Tetra­kis(μ-4-chloro­phenoxy­acetato-κ²O,O′)dimolybdenum(II)

The crystal structure determination of the title compound, [Mo₂(C₈H₆ClO₃)₄], confirms the existence of a quadruple bond between the Mo atoms, with an Mo—Mo distance of 2.101 (5) Å. One half of the mol­ecule constitutes the asymmetric unit and the carboxyl­ate ligands define a paddle-wheel structure, with similar O—C—O angles of 122.9 (3) and 123.7 (3)°. The inter­planar angles between the acetate and 4-chloro­phen­oxy planes in the two independent ligands are 135.9 (8) and 91.3 (8)°, which is indicative of a dramatic difference in the orientation of the ligands.

Key indicators

• Single-crystal X-ray study
• T = 293 K
• Mean [sigma](C-C) = 0.005 Å
• R factor = 0.026
• wR factor = 0.063
• Data-to-parameter ratio = 11.1

checkCIF/PLATON results

No syntax errors found



Alert level B
PLAT027_ALERT_3_B _diffrn_reflns_theta_full (too) Low ............      24.96 Deg.
PLAT430_ALERT_2_B Short Inter D...A Contact  O2     ..  O2      ..       2.75 Ang.

Alert level C
PLAT164_ALERT_4_C Nr. of Refined C-H H-Atoms in Heavy-At Struct...         12
PLAT199_ALERT_1_C Check the Reported _cell_measurement_temperature        293 K
PLAT242_ALERT_2_C Check Low       Ueq as Compared to Neighbors for         C6
PLAT350_ALERT_3_C Short   C-H Bond (0.96A)   C4     -   H4     ...       0.79 Ang.
PLAT350_ALERT_3_C Short   C-H Bond (0.96A)   C5     -   H5     ...       0.82 Ang.
PLAT350_ALERT_3_C Short   C-H Bond (0.96A)   C8     -   H8     ...       0.83 Ang.

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

   1 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
   4 ALERT type 3 Indicator that the structure quality may be low
   1 ALERT type 4 Improvement, methodology, query or suggestion

---

Computing details

Data collection: CAD-4 EXPRESS (Enraf–Nonius, 1994); cell refinement: CAD-4 EXPRESS; data reduction: XCAD4 (Harms & Wocadlo, 1995); program(s) used to solve structure: SIR97 (Altomare et al., 1999); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: ORTEP-3 for Windows (Farrugia, 1997); software used to prepare material for publication: WinGX (Farrugia, 1999).

Tetrakis(µ-4-chlorophenoxyacetato-κ²O,O')dimolybdenum(II)

Crystal data

[Mo2(C8H6ClO3)4]	Z = 1
Mr = 934.19	F(000) = 464
Triclinic, P1	Dx = 1.797 Mg m^−3
Hall symbol: -P 1	Mo Kα radiation, λ = 0.71069 Å
a = 5.668 (1) Å	Cell parameters from 25 reflections
b = 11.549 (1) Å	θ = 10–15°
c = 13.743 (2) Å	µ = 1.10 mm^−1
α = 91.95 (1)°	T = 293 K
β = 101.74 (1)°	Prism, pale red
γ = 100.64 (1)°	0.3 × 0.1 × 0.1 mm
V = 863.3 (2) Å^3

Data collection

Enraf–Nonius TurboCAD-4 diffractometer	Rint = 0.016
non–profiled ω/2θ scans	θmax = 25.0°, θmin = 1.5°
Absorption correction: ψ scan (North et al., 1968)	h = 0→6
Tmin = 0.856, Tmax = 0.895	k = −13→13
3374 measured reflections	l = −16→15
3036 independent reflections	3 standard reflections every 166 min
2657 reflections with I > 2σ(I)	intensity decay: none

Refinement

Refinement on F^2	0 restraints
Least-squares matrix: full	All H-atom parameters refined
R[F^2 > 2σ(F^2)] = 0.026	w = 1/[σ^2(Fo^2) + (0.0257P)^2 + 0.59P] where P = (Fo^2 + 2Fc^2)/3
wR(F^2) = 0.063	(Δ/σ)max = 0.004
S = 1.04	Δρmax = 0.62 e Å^−3
3036 reflections	Δρmin = −0.47 e Å^−3
274 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
C1	0.3199 (5)	0.1942 (2)	−0.0341 (2)	0.0334 (6)
C2	0.4872 (6)	0.3051 (3)	−0.0510 (3)	0.0422 (8)
C3	0.7827 (5)	0.3718 (3)	−0.1468 (2)	0.0364 (7)
C4	0.7985 (7)	0.4885 (3)	−0.1170 (3)	0.0505 (9)
C5	0.9518 (7)	0.5762 (3)	−0.1528 (3)	0.0588 (10)
C6	1.0877 (6)	0.5472 (3)	−0.2171 (3)	0.0492 (8)
C7	1.0712 (7)	0.4314 (3)	−0.2489 (3)	0.0547 (9)
C8	0.9188 (7)	0.3437 (3)	−0.2135 (3)	0.0491 (8)
C9	−0.1150 (6)	−0.0730 (3)	−0.1957 (2)	0.0381 (7)
C10	−0.1788 (8)	−0.1210 (3)	−0.3041 (3)	0.0518 (9)
C11	−0.0945 (6)	0.0535 (3)	−0.3872 (2)	0.0434 (7)
C12	0.1502 (6)	0.0770 (3)	−0.3399 (3)	0.0490 (8)
C13	0.3061 (8)	0.1723 (4)	−0.3645 (3)	0.0600 (10)
C14	0.2193 (8)	0.2435 (3)	−0.4344 (3)	0.0637 (11)
C15	−0.0253 (9)	0.2221 (4)	−0.4813 (3)	0.0626 (11)
C16	−0.1819 (8)	0.1271 (4)	−0.4582 (3)	0.0535 (9)
O4	−0.2364 (4)	−0.00369 (18)	−0.16549 (15)	0.0382 (5)
O5	0.0604 (4)	−0.10905 (18)	−0.13974 (15)	0.0378 (5)
O6	−0.2654 (4)	−0.0395 (2)	−0.37040 (16)	0.0515 (6)
O1	0.1003 (3)	0.20143 (17)	−0.03518 (15)	0.0357 (5)
O2	0.4019 (3)	0.09980 (17)	−0.01690 (15)	0.0343 (4)
O3	0.6387 (4)	0.27830 (18)	−0.11428 (17)	0.0444 (5)
Cl1	1.2911 (2)	0.65818 (10)	−0.25803 (10)	0.0864 (4)
Cl2	0.4170 (3)	0.36302 (12)	−0.46626 (13)	0.1121 (5)
Mo1	−0.14071 (4)	0.04903 (2)	−0.011244 (19)	0.02837 (9)
H4	0.730 (7)	0.507 (3)	−0.076 (3)	0.058 (12)*
H5	0.961 (8)	0.646 (4)	−0.135 (3)	0.080 (14)*
H7	1.175 (7)	0.416 (3)	−0.293 (3)	0.070 (12)*
H8	0.906 (6)	0.273 (3)	−0.232 (3)	0.047 (10)*
H12	0.213 (6)	0.026 (3)	−0.294 (3)	0.048 (10)*
H13	0.458 (8)	0.186 (3)	−0.332 (3)	0.062 (12)*
H14	−0.094 (8)	0.274 (4)	−0.524 (3)	0.075 (13)*
H15	−0.334 (8)	0.110 (4)	−0.488 (3)	0.069 (13)*
H2A	0.583 (6)	0.341 (3)	0.015 (3)	0.045 (9)*
H2B	0.399 (7)	0.358 (3)	−0.079 (3)	0.053 (10)*
H10A	−0.309 (7)	−0.186 (3)	−0.312 (3)	0.053 (10)*
H10B	−0.036 (7)	−0.148 (3)	−0.321 (3)	0.058 (11)*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
C1	0.0288 (15)	0.0302 (15)	0.0436 (16)	0.0058 (12)	0.0130 (13)	0.0060 (12)
C2	0.0359 (17)	0.0327 (16)	0.064 (2)	0.0066 (14)	0.0232 (16)	0.0095 (16)
C3	0.0327 (15)	0.0338 (16)	0.0431 (17)	0.0033 (12)	0.0114 (13)	0.0088 (13)
C4	0.049 (2)	0.0381 (19)	0.073 (2)	0.0048 (15)	0.0344 (19)	0.0055 (17)
C5	0.057 (2)	0.035 (2)	0.089 (3)	0.0036 (17)	0.031 (2)	0.0109 (19)
C6	0.0429 (19)	0.049 (2)	0.058 (2)	0.0035 (15)	0.0174 (16)	0.0214 (17)
C7	0.056 (2)	0.065 (2)	0.049 (2)	0.0054 (18)	0.0279 (18)	0.0084 (18)
C8	0.053 (2)	0.043 (2)	0.053 (2)	0.0027 (16)	0.0224 (17)	−0.0009 (16)
C9	0.0389 (17)	0.0381 (16)	0.0373 (16)	0.0010 (14)	0.0135 (14)	0.0072 (13)
C10	0.059 (2)	0.052 (2)	0.0410 (19)	0.0004 (19)	0.0136 (17)	0.0037 (16)
C11	0.0486 (19)	0.0507 (19)	0.0324 (16)	0.0077 (15)	0.0146 (14)	−0.0002 (14)
C12	0.044 (2)	0.062 (2)	0.0421 (19)	0.0111 (17)	0.0116 (16)	0.0043 (17)
C13	0.050 (2)	0.067 (3)	0.063 (2)	0.003 (2)	0.019 (2)	0.000 (2)
C14	0.079 (3)	0.049 (2)	0.071 (3)	0.005 (2)	0.042 (2)	0.0027 (19)
C15	0.085 (3)	0.059 (2)	0.057 (2)	0.028 (2)	0.030 (2)	0.0161 (19)
C16	0.057 (2)	0.068 (3)	0.0379 (19)	0.019 (2)	0.0089 (18)	0.0026 (17)
O4	0.0351 (11)	0.0437 (12)	0.0373 (11)	0.0094 (9)	0.0091 (9)	0.0078 (9)
O5	0.0379 (11)	0.0372 (11)	0.0421 (12)	0.0082 (9)	0.0162 (10)	0.0038 (9)
O6	0.0466 (13)	0.0644 (15)	0.0372 (12)	−0.0010 (12)	0.0047 (10)	0.0068 (11)
O1	0.0297 (11)	0.0306 (10)	0.0517 (12)	0.0087 (8)	0.0159 (9)	0.0115 (9)
O2	0.0254 (10)	0.0324 (10)	0.0499 (12)	0.0080 (8)	0.0158 (9)	0.0105 (9)
O3	0.0427 (12)	0.0305 (11)	0.0665 (15)	0.0026 (9)	0.0306 (11)	0.0059 (10)
Cl1	0.0746 (7)	0.0733 (7)	0.1229 (10)	0.0022 (6)	0.0518 (7)	0.0493 (7)
Cl2	0.1253 (12)	0.0721 (8)	0.1529 (14)	−0.0008 (8)	0.0756 (11)	0.0330 (8)
Mo1	0.02287 (13)	0.02914 (13)	0.03674 (14)	0.00697 (9)	0.01212 (9)	0.00842 (9)

Geometric parameters (Å, º)

C1—O1	1.260 (3)	C10—H10A	0.94 (4)
C1—O2	1.273 (3)	C10—H10B	0.98 (4)
C1—C2	1.502 (4)	C11—O6	1.367 (4)
C2—O3	1.405 (4)	C11—C12	1.379 (5)
C2—H2A	0.99 (3)	C11—C16	1.391 (5)
C2—H2B	0.91 (4)	C12—C13	1.376 (5)
C3—O3	1.374 (3)	C12—H12	0.93 (3)
C3—C4	1.377 (5)	C13—C14	1.360 (6)
C3—C8	1.379 (4)	C13—H13	0.87 (4)
C4—C5	1.380 (5)	C14—C15	1.378 (6)
C4—H4	0.80 (4)	C14—Cl2	1.739 (4)
C5—C6	1.356 (5)	C15—C16	1.368 (6)
C5—H5	0.83 (4)	C15—H14	0.94 (4)
C6—C7	1.373 (5)	C16—H15	0.86 (4)
C6—Cl1	1.748 (3)	O4—Mo1	2.117 (2)
C7—C8	1.375 (5)	O5—Mo1^i	2.096 (2)
C7—H7	0.96 (4)	O1—Mo1	2.0991 (19)
C8—H8	0.84 (3)	O2—Mo1^i	2.1529 (19)
C9—O4	1.258 (4)	Mo1—O5^i	2.096 (2)
C9—O5	1.272 (4)	Mo1—Mo1^i	2.1007 (5)
C9—C10	1.519 (5)	Mo1—O2^i	2.1529 (19)
C10—O6	1.415 (4)
O1—C1—O2	122.9 (3)	H10A—C10—H10B	109 (3)
O1—C1—C2	116.5 (3)	O6—C11—C12	124.9 (3)
O2—C1—C2	120.6 (2)	O6—C11—C16	115.4 (3)
O3—C2—C1	109.8 (3)	C12—C11—C16	119.7 (3)
O3—C2—H2A	112.1 (19)	C13—C12—C11	119.6 (4)
C1—C2—H2A	107.4 (19)	C13—C12—H12	120 (2)
O3—C2—H2B	109 (2)	C11—C12—H12	121 (2)
C1—C2—H2B	111 (2)	C14—C13—C12	120.3 (4)
H2A—C2—H2B	107 (3)	C14—C13—H13	122 (3)
O3—C3—C4	124.5 (3)	C12—C13—H13	117 (3)
O3—C3—C8	116.1 (3)	C13—C14—C15	120.9 (4)
C4—C3—C8	119.4 (3)	C13—C14—Cl2	120.2 (4)
C3—C4—C5	120.1 (3)	C15—C14—Cl2	118.9 (3)
C3—C4—H4	121 (3)	C16—C15—C14	119.5 (4)
C5—C4—H4	118 (3)	C16—C15—H14	118 (3)
C6—C5—C4	119.9 (4)	C14—C15—H14	123 (3)
C6—C5—H5	120 (3)	C15—C16—C11	120.1 (4)
C4—C5—H5	120 (3)	C15—C16—H15	122 (3)
C5—C6—C7	120.7 (3)	C11—C16—H15	118 (3)
C5—C6—Cl1	119.7 (3)	C9—O4—Mo1	116.22 (19)
C7—C6—Cl1	119.6 (3)	C9—O5—Mo1^i	116.47 (19)
C6—C7—C8	119.6 (3)	C11—O6—C10	116.8 (3)
C6—C7—H7	117 (2)	C1—O1—Mo1	118.00 (18)
C8—C7—H7	123 (2)	C1—O2—Mo1^i	115.71 (17)
C7—C8—C3	120.2 (3)	C3—O3—C2	117.1 (2)
C7—C8—H8	121 (2)	O5^i—Mo1—O1	87.74 (8)
C3—C8—H8	119 (2)	O5^i—Mo1—Mo1^i	92.03 (6)
O4—C9—O5	123.7 (3)	O1—Mo1—Mo1^i	92.07 (5)
O4—C9—C10	120.1 (3)	O5^i—Mo1—O4	176.38 (8)
O5—C9—C10	116.1 (3)	O1—Mo1—O4	91.45 (8)
O6—C10—C9	113.0 (3)	Mo1^i—Mo1—O4	91.52 (6)
O6—C10—H10A	106 (2)	O5^i—Mo1—O2^i	90.34 (8)
C9—C10—H10A	108 (2)	O1—Mo1—O2^i	176.22 (7)
O6—C10—H10B	112 (2)	Mo1^i—Mo1—O2^i	91.25 (5)
C9—C10—H10B	109 (2)	O4—Mo1—O2^i	90.27 (8)

Symmetry code: (i) −x, −y, −z.