Bis(2,6-dimethyl­pyridine-κN)gold(I) tetra­chloridoaurate(III)

Abstract

In the cation of the title compound, [Au(C₇H₉N)₂][AuCl₄], the Au^I atom is two-coordinated in a linear arrangement by two N atoms from two 2,6-dimethyl­pyridine ligands. In the anion, the Au^III atom has a virtually square-planar coordination geometry. The Au atoms both are located on centers of inversion. The crystal structure involves inter­molecular C—H⋯Cl hydrogen bonds.

Related literature

For related literature, see: Abbate et al. (2000 ▶); Adams & Strähle (1982 ▶); Ahmadi et al. (2008 ▶); Amani et al. (2008 ▶); Bjerne­mose et al. (2004 ▶); Hayoun et al. (2006 ▶); Hojjat Kashani et al. (2008 ▶); Hollis & Lippard (1983 ▶); McInnes et al. (1995 ▶); Yildirim et al. (2008 ▶).

Experimental

Crystal data

• [Au(C₇H₉N)₂][AuCl₄]

• M _r = 750.04

• Monoclinic,

• a = 17.773 (3) Å

• b = 6.8395 (8) Å

• c = 8.3728 (14) Å

• β = 110.929 (12)°

• V = 950.6 (3) ų

• Z = 2

• Mo Kα radiation

• μ = 15.97 mm⁻¹

• T = 298 (2) K

• 0.20 × 0.12 × 0.08 mm

Data collection

• Bruker SMART APEX CCD area-detector diffractometer

• Absorption correction: multi-scan (SADABS; Sheldrick, 1996 ▶) T _min = 0.112, T _max = 0.275

• 5473 measured reflections

• 1384 independent reflections

• 1123 reflections with I > 2σ(I)

• R _int = 0.092

Refinement

• R[F ² > 2σ(F ²)] = 0.044

• wR(F ²) = 0.115

• S = 1.20

• 1384 reflections

• 69 parameters

• H-atom parameters constrained

• Δρ_max = 1.76 e Å⁻³

• Δρ_min = −2.1 e Å⁻³

Data collection: SMART (Bruker, 2007 ▶); cell refinement: SAINT (Bruker, 2007 ▶); data reduction: SAINT; program(s) used to solve structure: SHELXTL (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXTL; molecular graphics: SHELXTL; software used to prepare material for publication: WinGX (Farrugia, 1999 ▶).

Supplementary Material

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

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

Au1—N1	2.030 (8)
Au2—Cl1	2.280 (3)
Au2—Cl2	2.286 (4)

Cl1i—Au2—Cl2	90.05 (14)
Cl1—Au2—Cl2	89.95 (14)

Symmetry code: (i) .

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

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
C3—H3⋯Cl1ii	0.93	2.77	3.572 (14)	145

Symmetry code: (ii) .

supplementary crystallographic information

Comment

Recently, we reported the syntheses and crystal structures of [Au(dmphen)Cl₂][AuCl₄], (II), (Ahmadi et al., 2008), [dmpyH][PtCl₆], (III), (Amani et al., 2008) and [H₂DA18C6][AuCl₄].2H₂O, (IV), (Hojjat Kashani et al., 2008) (dmphen = 4,7-diphenyl-1,10-phenanthroline; dmpyH = 2,6-dimethylpyridinium and H₂DA18C6 = 1,10-diazonia-18-crown-6). Several Au^III complexes with formula [AuCl₂L]X, such as [AuCl₂(bipy)](BF₄), (V), (McInnes et al., 1995), [AuCl₂(bipy)](NO₃), (VI), (Bjernemose et al., 2004), [AuCl₂(bipy)][AuBr₄], (VII), (Hayoun et al., 2006), [AuCl₂(dtbpy)][AuCl₄].CH₃CN, (VIII), (Yildirim et al., 2008) and [AuCl₂(phen)]Cl.H₂O, (IX), (Abbate et al., 2000) (bipy = 2,2'-bipyridine; dtbpy = 4,4'-ditertbutyl-2,2'-bipyridine; phen = 1,10-phenanthroline) have been synthesized and characterized by single-crystal X-ray diffraction methods. Two Au^III complexes with formula [AuCl₂L₂]X, [AuCl₂(py)₂][AuCl₄], (X), and [AuCl₂(py)₂]Cl.H₂O, (XI), (Adams & Strahle, 1982) (py = pyridine) and only one mixed-valence Au^I–Au^III complex, [Au(terpy)Cl]₂[AuCl₂]₃[AuCl₄], (XII), (Hollis & Lippard, 1983) (terpy = 2,2',2''-terpyridine) have been synthesized and characterized by single-crystal X-ray diffraction methods. We report herein the synthesis and crystal structure of the title compound (I).

In the cation of the title compound (Fig. 1), the Au^I atom is two-coordinated in a linear arrangement by two N atoms from two 2,6-dimethylpyridine ligands. In the anion, the Au^III atom has a square-planar coordination geometry. The Au atoms each are located on an inversion center. In the cation, the Au—N bond length (Table 1) is in good agreement with the corresponding values in (X) and (XI) and in the anion, the Au—Cl bond lengths and angles (Table 1) are within a normal range, comparable with those in (II), (VIII) and (XII). In the crystal structure, intermolecular C—H···Cl hydrogen bonds are observed.

Experimental

A solution of 2,6-dimethylpyridine (0.12 g, 1.09 mmol) in methanol (15 ml) was added to a solution of HAuCl₃.3H₂O, (0.37 g, 1.09 mmol) in acetonitrile (15 ml). The resulting yellow solution was stirred for 10 min at 313 K, and then it was left to evaporate slowly at room temperature. After one week, yellow block crystals of (I) were isolated (yield 75.8%, 0.31 g; m. p. 489 K).

Refinement

All H atoms were positioned geometrically and refined as riding atoms, with C—H = 0.93 (aromatic) and 0.96 (methyl) Å and with U_iso(H) = 1.2U_eq(C). The highest residual electron density was found 0.90 Å from atom Au2 and the deepest hole 0.81 Å from atom Au2.

Figures

Fig. 1.

The molecular structure of the title compound. Displacement ellipsoids are drawn at the 40% probability level. [Symmetry code: (i) -x, y, 1 - z.]

Crystal data

[Au(C7H9N)2][AuCl4]	F(000) = 684
Mr = 750.04	Dx = 2.62 Mg m−3
Monoclinic, C2/m	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -C 2y	Cell parameters from 971 reflections
a = 17.773 (3) Å	θ = 2.6–29.2°
b = 6.8395 (8) Å	µ = 15.97 mm−1
c = 8.3728 (14) Å	T = 298 K
β = 110.929 (12)°	Block, yellow
V = 950.6 (3) Å3	0.20 × 0.12 × 0.08 mm
Z = 2

Data collection

Bruker SMART APEX CCD area-detector diffractometer	1123 reflections with I > 2σ(I)
φ and ω scans	Rint = 0.092
Absorption correction: multi-scan (SADABS; Sheldrick, 1996)	θmax = 29.2°, θmin = 2.6°
Tmin = 0.112, Tmax = 0.275	h = −23→24
5473 measured reflections	k = −9→8
1384 independent reflections	l = −11→11

Refinement

Refinement on F2	0 restraints
Least-squares matrix: full	H-atom parameters constrained
R[F2 > 2σ(F2)] = 0.044	w = 1/[σ2(Fo2) + (0.0468P)2 + 5.4887P] where P = (Fo2 + 2Fc2)/3
wR(F2) = 0.115	(Δ/σ)max = 0.004
S = 1.20	Δρmax = 1.76 e Å−3
1384 reflections	Δρmin = −2.1 e Å−3
69 parameters

Special details

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.

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

	x	y	z	Uiso*/Ueq
Au1	0	0.5	0.5	0.04157 (18)
Au2	0	0	0.5	0.0484 (2)
Cl1	0.13598 (17)	0	0.6416 (5)	0.0656 (9)
Cl2	0.0196 (2)	0	0.2445 (5)	0.0726 (10)
N1	0.1180 (5)	0.5	0.6531 (12)	0.044 (2)
C1	0.0754 (8)	0.5	0.8993 (16)	0.068 (4)
H1A	0.0803	0.6146	0.9684	0.081*
H1B	0.0238	0.5	0.8084	0.081*
C2	0.1398 (7)	0.5	0.8262 (15)	0.054 (3)
C3	0.2206 (8)	0.5	0.9317 (17)	0.071 (4)
H3	0.2353	0.5	1.05	0.085*
C4	0.2774 (8)	0.5	0.859 (2)	0.079 (5)
H4	0.3315	0.5	0.9288	0.095*
C5	0.2568 (8)	0.5	0.684 (2)	0.065 (3)
H5	0.2965	0.5	0.6361	0.078*
C6	0.1763 (6)	0.5	0.5816 (15)	0.047 (2)
C7	0.1497 (8)	0.5	0.3949 (19)	0.069 (4)
H7A	0.1702	0.386	0.3574	0.083*
H7B	0.0919	0.5	0.3473	0.083*

Atomic displacement parameters (Ų)

	U11	U22	U33	U12	U13	U23
Au1	0.0319 (3)	0.0531 (4)	0.0374 (3)	0	0.00961 (19)	0
Au2	0.0327 (3)	0.0502 (4)	0.0538 (3)	0	0.0053 (2)	0
Cl1	0.0327 (12)	0.071 (2)	0.077 (2)	0	−0.0006 (12)	0
Cl2	0.0641 (19)	0.090 (3)	0.0611 (18)	0	0.0195 (15)	0
N1	0.024 (3)	0.050 (5)	0.050 (5)	0	0.002 (3)	0
C1	0.060 (7)	0.097 (12)	0.045 (6)	0	0.017 (5)	0
C2	0.038 (5)	0.065 (8)	0.042 (5)	0	−0.006 (4)	0
C3	0.047 (6)	0.098 (12)	0.047 (6)	0	−0.008 (5)	0
C4	0.036 (6)	0.098 (13)	0.086 (10)	0	0.002 (6)	0
C5	0.045 (6)	0.075 (10)	0.078 (9)	0	0.026 (6)	0
C6	0.040 (5)	0.050 (6)	0.053 (6)	0	0.020 (4)	0
C7	0.057 (7)	0.088 (11)	0.074 (9)	0	0.037 (7)	0

Geometric parameters (Å, °)

Au1—N1	2.030 (8)	C2—C3	1.392 (15)
Au1—N1i	2.030 (8)	C3—C4	1.35 (2)
Au2—Cl1i	2.280 (3)	C3—H3	0.93
Au2—Cl1	2.280 (3)	C4—C5	1.38 (2)
Au2—Cl2	2.286 (4)	C4—H4	0.93
Au2—Cl2i	2.286 (4)	C5—C6	1.381 (17)
N1—C2	1.360 (15)	C5—H5	0.93
N1—C6	1.370 (14)	C6—C7	1.463 (18)
C1—C2	1.479 (18)	C7—H7A	0.96
C1—H1A	0.96	C7—H7B	0.96
C1—H1B	0.96
N1—Au1—N1i	180.0 (3)	C4—C3—C2	118.8 (12)
Cl1i—Au2—Cl1	180.00 (8)	C4—C3—H3	120.6
Cl1i—Au2—Cl2	90.05 (14)	C2—C3—H3	120.6
Cl1—Au2—Cl2	89.95 (14)	C3—C4—C5	121.4 (12)
Cl1i—Au2—Cl2i	89.95 (14)	C3—C4—H4	119.3
Cl1—Au2—Cl2i	90.05 (14)	C5—C4—H4	119.3
Cl2—Au2—Cl2i	180.00 (17)	C4—C5—C6	119.0 (12)
C2—N1—C6	119.6 (9)	C4—C5—H5	120.5
C2—N1—Au1	120.7 (8)	C6—C5—H5	120.5
C6—N1—Au1	119.7 (7)	N1—C6—C5	120.3 (11)
C2—C1—H1A	109.5	N1—C6—C7	117.4 (10)
C2—C1—H1B	109.5	C5—C6—C7	122.3 (11)
H1A—C1—H1B	109.5	C6—C7—H7A	109.5
N1—C2—C3	120.9 (12)	C6—C7—H7B	109.5
N1—C2—C1	118.2 (10)	H7A—C7—H7B	109.5
C3—C2—C1	120.9 (11)
C6—N1—C2—C3	0.000 (4)	C3—C4—C5—C6	0.000 (5)
Au1—N1—C2—C3	180.000 (4)	C2—N1—C6—C5	0.000 (4)
C6—N1—C2—C1	180.000 (4)	Au1—N1—C6—C5	180.000 (3)
Au1—N1—C2—C1	0.000 (3)	C2—N1—C6—C7	180.000 (3)
N1—C2—C3—C4	0.000 (6)	Au1—N1—C6—C7	0.000 (3)
C1—C2—C3—C4	180.000 (5)	C4—C5—C6—N1	0.000 (4)
C2—C3—C4—C5	0.000 (6)	C4—C5—C6—C7	180.000 (4)

Symmetry codes: (i) −x, y, −z+1.

Hydrogen-bond geometry (Å, °)

D—H···A	D—H	H···A	D···A	D—H···A
C3—H3···Cl1ii	0.93	2.77	3.572 (14)	145

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