Bis(1,3-benzothia­zol-2-amine-κN 3)silver(I) nitrate acetone solvate

Christoph E Strasser; Leigh-Anne de Jongh; Stephanie Cronje; Helgard G Raubenheimer

doi:10.1107/S1600536809004176

. 2009 Feb 11;65(Pt 3):m265–m266. doi: 10.1107/S1600536809004176

Bis(1,3-benzothiazol-2-amine-κN ³)silver(I) nitrate acetone solvate

Christoph E Strasser ^a, Leigh-Anne de Jongh ^a, Stephanie Cronje ^a,^*, Helgard G Raubenheimer ^a

PMCID: PMC2968676 PMID: 21582055

Abstract

In the title compound, [Ag(C₇H₆N₂S)₂]NO₃·C₃H₆O, the Ag^I ion is coordinated to two benzothiazol-2-amine ligands via the thiazole N atoms in an approximately linear arrangement. The dihedral angle between the mean planes of the two 1,3-benzothiazole groups is 5.9 (3)°. Both amine groups on the ligands are oriented in the same direction and are engaged in N—H⋯O hydrogen bonding with the nitrate counter-anion, forming one-dimensional columns along the b-axis direction. Voids created by inefficient crystal packing are occupied by acetone solvent molecules which are disordered over two sites with occupancies of 0.563 (11) and 0.437 (11).

Related literature

For general background, see: de Jongh et al. (2008 ▶); Tewari et al. (1991 ▶). For related structures, see: Ellsworth et al. (2006 ▶); Fackler et al. (1992 ▶); Fitchett & Steel (2000 ▶); Hiraoka et al. (2003 ▶); Manzoni de Oliveira et al. (2007 ▶); Murthy & Murthy (1976 ▶); Zou et al. (2004 ▶).

Experimental

Crystal data

[Ag(C₇H₆N₂S)₂]NO₃·C₃H₆O
M _r = 528.35
Monoclinic,
a = 17.096 (4) Å
b = 5.8166 (12) Å
c = 20.421 (4) Å
β = 102.867 (3)°
V = 1979.8 (7) Å³
Z = 4
Mo Kα radiation
μ = 1.27 mm⁻¹
T = 100 (2) K
0.20 × 0.08 × 0.05 mm

Data collection

Bruker APEX CCD area-detector diffractometer
Absorption correction: multi-scan (SADABS; Bruker, 2002 ▶) T _min = 0.786, T _max = 0.940
10935 measured reflections
4046 independent reflections
3594 reflections with I > 2σ(I)
R _int = 0.029

Refinement

R[F ² > 2σ(F ²)] = 0.056
wR(F ²) = 0.133
S = 1.12
4046 reflections
259 parameters
12 restraints
H-atom parameters constrained
Δρ_max = 1.91 e Å⁻³
Δρ_min = −1.06 e Å⁻³

Data collection: SMART (Bruker, 2002 ▶); cell refinement: SAINT (Bruker, 2003 ▶); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: X-SEED (Atwood & Barbour, 2003 ▶; Barbour, 2001 ▶); software used to prepare material for publication: X-SEED.

Supplementary Material

Crystal structure: contains datablocks I, global. DOI: 10.1107/S1600536809004176/lh2768sup1.cif

e-65-0m265-sup1.cif^{(23KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536809004176/lh2768Isup2.hkl

e-65-0m265-Isup2.hkl^{(198.4KB, hkl)}

Additional supplementary materials: crystallographic information; 3D view; checkCIF report

Table 1. Selected geometric parameters (Å, °).

Ag1—N13	2.130 (4)
Ag1—N23	2.127 (4)

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N13—Ag1—N23

171.84 (17)

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Table 2. Hydrogen-bond geometry (Å, °).

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
N12—H2⋯O1	0.88	1.99	2.851 (6)	165
N12—H1⋯O2ⁱⁱ	0.88	2.07	2.889 (6)	155
N22—H3⋯O1	0.88	2.12	2.959 (7)	158
N22—H4⋯O1ⁱⁱⁱ	0.88	2.11	2.955 (6)	162

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Symmetry codes: (ii) Inline graphic ; (iii) .

Acknowledgments

We thank the National Research Foundation (NRF) of South Africa for financial support.

supplementary crystallographic information

Comment

The cation in the title compound (I) (Fig. 1) is crystallographically independent and consists of two benzothiazol-2-amine ligands coordinating to an Ag^I ion with their thiazole imine nitrogen atoms, thus furnishing an essentially linear geometry around the metal. This is in contrast to a postulation of amino-N coordination by Tewari et al. (1991) which was based on infrared evidence. However, hydrogen bonding may have interfered in the assignment of bands. Their conclusions that nitrate is not bonded to silver and the presence of Ag···S contacts have now been verified for the structure of (I).

The nitrate counter-anion in (I) does not interact with the metal which is reflected in the close to linear N—Ag—N angle of 171.84 (17)°. Similar molecular structures wherein the Ag^I ion is coordinated to two thiazole imine nitrogen atoms and interacts with nitrate, have markedly bent angles of 143.2 (2) and 146.1 (2)° (Fitchett & Steel, 2000), 136.05 (17) and 130.78 (15)° (Zou et al., 2004). Perchlorate shows the same effect with an angle of 144.3 (6)° (Murthy & Murthy, 1976). Essentially linear angles of 173.5 (2), 176.1 (2) and 176.8 (2)° are, however, observed in a trinuclear silver complex (Hiraoka et al., 2003) even though trifluoromethanesulfonate or methanol additionally coordinate to the silver atoms. The Ag—N bond lengths of 2.148 (6)–2.188 (6) Å in this complex are comparable to (I) [2.130 (4) and 2.127 (4) Å], as are the appropriate bond distances in the undisturbed (i.e. the Ag centre is only coordinated by thiazole ligands and the anion does not form part of the coordination sphere) silver perchlorate complexes of bis(benzothiazol-2-ylsulfanyl)methane and 1,4-bis(benzothiazol-2-ylsulfanyl)butane reported by Zou et al. (2004) [2.136 (4) and 2.147 (4) Å in the former and 2.136 (5) Å in the latter complex].

The planes of the two 1,3-benzothiazole groups in (I) lie at an angle of 5.9 (3)° which prevents crowding between H19 and H29 that would otherwise ensue in a flat cation. A short contact between Ag1 and S11ⁱ [3.2261 (15) Å, symmetry code: (i) = x, y + 1, z] can be observed which is shorter than the sum of the van der Waals radii of the concerned atoms. Such Ag···S interactions involving thiazole rings have been observed before with distances of 3.306 Å (Ellsworth et al., 2006), 3.336 Å (Fackler Jr et al., 1992), 3.204 Å (Manzoni de Oliveira et al., 2007) and 3.543 Å (Zou et al., 2004); except for the longer distance in the last example they are comparable to (I).

The nitrate counteranion plays a crucial role in governing the crystal structure of (I). The amino groups of the cations engage in hydrogen bonds to the nitrate anion and form polar one-dimensional hydrogen bonding domains ordered around the crystallographical 2₁ screw axes. The apolar 1,3-benzothiazole "ends" of different columns face each other as well as the co-crystallized acetone solvent molecules (Fig. 2). The hydrogen bonding network (Fig. 1) emanates from the two amino groups of the cation which chelate O1 of the nitrate anion as well as hydrogen bonding to two other nitrates, one from the same side of the chain (via O2, related by a translation in b) and one from the other side (via O1, related by a 2₁ screw operation). O1 accepts three hydrogen bonds and O2 is involved in a single hydrogen bond. O3 does not exhibit hydrogen bonding which might be a cause of its larger thermal ellipsoid due to less restriction in movement.

The only possible π···π-interaction between the heteroaromatic rings is found in the 1,3-benzothiazole containing S11 and its counterpart generated by a centre of inversion [symmetry code: (v) = –x+2, –y+1, –z] with centroid–centroid distances of 3.89 Å.

The acetone solvent is highly disordered and occupies two sites in a 0.56:0.44 ratio. The carbonyl groups roughly point in opposite directions. Additional electron density peaks around the solvent as well as very high U_eq values suggest a high mobility of the acetone molecule.

Experimental

The formation of crystalline (I) occurred during the reaction of [Au(NO₃)(PPh₃)] (0.20 g, 0.38 mmol) with benzothiazol-2-amine (57 mg, 0.38 mmol) in acetone solution (20 ml). It could be traced to the utilization of AgNO₃ and [AuCl(PPh₃)] in the preceding preparation of the gold reagent.