Bis[2-(thio­phen-2-yl)quinoxaline-κN⁴]silver(I) tetra­fluoridoborate

In the title compound, [Ag(C₁₂H₈N₂S)₂]BF₄, the two-coordinate Ag^I ion lies on a crystallographic inversion center and is linearly bonded to the N-donor atoms of two separate quinoxaline ligands. The thio­phenyl ring of the ligand is nearly coplanar with the quinoxaline ring system [dihedral angle = 9.15 (13)°]. In the crystal, the complex mol­ecules pack in layers parallel to (-102) and form weak π–π ring stacking inter­actions [minimum ring centroid separation = 3.7054 (17) Å]. The tetra­fluoridoroborate anion is equally disordered about an inversion center.

Related literature

For the synthesis of the title compound, see: Bhogala et al. (2003). For the structure of a similar compound, see: Wang (2012).

Experimental

Crystal data

• [Ag(C₁₂H₈N₂S)₂]BF₄

• M_r = 619.21

• Monoclinic, C 2/c

• a = 14.1249 (19) Å

• b = 13.1972 (16) Å

• c = 13.739 (2) Å

• β = 102.991 (15)°

• V = 2495.5 (6) ų

• Z = 4

• Mo Kα radiation

• μ = 1.03 mm⁻¹

• T = 293 K

• 0.32 × 0.22 × 0.17 mm

Data collection

• Oxford Diffraction Xcalibur Sapphire3 CCD diffractometer

• Absorption correction: multi-scan (CrysAlis PRO; Oxford Diffraction, 2009) T_min = 0.657, T_max = 1.000

• 30081 measured reflections

• 4624 independent reflections

• 2670 reflections with I > 2σ(I)

• R_int = 0.045

Refinement

• R[F² > 2σ(F²)] = 0.054

• wR(F²) = 0.204

• S = 0.93

• 4624 reflections

• 187 parameters

• 55 restraints

• H-atom parameters constrained

• Δρ_max = 0.68 e Å⁻³

• Δρ_min = −0.51 e Å⁻³

Data collection: CrysAlis CCD (Oxford Diffraction, 2009); cell refinement: CrysAlis RED (Oxford Diffraction, 2009); data reduction: CrysAlis RED; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: PLATON (Spek, 2009); software used to prepare material for publication: SHELXTL (Sheldrick, 2008).

Supporting information

S1. Comment

In the title compound, [Ag(C₁₂H₈N₂S)₂] BF₄, the Ag⁺ lies on a crystallographic inversion center and is linearly bonded to the N donor atoms of two separate quinoxaline ligands [Ag—N, 2.166 (2) Å] (Fig. 1). The thiophenyl substituent ring of the ligand is nearly coplanar with the quinoxaline ring [dihedral angle = 9.15(0.13)°]. All bond lengths and angles fall within the typical ranges found in similar complexes (Wang, 2012). In the crystal, the complex molecules pack in layers and give weak π–π ring stacking interactions [minimum ring centroid separation = 3.7054 (17) Å]. The tetrafluoroborate anion is 50% disordered about an inversion center.

Related literature

For the synthesis of the title compound, see: Bhogala et al. (2003). For the structure of a similar compound, see: Wang (2012).

S2. Experimental

In a 50 mL beaker, 0.471 mmol of 2-(2-thiophenyl)quinoxaline (100 mg) was added to a 20 mL of near boiling absolute ethanol. In a seperate 50 mL beaker, 0.236 mmol of AgBF₄ (39 mg) was added to 15 mL of near boiling absolute ethanol. The two solutions were combined then pipetted into several test tubes placed inside amber vials. Over the course of days, small colourless block-shaped crystals had formed.

S3. Refinement

Hydrogen atoms were placed in calculated positions with a C—H distance of 0.93 Å and were included in the refinement in a riding motion approximation with U_iso = 1.2U_eq of the carrier atom. Difference maps indicated that the tetrafluoridoroborate atom was disordered about an inversion center in the lattice. The disorder was treated by the use of several similarity restraints.

Computing details

Data collection: CrysAlis CCD (Oxford Diffraction, 2009); cell refinement: CrysAlis RED (Oxford Diffraction, 2009); data reduction: CrysAlis RED (Oxford Diffraction, 2009); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: PLATON (Spek, 2009); software used to prepare material for publication: SHELXTL (Sheldrick, 2008).

Figures

Fig. 1. A view of the title compound (Spek, 2009). Displacement ellipsoids are drawn at the 50% probability level. The disordered tetrafluoridoroborate anion is omitted for clarity. For symmetry code (i): -x+5/2, -y+1/2, -z+1.

Bis[2-(thiophen-2-yl)quinoxaline-κN⁴]silver(I) tetrafluoridoborate

Crystal data

[Ag(C12H8N2S)2]BF4	F(000) = 1232
Mr = 619.21	Dx = 1.648 Mg m^−3
Monoclinic, C2/c	Melting point: 395 K
Hall symbol: -C 2yc	Mo Kα radiation, λ = 0.71073 Å
a = 14.1249 (19) Å	Cell parameters from 7201 reflections
b = 13.1972 (16) Å	θ = 4.3–33.4°
c = 13.739 (2) Å	µ = 1.03 mm^−1
β = 102.991 (15)°	T = 293 K
V = 2495.5 (6) Å^3	Plate, white
Z = 4	0.32 × 0.22 × 0.17 mm

Data collection

Oxford Diffraction Xcalibur Sapphire3 CCD diffractometer	4624 independent reflections
Radiation source: fine-focus sealed tube	2670 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.045
Detector resolution: 16.1790 pixels mm^-1	θmax = 33.4°, θmin = 4.3°
ω scans	h = −21→21
Absorption correction: multi-scan (CrysAlis PRO; Oxford Diffraction, 2009)	k = −20→20
Tmin = 0.657, Tmax = 1.000	l = −21→20
30081 measured reflections

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)] = 0.054	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.204	H-atom parameters constrained
S = 0.93	w = 1/[σ^2(Fo^2) + (0.1425P)^2] where P = (Fo^2 + 2Fc^2)/3
4624 reflections	(Δ/σ)max < 0.001
187 parameters	Δρmax = 0.68 e Å^−3
55 restraints	Δρmin = −0.51 e Å^−3

Special details

Experimental. Hydrogen atoms were included in calculated positions with a C—H distance of 0.93 Å and were included in the refinement in a riding motion approximation with U_iso = 1.2U_eq of the carrier atom.

Geometry. All e.s.d.'s (except the e.s.d. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell e.s.d.'s are taken into account individually in the estimation of e.s.d.'s in distances, angles and torsion angles; correlations between e.s.d.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell e.s.d.'s is used for estimating e.s.d.'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 > σ(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	Occ. (<1)
Ag1	1.2500	0.2500	0.5000	0.0834 (2)
N1	1.11733 (17)	0.16642 (18)	0.44213 (18)	0.0522 (5)
C1	1.0346 (2)	0.2103 (2)	0.4009 (2)	0.0519 (6)
H1	1.0308	0.2806	0.4034	0.062*
C8	0.95133 (18)	0.15564 (19)	0.35281 (18)	0.0456 (5)
N2	0.95235 (14)	0.05545 (16)	0.34896 (15)	0.0439 (4)
C7	1.03648 (17)	0.00867 (19)	0.39162 (17)	0.0423 (5)
C2	1.12040 (17)	0.0612 (2)	0.43877 (18)	0.0457 (5)
C3	1.2080 (2)	0.0087 (3)	0.4793 (2)	0.0599 (7)
H3	1.2637	0.0441	0.5099	0.072*
C4	1.2094 (2)	−0.0938 (3)	0.4727 (3)	0.0680 (8)
H4	1.2666	−0.1288	0.4990	0.082*
C5	1.1263 (3)	−0.1472 (2)	0.4270 (3)	0.0661 (8)
H5	1.1289	−0.2175	0.4234	0.079*
C6	1.0418 (2)	−0.0988 (2)	0.3877 (2)	0.0527 (6)
H6	0.9870	−0.1360	0.3581	0.063*
S1	0.76065 (6)	0.13484 (8)	0.25355 (7)	0.0682 (3)
C9	0.8619 (2)	0.2074 (2)	0.3038 (2)	0.0526 (6)
C10	0.8465 (3)	0.3134 (3)	0.2847 (2)	0.0727 (10)
H10	0.8920	0.3644	0.3053	0.087*
C11	0.7490 (3)	0.3275 (3)	0.2284 (3)	0.0787 (11)
H11	0.7233	0.3909	0.2081	0.094*
C12	0.6976 (3)	0.2410 (3)	0.2073 (3)	0.0757 (11)
H12	0.6336	0.2394	0.1708	0.091*
B1	1.0011 (7)	0.5432 (7)	0.4307 (12)	0.174 (6)	0.50
F1	1.0535 (5)	0.4612 (6)	0.4342 (12)	0.234 (7)	0.50
F2	0.9766 (15)	0.5583 (11)	0.5186 (14)	0.405 (13)	0.50
F3	0.9165 (7)	0.5285 (7)	0.3685 (14)	0.331 (10)	0.50
F4	1.0358 (6)	0.6261 (5)	0.4077 (10)	0.244 (7)	0.50

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Ag1	0.0568 (2)	0.0772 (3)	0.1093 (4)	−0.03177 (17)	0.0040 (2)	−0.01481 (19)
N1	0.0466 (11)	0.0521 (12)	0.0570 (13)	−0.0126 (9)	0.0097 (9)	−0.0046 (9)
C1	0.0569 (15)	0.0423 (12)	0.0570 (15)	−0.0105 (11)	0.0137 (12)	−0.0031 (11)
C8	0.0446 (11)	0.0505 (13)	0.0422 (12)	−0.0028 (10)	0.0109 (9)	−0.0012 (10)
N2	0.0370 (9)	0.0493 (11)	0.0444 (11)	−0.0053 (8)	0.0070 (8)	−0.0035 (8)
C7	0.0390 (10)	0.0458 (12)	0.0432 (12)	−0.0061 (9)	0.0112 (9)	−0.0023 (9)
C2	0.0362 (10)	0.0539 (13)	0.0460 (12)	−0.0082 (9)	0.0073 (9)	0.0011 (10)
C3	0.0417 (13)	0.0758 (19)	0.0595 (16)	−0.0039 (12)	0.0059 (11)	0.0041 (14)
C4	0.0509 (16)	0.081 (2)	0.0702 (19)	0.0120 (15)	0.0093 (14)	0.0139 (16)
C5	0.072 (2)	0.0529 (15)	0.075 (2)	0.0122 (14)	0.0215 (17)	0.0108 (14)
C6	0.0554 (14)	0.0446 (13)	0.0563 (15)	−0.0060 (11)	0.0089 (12)	0.0045 (11)
S1	0.0499 (4)	0.0782 (6)	0.0718 (5)	0.0075 (3)	0.0036 (3)	0.0082 (4)
C9	0.0533 (14)	0.0571 (15)	0.0479 (14)	0.0086 (12)	0.0124 (11)	−0.0011 (12)
C10	0.079 (2)	0.082 (2)	0.0557 (17)	0.0280 (19)	0.0122 (16)	−0.0003 (15)
C11	0.085 (2)	0.076 (2)	0.075 (2)	0.032 (2)	0.0171 (19)	0.0093 (18)
C12	0.066 (2)	0.087 (3)	0.071 (2)	0.0307 (18)	0.0072 (17)	0.0093 (16)
B1	0.057 (5)	0.087 (6)	0.361 (17)	−0.015 (4)	0.015 (8)	−0.096 (9)
F1	0.063 (4)	0.091 (5)	0.53 (2)	−0.003 (3)	0.017 (7)	−0.064 (8)
F2	0.66 (4)	0.145 (10)	0.48 (2)	−0.088 (16)	0.29 (2)	−0.150 (14)
F3	0.130 (7)	0.121 (7)	0.64 (3)	−0.002 (5)	−0.133 (11)	−0.059 (11)
F4	0.125 (6)	0.077 (4)	0.55 (2)	−0.037 (4)	0.123 (10)	−0.048 (7)

Geometric parameters (Å, º)

Ag1—N1	2.166 (2)	C5—C6	1.355 (4)
Ag1—N1^i	2.166 (2)	C5—H5	0.9300
N1—C1	1.313 (4)	C6—H6	0.9300
N1—C2	1.391 (3)	S1—C12	1.705 (3)
C1—C8	1.411 (4)	S1—C9	1.731 (3)
C1—H1	0.9300	C9—C10	1.432 (5)
C8—N2	1.323 (3)	C10—C11	1.432 (6)
C8—C9	1.460 (4)	C10—H10	0.9300
N2—C7	1.350 (3)	C11—C12	1.349 (6)
C7—C2	1.400 (3)	C11—H11	0.9300
C7—C6	1.421 (4)	C12—H12	0.9300
C2—C3	1.418 (4)	B1—F4	1.267 (11)
C3—C4	1.357 (5)	B1—F1	1.307 (11)
C3—H3	0.9300	B1—F3	1.317 (11)
C4—C5	1.391 (5)	B1—F2	1.343 (13)
C4—H4	0.9300
N1—Ag1—N1^i	179.998 (2)	C6—C5—H5	119.4
C1—N1—C2	117.2 (2)	C4—C5—H5	119.4
C1—N1—Ag1	123.11 (18)	C5—C6—C7	120.3 (3)
C2—N1—Ag1	119.34 (18)	C5—C6—H6	119.8
N1—C1—C8	122.9 (3)	C7—C6—H6	119.8
N1—C1—H1	118.5	C12—S1—C9	90.6 (2)
C8—C1—H1	118.5	C10—C9—C8	128.5 (3)
N2—C8—C1	120.9 (2)	C10—C9—S1	112.9 (2)
N2—C8—C9	117.7 (2)	C8—C9—S1	118.5 (2)
C1—C8—C9	121.4 (2)	C9—C10—C11	108.3 (4)
C8—N2—C7	117.1 (2)	C9—C10—H10	125.8
N2—C7—C2	123.1 (2)	C11—C10—H10	125.8
N2—C7—C6	119.3 (2)	C12—C11—C10	114.4 (4)
C2—C7—C6	117.7 (2)	C12—C11—H11	122.8
N1—C2—C7	118.7 (2)	C10—C11—H11	122.8
N1—C2—C3	120.3 (2)	C11—C12—S1	113.8 (3)
C7—C2—C3	120.9 (3)	C11—C12—H12	123.1
C4—C3—C2	119.0 (3)	S1—C12—H12	123.1
C4—C3—H3	120.5	F4—B1—F1	118.4 (9)
C2—C3—H3	120.5	F4—B1—F3	108.1 (11)
C3—C4—C5	120.8 (3)	F1—B1—F3	109.0 (9)
C3—C4—H4	119.6	F4—B1—F2	106.8 (10)
C5—C4—H4	119.6	F1—B1—F2	110.4 (12)
C6—C5—C4	121.3 (3)	F3—B1—F2	103.0 (10)

Symmetry code: (i) −x+5/2, −y+1/2, −z+1.