Bromo­penta­carbonyl­manganese

The Mn and Br atoms as well as one of the carbonyl groups of the title compound, [MnBr(CO)₅], are located on a crystallographic mirror plane. As a result, there is just half a mol­ecule in the asymmetric unit displaying C_s symmetry. However, the deviations from C_4v symmetry are very small. BrMn(CO)₅ is isomorphous with ClMn(CO)₅ and CH₃Mn(CO)₅.

Key indicators

• Single-crystal X-ray study
• T = 100 K
• Mean [sigma](O-C) = 0.005 Å
• R factor = 0.032
• wR factor = 0.076
• Data-to-parameter ratio = 15.7

checkCIF/PLATON results

No syntax errors found



Alert level C
PLAT029_ALERT_3_C _diffrn_measured_fraction_theta_full Low .....       0.99
PLAT040_ALERT_1_C No H-atoms in this Carbon Containing Compound           ?
PLAT232_ALERT_2_C Hirshfeld Test Diff (M-X)  Mn1    -   C2     =       5.80 su
PLAT232_ALERT_2_C Hirshfeld Test Diff (M-X)  Mn1    -   C3     =       7.39 su

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

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S1. Comment

The central Mn atom in BrMn(CO)₅ is octahedrally coordinated. The molecule has C_s symmetry. Mn, Br and one of the carbonyl groups are located on a mirror plane perpendicular to the b axis. The deviations from C_4v symmetry are very small. The Mn—C bond trans to the Mn—Br bond is significantly shorter than the equatorial Mn—C bonds. BrMn(CO)₅ is isomorphous with ClMn(CO)₅ (Greene & Bryan, 1971) and CH₃Mn(CO)₅ (Andrews et al., 1983). Unfortunately, the methyl group in the latter structure is statistically disordered over all six coordination sites about the Mn atom.

S2. Experimental

BrMn(CO)₅ was dissolved in C₆D₆ and heated to 353 K for 24 h. When the solution was cooled down to room temperature BrMn(CO)₅ precipitated as yellow crystals.

Computing details

Data collection: X-AREA (Stoe & Cie, 2001); cell refinement: X-AREA; data reduction: X-AREA; program(s) used to solve structure: SHELXS97 (Sheldrick, 1990); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: XP in SHELXTL-Plus (Sheldrick, 1991); software used to prepare material for publication: SHELXL97.

Figures

Fig. 1. Perspective view of the title compound with the atom-numbering scheme; displacement ellipsoids are at the 50% probability level. The symmetry operator for generating equivalent atoms is (i) x, −y + 1/2, z.

Bromopentacarbonylmanganese

Crystal data

[MnBr(CO)5]	F(000) = 520
Mr = 274.90	Dx = 2.295 Mg m^−3
Orthorhombic, Pnma	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ac 2n	Cell parameters from 11620 reflections
a = 11.6252 (16) Å	θ = 3.8–27.6°
b = 11.3317 (18) Å	µ = 6.66 mm^−1
c = 6.0403 (10) Å	T = 100 K
V = 795.7 (2) Å^3	Plate, yellow
Z = 4	0.22 × 0.14 × 0.12 mm

Data collection

Stoe IPDS-II two-circle diffractometer	958 independent reflections
Radiation source: fine-focus sealed tube	772 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.074
ω scans	θmax = 27.6°, θmin = 3.9°
Absorption correction: multi-scan (MULABS; Spek, 1990; Blessing, 1995)	h = −14→15
Tmin = 0.290, Tmax = 0.452	k = −14→14
9213 measured reflections	l = −7→7

Refinement

Refinement on F^2	0 restraints
Least-squares matrix: full	Primary atom site location: structure-invariant direct methods
R[F^2 > 2σ(F^2)] = 0.032	Secondary atom site location: difference Fourier map
wR(F^2) = 0.076	w = 1/[σ^2(Fo^2) + (0.0409P)^2] where P = (Fo^2 + 2Fc^2)/3
S = 1.00	(Δ/σ)max < 0.001
958 reflections	Δρmax = 0.60 e Å^−3
61 parameters	Δρmin = −1.25 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
Mn1	0.37968 (7)	0.2500	0.44786 (13)	0.02054 (19)
Br1	0.25152 (5)	0.2500	0.11225 (8)	0.02419 (16)
O1	0.5319 (3)	0.2500	0.8427 (7)	0.0287 (8)
O2	0.2236 (2)	0.4385 (2)	0.6351 (5)	0.0303 (6)
O3	0.5172 (2)	0.44526 (19)	0.2329 (4)	0.0300 (6)
C1	0.4722 (5)	0.2500	0.6912 (9)	0.0232 (10)
C2	0.2825 (3)	0.3671 (3)	0.5684 (6)	0.0236 (7)
C3	0.4675 (3)	0.3701 (3)	0.3111 (6)	0.0238 (7)

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Mn1	0.0245 (4)	0.0151 (3)	0.0220 (4)	0.000	0.0002 (3)	0.000
Br1	0.0269 (3)	0.0215 (2)	0.0242 (3)	0.000	−0.0019 (2)	0.000
O1	0.0307 (19)	0.0274 (15)	0.0280 (19)	0.000	−0.0032 (18)	0.000
O2	0.0332 (15)	0.0213 (10)	0.0365 (15)	0.0028 (10)	0.0037 (13)	−0.0008 (10)
O3	0.0322 (15)	0.0219 (10)	0.0358 (14)	−0.0026 (10)	0.0022 (13)	0.0033 (10)
C1	0.024 (2)	0.0162 (17)	0.029 (3)	0.000	0.006 (2)	0.000
C2	0.0283 (17)	0.0177 (12)	0.0249 (17)	−0.0050 (13)	−0.0018 (15)	0.0020 (13)
C3	0.0255 (17)	0.0228 (14)	0.0232 (16)	0.0041 (13)	−0.0019 (15)	−0.0050 (13)

Geometric parameters (Å, º)

Mn1—C1	1.821 (6)	Mn1—Br1	2.5158 (10)
Mn1—C2^i	1.889 (4)	O1—C1	1.149 (7)
Mn1—C2	1.889 (4)	O2—C2	1.134 (4)
Mn1—C3^i	1.892 (4)	O3—C3	1.132 (4)
Mn1—C3	1.892 (4)
C1—Mn1—C2^i	92.41 (16)	C3^i—Mn1—C3	92.0 (2)
C1—Mn1—C2	92.41 (16)	C1—Mn1—Br1	179.88 (17)
C2^i—Mn1—C2	89.3 (2)	C2^i—Mn1—Br1	87.51 (11)
C1—Mn1—C3^i	91.93 (16)	C2—Mn1—Br1	87.51 (11)
C2^i—Mn1—C3^i	89.16 (14)	C3^i—Mn1—Br1	88.16 (11)
C2—Mn1—C3^i	175.46 (16)	C3—Mn1—Br1	88.16 (11)
C1—Mn1—C3	91.93 (16)	O1—C1—Mn1	179.0 (5)
C2^i—Mn1—C3	175.46 (16)	O2—C2—Mn1	178.1 (3)
C2—Mn1—C3	89.16 (14)	O3—C3—Mn1	177.2 (3)

Symmetry code: (i) x, −y+1/2, z.