Aqua­bis­[2,5-bis­(pyridin-2-yl)-1,3,4-thia­diazole-κ2 N 2,N 3](trifluoro­methane­sulfonato-κO)copper(II) trifluoro­methane­sulfonate

Fouad Bentiss; Moha Outirite; Michel Lagrenée; Mohamed Saadi; Lahcen El Ammari

doi:10.1107/S1600536812008732

. 2012 Mar 3;68(Pt 4):m360–m361. doi: 10.1107/S1600536812008732

Aquabis[2,5-bis(pyridin-2-yl)-1,3,4-thiadiazole-κ² N ²,N ³](trifluoromethanesulfonato-κO)copper(II) trifluoromethanesulfonate

Fouad Bentiss ^a,^*, Moha Outirite ^b, Michel Lagrenée ^b,^c, Mohamed Saadi ^d, Lahcen El Ammari ^d

PMCID: PMC3343784 PMID: 22589758

Abstract

2,5-Bis(pyridin-2-yl)-1,3,4-thiadiazole (denoted L) has been found to act as a bidentate ligand in the monomeric title complex, [Cu(CF₃O₃S)(C₁₂H₈N₄S)₂(H₂O)](CF₃O₃S). The complex shows a distorted octahedrally coordinated copper(II) cation which is linked to two thiadiazole ligands, one water molecule and one trifluoromethanesulfonate anion. The second trifluoromethanesulfonate anion does not coordinate the copper(II) cation. Each thiadiazole ligand uses one pyridyl and one thiadiazole N atom for the coordination of copper. The N atom of the second non-coordinating pyridyl substituent is found on the same side of the 1,3,4-thiadiazole ring as the S atom. The trifluoromethanesulfonate ions are involved in a three-dimensional network of O—H⋯O hydrogen bonds. C—H⋯N interactions also occur.

Related literature

For the synthesis of the ligand, see: Lebrini et al. (2005 ▶). For background to compounds with the same ligand but other metals and other counter-anions, see: Bentiss et al. (2002 ▶, 2004 ▶, 2011a ▶,b ▶); Keij et al. (1984 ▶); Zheng et al. (2006 ▶).

Experimental

Crystal data

[Cu(CF₃O₃S)(C₁₂H₈N₄S)₂(H₂O)](CF₃O₃S)
M _r = 860.26
Triclinic,
a = 8.469 (3) Å
b = 11.116 (3) Å
c = 18.834 (6) Å
α = 92.111 (14)°
β = 90.823 (14)°
γ = 107.352 (14)°
V = 1690.6 (9) Å³
Z = 2
Mo Kα radiation
μ = 0.98 mm⁻¹
T = 100 K
0.39 × 0.30 × 0.17 mm

Data collection

Bruker APEXII CCD diffractometer
Absorption correction: multi-scan (SADABS; Sheldrick, 1995 ▶) T _min = 0.879, T _max = 1.000
12380 measured reflections
6517 independent reflections
5421 reflections with I > 2σ(I)
R _int = 0.031

Refinement

R[F ² > 2σ(F ²)] = 0.041
wR(F ²) = 0.099
S = 1.03
6517 reflections
469 parameters
H-atom parameters constrained
Δρ_max = 1.39 e Å⁻³
Δρ_min = −0.41 e Å⁻³

Data collection: APEX2 (Bruker, 2005 ▶); cell refinement: SAINT (Bruker, 2005 ▶); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: ORTEP-3 for Windows (Farrugia, 1997 ▶) and ORTEPIII (Burnett & Johnson, 1996 ▶); software used to prepare material for publication: WinGX (Farrugia, 1999 ▶).

Supplementary Material

Crystal structure: contains datablock(s) I, global. DOI: 10.1107/S1600536812008732/im2358sup1.cif

e-68-0m360-sup1.cif^{(39KB, cif)}

Structure factors: contains datablock(s) I. DOI: 10.1107/S1600536812008732/im2358Isup2.hkl

e-68-0m360-Isup2.hkl^{(312.5KB, hkl)}

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

Table 1. Hydrogen-bond geometry (Å, °).

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
O1—H1W⋯O6	0.78	1.95	2.721 (3)	169
O1—H2W⋯O2ⁱ	0.80	1.94	2.732 (3)	167
C6—H6⋯N7	0.95	2.33	3.146 (4)	143
C18—H18⋯N3	0.95	2.36	3.174 (4)	143

Open in a new tab

Symmetry code: (i) Inline graphic .

supplementary crystallographic information

Comment

With ligands containing five-membered nitrogen heterocycles, 3 d transition metals such as Ni(II) and Cu(II) have a tendency to form mono- or polynuclear species (Keij et al., 1984). Dinuclear species are of interest due to the potential magnetic coupling of unpaired 3 d electrons via bridging nitrogen containing ligands. Ligands related to 1,2-diazoles with o-pyridine substitution at position 3 and 5, such as 2,5-bis(2-pyridyl)-1,3,4-oxadiazole and thiadiazole, have been of interest for such applications. Indeed, 2,5-bis(2-pyridyl)-1,3,4-thiadiazole can be used in transition metal complexes in association with additional anionic ligands. In the resulting di- and mononuclear complexes, a variety of coordination modes have been observed, of which the dinuclear (N`N``, N2, N``) bridging, the dinuclear (N`N``, N2, N``)₂ double bridging and the mononuclear (N`,N`)₂ coordination mode are the most common and most important ones (Scheme 1). The latter mode in octahedral complexes is exclusively observed in trans configuration. For the dimeric mode, we have previously reported the synthesis and characterization of the corresponding complexes of Cu(II) and Ni(II) with the 2,5-bis(2-pyridyl)-thiadiazole derivative (bptd) (Bentiss et al., 2004). There are no other reports of the dimeric structures of solid state complexes of this neutral ligand (bptd).

The structures of monomeric complexes of the neutral 2,5-bis(2-pyridyl)-1,3,4-thiadiazole derivative with divalent Zn (chloride and perchlorate), Co (nitrate, perchlorate and tetrafluoborate), Ni (perchlorate and tetrafluoborate), and Cu (nitrate, perchlorate) have been previously reported (Bentiss et al., 2002; Bentiss et al., 2011a; Zheng et al., 2006; Bentiss et al., 2011b). We report here the synthesis and the single-crystal structure of the new monomeric complex formed by 2,5-bis(2-pyridyl)-1,3,4-thiadiazole with copper trifluoromethanesulfonate.

In the new monomeric title complex, the Cu atom is no longer situated on a center of symmetry: its octahedral coordination sphere is built from two crystallographically independent molecules L and two O atoms of different chemical entities: O1 is from a water molecule with Cu1—O1 = 2.259 (2) Å and O4 from one trifluoromethanesulfonate anion with a very long distance Cu1—O4 = 2.540 (3)Å (Fig.1). The axial distortion of the octahedron corresponds to the Jahn-Teller effect typical for Cu²⁺. While N—Cu—O1 angles range from 88.18 (9)° (N2—Cu—O1) to 94.74 (9)° (N1—Cu—O1), keeping O1 at the axial position on one side of the distorted equatorial plane, the bonded O4 trifluoromethanesulfonate end is located in the opposite axial position, with N—Cu—O4 angles ranging from 85.90 (9)° (N5—Cu—O4) to 89.47 (9)° (N6—Cu—O4).

In this monomeric complex, a completely different ligand configuration is observed compared to our recently reported Co and Ni monomeric complexes of bptd. In both L ligands the non-complexed pyridyl rings are still coplanar with the central thiadiazole heterocycle, while both complexed pyridyl rings are no longer coplanar with the central thiadiazole. In one of the ligands L, topped with the CF₃ end of the Cu bound trifluoromethanesulfonate, a small interplanar angle of 3.7 (2) ° of the pyridyl moiety with the thiadiazole ring is observed. On the other hand, in the second ligand this twist is much more pronounced as indicated by an interplanar angle of 12.8 (2)° of the non-coordinated pyridine witrh respect to the remaining planar part of L. This difference cannot be related to any hydrogen bonding interaction with its neighbouring unbound trifluoromethanesulfonate. The trifluoromethanesulfonate ions are involved in an infinite three-dimensional network of O–H···O hydrogen bonds (see Fig.2).

Experimental

2,5-Bis(2-pyridyl)-1,3,4-thiadiazole ligand (noted L) was synthesized as described previously (Lebrini et al., 2005). Cu(O₃SCF₃)₂ (1.5 mmol, 0.54 g) in 8 ml of water was added to (0.42 mmol, 0.1 g) of L (bptd ligand) dissolved in 8 ml of ethanol. The solution was filtered and after 24 h, the blue compound crystallized at room temperature. Yield: 63%. Crystals were washed with water and dried under vacuum. Anal. Calc. for C₂₅H₁₈CuF₆N₈O₇S₄: C, 36.27; H, 2.09; N, 13.02; S, 14.91; F, 13.25%. Found: C, 36.32; H, 2.17; N, 12.98; S, 14.88; F, 13.30%.