The structure of the title complex, (C4H12N2)[Cr2O7], consists of dichromate dianions which are connected to the cyclic organic piperazinium (pipH2)2+ dications via hydrogen bonding. There are two crystallographically independent piperazinium dications, both located on centres of inversion, while the anions are located in general positions.
Supporting information
CCDC reference: 252754
Key indicators
- Single-crystal X-ray study
- T = 293 K
- Mean (C-C) = 0.003 Å
- R factor = 0.026
- wR factor = 0.078
- Data-to-parameter ratio = 21.2
checkCIF/PLATON results
No syntax errors found
Alert level C
PLAT042_ALERT_1_C Calc. and Rep. MoietyFormula Strings Differ .... ?
PLAT125_ALERT_4_C No _symmetry_space_group_name_Hall Given ....... ?
PLAT232_ALERT_2_C Hirshfeld Test Diff (M-X) Cr2 - O7 .. 5.41 su
PLAT720_ALERT_4_C Number of Unusual/Non-Standard Label(s) ........ 4
PLAT764_ALERT_4_C Overcomplete CIF Bond List Detected (Rep/Expd) . 1.14 Ratio
0 ALERT level A = In general: serious problem
0 ALERT level B = Potentially serious problem
5 ALERT level C = Check and explain
0 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
0 ALERT type 3 Indicator that the structure quality may be low
3 ALERT type 4 Improvement, methodology, query or suggestion
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 dichromate(VI)
top
Crystal data top
(C4H12N2)[Cr2O7] | F(000) = 616 |
Mr = 304.16 | Dx = 2.033 Mg m−3 |
Monoclinic, P21/c | Mo Kα radiation, λ = 0.71073 Å |
a = 11.654 (2) Å | Cell parameters from 86 reflections |
b = 7.8702 (6) Å | θ = 26–38° |
c = 10.855 (2) Å | µ = 2.21 mm−1 |
β = 93.42 (1)° | T = 293 K |
V = 993.8 (3) Å3 | Block, orange |
Z = 4 | 0.13 × 0.11 × 0.07 mm |
Data collection top
Stoe AED-II four-circle diffractometer | 2459 reflections with I > 2σ(I) |
Radiation source: fine-focus sealed tube | Rint = 0.033 |
Graphite monochromator | θmax = 30.0°, θmin = 1.8° |
ω–θ scans | h = −16→16 |
Absorption correction: numerical (X-SHAPE; Stoe & Cie, 1998) | k = −2→11 |
Tmin = 0.755, Tmax = 0.860 | l = −15→0 |
3793 measured reflections | 4 standard reflections every 120 min |
2901 independent reflections | intensity decay: none |
Refinement top
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)] = 0.026 | H-atom parameters constrained |
wR(F2) = 0.078 | w = 1/[σ2(Fo2) + (0.044P)2 + 0.3618P] where P = (Fo2 + 2Fc2)/3 |
S = 1.07 | (Δ/σ)max = 0.001 |
2901 reflections | Δρmax = 0.51 e Å−3 |
137 parameters | Δρmin = −0.62 e Å−3 |
0 restraints | Extinction correction: SHELXL97, Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4 |
Primary atom site location: structure-invariant direct methods | Extinction coefficient: 0.0126 (13) |
Special details top
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) top | x | y | z | Uiso*/Ueq | |
Cr1 | 0.76786 (2) | 0.49764 (3) | 0.69306 (2) | 0.01776 (9) | |
Cr2 | 0.72684 (2) | 0.57837 (4) | 0.41834 (2) | 0.01897 (9) | |
O1 | 0.77675 (14) | 0.33146 (19) | 0.77908 (13) | 0.0319 (3) | |
O2 | 0.88590 (12) | 0.60764 (19) | 0.71735 (13) | 0.0277 (3) | |
O3 | 0.65597 (13) | 0.6068 (2) | 0.72271 (13) | 0.0305 (3) | |
O4 | 0.75442 (12) | 0.42432 (17) | 0.53686 (12) | 0.0246 (3) | |
O5 | 0.81900 (19) | 0.5539 (2) | 0.31704 (17) | 0.0483 (5) | |
O6 | 0.59705 (15) | 0.5528 (2) | 0.35954 (15) | 0.0374 (4) | |
O7 | 0.73990 (12) | 0.76513 (17) | 0.48130 (12) | 0.0262 (3) | |
N1 | 0.96670 (13) | 0.9161 (2) | 0.60951 (13) | 0.0215 (3) | |
H1N1 | 0.9185 | 0.8479 | 0.6483 | 0.026* | |
H2N1 | 1.0224 | 0.9498 | 0.6651 | 0.026* | |
C1 | 1.01935 (15) | 0.8183 (2) | 0.50881 (17) | 0.0231 (3) | |
H1A | 0.9592 | 0.7734 | 0.4524 | 0.028* | |
H1B | 1.0631 | 0.7234 | 0.5441 | 0.028* | |
C2 | 0.90256 (15) | 1.0674 (2) | 0.56055 (17) | 0.0224 (3) | |
H2A | 0.8720 | 1.1299 | 0.6283 | 0.027* | |
H2B | 0.8385 | 1.0310 | 0.5058 | 0.027* | |
N2 | 0.56364 (15) | 0.5708 (2) | 0.10427 (15) | 0.0264 (3) | |
H1N2 | 0.6237 | 0.6182 | 0.0687 | 0.032* | |
H2N2 | 0.5725 | 0.5898 | 0.1860 | 0.032* | |
C3 | 0.56324 (17) | 0.3850 (2) | 0.08107 (18) | 0.0278 (4) | |
H3A | 0.5026 | 0.3323 | 0.1251 | 0.033* | |
H3B | 0.6360 | 0.3368 | 0.1120 | 0.033* | |
C4 | 0.45517 (17) | 0.6525 (2) | 0.05457 (19) | 0.0288 (4) | |
H4A | 0.4596 | 0.7743 | 0.0674 | 0.035* | |
H4B | 0.3908 | 0.6094 | 0.0979 | 0.035* | |
Atomic displacement parameters (Å2) top | U11 | U22 | U33 | U12 | U13 | U23 |
Cr1 | 0.02122 (14) | 0.01581 (14) | 0.01630 (13) | 0.00043 (10) | 0.00146 (9) | 0.00036 (9) |
Cr2 | 0.02653 (15) | 0.01550 (13) | 0.01526 (13) | −0.00336 (10) | 0.00430 (9) | −0.00083 (10) |
O1 | 0.0462 (8) | 0.0231 (7) | 0.0266 (6) | 0.0006 (6) | 0.0026 (6) | 0.0075 (6) |
O2 | 0.0267 (6) | 0.0279 (7) | 0.0283 (6) | −0.0062 (5) | −0.0016 (5) | 0.0010 (5) |
O3 | 0.0306 (7) | 0.0324 (8) | 0.0291 (6) | 0.0082 (6) | 0.0062 (5) | −0.0027 (6) |
O4 | 0.0364 (7) | 0.0180 (6) | 0.0192 (5) | 0.0026 (5) | −0.0005 (5) | −0.0014 (5) |
O5 | 0.0747 (13) | 0.0284 (8) | 0.0462 (9) | 0.0001 (8) | 0.0410 (9) | −0.0011 (7) |
O6 | 0.0428 (9) | 0.0305 (8) | 0.0366 (8) | −0.0120 (7) | −0.0157 (7) | 0.0072 (6) |
O7 | 0.0303 (7) | 0.0194 (6) | 0.0290 (6) | −0.0030 (5) | 0.0030 (5) | −0.0039 (5) |
N1 | 0.0230 (7) | 0.0227 (7) | 0.0192 (6) | −0.0044 (6) | 0.0049 (5) | 0.0028 (5) |
C1 | 0.0247 (8) | 0.0177 (8) | 0.0272 (8) | −0.0019 (6) | 0.0053 (6) | −0.0007 (6) |
C2 | 0.0197 (7) | 0.0218 (8) | 0.0265 (8) | 0.0002 (6) | 0.0069 (6) | −0.0020 (7) |
N2 | 0.0303 (8) | 0.0249 (8) | 0.0238 (7) | −0.0050 (6) | 0.0000 (6) | −0.0037 (6) |
C3 | 0.0290 (9) | 0.0217 (8) | 0.0327 (9) | 0.0019 (7) | 0.0004 (7) | 0.0067 (7) |
C4 | 0.0309 (9) | 0.0205 (8) | 0.0358 (9) | 0.0039 (7) | 0.0096 (7) | −0.0052 (8) |
Geometric parameters (Å, º) top
Cr1—O1 | 1.6068 (14) | C1—H1B | 0.9700 |
Cr1—O3 | 1.6101 (14) | C2—C1i | 1.512 (2) |
Cr1—O2 | 1.6334 (14) | C2—H2A | 0.9700 |
Cr1—O4 | 1.7890 (13) | C2—H2B | 0.9700 |
Cr2—O5 | 1.5939 (16) | N2—C3 | 1.484 (3) |
Cr2—O6 | 1.6189 (16) | N2—C4 | 1.490 (3) |
Cr2—O7 | 1.6242 (14) | N2—H1N2 | 0.9000 |
Cr2—O4 | 1.7830 (13) | N2—H2N2 | 0.9000 |
N1—C2 | 1.487 (2) | C3—C4ii | 1.504 (3) |
N1—C1 | 1.498 (2) | C3—H3A | 0.9700 |
N1—H1N1 | 0.9000 | C3—H3B | 0.9700 |
N1—H2N1 | 0.9000 | C4—C3ii | 1.504 (3) |
C1—C2i | 1.512 (2) | C4—H4A | 0.9700 |
C1—H1A | 0.9700 | C4—H4B | 0.9700 |
| | | |
O1—Cr1—O3 | 110.06 (8) | N1—C2—C1i | 110.47 (14) |
O1—Cr1—O2 | 108.25 (8) | N1—C2—H2A | 109.6 |
O3—Cr1—O2 | 111.67 (8) | C1i—C2—H2A | 109.6 |
O1—Cr1—O4 | 106.69 (7) | N1—C2—H2B | 109.6 |
O3—Cr1—O4 | 109.60 (7) | C1i—C2—H2B | 109.6 |
O2—Cr1—O4 | 110.44 (7) | H2A—C2—H2B | 108.1 |
O5—Cr2—O6 | 111.42 (11) | C3—N2—C4 | 111.69 (15) |
O5—Cr2—O7 | 110.45 (8) | C3—N2—H1N2 | 109.3 |
O6—Cr2—O7 | 109.88 (8) | C4—N2—H1N2 | 109.3 |
O5—Cr2—O4 | 108.41 (9) | C3—N2—H2N2 | 109.3 |
O6—Cr2—O4 | 108.91 (7) | C4—N2—H2N2 | 109.3 |
O7—Cr2—O4 | 107.67 (7) | H1N2—N2—H2N2 | 107.9 |
Cr2—O4—Cr1 | 117.79 (7) | N2—C3—C4ii | 110.97 (15) |
C2—N1—C1 | 111.69 (13) | N2—C3—H3A | 109.4 |
C2—N1—H1N1 | 109.3 | C4ii—C3—H3A | 109.4 |
C1—N1—H1N1 | 109.3 | N2—C3—H3B | 109.4 |
C2—N1—H2N1 | 109.3 | C4ii—C3—H3B | 109.4 |
C1—N1—H2N1 | 109.3 | H3A—C3—H3B | 108.0 |
H1N1—N1—H2N1 | 107.9 | N2—C4—C3ii | 109.77 (15) |
N1—C1—C2i | 110.06 (14) | N2—C4—H4A | 109.7 |
N1—C1—H1A | 109.6 | C3ii—C4—H4A | 109.7 |
C2i—C1—H1A | 109.6 | N2—C4—H4B | 109.7 |
N1—C1—H1B | 109.6 | C3ii—C4—H4B | 109.7 |
C2i—C1—H1B | 109.6 | H4A—C4—H4B | 108.2 |
H1A—C1—H1B | 108.2 | | |
Symmetry codes: (i) −x+2, −y+2, −z+1; (ii) −x+1, −y+1, −z. |
Hydrogen-bond geometry (Å, º) top
D—H···A | D—H | H···A | D···A | D—H···A |
N1—H1N1···O2 | 0.90 | 2.08 | 2.878 (2) | 148 |
N1—H1N1···O5iii | 0.90 | 2.36 | 2.925 (2) | 121 |
N1—H2N1···O2iv | 0.90 | 2.04 | 2.893 (2) | 159 |
N1—H2N1···O1iv | 0.90 | 2.56 | 3.227 (2) | 132 |
N2—H1N2···O7v | 0.90 | 1.93 | 2.828 (2) | 174 |
N2—H2N2···O6 | 0.90 | 1.91 | 2.779 (2) | 162 |
Symmetry codes: (iii) x, −y+3/2, z+1/2; (iv) −x+2, y+1/2, −z+3/2; (v) x, −y+3/2, z−1/2. |