Acta Cryst.(2003). E59, m639±m641 DOI: 10.1107/S1600536803014879 Bikshandarkoil R. Srinivasanet al. C4H12N22+O4Cr2ÿ
m639
metal-organic papers
Acta Crystallographica Section E Structure Reports
Online
ISSN 1600-5368
Piperazinium chromate(VI)
Bikshandarkoil R. Srinivasan,a
Christian NaÈtherb* and Wolfgang
Benschb
aDepartment of Chemistry, Goa University PO,
Goa 403 206, India, andbInstitut fuÈr
Anorganische Chemie, Christian-Albrechts-UniversitaÈt Kiel, Olshausenstraûe 40, D-24098 Kiel, Germany
Correspondence e-mail: cnaether@ac.uni-kiel.de
Key indicators Single-crystal X-ray study
T= 293 K
Mean(C±C) = 0.002 AÊ
Rfactor = 0.026
wRfactor = 0.082
Data-to-parameter ratio = 23.3
For details of how these key indicators were automatically derived from the article, see http://journals.iucr.org/e.
#2003 International Union of Crystallography Printed in Great Britain ± all rights reserved
The structure of the title complex, (C4H12N2)[CrO4], consists
of tetrahedral [CrO4]2ÿdianions which are connected to the
cyclic organic piperazinium dicationsvia hydrogen bonding. All the atoms are located in general positions.
Comment
The present structural description of piperazinium chromate constitutes a part of our ongoing investigations of compounds resulting from the interaction of organic diamines with group 6 oxo- and thiometalates. Among the investigated complexes we have previously described the structures of ethylenedi-ammonium tetrathiomolybdate (Srinivasan et al., 2001), ethylenediamonium tetrathiotungstate (Srinivasan et al., 2002), 1,3-propanediammonium tetrathiotungstate, N,N,-N0,N0-tetramethylethylenediammonium tetrathiotungstate (Srinivasanet al., 2003a) and ethylenediammonium chromate (Srinivasanet al., 2003b). Some examples of chromates bound to organic cations, such as 2,2-dimethyl-1,3-propanedi-ammonium chromate (Chebbi et al., 2000), 4-ammonio-2,2,6,6,-tetramethylpiperidinium chromate (Chebbi & Driss, 2001), 1,4-butanediammonium chromate (Chebbi & Driss, 2002a) and bis(2-methyl-2-propanammonium) chromate (Chebbi & Driss, 2002b), have also been reported in the recent literature. The extensive use of CrVIcompounds in
combina-tion with organic amines in organic synthesis is one reason for the continued interest in this ®eld. The base-promoted cation exchange reactions developed by us for the synthesis of the sul®de complexes of Mo and W mentioned above can also be used for the synthesis of oxochromates. Thus the title complex, (I), was obtained in good yields by reacting the cyclic diamine piperazine with ammonium chromate.
The structure of (I) consists of tetrahedral [CrO4]2ÿ
dianions and piperazinium dications (Fig. 1). As expected, the piperazinium dication adopts the chair conformation, with internal bond lengths and bond angles (Table 1) in the ranges usually observed in this form (Tran Qui & Palacios, 1990; Tyrselova et al., 1996). The CrO4 tetrahedron in (I) is
distorted, with OÐCrÐO angles ranging from 107.07 (6) to 111.27 (8) (Table 1). The CrÐO bond distances vary from
metal-organic papers
m640
Bikshandarkoil R. Srinivasanet al. C4H12N22+O4Cr2ÿ Acta Cryst.(2003). E59, m639±m641 1.6176 (14) to 1.6631 (12) AÊ, with a mean CrÐO bond lengthof 1.6468 AÊ. This value is generally observed for this type of tetrahedron (Barset al., 1977; Braueret al., 1991; Chebbiet al., 2000; Chebbi & Driss, 2002a). The maximum difference in O O distances in (I) is 0.034 AÊ. This value is of the same order as that observed in (NaNH4)[CrO4] (0.030 AÊ; Khan &
Baur, 1972), in (C4H14N2)[CrO4] (0.037 AÊ; Chebbi & Driss,
2002a) and in (CH6N3)2[CrO4] (0.040 AÊ; Cygleret al., 1976).
In the crystal structure, the anions and cations are connected via NÐH O hydrogen bonding between the O atoms of the chromate dianions and the H atoms of the N atoms. Each chromate is connected to ®ve piperazinium cations, forming a three-dimensional hydrogen-bonding network (Fig. 2). The deformation of the chromate tetra-hedron in (I) is related to the hydrogen bonding interactions. A dependence of the CrÐO distances upon the strength of hydrogen bonds formed has been found in the title complex, with short hydrogen-bonding contacts ranging from 1.78 to 2.22 AÊ (Table 2). Atom O1, which forms two short hydrogen bonds with an average N O distance of 2.785 AÊ, corresponds to the longest CrÐO distance [1.6631 (12) AÊ], while atom O4, which is not involved in any hydrogen bonding, shows the
shortest CrÐO bond length [1.6176 (14) AÊ]. Intermediate CrÐO distances of 1.6451 (12) and 1.6617 (12) AÊ, respec-tively, are found for O3, which has a single H O contact, and O2, which makes two contacts with an average N O distance of 2.807 AÊ. In chromates bound to acyclic organic di-ammonium cations such as 1,4-butanedidi-ammonium, 2,2-di-methyl-1,3-propanediammonium and ethylenediammonium, longer CrÐO distances than in (I) have been reported.
Experimental
(NH4)2[CrO4] (5 mmol) was dissolved in 10 ml distilled water and anhydrous piperazine (5 mmol) was added. The solution was stirred well and ®ltered. The clear yellow ®ltrate was left undisturbed. After a few days, yellow blocks of the title compound crystallized. The crystals were washed with ice-cold water (1 ml), and dried in air. Yield 70% based on Cr. The crystals are stable in air. Analysis calculated for C4H12CrN2O4: C 23.53, H 5.94, N 13.72%; found: C 23.58, H 5.94, N 13.59%.
Crystal data C4H12N22+O4Cr2ÿ Mr= 204.16
Monoclinic,P21=n a= 7.6651 (9) AÊ
b= 12.3726 (18) AÊ
c= 8.4886 (10) AÊ
= 93.766 (12)
V= 803.30 (18) AÊ3 Z= 4
Dx= 1.688 Mg mÿ3
MoKradiation Cell parameters from 105
re¯ections
= 16±20
= 1.40 mmÿ1 T= 293 (2) K Block, yellow 0.180.120.08 mm Data collection
Stoe AED-II four-circle diffractometer
!scans
Absorption correction: numerical (X-SHAPEandX-RED; Stoe & Cie, 1998)
Tmin= 0.810,Tmax= 0.894
4578 measured re¯ections 2350 independent re¯ections
2034 re¯ections withI> 2(I)
Rint= 0.035 max= 30.0 h=ÿ10!1
k=ÿ17!9
l=ÿ11!11 4 standard re¯ections
frequency: 120 min intensity decay: none Re®nement
Re®nement onF2 R[F2> 2(F2)] = 0.026 wR(F2) = 0.082 S= 1.06 2350 re¯ections 101 parameters
H-atom parameters constrained
w= 1/[2(F
o2) + (0.0429P)2
+ 0.3211P]
whereP= (Fo2+ 2Fc2)/3
(/)max< 0.001
max= 0.36 e AÊÿ3
min=ÿ0.52 e AÊÿ3
Extinction correction:SHELXL97 Extinction coef®cient: 0.105 (5)
Table 1
Selected geometric parameters (AÊ,).
Cr1ÐO4 1.6176 (14) Cr1ÐO3 1.6451 (12) Cr1ÐO2 1.6617 (12) Cr1ÐO1 1.6631 (12) N1ÐC4 1.476 (2)
N1ÐC1 1.490 (2) C1ÐC2 1.503 (2) C2ÐN2 1.486 (2) N2ÐC3 1.486 (2) C3ÐC4 1.508 (2)
O4ÐCr1ÐO3 111.27 (8) O4ÐCr1ÐO2 109.97 (7) O3ÐCr1ÐO2 109.96 (7) O4ÐCr1ÐO1 109.23 (8) O3ÐCr1ÐO1 109.25 (6) O2ÐCr1ÐO1 107.07 (6)
C4ÐN1ÐC1 112.01 (12) N1ÐC1ÐC2 109.36 (13) N2ÐC2ÐC1 110.52 (14) C2ÐN2ÐC3 111.48 (12) N2ÐC3ÐC4 109.94 (13) N1ÐC4ÐC3 110.10 (14)
Figure 2
The crystal structure of piperazinium chromate, viewed along thebaxis (intermolecular hydrogen bonding is shown as dashed lines).
Figure 1
Table 2
Hydrogen-bonding geometry (AÊ,).
DÐH A DÐH H A D A DÐH A
N1ÐH1N1 O1i 0.90 1.78 2.6697 (18) 169
N1ÐH2N1 O2ii 0.90 1.81 2.7009 (18) 173
N2ÐH1N2 O3 0.90 1.83 2.709 (2) 164 N2ÐH2N2 O2iii 0.90 2.19 2.9133 (19) 137
N2ÐH2N2 O1iii 0.90 2.22 2.9014 (19) 132
Symmetry codes: (i)ÿx;2ÿy;1ÿz; (ii)x;y;1z; (iii)1
2x;32ÿy;12z.
The H atoms on C and N atoms were positioned with idealized geometry (CÐH = 0.97 AÊ and NÐH = 0.90 AÊ) and re®ned with ®xed isotropic displacement parameters according to a riding model [Uiso(H) = 1.2Ueq(Cmethylene/NÐH)].
Data collection:DIF4 (Stoe & Cie, 1992); cell re®nement:DIF4; data reduction:REDU4 (Stoe & Cie, 1992); program(s) used to solve structure:SHELXS97 (Sheldrick, 1997); program(s) used to re®ne structure:SHELXL97 (Sheldrick, 1997); molecular graphics:XPin
SHELXTL (Bruker, 1998); software used to prepare material for publication:CIFTABinSHELXTL.
This work is supported by the State of Schleswig-Holstein and the Deutsche Forschungsgemeinschaft. BRS thanks the Deutscher Akademischer Austauschdienst (DAAD), Bonn, for a visiting fellowship.
References
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Brauer, C., Jannin, M., Puget, R. & Perret, R. (1991).Acta Cryst.C47, 2231± 2232.
Bruker (1998). SHELXTL. Version 5.10. Bruker AXS Inc., Madison, Wisconsin, USA.
Chebbi, H. & Driss, A. (2001).Acta Cryst.C57, 1369±1370. Chebbi, H. & Driss, A. (2002a).Acta Cryst.E58, m147±m149. Chebbi, H. & Driss, A. (2002b).Acta Cryst.E58, m494±m496.
Chebbi, H., Hajem, A. A. & Driss, A. (2000).Acta Cryst.C56, e333±e334. Cygler, M., Grabowski, M. J., Stepien, A. & Wajsman, E. (1976).Acta Cryst.
B32, 2391±2395.
Khan, A. A. & Baur, W. H. (1972).Acta Cryst.B28, 683±693.
Sheldrick, G. M. (1997). SHELXS97 and SHELXL97. University of GoÈttingen, Germany.
Srinivasan, B. R., Dhuri, S. N., NaÈther, C. & Bensch, W. (2002).Acta Cryst.
E58, m622±m624.
Srinivasan, B. R., Dhuri, S. N., NaÈther, C. & Bensch, W. (2003a).Acta Cryst.
C59, m124±m127.
Srinivasan, B. R., Dhuri, S. N., NaÈther, C. & Bensch, W. (2003b).Indian J. Chem. Sect. A. In the press.
Srinivasan, B. R., Vernekar, B. K. & Nagarajan, K. (2001).Indian J. Chem. Sect. A,40, 563±567.
Stoe & Cie (1992).DIF4 (Version 7.09X/DOS) andREDU4 (Version 7.03). Stoe & Cie, Darmstadt, Germany.
Stoe & Cie (1998). X-SHAPE and X-RED. Version 1.03. Stoe & Cie, Darmstadt, Germany.
Tran Qui, D. & Palacios, E. (1990).Acta Cryst.C46, 1212±1215. TyrselovaÂ, J., Kuchta, L. & Pavelcik, F. (1996).Acta Cryst.C52, 17±19.
supporting information
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Acta Cryst. (2003). E59, m639–m641
supporting information
Acta Cryst. (2003). E59, m639–m641 [https://doi.org/10.1107/S1600536803014879]
Piperazinium chromate(VI)
Bikshandarkoil R. Srinivasan, Christian N
ä
ther and Wolfgang Bensch
Piperazinium chromate(VI)
Crystal data
C4H12N22+·O4Cr2−
Mr = 204.16
Monoclinic, P21/n
a = 7.6651 (9) Å b = 12.3726 (18) Å c = 8.4886 (10) Å β = 93.766 (12)° V = 803.30 (18) Å3
Z = 4
F(000) = 424 Dx = 1.688 Mg m−3
Mo Kα radiation, λ = 0.71073 Å Cell parameters from 105 reflections θ = 16–20°
µ = 1.40 mm−1
T = 293 K Block, yellow
0.18 × 0.12 × 0.08 mm
Data collection
Stoe AED-II four-circle diffractometer
Radiation source: fine-focus sealed tube Graphite monochromator
ω scans
Absorption correction: numerical
(X-SHAPE and X-RED; Stoe & Cie, 1998) Tmin = 0.810, Tmax = 0.894
4578 measured reflections
2350 independent reflections 2034 reflections with I > 2σ(I) Rint = 0.035
θmax = 30.0°, θmin = 2.9°
h = −10→1 k = −17→9 l = −11→11
4 standard reflections every 120 min intensity decay: none
Refinement
Refinement on F2
Least-squares matrix: full R[F2 > 2σ(F2)] = 0.026
wR(F2) = 0.082
S = 1.06 2350 reflections 101 parameters 0 restraints
Primary atom site location: structure-invariant direct methods
Secondary atom site location: difference Fourier map
Hydrogen site location: inferred from neighbouring sites
H-atom parameters constrained w = 1/[σ2(F
o2) + (0.0429P)2 + 0.3211P]
where P = (Fo2 + 2Fc2)/3
(Δ/σ)max < 0.001
Δρmax = 0.36 e Å−3
Δρmin = −0.52 e Å−3
Extinction correction: SHELXL97, Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4
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Acta Cryst. (2003). E59, m639–m641 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 (Å2)
x y z Uiso*/Ueq
Cr1 0.21819 (3) 0.910006 (19) 0.17835 (3) 0.02268 (10)
O1 0.03085 (15) 0.90257 (10) 0.26610 (15) 0.0314 (2)
O2 0.20805 (17) 0.81921 (11) 0.03380 (13) 0.0346 (3)
O3 0.38107 (15) 0.88111 (13) 0.30737 (14) 0.0392 (3)
O4 0.2389 (2) 1.02997 (12) 0.10613 (18) 0.0495 (4)
N1 0.14987 (18) 0.91284 (11) 0.74774 (15) 0.0270 (3)
H1N1 0.0788 0.9706 0.7508 0.032*
H2N1 0.1610 0.8842 0.8453 0.032*
C1 0.0691 (2) 0.83133 (14) 0.63617 (18) 0.0291 (3)
H1A 0.0490 0.8631 0.5321 0.035*
H1B −0.0426 0.8083 0.6719 0.035*
C2 0.1892 (2) 0.73577 (14) 0.6280 (2) 0.0328 (3)
H2A 0.2012 0.7006 0.7303 0.039*
H2B 0.1395 0.6841 0.5518 0.039*
N2 0.36406 (18) 0.77052 (13) 0.58131 (16) 0.0330 (3)
H1N2 0.3535 0.7987 0.4834 0.040*
H2N2 0.4349 0.7126 0.5793 0.040*
C3 0.4435 (2) 0.85223 (15) 0.6925 (2) 0.0343 (3)
H3A 0.5551 0.8755 0.6569 0.041*
H3B 0.4638 0.8204 0.7966 0.041*
C4 0.3232 (2) 0.94819 (14) 0.7014 (2) 0.0334 (3)
H4A 0.3729 0.9997 0.7780 0.040*
H4B 0.3110 0.9837 0.5994 0.040*
Atomic displacement parameters (Å2)
U11 U22 U33 U12 U13 U23
Cr1 0.02214 (14) 0.02577 (14) 0.01977 (13) −0.00299 (8) −0.00120 (8) 0.00162 (8)
O1 0.0264 (5) 0.0316 (6) 0.0369 (6) 0.0027 (4) 0.0064 (4) −0.0005 (5)
O2 0.0438 (7) 0.0370 (7) 0.0232 (5) −0.0006 (5) 0.0033 (5) −0.0036 (4)
O3 0.0258 (5) 0.0605 (9) 0.0304 (6) −0.0027 (5) −0.0055 (4) 0.0051 (6)
O4 0.0655 (9) 0.0360 (7) 0.0462 (7) −0.0165 (7) −0.0024 (7) 0.0122 (6)
N1 0.0289 (6) 0.0278 (6) 0.0245 (6) 0.0051 (5) 0.0034 (5) −0.0006 (5)
C1 0.0250 (6) 0.0326 (8) 0.0294 (7) −0.0016 (6) −0.0019 (5) 0.0018 (6)
C2 0.0413 (8) 0.0237 (7) 0.0324 (7) −0.0016 (6) −0.0048 (6) −0.0023 (6)
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Acta Cryst. (2003). E59, m639–m641
C3 0.0233 (7) 0.0395 (9) 0.0395 (8) 0.0018 (6) −0.0017 (6) −0.0024 (7)
C4 0.0314 (7) 0.0257 (7) 0.0432 (9) −0.0036 (6) 0.0031 (6) −0.0020 (7)
Geometric parameters (Å, º)
Cr1—O4 1.6176 (14) C2—N2 1.486 (2)
Cr1—O3 1.6451 (12) C2—H2A 0.9700
Cr1—O2 1.6617 (12) C2—H2B 0.9700
Cr1—O1 1.6631 (12) N2—C3 1.486 (2)
N1—C4 1.476 (2) N2—H1N2 0.9000
N1—C1 1.490 (2) N2—H2N2 0.9000
N1—H1N1 0.9000 C3—C4 1.508 (2)
N1—H2N1 0.9000 C3—H3A 0.9700
C1—C2 1.503 (2) C3—H3B 0.9700
C1—H1A 0.9700 C4—H4A 0.9700
C1—H1B 0.9700 C4—H4B 0.9700
O4—Cr1—O3 111.27 (8) N2—C2—H2B 109.5
O4—Cr1—O2 109.97 (7) C1—C2—H2B 109.5
O3—Cr1—O2 109.96 (7) H2A—C2—H2B 108.1
O4—Cr1—O1 109.23 (8) C2—N2—C3 111.48 (12)
O3—Cr1—O1 109.25 (6) C2—N2—H1N2 109.3
O2—Cr1—O1 107.07 (6) C3—N2—H1N2 109.3
C4—N1—C1 112.01 (12) C2—N2—H2N2 109.3
C4—N1—H1N1 109.2 C3—N2—H2N2 109.3
C1—N1—H1N1 109.2 H1N2—N2—H2N2 108.0
C4—N1—H2N1 109.2 N2—C3—C4 109.94 (13)
C1—N1—H2N1 109.2 N2—C3—H3A 109.7
H1N1—N1—H2N1 107.9 C4—C3—H3A 109.7
N1—C1—C2 109.36 (13) N2—C3—H3B 109.7
N1—C1—H1A 109.8 C4—C3—H3B 109.7
C2—C1—H1A 109.8 H3A—C3—H3B 108.2
N1—C1—H1B 109.8 N1—C4—C3 110.10 (14)
C2—C1—H1B 109.8 N1—C4—H4A 109.6
H1A—C1—H1B 108.3 C3—C4—H4A 109.6
N2—C2—C1 110.52 (14) N1—C4—H4B 109.6
N2—C2—H2A 109.5 C3—C4—H4B 109.6
C1—C2—H2A 109.5 H4A—C4—H4B 108.2
Hydrogen-bond geometry (Å, º)
D—H···A D—H H···A D···A D—H···A
N1—H1N1···O1i 0.90 1.78 2.6697 (18) 169
N1—H2N1···O2ii 0.90 1.81 2.7009 (18) 173
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Acta Cryst. (2003). E59, m639–m641
N2—H2N2···O2iii 0.90 2.19 2.9133 (19) 137
N2—H2N2···O1iii 0.90 2.22 2.9014 (19) 132
