Bis(8-methyl­quinolinium) tetra­chloridoferrate(III) chloride

The asymmetric unit of the title compound, (C₁₀H₁₀N)₂[FeCl₄]Cl, contains two protonated 8-methyl­quinolinium cations, one chloride anion and one tetra­chloridoferrate(III) anion. The mean Fe—Cl distance is 2.1880 (7) Å. The two 8-methyl­quinolinium cations and chloride anion are connected via N—H...Cl hydrogen bonds. Furthermore, there are stacking inter­actions between cations. N—H...Cl hydrogen bonds link two 8-methyl­quinolinium cations. The bromido analogue is isostructural with the title compound.

Key indicators

• Single-crystal X-ray study
• T = 291 K
• Mean [sigma](C-C) = 0.003 Å
• R factor = 0.029
• wR factor = 0.086
• Data-to-parameter ratio = 16.1

checkCIF/PLATON results

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Alert level B
PLAT230_ALERT_2_B Hirshfeld Test Diff for    C6     -   C7      ..       7.48 su

Alert level C
PLAT242_ALERT_2_C Check Low       Ueq as Compared to Neighbors for        Fe1

Alert level G
PLAT794_ALERT_5_G Check Predicted Bond Valency for Fe1         (3)       3.07

   0 ALERT level A = In general: serious problem
   1 ALERT level B = Potentially serious problem
   1 ALERT level C = Check and explain
   1 ALERT level G = General alerts; check

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

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S1. Comment

The composition of quinolinium and methylquinolinium tetrahalogenoferrates(III) has been found to be distinctly dependent on the location of the methyl substituent in the quinoline ring and the kind of halide ligands in the coordination sphere of Fe(III) (Warnke et al., 2003). When a quinolinum cation is a counter-ion, both the [FeBr₄]^- and [FeCl₄]^- anions form binary (1:1) salts (Wyrzykowski, Sikorski, Konitz et al., 2006). With a 2-methyl substituted quinolinium cation (MeQH), resulting salts have a composition of (2MeQH)₂[FeX₄]X (where X = Br or Cl) (Warnke et al., 2006; Wyrzykowski, Sikorski, Lis et al., 2006). Introduction of the 2-methylquinolie substituted at position 4 by —NH₂ leads again to formation of 1:1 salt (Wyrzykowski, Warnke et al., 2006). The 8-methylquinolie forms (8MeQH)₂[Fe_Br4]Br salt (Kruszynski et al., 2007). Generally in compounds containing aromatic amines acting as balancing cations, replacing the FeBr₄ anions by FeCl₄ anions leads to isostructural compounds: (2MeQH)₂[FeX₄]X (Warnke et al., 2006; Wyrzykowski, Sikorski, Lis et al., 2006), (4ClpyH)₃(FeX₄)₂X (where 4ClpyH means 4-chloropyridinium) (Lowe et al., 1990; Zordan et al., 2005), but cases of non-isostructurality are also known: (pyH)₃(FeX₄)₂X (where pyH means pyridinium) (Shaviv et al., 1992; Lowe et al., 1994). For some compounds, salts with different composition are found for FeCl₄ anions: (pyH)₅(FeX₄)₂X₃ (James et al., 1982). Thus determining the composition of FeCl₄ complex containing quinoline methylated at position 8 was undertaken.

All 8-methylquinolinium cations intramolecular distances and angles in (I) (Fig. 1) can be considered normal. All atoms lie in general positions. The asymmetric unit contains two protonated 8-methylquinolinium cations, one chloride anion and one tetrachloroferrate anion. The mean Fe—Cl distance is 2.1880 (7) Å. Four Cl—Fe—Cl angles are smaller than tetrahedral and and two are greater than tetrahedral one. The 8-methylquinolinium cations can be considered planar and are inclined at 4.71 (7)°. From weighted last squares planes calculated through all non-hydrogen atoms of cations the most deviate atom C10 (about 0.018 (2) Å) in one molecule and C14 (about 0.018 (2) Å) in second molecule. The two 8-methylquinolinium cations and chloride anion are connected via N—H···Cl···H—N hydrogen bonds (Table 2, Fig. 2). The cations are associated via π···π stacking interactions (Table 2) to dimers, and dimers are separated by anions from each other. Thus, in the considered structure, tetrachloroferrate anions play the role of a stacking breaker. The N—H···Cl···H—N hydrogen bonds together with π···π stacking interactions expands molecules to the seminifinite chain along crystallographic b axis (Fig. 2).

Related literature

For the bromo analogue, see: Kruszynski et al. (2007). For details of other tetrahalogenoferrates with quinoline and its derivatives see: Bottomley et al. (1984); Warnke et al. (2006); Wyrzykowski, Sikorski, Konitz et al. (2006); Wyrzykowski, Sikorski, Lis et al. (2006); Wyrzykowski, Warnke et al. (2006); and for similar tetrahalogenoferrates with aromatic amines acting as balancing cations see: Abboud et al. (2005); Barbaro et al. (1992); Chan & Baird (2004); Couce et al. (1995); Daran et al. (1979); James et al. (2001, 1982), Khan et al. (1987); Lowe et al. (1990, 1994); Hackert & Jacobson (1971); Podesta & Orpen (2005); Shaviv et al. (1992); Veidis et al. (1979, 1981); Zora et al. (1990); Zordan et al. (2005). For general synthesis procedures, see: Warnke et al. (2003).

S2. Experimental

The synthesis of the title compound was carried out using a procedure similar to that previously reported for the preparation of bis(8-methylquinolinium) tetrabromidoferrate(III) bromide (Kruszynski et al., 2007). To a solution of FeCl₃ (ca 0.05 mol) in ethanol (96%) (25 ml), a stoichiometric quantity of a 12 mol/dm³ HCl solution and 8-methylquinoline (ca 0.05 mol) were added in turn. After 7 days the title compound precipitated. It was recrystallized from ethanol at ambient temperature. After 2 days yellow crystals appeared. The compound was dried over P₄O₁₀ in a vacuum desiccator. Elemental analysis (calculated/found %): C 46.04/46.36, H 3.84/3.82, N 5.37/5.17, Cl 34.05/33.85, Fe 10.71/10.52.

S3. Refinement

The carbon-bonded hydrogen atoms were placed in calculated positions and were refined as riding on adjacent carbon atom with U_iso(H) = 1.2U_eq(C-non-methyl) and U_iso(H) = 1.5U_eq(C-methyl). The methyl groups were allowed to rotate about their local threefold axis (AFIX 137). The nitrogen-bonded hydrogen atoms were found from difference Fourier synthesis after eight cycles of anisotropic refinement and were refined as riding on adjacent nitrogen atom with U_iso(H) = 1.2U_eq(N).

Computing details

Data collection: CrysAlis CCD (UNIL IC & Kuma, 2000); cell refinement: CrysAlis RED (UNIL IC & Kuma, 2000); data reduction: CrysAlis RED; program(s) used to solve structure: SHELXS97 (Sheldrick, 1990a); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: XP in SHELXTL/PC (Sheldrick, 1990b) and ORTEP-3 (Windows Version 1.062; Farrugia 1997); software used to prepare material for publication: SHELXL97 and PLATON (Spek, 1990).

Figures

	Fig. 1. Molecular structure of the title compound (I). Displacement ellipsoids are drawn at the 50% probability level.
	Fig. 2. A part of the molecular packing of the title compound showing short intermolecular interactions (hydrogen bonds are indicated by dashed lines).

Bis(8-methylquinolinium) tetrachloridoferrate(III) chloride

Crystal data

(C10H10N)2[FeCl4]Cl	Z = 2
Mr = 521.48	F(000) = 530
Triclinic, P1	Dx = 1.497 Mg m^−3 Dm = 1.50 Mg m^−3 Dm measured by Berman density torsion balance
Hall symbol: -P 1	Mo Kα radiation, λ = 0.71073 Å
a = 7.9065 (3) Å	Cell parameters from 6196 reflections
b = 10.1445 (3) Å	θ = 5–20°
c = 14.8518 (6) Å	µ = 1.24 mm^−1
α = 84.097 (3)°	T = 291 K
β = 78.200 (3)°	Needle, yellow
γ = 84.869 (2)°	0.38 × 0.10 × 0.06 mm
V = 1157.00 (7) Å^3

Data collection

Kuma KM-4-CCD diffractometer	4101 independent reflections
Radiation source: fine-focus sealed tube	3257 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.039
Detector resolution: 1048576 pixels mm^-1	θmax = 25.1°, θmin = 2.0°
ω scans	h = −9→8
Absorption correction: numerical (X-RED; Stoe & Cie, 1999)	k = −12→12
Tmin = 0.861, Tmax = 0.919	l = −16→17
11265 measured reflections

Refinement

Refinement on F^2	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: structure-invariant direct methods
R[F^2 > 2σ(F^2)] = 0.029	Hydrogen site location: mixed
wR(F^2) = 0.086	H-atom parameters constrained
S = 1.09	w = 1/[σ^2(Fo^2) + (0.0487P)^2] where P = (Fo^2 + 2Fc^2)/3
4101 reflections	(Δ/σ)max = 0.001
255 parameters	Δρmax = 0.33 e Å^−3
0 restraints	Δρmin = −0.29 e Å^−3

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.

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
Fe1	0.84101 (4)	0.23561 (3)	0.128413 (19)	0.04951 (12)
Cl1	0.82335 (8)	0.02684 (6)	0.10945 (4)	0.06251 (17)
Cl2	1.08019 (8)	0.30260 (6)	0.03856 (4)	0.06542 (18)
Cl4	0.61592 (9)	0.35139 (7)	0.08881 (5)	0.0759 (2)
Cl5	0.85692 (11)	0.25261 (9)	0.27133 (4)	0.0882 (2)
N1	0.3990 (2)	1.01488 (17)	0.24864 (11)	0.0513 (4)
H1N	0.3935	1.0690	0.2983	0.062*
C1	0.3282 (3)	1.0698 (2)	0.17910 (15)	0.0606 (6)
H1	0.2776	1.1561	0.1810	0.073*
C2	0.3285 (3)	1.0010 (3)	0.10422 (16)	0.0685 (7)
H2	0.2783	1.0398	0.0556	0.082*
C3	0.4035 (3)	0.8752 (3)	0.10222 (15)	0.0622 (6)
H3	0.4057	0.8284	0.0513	0.075*
C4	0.4772 (3)	0.8150 (2)	0.17530 (14)	0.0523 (5)
C5	0.4737 (3)	0.8883 (2)	0.25102 (13)	0.0450 (5)
C6	0.5517 (3)	0.6842 (2)	0.17673 (19)	0.0650 (6)
H6	0.5559	0.6342	0.1271	0.078*
C7	0.6166 (3)	0.6318 (3)	0.2500 (2)	0.0772 (8)
H7	0.6645	0.5447	0.2512	0.093*
C8	0.6136 (3)	0.7065 (3)	0.32554 (19)	0.0678 (7)
H8	0.6609	0.6674	0.3751	0.081*
C9	0.5436 (3)	0.8341 (2)	0.32818 (15)	0.0554 (5)
C10	0.5423 (4)	0.9154 (3)	0.40664 (16)	0.0757 (8)
H10A	0.5891	0.8618	0.4541	0.114*
H10B	0.4254	0.9469	0.4311	0.114*
H10C	0.6113	0.9897	0.3851	0.114*
N11	0.1904 (2)	0.51280 (17)	0.30506 (11)	0.0500 (4)
H11N	0.2380	0.4449	0.3429	0.060*
C11	0.1783 (3)	0.4871 (2)	0.22141 (15)	0.0580 (6)
H11	0.2165	0.4037	0.2013	0.070*
C12	0.1095 (3)	0.5828 (2)	0.16336 (16)	0.0628 (6)
H12	0.1022	0.5649	0.1042	0.075*
C13	0.0529 (3)	0.7029 (2)	0.19396 (15)	0.0569 (6)
H13	0.0034	0.7671	0.1559	0.068*
C14	0.0673 (3)	0.7326 (2)	0.28227 (14)	0.0476 (5)
C15	0.1394 (3)	0.6330 (2)	0.33969 (13)	0.0446 (5)
C16	0.0135 (3)	0.8566 (2)	0.31588 (17)	0.0628 (6)
H16	−0.0348	0.9236	0.2793	0.075*
C17	0.0315 (4)	0.8789 (3)	0.40055 (18)	0.0784 (8)
H17	−0.0032	0.9619	0.4222	0.094*
C18	0.1020 (4)	0.7788 (3)	0.45683 (17)	0.0718 (7)
H18	0.1104	0.7966	0.5159	0.086*
C19	0.1590 (3)	0.6560 (2)	0.42852 (14)	0.0551 (6)
C20	0.2383 (4)	0.5506 (3)	0.48932 (16)	0.0733 (7)
H20A	0.2492	0.5869	0.5449	0.110*
H20B	0.3507	0.5201	0.4572	0.110*
H20C	0.1655	0.4774	0.5047	0.110*
Cl99	0.31343 (11)	0.23929 (7)	0.37586 (4)	0.0810 (2)

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Fe1	0.0657 (2)	0.04101 (19)	0.04674 (18)	0.00170 (14)	−0.02298 (14)	−0.00737 (12)
Cl1	0.0779 (4)	0.0394 (3)	0.0755 (4)	−0.0032 (3)	−0.0279 (3)	−0.0049 (2)
Cl2	0.0801 (4)	0.0563 (4)	0.0618 (3)	−0.0113 (3)	−0.0194 (3)	0.0021 (3)
Cl4	0.0841 (4)	0.0607 (4)	0.0900 (4)	0.0244 (3)	−0.0386 (3)	−0.0223 (3)
Cl5	0.1168 (6)	0.1058 (6)	0.0494 (3)	−0.0085 (5)	−0.0284 (3)	−0.0168 (3)
N1	0.0686 (12)	0.0436 (10)	0.0443 (9)	0.0053 (9)	−0.0179 (8)	−0.0098 (7)
C1	0.0774 (16)	0.0508 (14)	0.0555 (13)	0.0066 (12)	−0.0240 (11)	−0.0008 (10)
C2	0.0866 (18)	0.0747 (19)	0.0501 (13)	−0.0060 (14)	−0.0285 (12)	−0.0023 (12)
C3	0.0740 (16)	0.0723 (18)	0.0451 (12)	−0.0168 (13)	−0.0116 (11)	−0.0174 (11)
C4	0.0558 (13)	0.0501 (13)	0.0516 (12)	−0.0104 (10)	−0.0034 (10)	−0.0151 (10)
C5	0.0508 (12)	0.0401 (11)	0.0438 (10)	0.0006 (9)	−0.0080 (9)	−0.0081 (8)
C6	0.0631 (15)	0.0507 (15)	0.0796 (16)	−0.0018 (12)	−0.0019 (12)	−0.0236 (12)
C7	0.0704 (17)	0.0424 (14)	0.113 (2)	0.0083 (12)	−0.0048 (15)	−0.0156 (14)
C8	0.0660 (15)	0.0542 (15)	0.0826 (17)	0.0083 (12)	−0.0233 (13)	0.0032 (13)
C9	0.0637 (14)	0.0481 (13)	0.0549 (12)	0.0059 (11)	−0.0173 (10)	−0.0043 (10)
C10	0.102 (2)	0.0740 (18)	0.0588 (14)	0.0181 (15)	−0.0408 (13)	−0.0118 (12)
N11	0.0620 (11)	0.0394 (10)	0.0502 (10)	−0.0013 (8)	−0.0195 (8)	0.0031 (7)
C11	0.0800 (16)	0.0412 (12)	0.0568 (13)	−0.0017 (11)	−0.0220 (11)	−0.0081 (10)
C12	0.0945 (18)	0.0470 (14)	0.0544 (13)	−0.0078 (12)	−0.0313 (12)	−0.0029 (10)
C13	0.0705 (15)	0.0488 (13)	0.0553 (13)	−0.0043 (11)	−0.0266 (11)	0.0064 (10)
C14	0.0494 (12)	0.0410 (12)	0.0528 (11)	−0.0007 (9)	−0.0139 (9)	0.0004 (9)
C15	0.0478 (11)	0.0398 (11)	0.0448 (11)	−0.0007 (9)	−0.0080 (8)	−0.0012 (8)
C16	0.0712 (16)	0.0481 (14)	0.0681 (15)	0.0134 (11)	−0.0199 (12)	−0.0037 (11)
C17	0.101 (2)	0.0611 (17)	0.0747 (17)	0.0241 (15)	−0.0230 (15)	−0.0260 (13)
C18	0.095 (2)	0.0710 (18)	0.0510 (13)	0.0126 (15)	−0.0188 (12)	−0.0174 (12)
C19	0.0646 (14)	0.0540 (14)	0.0460 (11)	0.0038 (11)	−0.0134 (10)	−0.0026 (10)
C20	0.103 (2)	0.0677 (17)	0.0531 (13)	0.0077 (15)	−0.0325 (13)	−0.0006 (12)
Cl99	0.1340 (6)	0.0521 (4)	0.0576 (3)	0.0333 (4)	−0.0340 (4)	−0.0127 (3)

Geometric parameters (Å, º)

Fe1—Cl5	2.1770 (7)	C10—H10B	0.9600
Fe1—Cl1	2.1853 (7)	C10—H10C	0.9600
Fe1—Cl4	2.1921 (7)	N11—C11	1.319 (3)
Fe1—Cl2	2.1977 (7)	N11—C15	1.368 (3)
N1—C1	1.324 (3)	N11—H11N	0.9444
N1—C5	1.365 (3)	C11—C12	1.381 (3)
N1—H1N	0.9560	C11—H11	0.9300
C1—C2	1.372 (3)	C12—C13	1.351 (3)
C1—H1	0.9300	C12—H12	0.9300
C2—C3	1.358 (4)	C13—C14	1.404 (3)
C2—H2	0.9300	C13—H13	0.9300
C3—C4	1.396 (3)	C14—C16	1.401 (3)
C3—H3	0.9300	C14—C15	1.411 (3)
C4—C6	1.403 (3)	C15—C19	1.404 (3)
C4—C5	1.405 (3)	C16—C17	1.338 (3)
C5—C9	1.413 (3)	C16—H16	0.9300
C6—C7	1.338 (4)	C17—C18	1.399 (4)
C6—H6	0.9300	C17—H17	0.9300
C7—C8	1.412 (4)	C18—C19	1.364 (3)
C7—H7	0.9300	C18—H18	0.9300
C8—C9	1.362 (3)	C19—C20	1.505 (3)
C8—H8	0.9300	C20—H20A	0.9600
C9—C10	1.493 (3)	C20—H20B	0.9600
C10—H10A	0.9600	C20—H20C	0.9600
Cl5—Fe1—Cl1	108.91 (3)	C9—C10—H10C	109.5
Cl5—Fe1—Cl4	112.49 (3)	H10A—C10—H10C	109.5
Cl1—Fe1—Cl4	108.72 (3)	H10B—C10—H10C	109.5
Cl5—Fe1—Cl2	108.64 (3)	C11—N11—C15	123.54 (18)
Cl1—Fe1—Cl2	108.12 (3)	C11—N11—H11N	118.3
Cl4—Fe1—Cl2	109.85 (3)	C15—N11—H11N	118.2
C1—N1—C5	122.81 (19)	N11—C11—C12	120.6 (2)
C1—N1—H1N	115.9	N11—C11—H11	119.7
C5—N1—H1N	121.3	C12—C11—H11	119.7
N1—C1—C2	120.8 (2)	C13—C12—C11	119.0 (2)
N1—C1—H1	119.6	C13—C12—H12	120.5
C2—C1—H1	119.6	C11—C12—H12	120.5
C3—C2—C1	118.9 (2)	C12—C13—C14	121.1 (2)
C3—C2—H2	120.5	C12—C13—H13	119.4
C1—C2—H2	120.5	C14—C13—H13	119.4
C2—C3—C4	121.1 (2)	C16—C14—C13	122.9 (2)
C2—C3—H3	119.4	C16—C14—C15	118.5 (2)
C4—C3—H3	119.4	C13—C14—C15	118.6 (2)
C3—C4—C6	122.7 (2)	N11—C15—C19	121.17 (18)
C3—C4—C5	118.3 (2)	N11—C15—C14	117.16 (18)
C6—C4—C5	118.9 (2)	C19—C15—C14	121.67 (19)
N1—C5—C4	117.97 (19)	C17—C16—C14	120.0 (2)
N1—C5—C9	120.19 (19)	C17—C16—H16	120.0
C4—C5—C9	121.8 (2)	C14—C16—H16	120.0
C7—C6—C4	119.5 (2)	C16—C17—C18	120.7 (2)
C7—C6—H6	120.2	C16—C17—H17	119.7
C4—C6—H6	120.2	C18—C17—H17	119.7
C6—C7—C8	121.2 (2)	C19—C18—C17	122.6 (2)
C6—C7—H7	119.4	C19—C18—H18	118.7
C8—C7—H7	119.4	C17—C18—H18	118.7
C9—C8—C7	122.1 (2)	C18—C19—C15	116.5 (2)
C9—C8—H8	118.9	C18—C19—C20	121.8 (2)
C7—C8—H8	118.9	C15—C19—C20	121.7 (2)
C8—C9—C5	116.4 (2)	C19—C20—H20A	109.5
C8—C9—C10	122.8 (2)	C19—C20—H20B	109.5
C5—C9—C10	120.7 (2)	H20A—C20—H20B	109.5
C9—C10—H10A	109.5	C19—C20—H20C	109.5
C9—C10—H10B	109.5	H20A—C20—H20C	109.5
H10A—C10—H10B	109.5	H20B—C20—H20C	109.5

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
N1—H1N···Cl99^i	0.96	2.15	3.0490 (18)	156
N11—H11N···Cl99	0.94	2.15	3.0143 (18)	151

Symmetry code: (i) x, y+1, z.