.057 (3)	0.041 (2)	0.036 (2)	0.021 (2)	0.016 (2)	0.0013 (19)
C11	0.061 (3)	0.080 (4)	0.042 (3)	0.032 (3)	0.005 (2)	−0.012 (2)
C12	0.054 (3)	0.086 (4)	0.061 (3)	0.036 (3)	0.009 (3)	0.002 (3)
C13	0.076 (4)	0.060 (3)	0.053 (3)	0.032 (3)	0.035 (3)	0.007 (2)
C14	0.077 (4)	0.058 (3)	0.049 (3)	0.009 (3)	0.023 (3)	−0.013 (2)
C15	0.061 (3)	0.057 (3)	0.054 (3)	0.003 (2)	0.024 (3)	−0.003 (2)
C16	0.040 (2)	0.040 (2)	0.047 (3)	0.0067 (19)	0.012 (2)	0.008 (2)
C17	0.036 (2)	0.051 (3)	0.082 (3)	0.016 (2)	0.021 (2)	0.020 (3)
C18	0.035 (2)	0.032 (2)	0.047 (3)	0.0013 (18)	0.013 (2)	0.0067 (19)
C19	0.036 (2)	0.045 (3)	0.053 (3)	0.0129 (19)	0.019 (2)	0.014 (2)
C20	0.049 (3)	0.048 (3)	0.047 (3)	0.007 (2)	0.006 (2)	0.006 (2)
C21	0.073 (3)	0.067 (3)	0.052 (3)	0.023 (3)	0.010 (3)	−0.004 (2)
C22	0.092 (4)	0.039 (3)	0.083 (4)	−0.001 (3)	0.005 (3)	0.002 (3)
C23	0.053 (3)	0.099 (4)	0.073 (4)	0.011 (3)	−0.006 (3)	0.011 (3)
C24	0.032 (2)	0.068 (3)	0.053 (3)	0.002 (2)	0.011 (2)	0.014 (2)
C25	0.047 (3)	0.053 (3)	0.041 (3)	0.004 (2)	0.016 (2)	0.010 (2)
C26	0.058 (3)	0.060 (3)	0.050 (3)	0.006 (2)	0.023 (2)	0.009 (2)
C27	0.072 (3)	0.052 (3)	0.058 (3)	−0.005 (3)	0.030 (3)	0.009 (2)
C28	0.066 (3)	0.053 (3)	0.066 (3)	−0.007 (3)	0.043 (3)	−0.001 (3)
C29	0.065 (3)	0.066 (3)	0.075 (4)	0.008 (3)	0.033 (3)	0.000 (3)
C30	0.064 (3)	0.053 (3)	0.065 (3)	0.006 (2)	0.024 (3)	0.014 (2)

Geometric parameters (Å, º)

Co1—N1^i	2.124 (3)	C9—C10	1.490 (5)
Co1—N1	2.124 (3)	C9—H9	0.9300
Co1—N4^i	2.152 (3)	C10—C11	1.367 (6)
Co1—N4	2.152 (3)	C10—C15	1.393 (6)
Co1—Cl1^i	2.5250 (11)	C11—C12	1.379 (5)
Co1—Cl1	2.5250 (11)	C11—H11	0.9300
Cl2—C13	1.737 (4)	C12—C13	1.368 (6)
Cl3—C28	1.742 (4)	C12—H12	0.9300
O1—C4	1.421 (5)	C13—C14	1.372 (6)
O1—H1	0.8200	C14—C15	1.387 (5)
O2—C19	1.433 (4)	C14—H14	0.9300
O2—H2	0.8200	C15—H15	0.9300
N1—C1	1.323 (4)	C16—H16	0.9300
N1—C2	1.347 (5)	C17—H17	0.9300
N2—C1	1.329 (4)	C18—C24	1.323 (5)
N2—N3	1.359 (4)	C18—C19	1.509 (5)
N2—C3	1.444 (4)	C19—C20	1.544 (6)
N3—C2	1.315 (5)	C19—H19	0.9800
N4—C16	1.316 (4)	C20—C22	1.529 (5)
N4—C17	1.366 (5)	C20—C21	1.531 (5)
N5—C16	1.338 (4)	C20—C23	1.536 (6)
N5—N6	1.374 (4)	C21—H21A	0.9600
N5—C18	1.441 (4)	C21—H21B	0.9600
N6—C17	1.304 (5)	C21—H21C	0.9600
C1—H1A	0.9300	C22—H22A	0.9600
C2—H2A	0.9300	C22—H22B	0.9600
C3—C9	1.318 (5)	C22—H22C	0.9600
C3—C4	1.511 (5)	C23—H23A	0.9600
C4—C5	1.548 (5)	C23—H23B	0.9600
C4—H4	0.9800	C23—H23C	0.9600
C5—C8	1.523 (6)	C24—C25	1.479 (5)
C5—C7	1.534 (6)	C24—H24	0.9300
C5—C6	1.536 (6)	C25—C30	1.379 (6)
C6—H6A	0.9600	C25—C26	1.383 (5)
C6—H6B	0.9600	C26—C27	1.387 (5)
C6—H6C	0.9600	C26—H26	0.9300
C7—H7A	0.9600	C27—C28	1.379 (6)
C7—H7B	0.9600	C27—H27	0.9300
C7—H7C	0.9600	C28—C29	1.356 (6)
C8—H8A	0.9600	C29—C30	1.397 (6)
C8—H8B	0.9600	C29—H29	0.9300
C8—H8C	0.9600	C30—H30	0.9300
N1^i—Co1—N1	180.0	C10—C11—C12	122.5 (4)
N1^i—Co1—N4^i	89.07 (12)	C10—C11—H11	118.7
N1—Co1—N4^i	90.93 (12)	C12—C11—H11	118.7
N1^i—Co1—N4	90.93 (12)	C13—C12—C11	118.3 (5)
N1—Co1—N4	89.07 (12)	C13—C12—H12	120.8
N4^i—Co1—N4	180.00 (12)	C11—C12—H12	120.8
N1^i—Co1—Cl1^i	88.82 (8)	C12—C13—C14	121.3 (4)
N1—Co1—Cl1^i	91.18 (8)	C12—C13—Cl2	118.8 (4)
N4^i—Co1—Cl1^i	90.96 (9)	C14—C13—Cl2	119.8 (4)
N4—Co1—Cl1^i	89.04 (9)	C13—C14—C15	119.4 (4)
N1^i—Co1—Cl1	91.18 (8)	C13—C14—H14	120.3
N1—Co1—Cl1	88.82 (8)	C15—C14—H14	120.3
N4^i—Co1—Cl1	89.04 (9)	C14—C15—C10	120.3 (4)
N4—Co1—Cl1	90.96 (9)	C14—C15—H15	119.9
Cl1^i—Co1—Cl1	180.0	C10—C15—H15	119.9
C4—O1—H1	109.5	N4—C16—N5	111.4 (3)
C19—O2—H2	109.5	N4—C16—H16	124.3
C1—N1—C2	102.4 (3)	N5—C16—H16	124.3
C1—N1—Co1	129.5 (3)	N6—C17—N4	115.5 (4)
C2—N1—Co1	127.5 (2)	N6—C17—H17	122.2
C1—N2—N3	109.6 (3)	N4—C17—H17	122.2
C1—N2—C3	128.7 (3)	C24—C18—N5	117.6 (4)
N3—N2—C3	121.7 (3)	C24—C18—C19	124.7 (3)
C2—N3—N2	102.1 (3)	N5—C18—C19	117.6 (3)
C16—N4—C17	101.9 (3)	O2—C19—C18	111.6 (3)
C16—N4—Co1	126.1 (3)	O2—C19—C20	109.0 (3)
C17—N4—Co1	128.8 (3)	C18—C19—C20	115.8 (3)
C16—N5—N6	108.6 (3)	O2—C19—H19	106.6
C16—N5—C18	130.0 (3)	C18—C19—H19	106.6
N6—N5—C18	120.8 (3)	C20—C19—H19	106.6
C17—N6—N5	102.5 (3)	C22—C20—C21	110.1 (4)
N1—C1—N2	110.5 (4)	C22—C20—C23	108.4 (4)
N1—C1—H1A	124.7	C21—C20—C23	109.1 (3)
N2—C1—H1A	124.7	C22—C20—C19	110.0 (3)
N3—C2—N1	115.4 (4)	C21—C20—C19	111.8 (3)
N3—C2—H2A	122.3	C23—C20—C19	107.3 (3)
N1—C2—H2A	122.3	C20—C21—H21A	109.5
C9—C3—N2	116.9 (3)	C20—C21—H21B	109.5
C9—C3—C4	126.8 (3)	H21A—C21—H21B	109.5
N2—C3—C4	116.0 (3)	C20—C21—H21C	109.5
O1—C4—C3	111.5 (3)	H21A—C21—H21C	109.5
O1—C4—C5	108.5 (3)	H21B—C21—H21C	109.5
C3—C4—C5	114.5 (3)	C20—C22—H22A	109.5
O1—C4—H4	107.3	C20—C22—H22B	109.5
C3—C4—H4	107.3	H22A—C22—H22B	109.5
C5—C4—H4	107.3	C20—C22—H22C	109.5
C8—C5—C7	109.0 (4)	H22A—C22—H22C	109.5
C8—C5—C6	110.4 (4)	H22B—C22—H22C	109.5
C7—C5—C6	108.7 (4)	C20—C23—H23A	109.5
C8—C5—C4	109.0 (4)	C20—C23—H23B	109.5
C7—C5—C4	106.9 (4)	H23A—C23—H23B	109.5
C6—C5—C4	112.6 (3)	C20—C23—H23C	109.5
C5—C6—H6A	109.5	H23A—C23—H23C	109.5
C5—C6—H6B	109.5	H23B—C23—H23C	109.5
H6A—C6—H6B	109.5	C18—C24—C25	125.9 (4)
C5—C6—H6C	109.5	C18—C24—H24	117.1
H6A—C6—H6C	109.5	C25—C24—H24	117.1
H6B—C6—H6C	109.5	C30—C25—C26	118.2 (4)
C5—C7—H7A	109.5	C30—C25—C24	120.6 (4)
C5—C7—H7B	109.5	C26—C25—C24	121.1 (4)
H7A—C7—H7B	109.5	C25—C26—C27	121.7 (4)
C5—C7—H7C	109.5	C25—C26—H26	119.1
H7A—C7—H7C	109.5	C27—C26—H26	119.1
H7B—C7—H7C	109.5	C28—C27—C26	117.7 (4)
C5—C8—H8A	109.5	C28—C27—H27	121.2
C5—C8—H8B	109.5	C26—C27—H27	121.2
H8A—C8—H8B	109.5	C29—C28—C27	122.8 (4)
C5—C8—H8C	109.5	C29—C28—Cl3	118.9 (4)
H8A—C8—H8C	109.5	C27—C28—Cl3	118.3 (4)
H8B—C8—H8C	109.5	C28—C29—C30	118.2 (4)
C3—C9—C10	126.1 (4)	C28—C29—H29	120.9
C3—C9—H9	117.0	C30—C29—H29	120.9
C10—C9—H9	117.0	C25—C30—C29	121.3 (4)
C11—C10—C15	118.1 (4)	C25—C30—H30	119.3
C11—C10—C9	121.9 (4)	C29—C30—H30	119.3
C15—C10—C9	119.9 (4)
C1—N2—N3—C2	1.4 (4)	C11—C10—C15—C14	−1.4 (6)
C3—N2—N3—C2	179.8 (3)	C9—C10—C15—C14	−178.6 (4)
C16—N5—N6—C17	−0.3 (4)	C17—N4—C16—N5	−0.3 (5)
C18—N5—N6—C17	171.7 (4)	Co1—N4—C16—N5	161.1 (2)
C2—N1—C1—N2	0.9 (4)	N6—N5—C16—N4	0.4 (5)
Co1—N1—C1—N2	−170.8 (2)	C18—N5—C16—N4	−170.6 (4)
N3—N2—C1—N1	−1.5 (5)	N5—N6—C17—N4	0.1 (5)
C3—N2—C1—N1	−179.8 (3)	C16—N4—C17—N6	0.1 (5)
N2—N3—C2—N1	−0.9 (5)	Co1—N4—C17—N6	−160.6 (3)
C1—N1—C2—N3	0.0 (5)	C16—N5—C18—C24	152.5 (4)
Co1—N1—C2—N3	171.9 (3)	N6—N5—C18—C24	−17.6 (5)
C1—N2—C3—C9	132.0 (4)	C16—N5—C18—C19	−29.8 (6)
N3—N2—C3—C9	−46.0 (5)	N6—N5—C18—C19	160.1 (3)
C1—N2—C3—C4	−52.7 (5)	C24—C18—C19—O2	−136.8 (4)
N3—N2—C3—C4	129.2 (4)	N5—C18—C19—O2	45.7 (4)
C9—C3—C4—O1	−132.8 (4)	C24—C18—C19—C20	97.8 (5)
N2—C3—C4—O1	52.6 (4)	N5—C18—C19—C20	−79.7 (4)
C9—C3—C4—C5	103.6 (5)	O2—C19—C20—C22	179.6 (3)
N2—C3—C4—C5	−71.1 (4)	C18—C19—C20—C22	−53.6 (5)
O1—C4—C5—C8	−176.0 (4)	O2—C19—C20—C21	−57.7 (4)
C3—C4—C5—C8	−50.8 (5)	C18—C19—C20—C21	69.1 (4)
O1—C4—C5—C7	66.2 (4)	O2—C19—C20—C23	61.8 (4)
C3—C4—C5—C7	−168.6 (4)	C18—C19—C20—C23	−171.4 (3)
O1—C4—C5—C6	−53.1 (5)	N5—C18—C24—C25	−176.8 (4)
C3—C4—C5—C6	72.1 (5)	C19—C18—C24—C25	5.7 (7)
N2—C3—C9—C10	−177.9 (4)	C18—C24—C25—C30	60.1 (7)
C4—C3—C9—C10	7.4 (7)	C18—C24—C25—C26	−122.0 (5)
C3—C9—C10—C11	58.2 (6)	C30—C25—C26—C27	−1.6 (7)
C3—C9—C10—C15	−124.7 (5)	C24—C25—C26—C27	−179.5 (4)
C15—C10—C11—C12	1.2 (7)	C25—C26—C27—C28	−0.4 (7)
C9—C10—C11—C12	178.2 (4)	C26—C27—C28—C29	2.3 (8)
C10—C11—C12—C13	−1.5 (7)	C26—C27—C28—Cl3	−179.9 (3)
C11—C12—C13—C14	2.1 (7)	C27—C28—C29—C30	−2.0 (8)
C11—C12—C13—Cl2	179.3 (3)	Cl3—C28—C29—C30	−179.9 (4)
C12—C13—C14—C15	−2.4 (7)	C26—C25—C30—C29	1.9 (7)
Cl2—C13—C14—C15	−179.6 (3)	C24—C25—C30—C29	179.8 (4)
C13—C14—C15—C10	2.0 (7)	C28—C29—C30—C25	−0.1 (8)

Symmetry code: (i) −x, −y+1, −z+1.

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
O1—H1···Cl1^ii	0.82	2.36	3.157 (3)	165
O2—H2···Cl1^ii	0.82	2.36	3.154 (3)	164

Symmetry code: (ii) x+1, y, z.