trans-Diaqua­bis­[2,5-bis­(pyridin-2-yl)-1,3,4-thia­diazole]nickel(II) bis­(tetra­fluoridoborate)

The bidentate 1,3,4-thia­diazole ligand, namely, 2,5-bis­(2-pyrid­yl)-1,3,4-thia­diazole (denoted L), untested as a polydentate ligand, has been found to form the monomeric title complex, [Ni(C₁₂H₈N₄S)₂(H₂O)₂](BF₄)₂. The complex shows an octa­hedral environment of the nickel cation in which the Ni²⁺ ion is located on a center of symmetry, linked to two ligands and two water molecules. In this 1:2 complex (one metal for two organic ligands) each thia­diazole ligand uses one pyridyl and one thia­diazole N atom for chelate binding. In the second pyridyl substituent, the N atom is oriented towards the same direction as the S atom of the 1,3,4-thiadiazole ring. The mean plane of the thia­diazole and pyridyl rings linked to the nickel cation forms a dihedral angle with the other pyridine ring of 18.63 (8)°. The tetra­fluorido­borate ions can be regarded as free anions in the crystal lattice. Nevertheless, they are involved in an infinite two-dimensional network parallel to (01) through O—H...F hydrogen bonds.

Key indicators

• Single-crystal X-ray study
• T = 100 K
• Mean [sigma](C-C) = 0.003 Å
• R factor = 0.029
• wR factor = 0.073
• Data-to-parameter ratio = 14.6

checkCIF/PLATON results

No syntax errors found



Alert level C
PLAT244_ALERT_4_C Low   'Solvent' Ueq as Compared to Neighbors of          B1
PLAT910_ALERT_3_C Missing # of FCF Reflections Below Th(Min) .....          2

Alert level G
PLAT005_ALERT_5_G No _iucr_refine_instructions_details in CIF ....          ?
PLAT128_ALERT_4_G Alternate Setting of Space-group P21/c   .......      P21/n
PLAT232_ALERT_2_G Hirshfeld Test Diff (M-X)  Ni1    --  N1      ..        5.3 su

   0 ALERT level A = Most likely a serious problem - resolve or explain
   0 ALERT level B = A potentially serious problem, consider carefully
   2 ALERT level C = Check. Ensure it is not caused by an omission or oversight
   3 ALERT level G = General information/check it is not something unexpected

   0 ALERT type 1 CIF construction/syntax error, inconsistent or missing data
   1 ALERT type 2 Indicator that the structure model may be wrong or deficient
   1 ALERT type 3 Indicator that the structure quality may be low
   2 ALERT type 4 Improvement, methodology, query or suggestion
   1 ALERT type 5 Informative message, check

---

S1. Comment

With ligands containing a five azide ring, 3 d transition metals such as Ni^II and Cu^II have a tendency to form mono or polynuclear species (Keij et al., 1984). The dinuclear species are of interest due to their potential magnetic coupling. The unpaired 3 d electrons being potentially coupled via the intermediary of the bridging azide ligands. The ligands related to the 1,2-diazoles with o-pyridine substitution at the 3 and 5 positions, 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 as a molecular architect with transition metals in association with anionic Ni-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 monoclear (N`,N`)2 coordination mode are the most common and the most important ones (Scheme 1), the latter mode, the trans type is exclusively observed for featuring octahedral complexes.

The structures of monomeric complexes of the neutral 2,5-bis(2-pyridyl)-1, 3,4-thiadiazole derivative with divalent Zn (tetrachloride and perchlorate), Co (nitrate, perchlorate and tetrafluoborate), Ni (perchlorate), and Cu (nitrate, perchlorate) have been previously reported (Bentiss et al., 2002; Bentiss et al.,2004; Zheng et al. 2006; Bentiss et al., 2011). We report here the synthesis and the single-crystal structure of the new monomeric complexe formed by 2,5-bis(2-pyridyl)-1,3,4-thiadiazole with nickel tetrafluoroborate as counter ions.

The complexe shows an almost regular octahedral environment of the nickel cation in wich Ni²⁺ is located at a center of symmetry, and linked to two ligand and two water molecules as shown in Fig.1. As a matter of fact, the nickel coordination sphere is achieved by interaction with the nitrogen atom of a single pyridyl ring and with the near nitrogen of the azide group with Ni—N distances in the range of 2.052 (2)—2.132 (2) Å. Moreover, the water molecules are found in axial positions at distances and angles of Ni—O 2.120 (2) Å and all N—Ni—O angles being close to 90 °.

The dihedral angle between the thiadiazole and the pyridyl rings linked to the nickel cation is in the range of 4.16 (9)°. The mean plane of the two preceding cycles forms a dihedral angle with the (N4—C8—C9—C10—C11—C12) other pyridine ring of 18.63 (8)°. The counter ion, BF₄^- is involved in an infinite two-dimensional network of O—H···F hydrogen bonds parallel to the (-1 0 1) plane (Table 1, Fig.1).

Related literature

For Ni^II and Cu^II complexes containing a five azide ring, see: Keij et al. (1984). For background to similar structures, see: Bentiss et al. (2002, 2004, 2011); Zheng et al. (2006). For an improved synthesis of the ligand, see: Lebrini et al. (2005).

S2. Experimental

2,5-Bis(2-pyridyl)-1,3,4-thiadiazole ligand (noted L) was synthesized as described previously by Lebrini et al., 2005. Ni(BF₄)₂6H₂O (1.5 mmol, 0.51 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 colorless compound crystallized at room temperature. Crystals were washed with water and dried under vacuum. Yield: 51%. Anal. Calc. for C₂₄H₂₀B₂F₈N₈NiO₂S₂: C, 38.44; H, 2.67; N, 14.95; S, 8.56; F, 20.29%. Found: C, 38.52; H, 2.75; N, 14.90; S, 8.53; F, 20.27%.

S3. Refinement

H atoms attached to carbon were located in a difference map but introduced in calculated position and treated as riding with C—H = 0.95 Å for the aromatic CH, with U_iso(H) = 1.2 U_eq (aromatic). The O-bound H atom were initially located in a difference map and refined with O—H distance restraints of 0.86 (1). In the the last cycles of refinement, they are treated as riding on their parent O atoms with U_iso(H) set to 1.2U_eq(O).

Computing details

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

Figures

Fig. 1. Plot of the crystal structure showing the molecules linked to the nickel cation and the counter ions, BF4^-, with the atom-labelling scheme. Displacement ellipsoids are drawn at the 50% probability level. H atoms are represented as small circles. Hydrogen bonds are shown as dashed lines.

trans-Diaquabis[2,5-bis(pyridin-2-yl)-1,3,4-thiadiazole]nickel(II) bis(tetrafluoridoborate)

Crystal data

[Ni(C12H8N4S)2(H2O)2](BF4)2	F(000) = 756
Mr = 748.93	Dx = 1.610 Mg m^−3
Monoclinic, P21/n	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2yn	Cell parameters from 3120 reflections
a = 10.8164 (15) Å	θ = 2.7–26.3°
b = 11.0126 (13) Å	µ = 0.85 mm^−1
c = 13.2333 (16) Å	T = 100 K
β = 101.455 (6)°	Prism, colourless
V = 1544.9 (3) Å^3	0.26 × 0.21 × 0.13 mm
Z = 2

Data collection

Bruker X8 APEXII CCD area-detector diffractometer	3120 independent reflections
Radiation source: fine-focus sealed tube	2729 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.035
ϕ and ω scans	θmax = 26.3°, θmin = 2.7°
Absorption correction: multi-scan (SADABS; Bruker, 2005)	h = −13→13
Tmin = 0.809, Tmax = 0.898	k = −13→13
28021 measured reflections	l = −16→16

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)] = 0.029	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.073	H-atom parameters constrained
S = 1.05	w = 1/[σ^2(Fo^2) + (0.0302P)^2 + 1.3259P] where P = (Fo^2 + 2Fc^2)/3
3120 reflections	(Δ/σ)max < 0.001
214 parameters	Δρmax = 0.60 e Å^−3
0 restraints	Δρmin = −0.40 e Å^−3

Special details

Geometry. All s.u.'s (except the s.u. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell s.u.'s are taken into account individually in the estimation of s.u.'s in distances, angles and torsion angles; correlations between s.u.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell s.u.'s is used for estimating s.u.'s involving l.s. planes.

Refinement. Refinement of F² against all reflections. The weighted R-factor wR and goodness of fit S are based on F², conventional R-factors R are based on F, with F set to zero for negative F². The threshold expression of F² > 2σ(F²) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F² are statistically about twice as large as those based on F, and R- factors based on all data will be even larger.

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

	x	y	z	Uiso*/Ueq
B1	0.5722 (2)	0.6450 (2)	0.25602 (17)	0.0236 (4)
F1	0.67390 (15)	0.59474 (18)	0.32316 (11)	0.0707 (6)
F2	0.58436 (11)	0.62341 (12)	0.15219 (9)	0.0362 (3)
F3	0.46260 (14)	0.59379 (14)	0.27433 (14)	0.0583 (4)
F4	0.56853 (15)	0.77036 (12)	0.27479 (11)	0.0494 (4)
C1	0.40875 (16)	0.75569 (16)	−0.02295 (14)	0.0202 (4)
C2	0.47768 (16)	1.25248 (17)	0.06948 (13)	0.0200 (4)
C3	0.43547 (18)	1.35965 (17)	0.10676 (14)	0.0236 (4)
H3	0.4806	1.4333	0.1048	0.028*
C4	0.32542 (18)	1.35711 (18)	0.14729 (15)	0.0258 (4)
H4	0.2940	1.4292	0.1726	0.031*
C5	0.26311 (18)	1.24770 (18)	0.14982 (15)	0.0265 (4)
H5	0.1883	1.2433	0.1770	0.032*
C6	0.31231 (18)	1.14360 (18)	0.11167 (15)	0.0248 (4)
H6	0.2696	1.0686	0.1144	0.030*
C7	0.22180 (17)	0.74859 (17)	0.04687 (14)	0.0210 (4)
C8	0.10347 (17)	0.71642 (18)	0.08024 (14)	0.0222 (4)
C9	0.01756 (18)	0.80507 (19)	0.09554 (16)	0.0296 (4)
H9	0.0335	0.8887	0.0859	0.036*
C10	−0.09264 (19)	0.7670 (2)	0.12544 (17)	0.0342 (5)
H10	−0.1541	0.8246	0.1364	0.041*
C11	−0.11154 (19)	0.6445 (2)	0.13902 (16)	0.0329 (5)
H11	−0.1862	0.6166	0.1591	0.040*
C12	−0.0195 (2)	0.5627 (2)	0.12282 (16)	0.0310 (5)
H12	−0.0326	0.4787	0.1334	0.037*
Ni1	0.5000	1.0000	0.0000	0.01936 (10)
N1	0.41765 (14)	1.14452 (14)	0.07112 (12)	0.0218 (3)
N2	0.38061 (14)	0.85992 (14)	0.01661 (12)	0.0210 (3)
N3	0.27253 (14)	0.85652 (14)	0.05732 (12)	0.0226 (3)
N4	0.08724 (15)	0.59655 (15)	0.09286 (13)	0.0260 (4)
O1	0.61598 (13)	0.95553 (13)	0.14395 (11)	0.0307 (3)
H1W	0.6844	0.9932	0.1692	0.037*
H2W	0.6090	0.9007	0.1886	0.037*
S1	0.30384 (4)	0.64191 (4)	−0.01275 (4)	0.02147 (12)

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
B1	0.0194 (10)	0.0233 (11)	0.0268 (11)	0.0023 (8)	0.0017 (8)	0.0008 (9)
F1	0.0620 (10)	0.1029 (14)	0.0388 (8)	0.0561 (10)	−0.0106 (7)	−0.0066 (9)
F2	0.0351 (7)	0.0440 (8)	0.0285 (6)	−0.0059 (6)	0.0039 (5)	−0.0035 (6)
F3	0.0514 (9)	0.0459 (9)	0.0907 (12)	−0.0177 (7)	0.0457 (9)	−0.0236 (8)
F4	0.0759 (10)	0.0240 (7)	0.0503 (8)	−0.0093 (7)	0.0178 (7)	−0.0030 (6)
C1	0.0189 (9)	0.0170 (9)	0.0231 (9)	−0.0021 (7)	0.0004 (7)	0.0028 (7)
C2	0.0188 (9)	0.0196 (9)	0.0203 (8)	−0.0010 (7)	0.0005 (7)	0.0021 (7)
C3	0.0248 (10)	0.0184 (9)	0.0270 (10)	−0.0014 (7)	0.0034 (8)	0.0006 (8)
C4	0.0283 (10)	0.0214 (10)	0.0283 (10)	0.0025 (8)	0.0073 (8)	−0.0018 (8)
C5	0.0248 (10)	0.0258 (10)	0.0302 (10)	−0.0003 (8)	0.0090 (8)	0.0004 (8)
C6	0.0243 (9)	0.0213 (10)	0.0297 (10)	−0.0038 (8)	0.0078 (8)	0.0001 (8)
C7	0.0197 (9)	0.0197 (9)	0.0226 (9)	0.0002 (7)	0.0015 (7)	0.0009 (7)
C8	0.0194 (9)	0.0246 (10)	0.0218 (9)	−0.0032 (8)	0.0020 (7)	−0.0011 (8)
C9	0.0247 (10)	0.0270 (11)	0.0362 (11)	0.0009 (8)	0.0040 (8)	−0.0007 (9)
C10	0.0246 (10)	0.0425 (13)	0.0365 (11)	0.0058 (9)	0.0086 (9)	−0.0034 (10)
C11	0.0244 (10)	0.0476 (14)	0.0295 (10)	−0.0075 (9)	0.0116 (8)	−0.0016 (10)
C12	0.0337 (11)	0.0290 (11)	0.0331 (11)	−0.0092 (9)	0.0131 (9)	0.0009 (9)
Ni1	0.01766 (17)	0.01400 (17)	0.02659 (18)	−0.00261 (13)	0.00479 (13)	−0.00057 (13)
N1	0.0205 (8)	0.0182 (8)	0.0264 (8)	−0.0019 (6)	0.0039 (6)	0.0009 (6)
N2	0.0186 (7)	0.0179 (8)	0.0267 (8)	−0.0013 (6)	0.0048 (6)	0.0000 (6)
N3	0.0193 (8)	0.0208 (8)	0.0282 (8)	−0.0032 (6)	0.0056 (6)	0.0012 (7)
N4	0.0267 (8)	0.0233 (9)	0.0299 (8)	−0.0047 (7)	0.0099 (7)	−0.0014 (7)
O1	0.0270 (7)	0.0276 (8)	0.0337 (8)	−0.0075 (6)	−0.0030 (6)	0.0064 (6)
S1	0.0188 (2)	0.0158 (2)	0.0299 (2)	−0.00252 (17)	0.00479 (18)	0.00033 (18)

Geometric parameters (Å, º)

B1—F3	1.377 (3)	C7—S1	1.7517 (19)
B1—F1	1.385 (3)	C8—N4	1.346 (3)
B1—F4	1.404 (3)	C8—C9	1.390 (3)
B1—F2	1.426 (2)	C9—C10	1.393 (3)
C1—N2	1.322 (2)	C9—H9	0.9500
C1—C2^i	1.482 (2)	C10—C11	1.382 (3)
C1—S1	1.7137 (18)	C10—H10	0.9500
C2—N1	1.357 (2)	C11—C12	1.391 (3)
C2—C3	1.391 (3)	C11—H11	0.9500
C2—C1^i	1.482 (2)	C12—N4	1.345 (2)
C3—C4	1.400 (3)	C12—H12	0.9500
C3—H3	0.9500	Ni1—N2	2.0515 (15)
C4—C5	1.384 (3)	Ni1—N2^i	2.0515 (15)
C4—H4	0.9500	Ni1—O1^i	2.1197 (14)
C5—C6	1.400 (3)	Ni1—O1	2.1197 (14)
C5—H5	0.9500	Ni1—N1^i	2.1320 (16)
C6—N1	1.352 (2)	Ni1—N1	2.1320 (16)
C6—H6	0.9500	N2—N3	1.381 (2)
C7—N3	1.305 (2)	O1—H1W	0.8564
C7—C8	1.478 (2)	O1—H2W	0.8588
F3—B1—F1	108.98 (19)	C9—C10—H10	120.4
F3—B1—F4	108.44 (17)	C10—C11—C12	118.91 (18)
F1—B1—F4	109.02 (18)	C10—C11—H11	120.5
F3—B1—F2	110.41 (17)	C12—C11—H11	120.5
F1—B1—F2	109.73 (17)	N4—C12—C11	123.3 (2)
F4—B1—F2	110.22 (17)	N4—C12—H12	118.4
N2—C1—C2^i	119.49 (16)	C11—C12—H12	118.4
N2—C1—S1	113.30 (13)	N2—Ni1—N2^i	180.00 (9)
C2^i—C1—S1	127.21 (14)	N2—Ni1—O1^i	89.84 (6)
N1—C2—C3	123.10 (16)	N2^i—Ni1—O1^i	90.16 (6)
N1—C2—C1^i	113.09 (16)	N2—Ni1—O1	90.16 (6)
C3—C2—C1^i	123.81 (16)	N2^i—Ni1—O1	89.84 (6)
C2—C3—C4	118.89 (17)	O1^i—Ni1—O1	180.00 (8)
C2—C3—H3	120.6	N2—Ni1—N1^i	79.22 (6)
C4—C3—H3	120.6	N2^i—Ni1—N1^i	100.78 (6)
C5—C4—C3	118.81 (18)	O1^i—Ni1—N1^i	90.02 (6)
C5—C4—H4	120.6	O1—Ni1—N1^i	89.98 (6)
C3—C4—H4	120.6	N2—Ni1—N1	100.78 (6)
C4—C5—C6	118.84 (17)	N2^i—Ni1—N1	79.22 (6)
C4—C5—H5	120.6	O1^i—Ni1—N1	89.98 (6)
C6—C5—H5	120.6	O1—Ni1—N1	90.02 (6)
N1—C6—C5	123.20 (17)	N1^i—Ni1—N1	180.0
N1—C6—H6	118.4	C6—N1—C2	117.16 (16)
C5—C6—H6	118.4	C6—N1—Ni1	128.93 (13)
N3—C7—C8	123.90 (17)	C2—N1—Ni1	113.82 (12)
N3—C7—S1	114.75 (13)	C1—N2—N3	114.22 (15)
C8—C7—S1	121.34 (14)	C1—N2—Ni1	114.28 (12)
N4—C8—C9	124.27 (17)	N3—N2—Ni1	131.42 (12)
N4—C8—C7	114.47 (16)	C7—N3—N2	110.73 (15)
C9—C8—C7	121.26 (17)	C12—N4—C8	116.68 (17)
C8—C9—C10	117.7 (2)	Ni1—O1—H1W	123.4
C8—C9—H9	121.2	Ni1—O1—H2W	131.6
C10—C9—H9	121.2	H1W—O1—H2W	105.0
C11—C10—C9	119.2 (2)	C1—S1—C7	87.00 (9)
C11—C10—H10	120.4
N1—C2—C3—C4	−0.5 (3)	C3—C2—N1—Ni1	176.49 (14)
C1^i—C2—C3—C4	178.72 (17)	C1^i—C2—N1—Ni1	−2.83 (19)
C2—C3—C4—C5	0.7 (3)	C2^i—C1—N2—N3	179.76 (15)
C3—C4—C5—C6	−0.1 (3)	S1—C1—N2—N3	−0.4 (2)
C4—C5—C6—N1	−0.7 (3)	C2^i—C1—N2—Ni1	2.7 (2)
N3—C7—C8—N4	−160.31 (18)	S1—C1—N2—Ni1	−177.46 (8)
S1—C7—C8—N4	20.7 (2)	C8—C7—N3—N2	−178.38 (16)
N3—C7—C8—C9	20.3 (3)	S1—C7—N3—N2	0.6 (2)
S1—C7—C8—C9	−158.62 (15)	C1—N2—N3—C7	−0.1 (2)
N4—C8—C9—C10	−0.3 (3)	Ni1—N2—N3—C7	176.26 (13)
C7—C8—C9—C10	179.01 (18)	C11—C12—N4—C8	1.1 (3)
C8—C9—C10—C11	0.3 (3)	C9—C8—N4—C12	−0.4 (3)
C9—C10—C11—C12	0.3 (3)	C7—C8—N4—C12	−179.74 (17)
C10—C11—C12—N4	−1.0 (3)	N2—C1—S1—C7	0.63 (14)
C5—C6—N1—C2	0.9 (3)	C2^i—C1—S1—C7	−179.58 (17)
C5—C6—N1—Ni1	−175.27 (14)	N3—C7—S1—C1	−0.72 (15)
C3—C2—N1—C6	−0.2 (3)	C8—C7—S1—C1	178.31 (16)
C1^i—C2—N1—C6	−179.56 (16)

Symmetry code: (i) −x+1, −y+2, −z.

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
O1—H1W···F1^ii	0.86	1.88	2.704 (2)	160
O1—H2W···F4	0.86	1.94	2.7880 (19)	171

Symmetry code: (ii) −x+3/2, y+1/2, −z+1/2.