Chromate d'éthylènediammonium

A new organic chromate, ethylenediammonium chromate, [NH₃(CH₂)₂NH₃][CrO₄], has been isolated. Its structure is built up from organic cations and chromate anions, which pack in columns parallel to the a axis. The cohesion and stability of the ionic arragement result from a three-dimensional network of N—H...O hydrogen bonds.

Key indicators

• Single-crystal X-ray study
• T = 293 K
• Mean [sigma](C-C) = 0.004 Å
• R factor = 0.023
• wR factor = 0.067
• Data-to-parameter ratio = 10.3

checkCIF/PLATON results

No syntax errors found



Alert level A
PLAT052_ALERT_1_A (Proper) Absorption Correction Method Missing ..          ?

Alert level B
PLAT057_ALERT_3_B Correction for Absorption Required   RT(exp) ...       1.30

Alert level C
PLAT034_ALERT_1_C No Flack Parameter Given. Z .GT. Si, NonCentro .          ?
PLAT790_ALERT_4_C Centre of Gravity not Within Unit Cell: Resd.  #          1
              C2 H10 N2

Alert level G
REFLT03_ALERT_4_G  WARNING: Large fraction of Friedel related reflns may
                     be needed to determine absolute structure
           From the CIF: _diffrn_reflns_theta_max           27.96
           From the CIF: _reflns_number_total               1141
           Count of symmetry unique reflns         1010
           Completeness (_total/calc)            112.97%
           TEST3: Check Friedels for noncentro structure
           Estimate of Friedel pairs measured       131
           Fraction of Friedel pairs measured     0.130
           Are heavy atom types Z>Si present          yes

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

   2 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
   1 ALERT type 3 Indicator that the structure quality may be low
   2 ALERT type 4 Improvement, methodology, query or suggestion

---

Computing details

Data collection: CAD-4 EXPRESS (Duisenberg, 1992; Macíček & Yordanov, 1992); cell refinement: CAD-4 EXPRESS; data reduction: XCAD4 (Harms & Wocadlo, 1995); program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: ORTEPIII (Johnson & Burnett, 1997) et DIAMOND (Brandenburg, 1998); software used to prepare material for publication: SHELXL97.

ethylenediammonium chromate

Crystal data

(C2H10N2)[CrO4]	F(000) = 368
Mr = 178.12	Dx = 1.676 Mg m^−3
Orthorhombic, P212121	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: P 2ac 2ab	Cell parameters from 25 reflections
a = 6.6778 (13) Å	θ = 10.2–15.1°
b = 8.9040 (17) Å	µ = 1.57 mm^−1
c = 11.876 (2) Å	T = 293 K
V = 706.1 (2) Å^3	Prism, yellow
Z = 4	0.35 × 0.27 × 0.15 mm

Data collection

Enraf-Nonius CAD-4 diffractometer	1076 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tube	Rint = 0.046
Graphite monochromator	θmax = 28.0°, θmin = 2.9°
ω/2θ scans	h = −1→8
Absorption correction: ψ scan (North et al., 1968)	k = 0→11
Tmin = 0.607, Tmax = 0.790	l = 0→15
1167 measured reflections	2 standard reflections every 120 min
1141 independent reflections	intensity decay: 1.0%

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)] = 0.023	H atoms treated by a mixture of independent and constrained refinement
wR(F^2) = 0.067	w = 1/[σ^2(Fo^2) + (0.0364P)^2 + 0.1776P] where P = (Fo^2 + 2Fc^2)/3
S = 1.13	(Δ/σ)max = 0.001
1141 reflections	Δρmax = 0.29 e Å^−3
111 parameters	Δρmin = −0.28 e Å^−3
2 restraints	Extinction correction: SHELXL97 (Sheldrick, 1997), Fc^*=kFc[1+0.001xFc^2λ^3/sin(2θ)]^-1/4
Primary atom site location: structure-invariant direct methods	Extinction coefficient: 0.034 (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
Cr	0.17097 (6)	0.48771 (4)	0.60978 (3)	0.02252 (14)
O1	−0.0566 (3)	0.5515 (3)	0.6077 (2)	0.0413 (5)
O2	0.3272 (3)	0.63750 (18)	0.60783 (15)	0.0269 (4)
O3	0.2139 (3)	0.3897 (2)	0.72717 (15)	0.0337 (5)
O4	0.2161 (4)	0.3827 (2)	0.49964 (16)	0.0381 (5)
N1	−0.0498 (4)	0.3830 (3)	0.9090 (2)	0.0262 (5)
N2	−0.4612 (4)	0.6425 (3)	0.8120 (2)	0.0297 (5)
C1	−0.3386 (4)	0.5036 (3)	0.8198 (2)	0.0286 (5)
H11	−0.2858	0.4786	0.7461	0.046 (10)*
H12	−0.4221	0.4208	0.8447	0.032 (9)*
C2	−0.1668 (4)	0.5251 (3)	0.9020 (2)	0.0272 (5)
H21	−0.0811	0.6062	0.8766	0.038 (9)*
H22	−0.2188	0.5512	0.9757	0.039 (9)*
H1A	0.028 (6)	0.377 (4)	0.966 (3)	0.036 (9)*
H1B	−0.132 (6)	0.305 (4)	0.911 (3)	0.035 (9)*
H1C	0.041 (5)	0.371 (4)	0.851 (3)	0.034 (9)*
H2A	−0.378 (4)	0.714 (3)	0.809 (3)	0.030 (8)*
H2B	−0.526 (6)	0.649 (4)	0.880 (3)	0.044 (10)*
H2C	−0.533 (8)	0.637 (6)	0.750 (3)	0.089 (17)*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Cr	0.0236 (2)	0.02180 (18)	0.02219 (19)	−0.00060 (15)	0.00038 (16)	0.00056 (15)
O1	0.0248 (10)	0.0463 (11)	0.0529 (12)	0.0033 (9)	−0.0011 (10)	0.0029 (12)
O2	0.0281 (9)	0.0235 (7)	0.0293 (8)	−0.0018 (7)	0.0002 (10)	0.0012 (7)
O3	0.0428 (12)	0.0315 (9)	0.0266 (9)	0.0045 (10)	0.0041 (9)	0.0065 (7)
O4	0.0491 (13)	0.0357 (10)	0.0294 (9)	−0.0023 (11)	−0.0001 (10)	−0.0086 (8)
N1	0.0265 (11)	0.0243 (10)	0.0279 (11)	−0.0013 (9)	−0.0022 (10)	0.0002 (9)
N2	0.0284 (12)	0.0267 (11)	0.0340 (12)	−0.0026 (10)	−0.0054 (11)	0.0022 (10)
C1	0.0296 (12)	0.0266 (11)	0.0295 (11)	−0.0041 (16)	−0.0017 (11)	−0.0019 (10)
C2	0.0278 (12)	0.0245 (10)	0.0293 (11)	0.0033 (13)	−0.0036 (12)	−0.0017 (10)

Geometric parameters (Å, º)

Cr—O1	1.623 (2)	N2—H2A	0.85 (3)
Cr—O4	1.636 (2)	N2—H2B	0.92 (4)
Cr—O3	1.670 (2)	N2—H2C	0.88 (2)
Cr—O2	1.693 (2)	C1—C2	1.518 (4)
N1—C2	1.489 (3)	C1—H11	0.9700
N1—H1A	0.85 (4)	C1—H12	0.9700
N1—H1B	0.88 (4)	C2—H21	0.9700
N1—H1C	0.92 (4)	C2—H22	0.9700
N2—C1	1.486 (3)
O1—Cr—O4	111.1 (1)	C1—N2—H2C	108 (4)
O1—Cr—O3	110.9 (1)	H2A—N2—H2C	111 (4)
O4—Cr—O3	109.7 (1)	H2B—N2—H2C	119 (4)
O1—Cr—O2	107.5 (1)	N2—C1—C2	110.6 (2)
O4—Cr—O2	109.0 (1)	N2—C1—H11	109.5
O3—Cr—O2	108.5 (1)	C2—C1—H11	109.5
C2—N1—H1A	115 (2)	N2—C1—H12	109.5
C2—N1—H1B	110 (2)	C2—C1—H12	109.5
H1A—N1—H1B	108 (3)	H11—C1—H12	108.1
C2—N1—H1C	114 (2)	N1—C2—C1	109.0 (2)
H1A—N1—H1C	100 (3)	N1—C2—H21	109.9
H1B—N1—H1C	110 (3)	C1—C2—H21	109.9
C1—N2—H2A	105 (2)	N1—C2—H22	109.9
C1—N2—H2B	105 (2)	C1—C2—H22	109.9
H2A—N2—H2B	107 (3)	H21—C2—H22	108.3

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
N1—H1A···O2^i	0.86 (4)	1.95 (4)	2.796 (3)	171 (4)
N2—H2A···O3^ii	0.85 (3)	1.95 (3)	2.789 (3)	170 (4)
N1—H1B···O1^iii	0.89 (4)	2.57 (4)	3.046 (4)	112 (3)
N1—H1B···O2^iii	0.89 (4)	1.99 (4)	2.873 (3)	170 (4)
N2—H2B···O4^iv	0.92 (4)	1.91 (4)	2.813 (3)	165 (3)
N1—H1C···O3	0.92 (3)	1.88 (3)	2.787 (3)	167 (3)
N2—H2C···O2^v	0.92 (3)	1.93 (4)	2.807 (3)	175 (3)

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