(RS)-Tricarbon-yl(η-1,3-diacet-oxy-5,5-dimethyl-cyclo-hexa-1,3-diene)iron(0).

In the title compound, [Fe(C(12)H(16)O(4))(CO)(3)], the diene moiety of the mol-ecule is virtually planar, with a C-C-C-C torsion angle of -1.4 (2)°. The six-membered ring exhibits a boat conformation, with torsion angles of 46.2 (2) and 46.5 (3)° for a double-bond and the two attached Csp(3) atoms. The Fe atom is coordinated to all four of the diene C atoms, with bond lengths between 2.041 (2) and 2.117 (2) Å. The Fe(CO)(3) tripod adopts a conformation with one CO ligand eclipsing the Csp(3)-Csp(3) single bond.

Related literature

For a short overview of CO as a signaling mol­ecule and of CO-releasing mol­ecules (CO-RMs), see: Choi & Otterbein (2002 ▶); Johnson et al. (2003 ▶); Alberto & Motterlini (2007 ▶); Mann & Motterlini (2007 ▶). For a very recent review of the biological activity of carbon monoxide gas and CO-RMs, see: Motterlini & Otterbein (2010 ▶). For the first use of the title compound as a CO-RM, see: Romanski et al. (2011 ▶). For a known synthesis of this mol­ecule in racemic form, see: Boháč et al. (1996 ▶). For a description of the Cambridge Structural Database, see: Allen (2002 ▶).

Experimental

Crystal data

[Fe(C12H16O4)(CO)3]

M = 364.13

Monoclinic,

a = 10.9977 (6) Å

b = 11.9586 (5) Å

c = 13.0364 (5) Å

β = 108.739 (3)°

V = 1623.63 (13) Å3

Z = 4

Mo Kα radiation

μ = 0.96 mm−1

T = 100 K

0.30 × 0.15 × 0.07 mm

Data collection

Nonius KappaCCD diffractometer

Absorption correction: multi-scan (PLATON; Spek, 2009 ▶) T min = 0.700, T max = 0.931

15588 measured reflections

3538 independent reflections

2814 reflections with I > 2σ(I)

R int = 0.059

Refinement

R[F 2 > 2σ(F 2)] = 0.031

wR(F 2) = 0.078

S = 1.06

3538 reflections

212 parameters

H-atom parameters constrained

Δρmax = 0.66 e Å−3

Δρmin = −0.62 e Å−3

Data collection: COLLECT (Hooft, 1998 ▶); cell refinement: DENZO (Otwinowski & Minor, 1997 ▶); data reduction: DENZO; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: SCHAKAL99 (Keller, 1999 ▶); software used to prepare material for publication: PLATON (Spek, 2009 ▶).

Crystal structure: contains datablock(s) global, I. DOI: 10.1107/S1600536811041298/rk2295sup1.cif

Structure factors: contains datablock(s) I. DOI: 10.1107/S1600536811041298/rk2295Isup2.hkl

Additional supplementary materials: crystallographic information; 3D view; checkCIF report

[Fe(C12H16O4)(CO)3]	F(000) = 752
Mr = 364.13	Dx = 1.490 Mg m−3
Monoclinic, P21/c	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ybc	Cell parameters from 15588 reflections
a = 10.9977 (6) Å	θ = 2.0–27.0°
b = 11.9586 (5) Å	µ = 0.96 mm−1
c = 13.0364 (5) Å	T = 100 K
β = 108.739 (3)°	Prism, colourless
V = 1623.63 (13) Å3	0.3 × 0.15 × 0.07 mm
Z = 4

Nonius KappaCCD diffractometer	3538 independent reflections
Radiation source: fine–focus sealed tube	2814 reflections with I > 2σ(I)
graphite	Rint = 0.059
φ and ω scans	θmax = 27.0°, θmin = 2.0°
Absorption correction: multi-scan (PLATON; Spek, 2009)	h = −14→13
Tmin = 0.700, Tmax = 0.931	k = −14→15
15588 measured reflections	l = −16→16

Refinement on F2	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F2 > 2σ(F2)] = 0.031	Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.078	H-atom parameters constrained
S = 1.06	w = 1/[σ2(Fo2) + (0.0353P)2 + 0.1094P] where P = (Fo2 + 2Fc2)/3
3538 reflections	(Δ/σ)max = 0.001
212 parameters	Δρmax = 0.66 e Å−3
0 restraints	Δρmin = −0.62 e Å−3

Geometry. All s.u.'s (except the s.u. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell s.u.'s are taken into account individually in the estimation of s.u.'s in distances, angles and torsion angles; correlations between s.u.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell s.u.'s is used for estimating s.u.'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.

	x	y	z	Uiso*/Ueq
Fe1	0.66661 (3)	0.30437 (2)	0.424274 (19)	0.01185 (9)
O1	0.94976 (13)	0.27963 (10)	0.43516 (10)	0.0147 (3)
O2	0.86658 (15)	0.20345 (11)	0.26861 (10)	0.0227 (3)
O3	0.68135 (13)	0.47430 (10)	0.60010 (9)	0.0141 (3)
O4	0.86120 (14)	0.57754 (12)	0.67162 (11)	0.0229 (3)
O5	0.41698 (15)	0.28056 (11)	0.46063 (11)	0.0204 (3)
O6	0.75961 (16)	0.08729 (12)	0.52412 (12)	0.0301 (4)
O7	0.57537 (14)	0.24054 (12)	0.19457 (10)	0.0220 (3)
C1	0.84627 (19)	0.35591 (15)	0.42037 (14)	0.0126 (4)
C2	0.8298 (2)	0.38305 (15)	0.52183 (14)	0.0142 (4)
H2	0.8865	0.3589	0.5898	0.017*
C3	0.72175 (19)	0.44864 (15)	0.51032 (14)	0.0127 (4)
C4	0.64858 (19)	0.47985 (15)	0.40352 (13)	0.0123 (4)
H4	0.5576	0.4736	0.3789	0.015*
C5	0.72083 (19)	0.52401 (15)	0.32899 (14)	0.0141 (4)
C6	0.8340 (2)	0.44474 (15)	0.33460 (14)	0.0152 (4)
H6A	0.8193	0.4087	0.2633	0.018*
H6B	0.9147	0.4883	0.3523	0.018*
C7	0.6296 (2)	0.53454 (16)	0.21245 (14)	0.0180 (4)
H7A	0.5586	0.5847	0.2110	0.027*
H7B	0.5955	0.4606	0.1856	0.027*
H7C	0.6765	0.5650	0.1663	0.027*
C8	0.7709 (2)	0.64176 (16)	0.37013 (16)	0.0202 (5)
H8A	0.6988	0.6890	0.3720	0.030*
H8B	0.8126	0.6750	0.3213	0.030*
H8C	0.8331	0.6360	0.4432	0.030*
C9	0.9517 (2)	0.20967 (15)	0.35318 (15)	0.0174 (4)
C10	1.0733 (2)	0.14411 (19)	0.38555 (17)	0.0262 (5)
H10A	1.0677	0.0849	0.3323	0.039*
H10B	1.0869	0.1106	0.4570	0.039*
H10C	1.1453	0.1937	0.3887	0.039*
C11	0.7642 (2)	0.53864 (15)	0.67896 (14)	0.0153 (4)
C12	0.7140 (2)	0.55145 (17)	0.77265 (14)	0.0194 (5)
H12A	0.6339	0.5944	0.7496	0.029*
H12B	0.7777	0.5909	0.8318	0.029*
H12C	0.6977	0.4774	0.7977	0.029*
C13	0.5151 (2)	0.29061 (15)	0.44952 (14)	0.0148 (4)
C14	0.7219 (2)	0.17132 (17)	0.48471 (15)	0.0186 (5)
C15	0.6127 (2)	0.26595 (16)	0.28408 (15)	0.0157 (4)

	U11	U22	U33	U12	U13	U23
Fe1	0.01399 (17)	0.01153 (15)	0.01009 (14)	0.00017 (12)	0.00396 (11)	−0.00037 (10)
O1	0.0157 (8)	0.0155 (7)	0.0131 (6)	0.0044 (6)	0.0049 (6)	−0.0016 (5)
O2	0.0245 (9)	0.0251 (8)	0.0161 (7)	0.0045 (7)	0.0034 (6)	−0.0063 (6)
O3	0.0159 (8)	0.0169 (7)	0.0107 (6)	−0.0001 (6)	0.0061 (5)	−0.0034 (5)
O4	0.0199 (9)	0.0266 (8)	0.0235 (7)	−0.0063 (7)	0.0088 (6)	−0.0079 (6)
O5	0.0189 (9)	0.0234 (8)	0.0205 (7)	−0.0015 (6)	0.0083 (6)	−0.0010 (6)
O6	0.0403 (11)	0.0190 (9)	0.0315 (8)	0.0094 (8)	0.0124 (8)	0.0088 (7)
O7	0.0239 (9)	0.0271 (8)	0.0131 (7)	−0.0021 (7)	0.0032 (6)	−0.0037 (6)
C1	0.0101 (11)	0.0124 (10)	0.0141 (9)	0.0013 (8)	0.0024 (8)	−0.0006 (7)
C2	0.0142 (11)	0.0138 (10)	0.0128 (9)	−0.0026 (8)	0.0019 (8)	−0.0025 (7)
C3	0.0157 (11)	0.0109 (10)	0.0127 (9)	−0.0035 (8)	0.0062 (8)	−0.0036 (7)
C4	0.0108 (11)	0.0120 (10)	0.0131 (9)	−0.0037 (8)	0.0023 (8)	−0.0016 (7)
C5	0.0157 (11)	0.0134 (10)	0.0139 (9)	0.0007 (8)	0.0060 (8)	0.0007 (7)
C6	0.0163 (12)	0.0156 (10)	0.0144 (9)	−0.0014 (8)	0.0060 (8)	−0.0001 (7)
C7	0.0204 (12)	0.0198 (11)	0.0155 (9)	0.0033 (9)	0.0081 (8)	0.0036 (8)
C8	0.0229 (13)	0.0160 (11)	0.0246 (11)	−0.0028 (9)	0.0115 (9)	0.0002 (8)
C9	0.0233 (13)	0.0142 (11)	0.0171 (10)	0.0022 (9)	0.0098 (9)	−0.0005 (8)
C10	0.0265 (14)	0.0272 (12)	0.0244 (11)	0.0099 (10)	0.0075 (10)	−0.0038 (9)
C11	0.0189 (12)	0.0124 (10)	0.0129 (9)	0.0026 (8)	0.0030 (8)	−0.0010 (7)
C12	0.0244 (13)	0.0212 (11)	0.0137 (9)	−0.0005 (9)	0.0076 (9)	−0.0044 (8)
C13	0.0207 (12)	0.0128 (10)	0.0102 (9)	0.0001 (8)	0.0039 (8)	−0.0013 (7)
C14	0.0203 (12)	0.0221 (12)	0.0150 (9)	−0.0026 (9)	0.0081 (8)	−0.0033 (8)
C15	0.0154 (12)	0.0136 (10)	0.0200 (10)	−0.0006 (8)	0.0081 (9)	0.0016 (8)

Fe1—C15	1.7907 (19)	C4—C5	1.533 (2)
Fe1—C14	1.793 (2)	C4—H4	0.9500
Fe1—C13	1.807 (2)	C5—C7	1.533 (3)
Fe1—C3	2.0410 (18)	C5—C8	1.544 (3)
Fe1—C2	2.0632 (19)	C5—C6	1.547 (3)
Fe1—C1	2.086 (2)	C6—H6A	0.9900
Fe1—C4	2.1171 (18)	C6—H6B	0.9900
O1—C9	1.363 (2)	C7—H7A	0.9800
O1—C1	1.423 (2)	C7—H7B	0.9800
O2—C9	1.197 (2)	C7—H7C	0.9800
O3—C11	1.370 (2)	C8—H8A	0.9800
O3—C3	1.413 (2)	C8—H8B	0.9800
O4—C11	1.195 (2)	C8—H8C	0.9800
O5—C13	1.140 (2)	C9—C10	1.490 (3)
O6—C14	1.144 (2)	C10—H10A	0.9800
O7—C15	1.147 (2)	C10—H10B	0.9800
C1—C2	1.429 (2)	C10—H10C	0.9800
C1—C6	1.517 (2)	C11—C12	1.501 (2)
C2—C3	1.391 (3)	C12—H12A	0.9800
C2—H2	0.9500	C12—H12B	0.9800
C3—C4	1.416 (2)	C12—H12C	0.9800
C15—Fe1—C14	100.09 (9)	Fe1—C4—H4	90.6
C15—Fe1—C13	98.05 (9)	C4—C5—C7	110.43 (16)
C14—Fe1—C13	92.40 (9)	C4—C5—C8	107.07 (14)
C15—Fe1—C3	136.08 (8)	C7—C5—C8	108.42 (15)
C14—Fe1—C3	120.64 (8)	C4—C5—C6	109.38 (15)
C13—Fe1—C3	96.05 (8)	C7—C5—C6	110.93 (14)
C15—Fe1—C2	133.11 (8)	C8—C5—C6	110.52 (17)
C14—Fe1—C2	91.64 (8)	C1—C6—C5	110.10 (15)
C13—Fe1—C2	126.85 (8)	C1—C6—H6A	109.6
C3—Fe1—C2	39.62 (7)	C5—C6—H6A	109.6
C15—Fe1—C1	93.24 (8)	C1—C6—H6B	109.6
C14—Fe1—C1	94.73 (8)	C5—C6—H6B	109.6
C13—Fe1—C1	165.38 (8)	H6A—C6—H6B	108.2
C3—Fe1—C1	69.34 (7)	C5—C7—H7A	109.5
C2—Fe1—C1	40.28 (7)	C5—C7—H7B	109.5
C15—Fe1—C4	97.89 (8)	H7A—C7—H7B	109.5
C14—Fe1—C4	160.13 (8)	C5—C7—H7C	109.5
C13—Fe1—C4	93.41 (8)	H7A—C7—H7C	109.5
C3—Fe1—C4	39.77 (7)	H7B—C7—H7C	109.5
C2—Fe1—C4	69.75 (7)	C5—C8—H8A	109.5
C1—Fe1—C4	75.79 (7)	C5—C8—H8B	109.5
C9—O1—C1	120.04 (15)	H8A—C8—H8B	109.5
C11—O3—C3	115.66 (15)	C5—C8—H8C	109.5
O1—C1—C2	110.73 (15)	H8A—C8—H8C	109.5
O1—C1—C6	115.27 (15)	H8B—C8—H8C	109.5
C2—C1—C6	121.04 (16)	O2—C9—O1	123.76 (18)
O1—C1—Fe1	122.01 (12)	O2—C9—C10	126.38 (17)
C2—C1—Fe1	69.01 (11)	O1—C9—C10	109.86 (17)
C6—C1—Fe1	111.37 (13)	C9—C10—H10A	109.5
C3—C2—C1	112.72 (16)	C9—C10—H10B	109.5
C3—C2—Fe1	69.33 (11)	H10A—C10—H10B	109.5
C1—C2—Fe1	70.71 (11)	C9—C10—H10C	109.5
C3—C2—H2	123.6	H10A—C10—H10C	109.5
C1—C2—H2	123.6	H10B—C10—H10C	109.5
Fe1—C2—H2	128.1	O4—C11—O3	123.65 (17)
C2—C3—O3	121.22 (16)	O4—C11—C12	126.61 (18)
C2—C3—C4	116.78 (16)	O3—C11—C12	109.74 (17)
O3—C3—C4	121.78 (17)	C11—C12—H12A	109.5
C2—C3—Fe1	71.05 (11)	C11—C12—H12B	109.5
O3—C3—Fe1	121.47 (12)	H12A—C12—H12B	109.5
C4—C3—Fe1	73.01 (10)	C11—C12—H12C	109.5
C3—C4—C5	117.86 (17)	H12A—C12—H12C	109.5
C3—C4—Fe1	67.22 (10)	H12B—C12—H12C	109.5
C5—C4—Fe1	112.09 (12)	O5—C13—Fe1	176.88 (16)
C3—C4—H4	121.1	O6—C14—Fe1	178.7 (2)
C5—C4—H4	121.1	O7—C15—Fe1	178.33 (18)
C9—O1—C1—C2	153.86 (16)	C14—Fe1—C3—O3	−67.18 (18)
C9—O1—C1—C6	−64.1 (2)	C13—Fe1—C3—O3	29.24 (16)
C9—O1—C1—Fe1	76.28 (18)	C2—Fe1—C3—O3	−115.62 (19)
C15—Fe1—C1—C2	172.64 (12)	C1—Fe1—C3—O3	−150.23 (16)
C14—Fe1—C1—C2	−86.95 (12)	C4—Fe1—C3—O3	117.3 (2)
C13—Fe1—C1—C2	32.0 (3)	C15—Fe1—C3—C4	20.20 (17)
C3—Fe1—C1—C2	34.07 (11)	C14—Fe1—C3—C4	175.53 (12)
C4—Fe1—C1—C2	75.32 (11)	C13—Fe1—C3—C4	−88.06 (12)
C15—Fe1—C1—C6	56.35 (13)	C2—Fe1—C3—C4	127.08 (16)
C14—Fe1—C1—C6	156.76 (13)	C1—Fe1—C3—C4	92.47 (12)
C13—Fe1—C1—C6	−84.3 (3)	C2—C3—C4—C5	−46.2 (2)
C3—Fe1—C1—C6	−82.22 (13)	O3—C3—C4—C5	139.23 (17)
C2—Fe1—C1—C6	−116.29 (17)	Fe1—C3—C4—C5	−103.85 (15)
C4—Fe1—C1—C6	−40.97 (12)	C2—C3—C4—Fe1	57.69 (15)
O1—C1—C2—C3	−174.00 (16)	O3—C3—C4—Fe1	−116.92 (17)
C6—C1—C2—C3	46.5 (3)	C15—Fe1—C4—C3	−166.01 (12)
Fe1—C1—C2—C3	−56.50 (14)	C14—Fe1—C4—C3	−11.4 (3)
O1—C1—C2—Fe1	−117.50 (14)	C13—Fe1—C4—C3	95.37 (12)
C6—C1—C2—Fe1	102.98 (17)	C2—Fe1—C4—C3	−32.83 (11)
C15—Fe1—C2—C3	114.62 (13)	C1—Fe1—C4—C3	−74.64 (11)
C14—Fe1—C2—C3	−139.90 (11)	C15—Fe1—C4—C5	−53.89 (14)
C13—Fe1—C2—C3	−45.67 (14)	C14—Fe1—C4—C5	100.7 (2)
C1—Fe1—C2—C3	124.71 (15)	C13—Fe1—C4—C5	−152.51 (13)
C4—Fe1—C2—C3	32.95 (10)	C3—Fe1—C4—C5	112.12 (18)
C15—Fe1—C2—C1	−10.09 (16)	C2—Fe1—C4—C5	79.29 (13)
C14—Fe1—C2—C1	95.39 (11)	C1—Fe1—C4—C5	37.48 (13)
C13—Fe1—C2—C1	−170.38 (11)	C3—C4—C5—C7	170.42 (16)
C3—Fe1—C2—C1	−124.71 (15)	Fe1—C4—C5—C7	95.38 (15)
C4—Fe1—C2—C1	−91.76 (11)	C3—C4—C5—C8	−71.7 (2)
C1—C2—C3—O3	173.19 (16)	Fe1—C4—C5—C8	−146.77 (13)
Fe1—C2—C3—O3	115.93 (16)	C3—C4—C5—C6	48.1 (2)
C1—C2—C3—C4	−1.4 (2)	Fe1—C4—C5—C6	−26.98 (18)
Fe1—C2—C3—C4	−58.71 (15)	O1—C1—C6—C5	−178.32 (15)
C1—C2—C3—Fe1	57.27 (14)	C2—C1—C6—C5	−40.5 (2)
C11—O3—C3—C2	64.8 (2)	Fe1—C1—C6—C5	37.17 (18)
C11—O3—C3—C4	−120.82 (19)	C4—C5—C6—C1	−6.0 (2)
C11—O3—C3—Fe1	150.55 (14)	C7—C5—C6—C1	−128.02 (16)
C15—Fe1—C3—C2	−106.89 (14)	C8—C5—C6—C1	111.68 (17)
C14—Fe1—C3—C2	48.44 (14)	C1—O1—C9—O2	−4.1 (3)
C13—Fe1—C3—C2	144.86 (11)	C1—O1—C9—C10	176.09 (16)
C1—Fe1—C3—C2	−34.61 (10)	C3—O3—C11—O4	4.5 (3)
C4—Fe1—C3—C2	−127.08 (16)	C3—O3—C11—C12	−175.53 (15)
C15—Fe1—C3—O3	137.49 (15)