Bis(triethyl­ammonium) tetra­chlorido­manganate(II)

The title compound, (Et₃NH)₂[MnCl₄], was obtained unexpectedly in an attempt to prepare a carboxyl­ate-bridged coordination network. It is the first reported structure of a tertiary ammonium salt of the tetra­hedral [MnCl₄]²⁻ anion (Table 1). Each of the two crystallographically independent cations forms an N—H...Cl hydrogen bond to the anion (Table 2), generating discrete ion triples. The Mn—Cl bonds involving the hydrogen-bonded Cl atoms are longer than the others.

Key indicators

• Single-crystal X-ray study
• T = 160 K
• Mean [sigma](C-C) = 0.005 Å
• R factor = 0.038
• wR factor = 0.090
• Data-to-parameter ratio = 19.4

checkCIF/PLATON results

No syntax errors found



Alert level A
PLAT222_ALERT_3_A Large Non-Solvent    H     Ueq(max)/Ueq(min) ...       5.29 Ratio

Author Response: Together with some residual electron density peaks, this indicates probable minor disorder in one of the cations, but the disorder could not be resolved satisfactorily as discrete atom sites. The geometry of the current ordered structural model is entirely satisfactory, including hydrogen bonding involving freely refined NH groups.

Alert level B
PLAT027_ALERT_3_B _diffrn_reflns_theta_full (too) Low ............      24.99 Deg.

Alert level C
PLAT094_ALERT_2_C Ratio of Maximum / Minimum Residual Density ....       2.34
PLAT125_ALERT_4_C No _symmetry_space_group_name_Hall Given .......          ?
PLAT222_ALERT_3_C Large Non-Solvent    H     Ueq(max)/Ueq(min) ...       3.03 Ratio

Author Response: Together with some residual electron density peaks, this indicates probable minor disorder in one of the cations, but the disorder could not be resolved satisfactorily as discrete atom sites. The geometry of the current ordered structural model is entirely satisfactory, including hydrogen bonding involving freely refined NH groups.

PLAT242_ALERT_2_C Check Low       Ueq as Compared to Neighbors for         N2
PLAT242_ALERT_2_C Check Low       Ueq as Compared to Neighbors for         Mn
PLAT245_ALERT_2_C U(iso) H2      Smaller than U(eq) N2      by ...       0.01 AngSq
PLAT250_ALERT_2_C Large U3/U1 Ratio for Average U(i,j) Tensor ....       2.08

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

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

---

S1. Comment

The title compound is the first reported for a tertiary ammonium salt of the [MnCl₄]^2- anion. The Cambridge Structural Database (Version 5.27 plus three updates, August 2006; Allen, 2002) contains several entries for primary alkylammonium salts and for quaternary alkylammonium salts, but none for secondary or tertiary ammonium salts. The full list of CSD REFCODES is as follows: for primary ammonium salts, BUAMCM, BUAMCM01, EAMNCL02, EAMNCL03, EAMNCL04, MATCMN08, MATCMN13, NAMNCL, OAMNCL, ZZZBMM, ZZZBMM01, ZZZBMP, ZZZBMP01, ZZZBMS, ZZZBMS01; for quaternary ammonium salts (the tetramethylammonium salt in each case), KAUWAF and the series KAUWAF01–06.

Related literature

The Cambridge Structural Database (Version 5.27 plus three updates, August 2006; Allen, 2002) contains several entries for primary and quaternary ammonium salts (a full list of REFCODES is given in the deposited Comment section), but there are no previously reported structures for secondary or tertiary ammonium salts.

S2. Experimental

The compound was obtained unexpectedly in an unsuccessful attempt to prepare a polymeric carboxylate-bridged manganese complex. Crystals were obtained by vapour diffusion of triethylamine into a solution of manganese(II) chloride and pyromellitic acid in n-propanol.

S3. Refinement

N-bound H atoms were located in a difference map and refined isotropically; bond lengths are given in Table 2. Other H atoms were positioned geometrically and refined with a riding model (including free rotation about C—C bonds), with U_iso(H) = 1.2 (1.5 for methyl groups) times U_eq(C).

Residual electron density peaks associated with one of the cations, the largest of which lies 1.04 Å from H12C, indicate possible minor disorder of this cation, but it could not be satisfactorily resolved.

Computing details

Data collection: SMART (Bruker, 2001); cell refinement: SAINT (Bruker, 2001); data reduction: SAINT; program(s) used to solve structure: SHELXTL (Sheldrick, 2001); program(s) used to refine structure: SHELXTL; molecular graphics: SHELXTL; software used to prepare material for publication: SHELXTL and local programs.

Figures

	Fig. 1. The asymmetric unit with atom labels and 50% probability ellipsoids for non-H atoms. Hydrogen bonds are shown as dashed lines.
	Fig. 2. The packing, viewed along the c axis. Hydrogen bonds are shown as dashed lines, and H atoms not involved in hydrogen bonding have been omitted.

Bis(triethylammonium) tetrachloridomanganate(II)

Crystal data

(C6H16N)[MnCl4]	Dx = 1.301 Mg m^−3
Mr = 401.14	Mo Kα radiation, λ = 0.71073 Å
Orthorhombic, Pbca	Cell parameters from 24268 reflections
a = 12.0533 (5) Å	θ = 2.2–28.4°
b = 13.0595 (6) Å	µ = 1.16 mm^−1
c = 26.0147 (11) Å	T = 160 K
V = 4095.0 (3) Å^3	Tablet, colourless
Z = 8	0.40 × 0.24 × 0.10 mm
F(000) = 1688

Data collection

Bruker SMART 1K CCD diffractometer	3602 independent reflections
Radiation source: sealed tube	3293 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.028
Detector resolution: 8.192 pixels mm^-1	θmax = 25.0°, θmin = 1.6°
Thin–slice ω scans	h = −14→14
Absorption correction: multi-scan (SADABS; Sheldrick, 2004)	k = −15→15
Tmin = 0.650, Tmax = 0.900	l = −30→30
27106 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)] = 0.038	Hydrogen site location: mixed
wR(F^2) = 0.090	H atoms treated by a mixture of independent and constrained refinement
S = 1.10	w = 1/[σ^2(Fo^2) + (0.0267P)^2 + 7.4604P] where P = (Fo^2 + 2Fc^2)/3
3602 reflections	(Δ/σ)max = 0.001
186 parameters	Δρmax = 1.21 e Å^−3
0 restraints	Δρmin = −0.52 e Å^−3

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

	x	y	z	Uiso*/Ueq
Mn	0.94241 (3)	0.20976 (3)	0.373324 (15)	0.02832 (12)
Cl1	0.77218 (6)	0.16735 (6)	0.41181 (3)	0.04164 (19)
Cl2	0.90717 (6)	0.25111 (7)	0.28522 (3)	0.0465 (2)
Cl3	1.01603 (8)	0.35169 (6)	0.41945 (4)	0.0569 (3)
Cl4	1.07413 (6)	0.07780 (6)	0.37680 (3)	0.03715 (18)
N1	0.88971 (18)	0.30677 (17)	0.52513 (9)	0.0274 (5)
H1	0.916 (3)	0.310 (2)	0.4937 (12)	0.033 (8)*
C1	0.9667 (3)	0.3711 (2)	0.55729 (13)	0.0418 (7)
H1A	1.0422	0.3416	0.5555	0.050*
H1B	0.9700	0.4410	0.5426	0.050*
C2	0.9322 (4)	0.3784 (3)	0.61257 (14)	0.0665 (12)
H2A	0.8558	0.4037	0.6146	0.100*
H2B	0.9817	0.4256	0.6307	0.100*
H2C	0.9365	0.3105	0.6285	0.100*
C3	0.7737 (2)	0.3483 (2)	0.52237 (12)	0.0361 (7)
H3A	0.7401	0.3458	0.5571	0.043*
H3B	0.7289	0.3040	0.4995	0.043*
C4	0.7694 (3)	0.4567 (2)	0.50269 (15)	0.0512 (9)
H4A	0.8050	0.5025	0.5276	0.077*
H4B	0.6919	0.4773	0.4979	0.077*
H4C	0.8086	0.4609	0.4697	0.077*
C5	0.8878 (2)	0.1958 (2)	0.54057 (11)	0.0326 (6)
H5A	0.8289	0.1602	0.5210	0.039*
H5B	0.8690	0.1909	0.5775	0.039*
C6	0.9967 (3)	0.1424 (2)	0.53127 (12)	0.0383 (7)
H6A	1.0144	0.1446	0.4945	0.057*
H6B	0.9911	0.0709	0.5425	0.057*
H6C	1.0554	0.1769	0.5507	0.057*
N2	0.7331 (2)	0.4321 (2)	0.26021 (9)	0.0347 (6)
H2	0.777 (2)	0.392 (2)	0.2724 (11)	0.024 (8)*
C7	0.6735 (3)	0.3934 (3)	0.21350 (12)	0.0540 (9)
H7A	0.6179	0.3420	0.2244	0.065*
H7B	0.6331	0.4510	0.1974	0.065*
C8	0.7483 (3)	0.3460 (3)	0.17435 (11)	0.0472 (8)
H8A	0.7984	0.3983	0.1605	0.071*
H8B	0.7037	0.3172	0.1464	0.071*
H8C	0.7919	0.2914	0.1905	0.071*
C9	0.6545 (3)	0.4546 (2)	0.30393 (12)	0.0442 (8)
H9A	0.6955	0.4907	0.3315	0.053*
H9B	0.5955	0.5011	0.2915	0.053*
C10	0.6017 (3)	0.3606 (2)	0.32609 (12)	0.0432 (8)
H10A	0.5560	0.3273	0.2998	0.065*
H10B	0.5550	0.3798	0.3554	0.065*
H10C	0.6596	0.3131	0.3376	0.065*
C11	0.7970 (3)	0.5261 (3)	0.24499 (16)	0.0634 (11)
H11A	0.8393	0.5111	0.2132	0.076*
H11B	0.7438	0.5816	0.2370	0.076*
C12	0.8728 (4)	0.5618 (4)	0.28370 (18)	0.0848 (16)
H12A	0.8309	0.5878	0.3132	0.127*
H12B	0.9189	0.6168	0.2695	0.127*
H12C	0.9204	0.5051	0.2948	0.127*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Mn	0.0306 (2)	0.0269 (2)	0.0275 (2)	0.00058 (17)	0.00401 (17)	0.00198 (17)
Cl1	0.0328 (4)	0.0557 (5)	0.0364 (4)	−0.0059 (3)	0.0066 (3)	0.0057 (3)
Cl2	0.0430 (4)	0.0630 (5)	0.0336 (4)	0.0144 (4)	0.0062 (3)	0.0181 (4)
Cl3	0.0719 (6)	0.0351 (4)	0.0638 (5)	−0.0251 (4)	0.0385 (5)	−0.0207 (4)
Cl4	0.0374 (4)	0.0358 (4)	0.0383 (4)	0.0075 (3)	−0.0082 (3)	−0.0061 (3)
N1	0.0272 (12)	0.0231 (11)	0.0318 (12)	−0.0021 (9)	0.0061 (10)	−0.0044 (9)
C1	0.0349 (16)	0.0295 (15)	0.061 (2)	−0.0059 (13)	−0.0072 (15)	−0.0073 (14)
C2	0.102 (3)	0.049 (2)	0.049 (2)	−0.008 (2)	−0.021 (2)	−0.0112 (17)
C3	0.0266 (15)	0.0322 (16)	0.0494 (17)	0.0007 (12)	0.0038 (13)	−0.0078 (13)
C4	0.0386 (18)	0.0327 (17)	0.082 (3)	0.0079 (14)	−0.0009 (17)	0.0014 (17)
C5	0.0387 (16)	0.0242 (14)	0.0350 (15)	−0.0046 (12)	0.0028 (12)	−0.0008 (12)
C6	0.0468 (18)	0.0312 (15)	0.0368 (16)	0.0064 (14)	−0.0008 (14)	0.0009 (13)
N2	0.0350 (14)	0.0338 (14)	0.0352 (13)	−0.0004 (12)	0.0113 (11)	−0.0001 (11)
C7	0.0367 (17)	0.093 (3)	0.0328 (16)	0.0095 (18)	−0.0009 (14)	0.0078 (17)
C8	0.0406 (17)	0.071 (2)	0.0305 (15)	−0.0052 (17)	−0.0033 (14)	−0.0066 (16)
C9	0.0506 (19)	0.0378 (17)	0.0443 (18)	0.0024 (15)	0.0224 (15)	−0.0041 (14)
C10	0.0459 (18)	0.0438 (18)	0.0401 (17)	0.0030 (15)	0.0152 (14)	0.0055 (14)
C11	0.063 (2)	0.058 (2)	0.069 (3)	−0.014 (2)	0.022 (2)	−0.001 (2)
C12	0.065 (3)	0.102 (4)	0.088 (3)	−0.042 (3)	0.030 (2)	−0.047 (3)

Geometric parameters (Å, º)

Mn—Cl1	2.3492 (8)	C6—H6B	0.980
Mn—Cl2	2.3927 (8)	C6—H6C	0.980
Mn—Cl3	2.3797 (9)	N2—H2	0.82 (3)
Mn—Cl4	2.3449 (8)	N2—C7	1.500 (4)
N1—H1	0.88 (3)	N2—C9	1.510 (4)
N1—C1	1.506 (4)	N2—C11	1.502 (4)
N1—C3	1.501 (3)	C7—H7A	0.990
N1—C5	1.504 (3)	C7—H7B	0.990
C1—H1A	0.990	C7—C8	1.494 (5)
C1—H1B	0.990	C8—H8A	0.980
C1—C2	1.500 (5)	C8—H8B	0.980
C2—H2A	0.980	C8—H8C	0.980
C2—H2B	0.980	C9—H9A	0.990
C2—H2C	0.980	C9—H9B	0.990
C3—H3A	0.990	C9—C10	1.499 (4)
C3—H3B	0.990	C10—H10A	0.980
C3—C4	1.507 (4)	C10—H10B	0.980
C4—H4A	0.980	C10—H10C	0.980
C4—H4B	0.980	C11—H11A	0.990
C4—H4C	0.980	C11—H11B	0.990
C5—H5A	0.990	C11—C12	1.438 (6)
C5—H5B	0.990	C12—H12A	0.980
C5—C6	1.506 (4)	C12—H12B	0.980
C6—H6A	0.980	C12—H12C	0.980
Cl1—Mn—Cl2	107.84 (3)	H6A—C6—H6B	109.5
Cl1—Mn—Cl3	107.12 (3)	H6A—C6—H6C	109.5
Cl1—Mn—Cl4	113.68 (3)	H6B—C6—H6C	109.5
Cl2—Mn—Cl3	111.93 (4)	H2—N2—C7	114 (2)
Cl2—Mn—Cl4	108.84 (3)	H2—N2—C9	104 (2)
Cl3—Mn—Cl4	107.49 (4)	H2—N2—C11	107 (2)
H1—N1—C1	105 (2)	C7—N2—C9	112.0 (2)
H1—N1—C3	106 (2)	C7—N2—C11	107.9 (3)
H1—N1—C5	108 (2)	C9—N2—C11	111.2 (3)
C1—N1—C3	113.5 (2)	N2—C7—H7A	108.8
C1—N1—C5	113.5 (2)	N2—C7—H7B	108.8
C3—N1—C5	110.3 (2)	N2—C7—C8	113.8 (3)
N1—C1—H1A	108.9	H7A—C7—H7B	107.7
N1—C1—H1B	108.9	H7A—C7—C8	108.8
N1—C1—C2	113.4 (3)	H7B—C7—C8	108.8
H1A—C1—H1B	107.7	C7—C8—H8A	109.5
H1A—C1—C2	108.9	C7—C8—H8B	109.5
H1B—C1—C2	108.9	C7—C8—H8C	109.5
C1—C2—H2A	109.5	H8A—C8—H8B	109.5
C1—C2—H2B	109.5	H8A—C8—H8C	109.5
C1—C2—H2C	109.5	H8B—C8—H8C	109.5
H2A—C2—H2B	109.5	N2—C9—H9A	108.9
H2A—C2—H2C	109.5	N2—C9—H9B	108.9
H2B—C2—H2C	109.5	N2—C9—C10	113.4 (3)
N1—C3—H3A	109.0	H9A—C9—H9B	107.7
N1—C3—H3B	109.0	H9A—C9—C10	108.9
N1—C3—C4	112.8 (2)	H9B—C9—C10	108.9
H3A—C3—H3B	107.8	C9—C10—H10A	109.5
H3A—C3—C4	109.0	C9—C10—H10B	109.5
H3B—C3—C4	109.0	C9—C10—H10C	109.5
C3—C4—H4A	109.5	H10A—C10—H10B	109.5
C3—C4—H4B	109.5	H10A—C10—H10C	109.5
C3—C4—H4C	109.5	H10B—C10—H10C	109.5
H4A—C4—H4B	109.5	N2—C11—H11A	108.8
H4A—C4—H4C	109.5	N2—C11—H11B	108.8
H4B—C4—H4C	109.5	N2—C11—C12	114.0 (4)
N1—C5—H5A	109.0	H11A—C11—H11B	107.7
N1—C5—H5B	109.0	H11A—C11—C12	108.8
N1—C5—C6	113.0 (2)	H11B—C11—C12	108.8
H5A—C5—H5B	107.8	C11—C12—H12A	109.5
H5A—C5—C6	109.0	C11—C12—H12B	109.5
H5B—C5—C6	109.0	C11—C12—H12C	109.5
C5—C6—H6A	109.5	H12A—C12—H12B	109.5
C5—C6—H6B	109.5	H12A—C12—H12C	109.5
C5—C6—H6C	109.5	H12B—C12—H12C	109.5
C3—N1—C1—C2	62.1 (4)	C9—N2—C7—C8	−165.6 (3)
C5—N1—C1—C2	−64.8 (3)	C11—N2—C7—C8	71.6 (4)
C1—N1—C3—C4	56.3 (4)	C7—N2—C9—C10	68.1 (4)
C5—N1—C3—C4	−175.1 (3)	C11—N2—C9—C10	−171.0 (3)
C1—N1—C5—C6	−65.9 (3)	C7—N2—C11—C12	−170.1 (3)
C3—N1—C5—C6	165.5 (2)	C9—N2—C11—C12	66.6 (4)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
N1—H1···Cl3	0.88 (3)	2.34 (3)	3.197 (2)	166 (3)
N2—H2···Cl2	0.82 (3)	2.43 (3)	3.227 (3)	164 (3)