Syntheses, crystal structures and Hirshfeld surface analyses of bis-(2-mercaptobenzimidazole)-bromo- and iodo-copper(I) complexes.

The title complexes, bromidobis(2,3-dihydro-1H-1,3-benzodiazole-2-thi-one)copper(I), [CuBr(C7H6N2S)2] (1), and bis(2,3-dihydro-1H-1,3-benzodiazole-2-thione)iodidocopper(I) acetone monosolvate, [CuI(C7H6N2S)2]·CH3COCH3 (2), were prepared by the reaction of copper(I) bromide/iodide with 2-mercaptobenzimidazole. Both complexes have mononuclear structures with the copper atom coordinated by two 2-mercaptobenzimidazole mol-ecules via their S atoms and one halide atom in an approximate trigonal-planar arrangement. In their extended structures, N-H⋯S hydrogen bonds and π-π contacts are found in both complexes; as a result of the acetone solvent mol-ecule in (2), N-H⋯O contacts are also observed. Hirshfeld surface analyses were carried out to aid in the visualization of these inter-actions, which showed that H⋯H contacts contribute 34.6% for (1) and 34.1% for (2) to the overall surface, followed by contributions from H⋯S/S⋯H, H⋯C/C⋯H and C⋯C contacts, respectively. As expected, H⋯O/O⋯H contacts are observed only in (2). The IR and 1H and 13C NMR spectra of (1) and (2) are described. © Chooto et al. 2022.

Chemical context

2-Mercaptobenzimidazole (C7H6N2S; bimztH2) has many uses including as an anti­oxidant to prevent rubber deterioration (Moldovan & Alexandrescu, 2002 ▸), an absorbant of mercury from industrial waste water in the form of 2-mercaptobenzimidazole-clay (Manohar et al., 2002 ▸), as a modifier of electrode surfaces to increase the efficiency of electrochemical analysis (Berchmans et al., 2000 ▸), as an inter­mediate in the production of the anti-inflammatory drug lanzoprazole (Wongwattana, 2004 ▸) and as a Cu corrosion inhibitor (Finšgar, 2013 ▸).

The preparation of bimztH2 involves the reaction between o-phenyl­enedi­amine and potassium ethyl xanthate in an ethanol–water mixture followed by reaction with acetic acid and water at 333–343 K (Vanallan & Deacon, 1971 ▸). The structure of bimztH2 exhibits tautomerism between its thione and thiol forms (Rout et al., 1984 ▸) as shown in the scheme below.

We now describe the syntheses and crystal structures of bimztH2 complexes with copper(I) halides, CuX (X = Br, I). It may be noted that the S atom of the ligand is a soft base and therefore favoured to form a coordinate bond with a soft acid such as copper(I). Hirshfeld surface analyses were performed to gain further insight into the inter­molecular inter­actions in these structures.

Structural commentary

The mononuclear structures of [Cu(bimztH2)2Br] (1) and [Cu(bimztH2)2I]·CH3COCH3 (2) are depicted in Fig. 1 ▸. Both complexes crystallize in the monoclinic system, space group P21/c. The copper ions adopt distorted trigonal–planar coord­ination geometries with one Cu—X bond (X = Br, I) and two Cu—S bonds, the lengths of which lie between 2.2189 (15) and 2.5479 (7) Å, being close to those found in complexes with a trigonal–planar geometry such as [Cu2(mimtH)5]2+ (Atkinson et al., 1985 ▸) and [Cu(SC6H5)3]2− (Coucouvanis et al., 1980 ▸). When comparing (1) and (2), the bond angles are distorted from the ideal values of 120° with greater distortion in (2) resulting from the presence of the acetone solvent mol­ecule and an N4—H4A⋯O1 hydrogen bond. The acetone mol­ecules in (2) result in weaker C=S bonds as supported by IR and 13C NMR data (vide infra). Both complexes feature a pair of intra­molecular N—H⋯X hydrogen bonds as listed in Tables 1 ▸ and 2 ▸ for (1) and (2), respectively.

Figure 1

The mol­ecular structures of (1) and (2) showing xx% [please supply] displacement ellipsoids.

Table 1

Hydrogen-bond geometry (Å, °) for (1)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
N1—H1A⋯S1i	0.70 (4)	2.69 (4)	3.384 (4)	170 (5)
N2—H2A⋯Br1	0.82 (4)	2.65 (4)	3.361 (4)	146 (4)
N4—H4A⋯Br1	0.84 (4)	2.54 (4)	3.364 (4)	166 (4)

Symmetry code: (i) .

Table 2

Hydrogen-bond geometry (Å, °) for (2)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
N1—H1A⋯I1	0.86 (2)	2.81 (2)	3.649 (4)	167 (6)
N2—H2A⋯S1i	0.86 (2)	2.47 (2)	3.331 (4)	176 (6)
N3—H3A⋯I1	0.85 (2)	2.91 (4)	3.666 (3)	148 (5)
N4—H4A⋯O1	0.85 (2)	2.02 (3)	2.840 (5)	161 (6)

Symmetry code: (i) .

Supra­molecular features

The supra­molecular assemblies in (1) and (2) (Tables 1 ▸ and 2 ▸) feature pairwise N—H⋯S hydrogen bonds, generating a graph-set (8) pattern with N1⋯S1i = 3.384 (4) Å for (1) and N2⋯S1i = 3.331 (4) Å for (2) [symmetry code: (i) −x + 1, −y + 1, −z + 1 for (1) and −x − 1, −y + 1, −z + 1 for (2)]. The acetone solvent mol­ecule in (2) leads to the formation of an N4—H4A⋯O1 hydrogen bond with N4⋯O1 = 2.840 (5) Å. The intra- and inter­molecular hydrogen-bond contacts of (1) and (2) are shown in Figs. 2 ▸ and 3 ▸, respectively. In addition, aromatic π–π stacking contacts are observed between adjacent imidazole rings (Cg1: N1/C1/N2/C7/C2 and Cg2: N3/C8/N4/C14/C9) and phenyl rings (Cg3: C2–C7 and Cg4: C9–C14) of neighbouring complex mol­ecules. The π–π inter­actions in the packing of (1) occur between Cg1–Cg3 (set 1) and Cg2–Cg4 (set 2) as inter-digitated [100] stacks with a minimum centroid–centroid separation of 3.566 (3) Å (Fig. 4 ▸), while in the packing of (2) (Fig. 5 ▸), corresponding Cg2–Cg4 inter­actions occur, which also leads to [100] stacks [minimum centroid–centroid separation = 3.608 (3) Å].

Figure 2

The intra- and inter mol­ecular hydrogen-bonding inter­actions of (1).

Figure 3

The intra- and inter mol­ecular hydrogen-bonding inter­actions of (2).

Figure 4

The inter­molecular π–π inter­actions in the crystal packing of (1) plotted down the c axis.

Figure 5

The inter­molecular π–π inter­actions in the crystal packing of (2) plotted down the b axis.

Hirshfeld surface analysis

The Hirshfeld surface (HS) analyses (HS mapped over d norm are shown in Fig. 6 ▸) and d and d fingerprint plots (Figs. 7 ▸ and 8 ▸) were generated using Crystal Explorer 17.5 (Turner et al., 2017 ▸). The red spots indicate the donors and acceptors of the hydrogen bonds, appearing close to H1A and S1 of the N1—H1A⋯S1 bond for (1) and close to H2A⋯S1 of the N2A-–H2A⋯S1 bond for (2). In addition, a red spot is found between H4A and O1 of the acetone solvent mol­ecule for (2). The fingerprint plots for (1) show that the principal inter­molecular contacts are H⋯H at 34.6% (Fig. 7 ▸ b), H⋯S /S⋯H at 16.4% (Fig. 7 ▸ c), H⋯C/C⋯H at 13.3% (Fig. 7 ▸ d) and C⋯C contacts at 7.2% (Fig. 7 ▸ e). For complex (2), the principal contacts are H⋯H at 34.1% (Fig. 8 ▸ b), H⋯C/C⋯H at 16.9% (Fig. 8 ▸ c), H⋯S / S⋯H at 12.1% (Fig. 8 ▸ d) and C⋯C contacts at 4.3% (Fig. 8 ▸ e) followed by H⋯O contacts at 3.5% (Fig. 8 ▸ f). As can be seen, H⋯H contacts predominate in both complexes, followed by H⋯S/S⋯H contacts for (1) and H⋯C/C⋯H contacts for (2). However, the C⋯C contacts differ significantly (by 3.7%) indicating that the π–π inter­molecular inter­actions in (1) are stronger than in (2).

Figure 6

Hirshfeld surfaces plotted over d norm showing the areas of inter­molecular hydrogen-bonding contacts of (1) and (2).

Figure 7

The fingerprint plots for (1).

Figure 8

The fingerprint plots for (2).

Database survey

2-Mercaptobenzimidazole has been found to form a complex with Pt, the bond formation being via the sulfur atom only with a square-planar geometry [Cambridge Structural Database (Groom et al., 2016 ▸) refcode GURMOV; Jolley et al., 2001 ▸]. In the case of the CoII complex, two sulfur atoms are bonded with the metal atom in a tetra­hedral coordination geometry (refcode ZOKYAZ; Ravikumar et al., 1995 ▸). CuI complexes with 2-mercaptobenzimidazole derivatives have been investigated as a model of copper proteins (refcodes QORGUZ, QORHAG and QORHEK; Balamurugan et al., 2001 ▸). A series of polynuclear clusters containing NiII and CoII (refcodes FOPVEN, FOPVIR and FOPXOZ; Han et al., 2015 ▸) of this ligand have been synthesized and the magnetic susceptibility of an NiII complex (FOPVEN) has been reported. The photophysical properties of the rigid structure of a hexa­nuclear CuI complex of 2-mercaptobenzimidazole constructed by S bridges has been studied (refcode COPNUT; Singh et al., 2017 ▸).

Synthesis, crystallization and chracterization

[Cu(bimztH

A mass of 0.19 g (1.2 mmol) of bimztH2 was placed in 30 ml of acetone at 318 K and stirred until completely dissolved to form a colourless solution. CuBr (0.09 g; 0.6 mmol) was added followed by further stirring for about 15 min to obtain a yellow solution, which was refluxed for 120 min at 353 K to become turbid with a light-yellow colour and then filtered. The colourless filtrate was left at room temperature for 3 days to form transparent needles and then filtered by vacuum suction to obtain 0.16 g of (1) (58% yield, m.p. 518–523 K). Elemental analysis (%): found (calculated); C = 38.32 (37.86), H = 2.78 (2.73), N = 12.17 (12.62), S = 14.71 (14.45).

[Cu(bimztH

The same procedure for (1) was followed except that 0.060 g of CuI (1.6 mmol) replaced the CuBr and 0.21 g of colourless needles of (2) were recovered (73%, yield, m.p. 518–523 K). Elemental analysis (%); found (calculated): C = 38.32 (37.86), H = 2.78 (2.73), N = 12.17 (12.62), S = 14.71 (14.45).

FT–IR spectra

Suzuki (1962 ▸) proposed that features in thio­amide IR spectra could be assigned to band I at 1395–1570 cm−1 arising from the N—H deformation and C—N stretching; band II at 1270–1420 cm−1 from C—N stretching, N—H deformation and C—H bending, band III at 940–1140 cm−1 from C—N and C=S stretching and band IV at 680–860 cm−1 due to C=S stretching (compare Jolley et al., 2001 ▸). Additionally, Raper et al. (1988 ▸) studied absorption bands of thio­amide in the complex prepared from bimzH2 and copper(II) perchlorate and found them at 1470 cm−1 (band I), 1360 cm−1 (band II), 1180 cm−1 (band III) and 740 cm−1 (band IV) compared with those of the free ligand at 1468 cm−1, 1357 cm−1, 1181 cm−1 and 744 + 713 cm−1, respectively. The broad absorption band at 3155 cm−1 is due to N—H stretching, which moves to a higher wavenumber and splits into two upon complexation.

For all our complexes, the FT–IR spectrum indicates the shift of bands I and II to a higher wavenumber, similar to the behaviour of N—H stretching due to the coordination through the sulfur atom and resulting charge transfer from N to S, which makes the N—H and C—N bonds stronger (Aslanidis et al., 2002 ▸). Band III of thio­amide for all complexes shifts to a lower wavenumber but this is hard to qu­antify because this area also covers C—N stretching. Band IV for C=S stretching changes significantly from 744 and 713 cm−1 in the free ligand to 734 cm−1 in the complex, reflecting copper–sulfur coordination. A change also occurs for the C—S bending mode at 602 cm−1 of C—S bending to lower wavenumber, corresponding with previous work (Raper et al., 1988 ▸). In the case of [Cu(bimztH2)2I]·CH3COCH3, the absorption bands at 1688 and 1384 cm−1 were found (figure not shown). After heating at 383 K for 10 minutes, these bands disappeared. Therefore these are due to C=O stretching and C—H bending, respectively, indicating the presence of acetone in the compound. IR data are summarized in Table 3 ▸.

Table 3

IR peak assignments (cm−1) for the bimztH2 ligand and (1) and (2)

Compound	ν(N—H)	Thio­amide band I	Thio­amide band II	Thio­amide band III	Thio­amide band IV	δ (C=S)
bimztH2	3155	1468	1357	1181	744, 713	602
(1)	3201, 3383	1470	1360	1180	734	598
(2)	3202, 3385	1470	1361	1175	734	598

1H NMR data for the ligand and (1) and (2) are listed in Table 4 ▸. The chemical shift at 13.28 ppm (br, s) belongs to two groups of N—H protons. The ratio of integration reveals that the two protons have the same environment. The ratio of N—H and aromatic protons is 1:2 without the signal of the S—H proton, indicating that both ligand and complex contain thione in DMSO-d 6 (Isab et al., 2003 ▸). Furthermore, the ligand exhibits chemical shifts around 7.49 ppm due to four methane protons on an aromatic benzene ring at positions H4, H7, H5, and H6, which change upon complex formation. The 13C NMR spectra of the ligand and complexes (Table 5 ▸) reveal seven carbon signals, including that of the thio­carbonyl group at 168.34 ppm, four carbon atoms in the aromatic ring at 109.75 and 122.59 ppm for C4,7 and C5,6, respectively, and two quarternary carbon atoms at 132.48 ppm. In the complex, C2 and C8,9 have upfield chemical shifts due to more electron shielding. The coordination via sulfur causes C=S to be weaker as well as the electron density to change from nitro­gen to C2, whereas C4,7 and C5,6 have downfield chemical shifts due to the electron transfer to C8,9, corresponding with the work of Isab et al. (2003 ▸). For (2), the carbonyl signal at 206.64 ppm and methane carbon at 30.86 ppm indicate the presence of acetone in the compound.

Table 4

1H NMR chemical shifts (p.p.m.) of the bimztH2 ligand, (1) and (2)

Compound	H4, H7	H5, H6	N—H
bimztH2	7.49 (4H, m)	7.49 (4H, m)	13.28 (br, s)
(1)	7.26 (2H, dd, J = 6.3 Hz)	7.19 (2H, dd, J = 5.5 Hz)	12.87 (br, s)
(2)	7.58 (2H, s)	7.58 (2H, s)	13.57 (br, s)

Table 5

13C NMR chemical shifts (p.p.m.) of the bimztH2 ligand and (1) and (2)

Compound	C2 (C=S)	C4,7 (CH)	C5,6 (CH)	C8,9 (C)
bimztH2	168.34	109.75	122.59	132.48
(1)	165.11	110.35	123.06	132.06
(2)	164.10	110.65	123.29	131.96

Refinement

Crystal data, data collection and structure refinement details are summarized in Table 6 ▸. All H atoms of (1) were clearly resolved in difference-density maps and all H-atom parameters were freely refined. For (2), the carbon-bound H atoms were placed in calculated locations with C—H = 0.93–0.96 Å and refined as riding atoms with U iso(H) = 1.2U eq(C) or 1.5U eq(methyl C). The H-atom positions of the amide groups of (2) were found in difference maps and refined with N—H distances restained to 0.85 (2) and 0.86 (2) Å.

Table 6

Experimental details

	(1)	(2)
Crystal data
Chemical formula	[CuBr(C7H5N2S)2]	[CuI(C7H6N2S)2]·C3H6O
M r	443.85	548.91
Crystal system, space group	Monoclinic, P21/c	Monoclinic, P21/c
Temperature (K)	293	293
a, b, c (Å)	4.1549 (4), 28.708 (3), 13.2735 (13)	4.5154 (3), 22.2157 (15), 20.4062 (14)
β (°)	95.564 (2)	94.818 (1)
V (Å3)	1575.8 (3)	2039.8 (2)
Z	4	4
Radiation type	Mo Kα	Mo Kα
μ (mm−1)	4.19	2.80
Crystal size (mm)	0.46 × 0.05 × 0.04	0.38 × 0.14 × 0.08
Data collection
Diffractometer	Bruker CCD area detector	Bruker CCD area detector
Absorption correction	Multi-scan (SADABS; Bruker, 2003 ▸)	Multi-scan (SADABS; Bruker, 2003 ▸)
T min, T max	0.713, 1.000	0.749, 1.000
No. of measured, independent and observed [I > 2σ(I)] reflections	11218, 2750, 2200	14555, 3597, 3200
R int	0.039	0.021
(sin θ/λ)max (Å−1)	0.595	0.595
Refinement
R[F 2 > 2σ(F 2)], wR(F 2), S	0.041, 0.093, 1.08	0.039, 0.089, 1.08
No. of reflections	2750	3597
No. of parameters	247	247
No. of restraints	0	4
H-atom treatment	All H-atom parameters refined	H atoms treated by a mixture of independent and constrained refinement
Δρmax, Δρmin (e Å−3)	0.66, −0.39	1.14, −0.90

Computer programs: SMART and SAINT (Bruker, 2003 ▸), SHELXT (Sheldrick, 2015a ▸), SHELXL2018/3 (Sheldrick, 2015b ▸), Mercury (Macrae et al., 2020 ▸), WinGX publication routines (Farrugia, 2012 ▸) and publCIF (Westrip, 2010 ▸).

Crystal structure: contains datablock(s) 1, 2, global. DOI: 10.1107/S2056989022004224/hb7984sup1.cif

Structure factors: contains datablock(s) 1. DOI: 10.1107/S2056989022004224/hb79841sup2.hkl

Structure factors: contains datablock(s) 2. DOI: 10.1107/S2056989022004224/hb79842sup3.hkl

CCDC references: 2167595, 2167594

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

[CuBr(C7H5N2S)2]	F(000) = 880
Mr = 443.85	Dx = 1.871 Mg m−3
Monoclinic, P21/c	Mo Kα radiation, λ = 0.71073 Å
a = 4.1549 (4) Å	Cell parameters from 2031 reflections
b = 28.708 (3) Å	θ = 2.6–21.8°
c = 13.2735 (13) Å	µ = 4.19 mm−1
β = 95.564 (2)°	T = 293 K
V = 1575.8 (3) Å3	Needle, colourless
Z = 4	0.46 × 0.05 × 0.04 mm

Bruker CCD area detector diffractometer	2750 independent reflections
Radiation source: fine-focus sealed tube	2200 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.039
Frames, each covering 0.3 ° in ω scans	θmax = 25.0°, θmin = 1.7°
Absorption correction: multi-scan (SADABS; Bruker, 2003)	h = −4→4
Tmin = 0.713, Tmax = 1.000	k = −34→33
11218 measured reflections	l = −15→15

Refinement on F2	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F2 > 2σ(F2)] = 0.041	Hydrogen site location: difference Fourier map
wR(F2) = 0.093	All H-atom parameters refined
S = 1.08	w = 1/[σ2(Fo2) + (0.0446P)2 + 0.5475P] where P = (Fo2 + 2Fc2)/3
2750 reflections	(Δ/σ)max < 0.001
247 parameters	Δρmax = 0.66 e Å−3
0 restraints	Δρmin = −0.39 e Å−3

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.

	x	y	z	Uiso*/Ueq
Br1	0.35082 (11)	0.31949 (2)	0.29213 (3)	0.04740 (17)
Cu1	0.35888 (16)	0.34728 (2)	0.46565 (5)	0.0570 (2)
S1	0.5237 (3)	0.42049 (4)	0.50112 (9)	0.0489 (3)
N1	0.7906 (10)	0.48624 (13)	0.3871 (3)	0.0439 (10)
C1	0.7004 (10)	0.44151 (14)	0.4012 (3)	0.0399 (10)
S2	0.1419 (4)	0.30563 (5)	0.58260 (10)	0.0688 (4)
N2	0.7887 (9)	0.41786 (13)	0.3211 (3)	0.0414 (9)
C2	0.9318 (10)	0.49139 (15)	0.2975 (3)	0.0407 (10)
N3	−0.1802 (11)	0.22338 (14)	0.5747 (3)	0.0527 (11)
C3	1.0529 (12)	0.52902 (17)	0.2500 (4)	0.0545 (13)
N4	−0.0687 (9)	0.24669 (13)	0.4289 (3)	0.0444 (9)
C4	1.1761 (13)	0.52084 (19)	0.1592 (4)	0.0595 (14)
C5	1.1740 (12)	0.47661 (19)	0.1173 (4)	0.0572 (13)
C6	1.0519 (12)	0.43907 (19)	0.1639 (4)	0.0528 (12)
C7	0.9299 (10)	0.44709 (15)	0.2558 (3)	0.0395 (10)
C8	−0.0348 (11)	0.25789 (15)	0.5269 (3)	0.0463 (11)
C9	−0.3156 (10)	0.19077 (14)	0.5067 (3)	0.0393 (10)
C10	−0.4919 (13)	0.15060 (17)	0.5169 (4)	0.0530 (13)
C11	−0.5958 (13)	0.12685 (18)	0.4308 (4)	0.0560 (13)
C12	−0.5244 (14)	0.14225 (19)	0.3371 (4)	0.0623 (14)
C13	−0.3471 (14)	0.18181 (19)	0.3265 (4)	0.0610 (14)
C14	−0.2427 (10)	0.20588 (15)	0.4124 (3)	0.0411 (10)
H1A	0.734 (10)	0.5041 (15)	0.417 (3)	0.032 (13)*
H2A	0.764 (10)	0.3900 (16)	0.310 (3)	0.049 (14)*
H3	1.054 (10)	0.5568 (15)	0.282 (3)	0.045 (12)*
H3A	−0.203 (10)	0.2208 (15)	0.631 (3)	0.038 (14)*
H4	1.259 (12)	0.5470 (17)	0.126 (4)	0.069 (16)*
H4A	0.008 (9)	0.2643 (14)	0.387 (3)	0.033 (11)*
H5	1.263 (12)	0.4737 (16)	0.057 (4)	0.062 (15)*
H6	1.045 (12)	0.4107 (18)	0.139 (4)	0.073 (17)*
H10	−0.542 (11)	0.1438 (16)	0.573 (4)	0.051 (14)*
H11	−0.727 (13)	0.0991 (19)	0.436 (4)	0.082 (18)*
H12	−0.591 (11)	0.1243 (17)	0.284 (4)	0.065 (16)*
H13	−0.285 (11)	0.1901 (16)	0.269 (4)	0.052 (14)*

	U11	U22	U33	U12	U13	U23
Br1	0.0583 (3)	0.0418 (3)	0.0432 (3)	−0.0072 (2)	0.0106 (2)	−0.0012 (2)
Cu1	0.0745 (5)	0.0403 (3)	0.0586 (4)	−0.0038 (3)	0.0192 (3)	−0.0036 (3)
S1	0.0628 (8)	0.0383 (6)	0.0469 (7)	0.0016 (5)	0.0115 (6)	−0.0075 (5)
N1	0.050 (2)	0.030 (2)	0.051 (3)	0.0076 (18)	0.0024 (19)	−0.0082 (19)
C1	0.035 (2)	0.033 (2)	0.049 (3)	0.0086 (19)	−0.0047 (19)	−0.006 (2)
S2	0.1016 (11)	0.0582 (8)	0.0498 (8)	−0.0207 (8)	0.0242 (7)	−0.0117 (6)
N2	0.050 (2)	0.028 (2)	0.047 (2)	0.0024 (17)	0.0089 (17)	−0.0078 (17)
C2	0.039 (2)	0.037 (2)	0.045 (3)	0.0032 (19)	−0.002 (2)	−0.001 (2)
N3	0.077 (3)	0.046 (2)	0.037 (3)	−0.001 (2)	0.022 (2)	0.006 (2)
C3	0.062 (3)	0.035 (3)	0.064 (3)	−0.002 (2)	−0.005 (3)	0.001 (2)
N4	0.055 (2)	0.044 (2)	0.035 (2)	−0.0042 (19)	0.0065 (18)	0.0093 (18)
C4	0.058 (3)	0.058 (3)	0.063 (4)	−0.009 (3)	0.003 (3)	0.015 (3)
C5	0.049 (3)	0.069 (4)	0.055 (3)	0.002 (3)	0.011 (3)	0.001 (3)
C6	0.053 (3)	0.048 (3)	0.058 (3)	0.003 (2)	0.008 (2)	−0.005 (3)
C7	0.035 (2)	0.038 (2)	0.045 (3)	0.0021 (18)	0.0008 (19)	−0.003 (2)
C8	0.053 (3)	0.042 (3)	0.046 (3)	0.009 (2)	0.012 (2)	0.007 (2)
C9	0.042 (2)	0.038 (2)	0.039 (2)	0.0065 (19)	0.0125 (19)	0.0053 (19)
C10	0.062 (3)	0.049 (3)	0.052 (3)	0.001 (2)	0.028 (3)	0.012 (3)
C11	0.060 (3)	0.040 (3)	0.068 (4)	−0.002 (2)	0.012 (3)	0.004 (3)
C12	0.075 (4)	0.053 (3)	0.057 (4)	−0.011 (3)	−0.003 (3)	−0.001 (3)
C13	0.079 (4)	0.063 (4)	0.041 (3)	−0.010 (3)	0.003 (3)	0.009 (3)
C14	0.043 (3)	0.042 (3)	0.038 (3)	0.004 (2)	0.004 (2)	0.004 (2)

Br1—Cu1	2.4346 (8)	N4—C14	1.383 (6)
Cu1—S2	2.2189 (15)	N4—H4A	0.84 (4)
Cu1—S1	2.2464 (13)	C4—C5	1.386 (7)
S1—C1	1.688 (5)	C4—H4	0.95 (5)
N1—C1	1.356 (6)	C5—C6	1.364 (7)
N1—C2	1.384 (6)	C5—H5	0.92 (5)
N1—H1A	0.70 (4)	C6—C7	1.386 (6)
C1—N2	1.342 (5)	C6—H6	0.88 (5)
S2—C8	1.691 (5)	C9—C10	1.380 (6)
N2—C7	1.378 (5)	C9—C14	1.386 (6)
N2—H2A	0.82 (4)	C10—C11	1.365 (7)
C2—C3	1.371 (6)	C10—H10	0.82 (5)
C2—C7	1.387 (6)	C11—C12	1.378 (7)
N3—C8	1.350 (6)	C11—H11	0.97 (5)
N3—C9	1.381 (6)	C12—C13	1.368 (7)
N3—H3A	0.76 (4)	C12—H12	0.90 (5)
C3—C4	1.374 (7)	C13—C14	1.367 (7)
C3—H3	0.90 (4)	C13—H13	0.86 (4)
N4—C8	1.334 (6)
S2—Cu1—S1	119.59 (5)	C6—C5—H5	121 (3)
S2—Cu1—Br1	121.07 (4)	C4—C5—H5	117 (3)
S1—Cu1—Br1	118.74 (4)	C5—C6—C7	116.8 (5)
C1—S1—Cu1	108.47 (15)	C5—C6—H6	124 (3)
C1—N1—C2	111.5 (4)	C7—C6—H6	119 (3)
C1—N1—H1A	120 (4)	N2—C7—C6	131.9 (4)
C2—N1—H1A	127 (4)	N2—C7—C2	107.1 (4)
N2—C1—N1	105.6 (4)	C6—C7—C2	121.0 (4)
N2—C1—S1	127.9 (3)	N4—C8—N3	105.8 (4)
N1—C1—S1	126.5 (3)	N4—C8—S2	128.4 (3)
C8—S2—Cu1	108.64 (16)	N3—C8—S2	125.8 (4)
C1—N2—C7	110.9 (4)	C10—C9—N3	133.5 (4)
C1—N2—H2A	127 (3)	C10—C9—C14	121.0 (4)
C7—N2—H2A	122 (3)	N3—C9—C14	105.5 (4)
C3—C2—N1	133.2 (4)	C11—C10—C9	117.6 (5)
C3—C2—C7	121.8 (4)	C11—C10—H10	124 (3)
N1—C2—C7	105.0 (4)	C9—C10—H10	118 (3)
C8—N3—C9	111.3 (4)	C10—C11—C12	121.1 (5)
C8—N3—H3A	129 (3)	C10—C11—H11	119 (3)
C9—N3—H3A	119 (3)	C12—C11—H11	120 (3)
C2—C3—C4	117.0 (5)	C13—C12—C11	121.6 (6)
C2—C3—H3	118 (3)	C13—C12—H12	121 (3)
C4—C3—H3	125 (3)	C11—C12—H12	117 (3)
C8—N4—C14	111.2 (4)	C14—C13—C12	117.7 (5)
C8—N4—H4A	120 (3)	C14—C13—H13	120 (3)
C14—N4—H4A	129 (3)	C12—C13—H13	122 (3)
C3—C4—C5	121.3 (5)	C13—C14—N4	132.8 (4)
C3—C4—H4	117 (3)	C13—C14—C9	121.0 (4)
C5—C4—H4	122 (3)	N4—C14—C9	106.2 (4)
C6—C5—C4	122.0 (5)
C2—N1—C1—N2	0.9 (5)	C14—N4—C8—N3	1.7 (5)
C2—N1—C1—S1	179.3 (3)	C14—N4—C8—S2	−176.8 (3)
Cu1—S1—C1—N2	−11.7 (4)	C9—N3—C8—N4	−1.8 (5)
Cu1—S1—C1—N1	170.2 (3)	C9—N3—C8—S2	176.7 (3)
N1—C1—N2—C7	−0.8 (5)	Cu1—S2—C8—N4	−4.7 (5)
S1—C1—N2—C7	−179.2 (3)	Cu1—S2—C8—N3	177.1 (4)
C1—N1—C2—C3	178.4 (5)	C8—N3—C9—C10	−178.4 (5)
C1—N1—C2—C7	−0.7 (5)	C8—N3—C9—C14	1.2 (5)
N1—C2—C3—C4	−179.6 (5)	N3—C9—C10—C11	178.5 (5)
C7—C2—C3—C4	−0.7 (7)	C14—C9—C10—C11	−1.1 (7)
C2—C3—C4—C5	0.7 (8)	C9—C10—C11—C12	0.6 (8)
C3—C4—C5—C6	−0.3 (8)	C10—C11—C12—C13	0.0 (9)
C4—C5—C6—C7	−0.2 (8)	C11—C12—C13—C14	−0.2 (9)
C1—N2—C7—C6	−178.7 (5)	C12—C13—C14—N4	−178.5 (5)
C1—N2—C7—C2	0.4 (5)	C12—C13—C14—C9	−0.3 (7)
C5—C6—C7—N2	179.3 (5)	C8—N4—C14—C13	177.4 (5)
C5—C6—C7—C2	0.3 (7)	C8—N4—C14—C9	−1.0 (5)
C3—C2—C7—N2	−179.0 (4)	C10—C9—C14—C13	0.9 (7)
N1—C2—C7—N2	0.2 (4)	N3—C9—C14—C13	−178.7 (4)
C3—C2—C7—C6	0.2 (7)	C10—C9—C14—N4	179.5 (4)
N1—C2—C7—C6	179.4 (4)	N3—C9—C14—N4	−0.2 (5)

D—H···A	D—H	H···A	D···A	D—H···A
N1—H1A···S1i	0.70 (4)	2.69 (4)	3.384 (4)	170 (5)
N2—H2A···Br1	0.82 (4)	2.65 (4)	3.361 (4)	146 (4)
N4—H4A···Br1	0.84 (4)	2.54 (4)	3.364 (4)	166 (4)

[CuI(C7H6N2S)2]·C3H6O	F(000) = 1080
Mr = 548.91	Dx = 1.787 Mg m−3
Monoclinic, P21/c	Mo Kα radiation, λ = 0.71073 Å
a = 4.5154 (3) Å	Cell parameters from 5872 reflections
b = 22.2157 (15) Å	θ = 2.2–26.6°
c = 20.4062 (14) Å	µ = 2.80 mm−1
β = 94.818 (1)°	T = 293 K
V = 2039.8 (2) Å3	Needle, colourless
Z = 4	0.38 × 0.14 × 0.08 mm

Bruker CCD area detector diffractometer	3597 independent reflections
Radiation source: fine-focus sealed tube	3200 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.021
Frames, each covering 0.3 ° in ω scans	θmax = 25.0°, θmin = 1.4°
Absorption correction: multi-scan (SADABS; Bruker, 2003)	h = −5→5
Tmin = 0.749, Tmax = 1.000	k = −26→26
14555 measured reflections	l = −24→24

Refinement on F2	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F2 > 2σ(F2)] = 0.039	Hydrogen site location: mixed
wR(F2) = 0.089	H atoms treated by a mixture of independent and constrained refinement
S = 1.08	w = 1/[σ2(Fo2) + (0.0315P)2 + 4.5225P] where P = (Fo2 + 2Fc2)/3
3597 reflections	(Δ/σ)max = 0.002
247 parameters	Δρmax = 1.14 e Å−3
4 restraints	Δρmin = −0.90 e Å−3

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.

	x	y	z	Uiso*/Ueq
Cu1	0.2323 (2)	0.42788 (3)	0.63559 (3)	0.0789 (2)
I1	0.34973 (7)	0.31632 (2)	0.65076 (2)	0.06112 (13)
S1	−0.1755 (4)	0.45699 (6)	0.57174 (7)	0.0838 (5)
S2	0.3444 (3)	0.50247 (5)	0.70750 (6)	0.0518 (3)
N1	−0.1238 (9)	0.35326 (17)	0.50250 (18)	0.0544 (9)
N2	−0.4365 (10)	0.41666 (16)	0.45551 (19)	0.0555 (10)
N3	0.7524 (8)	0.42258 (15)	0.76321 (17)	0.0454 (8)
N4	0.6946 (8)	0.50239 (16)	0.82129 (18)	0.0483 (8)
C1	−0.2443 (12)	0.4079 (2)	0.5087 (2)	0.0548 (11)
C2	−0.2433 (10)	0.32568 (19)	0.4450 (2)	0.0476 (10)
C3	−0.1898 (11)	0.2710 (2)	0.4161 (2)	0.0557 (11)
H3	−0.054352	0.243569	0.435797	0.067*
C4	−0.3470 (11)	0.2590 (2)	0.3568 (2)	0.0592 (12)
H4	−0.316081	0.222687	0.335867	0.071*
C5	−0.5483 (12)	0.2993 (2)	0.3277 (2)	0.0610 (13)
H5	−0.651343	0.289205	0.287859	0.073*
C6	−0.6020 (12)	0.3539 (2)	0.3555 (2)	0.0579 (12)
H6	−0.737871	0.381133	0.335589	0.070*
C7	−0.4427 (10)	0.36649 (18)	0.4150 (2)	0.0479 (10)
C8	0.6017 (9)	0.47473 (18)	0.7644 (2)	0.0442 (10)
C9	0.9438 (9)	0.41641 (18)	0.8198 (2)	0.0438 (9)
C10	1.1416 (10)	0.3719 (2)	0.8413 (2)	0.0541 (11)
H10	1.170348	0.337767	0.816134	0.065*
C11	1.2951 (11)	0.3804 (2)	0.9021 (3)	0.0619 (13)
H11	1.428668	0.351140	0.918471	0.074*
C12	1.2554 (11)	0.4315 (2)	0.9394 (2)	0.0620 (13)
H12	1.362526	0.435638	0.980133	0.074*
C13	1.0610 (10)	0.4761 (2)	0.9175 (2)	0.0550 (11)
H13	1.035593	0.510598	0.942271	0.066*
C14	0.9046 (9)	0.46766 (19)	0.8569 (2)	0.0458 (10)
C15	0.1969 (15)	0.6773 (3)	0.9353 (3)	0.0795 (17)
H15A	0.041024	0.704543	0.919993	0.119*
H15B	0.126452	0.650874	0.967768	0.119*
H15C	0.363937	0.699853	0.954390	0.119*
C16	0.2888 (11)	0.6414 (2)	0.8792 (2)	0.0553 (11)
C17	0.1359 (14)	0.6534 (3)	0.8138 (3)	0.0797 (16)
H17A	−0.010436	0.684287	0.817434	0.120*
H17B	0.278159	0.666406	0.784409	0.120*
H17C	0.040343	0.617277	0.797060	0.120*
O1	0.4835 (9)	0.60411 (17)	0.88765 (19)	0.0792 (11)
H1A	−0.007 (11)	0.339 (3)	0.534 (2)	0.095*
H2A	−0.543 (12)	0.4484 (18)	0.449 (3)	0.095*
H3A	0.733 (14)	0.398 (2)	0.731 (2)	0.095*
H4A	0.617 (13)	0.5354 (16)	0.832 (3)	0.095*

	U11	U22	U33	U12	U13	U23
Cu1	0.1375 (7)	0.0464 (4)	0.0480 (3)	0.0166 (4)	−0.0207 (4)	−0.0050 (3)
I1	0.0590 (2)	0.03985 (18)	0.0816 (3)	0.00121 (13)	−0.01114 (16)	−0.00181 (14)
S1	0.1445 (14)	0.0479 (7)	0.0528 (7)	0.0360 (8)	−0.0277 (8)	−0.0143 (6)
S2	0.0627 (7)	0.0405 (6)	0.0517 (6)	0.0037 (5)	0.0028 (5)	−0.0012 (5)
N1	0.077 (3)	0.040 (2)	0.045 (2)	0.0109 (19)	−0.0036 (19)	−0.0014 (16)
N2	0.078 (3)	0.039 (2)	0.049 (2)	0.0103 (19)	−0.0031 (19)	−0.0006 (17)
N3	0.049 (2)	0.0382 (19)	0.050 (2)	0.0005 (16)	0.0054 (16)	−0.0060 (15)
N4	0.057 (2)	0.039 (2)	0.049 (2)	0.0016 (17)	0.0093 (17)	−0.0059 (17)
C1	0.083 (3)	0.039 (2)	0.042 (2)	0.009 (2)	0.001 (2)	−0.0012 (19)
C2	0.061 (3)	0.040 (2)	0.043 (2)	−0.003 (2)	0.012 (2)	0.0001 (18)
C3	0.066 (3)	0.041 (2)	0.062 (3)	0.004 (2)	0.014 (2)	−0.005 (2)
C4	0.077 (3)	0.044 (3)	0.059 (3)	−0.011 (2)	0.018 (3)	−0.014 (2)
C5	0.078 (3)	0.055 (3)	0.050 (3)	−0.018 (3)	0.006 (2)	−0.007 (2)
C6	0.072 (3)	0.049 (3)	0.051 (3)	−0.008 (2)	−0.002 (2)	0.004 (2)
C7	0.064 (3)	0.037 (2)	0.043 (2)	−0.004 (2)	0.010 (2)	0.0021 (18)
C8	0.045 (2)	0.040 (2)	0.049 (2)	−0.0065 (18)	0.0120 (19)	−0.0023 (18)
C9	0.043 (2)	0.042 (2)	0.047 (2)	−0.0049 (18)	0.0097 (18)	−0.0012 (18)
C10	0.055 (3)	0.049 (3)	0.060 (3)	0.002 (2)	0.010 (2)	−0.004 (2)
C11	0.058 (3)	0.063 (3)	0.065 (3)	0.009 (2)	0.005 (2)	0.007 (2)
C12	0.060 (3)	0.077 (3)	0.049 (3)	−0.002 (3)	0.003 (2)	−0.001 (2)
C13	0.060 (3)	0.057 (3)	0.048 (3)	−0.003 (2)	0.009 (2)	−0.008 (2)
C14	0.045 (2)	0.043 (2)	0.051 (2)	−0.0016 (19)	0.0104 (19)	−0.0014 (19)
C15	0.100 (4)	0.072 (4)	0.067 (3)	0.025 (3)	0.007 (3)	−0.006 (3)
C16	0.063 (3)	0.046 (3)	0.057 (3)	0.001 (2)	0.007 (2)	−0.004 (2)
C17	0.088 (4)	0.088 (4)	0.064 (3)	0.006 (3)	0.006 (3)	0.001 (3)
O1	0.094 (3)	0.065 (2)	0.077 (2)	0.029 (2)	−0.002 (2)	−0.0166 (19)

Cu1—S2	2.2430 (13)	C5—C6	1.369 (7)
Cu1—S1	2.2594 (17)	C5—H5	0.9300
Cu1—I1	2.5479 (7)	C6—C7	1.386 (6)
S1—C1	1.696 (4)	C6—H6	0.9300
S2—C8	1.689 (4)	C9—C10	1.380 (6)
N1—C1	1.341 (6)	C9—C14	1.387 (6)
N1—C2	1.391 (6)	C10—C11	1.383 (7)
N1—H1A	0.86 (2)	C10—H10	0.9300
N2—C1	1.345 (6)	C11—C12	1.386 (7)
N2—C7	1.387 (5)	C11—H11	0.9300
N2—H2A	0.86 (2)	C12—C13	1.374 (7)
N3—C8	1.345 (5)	C12—H12	0.9300
N3—C9	1.390 (5)	C13—C14	1.384 (6)
N3—H3A	0.85 (2)	C13—H13	0.9300
N4—C8	1.348 (5)	C15—C16	1.484 (7)
N4—C14	1.381 (6)	C15—H15A	0.9600
N4—H4A	0.85 (2)	C15—H15B	0.9600
C2—C3	1.381 (6)	C15—H15C	0.9600
C2—C7	1.384 (6)	C16—O1	1.209 (6)
C3—C4	1.376 (7)	C16—C17	1.474 (7)
C3—H3	0.9300	C17—H17A	0.9600
C4—C5	1.375 (7)	C17—H17B	0.9600
C4—H4	0.9300	C17—H17C	0.9600
S2—Cu1—S1	107.10 (5)	N2—C7—C6	131.8 (4)
S2—Cu1—I1	127.30 (4)	N3—C8—N4	106.7 (4)
S1—Cu1—I1	119.98 (5)	N3—C8—S2	128.4 (3)
C1—S1—Cu1	110.01 (18)	N4—C8—S2	124.9 (3)
C8—S2—Cu1	106.54 (15)	C10—C9—C14	121.6 (4)
C1—N1—C2	110.3 (4)	C10—C9—N3	132.5 (4)
C1—N1—H1A	120 (4)	C14—C9—N3	105.9 (4)
C2—N1—H1A	129 (4)	C9—C10—C11	116.6 (4)
C1—N2—C7	110.1 (4)	C9—C10—H10	121.7
C1—N2—H2A	124 (4)	C11—C10—H10	121.7
C7—N2—H2A	126 (4)	C10—C11—C12	121.8 (5)
C8—N3—C9	110.5 (3)	C10—C11—H11	119.1
C8—N3—H3A	123 (4)	C12—C11—H11	119.1
C9—N3—H3A	126 (4)	C13—C12—C11	121.3 (5)
C8—N4—C14	110.4 (4)	C13—C12—H12	119.3
C8—N4—H4A	121 (4)	C11—C12—H12	119.3
C14—N4—H4A	128 (4)	C12—C13—C14	117.2 (4)
N1—C1—N2	107.1 (4)	C12—C13—H13	121.4
N1—C1—S1	127.1 (4)	C14—C13—H13	121.4
N2—C1—S1	125.7 (3)	N4—C14—C13	132.1 (4)
C3—C2—C7	121.2 (4)	N4—C14—C9	106.6 (4)
C3—C2—N1	132.7 (4)	C13—C14—C9	121.4 (4)
C7—C2—N1	106.1 (4)	C16—C15—H15A	109.5
C4—C3—C2	116.7 (5)	C16—C15—H15B	109.5
C4—C3—H3	121.7	H15A—C15—H15B	109.5
C2—C3—H3	121.7	C16—C15—H15C	109.5
C5—C4—C3	121.9 (4)	H15A—C15—H15C	109.5
C5—C4—H4	119.1	H15B—C15—H15C	109.5
C3—C4—H4	119.1	O1—C16—C17	122.2 (5)
C6—C5—C4	122.1 (5)	O1—C16—C15	120.4 (5)
C6—C5—H5	119.0	C17—C16—C15	117.4 (5)
C4—C5—H5	119.0	C16—C17—H17A	109.5
C5—C6—C7	116.4 (5)	C16—C17—H17B	109.5
C5—C6—H6	121.8	H17A—C17—H17B	109.5
C7—C6—H6	121.8	C16—C17—H17C	109.5
C2—C7—N2	106.4 (4)	H17A—C17—H17C	109.5
C2—C7—C6	121.7 (4)	H17B—C17—H17C	109.5
C2—N1—C1—N2	−1.0 (6)	C9—N3—C8—N4	0.1 (5)
C2—N1—C1—S1	178.0 (4)	C9—N3—C8—S2	−179.9 (3)
C7—N2—C1—N1	0.9 (6)	C14—N4—C8—N3	−0.3 (5)
C7—N2—C1—S1	−178.2 (4)	C14—N4—C8—S2	179.6 (3)
Cu1—S1—C1—N1	13.2 (5)	Cu1—S2—C8—N3	10.3 (4)
Cu1—S1—C1—N2	−168.0 (4)	Cu1—S2—C8—N4	−169.7 (3)
C1—N1—C2—C3	178.4 (5)	C8—N3—C9—C10	−180.0 (5)
C1—N1—C2—C7	0.8 (5)	C8—N3—C9—C14	0.2 (5)
C7—C2—C3—C4	−0.8 (7)	C14—C9—C10—C11	1.0 (7)
N1—C2—C3—C4	−178.1 (5)	N3—C9—C10—C11	−178.8 (4)
C2—C3—C4—C5	−0.2 (7)	C9—C10—C11—C12	−0.7 (7)
C3—C4—C5—C6	0.8 (8)	C10—C11—C12—C13	−0.1 (8)
C4—C5—C6—C7	−0.2 (7)	C11—C12—C13—C14	0.6 (7)
C3—C2—C7—N2	−178.2 (4)	C8—N4—C14—C13	−179.3 (5)
N1—C2—C7—N2	−0.3 (5)	C8—N4—C14—C9	0.4 (5)
C3—C2—C7—C6	1.4 (7)	C12—C13—C14—N4	179.3 (5)
N1—C2—C7—C6	179.3 (4)	C12—C13—C14—C9	−0.3 (7)
C1—N2—C7—C2	−0.4 (5)	C10—C9—C14—N4	179.8 (4)
C1—N2—C7—C6	−179.9 (5)	N3—C9—C14—N4	−0.4 (4)
C5—C6—C7—C2	−0.8 (7)	C10—C9—C14—C13	−0.5 (7)
C5—C6—C7—N2	178.6 (5)	N3—C9—C14—C13	179.4 (4)

D—H···A	D—H	H···A	D···A	D—H···A
N1—H1A···I1	0.86 (2)	2.81 (2)	3.649 (4)	167 (6)
N2—H2A···S1i	0.86 (2)	2.47 (2)	3.331 (4)	176 (6)
N3—H3A···I1	0.85 (2)	2.91 (4)	3.666 (3)	148 (5)
N4—H4A···O1	0.85 (2)	2.02 (3)	2.840 (5)	161 (6)
C15—H15A···I1ii	0.96	3.31	4.240 (6)	165