Redetermination of bis­(acetyl­acetonato)­oxidopyridine­vanadium(IV)

The crystal structure of the title compound, [VO(C₅H₇O₂)₂(C₅H₅N)], has been reported previously [Meicheng, Lifeng & Youqi (1984). Kexue Tongbao, 29, 759-764], with an R value of 0.13. The current redetermination shows a significant improvement in the precision of the geometric parameters. The V atom binds five O atoms and one N atom from the pyridine ligand in a distorted octa­hedral configuration; the acetyl­acetonate anions act as bidentate ligands. A crystallographic twofold axis passes through the V, vanadyl O, and pyridine N and para-C atoms.

Key indicators

• Single-crystal X-ray study
• T = 296 K
• Mean [sigma](C-C) = 0.003 Å
• R factor = 0.039
• wR factor = 0.116
• Data-to-parameter ratio = 25.0

checkCIF/PLATON results

No syntax errors found



Alert level B
PLAT430_ALERT_2_B Short Inter D...A Contact  O2     ..  N1      ..       2.86 Ang.

Alert level C
PLAT042_ALERT_1_C Calc. and Rep. MoietyFormula Strings Differ ....          ?
PLAT062_ALERT_4_C Rescale T(min) & T(max) by .....................       0.86
PLAT764_ALERT_4_C Overcomplete CIF Bond List Detected (Rep/Expd) .       1.13 Ratio

Alert level G
ABSTM02_ALERT_3_G  When printed, the submitted absorption T values will be
            replaced by the scaled T values. Since the ratio of scaled T's
            is identical to the ratio of reported T values, the scaling
            does not imply a change to the absorption corrections used in
            the study.
            Ratio of Tmax expected/reported      0.860
            Tmax scaled      0.860 Tmin scaled      0.776
PLAT794_ALERT_5_G Check Predicted Bond Valency for V1          (4)       4.14

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

   1 ALERT type 1 CIF construction/syntax error, inconsistent or missing data
   1 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
   2 ALERT type 4 Improvement, methodology, query or suggestion
   1 ALERT type 5 Informative message, check

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S1. Comment

The crystal structure of the title compound, VO(C₅H₇O)₂C₅H₅N, was determined previously by (Meicheng et al., 1984). The original structure refinement converged with R1 = 0.13 [CUCWUS; Cambridge Structural Database (CSD, Version 5.28, update of January 2007; Allen, 2002)]. The current redetermination shows a significant improvement in the precision of the geometric parameters. A low temperature experiment was attempted, but the crystal quickly powders under a cold nitrogen stream. One half-molecule is found in the asymmetric unit; the complete molecule is generated by a crystallographic 2 fold axis which passes through atoms O1, V1, N1 and C8. The geometry of the hexacoordinate V atom can be regarded as distorted octahedral with the two acetylacetonato ligands chelating in the equatorial plane, and the vandyl O and the pyridinal N atoms in axial positions (Fig. 1). The V1 atom is centered 0.3160 (10) Å out of the plane formed by four coordinated oxygen atoms, in the direction of the apical O1 atom. The V=O distance is 1.5976 (18) Å in good agreement with ranges observed for other VO₅N octahedral found in the Cambridge Structural Database (CSD, Version 5.28, update of January 2007; Allen, 2002)] (V=O 1.598 (11) Å for 21 observations), the cisoid angles (O–V–O and O–V–N) being 80.08 (4) – 99.92 (4)°, and transoid angles (O–V–O and O–V–N) being 160.16 (8) – 180° (Table 1). The molecules packs around a crystallographic twofold screw axis, parallel to the crystallographic b-axis (Fig. 2).

The thermal gravimetric analysis (TGA) of 1 shows a loss of one molecule of pyridine (exp. 22.03%, calc. 22.97%) at 334.98 K, followed by the loss of C₁₀H₁₆O₅(exp. 64.41%, calc. 62.23%)at 438.45 K. The residual weight for the whole process (exp. 13.56%, calc. 14.80%) is in good agreement assuming V as the final end product.

Related literature

For a related structure, see: Meicheng et al. (1984).

For related literature, see: Allen (2002).

S2. Experimental

The title compound was synthesized by refluxing VO(acac)2 (1.00 g, 3.68 mmol) dissolved pyridine (15 ml) for 2 h. After cooling to room temperature, 80 ml of diethyl ether was added. Light green single crystals of the compound were obtained by slow evaporation of the solution at room temperature over several days in a dessecator. Yield (crystals): 0.13 g (10.15%).

S3. Refinement

All H atoms on were refined using a riding model, with C—H = 0.93 Å and U_iso(H) = 1.2U_eq(C) for the methine C atoms and C—H = 0.96 Å and U_iso = 1.5U_eq(C) for the methyl C atoms.

Computing details

Data collection: APEX2, COSMO and BIS (Bruker, 2006); cell refinement: SAINT (Bruker, 2006); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: DIAMOND (Brandenburg, 2007); software used to prepare material for publication: SHELXL97.

Figures

	Fig. 1. The molecular structure with 30% probability ellipsoids. [Symmetry code: (i) 1 - x, y, 1.5 - z.]
	Fig. 2. Part of the crytal structure viewed perpendicular to the bc plane. The phenyl groups are represented as solid grey lines. Hydrogen atoms omitted for sake of clarity.

bis(acetylacetonato)oxidopyridinevanadium(IV)

Crystal data

[V(C5H7O2)2O(C5H5N)]	F(000) = 716
Mr = 344.25	Dx = 1.344 Mg m^−3
Monoclinic, C2/c	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -C 2yc	Cell parameters from 2628 reflections
a = 7.9121 (3) Å	θ = 2.9–24.1°
b = 15.5258 (7) Å	µ = 0.60 mm^−1
c = 14.2523 (6) Å	T = 296 K
β = 103.621 (3)°	Trapezoid, blue–green
V = 1701.54 (12) Å^3	0.35 × 0.35 × 0.25 mm
Z = 4

Data collection

Bruker APEX II area-detector diffractometer	1837 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.032
φ and ω scans	θmax = 30.4°, θmin = 2.9°
Absorption correction: multi-scan (SADABS; Bruker, 2006)	h = −11→11
Tmin = 0.903, Tmax = 1	k = −22→20
11650 measured reflections	l = −20→20
2595 independent reflections

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)] = 0.039	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.116	H-atom parameters constrained
S = 1.05	w = 1/[σ^2(Fo^2) + (0.0608P)^2 + 0.0762P] where P = (Fo^2 + 2Fc^2)/3
2595 reflections	(Δ/σ)max = 0.001
104 parameters	Δρmax = 0.23 e Å^−3
0 restraints	Δρmin = −0.31 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
C1	0.8337 (2)	0.61290 (12)	0.88998 (13)	0.0543 (4)
C2	0.7518 (2)	0.62217 (15)	0.96641 (14)	0.0663 (5)
H2	0.8226	0.6322	1.0275	0.08*
C3	0.5742 (2)	0.61768 (12)	0.95867 (12)	0.0525 (4)
C4	1.0287 (2)	0.61760 (18)	0.91047 (17)	0.0838 (7)
H4A	1.0753	0.5607	0.9086	0.126*
H4B	1.0731	0.6421	0.9733	0.126*
H4C	1.0623	0.6529	0.8627	0.126*
C5	0.5044 (3)	0.62994 (17)	1.04695 (13)	0.0761 (6)
H5A	0.4164	0.6738	1.0348	0.114*
H5B	0.5972	0.647	1.1001	0.114*
H5C	0.4551	0.5768	1.0624	0.114*
C6	0.6215 (2)	0.78243 (13)	0.71999 (13)	0.0592 (5)
H6	0.707	0.7525	0.6985	0.071*
C7	0.6260 (3)	0.87100 (15)	0.71941 (14)	0.0755 (6)
H7	0.7133	0.9	0.6985	0.091*
C8	0.5	0.91579 (19)	0.75	0.0835 (10)
H8	0.5	0.9757	0.75	0.1*
N1	0.5	0.73721 (13)	0.75	0.0495 (4)
O1	0.5	0.47833 (11)	0.75	0.0607 (4)
O2	0.46038 (14)	0.60333 (8)	0.88081 (8)	0.0530 (3)
O3	0.75487 (14)	0.59983 (9)	0.80249 (9)	0.0544 (3)
V1	0.5	0.58123 (3)	0.75	0.04534 (15)

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
C1	0.0421 (8)	0.0563 (10)	0.0592 (11)	0.0013 (7)	0.0014 (7)	−0.0033 (8)
C2	0.0509 (10)	0.0910 (15)	0.0500 (10)	−0.0003 (10)	−0.0018 (8)	−0.0085 (10)
C3	0.0576 (9)	0.0538 (10)	0.0444 (9)	0.0013 (8)	0.0087 (7)	0.0035 (7)
C4	0.0411 (9)	0.115 (2)	0.0879 (16)	0.0009 (11)	0.0001 (9)	−0.0218 (14)
C5	0.0798 (14)	0.1023 (18)	0.0470 (10)	−0.0041 (13)	0.0163 (9)	−0.0046 (10)
C6	0.0488 (9)	0.0674 (12)	0.0609 (11)	−0.0088 (8)	0.0119 (8)	0.0019 (9)
C7	0.0876 (15)	0.0694 (15)	0.0654 (13)	−0.0281 (12)	0.0101 (10)	0.0034 (10)
C8	0.126 (3)	0.0495 (17)	0.0649 (19)	0	0.0016 (19)	0
N1	0.0413 (9)	0.0547 (12)	0.0520 (11)	0	0.0101 (8)	0
O1	0.0631 (10)	0.0560 (11)	0.0623 (11)	0	0.0133 (8)	0
O2	0.0448 (6)	0.0710 (8)	0.0430 (6)	−0.0021 (5)	0.0095 (5)	0.0021 (5)
O3	0.0360 (6)	0.0735 (8)	0.0519 (7)	0.0035 (5)	0.0069 (5)	−0.0015 (5)
V1	0.0375 (2)	0.0560 (3)	0.0412 (2)	0	0.00648 (15)	0

Geometric parameters (Å, º)

C1—O3	1.272 (2)	C6—C7	1.376 (3)
C1—C2	1.400 (2)	C6—H6	0.93
C1—C4	1.503 (2)	C7—C8	1.368 (3)
C2—C3	1.386 (2)	C7—H7	0.93
C2—H2	0.93	C8—C7^i	1.368 (3)
C3—O2	1.273 (2)	C8—H8	0.93
C3—C5	1.500 (2)	N1—C6^i	1.339 (2)
C4—H4A	0.96	N1—V1	2.422 (2)
C4—H4B	0.96	O1—V1	1.5976 (18)
C4—H4C	0.96	O2—V1	1.9918 (11)
C5—H5A	0.96	O3—V1	1.9997 (11)
C5—H5B	0.96	V1—O2^i	1.9918 (11)
C5—H5C	0.96	V1—O3^i	1.9997 (11)
C6—N1	1.339 (2)
O3—C1—C2	124.71 (15)	C8—C7—H7	120.5
O3—C1—C4	116.22 (16)	C6—C7—H7	120.5
C2—C1—C4	119.06 (17)	C7^i—C8—C7	118.9 (3)
C3—C2—C1	125.41 (17)	C7^i—C8—H8	120.6
C3—C2—H2	117.3	C7—C8—H8	120.6
C1—C2—H2	117.3	C6—N1—C6^i	116.8 (2)
O2—C3—C2	125.04 (16)	C6—N1—V1	121.61 (11)
O2—C3—C5	115.39 (15)	C6^i—N1—V1	121.61 (11)
C2—C3—C5	119.57 (16)	C3—O2—V1	127.66 (11)
C1—C4—H4A	109.5	C1—O3—V1	127.44 (11)
C1—C4—H4B	109.5	O1—V1—O2	99.92 (4)
H4A—C4—H4B	109.5	O1—V1—O2^i	99.92 (4)
C1—C4—H4C	109.5	O2—V1—O2^i	160.16 (8)
H4A—C4—H4C	109.5	O1—V1—O3	98.30 (4)
H4B—C4—H4C	109.5	O2—V1—O3	89.55 (5)
C3—C5—H5A	109.5	O2^i—V1—O3	87.60 (5)
C3—C5—H5B	109.5	O1—V1—O3^i	98.30 (4)
H5A—C5—H5B	109.5	O2—V1—O3^i	87.60 (5)
C3—C5—H5C	109.5	O2^i—V1—O3^i	89.55 (5)
H5A—C5—H5C	109.5	O3—V1—O3^i	163.39 (8)
H5B—C5—H5C	109.5	O1—V1—N1	180
N1—C6—C7	123.16 (19)	O2—V1—N1	80.08 (4)
N1—C6—H6	118.4	O2^i—V1—N1	80.08 (4)
C7—C6—H6	118.4	O3—V1—N1	81.70 (4)
C8—C7—C6	119.0 (2)	O3^i—V1—N1	81.70 (4)
O3—C1—C2—C3	0.7 (4)	C3—O2—V1—O3^i	−166.86 (15)
C4—C1—C2—C3	−178.7 (2)	C3—O2—V1—N1	−84.87 (15)
C1—C2—C3—O2	1.0 (4)	C1—O3—V1—O1	−95.23 (15)
C1—C2—C3—C5	−179.3 (2)	C1—O3—V1—O2	4.73 (15)
N1—C6—C7—C8	−0.6 (3)	C1—O3—V1—O2^i	165.09 (15)
C6—C7—C8—C7^i	0.28 (12)	C1—O3—V1—O3^i	84.77 (15)
C7—C6—N1—C6^i	0.30 (13)	C1—O3—V1—N1	84.77 (15)
C7—C6—N1—V1	−179.70 (13)	C6—N1—V1—O2	133.93 (10)
C2—C3—O2—V1	1.2 (3)	C6^i—N1—V1—O2	−46.07 (10)
C5—C3—O2—V1	−178.52 (13)	C6—N1—V1—O2^i	−46.07 (10)
C2—C1—O3—V1	−4.3 (3)	C6^i—N1—V1—O2^i	133.93 (10)
C4—C1—O3—V1	175.11 (14)	C6—N1—V1—O3	42.93 (10)
C3—O2—V1—O1	95.13 (15)	C6^i—N1—V1—O3	−137.07 (10)
C3—O2—V1—O2^i	−84.87 (15)	C6—N1—V1—O3^i	−137.07 (10)
C3—O2—V1—O3	−3.22 (15)	C6^i—N1—V1—O3^i	42.93 (10)

Symmetry code: (i) −x+1, y, −z+3/2.