Piperazinium aqua­bis(oxalato)­oxido­vanadate(IV) dihydrate

The title compound, (C₄H₁₂N₂)[V(C₂O₄)₂O(H₂O)]·2H₂O, has been obtained by the reaction of vanadium(III) chloride with piperazinediium oxalate in aqueous solution. It shows distorted octahedral geometry [V=O = 1.6010 (12) Å and V—O = 1.9932 (12)–2.2176 (12) Å]]. The structure exhibits intermolecular N—H...O and C—H...O hydrogen bonds. The uncoordinated water mol­ecules contribute to the formation of the supra­molecular structure via O—H...O hydrogen bonds.

Key indicators

• Single-crystal X-ray study
• T = 100 K
• Mean [sigma](C-C) = 0.003 Å
• R factor = 0.039
• wR factor = 0.103
• Data-to-parameter ratio = 24.0

checkCIF/PLATON results

No syntax errors found



Alert level C
PLAT232_ALERT_2_C Hirshfeld Test Diff (M-X)  V1     -   O1      ..       5.09 su
PLAT369_ALERT_2_C Long   C(sp2)-C(sp2) Bond  C1     -   C2     ...       1.55 Ang.
PLAT369_ALERT_2_C Long   C(sp2)-C(sp2) Bond  C3     -   C4     ...       1.55 Ang.
PLAT417_ALERT_2_C Short Inter D-H..H-D       H1WB   ..  H10B    ..       2.11 Ang.
PLAT720_ALERT_4_C Number of Unusual/Non-Standard Label(s) ........          4

Alert level G
PLAT794_ALERT_5_G Check Predicted Bond Valency for V1          (4)       4.10

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

   0 ALERT type 1 CIF construction/syntax error, inconsistent or missing data
   4 ALERT type 2 Indicator that the structure model may be wrong or deficient
   0 ALERT type 3 Indicator that the structure quality may be low
   1 ALERT type 4 Improvement, methodology, query or suggestion
   1 ALERT type 5 Informative message, check

---

S1. Comment

Hydrogen bonding plays a key role in chemical, catalytic and biochemical processes, as well as in supramolecular chemistry and crystal engineering. In order to study the hydrogen-bonding patterns in proton-transfer compounds, our research group has selected pyridine-2,6-dicarboxylic acid (pydcH₂) and 1,10-phenanthroline-2,9-dicarboxylic acid (phendcH₂) as proton donors, and pyridine-2,6-diamine (pyda), creatinine (creat) and 1,10-phenanthroline (phen) as proton acceptors. This has resulted in the formation of new proton-transfer systems, such as (pydaH)(pydcH) (Aghabozorg et al., 2005), (creatH)(pydcH) (Moghimi et al., 2005) and (creatH)(phendcH) (Soleimannejad et al., 2005).

The molecular structure of the title compound, (I), is iven in Fig. 1. The asymmetric unit of the (pipzH₂)[V(O)(ox)₂].2H₂O compound contains [V(O)(ox)₂]^2– complex anions, two water molecules and (pipzH₂)²⁺ cations.

In this article, our goal was the generation of the self-assembling coordination compound using a self-assembling ligand. The structure of the V(IV) complex [VO(C₂O₄)₂(H₂O)]^2–[C₄H₁₂N₂]²⁺.1.5H₂O, was reported recentely (Lin et al., 2004), but the goal and method of synthesis were completely different from ours. The data collection temperature in our work was 100 K, whereas, the previous work was conducted at room temperature. In the present study the measured reflections was 3891, while in the earlier work it was 2183. It is necessary to mention that the structure of the V(IV) complex [VO(C₂O₄)₂(H₂O)]^2–[C₄H₁₂N₂]²⁺.2H₂O, (I), contains two uncoordinated water molecules without any disordering atoms but in the previous work, all uncoordinated water molecules were disorder. Therefore, The uncoordinated water molecules contribute to the formation of supramolecular structure via O—H···O hydrogen bonds.

The V1—O9 bond length [1.6014 (12) Å] is shorter than the other V—O bond lengths probably due to the formation of double bond. O1 and O9 atoms occupy the axial positions, [O1—V1—O9 is 170.19 (5)°], while O3, O5, O7 and O10 atoms form the equatorial plane. Therefore the coordination around the central atom is distorted octahedral. The O1—V1—O7—C3 and O5—V1—O3—C2 torsion angles are -93.97 (11)° and -84.46 (12)°, respectively, indicating that two dianionic (ox)^2– units are almost perpendicular to each other. A remarkable feature in the crystal structure of compound (I) is the presence of O—H···O, O—H···N and C—H···O hydrogen bonds with D···A distances ranging from 2.60 (2) Å to 3.442 (2) Å (Table 1). Hydrogen bonds result in the formation of a supramolecular structure (Fig. 2). Ion pairing and van der Waals interactions are also effective in the packing.

Related literature

New proton-transfer compounds, which may contain pyridine-2,6-dicarboxylic acid (pydcH₂), pyridine-2,6-diamine (pyda) and creatine, are discussed by Aghabozorg et al. (2005), Moghimi et al. (2005) and Soleimannejad et al. (2005). A five-coordinated vanadium(V) complex with a (pydcH)(pydaH) proton-transfer compound was previously reported by Ranjbar (2004). Another five-coordinated self-assembled complex, (dmpH)[V(pydc)(O)₂].H₂O (dmp = 2,9-dimethyl-1,10-phenanthroline) was reported by Aghabozorg & Sadr-khanlou (2007).

S2. Experimental

A solution of VCl₃ (80 mg, 0.5 mmol) in water (20 ml) was added to an aqueous solution of piperazinediium oxalate (176 mg, 1.0 mmol in water (20 ml) in a 2:1 molar ratio. Blue crystals of (I) were obtained after a few days at room temperature.

S3. Refinement

All hydrogen atoms were found in difference Fourier synthesis, placed in idealized positions (C—H 0.99 Å, N—H 0.92 Å, O—H 0.85 Å) and refined in isotropic approximatiom as riding with U_iso(H) = 1.2 U_eq(parent atom). The highest residual peak [1.26 e Å^-3] is situated 0.83 Å at atom V1.

Computing details

Data collection: APEX2 (Bruker, 2005); cell refinement: APEX2; data reduction: APEX2; program(s) used to solve structure: SHELXTL (Sheldrick, 1998); program(s) used to refine structure: SHELXTL; molecular graphics: SHELXTL; software used to prepare material for publication: SHELXTL.

Figures

	Fig. 1. The asymmetric unit of (pipzH2)[V(O)(ox)2].2H2O, with displacement ellipsoids drawn at the 50% probability level.
	Fig. 2. The crystal packing of (pipzH2)[V(O)(ox)2].2H2O, hydrogen bonds are shown as dashed lines.

Piperazinium aquabis(oxalato)oxidovanadate(IV) dihydrate

Crystal data

(C4H12N2)[V(C2O4)2O(H2O)]·2H2O	F(000) = 796
Mr = 385.18	Dx = 1.757 Mg m^−3
Monoclinic, P21/n	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2yn	Cell parameters from 3837 reflections
a = 10.0302 (6) Å	θ = 2.3–32.9°
b = 12.4995 (8) Å	µ = 0.75 mm^−1
c = 12.4665 (8) Å	T = 100 K
β = 111.320 (1)°	Plate, blue
V = 1455.99 (16) Å^3	0.60 × 0.12 × 0.06 mm
Z = 4

Data collection

Bruker SMART APEX II CCD area-detector diffractometer	4983 independent reflections
Radiation source: fine-focus sealed tube	3891 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.038
ω scans	θmax = 32.0°, θmin = 2.3°
Absorption correction: multi-scan (APEX2; Bruker, 2005)	h = −14→14
Tmin = 0.662, Tmax = 0.956	k = −18→17
16128 measured reflections	l = −18→18

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: difference Fourier map
wR(F^2) = 0.103	H-atom parameters constrained
S = 1.02	w = 1/[σ^2(Fo^2) + (0.0478P)^2 + 0.8P] where P = (Fo^2 + 2Fc^2)/3
4983 reflections	(Δ/σ)max = 0.001
208 parameters	Δρmax = 1.26 e Å^−3
0 restraints	Δρmin = −0.75 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
V1	0.61163 (3)	0.93971 (2)	0.85255 (2)	0.00815 (7)
O1	0.69720 (12)	0.80761 (10)	0.77764 (10)	0.0112 (2)
O2	0.64764 (13)	0.71346 (10)	0.61456 (10)	0.0135 (2)
O3	0.46500 (12)	0.92058 (9)	0.69221 (10)	0.0118 (2)
O4	0.40975 (13)	0.84269 (10)	0.52017 (10)	0.0140 (2)
O5	0.53646 (12)	0.81507 (9)	0.91695 (10)	0.0109 (2)
O6	0.58704 (13)	0.71576 (10)	1.07578 (10)	0.0138 (2)
O7	0.78005 (12)	0.91467 (9)	0.99668 (10)	0.0111 (2)
O8	0.83600 (12)	0.83993 (10)	1.17084 (10)	0.0136 (2)
O9	0.52951 (13)	1.03699 (10)	0.88501 (10)	0.0139 (2)
O10	0.74368 (13)	1.02457 (10)	0.79444 (10)	0.0133 (2)
H10A	0.7735	1.0872	0.8175	0.016*
H10B	0.7438	1.0175	0.7266	0.016*
C1	0.62181 (16)	0.78455 (13)	0.67431 (14)	0.0099 (3)
C2	0.48584 (16)	0.85416 (13)	0.62224 (13)	0.0098 (3)
C3	0.75798 (16)	0.85130 (13)	1.06993 (13)	0.0097 (3)
C4	0.61588 (16)	0.78749 (13)	1.01984 (13)	0.0099 (3)
N1	0.24180 (15)	0.78431 (11)	0.81510 (12)	0.0111 (3)
H1A	0.3395	0.7798	0.8356	0.013*
H1B	0.2015	0.7859	0.7360	0.013*
N2	−0.00704 (14)	0.79569 (11)	0.87667 (12)	0.0112 (3)
H2A	−0.1047	0.8001	0.8562	0.013*
H2B	0.0334	0.7932	0.9557	0.013*
C5	0.18936 (18)	0.68788 (14)	0.85840 (15)	0.0142 (3)
H5A	0.2377	0.6827	0.9430	0.017*
H5B	0.2122	0.6226	0.8235	0.017*
C6	0.02939 (18)	0.69603 (14)	0.82766 (15)	0.0141 (3)
H6A	−0.0191	0.6964	0.7429	0.017*
H6B	−0.0050	0.6330	0.8583	0.017*
C7	0.04559 (18)	0.89219 (14)	0.83438 (15)	0.0137 (3)
H7A	0.0239	0.9569	0.8708	0.016*
H7B	−0.0044	0.8986	0.7500	0.016*
C8	0.20546 (17)	0.88496 (13)	0.86239 (15)	0.0126 (3)
H8A	0.2375	0.9473	0.8291	0.015*
H8B	0.2561	0.8867	0.9469	0.015*
O1W	0.74471 (15)	0.98447 (11)	0.58954 (12)	0.0207 (3)
H1WA	0.8212	1.0015	0.5792	0.025*
H1WB	0.6957	1.0349	0.5479	0.025*
O2W	1.01439 (16)	1.05116 (12)	0.61212 (13)	0.0271 (3)
H2WA	0.9990	1.0873	0.5510	0.033*
H2WB	1.0365	1.0950	0.6680	0.033*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
V1	0.00938 (12)	0.00690 (12)	0.00767 (12)	0.00021 (9)	0.00249 (9)	−0.00027 (9)
O1	0.0105 (5)	0.0120 (5)	0.0095 (5)	0.0015 (4)	0.0016 (4)	−0.0012 (4)
O2	0.0161 (5)	0.0123 (6)	0.0107 (5)	0.0052 (4)	0.0031 (4)	−0.0010 (4)
O3	0.0129 (5)	0.0104 (5)	0.0105 (5)	0.0030 (4)	0.0021 (4)	−0.0013 (4)
O4	0.0146 (5)	0.0152 (6)	0.0094 (5)	0.0032 (5)	0.0010 (4)	−0.0013 (4)
O5	0.0100 (5)	0.0115 (5)	0.0098 (5)	−0.0017 (4)	0.0020 (4)	0.0007 (4)
O6	0.0165 (5)	0.0118 (6)	0.0124 (5)	−0.0026 (4)	0.0045 (4)	0.0013 (4)
O7	0.0115 (5)	0.0102 (5)	0.0100 (5)	−0.0020 (4)	0.0019 (4)	0.0009 (4)
O8	0.0137 (5)	0.0155 (6)	0.0095 (5)	−0.0007 (4)	0.0017 (4)	0.0012 (4)
O9	0.0182 (6)	0.0126 (6)	0.0113 (5)	0.0031 (5)	0.0057 (4)	−0.0007 (4)
O10	0.0182 (6)	0.0104 (5)	0.0122 (5)	−0.0039 (5)	0.0066 (4)	−0.0007 (4)
C1	0.0106 (6)	0.0085 (7)	0.0110 (7)	−0.0001 (5)	0.0043 (5)	0.0004 (5)
C2	0.0108 (6)	0.0085 (7)	0.0098 (7)	0.0003 (5)	0.0034 (5)	0.0008 (5)
C3	0.0115 (6)	0.0065 (6)	0.0116 (7)	0.0005 (5)	0.0047 (5)	−0.0009 (5)
C4	0.0108 (6)	0.0093 (7)	0.0103 (7)	−0.0009 (5)	0.0045 (5)	−0.0023 (5)
N1	0.0112 (6)	0.0112 (6)	0.0111 (6)	−0.0017 (5)	0.0042 (5)	−0.0026 (5)
N2	0.0098 (6)	0.0130 (6)	0.0105 (6)	−0.0007 (5)	0.0035 (5)	0.0009 (5)
C5	0.0152 (7)	0.0103 (7)	0.0188 (8)	0.0008 (6)	0.0082 (6)	0.0009 (6)
C6	0.0152 (7)	0.0123 (7)	0.0162 (7)	−0.0043 (6)	0.0072 (6)	−0.0028 (6)
C7	0.0131 (7)	0.0120 (8)	0.0154 (7)	0.0002 (6)	0.0046 (6)	0.0022 (6)
C8	0.0127 (7)	0.0096 (7)	0.0160 (7)	−0.0024 (6)	0.0057 (6)	−0.0032 (6)
O1W	0.0223 (6)	0.0201 (7)	0.0199 (6)	0.0026 (5)	0.0078 (5)	0.0044 (5)
O2W	0.0272 (7)	0.0257 (8)	0.0260 (7)	−0.0023 (6)	0.0067 (6)	0.0034 (6)

Geometric parameters (Å, º)

V1—O9	1.6010 (12)	N1—H1A	0.9200
V1—O7	1.9932 (12)	N1—H1B	0.9200
V1—O3	2.0194 (12)	N2—C7	1.488 (2)
V1—O5	2.0200 (12)	N2—C6	1.490 (2)
V1—O10	2.0253 (12)	N2—H2A	0.9200
V1—O1	2.2176 (12)	N2—H2B	0.9200
O1—C1	1.2672 (19)	C5—C6	1.512 (2)
O2—C1	1.2458 (19)	C5—H5A	0.9900
O3—C2	1.2753 (19)	C5—H5B	0.9900
O4—C2	1.2313 (19)	C6—H6A	0.9900
O5—C4	1.2867 (19)	C6—H6B	0.9900
O6—C4	1.2331 (19)	C7—C8	1.515 (2)
O7—C3	1.2873 (19)	C7—H7A	0.9900
O8—C3	1.2245 (19)	C7—H7B	0.9900
O10—H10A	0.8500	C8—H8A	0.9900
O10—H10B	0.8501	C8—H8B	0.9900
C1—C2	1.547 (2)	O1W—H1WA	0.8500
C3—C4	1.553 (2)	O1W—H1WB	0.8500
N1—C8	1.490 (2)	O2W—H2WA	0.8500
N1—C5	1.492 (2)	O2W—H2WB	0.8501
O9—V1—O7	103.69 (6)	C5—N1—H1A	109.3
O9—V1—O3	94.80 (6)	C8—N1—H1B	109.3
O7—V1—O3	161.31 (5)	C5—N1—H1B	109.3
O9—V1—O5	100.64 (6)	H1A—N1—H1B	107.9
O7—V1—O5	80.63 (5)	C7—N2—C6	111.16 (12)
O3—V1—O5	93.40 (5)	C7—N2—H2A	109.4
O9—V1—O10	98.98 (6)	C6—N2—H2A	109.4
O7—V1—O10	87.39 (5)	C7—N2—H2B	109.4
O3—V1—O10	92.50 (5)	C6—N2—H2B	109.4
O5—V1—O10	158.94 (5)	H2A—N2—H2B	108.0
O9—V1—O1	170.19 (5)	N1—C5—C6	109.58 (14)
O7—V1—O1	86.09 (5)	N1—C5—H5A	109.8
O3—V1—O1	75.47 (4)	C6—C5—H5A	109.8
O5—V1—O1	81.41 (5)	N1—C5—H5B	109.8
O10—V1—O1	80.55 (5)	C6—C5—H5B	109.8
C1—O1—V1	114.72 (10)	H5A—C5—H5B	108.2
C2—O3—V1	120.84 (10)	N2—C6—C5	110.38 (13)
C4—O5—V1	114.68 (10)	N2—C6—H6A	109.6
C3—O7—V1	115.35 (10)	C5—C6—H6A	109.6
V1—O10—H10A	123.9	N2—C6—H6B	109.6
V1—O10—H10B	122.6	C5—C6—H6B	109.6
H10A—O10—H10B	107.7	H6A—C6—H6B	108.1
O2—C1—O1	126.38 (15)	N2—C7—C8	110.62 (13)
O2—C1—C2	119.56 (14)	N2—C7—H7A	109.5
O1—C1—C2	114.06 (13)	C8—C7—H7A	109.5
O4—C2—O3	126.05 (15)	N2—C7—H7B	109.5
O4—C2—C1	119.26 (14)	C8—C7—H7B	109.5
O3—C2—C1	114.69 (13)	H7A—C7—H7B	108.1
O8—C3—O7	126.14 (15)	N1—C8—C7	110.49 (13)
O8—C3—C4	120.25 (14)	N1—C8—H8A	109.6
O7—C3—C4	113.60 (13)	C7—C8—H8A	109.6
O6—C4—O5	124.83 (15)	N1—C8—H8B	109.6
O6—C4—C3	121.06 (14)	C7—C8—H8B	109.6
O5—C4—C3	114.10 (13)	H8A—C8—H8B	108.1
C8—N1—C5	111.70 (13)	H1WA—O1W—H1WB	94.3
C8—N1—H1A	109.3	H2WA—O2W—H2WB	107.5
O7—V1—O1—C1	178.77 (11)	V1—O3—C2—O4	−173.53 (13)
O3—V1—O1—C1	1.87 (11)	V1—O3—C2—C1	5.61 (18)
O5—V1—O1—C1	97.68 (11)	O2—C1—C2—O4	−4.5 (2)
O10—V1—O1—C1	−93.22 (11)	O1—C1—C2—O4	175.62 (15)
O9—V1—O3—C2	174.56 (12)	O2—C1—C2—O3	176.33 (14)
O7—V1—O3—C2	−13.9 (2)	O1—C1—C2—O3	−3.6 (2)
O5—V1—O3—C2	−84.45 (12)	V1—O7—C3—O8	−165.78 (13)
O10—V1—O3—C2	75.33 (12)	V1—O7—C3—C4	13.14 (16)
O1—V1—O3—C2	−4.23 (12)	V1—O5—C4—O6	177.67 (13)
O9—V1—O5—C4	−94.07 (11)	V1—O5—C4—C3	−3.75 (16)
O7—V1—O5—C4	8.23 (11)	O8—C3—C4—O6	−8.6 (2)
O3—V1—O5—C4	170.40 (11)	O7—C3—C4—O6	172.46 (14)
O10—V1—O5—C4	64.38 (19)	O8—C3—C4—O5	172.80 (15)
O1—V1—O5—C4	95.66 (11)	O7—C3—C4—O5	−6.18 (19)
O9—V1—O7—C3	86.73 (12)	C8—N1—C5—C6	57.49 (18)
O3—V1—O7—C3	−84.57 (18)	C7—N2—C6—C5	58.11 (17)
O5—V1—O7—C3	−12.04 (11)	N1—C5—C6—N2	−57.67 (18)
O10—V1—O7—C3	−174.66 (11)	C6—N2—C7—C8	−56.69 (17)
O1—V1—O7—C3	−93.97 (11)	C5—N1—C8—C7	−56.48 (18)
V1—O1—C1—O2	−179.70 (13)	N2—C7—C8—N1	55.37 (18)
V1—O1—C1—C2	0.21 (16)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
N1—H1A···O5	0.92	1.92	2.787 (2)	157
N1—H1B···O6^i	0.92	1.91	2.818 (2)	170
N2—H2A···O1^ii	0.92	1.87	2.772 (2)	166
N2—H2B···O2^iii	0.92	1.89	2.805 (2)	170
O10—H10A···O2^iv	0.85	1.83	2.674 (2)	172
O10—H10B···O1W	0.85	1.77	2.607 (2)	172
O1W—H1WA···O2W	0.85	1.93	2.745 (2)	160
O1W—H1WB···O4^v	0.85	1.88	2.720 (2)	170
O2W—H2WA···O6^iv	0.85	2.20	3.004 (2)	158
O2W—H2WB···O8^vi	0.85	2.11	2.911 (2)	156
C6—H6A···O9^vii	0.99	2.53	3.192 (2)	124
C6—H6B···O4^iii	0.99	2.48	3.087 (2)	119
C8—H8B···O9^viii	0.99	2.58	3.442 (2)	146

Symmetry codes: (i) x−1/2, −y+3/2, z−1/2; (ii) x−1, y, z; (iii) x−1/2, −y+3/2, z+1/2; (iv) −x+3/2, y+1/2, −z+3/2; (v) −x+1, −y+2, −z+1; (vi) −x+2, −y+2, −z+2; (vii) −x+1/2, y−1/2, −z+3/2; (viii) −x+1, −y+2, −z+2.