Piperazinium chromate(VI)

The structure of the title complex, (C₄H₁₂N₂)[CrO₄], consists of tetrahedral [CrO₄]^2- dianions which are connected to the cyclic organic piperazinium dications via hydrogen bonding. All the atoms are located in general positions.

Key indicators

• Single-crystal X-ray study
• T = 293 K
• Mean [sigma](C-C) = 0.002 Å
• R factor = 0.026
• wR factor = 0.082
• Data-to-parameter ratio = 23.3

checkCIF results

No syntax errors found

ADDSYM reports no extra symmetry

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Computing details

Data collection: DIF4 (Stoe & Cie, 1992); cell refinement: DIF4; data reduction: REDU4 (Stoe & Cie, 1992); program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: XP in SHELXTL (Bruker, 1998); software used to prepare material for publication: CIFTAB in SHELXTL.

Piperazinium chromate(VI)

Crystal data

C4H12N2^2+·O4Cr^2^−	F(000) = 424
Mr = 204.16	Dx = 1.688 Mg m^−3
Monoclinic, P21/n	Mo Kα radiation, λ = 0.71073 Å
a = 7.6651 (9) Å	Cell parameters from 105 reflections
b = 12.3726 (18) Å	θ = 16–20°
c = 8.4886 (10) Å	µ = 1.40 mm^−1
β = 93.766 (12)°	T = 293 K
V = 803.30 (18) Å^3	Block, yellow
Z = 4	0.18 × 0.12 × 0.08 mm

Data collection

Stoe AED-II four-circle diffractometer	2034 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tube	Rint = 0.035
Graphite monochromator	θmax = 30.0°, θmin = 2.9°
ω scans	h = −10→1
Absorption correction: numerical (X-SHAPE and X-RED; Stoe & Cie, 1998)	k = −17→9
Tmin = 0.810, Tmax = 0.894	l = −11→11
4578 measured reflections	4 standard reflections every 120 min
2350 independent reflections	intensity decay: none

Refinement

Refinement on F^2	Secondary atom site location: difference Fourier map
Least-squares matrix: full	Hydrogen site location: inferred from neighbouring sites
R[F^2 > 2σ(F^2)] = 0.026	H-atom parameters constrained
wR(F^2) = 0.082	w = 1/[σ^2(Fo^2) + (0.0429P)^2 + 0.3211P] where P = (Fo^2 + 2Fc^2)/3
S = 1.06	(Δ/σ)max < 0.001
2350 reflections	Δρmax = 0.36 e Å^−3
101 parameters	Δρmin = −0.52 e Å^−3
0 restraints	Extinction correction: SHELXL97, Fc^*=kFc[1+0.001xFc^2λ^3/sin(2θ)]^-1/4
Primary atom site location: structure-invariant direct methods	Extinction coefficient: 0.105 (5)

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
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 (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
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)
N2	0.0330 (6)	0.0370 (7)	0.0285 (6)	0.0144 (6)	−0.0009 (5)	−0.0042 (6)
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···O1^i	0.90	1.78	2.6697 (18)	169
N1—H2N1···O2^ii	0.90	1.81	2.7009 (18)	173
N2—H1N2···O3	0.90	1.83	2.709 (2)	164
N2—H2N2···O2^iii	0.90	2.19	2.9133 (19)	137
N2—H2N2···O1^iii	0.90	2.22	2.9014 (19)	132

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