cyclo-Tetra-μ-oxido-tetra-kis-[(acetyl-acetonato-κO,O')bis-(ethano-lato-κO)niobium(V)].

The asymmetric unit of the title tetra-nuclear niobium(V) compound, [Nb(4)(C(2)H(5)O)(8)(C(5)H(7)O(2))(4)O(4)], contains two Nb(V) atoms, two bridging O atoms, two acetyl-acetonate and four ethano-late ligands. Each Nb(V) atom is six-coordinated by the bridging O atoms, two ethano-late and one chelating acetyl-acetonate ligands. The Nb-O distances vary between 1.817 (2) and 2.201 (2) Å and the O-Nb-O angles vary between 78.88 (8) and 102.78 (9)°, illustrating the significant distortion from ideal ocahedral geometry. The rest of the tetra-nuclear unit is generated through an inversion centre. The C atoms of two of the ethano-late mol-ecules are disordered over two sites [occupancy ratio 0.601 (12):0.399 (12)].

Related literature

For similar structures, see: Ooi & Sotofte (2004 ▶); Cotton et al. (1985 ▶, 1987 ▶); Steunou et al. (1998 ▶). For applications of acetyl­acetone in industry, see: Steyn et al. (1992 ▶, 1997 ▶, 2008 ▶); Otto et al. (1998 ▶); Roodt & Steyn (2000 ▶); Brink et al. (2010 ▶); Viljoen et al. (2008 ▶, 2009 ▶, 2010 ▶); Herbst et al. (2010 ▶). For a review article about structure–reactivity relationships, see: Roodt et al. (2011 ▶)

Experimental

Crystal data

[Nb4(C2H5O)8(C5H7O2)4O4]

M = 1192.54

Monoclinic,

a = 13.907 (5) Å

b = 12.662 (5) Å

c = 21.354 (5) Å

β = 136.982 (13)°

V = 2565.4 (15) Å3

Z = 2

Mo Kα radiation

μ = 0.94 mm−1

T = 180 K

0.48 × 0.32 × 0.27 mm

Data collection

Bruker X8 APEXII 4K Kappa CCD diffractometer

Absorption correction: multi-scan (SADABS; Bruker, 2004 ▶) T min = 0.701, T max = 0.778

42149 measured reflections

6191 independent reflections

5355 reflections with I > 2σ(I)

R int = 0.032

Refinement

R[F 2 > 2σ(F 2)] = 0.031

wR(F 2) = 0.080

S = 1.06

6191 reflections

310 parameters

85 restraints

H-atom parameters constrained

Δρmax = 2.43 e Å−3

Δρmin = −1.32 e Å−3

Data collection: APEX2 (Bruker, 2010 ▶); cell refinement: SAINT-Plus (Bruker, 2004 ▶); data reduction: SAINT-Plus; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: DIAMOND (Brandenburg & Putz, 2005 ▶); software used to prepare material for publication: WinGX (Farrugia, 1999 ▶).

Crystal structure: contains datablock(s) global, I. DOI: 10.1107/S1600536811044138/bg2426sup1.cif

Structure factors: contains datablock(s) I. DOI: 10.1107/S1600536811044138/bg2426Isup2.hkl

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

[Nb4(C2H5O)8(C5H7O2)4O4]	F(000) = 1216
Mr = 1192.54	Dx = 1.544 Mg m−3
Monoclinic, P21/c	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ybc	Cell parameters from 9935 reflections
a = 13.907 (5) Å	θ = 2.7–28.3°
b = 12.662 (5) Å	µ = 0.94 mm−1
c = 21.354 (5) Å	T = 180 K
β = 136.982 (13)°	Cuboid, colourless
V = 2565.4 (15) Å3	0.48 × 0.32 × 0.27 mm
Z = 2

Bruker X8 APEXII 4K Kappa CCD diffractometer	6191 independent reflections
Radiation source: fine-focus sealed tube	5355 reflections with I > 2σ(I)
graphite	Rint = 0.032
φ and ω scans	θmax = 28°, θmin = 3.2°
Absorption correction: multi-scan (SADABS; Bruker, 2004)	h = −18→18
Tmin = 0.701, Tmax = 0.778	k = −16→16
42149 measured reflections	l = −25→28

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) = 0.080	H-atom parameters constrained
S = 1.06	w = 1/[σ2(Fo2) + (0.031P)2 + 4.1146P] where P = (Fo2 + 2Fc2)/3
6191 reflections	(Δ/σ)max = 0.002
310 parameters	Δρmax = 2.43 e Å−3
85 restraints	Δρmin = −1.32 e Å−3

Experimental. The intensity data were collected on a Bruker X8 ApexII 4 K Kappa CCD diffractometer using an exposure time of 40 s/frame. A total of 1709 frames were collected with a frame width of 0.5° covering up to θ = 28.39° with 99.9% completeness accomplished.

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 > 2σ(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	Occ. (<1)
C1	0.4871 (3)	0.5567 (3)	0.2203 (2)	0.0376 (6)
C2	0.5266 (3)	0.6468 (3)	0.2724 (2)	0.0440 (7)
H2	0.4807	0.7098	0.2414	0.053*
C3	0.6286 (3)	0.6484 (2)	0.3664 (2)	0.0377 (6)
C4	0.3652 (4)	0.5634 (3)	0.1170 (2)	0.0635 (11)
H4A	0.3966	0.544	0.0908	0.095*
H4B	0.3295	0.6344	0.0993	0.095*
H4C	0.2918	0.5161	0.0952	0.095*
C5	0.6564 (5)	0.7475 (3)	0.4162 (3)	0.0597 (10)
H5A	0.6275	0.7376	0.445	0.09*
H5B	0.6043	0.8049	0.3732	0.09*
H5C	0.7553	0.7635	0.462	0.09*
C6	0.4762 (4)	0.3502 (4)	0.3446 (3)	0.0611 (10)
H6A	0.4608	0.283	0.3581	0.073*
H6B	0.4148	0.3529	0.2791	0.073*
C7	0.4382 (5)	0.4360 (5)	0.3696 (4)	0.0893 (17)
H7A	0.3415	0.4284	0.336	0.134*
H7B	0.4506	0.5027	0.3548	0.134*
H7C	0.4976	0.4331	0.4342	0.134*
C8	0.7632 (4)	0.2881 (3)	0.2822 (3)	0.0485 (8)
H8A	0.8199	0.3423	0.2892	0.058*
H8B	0.6702	0.2895	0.2191	0.058*
C10	1.0999 (3)	0.4854 (3)	0.3539 (2)	0.0402 (7)
C11	1.1829 (4)	0.5716 (3)	0.3770 (3)	0.0494 (8)
H11	1.2651	0.5589	0.3937	0.059*
C12	1.1506 (4)	0.6763 (3)	0.3769 (2)	0.0468 (8)
C13	1.1348 (4)	0.3772 (3)	0.3489 (3)	0.0571 (9)
H13A	1.0784	0.36	0.2861	0.086*
H13B	1.116	0.3276	0.3729	0.086*
H13C	1.2328	0.3739	0.3844	0.086*
C14	1.2474 (5)	0.7644 (4)	0.4018 (3)	0.0672 (12)
H14A	1.3141	0.7374	0.4039	0.101*
H14B	1.2967	0.7925	0.4609	0.101*
H14C	1.1926	0.8194	0.3566	0.101*
C15	0.9542 (5)	0.8296 (3)	0.4372 (3)	0.0672 (11)
H15A	1.0526	0.81	0.4879	0.081*
H15B	0.921	0.8503	0.4625	0.081*
C16	0.9434 (7)	0.9182 (4)	0.3908 (4)	0.103 (2)
H16A	0.8466	0.9396	0.3416	0.155*
H16B	0.9777	0.8989	0.3665	0.155*
H16C	0.9986	0.9755	0.4333	0.155*
O1	0.81776 (19)	0.51714 (15)	0.36184 (13)	0.0296 (4)
O2	0.54526 (19)	0.46715 (16)	0.25306 (13)	0.0342 (4)
O3	0.7048 (2)	0.56870 (15)	0.41852 (13)	0.0323 (4)
O4	0.6178 (2)	0.35591 (17)	0.39197 (14)	0.0351 (4)
O5	0.90700 (18)	0.40537 (14)	0.51497 (12)	0.0290 (4)
O6	0.7517 (2)	0.31023 (15)	0.34129 (13)	0.0322 (4)
O7	0.9881 (2)	0.49253 (17)	0.33447 (14)	0.0362 (4)
O8	1.0433 (2)	0.70416 (18)	0.35616 (16)	0.0434 (5)
O9	0.8765 (2)	0.74043 (15)	0.38001 (14)	0.0386 (5)
O10	0.7637 (2)	0.62579 (19)	0.22326 (14)	0.0458 (5)
Nb1	0.74205 (2)	0.422519 (18)	0.394088 (15)	0.02353 (7)
Nb2	0.90559 (2)	0.611158 (19)	0.352545 (16)	0.02815 (7)
C17A	0.7186 (18)	0.6351 (11)	0.1421 (9)	0.075 (4)	0.399 (12)
H17A	0.7289	0.7091	0.1364	0.09*	0.399 (12)
H17B	0.618	0.6213	0.0954	0.09*	0.399 (12)
C18A	0.7686 (18)	0.5806 (10)	0.1159 (9)	0.088 (5)	0.399 (12)
H18A	0.6919	0.5624	0.0521	0.132*	0.399 (12)
H18B	0.8142	0.5173	0.1519	0.132*	0.399 (12)
H18C	0.8352	0.6235	0.1253	0.132*	0.399 (12)
C17B	0.7207 (17)	0.5822 (11)	0.1469 (7)	0.145 (7)	0.601 (12)
H17C	0.7969	0.5989	0.1545	0.174*	0.601 (12)
H17D	0.7274	0.5067	0.1572	0.174*	0.601 (12)
C18B	0.6150 (15)	0.5917 (14)	0.0646 (7)	0.184 (8)	0.601 (12)
H18D	0.5957	0.6654	0.049	0.276*	0.601 (12)
H18E	0.5366	0.5595	0.0484	0.276*	0.601 (12)
H18F	0.6292	0.5578	0.0317	0.276*	0.601 (12)
C9A	0.828 (3)	0.1850 (12)	0.3022 (14)	0.068 (4)	0.53 (5)
H9A1	0.9206	0.1841	0.3642	0.102*	0.53 (5)
H9A2	0.8335	0.1718	0.2608	0.102*	0.53 (5)
H9A3	0.7713	0.1312	0.2948	0.102*	0.53 (5)
C9B	0.885 (4)	0.218 (3)	0.330 (2)	0.076 (7)	0.47 (5)
H9B1	0.9691	0.2514	0.3856	0.114*	0.47 (5)
H9B2	0.8959	0.2052	0.2909	0.114*	0.47 (5)
H9B3	0.8706	0.1524	0.3442	0.114*	0.47 (5)

	U11	U22	U33	U12	U13	U23
C1	0.0264 (13)	0.0447 (17)	0.0305 (14)	0.0065 (12)	0.0172 (12)	0.0082 (12)
C2	0.0424 (17)	0.0394 (16)	0.0411 (17)	0.0187 (13)	0.0276 (15)	0.0129 (13)
C3	0.0385 (15)	0.0342 (15)	0.0430 (17)	0.0098 (12)	0.0306 (14)	0.0032 (12)
C4	0.050 (2)	0.067 (3)	0.0319 (17)	0.0135 (19)	0.0168 (17)	0.0112 (16)
C5	0.073 (3)	0.0414 (19)	0.055 (2)	0.0217 (18)	0.044 (2)	0.0049 (16)
C6	0.0350 (17)	0.085 (3)	0.065 (2)	−0.0114 (18)	0.0373 (19)	−0.001 (2)
C7	0.051 (2)	0.138 (5)	0.096 (4)	0.005 (3)	0.059 (3)	−0.010 (3)
C8	0.061 (2)	0.0451 (18)	0.053 (2)	−0.0026 (15)	0.0460 (19)	−0.0075 (15)
C10	0.0412 (16)	0.0536 (19)	0.0353 (15)	−0.0021 (14)	0.0310 (14)	−0.0027 (13)
C11	0.0457 (18)	0.065 (2)	0.053 (2)	−0.0088 (16)	0.0408 (18)	−0.0069 (17)
C12	0.0495 (19)	0.058 (2)	0.0404 (17)	−0.0157 (16)	0.0354 (16)	−0.0031 (15)
C13	0.063 (2)	0.058 (2)	0.069 (3)	0.0047 (18)	0.054 (2)	−0.0039 (19)
C14	0.072 (3)	0.077 (3)	0.068 (3)	−0.037 (2)	0.056 (2)	−0.017 (2)
C15	0.069 (3)	0.043 (2)	0.061 (2)	−0.0029 (18)	0.038 (2)	−0.0100 (18)
C16	0.124 (5)	0.041 (2)	0.084 (4)	−0.015 (3)	0.057 (4)	−0.007 (2)
O1	0.0278 (9)	0.0305 (9)	0.0309 (10)	−0.0011 (7)	0.0216 (8)	0.0001 (8)
O2	0.0233 (9)	0.0367 (11)	0.0271 (9)	0.0011 (8)	0.0134 (8)	0.0016 (8)
O3	0.0328 (10)	0.0305 (10)	0.0325 (10)	0.0072 (8)	0.0235 (9)	0.0019 (8)
O4	0.0279 (9)	0.0416 (11)	0.0370 (11)	−0.0051 (8)	0.0241 (9)	−0.0019 (9)
O5	0.0244 (9)	0.0302 (9)	0.0264 (9)	−0.0001 (7)	0.0167 (8)	0.0008 (7)
O6	0.0343 (10)	0.0286 (10)	0.0345 (10)	−0.0007 (8)	0.0254 (9)	−0.0033 (8)
O7	0.0365 (10)	0.0408 (11)	0.0386 (11)	−0.0071 (9)	0.0298 (10)	−0.0068 (9)
O8	0.0483 (13)	0.0421 (12)	0.0479 (13)	−0.0052 (10)	0.0378 (12)	0.0059 (10)
O9	0.0347 (10)	0.0269 (10)	0.0412 (11)	0.0046 (8)	0.0236 (10)	0.0015 (8)
O10	0.0421 (12)	0.0540 (14)	0.0261 (10)	0.0004 (10)	0.0201 (10)	0.0054 (9)
Nb1	0.01917 (11)	0.02425 (12)	0.02382 (12)	0.00004 (8)	0.01465 (10)	−0.00014 (8)
Nb2	0.02496 (12)	0.03010 (13)	0.02436 (12)	−0.00099 (9)	0.01643 (11)	0.00325 (9)
C17A	0.111 (9)	0.059 (8)	0.047 (6)	0.011 (7)	0.056 (6)	0.018 (6)
C18A	0.149 (14)	0.080 (9)	0.066 (8)	−0.016 (8)	0.088 (10)	−0.010 (6)
C17B	0.209 (12)	0.087 (8)	0.041 (4)	0.084 (8)	0.060 (6)	0.026 (5)
C18B	0.122 (11)	0.31 (2)	0.062 (5)	0.006 (11)	0.048 (6)	−0.063 (9)
C9A	0.113 (12)	0.048 (6)	0.084 (8)	0.008 (6)	0.085 (9)	−0.009 (5)
C9B	0.107 (14)	0.075 (13)	0.098 (13)	0.051 (10)	0.091 (12)	0.045 (9)

C1—O2	1.266 (4)	C15—C16	1.429 (6)
C1—C2	1.396 (5)	C15—H15A	0.97
C1—C4	1.509 (4)	C15—H15B	0.97
C2—C3	1.370 (4)	C16—H16A	0.96
C2—H2	0.93	C16—H16B	0.96
C3—O3	1.286 (3)	C16—H16C	0.96
C3—C5	1.501 (4)	O1—Nb2	1.8173 (19)
C4—H4A	0.96	O1—Nb1	2.0196 (19)
C4—H4B	0.96	O2—Nb1	2.197 (2)
C4—H4C	0.96	O3—Nb1	2.089 (2)
C5—H5A	0.96	O4—Nb1	1.894 (2)
C5—H5B	0.96	O5—Nb1	1.8204 (19)
C5—H5C	0.96	O5—Nb2i	2.0145 (19)
C6—O4	1.412 (4)	O6—Nb1	1.8793 (19)
C6—C7	1.468 (6)	O7—Nb2	2.090 (2)
C6—H6A	0.97	O8—Nb2	2.201 (2)
C6—H6B	0.97	O9—Nb2	1.880 (2)
C7—H7A	0.96	O10—C17A	1.349 (12)
C7—H7B	0.96	O10—C17B	1.377 (11)
C7—H7C	0.96	O10—Nb2	1.893 (2)
C8—O6	1.411 (4)	Nb2—O5i	2.0145 (19)
C8—C9A	1.460 (15)	C17A—C18A	1.357 (15)
C8—C9B	1.476 (16)	C17A—H17A	0.97
C8—H8A	0.97	C17A—H17B	0.97
C8—H8B	0.97	C18A—H18A	0.96
C10—O7	1.287 (4)	C18A—H18B	0.96
C10—C11	1.390 (5)	C18A—H18C	0.96
C10—C13	1.484 (5)	C17B—C18B	1.219 (12)
C11—C12	1.398 (5)	C17B—H17C	0.97
C11—H11	0.93	C17B—H17D	0.97
C12—O8	1.258 (4)	C18B—H18D	0.96
C12—C14	1.514 (5)	C18B—H18E	0.96
C13—H13A	0.96	C18B—H18F	0.96
C13—H13B	0.96	C9A—H9A1	0.96
C13—H13C	0.96	C9A—H9A2	0.96
C14—H14A	0.96	C9A—H9A3	0.96
C14—H14B	0.96	C9B—H9B1	0.96
C14—H14C	0.96	C9B—H9B2	0.96
C15—O9	1.415 (4)	C9B—H9B3	0.96
O2—C1—C2	124.8 (3)	C15—C16—H16B	109.5
O2—C1—C4	116.1 (3)	H16A—C16—H16B	109.5
C2—C1—C4	119.1 (3)	C15—C16—H16C	109.5
C3—C2—C1	124.3 (3)	H16A—C16—H16C	109.5
C3—C2—H2	117.9	H16B—C16—H16C	109.5
C1—C2—H2	117.9	Nb2—O1—Nb1	170.20 (11)
O3—C3—C2	124.9 (3)	C1—O2—Nb1	129.84 (19)
O3—C3—C5	114.9 (3)	C3—O3—Nb1	132.58 (19)
C2—C3—C5	120.3 (3)	C6—O4—Nb1	144.2 (2)
C1—C4—H4A	109.5	Nb1—O5—Nb2i	177.29 (11)
C1—C4—H4B	109.5	C8—O6—Nb1	142.3 (2)
H4A—C4—H4B	109.5	C10—O7—Nb2	133.4 (2)
C1—C4—H4C	109.5	C12—O8—Nb2	129.8 (2)
H4A—C4—H4C	109.5	C15—O9—Nb2	139.6 (2)
H4B—C4—H4C	109.5	C17A—O10—Nb2	153.1 (7)
C3—C5—H5A	109.5	C17B—O10—Nb2	140.8 (5)
C3—C5—H5B	109.5	O5—Nb1—O6	101.06 (9)
H5A—C5—H5B	109.5	O5—Nb1—O4	99.35 (9)
C3—C5—H5C	109.5	O6—Nb1—O4	96.49 (9)
H5A—C5—H5C	109.5	O5—Nb1—O1	97.11 (8)
H5B—C5—H5C	109.5	O6—Nb1—O1	87.74 (8)
O4—C6—C7	112.7 (3)	O4—Nb1—O1	161.86 (8)
O4—C6—H6A	109.1	O5—Nb1—O3	92.12 (8)
C7—C6—H6A	109.1	O6—Nb1—O3	163.72 (8)
O4—C6—H6B	109.1	O4—Nb1—O3	90.68 (9)
C7—C6—H6B	109.1	O1—Nb1—O3	81.13 (8)
H6A—C6—H6B	107.8	O5—Nb1—O2	171.80 (8)
C6—C7—H7A	109.5	O6—Nb1—O2	86.33 (8)
C6—C7—H7B	109.5	O4—Nb1—O2	83.19 (9)
H7A—C7—H7B	109.5	O1—Nb1—O2	79.48 (8)
C6—C7—H7C	109.5	O3—Nb1—O2	80.01 (8)
H7A—C7—H7C	109.5	O1—Nb2—O9	102.78 (9)
H7B—C7—H7C	109.5	O1—Nb2—O10	98.99 (10)
O6—C8—C9A	111.3 (7)	O9—Nb2—O10	97.89 (10)
O6—C8—C9B	109.2 (9)	O1—Nb2—O5i	93.52 (8)
O6—C8—H8A	109.4	O9—Nb2—O5i	90.28 (8)
C9A—C8—H8A	109.4	O10—Nb2—O5i	163.13 (9)
C9B—C8—H8A	85.6	O1—Nb2—O7	93.03 (8)
O6—C8—H8B	109.4	O9—Nb2—O7	162.89 (9)
C9A—C8—H8B	109.4	O10—Nb2—O7	85.90 (10)
C9B—C8—H8B	131.4	O5i—Nb2—O7	82.15 (8)
H8A—C8—H8B	108	O1—Nb2—O8	169.64 (8)
O7—C10—C11	123.6 (3)	O9—Nb2—O8	84.44 (9)
O7—C10—C13	115.1 (3)	O10—Nb2—O8	87.20 (10)
C11—C10—C13	121.4 (3)	O5i—Nb2—O8	78.88 (8)
C10—C11—C12	124.2 (3)	O7—Nb2—O8	79.06 (9)
C10—C11—H11	117.9	O10—C17A—C18A	126.0 (13)
C12—C11—H11	117.9	O10—C17A—H17A	105.8
O8—C12—C11	124.2 (3)	C18A—C17A—H17A	105.8
O8—C12—C14	115.9 (4)	O10—C17A—H17B	105.8
C11—C12—C14	119.8 (3)	C18A—C17A—H17B	105.8
C10—C13—H13A	109.5	H17A—C17A—H17B	106.2
C10—C13—H13B	109.5	C18B—C17B—O10	133.5 (13)
H13A—C13—H13B	109.5	C18B—C17B—H17C	103.8
C10—C13—H13C	109.5	O10—C17B—H17C	103.8
H13A—C13—H13C	109.5	C18B—C17B—H17D	103.8
H13B—C13—H13C	109.5	O10—C17B—H17D	103.8
C12—C14—H14A	109.5	H17C—C17B—H17D	105.4
C12—C14—H14B	109.5	C17B—C18B—H18D	109.5
H14A—C14—H14B	109.5	C17B—C18B—H18E	109.5
C12—C14—H14C	109.5	H18D—C18B—H18E	109.5
H14A—C14—H14C	109.5	C17B—C18B—H18F	109.5
H14B—C14—H14C	109.5	H18D—C18B—H18F	109.5
O9—C15—C16	113.7 (4)	H18E—C18B—H18F	109.5
O9—C15—H15A	108.8	C8—C9A—H9A1	109.5
C16—C15—H15A	108.8	C8—C9A—H9A2	109.5
O9—C15—H15B	108.8	C8—C9A—H9A3	109.5
C16—C15—H15B	108.8	C8—C9B—H9B1	109.5
H15A—C15—H15B	107.7	C8—C9B—H9B2	109.5
C15—C16—H16A	109.5	C8—C9B—H9B3	109.5