Redetermination of dipotassium μ-oxo-bis­[aqua­(oxalato-κ²O,O′)dioxomolybdate(VI)] at 150 K

The crystal structure of title compound, K₂[Mo₂O₅(C₂O₄)₂(H₂O)₂], originally determined by Cotton, Morehouse & Wood [(1964). Inorg. Chem. pp. 1603–1608], has been redetermined to higher precision and the hydrogen-bonding network elucidated. The anionic [Mo₂O₅(C₂O₄)₂(H₂O)₂]²⁻ complex ion is centrosymmetric with the μ₂-bridging O atom located at the inversion centre.

Key indicators

• Single-crystal X-ray study
• T = 150 K
• Mean [sigma](C-C) = 0.004 Å
• R factor = 0.020
• wR factor = 0.064
• Data-to-parameter ratio = 14.1

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Alert level C
PLAT042_ALERT_1_C Calc. and Rep. MoietyFormula Strings Differ ....          ?
PLAT369_ALERT_2_C Long   C(sp2)-C(sp2) Bond  C3     -   C4     ...       1.56 Ang.
PLAT764_ALERT_4_C Overcomplete CIF Bond List Detected (Rep/Expd) .       2.91 Ratio
PLAT790_ALERT_4_C Centre of Gravity not Within Unit Cell: Resd.  #          2
              K

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Author Response: This crystallographic communication results from a continued research effort in a area for which several researchers contribute with their work and financial support, hence the presence of more than five authors, of which four are supervisors.

   1 ALERT level A = Data missing that is essential or data in wrong format
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Computing details

Data collection: SMART (Bruker 2001); cell refinement: SAINT (Bruker 2001); data reduction: SAINT; program(s) used to solve structure: SHELXTL (Bruker 2001); program(s) used to refine structure: SHELXTL (Bruker 2001); molecular graphics: DIAMOND (Brandenburg, 2006); software used to prepare material for publication: SHELXTL.

dipotassium µ-oxo-bis[aqua(oxalato-κ²O,O')dioxomolybdenum(VI)]

Crystal data

K2[Mo2O5(C2O4)2(H2O)2]	F(000) = 540
Mr = 562.15	Dx = 2.678 Mg m^−3
Monoclinic, P21/c	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ybc	Cell parameters from 9952 reflections
a = 7.4774 (2) Å	θ = 2.7–32.8°
b = 14.2242 (3) Å	µ = 2.48 mm^−1
c = 6.5726 (1) Å	T = 150 K
β = 94.284 (1)°	Prism, colourless
V = 697.11 (3) Å^3	0.40 × 0.27 × 0.20 mm
Z = 2

Data collection

Bruker X8 KappaCCD APEX-II diffractometer	1582 independent reflections
Radiation source: fine-focus sealed tube	1566 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.023
Thin–slice ω and φ scans	θmax = 27.5°, θmin = 4.0°
Absorption correction: multi-scan (SADABS; Sheldrick, 1997)	h = −9→9
Tmin = 0.420, Tmax = 0.612	k = −18→18
28523 measured reflections	l = −8→8

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)] = 0.020	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.064	Only H-atom coordinates refined
S = 1.23	w = 1/[σ^2(Fo^2) + (0.0258P)^2 + 2.2974P] where P = (Fo^2 + 2Fc^2)/3
1582 reflections	(Δ/σ)max < 0.001
112 parameters	Δρmax = 0.49 e Å^−3
3 restraints	Δρmin = −1.07 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
Mo1	0.39809 (3)	0.107909 (16)	0.87442 (4)	0.00856 (10)
K1	0.69345 (10)	0.13694 (5)	1.35797 (11)	0.01885 (16)
O4	0.1520 (3)	0.02571 (14)	0.8247 (3)	0.0121 (4)
O5	0.1949 (3)	0.20542 (14)	0.8051 (3)	0.0128 (4)
O2	0.5000	0.0000	1.0000	0.0154 (6)
O1	0.5394 (3)	0.19638 (16)	0.9554 (4)	0.0177 (5)
O3	0.4445 (3)	0.08921 (18)	0.6296 (4)	0.0204 (5)
O6	−0.1289 (3)	0.03392 (16)	0.6788 (4)	0.0180 (5)
O7	−0.0855 (3)	0.22833 (16)	0.6731 (4)	0.0186 (5)
C3	0.0121 (4)	0.0689 (2)	0.7472 (4)	0.0127 (5)
C4	0.0355 (4)	0.1775 (2)	0.7379 (4)	0.0125 (6)
O1W	0.2887 (3)	0.11958 (15)	1.1849 (3)	0.0151 (4)
H1W	0.243 (5)	0.1777 (12)	1.228 (6)	0.023*
H2W	0.224 (5)	0.0696 (15)	1.240 (6)	0.023*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Mo1	0.00753 (14)	0.00776 (14)	0.01019 (14)	0.00028 (8)	−0.00069 (9)	0.00121 (8)
K1	0.0194 (3)	0.0179 (3)	0.0190 (3)	0.0016 (3)	−0.0002 (3)	−0.0001 (3)
O4	0.0115 (10)	0.0093 (9)	0.0152 (10)	−0.0002 (8)	−0.0004 (8)	0.0010 (8)
O5	0.0116 (10)	0.0081 (9)	0.0183 (10)	0.0005 (8)	−0.0013 (8)	0.0026 (8)
O2	0.0114 (14)	0.0122 (14)	0.0222 (16)	0.0028 (11)	−0.0011 (12)	0.0042 (12)
O1	0.0149 (11)	0.0144 (10)	0.0231 (11)	−0.0041 (8)	−0.0045 (9)	0.0028 (9)
O3	0.0186 (11)	0.0282 (12)	0.0149 (11)	−0.0001 (10)	0.0043 (9)	0.0032 (10)
O6	0.0134 (10)	0.0171 (11)	0.0225 (11)	−0.0048 (9)	−0.0048 (9)	0.0063 (9)
O7	0.0158 (11)	0.0160 (11)	0.0232 (11)	0.0042 (9)	−0.0040 (9)	0.0033 (9)
C3	0.0123 (13)	0.0131 (13)	0.0124 (13)	−0.0003 (11)	0.0002 (10)	0.0016 (11)
C4	0.0119 (13)	0.0124 (13)	0.0129 (13)	0.0016 (11)	−0.0002 (10)	−0.0003 (10)
O1W	0.0232 (12)	0.0087 (9)	0.0140 (10)	0.0008 (8)	0.0051 (9)	−0.0008 (8)

Geometric parameters (Å, º)

Mo1—O1	1.703 (2)	O4—K1^v	2.887 (2)
Mo1—O2	1.8772 (2)	O5—C4	1.302 (4)
Mo1—O3	1.692 (2)	O2—Mo1^v	1.8772 (2)
Mo1—O4	2.184 (2)	O2—K1^v	3.3036 (7)
Mo1—O5	2.083 (2)	O1—K1^vi	2.733 (2)
Mo1—O1W	2.260 (2)	O3—K1^vii	2.758 (2)
K1—O1^i	2.733 (2)	O3—K1^v	3.381 (3)
K1—O3^ii	2.758 (2)	O6—C3	1.221 (4)
K1—O6^iii	2.818 (2)	O6—K1^viii	2.818 (2)
K1—O7^iv	2.860 (2)	O7—C4	1.210 (4)
K1—O7^iii	2.864 (2)	O7—K1^ix	2.860 (2)
K1—O4^v	2.887 (2)	O7—K1^viii	2.864 (2)
K1—O1	2.930 (2)	C3—C4	1.557 (4)
K1—O1W	3.162 (3)	C3—K1^viii	3.500 (3)
K1—O2	3.3036 (7)	C4—K1^viii	3.487 (3)
K1—O3^v	3.381 (3)	O1W—H1W	0.95 (3)
O4—C3	1.285 (4)	O1W—H2W	0.95 (3)
O1—Mo1—O2	104.18 (8)	O1—K1—O2	53.52 (5)
O1—Mo1—O4	159.81 (10)	O1W—K1—O2	48.80 (4)
O1—Mo1—O5	90.09 (10)	O1^i—K1—O3^v	133.23 (7)
O1—Mo1—O1W	85.48 (10)	O3^ii—K1—O3^v	61.85 (8)
O2—Mo1—O4	86.44 (5)	O6^iii—K1—O3^v	67.34 (6)
O2—Mo1—O5	155.00 (6)	O7^iv—K1—O3^v	146.59 (7)
O2—Mo1—O1W	79.95 (6)	O7^iii—K1—O3^v	125.10 (6)
O3—Mo1—O1	104.30 (12)	O4^v—K1—O3^v	51.68 (6)
O3—Mo1—O2	100.62 (9)	O1—K1—O3^v	101.32 (6)
O3—Mo1—O4	90.22 (10)	O1W—K1—O3^v	69.45 (6)
O3—Mo1—O5	95.45 (10)	O2—K1—O3^v	48.56 (4)
O3—Mo1—O1W	169.61 (10)	C3—O4—Mo1	117.08 (18)
O4—Mo1—O1W	79.45 (8)	C3—O4—K1^v	123.87 (18)
O5—Mo1—O4	74.39 (8)	Mo1—O4—K1^v	97.60 (7)
O5—Mo1—O1W	80.86 (8)	C4—O5—Mo1	120.38 (18)
O1^i—K1—O3^ii	75.24 (8)	Mo1^v—O2—Mo1	180.0
O1^i—K1—O6^iii	117.34 (7)	Mo1^v—O2—K1	91.559 (14)
O3^ii—K1—O6^iii	71.99 (7)	Mo1—O2—K1	88.441 (14)
O1^i—K1—O7^iv	77.61 (7)	Mo1^v—O2—K1^v	88.441 (14)
O3^ii—K1—O7^iv	151.54 (8)	Mo1—O2—K1^v	91.559 (14)
O6^iii—K1—O7^iv	114.29 (7)	K1—O2—K1^v	180.0
O1^i—K1—O7^iii	70.57 (7)	Mo1—O1—K1^vi	146.15 (12)
O3^ii—K1—O7^iii	91.41 (7)	Mo1—O1—K1	105.19 (10)
O6^iii—K1—O7^iii	58.70 (7)	K1^vi—O1—K1	108.52 (8)
O7^iv—K1—O7^iii	71.49 (4)	Mo1—O3—K1^vii	140.61 (13)
O1^i—K1—O4^v	168.94 (7)	Mo1—O3—K1^v	92.40 (9)
O3^ii—K1—O4^v	112.47 (7)	K1^vii—O3—K1^v	118.15 (8)
O6^iii—K1—O4^v	73.35 (7)	C3—O6—K1^viii	114.18 (19)
O7^iv—K1—O4^v	95.64 (7)	C4—O7—K1^ix	133.7 (2)
O7^iii—K1—O4^v	115.92 (6)	C4—O7—K1^viii	111.1 (2)
O1^i—K1—O1	79.46 (5)	K1^ix—O7—K1^viii	106.90 (8)
O3^ii—K1—O1	114.61 (7)	O6—C3—O4	127.3 (3)
O6^iii—K1—O1	163.20 (7)	O6—C3—C4	119.1 (3)
O7^iv—K1—O1	67.90 (6)	O4—C3—C4	113.5 (2)
O7^iii—K1—O1	133.54 (7)	O6—C3—K1^viii	47.26 (15)
O4^v—K1—O1	89.91 (6)	O4—C3—K1^viii	155.7 (2)
O1^i—K1—O1W	75.12 (6)	C4—C3—K1^viii	76.65 (15)
O3^ii—K1—O1W	62.59 (7)	O7—C4—O5	125.4 (3)
O6^iii—K1—O1W	127.85 (6)	O7—C4—C3	121.6 (3)
O7^iv—K1—O1W	117.86 (6)	O5—C4—C3	113.1 (2)
O7^iii—K1—O1W	141.34 (7)	O7—C4—K1^viii	50.04 (16)
O4^v—K1—O1W	100.94 (6)	O5—C4—K1^viii	153.9 (2)
O1—K1—O1W	52.88 (6)	C3—C4—K1^viii	77.60 (15)
O1^i—K1—O2	120.57 (5)	Mo1—O1W—K1	85.96 (7)
O3^ii—K1—O2	92.01 (6)	Mo1—O1W—H1W	120 (2)
O6^iii—K1—O2	112.53 (5)	K1—O1W—H1W	101 (2)
O7^iv—K1—O2	109.19 (5)	Mo1—O1W—H2W	121 (2)
O7^iii—K1—O2	168.85 (5)	K1—O1W—H2W	115 (2)
O4^v—K1—O2	53.06 (4)	H1W—O1W—H2W	109.4 (15)
O3—Mo1—O4—C3	−84.5 (2)	O3^v—K1—O1—Mo1	10.53 (12)
O1—Mo1—O4—C3	52.0 (4)	C4^iii—K1—O1—Mo1	164.73 (10)
O2—Mo1—O4—C3	174.9 (2)	C3^iii—K1—O1—Mo1	117.2 (2)
O5—Mo1—O4—C3	11.1 (2)	O1^i—K1—O1—K1^vi	61.34 (12)
O1W—Mo1—O4—C3	94.4 (2)	O3^ii—K1—O1—K1^vi	129.61 (9)
K1—Mo1—O4—C3	126.00 (19)	O6^iii—K1—O1—K1^vi	−120.5 (2)
K1^v—Mo1—O4—C3	−134.4 (2)	O7^iv—K1—O1—K1^vi	−19.45 (8)
O3—Mo1—O4—K1^v	49.89 (10)	O7^iii—K1—O1—K1^vi	11.40 (14)
O1—Mo1—O4—K1^v	−173.6 (2)	O4^v—K1—O1—K1^vi	−115.58 (8)
O2—Mo1—O4—K1^v	−50.74 (5)	O1W—K1—O1—K1^vi	140.58 (11)
O5—Mo1—O4—K1^v	145.48 (9)	O2—K1—O1—K1^vi	−157.30 (10)
O1W—Mo1—O4—K1^v	−131.16 (8)	O3^v—K1—O1—K1^vi	−166.33 (7)
K1—Mo1—O4—K1^v	−99.59 (6)	C4^iii—K1—O1—K1^vi	−12.13 (17)
O3—Mo1—O5—C4	78.5 (2)	C3^iii—K1—O1—K1^vi	−59.7 (2)
O1—Mo1—O5—C4	−177.1 (2)	O1—Mo1—O3—K1^vii	11.1 (2)
O2—Mo1—O5—C4	−51.5 (3)	O2—Mo1—O3—K1^vii	−96.63 (19)
O4—Mo1—O5—C4	−10.2 (2)	O5—Mo1—O3—K1^vii	102.61 (19)
O1W—Mo1—O5—C4	−91.7 (2)	O4—Mo1—O3—K1^vii	176.95 (19)
K1—Mo1—O5—C4	−135.9 (2)	O1W—Mo1—O3—K1^vii	171.2 (4)
K1^v—Mo1—O5—C4	17.4 (2)	K1—Mo1—O3—K1^vii	−35.6 (3)
O3—Mo1—O2—K1	132.59 (9)	K1^v—Mo1—O3—K1^vii	−142.7 (2)
O1—Mo1—O2—K1	24.74 (9)	O1—Mo1—O3—K1^v	153.79 (8)
O5—Mo1—O2—K1	−98.33 (14)	O2—Mo1—O3—K1^v	46.03 (6)
O4—Mo1—O2—K1	−137.86 (6)	O5—Mo1—O3—K1^v	−114.73 (7)
O1W—Mo1—O2—K1	−57.95 (6)	O4—Mo1—O3—K1^v	−40.39 (7)
O3—Mo1—O2—K1^v	−47.41 (9)	O1W—Mo1—O3—K1^v	−46.1 (6)
O1—Mo1—O2—K1^v	−155.26 (9)	K1—Mo1—O3—K1^v	107.08 (8)
O5—Mo1—O2—K1^v	81.67 (14)	K1^viii—O6—C3—O4	−148.9 (3)
O4—Mo1—O2—K1^v	42.14 (6)	K1^viii—O6—C3—C4	29.1 (3)
O1W—Mo1—O2—K1^v	122.05 (6)	Mo1—O4—C3—O6	167.8 (3)
O6^iii—K1—O2—Mo1^v	−6.24 (6)	K1^v—O4—C3—O6	46.3 (4)
O7^iv—K1—O2—Mo1^v	121.78 (5)	Mo1—O4—C3—C4	−10.3 (3)
O7^iii—K1—O2—Mo1^v	30.2 (3)	K1^v—O4—C3—C4	−131.8 (2)
O4^v—K1—O2—Mo1^v	39.33 (5)	Mo1—O4—C3—K1^viii	100.4 (5)
O1W—K1—O2—Mo1^v	−127.55 (5)	K1^v—O4—C3—K1^viii	−21.0 (6)
O3^v—K1—O2—Mo1^v	−28.90 (6)	K1^ix—O7—C4—O5	−69.6 (4)
C4^iii—K1—O2—Mo1^v	24.25 (11)	K1^viii—O7—C4—O5	147.3 (3)
C3^iii—K1—O2—Mo1^v	7.83 (7)	K1^ix—O7—C4—C3	110.6 (3)
O1^i—K1—O2—Mo1	28.44 (6)	K1^viii—O7—C4—C3	−32.5 (3)
O3^ii—K1—O2—Mo1	102.45 (5)	K1^ix—O7—C4—K1^viii	143.1 (3)
O6^iii—K1—O2—Mo1	173.76 (6)	Mo1—O5—C4—O7	−171.7 (2)
O7^iv—K1—O2—Mo1	−58.22 (5)	Mo1—O5—C4—C3	8.2 (3)
O7^iii—K1—O2—Mo1	−149.8 (3)	Mo1—O5—C4—K1^viii	−101.6 (4)
O4^v—K1—O2—Mo1	−140.67 (5)	O6—C3—C4—O7	3.4 (4)
O1—K1—O2—Mo1	−17.05 (6)	O4—C3—C4—O7	−178.3 (3)
O1W—K1—O2—Mo1	52.45 (5)	K1^viii—C3—C4—O7	24.9 (3)
C4^iii—K1—O2—Mo1	−155.75 (11)	O6—C3—C4—O5	−176.4 (3)
C3^iii—K1—O2—Mo1	−172.17 (7)	O4—C3—C4—O5	1.8 (4)
O3—Mo1—O1—K1^vi	40.3 (2)	K1^viii—C3—C4—O5	−154.9 (2)
O2—Mo1—O1—K1^vi	145.41 (19)	O6—C3—C4—K1^viii	−21.5 (3)
O5—Mo1—O1—K1^vi	−55.3 (2)	O4—C3—C4—K1^viii	156.7 (2)
O4—Mo1—O1—K1^vi	−94.5 (3)	O3—Mo1—O1W—K1	156.6 (5)
O1W—Mo1—O1—K1^vi	−136.2 (2)	O1—Mo1—O1W—K1	−42.73 (8)
K1—Mo1—O1—K1^vi	174.7 (3)	O2—Mo1—O1W—K1	62.55 (3)
K1^v—Mo1—O1—K1^vi	95.7 (2)	O5—Mo1—O1W—K1	−133.55 (7)
O3—Mo1—O1—K1	−134.35 (11)	O4—Mo1—O1W—K1	150.77 (7)
O2—Mo1—O1—K1	−29.25 (9)	K1^v—Mo1—O1W—K1	113.85 (4)
O5—Mo1—O1—K1	130.01 (9)	O1^i—K1—O1W—Mo1	117.46 (8)
O4—Mo1—O1—K1	90.8 (3)	O3^ii—K1—O1W—Mo1	−161.71 (9)
O1W—Mo1—O1—K1	49.18 (9)	O6^iii—K1—O1W—Mo1	−129.27 (8)
K1^v—Mo1—O1—K1	−78.94 (18)	O7^iv—K1—O1W—Mo1	50.51 (9)
O1^i—K1—O1—Mo1	−121.79 (6)	O7^iii—K1—O1W—Mo1	145.43 (9)
O3^ii—K1—O1—Mo1	−53.53 (13)	O4^v—K1—O1W—Mo1	−51.94 (7)
O6^iii—K1—O1—Mo1	56.4 (3)	O1—K1—O1W—Mo1	29.53 (7)
O7^iv—K1—O1—Mo1	157.42 (13)	O2—K1—O1W—Mo1	−41.29 (4)
O7^iii—K1—O1—Mo1	−171.74 (9)	O3^v—K1—O1W—Mo1	−93.61 (7)
O4^v—K1—O1—Mo1	61.29 (11)	C4^iii—K1—O1W—Mo1	171.80 (13)
O1W—K1—O1—Mo1	−42.56 (9)	C3^iii—K1—O1W—Mo1	−138.50 (11)
O2—K1—O1—Mo1	19.56 (7)

Symmetry codes: (i) x, −y+1/2, z+1/2; (ii) x, y, z+1; (iii) x+1, y, z+1; (iv) x+1, −y+1/2, z+1/2; (v) −x+1, −y, −z+2; (vi) x, −y+1/2, z−1/2; (vii) x, y, z−1; (viii) x−1, y, z−1; (ix) x−1, −y+1/2, z−1/2.

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
O1W—H1W···O5^i	0.95 (3)	1.78 (1)	2.720 (3)	170 (3)
O1W—H2W···O6^x	0.95 (3)	1.73 (3)	2.676 (3)	170 (3)

Symmetry codes: (i) x, −y+1/2, z+1/2; (x) −x, −y, −z+2.