



Supporting information
![]() | Crystallographic Information File (CIF) https://doi.org/10.1107/S1600536812031042/bh2445sup1.cif |
![]() | Structure factor file (CIF format) https://doi.org/10.1107/S1600536812031042/bh2445Isup2.hkl |
CCDC reference: 896521
Key indicators
- Single-crystal X-ray study
- T = 293 K
- Mean
(C-C) = 0.002 Å
- R factor = 0.032
- wR factor = 0.096
- Data-to-parameter ratio = 35.2
checkCIF/PLATON results
No syntax errors found
Alert level B PLAT934_ALERT_3_B Number of (Iobs-Icalc)/SigmaW .gt. 10 Outliers . 1
Alert level C PLAT906_ALERT_3_C Large K value in the Analysis of Variance ...... 2.050 PLAT918_ALERT_3_C Reflection(s) # with I(obs) much smaller I(calc) 1
Alert level G PLAT005_ALERT_5_G No _iucr_refine_instructions_details in CIF .... ? PLAT007_ALERT_5_G Note: Number of Unrefined D-H Atoms ............ 3 PLAT153_ALERT_1_G The su's on the Cell Axes are Equal .......... 0.00200 Ang. PLAT199_ALERT_1_G Check the Reported _cell_measurement_temperature 293 K PLAT200_ALERT_1_G Check the Reported _diffrn_ambient_temperature 293 K PLAT764_ALERT_4_G Overcomplete CIF Bond List Detected (Rep/Expd) . 1.33 Ratio
0 ALERT level A = Most likely a serious problem - resolve or explain 1 ALERT level B = A potentially serious problem, consider carefully 2 ALERT level C = Check. Ensure it is not caused by an omission or oversight 6 ALERT level G = General information/check it is not something unexpected 3 ALERT type 1 CIF construction/syntax error, inconsistent or missing data 0 ALERT type 2 Indicator that the structure model may be wrong or deficient 3 ALERT type 3 Indicator that the structure quality may be low 1 ALERT type 4 Improvement, methodology, query or suggestion 2 ALERT type 5 Informative message, check
Single crystals of the title compound were prepared at room temperature by dissolving CrO3 (0.10 g, 1 mmol) and 1,3-diaminopropane (0.07 g, 1 mmol) in distilled water (20 ml). The resulting solution was stirred during 30 min. and then evaporated slowly at room temperature until the formation of orange prismatic single crystals.
All H atoms attached to C and N atoms were fixed geometrically and treated as riding with C—H = 0.97 Å (methylene) and N—H = 0.89 Å. Isotropic displacement parameters for H atoms were calculated as Uiso(H) = 1.2Ueq(C) for CH2 groups and Uiso(H) = 1.5Ueq(N1) for the ammonium group.
Hexavalent chromium is a predominant waste product of several metal finishing, petroleum refining and steel industries (Wani et al., 2007). It exists as chromate in basic and neutral medium and as dichromate in acidic environment.
In presence of 1,3-diaminopropane in water, the chromic acid is condensed into dichromate to form the hybrid title compound, (C3H12N2)Cr2O7. The observed molecular structure is depicted in Fig. 1. To counter-balance the electric charge of Cr2O72-, the used 1,3-diaminopropane has been doubly protonated. The title compound crystallizes in the orthorhombic Pnma space group, so that the dichromate anion and 1,3-diammoniumpropane should be symmetrical with respect to the symmetry plane (m). Owing of the passage of the latter through the bridging atoms O1 and C2 of Cr2O7 and C3H12N2 respectively, the asymmetric unit is built by one independent CrO4 group and the half of a 1,3-diammoniumpropane cation. The main geometrical features of Cr2O72- agree with those previously observed for this group in other compounds (Akriche & Rzaigui, 2009; Sieroń, 2007; Khadhrani et al., 2006).
The bond lengths and the angles within the cation are comparable with those observed in other 1,3-diammoniumpropane salts such as [C3H12N2]ZnCl4 (Kallel et al., 1980) and [C3H12N2](ClO4)2 (Pritchard et al., 1992). In this structure, the cations and anions are alternately stacked to form columns parallel to the axis b (Fig. 2). The electrostatic interactions and H-bonds intra and inter columns keep up the three-dimensional network cohesion. The established weak H-bonds (Brown, 1976; Blessing, 1986) of types N—H···O and C—H···O involve oxygen atoms of the dichromate anions as acceptors, and the protonated nitrogen atoms and carbon atoms of 1,3-diammoniumpropane as donors.
For related structures, see: Akriche & Rzaigui (2009); Sieroń (2007); Khadhrani et al. (2006); Kallel et al. (1980); Pritchard et al. (1992). For a discussion on hydrogen bonding, see: Brown (1976); Blessing (1986). For background on CrVI species as industrial waste, see: Wani et al. (2007).
Data collection: CAD-4 EXPRESS (Enraf–Nonius, 1994); cell refinement: CAD-4 EXPRESS (Enraf–Nonius, 1994); data reduction: XCAD4 (Harms & Wocadlo, 1995); program(s) used to solve structure: SIR92 (Altomare et al., 1994); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: ORTEP-3 (Farrugia, 1997) and DIAMOND (Brandenburg & Putz, 2005); software used to prepare material for publication: WinGX publication routines (Farrugia, 1999).
(C3H12N2)[Cr2O7] | F(000) = 592 |
Mr = 292.15 | Dx = 2.019 Mg m−3 |
Orthorhombic, Pnma | Ag Kα radiation, λ = 0.56083 Å |
Hall symbol: -P 2ac 2n | Cell parameters from 25 reflections |
a = 8.818 (2) Å | θ = 9–11° |
b = 13.764 (2) Å | µ = 1.18 mm−1 |
c = 7.918 (2) Å | T = 293 K |
V = 961.1 (4) Å3 | Prism, orange |
Z = 4 | 0.30 × 0.15 × 0.10 mm |
Enraf–Nonius CAD4 diffractometer | Rint = 0.020 |
Radiation source: fine-focus sealed tube | θmax = 28.0°, θmin = 2.3° |
Graphite monochromator | h = −14→3 |
non–profiled ω scans | k = −23→3 |
4877 measured reflections | l = −3→13 |
2430 independent reflections | 2 standard reflections every 120 min |
1811 reflections with I > 2σ(I) | intensity decay: 3% |
Refinement on F2 | Secondary atom site location: difference Fourier map |
Least-squares matrix: full | Hydrogen site location: inferred from neighbouring sites |
R[F2 > 2σ(F2)] = 0.032 | H-atom parameters constrained |
wR(F2) = 0.096 | w = 1/[σ2(Fo2) + (0.0502P)2 + 0.243P] where P = (Fo2 + 2Fc2)/3 |
S = 1.10 | (Δ/σ)max = 0.001 |
2430 reflections | Δρmax = 0.79 e Å−3 |
69 parameters | Δρmin = −0.61 e Å−3 |
0 restraints | Extinction correction: SHELXL97, Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4 |
0 constraints | Extinction coefficient: 0.024 (2) |
Primary atom site location: structure-invariant direct methods |
(C3H12N2)[Cr2O7] | V = 961.1 (4) Å3 |
Mr = 292.15 | Z = 4 |
Orthorhombic, Pnma | Ag Kα radiation, λ = 0.56083 Å |
a = 8.818 (2) Å | µ = 1.18 mm−1 |
b = 13.764 (2) Å | T = 293 K |
c = 7.918 (2) Å | 0.30 × 0.15 × 0.10 mm |
Enraf–Nonius CAD4 diffractometer | Rint = 0.020 |
4877 measured reflections | 2 standard reflections every 120 min |
2430 independent reflections | intensity decay: 3% |
1811 reflections with I > 2σ(I) |
R[F2 > 2σ(F2)] = 0.032 | 0 restraints |
wR(F2) = 0.096 | H-atom parameters constrained |
S = 1.10 | Δρmax = 0.79 e Å−3 |
2430 reflections | Δρmin = −0.61 e Å−3 |
69 parameters |
x | y | z | Uiso*/Ueq | ||
Cr | 0.58026 (3) | 0.131997 (16) | 0.65346 (3) | 0.01952 (8) | |
O2 | 0.59121 (13) | 0.05330 (8) | 0.80635 (15) | 0.0271 (2) | |
O4 | 0.72115 (14) | 0.11753 (9) | 0.52532 (16) | 0.0324 (3) | |
O3 | 0.42366 (14) | 0.11686 (10) | 0.55239 (19) | 0.0388 (3) | |
O1 | 0.5853 (2) | 0.2500 | 0.7434 (2) | 0.0322 (4) | |
N1 | 0.66136 (15) | 0.07105 (9) | 0.16706 (17) | 0.0263 (2) | |
H1A | 0.7277 | 0.0716 | 0.0824 | 0.039* | |
H1B | 0.6016 | 0.0192 | 0.1578 | 0.039* | |
H1C | 0.7109 | 0.0687 | 0.2649 | 0.039* | |
C2 | 0.6661 (2) | 0.2500 | 0.1633 (3) | 0.0237 (3) | |
H2A | 0.7327 | 0.2500 | 0.0658 | 0.028* | |
H2B | 0.7285 | 0.2500 | 0.2642 | 0.028* | |
C1 | 0.56785 (16) | 0.16037 (11) | 0.16067 (19) | 0.0231 (2) | |
H1D | 0.4995 | 0.1615 | 0.2567 | 0.028* | |
H1E | 0.5070 | 0.1601 | 0.0586 | 0.028* |
U11 | U22 | U33 | U12 | U13 | U23 | |
Cr | 0.02104 (11) | 0.01893 (11) | 0.01860 (11) | −0.00012 (7) | −0.00096 (8) | 0.00048 (7) |
O2 | 0.0335 (5) | 0.0232 (4) | 0.0245 (4) | −0.0013 (4) | −0.0003 (4) | 0.0043 (4) |
O4 | 0.0308 (6) | 0.0386 (6) | 0.0277 (5) | 0.0028 (4) | 0.0079 (5) | 0.0010 (5) |
O3 | 0.0285 (6) | 0.0481 (7) | 0.0398 (7) | −0.0008 (5) | −0.0122 (5) | −0.0022 (6) |
O1 | 0.0481 (10) | 0.0202 (6) | 0.0282 (7) | 0.000 | 0.0002 (7) | 0.000 |
N1 | 0.0279 (6) | 0.0220 (5) | 0.0289 (6) | 0.0000 (5) | 0.0022 (5) | 0.0018 (5) |
C2 | 0.0207 (8) | 0.0216 (7) | 0.0287 (9) | 0.000 | 0.0028 (7) | 0.000 |
C1 | 0.0206 (6) | 0.0235 (6) | 0.0252 (6) | −0.0010 (4) | −0.0002 (5) | −0.0005 (5) |
Cr—O3 | 1.6096 (13) | N1—H1C | 0.8900 |
Cr—O4 | 1.6165 (13) | C2—C1 | 1.5077 (19) |
Cr—O2 | 1.6274 (12) | C2—C1i | 1.5077 (19) |
Cr—O1 | 1.7740 (8) | C2—H2A | 0.9700 |
O1—Cri | 1.7740 (8) | C2—H2B | 0.9700 |
N1—C1 | 1.481 (2) | C1—H1D | 0.9700 |
N1—H1A | 0.8900 | C1—H1E | 0.9700 |
N1—H1B | 0.8900 | ||
O3—Cr—O4 | 109.35 (8) | C1—C2—C1i | 109.83 (17) |
O3—Cr—O2 | 109.55 (7) | C1—C2—H2A | 109.7 |
O4—Cr—O2 | 109.84 (6) | C1i—C2—H2A | 109.7 |
O3—Cr—O1 | 109.85 (8) | C1—C2—H2B | 109.7 |
O4—Cr—O1 | 110.21 (8) | C1i—C2—H2B | 109.7 |
O2—Cr—O1 | 108.02 (7) | H2A—C2—H2B | 108.2 |
Cr—O1—Cri | 132.57 (11) | N1—C1—C2 | 111.03 (13) |
C1—N1—H1A | 109.5 | N1—C1—H1D | 109.4 |
C1—N1—H1B | 109.5 | C2—C1—H1D | 109.4 |
H1A—N1—H1B | 109.5 | N1—C1—H1E | 109.4 |
C1—N1—H1C | 109.5 | C2—C1—H1E | 109.4 |
H1A—N1—H1C | 109.5 | H1D—C1—H1E | 108.0 |
H1B—N1—H1C | 109.5 |
Symmetry code: (i) x, −y+1/2, z. |
D—H···A | D—H | H···A | D···A | D—H···A |
N1—H1A···O2ii | 0.89 | 2.51 | 2.9326 (19) | 110 |
N1—H1A···O3iii | 0.89 | 2.12 | 2.9609 (19) | 156 |
N1—H1B···O2iv | 0.89 | 1.99 | 2.8168 (19) | 154 |
N1—H1C···O4 | 0.89 | 2.17 | 2.955 (2) | 147 |
N1—H1C···O2v | 0.89 | 2.44 | 2.9844 (19) | 120 |
C1—H1D···O3 | 0.97 | 2.51 | 3.405 (2) | 153 |
C1—H1E···O2ii | 0.97 | 2.59 | 3.176 (2) | 119 |
Symmetry codes: (ii) x, y, z−1; (iii) x+1/2, y, −z+1/2; (iv) −x+1, −y, −z+1; (v) −x+3/2, −y, z−1/2. |
Experimental details
Crystal data | |
Chemical formula | (C3H12N2)[Cr2O7] |
Mr | 292.15 |
Crystal system, space group | Orthorhombic, Pnma |
Temperature (K) | 293 |
a, b, c (Å) | 8.818 (2), 13.764 (2), 7.918 (2) |
V (Å3) | 961.1 (4) |
Z | 4 |
Radiation type | Ag Kα, λ = 0.56083 Å |
µ (mm−1) | 1.18 |
Crystal size (mm) | 0.30 × 0.15 × 0.10 |
Data collection | |
Diffractometer | Enraf–Nonius CAD4 |
Absorption correction | – |
No. of measured, independent and observed [I > 2σ(I)] reflections | 4877, 2430, 1811 |
Rint | 0.020 |
(sin θ/λ)max (Å−1) | 0.836 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.032, 0.096, 1.10 |
No. of reflections | 2430 |
No. of parameters | 69 |
H-atom treatment | H-atom parameters constrained |
Δρmax, Δρmin (e Å−3) | 0.79, −0.61 |
Computer programs: CAD-4 EXPRESS (Enraf–Nonius, 1994), XCAD4 (Harms & Wocadlo, 1995), SIR92 (Altomare et al., 1994), SHELXL97 (Sheldrick, 2008), ORTEP-3 (Farrugia, 1997) and DIAMOND (Brandenburg & Putz, 2005), WinGX publication routines (Farrugia, 1999).
D—H···A | D—H | H···A | D···A | D—H···A |
N1—H1A···O3i | 0.89 | 2.12 | 2.9609 (19) | 156.3 |
N1—H1B···O2ii | 0.89 | 1.99 | 2.8168 (19) | 153.5 |
N1—H1C···O4 | 0.89 | 2.17 | 2.955 (2) | 146.7 |
N1—H1C···O2iii | 0.89 | 2.44 | 2.9844 (19) | 119.5 |
C1—H1D···O3 | 0.97 | 2.51 | 3.405 (2) | 153.1 |
C1—H1E···O2iv | 0.97 | 2.59 | 3.176 (2) | 119.1 |
Symmetry codes: (i) x+1/2, y, −z+1/2; (ii) −x+1, −y, −z+1; (iii) −x+3/2, −y, z−1/2; (iv) x, y, z−1. |
Hexavalent chromium is a predominant waste product of several metal finishing, petroleum refining and steel industries (Wani et al., 2007). It exists as chromate in basic and neutral medium and as dichromate in acidic environment.
In presence of 1,3-diaminopropane in water, the chromic acid is condensed into dichromate to form the hybrid title compound, (C3H12N2)Cr2O7. The observed molecular structure is depicted in Fig. 1. To counter-balance the electric charge of Cr2O72-, the used 1,3-diaminopropane has been doubly protonated. The title compound crystallizes in the orthorhombic Pnma space group, so that the dichromate anion and 1,3-diammoniumpropane should be symmetrical with respect to the symmetry plane (m). Owing of the passage of the latter through the bridging atoms O1 and C2 of Cr2O7 and C3H12N2 respectively, the asymmetric unit is built by one independent CrO4 group and the half of a 1,3-diammoniumpropane cation. The main geometrical features of Cr2O72- agree with those previously observed for this group in other compounds (Akriche & Rzaigui, 2009; Sieroń, 2007; Khadhrani et al., 2006).
The bond lengths and the angles within the cation are comparable with those observed in other 1,3-diammoniumpropane salts such as [C3H12N2]ZnCl4 (Kallel et al., 1980) and [C3H12N2](ClO4)2 (Pritchard et al., 1992). In this structure, the cations and anions are alternately stacked to form columns parallel to the axis b (Fig. 2). The electrostatic interactions and H-bonds intra and inter columns keep up the three-dimensional network cohesion. The established weak H-bonds (Brown, 1976; Blessing, 1986) of types N—H···O and C—H···O involve oxygen atoms of the dichromate anions as acceptors, and the protonated nitrogen atoms and carbon atoms of 1,3-diammoniumpropane as donors.