Crystal structure of bis­(aceto­phenone 4-benzoyl­thio­semicarbazonato-κ2N1,S)nickel(II)

Kadir, F.K.; Shamsuddin, M.; Rosli, M.M.

doi:10.1107/S2056989016006873

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ISSN: 2056-9890

Volume 72| Part 5| May 2016| Pages 760-763

doi:10.1107/S2056989016006873

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Crystal structure of bis(acetophenone 4-benzoylthiosemicarbazonato-κ²N¹,S)nickel(II)

Faraidoon Karim Kadir,^a,^b Mustaffa Shamsuddin ^a,^c ‡ and Mohd Mustaqim Rosli ^d ^*

^aDepartment of Chemistry, Faculty of Science, Universiti Teknologi Malaysia, 81310 UTM Johor Bahru, Johor, Malaysia, ^bDepartment of Chemistry, School of Science, Faculty of Science & Education, University of Sulaimani, Kurdistan Region, Iraq, ^cCentre for Sustainable Nanomaterials, Universiti Teknologi Malaysia, 81310 UTM Johor Bahru, Johor, Malaysia, and ^dX-ray Crystallography Unit, School of Physics, Universiti Sains Malaysia, 11800, USM, Penang, Malaysia
^*Correspondence e-mail: mustaqim@usm.my

Edited by T. J. Prior, University of Hull, England (Received 19 April 2016; accepted 23 April 2016; online 29 April 2016)

In the asymmetric unit of the title complex, [Ni(C₁₆H₁₄N₃OS)₂], the nickel ion is tetracoordinated in a distorted square-planar geometry by two independent molecules of the ligand which act as mononegative bidentate N,S-donors and form two five-membered chelate rings. The ligands are in trans (E) conformations with respect to the C=N bonds. The close approach of hydrogen atoms to the Ni²⁺ atom suggests anagostic interactions (Ni⋯H—C) are present. The crystal structure is built up by a network of two C—H⋯O interactions. One of the interactions forms inversion dimers and the other links the molecules into infinite chains parallel to [100]. In addition, a weak C—H⋯π interaction is also present.

Keywords: crystal structure; thiosemicarbazone; nickel(II); anagostic interactions; C—H⋯O interactions.

CCDC reference: 1476076

1. Chemical context

Thiosemicarbazones containing N and S donor atoms have been widely used in metal coordination chemistry due to their structural flexibility and versatility (Pelosi et al., 2010 ; Yousef et al., 2013 ; Jagadeesh et al., 2015 ). The chemistry of transition metal complexes of thiosemicarbazones has gained significant attention due to their potential medicinal applications (Pelosi et al., 2010; Li et al., 2012 ; Manikandan et al., 2014 ). The variable mode of binding of thiosemicarbazone towards nickel has encouraged us to explore its coordination chemistry further since nickel has the ability to take up different coordination environments. Nickel complexes are known to catalyse carbon–carbon cross-coupling and other reactions (Suganthy et al., 2013 ; Wang et al., 2014 ).

2. Structural commentary

The molecular structure of the title complex (I) with the numbering scheme is shown in Fig. 1. The nickel ion is tetra-coordinated in a square-planar geometry by two crystallographically independent molecules of the ligand which act as mononegative bidentate N,S-donors and form two five-membered chelate rings. The ligands are in trans (E) conformations with respect to the C7=N1 and C23=N4 bonds, as evidenced by the torsion angles N2—N1—C7—C6 = −171.0 (2) and N5—N4—C23—C22 = −171.8 (2)°, respectively. This is in close agreement with previously reported data (Sampath et al., 2013 , Suganthy et al., 2013). A remarkable tetrahedrally distorted square-planar coordination geometry is shown by the nickel metal ion, with the two ligands displaying a less common cis N,S-chelation mode (de Oliveira et al., 2014 ). The Ni—S and Ni—N bond lengths (Table 1) and the N1—Ni1—S2 and N4—Ni1-S1 bond angle of 159.86 (7) and 159.67 (7)°, respectively, confirm the distortion from a typical coordination geometry.

Table 1
Selected geometric parameters (Å, °)

Ni1—N4	1.922 (2)	S1—C9	1.728 (3)
Ni1—N1	1.928 (2)	S2—C25	1.735 (3)
Ni1—S2	2.1489 (10)	N1—C7	1.293 (3)
Ni1—S1	2.1518 (10)	N4—C23	1.294 (3)

N4—Ni1—N1	101.23 (10)	N4—Ni1—S1	159.67 (7)
N4—Ni1—S2	86.18 (7)	N1—Ni1—S1	85.99 (7)
N1—Ni1—S2	159.86 (7)	S2—Ni1—S1	93.44 (4)

Figure 1
The molecular structure of (I)

showing 50% probability displacement ellipsoids. H atoms are shown as spheres of arbitrary radius.

Upon chelation to the Ni^II ion, the ligands underwent deprotonation from the tautomeric thiolates and their negative charges are delocalized over atoms N1–N2–C9–S1 and N4–N5–C22–S2. Consequently, the bond lengths S1—C9 in one ligand and S2—C25 in the other ligand are 1.728 (3) and 1.735 (3) Å, respectively, which are consistent with single-bond character (Sankaraperumal et al., 2013 ). Furthermore, the Ni—N [1.922 (2) and 1.928 (2) Å] and Ni—S bond lengths [range 2.1489 (10) and 2.1518 (10) Å] are consistent with those in similar reported compounds. The S—C [1.728 and 1.735 (3)Å] and N—C [1.293 (3) and 1.294 (3) Å] bond lengths of the ligand are consistent with literature values (Sankaraperumal et al., 2013, de Oliveira et al., 2014).

Notably, two anagostic interactions in the trans-arrangement are observed in the title complex between the nickel(II) ion and the aromatic C—H groups (Fig. 2). The Ni1⋯H1A and Ni1⋯H17A distances are 2.616 and 2.527 Å, respectively, which are shorter than the van der Waals radii sum for Ni (1.63 Å; Bondi, 1964 ) and H (1.10 Å; Rowland & Taylor, 1996 ). In addition, the Ni1—H1A—C1 and Ni1—H17A—C17 bond angles are 109.6 and 112.7°, respectively. These observed values of contact distances and bond angles fall in the range for anagostic interactions reported by Brookhart et al. (2007 ). Similar observations have been reported recently by de Oliveira et al. (2014).

Figure 2
Two anagostic interactions (dashed lines) between the nickel(II) ion and the aromatic C—H groups.

3. Supramolecular features

The crystal structure of (I) contains a network of C—H⋯O interactions (Table 2). First the interaction C16—H16A⋯O1 links pairs of molecules to form inversion dimers enclosing centrosymmetric R₂²(10) ring motifs, as shown in Fig. 3. These dimers are further linked by C21—H21A⋯O2 interactions, resulting an infinite chains along [100] (Fig. 4). In addition, a C—H⋯π interaction is also present (Table 2).

Table 2
Hydrogen-bond geometry (Å, °)

Cg1 is the centroid of the C27–C32 ring.

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
C16—H16A⋯O1ⁱ	0.95	2.51	3.306 (5)	141
C21—H21A⋯O2ⁱⁱ	0.95	2.60	3.522 (4)	165
C19—H19A⋯Cg1ⁱⁱⁱ	0.95	2.86	3.400 (4)	117
Symmetry codes: (i) -x+1, -y, -z; (ii) x+1, y, z; (iii) -x+1, -y+1, -z.

Figure 3
Inversion dimers found in complex (I)

, formed by C—H⋯O hydrogen bonds (dashed lines; see Table 2

Figure 4
A view along the c axis of the crystal packing of complex (I)

, showing the infinite chain [100] formed by C—H⋯O interaction (dashed lines; see Table 2

). H atoms not involved in the hydrogen bonding have been omitted for clarity.

4. Synthesis and crystallization

The title complex was prepared by adding a solution of acetophenone-4-benzoyl-3-thiosemicarbazone (75 mg; 0.25 mmol) in dichloromethane (10 mL) dropwise to a stirred solution of nickel(II) nitrate hexahydrate (47.5 mg; 0.26 mmol) in 2-propanol (10 mL) in a small beaker. The resulting mixture solution was stirred continuously for 1 h at 318–323 K. The resultant green precipitate was separated by vacuum filtration, washed with 2-propanol and then with ether, and dried in a vacuum desiccator over dry silica gel. Single crystals suitable for X-ray analysis were obtained after slow evaporation of a dichloromethane solution saturated with 2-propanol. Yield; 52.5 mg, 65%. Melting point: 521–523 K.

5. Refinement

Crystal data, data collection and structure refinement details are summarized in Table 3. The H atoms attached to nitrogen were located in difference Fourier maps and freely refined. The remaining H atoms were positioned geometrically and refined using a riding model with C—H = 0.95–0.98 Å and U_iso(H) = 1.2U_eq(C) or 1.5U_eq(C-methyl). A rotating group model was applied to the methyl groups.

Table 3
Experimental details

Crystal data
Chemical formula	[Ni(C₁₆H₁₄N₃OS)₂]
M_r	651.43
Crystal system, space group	Monoclinic, P2₁/n
Temperature (K)	297
a, b, c (Å)	10.220 (3), 15.468 (5), 19.151 (6)
β (°)	92.150 (5)
V (Å³)	3025.1 (17)
Z	4
Radiation type	Mo Kα
μ (mm⁻¹)	0.82
Crystal size (mm)	0.19 × 0.18 × 0.09

Data collection
Diffractometer	Bruker APEX DUO CCD area-detector
Absorption correction	Multi-scan (SADABS; Bruker, 2009 )
No. of measured, independent and observed [I > 2σ(I)] reflections	43914, 5893, 4635
R_int	0.070
(sin θ/λ)_max (Å⁻¹)	0.617

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.048, 0.100, 1.05
No. of reflections	5893
No. of parameters	398
H-atom treatment	H atoms treated by a mixture of independent and constrained refinement
Δρ_max, Δρ_min (e Å⁻³)	0.46, −0.38
Computer programs: APEX2 and SAINT (Bruker, 2009), SHELXS97 (Sheldrick, 2008 ), SHELXL2014 (Sheldrick, 2015 ), PLATON (Spek, 2009 ) and publCIF (Westrip, 2010 ).

Supporting information

CCDC reference: 1476076

Crystal structure: contains datablock I. DOI: 10.1107/S2056989016006873/pj2029sup1.cif

Structure factors: contains datablock I. DOI: 10.1107/S2056989016006873/pj2029Isup2.hkl

checkCIF report

Chemical context top

Thiosemicarbazones containing N and S donor atoms have been widely used in metal coordination chemistry due to their structural flexibility and versatility (Pelosi et al. 2010; Yousef et al. 2013; Jagadeesh et al. 2015). The chemistry of transition metal complexes of thiosemicarbazones has gained significant attention due to their potential medicinal applications (Pelosi et al. 2010; Li et al. 2012; Manikandan et al. 2014). The variable mode of binding of thiosemicarbazone towards nickel has encouraged us to explore its coordination chemistry further since nickel has the ability to take up different coordination environments. Nickel complexes are known to catalyse carbon–carbon cross-coupling and other reactions (Suganthy et al. 2013; Wang et al. 2014).

Structural commentary top

The molecular structure of the title complex (I) with the numbering scheme is shown in Fig. 1. The nickel ion is tetra-coordinated in a square-planar geometry by two crystallographically independent molecules of the ligand which act as mononegative bidentate N,S-donors and form two five-membered chelate rings. The ligands are in trans (E) conformations with respect to the C7═N1 and C23═N4 bonds, as evidenced by the torsion angles N2—N1—C7—C6 = -171.0 (2) and N5—N4—C23—C22 = -171.8 (2)°, respectively. This is in close agreement with previously reported data (Sampath et al., 2013, Suganthy et al., 2013). A remarkable tetrahedrally distorted square-planar coordination geometry is shown by the nickel metal ion, with the two ligands displaying a less common cis N,S-chelation mode (de Oliveira et al., 2014). The Ni—S and Ni—N bond lengths (Table 1) and the N1—Ni1—S2 and N4—Ni1—S1 bond angle of 159.86 (7) and 159.67 (7)°, respectively, confirm the distortion from a typical coordination geometry.

Upon chelation to the Ni^II ion, the ligands underwent deprotonation from the tautomeric thiolates and their negative charges were delocalized over atoms N1–N2–C9–S1 and N4–N5–C22–S2. Consequently, the bond lengths S1—C9 in one ligand and S2—C25 in the other ligand are 1.728 (3) and 1.735 (3) Å, respectively, which are consistent with single-bond character (Sankaraperumal et al., 2013). Furthermore, the Ni—N [1.922 (2) and 1.928 (2) Å] and Ni—S bond lengths [range 2.1489 (10) and 2.1518 (10) Å] are consistent with those in similar reported compounds. The S—C [1.728 and 1.735 (3)Å] and N—C [1.293 (3) and 1.294 (3) Å] bond lengths of the ligand are consistent with literature values (Sankaraperumal et al., 2013, de Oliveira et al., 2014).

Notably, two anagostic interactions in the trans-arrangement are observed in the title complex between the nickel(II) ion and the aromatic C—H groups (Fig. 2). The Ni1···H1A and Ni1···H17A distances are 2.616 and 2.527 Å, respectively, which are shorter than the van der Waals radii sum for Ni (1.63 Å; Bondi 1964) and H (1.10 Å; Rowland & Taylor, 1996). In addition, the Ni1—H1A—C1 and Ni1—H17A—C17 bond angles are 109.6 and 112.7°, respectively. These observed values of contact distances and bond angles fall in the range for anagostic interactions reported by Brookhart et al. (2007). Similar observations have been reported recently by de Oliveira et al. (2014).

Supramolecular features top

The crystal structure of (I) contains a network of C—H···O interactions (Table 2). First the interaction C16—H16A···O1 links pairs of molecules to form inversion dimers enclosing centrosymmetric R²₂(10) ring motifs, as shown in Fig. 3. These dimers are further linked by C21—H21A···O2 interactions, resulting an infinite chains along [100] (Fig. 4). In addition, a C—H···π interaction is also present (Table 2).

Synthesis and crystallization top

Refinement top

Structure description top

The molecular structure of the title complex (I) with the numbering scheme is shown in Fig. 1. The nickel ion is tetra-coordinated in a square-planar geometry by two crystallographically independent molecules of the ligand which act as mononegative bidentate N,S-donors and form two five-membered chelate rings. The ligands are in trans (E) conformations with respect to the C7═N1 and C23═N4 bonds, as evidenced by the torsion angles N2—N1—C7—C6 = -171.0 (2) and N5—N4—C23—C22 = -171.8 (2)°, respectively. This is in close agreement with previously reported data (Sampath et al., 2013, Suganthy et al., 2013). A remarkable tetrahedrally distorted square-planar coordination geometry is shown by the nickel metal ion, with the two ligands displaying a less common cis N,S-chelation mode (de Oliveira et al., 2014). The Ni—S and Ni—N bond lengths (Table 1) and the N1—Ni1—S2 and N4—Ni1—S1 bond angle of 159.86 (7) and 159.67 (7)°, respectively, confirm the distortion from a typical coordination geometry.

Synthesis and crystallization top

Refinement details top

Computing details top

Data collection: APEX2 (Bruker, 2009); cell refinement: SAINT (Bruker, 2009); data reduction: SAINT (Bruker, 2009); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL2014 (Sheldrick, 2015); molecular graphics: SHELXL2014 (Sheldrick, 2015); software used to prepare material for publication: SHELXL2014 (Sheldrick, 2015), PLATON (Spek, 2009) and publCIF (Westrip, 2010).

Figures top

	Fig. 1. The molecular structure of (I) showing 50% probability displacement ellipsoids. H atoms are shown as spheres of arbitrary radius.
	Fig. 2. Two anagostic interactions (dashed lines) between the nickel(II) ion and the aromatic C—H groups.
	Fig. 3. Inversion dimers found in complex (I), formed by C—H···O hydrogen bonds (dashed lines; see Table 2).
	Fig. 4. A view along the c axis of the crystal packing of complex (I), showing the infinite chain [100] formed by C—H···O interaction (dashed lines; see Table 2). H atoms not involved in the hydrogen bonding have been omitted for clarity.

Bis(acetophenone 4-benzoylthiosemicarbazonato-κ²N¹,S)nickel(II) top

Crystal data top

[Ni(C₁₆H₁₄N₃OS)₂]	F(000) = 1352
M_r = 651.43	D_x = 1.430 Mg m⁻³
Monoclinic, P2₁/n	Mo Kα radiation, λ = 0.71073 Å
a = 10.220 (3) Å	Cell parameters from 9846 reflections
b = 15.468 (5) Å	θ = 2.2–30.1°
c = 19.151 (6) Å	µ = 0.82 mm⁻¹
β = 92.150 (5)°	T = 297 K
V = 3025.1 (17) Å³	Block, dark green
Z = 4	0.19 × 0.18 × 0.09 mm

Data collection top

Bruker APEX DUO CCD area-detector diffractometer	4635 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tube	R_int = 0.070
φ and ω scans	θ_max = 26.0°, θ_min = 1.7°
Absorption correction: multi-scan (SADABS; Bruker, 2009)	h = −12→12
	k = −19→19
43914 measured reflections	l = −23→23
5893 independent reflections

Refinement top

Refinement on F²	0 restraints
Least-squares matrix: full	Hydrogen site location: mixed
R[F² > 2σ(F²)] = 0.048	H atoms treated by a mixture of independent and constrained refinement
wR(F²) = 0.100	w = 1/[σ²(F_o²) + (0.0315P)² + 3.0091P] where P = (F_o² + 2F_c²)/3
S = 1.05	(Δ/σ)_max < 0.001
5893 reflections	Δρ_max = 0.46 e Å⁻³
398 parameters	Δρ_min = −0.38 e Å⁻³

Crystal data top

[Ni(C₁₆H₁₄N₃OS)₂]	V = 3025.1 (17) Å³
M_r = 651.43	Z = 4
Monoclinic, P2₁/n	Mo Kα radiation
a = 10.220 (3) Å	µ = 0.82 mm⁻¹
b = 15.468 (5) Å	T = 297 K
c = 19.151 (6) Å	0.19 × 0.18 × 0.09 mm
β = 92.150 (5)°

Data collection top

Bruker APEX DUO CCD area-detector diffractometer	5893 independent reflections
Absorption correction: multi-scan (SADABS; Bruker, 2009)	4635 reflections with I > 2σ(I)
	R_int = 0.070
43914 measured reflections

Refinement top

R[F² > 2σ(F²)] = 0.048	0 restraints
wR(F²) = 0.100	H atoms treated by a mixture of independent and constrained refinement
S = 1.05	Δρ_max = 0.46 e Å⁻³
5893 reflections	Δρ_min = −0.38 e Å⁻³
398 parameters

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
Ni1	0.38656 (3)	0.38363 (2)	0.14831 (2)	0.03092 (11)
S1	0.29568 (8)	0.25816 (5)	0.14900 (5)	0.0468 (2)
S2	0.20856 (7)	0.44818 (5)	0.11538 (4)	0.03977 (19)
O1	0.4015 (4)	0.09249 (17)	0.07102 (13)	0.0989 (12)
O2	0.0116 (2)	0.58787 (16)	0.14021 (16)	0.0740 (8)
N1	0.5206 (2)	0.33342 (14)	0.20917 (11)	0.0313 (5)
N2	0.5355 (2)	0.24301 (14)	0.20848 (12)	0.0359 (5)
N3	0.4341 (3)	0.11462 (16)	0.18572 (14)	0.0417 (6)
N4	0.4758 (2)	0.48357 (14)	0.11409 (11)	0.0323 (5)
N5	0.4058 (2)	0.56192 (15)	0.10985 (12)	0.0363 (6)
N6	0.2077 (3)	0.62374 (18)	0.09826 (14)	0.0437 (7)
C1	0.4607 (3)	0.4993 (2)	0.27376 (15)	0.0421 (7)
H1A	0.3864	0.4626	0.2691	0.051*
C2	0.4439 (4)	0.5856 (2)	0.28904 (18)	0.0600 (10)
H2A	0.3585	0.6081	0.2949	0.072*
C3	0.5504 (5)	0.6388 (2)	0.2958 (2)	0.0709 (12)
H3A	0.5388	0.6983	0.3061	0.085*
C4	0.6732 (5)	0.6070 (2)	0.2879 (2)	0.0708 (12)
H4A	0.7468	0.6444	0.2924	0.085*
C5	0.6910 (3)	0.5205 (2)	0.27322 (18)	0.0532 (9)
H5A	0.7770	0.4984	0.2687	0.064*
C6	0.5840 (3)	0.46575 (18)	0.26511 (14)	0.0351 (6)
C7	0.6017 (3)	0.37289 (18)	0.25164 (14)	0.0327 (6)
C8	0.7109 (3)	0.3267 (2)	0.28965 (17)	0.0496 (8)
H8A	0.7528	0.3657	0.3241	0.074*
H8B	0.7755	0.3079	0.2563	0.074*
H8C	0.6762	0.2761	0.3136	0.074*
C9	0.4336 (3)	0.20575 (18)	0.18243 (14)	0.0362 (7)
C10	0.4225 (4)	0.0628 (2)	0.12850 (16)	0.0483 (8)
C11	0.4392 (3)	−0.03163 (18)	0.14117 (15)	0.0383 (7)
C12	0.4104 (3)	−0.07032 (19)	0.20340 (16)	0.0422 (7)
H12A	0.3823	−0.0362	0.2412	0.051*
C13	0.4223 (3)	−0.1588 (2)	0.21092 (19)	0.0529 (9)
H13A	0.4006	−0.1854	0.2537	0.063*
C14	0.4651 (3)	−0.2085 (2)	0.1574 (2)	0.0537 (9)
H14A	0.4727	−0.2694	0.1629	0.064*
C15	0.4970 (4)	−0.1705 (2)	0.09600 (18)	0.0558 (9)
H15A	0.5291	−0.2047	0.0591	0.067*
C16	0.4826 (4)	−0.0828 (2)	0.08766 (17)	0.0568 (9)
H16A	0.5028	−0.0569	0.0444	0.068*
C17	0.6155 (3)	0.3332 (2)	0.06147 (14)	0.0391 (7)
H17A	0.5243	0.3319	0.0498	0.047*
C18	0.6894 (3)	0.2592 (2)	0.05372 (15)	0.0445 (8)
H18A	0.6488	0.2073	0.0375	0.053*
C19	0.8210 (3)	0.2609 (2)	0.06944 (16)	0.0495 (8)
H19A	0.8720	0.2101	0.0643	0.059*
C20	0.8790 (3)	0.3359 (2)	0.09259 (17)	0.0522 (9)
H20A	0.9706	0.3369	0.1032	0.063*
C21	0.8063 (3)	0.4102 (2)	0.10076 (16)	0.0451 (8)
H21A	0.8481	0.4619	0.1164	0.054*
C22	0.6723 (3)	0.40955 (19)	0.08613 (14)	0.0344 (6)
C23	0.5946 (3)	0.48889 (18)	0.09338 (14)	0.0344 (6)
C24	0.6553 (3)	0.5734 (2)	0.07503 (18)	0.0488 (8)
H24A	0.6976	0.5680	0.0301	0.073*
H24B	0.7208	0.5895	0.1114	0.073*
H24C	0.5874	0.6180	0.0715	0.073*
C25	0.2822 (3)	0.54878 (18)	0.10913 (14)	0.0337 (6)
C26	0.0801 (3)	0.6392 (2)	0.11104 (17)	0.0443 (8)
C27	0.0329 (3)	0.7260 (2)	0.08622 (15)	0.0391 (7)
C28	0.1022 (3)	0.8009 (2)	0.10018 (17)	0.0482 (8)
H28A	0.1824	0.7984	0.1269	0.058*
C29	0.0558 (4)	0.8797 (2)	0.07568 (18)	0.0590 (9)
H29A	0.1040	0.9310	0.0859	0.071*
C30	−0.0587 (4)	0.8839 (3)	0.0369 (2)	0.0629 (10)
H30A	−0.0902	0.9381	0.0199	0.075*
C31	−0.1284 (4)	0.8099 (3)	0.02259 (18)	0.0610 (10)
H31A	−0.2082	0.8130	−0.0044	0.073*
C32	−0.0837 (3)	0.7306 (2)	0.04694 (17)	0.0501 (8)
H32A	−0.1326	0.6796	0.0368	0.060*
H1N3	0.469 (3)	0.094 (2)	0.2191 (16)	0.040 (9)*
H1N6	0.247 (3)	0.662 (2)	0.0807 (18)	0.057 (11)*

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
Ni1	0.0308 (2)	0.02381 (19)	0.0382 (2)	−0.00201 (15)	0.00162 (14)	0.00350 (15)
S1	0.0369 (4)	0.0279 (4)	0.0755 (6)	−0.0047 (3)	−0.0012 (4)	0.0022 (4)
S2	0.0331 (4)	0.0334 (4)	0.0527 (4)	−0.0017 (3)	0.0002 (3)	0.0065 (3)
O1	0.209 (4)	0.0493 (16)	0.0385 (13)	0.043 (2)	0.0135 (18)	0.0059 (12)
O2	0.0527 (16)	0.0495 (15)	0.122 (2)	0.0062 (12)	0.0323 (16)	0.0261 (15)
N1	0.0352 (13)	0.0235 (12)	0.0354 (12)	0.0022 (10)	0.0030 (10)	0.0011 (9)
N2	0.0444 (15)	0.0225 (13)	0.0408 (13)	0.0024 (11)	0.0020 (11)	0.0013 (10)
N3	0.0586 (18)	0.0232 (13)	0.0430 (15)	0.0007 (12)	−0.0011 (13)	0.0044 (12)
N4	0.0314 (13)	0.0277 (13)	0.0378 (12)	0.0001 (10)	0.0020 (10)	0.0028 (10)
N5	0.0344 (14)	0.0286 (13)	0.0462 (14)	0.0024 (11)	0.0049 (11)	0.0073 (10)
N6	0.0382 (16)	0.0345 (15)	0.0592 (17)	0.0043 (13)	0.0111 (13)	0.0155 (13)
C1	0.0466 (19)	0.0400 (18)	0.0397 (16)	0.0040 (15)	0.0008 (14)	−0.0050 (13)
C2	0.076 (3)	0.048 (2)	0.056 (2)	0.021 (2)	−0.0094 (19)	−0.0111 (17)
C3	0.108 (4)	0.032 (2)	0.070 (2)	0.009 (2)	−0.031 (2)	−0.0107 (17)
C4	0.086 (3)	0.040 (2)	0.083 (3)	−0.020 (2)	−0.026 (2)	0.0003 (19)
C5	0.050 (2)	0.045 (2)	0.064 (2)	−0.0099 (16)	−0.0082 (16)	−0.0020 (16)
C6	0.0408 (17)	0.0321 (16)	0.0321 (14)	−0.0011 (13)	−0.0021 (12)	−0.0003 (12)
C7	0.0335 (15)	0.0321 (16)	0.0326 (14)	0.0006 (13)	0.0046 (12)	0.0008 (12)
C8	0.0474 (19)	0.045 (2)	0.0550 (19)	0.0114 (16)	−0.0114 (15)	−0.0040 (15)
C9	0.0460 (18)	0.0242 (15)	0.0389 (15)	0.0008 (13)	0.0093 (13)	0.0014 (12)
C10	0.072 (2)	0.0336 (18)	0.0398 (17)	0.0091 (16)	0.0133 (16)	0.0018 (14)
C11	0.0477 (18)	0.0260 (15)	0.0411 (16)	0.0049 (13)	0.0005 (13)	−0.0012 (12)
C12	0.0474 (19)	0.0321 (17)	0.0477 (17)	0.0006 (14)	0.0103 (14)	0.0012 (13)
C13	0.052 (2)	0.0371 (19)	0.070 (2)	−0.0007 (16)	0.0124 (17)	0.0146 (17)
C14	0.051 (2)	0.0260 (17)	0.083 (3)	−0.0021 (15)	−0.0117 (18)	−0.0024 (17)
C15	0.072 (2)	0.040 (2)	0.055 (2)	0.0129 (17)	−0.0132 (18)	−0.0175 (16)
C16	0.089 (3)	0.043 (2)	0.0389 (17)	0.0126 (19)	−0.0001 (17)	−0.0044 (15)
C17	0.0364 (16)	0.0485 (19)	0.0327 (14)	−0.0001 (14)	0.0056 (12)	−0.0008 (13)
C18	0.054 (2)	0.0422 (19)	0.0374 (16)	0.0025 (16)	0.0067 (14)	−0.0032 (13)
C19	0.054 (2)	0.051 (2)	0.0435 (17)	0.0151 (17)	0.0088 (15)	0.0042 (15)
C20	0.0327 (17)	0.067 (2)	0.057 (2)	0.0062 (17)	0.0055 (15)	0.0032 (18)
C21	0.0358 (17)	0.049 (2)	0.0511 (18)	−0.0033 (15)	0.0059 (14)	0.0011 (15)
C22	0.0340 (16)	0.0389 (17)	0.0309 (14)	−0.0002 (13)	0.0074 (12)	0.0039 (12)
C23	0.0341 (16)	0.0353 (16)	0.0340 (14)	−0.0030 (13)	0.0026 (12)	0.0041 (12)
C24	0.0421 (19)	0.0419 (19)	0.063 (2)	−0.0059 (15)	0.0133 (16)	0.0101 (16)
C25	0.0370 (17)	0.0304 (16)	0.0341 (14)	0.0039 (13)	0.0068 (12)	0.0065 (12)
C26	0.0406 (18)	0.0385 (18)	0.0542 (19)	0.0018 (14)	0.0093 (15)	0.0042 (14)
C27	0.0345 (16)	0.0404 (18)	0.0431 (16)	0.0049 (14)	0.0101 (13)	0.0025 (13)
C28	0.049 (2)	0.044 (2)	0.0521 (18)	0.0039 (16)	−0.0020 (15)	−0.0012 (15)
C29	0.077 (3)	0.038 (2)	0.062 (2)	0.0052 (19)	0.006 (2)	−0.0033 (16)
C30	0.075 (3)	0.050 (2)	0.064 (2)	0.022 (2)	0.009 (2)	0.0128 (18)
C31	0.047 (2)	0.079 (3)	0.057 (2)	0.018 (2)	0.0037 (17)	0.0150 (19)
C32	0.0397 (18)	0.053 (2)	0.058 (2)	−0.0003 (16)	0.0060 (15)	0.0043 (16)

Geometric parameters (Å, º) top

Ni1—N4	1.922 (2)	C11—C16	1.381 (4)
Ni1—N1	1.928 (2)	C12—C13	1.381 (4)
Ni1—S2	2.1489 (10)	C12—H12A	0.9500
Ni1—S1	2.1518 (10)	C13—C14	1.366 (5)
S1—C9	1.728 (3)	C13—H13A	0.9500
S2—C25	1.735 (3)	C14—C15	1.365 (5)
O1—C10	1.204 (4)	C14—H14A	0.9500
O2—C26	1.210 (4)	C15—C16	1.374 (5)
N1—C7	1.293 (3)	C15—H15A	0.9500
N1—N2	1.407 (3)	C16—H16A	0.9500
N2—C9	1.275 (4)	C17—C18	1.383 (4)
N3—C10	1.359 (4)	C17—C22	1.391 (4)
N3—C9	1.411 (4)	C17—H17A	0.9500
N3—H1N3	0.78 (3)	C18—C19	1.367 (4)
N4—C23	1.294 (3)	C18—H18A	0.9500
N4—N5	1.408 (3)	C19—C20	1.369 (5)
N5—C25	1.279 (4)	C19—H19A	0.9500
N6—C26	1.356 (4)	C20—C21	1.381 (5)
N6—C25	1.399 (4)	C20—H20A	0.9500
N6—H1N6	0.80 (3)	C21—C22	1.387 (4)
C1—C2	1.379 (5)	C21—H21A	0.9500
C1—C6	1.379 (4)	C22—C23	1.471 (4)
C1—H1A	0.9500	C23—C24	1.494 (4)
C2—C3	1.366 (6)	C24—H24A	0.9800
C2—H2A	0.9500	C24—H24B	0.9800
C3—C4	1.361 (6)	C24—H24C	0.9800
C3—H3A	0.9500	C26—C27	1.497 (4)
C4—C5	1.380 (5)	C27—C28	1.380 (4)
C4—H4A	0.9500	C27—C32	1.387 (4)
C5—C6	1.388 (4)	C28—C29	1.383 (5)
C5—H5A	0.9500	C28—H28A	0.9500
C6—C7	1.472 (4)	C29—C30	1.364 (5)
C7—C8	1.491 (4)	C29—H29A	0.9500
C8—H8A	0.9800	C30—C31	1.371 (5)
C8—H8B	0.9800	C30—H30A	0.9500
C8—H8C	0.9800	C31—C32	1.383 (5)
C10—C11	1.490 (4)	C31—H31A	0.9500
C11—C12	1.375 (4)	C32—H32A	0.9500

N4—Ni1—N1	101.23 (10)	C14—C13—H13A	119.7
N4—Ni1—S2	86.18 (7)	C12—C13—H13A	119.7
N1—Ni1—S2	159.86 (7)	C15—C14—C13	119.9 (3)
N4—Ni1—S1	159.67 (7)	C15—C14—H14A	120.1
N1—Ni1—S1	85.99 (7)	C13—C14—H14A	120.1
S2—Ni1—S1	93.44 (4)	C14—C15—C16	119.8 (3)
C9—S1—Ni1	94.53 (10)	C14—C15—H15A	120.1
C25—S2—Ni1	94.14 (10)	C16—C15—H15A	120.1
C7—N1—N2	114.1 (2)	C15—C16—C11	121.1 (3)
C7—N1—Ni1	127.91 (19)	C15—C16—H16A	119.5
N2—N1—Ni1	118.01 (17)	C11—C16—H16A	119.5
C9—N2—N1	111.4 (2)	C18—C17—C22	121.1 (3)
C10—N3—C9	123.6 (3)	C18—C17—H17A	119.4
C10—N3—H1N3	116 (2)	C22—C17—H17A	119.4
C9—N3—H1N3	116 (2)	C19—C18—C17	119.8 (3)
C23—N4—N5	114.1 (2)	C19—C18—H18A	120.1
C23—N4—Ni1	128.18 (19)	C17—C18—H18A	120.1
N5—N4—Ni1	117.74 (17)	C18—C19—C20	119.9 (3)
C25—N5—N4	111.3 (2)	C18—C19—H19A	120.1
C26—N6—C25	129.9 (3)	C20—C19—H19A	120.1
C26—N6—H1N6	117 (3)	C19—C20—C21	120.9 (3)
C25—N6—H1N6	113 (3)	C19—C20—H20A	119.5
C2—C1—C6	120.8 (3)	C21—C20—H20A	119.5
C2—C1—H1A	119.6	C20—C21—C22	120.2 (3)
C6—C1—H1A	119.6	C20—C21—H21A	119.9
C3—C2—C1	119.8 (4)	C22—C21—H21A	119.9
C3—C2—H2A	120.1	C21—C22—C17	118.1 (3)
C1—C2—H2A	120.1	C21—C22—C23	120.5 (3)
C4—C3—C2	120.5 (3)	C17—C22—C23	121.4 (3)
C4—C3—H3A	119.8	N4—C23—C22	119.5 (2)
C2—C3—H3A	119.8	N4—C23—C24	122.0 (3)
C3—C4—C5	120.1 (4)	C22—C23—C24	118.5 (2)
C3—C4—H4A	119.9	C23—C24—H24A	109.5
C5—C4—H4A	119.9	C23—C24—H24B	109.5
C4—C5—C6	120.3 (4)	H24A—C24—H24B	109.5
C4—C5—H5A	119.8	C23—C24—H24C	109.5
C6—C5—H5A	119.8	H24A—C24—H24C	109.5
C1—C6—C5	118.5 (3)	H24B—C24—H24C	109.5
C1—C6—C7	120.5 (3)	N5—C25—N6	113.7 (3)
C5—C6—C7	120.9 (3)	N5—C25—S2	124.9 (2)
N1—C7—C6	119.4 (2)	N6—C25—S2	121.2 (2)
N1—C7—C8	122.1 (3)	O2—C26—N6	123.0 (3)
C6—C7—C8	118.5 (2)	O2—C26—C27	123.4 (3)
C7—C8—H8A	109.5	N6—C26—C27	113.7 (3)
C7—C8—H8B	109.5	C28—C27—C32	119.1 (3)
H8A—C8—H8B	109.5	C28—C27—C26	122.3 (3)
C7—C8—H8C	109.5	C32—C27—C26	118.6 (3)
H8A—C8—H8C	109.5	C27—C28—C29	120.5 (3)
H8B—C8—H8C	109.5	C27—C28—H28A	119.7
N2—C9—N3	115.7 (3)	C29—C28—H28A	119.7
N2—C9—S1	125.1 (2)	C30—C29—C28	120.2 (4)
N3—C9—S1	119.1 (2)	C30—C29—H29A	119.9
O1—C10—N3	121.3 (3)	C28—C29—H29A	119.9
O1—C10—C11	122.5 (3)	C29—C30—C31	119.8 (3)
N3—C10—C11	116.2 (3)	C29—C30—H30A	120.1
C12—C11—C16	118.6 (3)	C31—C30—H30A	120.1
C12—C11—C10	122.7 (3)	C30—C31—C32	120.7 (3)
C16—C11—C10	118.6 (3)	C30—C31—H31A	119.7
C11—C12—C13	120.0 (3)	C32—C31—H31A	119.7
C11—C12—H12A	120.0	C31—C32—C27	119.7 (3)
C13—C12—H12A	120.0	C31—C32—H32A	120.2
C14—C13—C12	120.6 (3)	C27—C32—H32A	120.2

C7—N1—N2—C9	161.4 (2)	C12—C11—C16—C15	0.0 (5)
Ni1—N1—N2—C9	−19.0 (3)	C10—C11—C16—C15	−178.6 (3)
C23—N4—N5—C25	159.4 (2)	C22—C17—C18—C19	−1.0 (4)
Ni1—N4—N5—C25	−20.2 (3)	C17—C18—C19—C20	−0.2 (5)
C6—C1—C2—C3	0.0 (5)	C18—C19—C20—C21	0.4 (5)
C1—C2—C3—C4	−0.3 (6)	C19—C20—C21—C22	0.6 (5)
C2—C3—C4—C5	−0.3 (6)	C20—C21—C22—C17	−1.7 (4)
C3—C4—C5—C6	1.2 (6)	C20—C21—C22—C23	−178.8 (3)
C2—C1—C6—C5	1.0 (4)	C18—C17—C22—C21	1.9 (4)
C2—C1—C6—C7	177.5 (3)	C18—C17—C22—C23	179.0 (2)
C4—C5—C6—C1	−1.6 (5)	N5—N4—C23—C22	−171.8 (2)
C4—C5—C6—C7	−178.1 (3)	Ni1—N4—C23—C22	7.8 (4)
N2—N1—C7—C6	−171.0 (2)	N5—N4—C23—C24	7.0 (4)
Ni1—N1—C7—C6	9.4 (4)	Ni1—N4—C23—C24	−173.5 (2)
N2—N1—C7—C8	6.9 (4)	C21—C22—C23—N4	−145.6 (3)
Ni1—N1—C7—C8	−172.7 (2)	C17—C22—C23—N4	37.4 (4)
C1—C6—C7—N1	41.4 (4)	C21—C22—C23—C24	35.6 (4)
C5—C6—C7—N1	−142.2 (3)	C17—C22—C23—C24	−141.4 (3)
C1—C6—C7—C8	−136.6 (3)	N4—N5—C25—N6	−174.2 (2)
C5—C6—C7—C8	39.8 (4)	N4—N5—C25—S2	1.9 (3)
N1—N2—C9—N3	−174.0 (2)	C26—N6—C25—N5	−161.8 (3)
N1—N2—C9—S1	2.2 (3)	C26—N6—C25—S2	21.9 (5)
C10—N3—C9—N2	−121.1 (3)	Ni1—S2—C25—N5	13.3 (3)
C10—N3—C9—S1	62.5 (4)	Ni1—S2—C25—N6	−170.8 (2)
Ni1—S1—C9—N2	12.1 (3)	C25—N6—C26—O2	5.6 (6)
Ni1—S1—C9—N3	−171.8 (2)	C25—N6—C26—C27	−174.9 (3)
C9—N3—C10—O1	−5.5 (6)	O2—C26—C27—C28	131.8 (4)
C9—N3—C10—C11	173.7 (3)	N6—C26—C27—C28	−47.7 (4)
O1—C10—C11—C12	−152.7 (4)	O2—C26—C27—C32	−49.2 (5)
N3—C10—C11—C12	28.1 (5)	N6—C26—C27—C32	131.3 (3)
O1—C10—C11—C16	25.8 (6)	C32—C27—C28—C29	0.3 (5)
N3—C10—C11—C16	−153.4 (3)	C26—C27—C28—C29	179.3 (3)
C16—C11—C12—C13	−1.4 (5)	C27—C28—C29—C30	−0.4 (5)
C10—C11—C12—C13	177.1 (3)	C28—C29—C30—C31	0.3 (6)
C11—C12—C13—C14	1.3 (5)	C29—C30—C31—C32	−0.1 (6)
C12—C13—C14—C15	0.3 (5)	C30—C31—C32—C27	−0.1 (5)
C13—C14—C15—C16	−1.7 (5)	C28—C27—C32—C31	0.0 (5)
C14—C15—C16—C11	1.6 (6)	C26—C27—C32—C31	−179.1 (3)

Hydrogen-bond geometry (Å, º) top

Cg1 is the centroid of the C27–C32 ring.

D—H···A	D—H	H···A	D···A	D—H···A
C16—H16A···O1ⁱ	0.95	2.51	3.306 (5)	141
C21—H21A···O2ⁱⁱ	0.95	2.60	3.522 (4)	165
C19—H19A···Cg1ⁱⁱⁱ	0.95	2.86	3.400 (4)	117

Symmetry codes: (i) −x+1, −y, −z; (ii) x+1, y, z; (iii) −x+1, −y+1, −z.

Selected geometric parameters (Å, º) top

Ni1—N4	1.922 (2)	S1—C9	1.728 (3)
Ni1—N1	1.928 (2)	S2—C25	1.735 (3)
Ni1—S2	2.1489 (10)	N1—C7	1.293 (3)
Ni1—S1	2.1518 (10)	N4—C23	1.294 (3)

N4—Ni1—N1	101.23 (10)	N4—Ni1—S1	159.67 (7)
N4—Ni1—S2	86.18 (7)	N1—Ni1—S1	85.99 (7)
N1—Ni1—S2	159.86 (7)	S2—Ni1—S1	93.44 (4)

Hydrogen-bond geometry (Å, º) top

Cg1 is the centroid of the C27–C32 ring.

D—H···A	D—H	H···A	D···A	D—H···A
C16—H16A···O1ⁱ	0.9500	2.5100	3.306 (5)	141.00
C21—H21A···O2ⁱⁱ	0.9500	2.6000	3.522 (4)	165.00
C19—H19A···Cg1ⁱⁱⁱ	0.9500	2.8600	3.400 (4)	117.00

Symmetry codes: (i) −x+1, −y, −z; (ii) x+1, y, z; (iii) −x+1, −y+1, −z.

Experimental details

Crystal data
Chemical formula	[Ni(C₁₆H₁₄N₃OS)₂]
M_r	651.43
Crystal system, space group	Monoclinic, P2₁/n
Temperature (K)	297
a, b, c (Å)	10.220 (3), 15.468 (5), 19.151 (6)
β (°)	92.150 (5)
V (Å³)	3025.1 (17)
Z	4
Radiation type	Mo Kα
µ (mm⁻¹)	0.82
Crystal size (mm)	0.19 × 0.18 × 0.09

Data collection
Diffractometer	Bruker APEX DUO CCD area-detector
Absorption correction	Multi-scan (SADABS; Bruker, 2009)
No. of measured, independent and observed [I > 2σ(I)] reflections	43914, 5893, 4635
R_int	0.070
(sin θ/λ)_max (Å⁻¹)	0.617

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.048, 0.100, 1.05
No. of reflections	5893
No. of parameters	398
H-atom treatment	H atoms treated by a mixture of independent and constrained refinement
Δρ_max, Δρ_min (e Å⁻³)	0.46, −0.38

Computer programs: APEX2 (Bruker, 2009), SAINT (Bruker, 2009), SHELXS97 (Sheldrick, 2008), SHELXL2014 (Sheldrick, 2015), PLATON (Spek, 2009) and publCIF (Westrip, 2010).

Footnotes

‡Additional correspondence author, e-mail: mustaffa@kimia.fs.utm.my.

Acknowledgements

The authors thank the Universiti Teknologi Malaysia (UTM) for financial support through vote numbers 03H06 & 03H81 and the Kurdistan Regional Government–Human Capacity Development Program (KRG–HCDP) for the scholarship to FKK.

References

Bondi, A. (1964). J. Phys. Chem. 68, 441–451. CrossRef CAS Web of Science Google Scholar
Brookhart, M., Green, M. L. H. & Parkin, G. (2007). Proc. Natl Acad. Sci. USA, 104, 6908–6914. Web of Science CrossRef PubMed CAS Google Scholar
Bruker (2009). APEX2, SAINT and SADABS. Bruker AXS Inc., Madison, Wisconsin, USA. Google Scholar
Jagadeesh, M., Lavanya, M., Kalangi, S. K., Sarala, Y., Ramachandraiah, C. & Reddy, A. V. (2015). Spectrochim. Acta Part A, 135, 180–184. CrossRef CAS Google Scholar
Li, M. X., Zhang, L. Z., Yang, M., Niu, J. Y. & Zhou, J. (2012). Bioorg. Med. Chem. Lett. 22, 2418–2423. CrossRef PubMed Google Scholar
Manikandan, R., Viswanathamurthi, P., Velmurugan, K., Nandhakumar, R., Hashimoto, T. & Endo, A. (2014). J. Photochem. Photobiol. B, 130, 205–216. CrossRef CAS PubMed Google Scholar
Oliveira, A. B. de, Feitosa, B. R. S., Näther, C. & Jess, I. (2014). Acta Cryst. E70, 101–103. CrossRef IUCr Journals Google Scholar
Pelosi, G., Bisceglie, F., Bignami, F., Ronzi, P., Schiavone, P., Re, M. C., Casoli, C. & Pilotti, E. (2010). J. Med. Chem. 53, 8765–8769. CrossRef CAS PubMed Google Scholar
Rowland, R. S. & Taylor, R. (1996). J. Phys. Chem. 100, 7384–7391. CSD CrossRef CAS Web of Science Google Scholar
Sampath, K., Sathiyaraj, S., Raja, G. & Jayabalakrishnan, C. (2013). J. Mol. Struct. 1046, 82–91. CrossRef CAS Google Scholar
Sankaraperumal, A., Karthikeyan, J., Nityananda Shetty, A. & Lakshmisundaram, R. (2013). Polyhedron, 50, 264–269. CrossRef CAS Google Scholar
Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122. Web of Science CrossRef CAS IUCr Journals Google Scholar
Sheldrick, G. M. (2015). Acta Cryst. A71, 3–8. Web of Science CrossRef IUCr Journals Google Scholar
Spek, A. L. (2009). Acta Cryst. D65, 148–155. Web of Science CrossRef CAS IUCr Journals Google Scholar
Suganthy, P. K., Prabhu, R. N. & Sridevi, V. S. (2013). Tetrahedron Lett. 54, 5695–5698. CrossRef CAS Google Scholar
Wang, J., Zong, Y., Wei, S. & Pan, Y. (2014). Appl. Organomet. Chem. 28, 351–353. CrossRef CAS Google Scholar
Westrip, S. P. (2010). J. Appl. Cryst. 43, 920–925. Web of Science CrossRef CAS IUCr Journals Google Scholar
Yousef, T. A., Abu El-Reash, G. M., Al-Jahdali, M. & El-Rakhawy, E. R. (2013). J. Mol. Struct. 1053, 15–21. CrossRef CAS Google Scholar

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Volume 72| Part 5| May 2016| Pages 760-763

doi:10.1107/S2056989016006873

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