Bis[benz­yl(meth­yl)ammonium] tetra­thio­molybdate(VI)

The title compound, (C₈H₁₂N)₂[MoS₄], was synthesized by the aqueous reaction of ammonium tetra­thio­molybdate with benzyl­(methyl)­amine in a 1:2 molar ratio. The structure consists of a slightly distorted tetra­hedral [MoS₄]²⁻ dianion and two crystallographically independent benzyl­(methyl)­ammonium cations, with all atoms located in general positions. The cations and anions are linked by weak N—H...S and C—H...S inter­actions, the strength and number of which can explain the observed Mo—S bond distances.

Key indicators

• Single-crystal X-ray study
• T = 298 K
• Mean [sigma](C-C) = 0.009 Å
• R factor = 0.050
• wR factor = 0.100
• Data-to-parameter ratio = 17.3

checkCIF/PLATON results

No syntax errors found



Alert level C
PLAT029_ALERT_3_C _diffrn_measured_fraction_theta_full Low .......       0.98
PLAT242_ALERT_2_C Check Low       Ueq as Compared to Neighbors for        Mo1
PLAT331_ALERT_2_C Small Average Phenyl C-C Dist.   C1     -C6            1.37 Ang.
PLAT342_ALERT_3_C Low Bond Precision on C-C Bonds (x 1000) Ang ...          9
PLAT480_ALERT_4_C Long H...A H-Bond Reported H2B    ..  S2      ..       2.93 Ang.
PLAT480_ALERT_4_C Long H...A H-Bond Reported H7B    ..  S3      ..       2.92 Ang.
PLAT480_ALERT_4_C Long H...A H-Bond Reported H15A   ..  S1      ..       2.91 Ang.

Alert level G
PLAT794_ALERT_5_G Check Predicted Bond Valency for Mo1         (6)       6.11

   0 ALERT level A = In general: serious problem
   0 ALERT level B = Potentially serious problem
   7 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
   2 ALERT type 3 Indicator that the structure quality may be low
   3 ALERT type 4 Improvement, methodology, query or suggestion
   1 ALERT type 5 Informative message, check

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S1. Comment

As part of an ongoing research programme, we are investigating the synthesis and structural characterization of organic ammonium tetrathiometalates of the group VI metals Mo and W (Srinivasan, Naik et al., 2007). In earlier work we have structurally characterized several [MoS₄]^2- compounds derived from organic diamines (Srinivasan et al., 2001; Srinivasan, Dhuri et al., 2005; Srinivasan, Näther & Bensch, 2005), chiral amines (Srinivasan, Naik et al., 2007) triamines (Srinivasan, Dhuri et al., 2007), cyclic amines (Srinivasan, Näther & Bensch, 2006), tetraamine (Srinivasan et al., 2004) and primary amine (Srinivasan, Näther et al., 2006). All the organic ammonium tetrathiomolybdates exhibit several weak hydrogen bonding interactions between the organic cations and [MoS₄]^2- anions. We have also shown that in some organic [MoS₄]^2- compounds the organic amines are partially protonated (Srinivasan, Dhuri et al., 2007). The secondary amine N-methyl-1-phenylmethanamine used for the synthesis of the title compound (I) is an isomer of the chiral primary amine 1-phenylethanamine used in our earlier report (Srinivasan, Naik et al., 2007).

The structure of (I) consists of discrete tetrahedral [MoS₄]^2- ions and two crystallographically independent benzyl(methyl)ammonium cations (Fig. 1) with all atoms located in general positions. The [MoS₄] tetrahedron is slightly distorted with S—Mo—S angles between 109.01 (6) and 110.28 (7)° (Table 1). The Mo—S bond lengths range from 2.1582 (13) to 2.1908 (14) Å with an average value of 2.1744 Å which is comparable to the bond lengths observed in the related chiral [MoS₄]^2- compound synthesized from the isomeric chiral primary amine (Srinivasan, Naik et al., 2007). The Mo1—S1 and Mo1—S2 bond distances are indistinguishable within experimental error as also the Mo1—S3 and Mo1—S4 bonds. The weak H-bonding interactions between the cations and anions can explain the observed short and long Mo—S bond distances. A scrutiny of the structure reveals that the organic cations and tetrathiomolybdate anions are linked with the aid of several N—H···S and C—H···S hydrogen bonding interactions. Thus each [MoS₄]^2- is hydrogen bonded to five different organic cations with the aid of six N—H···S bonds and two weak C—H···S interactions (Fig. 2). An examination of the surroundings of the cations reveals that one organic cation (N1) is H-bonded to two different [MoS₄]^2- ions while the second organic cation (N2) is surrounded by three different [MoS₄]^2- ions (Table 2). One H atom on each N atom functions as a singly shared donor with the other functioning as a bifurcated donor. A benzilic H atom from each unique cation is involved in C—H···S interaction. S4 atom which makes the longest Mo—S bond at 2.1908 (14) Å is involved in three N—H···S bonds, two of which are singly shared. S4 also makes the shortest singly shared N—H···S bond at 2.37 Å, which can explain the elongation of this bond. In contrast, S1 atom involved in the shortest Mo—S bond makes a bifurcated N—H···S bond at a longer S···H distance accompanied by a small NH—S angle. S1 also makes a very weak C—H···S contact. The observed difference Δ between the longest and the shortest Mo—S bond of 0.0326 Å in (I) is shorter than the Δ value of 0.0422 Å in the tetrathiomolybdate compound containing the R-form of the monoprotonated isomeric chiral primary amine 1-phenylethanamine (Srinivasan, Naik et al., 2007).

Related literature

Previous reports give details of the structural characterization of several organic ammonium tetrathiomolybdates derived from organic diamines (Srinivasan et al., 2001; Srinivasan, Dhuri et al., 2005; Srinivasan, Näther & Bensch, 2005), chiral amines (Srinivasan, Naik et al., 2007), triamines (Srinivasan, Dhuri et al., 2007), cyclic amines (Srinivasan, Näther & Bensch, 2006), a tetraamine (Srinivasan et al., 2004) and a primary amine (Srinivasan, Näther et al., 2006).

S2. Experimental

(NH₄)₂[MoS₄] (520 mg, 2 mmol) was dissolved in water (15 ml) containing a few drops of liquor ammonia. To this mixture N-methyl-1-phenylmethanamine (1 ml) was added and the reaction mixture filtered and left in the refrigerator for crystallization. After two days small needles of the title compound separated. The crystals were filtered, washed with ice-cold water (2 ml), followed by 2-propanol (10 ml) and diethyl ether (10 ml) and dried. Yield: 60%.

S3. Refinement

The H atoms were positioned with idealized geometry (C—H = 0.93 (aromatic), O.96 (methyl) and 0.97 (benzilic) Å and N—H = 0.90 Å) and were refined using a riding model, with U_iso(H) fixed at 1.5U_eq(CH₃) and 1.2U_eq(NH₂, benzilic, aromatic).

Computing details

Data collection: SMART (Bruker, 2001); cell refinement: SAINT (Bruker, 2001); data reduction: SAINT (Bruker, 2001); program(s) used to solve structure: SHELXTL (Sheldrick, 2001); program(s) used to refine structure: SHELXTL (Sheldrick, 2001); molecular graphics: DIAMOND (Brandenburg 1999); software used to prepare material for publication: SHELXTL (Sheldrick, 2001).

Figures

	Fig. 1. The crystal structure of (I) showing the atom-labelling scheme. Displacement ellipsoids are drawn at the 30% probability level.
	Fig. 2. A view of the surroundings of the [MoS4]^2- anion showing its linking to five different organic cations with the aid of six N—H···S and two C—H···S interactions. N—H···S and C—H···S interactions are shown as dashed lines and dotted lines respectively. Symmetry codes: (i) x + 1, y, z (ii) -x + 1, -y + 1, -z + 1; (iii) -x, -y + 1, z - 1

Bis[benzyl(methyl)ammonium] tetrathiomolybdate(VI)

Crystal data

(C8H12N)2[MoS4]	Z = 2
Mr = 468.55	F(000) = 480
Triclinic, P1	Dx = 1.480 Mg m^−3
Hall symbol: -P 1	Mo Kα radiation, λ = 0.71073 Å
a = 7.1857 (12) Å	Cell parameters from 4674 reflections
b = 10.7376 (18) Å	θ = 2.9–25.9°
c = 14.881 (2) Å	µ = 1.02 mm^−1
α = 110.811 (2)°	T = 298 K
β = 90.608 (3)°	Thin nedle, red
γ = 100.504 (3)°	0.42 × 0.06 × 0.02 mm
V = 1051.7 (3) Å^3

Data collection

Bruker SMART APEX CCD diffractometer	3639 independent reflections
Radiation source: fine-focus sealed tube	3015 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.035
φ and ω scans	θmax = 25.0°, θmin = 1.5°
Absorption correction: multi-scan (SADABS; Sheldrick, 2004)	h = −8→8
Tmin = 0.901, Tmax = 0.976	k = −12→11
7363 measured reflections	l = −17→17

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)] = 0.050	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.100	H-atom parameters constrained
S = 1.05	w = 1/[σ^2(Fo^2) + (0.0387P)^2 + 0.9757P] where P = (Fo^2 + 2Fc^2)/3
3639 reflections	(Δ/σ)max < 0.001
210 parameters	Δρmax = 0.68 e Å^−3
0 restraints	Δρmin = −0.51 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
C1	0.5906 (7)	0.4755 (6)	0.1061 (3)	0.0448 (13)
C2	0.7203 (8)	0.4231 (7)	0.0439 (4)	0.0575 (15)
H2	0.8260	0.4816	0.0361	0.069*
C3	0.6971 (11)	0.2869 (8)	−0.0068 (4)	0.0714 (19)
H3	0.7854	0.2531	−0.0493	0.086*
C4	0.5436 (12)	0.2006 (7)	0.0055 (5)	0.077 (2)
H4	0.5279	0.1075	−0.0283	0.092*
C5	0.4126 (10)	0.2507 (7)	0.0674 (5)	0.075 (2)
H5	0.3075	0.1918	0.0753	0.090*
C6	0.4366 (8)	0.3879 (7)	0.1177 (4)	0.0592 (16)
H6	0.3478	0.4217	0.1600	0.071*
C7	0.6150 (8)	0.6270 (6)	0.1585 (4)	0.0510 (14)
H7A	0.7090	0.6734	0.1287	0.061*
H7B	0.4957	0.6545	0.1521	0.061*
C8	0.6958 (8)	0.8155 (5)	0.3161 (4)	0.0573 (15)
H8A	0.7718	0.8658	0.2829	0.086*
H8B	0.7565	0.8372	0.3791	0.086*
H8C	0.5728	0.8392	0.3223	0.086*
C9	0.1099 (7)	0.1225 (5)	0.2958 (4)	0.0401 (12)
C10	0.0895 (8)	0.0024 (6)	0.2183 (4)	0.0528 (14)
H10	0.1464	−0.0669	0.2221	0.063*
C11	−0.0153 (9)	−0.0155 (7)	0.1348 (5)	0.0677 (18)
H11	−0.0323	−0.0979	0.0831	0.081*
C12	−0.0937 (9)	0.0877 (7)	0.1282 (4)	0.0682 (18)
H12	−0.1609	0.0765	0.0712	0.082*
C13	−0.0739 (8)	0.2073 (6)	0.2050 (4)	0.0583 (16)
H13	−0.1285	0.2773	0.2006	0.070*
C14	0.0269 (8)	0.2240 (5)	0.2887 (4)	0.0494 (14)
H14	0.0389	0.3052	0.3411	0.059*
C15	0.2213 (8)	0.1417 (6)	0.3879 (4)	0.0511 (14)
H15A	0.1415	0.1651	0.4412	0.061*
H15B	0.2585	0.0571	0.3826	0.061*
C16	0.5316 (8)	0.2289 (7)	0.3349 (4)	0.0640 (17)
H16A	0.5654	0.1422	0.3224	0.096*
H16B	0.6432	0.2994	0.3579	0.096*
H16C	0.4767	0.2309	0.2764	0.096*
Mo1	0.16547 (6)	0.66475 (4)	0.38214 (3)	0.03200 (14)
N1	0.6748 (6)	0.6684 (4)	0.2609 (3)	0.0443 (10)
H1A	0.7867	0.6441	0.2662	0.053*
H1B	0.5892	0.6228	0.2875	0.053*
N2	0.3937 (6)	0.2507 (5)	0.4080 (3)	0.0563 (13)
H2A	0.3565	0.3291	0.4152	0.068*
H2B	0.4529	0.2612	0.4645	0.068*
S1	−0.10243 (18)	0.57324 (14)	0.41788 (10)	0.0458 (3)
S2	0.2566 (2)	0.86869 (15)	0.48604 (12)	0.0619 (4)
S3	0.1321 (2)	0.66870 (17)	0.23687 (10)	0.0552 (4)
S4	0.37925 (19)	0.54486 (14)	0.38649 (10)	0.0466 (3)

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
C1	0.045 (3)	0.060 (4)	0.033 (3)	0.018 (3)	−0.001 (2)	0.018 (3)
C2	0.056 (4)	0.068 (4)	0.051 (3)	0.018 (3)	0.006 (3)	0.023 (3)
C3	0.087 (5)	0.083 (5)	0.050 (4)	0.043 (4)	0.008 (4)	0.020 (4)
C4	0.118 (7)	0.055 (4)	0.058 (4)	0.030 (5)	−0.016 (4)	0.014 (4)
C5	0.080 (5)	0.067 (5)	0.064 (4)	−0.006 (4)	−0.009 (4)	0.017 (4)
C6	0.051 (4)	0.070 (5)	0.049 (3)	0.008 (3)	0.008 (3)	0.014 (3)
C7	0.052 (4)	0.061 (4)	0.047 (3)	0.015 (3)	0.001 (3)	0.026 (3)
C8	0.058 (4)	0.044 (4)	0.065 (4)	0.008 (3)	0.010 (3)	0.014 (3)
C9	0.034 (3)	0.044 (3)	0.043 (3)	0.007 (2)	0.008 (2)	0.019 (3)
C10	0.052 (4)	0.038 (3)	0.065 (4)	0.013 (3)	0.005 (3)	0.013 (3)
C11	0.069 (4)	0.055 (4)	0.056 (4)	0.010 (3)	−0.004 (3)	−0.006 (3)
C12	0.061 (4)	0.089 (5)	0.049 (4)	0.019 (4)	−0.008 (3)	0.017 (4)
C13	0.046 (4)	0.063 (4)	0.073 (4)	0.022 (3)	0.003 (3)	0.028 (4)
C14	0.047 (3)	0.038 (3)	0.056 (3)	0.009 (3)	−0.002 (3)	0.008 (3)
C15	0.058 (4)	0.054 (4)	0.045 (3)	0.012 (3)	0.007 (3)	0.022 (3)
C16	0.041 (3)	0.083 (5)	0.070 (4)	0.009 (3)	0.004 (3)	0.031 (4)
Mo1	0.0265 (2)	0.0333 (3)	0.0379 (2)	0.00674 (17)	0.00297 (17)	0.01470 (19)
N1	0.041 (3)	0.044 (3)	0.047 (3)	0.009 (2)	0.002 (2)	0.014 (2)
N2	0.051 (3)	0.068 (3)	0.046 (3)	0.017 (3)	−0.005 (2)	0.015 (2)
S1	0.0340 (7)	0.0519 (9)	0.0577 (8)	0.0090 (6)	0.0102 (6)	0.0271 (7)
S2	0.0690 (11)	0.0358 (8)	0.0698 (10)	0.0050 (8)	−0.0012 (8)	0.0087 (8)
S3	0.0500 (9)	0.0818 (12)	0.0498 (8)	0.0243 (8)	0.0121 (7)	0.0375 (8)
S4	0.0360 (8)	0.0492 (9)	0.0594 (9)	0.0137 (6)	0.0021 (6)	0.0230 (7)

Geometric parameters (Å, º)

C1—C2	1.371 (7)	C10—H10	0.9300
C1—C6	1.372 (7)	C11—C12	1.363 (9)
C1—C7	1.509 (7)	C11—H11	0.9300
C2—C3	1.364 (8)	C12—C13	1.365 (8)
C2—H2	0.9300	C12—H12	0.9300
C3—C4	1.364 (9)	C13—C14	1.372 (7)
C3—H3	0.9300	C13—H13	0.9300
C4—C5	1.370 (9)	C14—H14	0.9300
C4—H4	0.9300	C15—N2	1.487 (7)
C5—C6	1.372 (8)	C15—H15A	0.9700
C5—H5	0.9300	C15—H15B	0.9700
C6—H6	0.9300	C16—N2	1.465 (7)
C7—N1	1.463 (6)	C16—H16A	0.9600
C7—H7A	0.9700	C16—H16B	0.9600
C7—H7B	0.9700	C16—H16C	0.9600
C8—N1	1.477 (6)	Mo1—S1	2.1582 (13)
C8—H8A	0.9600	Mo1—S2	2.1597 (16)
C8—H8B	0.9600	Mo1—S3	2.1888 (14)
C8—H8C	0.9600	Mo1—S4	2.1908 (14)
C9—C14	1.369 (7)	N1—H1A	0.9000
C9—C10	1.372 (7)	N1—H1B	0.9000
C9—C15	1.509 (7)	N2—H2A	0.9000
C10—C11	1.380 (8)	N2—H2B	0.9000
C2—C1—C6	118.7 (6)	C11—C12—C13	120.2 (6)
C2—C1—C7	120.4 (5)	C11—C12—H12	119.9
C6—C1—C7	120.9 (5)	C13—C12—H12	119.9
C3—C2—C1	121.3 (6)	C12—C13—C14	119.8 (6)
C3—C2—H2	119.4	C12—C13—H13	120.1
C1—C2—H2	119.4	C14—C13—H13	120.1
C4—C3—C2	119.6 (6)	C9—C14—C13	120.7 (5)
C4—C3—H3	120.2	C9—C14—H14	119.6
C2—C3—H3	120.2	C13—C14—H14	119.6
C3—C4—C5	120.1 (7)	N2—C15—C9	111.2 (4)
C3—C4—H4	119.9	N2—C15—H15A	109.4
C5—C4—H4	119.9	C9—C15—H15A	109.4
C4—C5—C6	119.9 (7)	N2—C15—H15B	109.4
C4—C5—H5	120.0	C9—C15—H15B	109.4
C6—C5—H5	120.0	H15A—C15—H15B	108.0
C5—C6—C1	120.4 (6)	N2—C16—H16A	109.5
C5—C6—H6	119.8	N2—C16—H16B	109.5
C1—C6—H6	119.8	H16A—C16—H16B	109.5
N1—C7—C1	112.2 (4)	N2—C16—H16C	109.5
N1—C7—H7A	109.2	H16A—C16—H16C	109.5
C1—C7—H7A	109.2	H16B—C16—H16C	109.5
N1—C7—H7B	109.2	S1—Mo1—S2	109.43 (6)
C1—C7—H7B	109.2	S1—Mo1—S3	109.32 (6)
H7A—C7—H7B	107.9	S2—Mo1—S3	110.28 (7)
N1—C8—H8A	109.5	S1—Mo1—S4	109.47 (5)
N1—C8—H8B	109.5	S2—Mo1—S4	109.01 (6)
H8A—C8—H8B	109.5	S3—Mo1—S4	109.31 (6)
N1—C8—H8C	109.5	C7—N1—C8	114.4 (4)
H8A—C8—H8C	109.5	C7—N1—H1A	108.7
H8B—C8—H8C	109.5	C8—N1—H1A	108.7
C14—C9—C10	119.2 (5)	C7—N1—H1B	108.7
C14—C9—C15	120.5 (5)	C8—N1—H1B	108.7
C10—C9—C15	120.3 (5)	H1A—N1—H1B	107.6
C9—C10—C11	120.1 (5)	C16—N2—C15	116.1 (5)
C9—C10—H10	119.9	C16—N2—H2A	108.3
C11—C10—H10	119.9	C15—N2—H2A	108.3
C12—C11—C10	119.9 (6)	C16—N2—H2B	108.3
C12—C11—H11	120.0	C15—N2—H2B	108.3
C10—C11—H11	120.0	H2A—N2—H2B	107.4

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
N1—H1A···S3^i	0.90	2.51	3.308 (4)	149
N1—H1A···S1^i	0.90	2.78	3.358 (4)	124
N1—H1B···S4	0.90	2.37	3.253 (4)	168
N2—H2A···S4	0.90	2.48	3.305 (5)	153
N2—H2B···S4^ii	0.90	2.54	3.264 (5)	138
N2—H2B···S2^ii	0.90	2.93	3.602 (5)	132
C7—H7B···S3	0.97	2.92	3.727 (6)	141
C15—H15A···S1^iii	0.97	2.91	3.629 (6)	132

Symmetry codes: (i) x+1, y, z; (ii) −x+1, −y+1, −z+1; (iii) −x, −y+1, −z+1.