p-Phenyl­enediammonium tetra­bromo­aurate(III) bromide monohydrate

The structure of the title compound, (C₆H₁₀N₂)[AuBr₄]Br·H₂O, consists of twin parallel stacks of square-planar [AuBr₄^-] polyhedra ordered along the a axis. The stacks are inter­leaved such that one Br atom of the AuBr₄^- square planes of one twin stack lies directly above or behind the Au atom from the neighboring stack, creating a pseudo-Jahn-Teller-like distorted octa­hedral coordination environment around the Au^III ions. The twin stacks are separated by parallel stacks of p-phenyl­enediammonium cations, and the structure is presumably held together by coulombic forces between the inter­digitated negatively and positively charged one-dimensional stacks. The water mol­ecule, the tetra­bromo­aurate anion and the bromide anion all lie on mirror planes.

Key indicators

• Single-crystal X-ray study
• T = 293 K
• Mean [sigma](C-C) = 0.020 Å
• R factor = 0.082
• wR factor = 0.211
• Data-to-parameter ratio = 22.9

checkCIF/PLATON results

No syntax errors found



Alert level C
DIFMX01_ALERT_2_C  The maximum difference density is > 0.1*ZMAX*0.75
            _refine_diff_density_max given =      7.132
            Test value =      5.925
DIFMX02_ALERT_1_C  The maximum difference density is > 0.1*ZMAX*0.75
            The relevant atom site should be identified.
RINTA01_ALERT_3_C  The value of Rint is greater than 0.10
            Rint given   0.100
PLAT029_ALERT_3_C _diffrn_measured_fraction_theta_full Low .......       0.96
PLAT042_ALERT_1_C Calc. and Rep. MoietyFormula Strings Differ ....          ?
PLAT062_ALERT_4_C Rescale T(min) & T(max) by .....................       0.73
PLAT097_ALERT_2_C Maximum (Positive) Residual Density ............       7.13 e/A   
PLAT125_ALERT_4_C No _symmetry_space_group_name_Hall Given .......          ?
PLAT342_ALERT_3_C Low Bond Precision on C-C bonds (x 1000) Ang ...         20
PLAT431_ALERT_2_C Short Inter HL..A Contact  Br1    ..  Br3     ..       3.59 Ang.
PLAT431_ALERT_2_C Short Inter HL..A Contact  Br1    ..  Br3     ..       3.59 Ang.
PLAT764_ALERT_4_C Overcomplete CIF Bond List Detected (Rep/Expd) .       1.12 Ratio
PLAT790_ALERT_4_C Centre of Gravity not Within Unit Cell: Resd.  #          3
              H2 O
PLAT790_ALERT_4_C Centre of Gravity not Within Unit Cell: Resd.  #          4
              Br

Alert level G
ABSTM02_ALERT_3_G  When printed, the submitted absorption T values will be
            replaced by the scaled T values. Since the ratio of scaled T's
            is identical to the ratio of reported T values, the scaling
            does not imply a change to the absorption corrections used in
            the study.
            Ratio of Tmax expected/reported      0.731
            Tmax scaled      0.317 Tmin scaled      0.083
REFLT03_ALERT_1_G ALERT: Expected hkl max differ from CIF values
           From the CIF: _diffrn_reflns_theta_max           27.48
           From the CIF: _reflns_number_total               1741
           From the CIF: _diffrn_reflns_limit_ max hkl    8.   14.   22.
           From the CIF: _diffrn_reflns_limit_ min hkl   -6.  -14.  -20.
           TEST1: Expected hkl limits for theta max
           Calculated maximum hkl    8.   14.   25.
           Calculated minimum hkl   -8.  -14.  -25.
PLAT199_ALERT_1_G Check the Reported _cell_measurement_temperature        293 K
PLAT200_ALERT_1_G Check the Reported _diffrn_ambient_temperature .        293 K

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

   5 ALERT type 1 CIF construction/syntax error, inconsistent or missing data
   4 ALERT type 2 Indicator that the structure model may be wrong or deficient
   4 ALERT type 3 Indicator that the structure quality may be low
   5 ALERT type 4 Improvement, methodology, query or suggestion
   0 ALERT type 5 Informative message, check

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Computing details

Data collection: COLLECT (Nonius, 2000); cell refinement: SCALEPACK (Otwinowski & Minor, 1997); data reduction: SCALEPACK and DENZO (Otwinowski & Minor, 1997); program(s) used to solve structure: SIR92 (Altomare et al., 1993); program(s) used to refine structure: SHELXTL (Bruker, 2000); molecular graphics: SHELXTL (Bruker, 2000) and MaterialsStudio (Accelrys, 2002).

p-Phenylenediammonium tetrabromoaurate(III) bromide monohydrate

Crystal data

(C6H10N2)[AuBr4]Br·H2O	Dx = 3.191 Mg m^−3
Mr = 724.69	Mo Kα radiation, λ = 0.71073 Å
Orthorhombic, Pnma	Cell parameters from 3791 reflections
a = 6.8462 (3) Å	θ = 1.0–27.5°
b = 11.4379 (7) Å	µ = 22.97 mm^−1
c = 19.2654 (7) Å	T = 293 K
V = 1508.60 (13) Å^3	Needle, red
Z = 4	0.22 × 0.05 × 0.05 mm
F(000) = 1296

Data collection

Nonius KappaCCD diffractometer	1741 independent reflections
Radiation source: fine-focus sealed tube	1062 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.100
φ scans	θmax = 27.5°, θmin = 4.4°
Absorption correction: multi-scan (SORTAV; Blessing, 1995)	h = −6→8
Tmin = 0.113, Tmax = 0.434	k = −14→14
7709 measured reflections	l = −20→22

Refinement

Refinement on F^2	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F^2 > 2σ(F^2)] = 0.082	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.211	H-atom parameters constrained
S = 1.00	w = 1/[σ^2(Fo^2) + (0.1306P)^2] where P = (Fo^2 + 2Fc^2)/3
1739 reflections	(Δ/σ)max < 0.001
76 parameters	Δρmax = 7.13 e Å^−3
0 restraints	Δρmin = −4.83 e Å^−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
Au1	0.59816 (11)	0.2500	0.18595 (4)	0.0353 (4)
Br1	0.5761 (3)	0.2500	−0.13749 (13)	0.0490 (7)
Br2	0.5908 (3)	0.2500	0.31329 (10)	0.0395 (6)
Br3	0.5856 (2)	0.03734 (17)	0.18516 (7)	0.0443 (5)
Br4	0.6163 (4)	0.2500	0.06017 (12)	0.0520 (7)
O1	0.126 (2)	0.2500	−0.1929 (8)	0.053 (5)
H1S	0.2473	0.2500	−0.1800	0.064*
H2S	0.1255	0.2500	−0.2374	0.064*
N1	0.0786 (17)	−0.0474 (13)	0.1410 (6)	0.046 (3)
H1A	0.0726	−0.1230	0.1410	0.055*
H1B	0.1990	−0.0584	0.1550	0.055*
H1C	0.0393	−0.0031	0.1740	0.055*
C1	0.035 (2)	−0.0223 (14)	0.0675 (7)	0.035 (4)
C2	0.163 (2)	0.0474 (17)	0.0316 (7)	0.042 (4)
H2	0.2720	0.0788	0.0534	0.050*
C3	0.127 (2)	0.0695 (16)	−0.0367 (8)	0.044 (4)
H3	0.2118	0.1164	−0.0621	0.053*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Au1	0.0238 (5)	0.0438 (6)	0.0383 (6)	0.000	0.0009 (3)	0.000
Br1	0.0348 (13)	0.0527 (16)	0.0594 (14)	0.000	−0.0006 (10)	0.000
Br2	0.0310 (12)	0.0506 (16)	0.0371 (13)	0.000	−0.0014 (9)	0.000
Br3	0.0404 (10)	0.0438 (11)	0.0486 (10)	0.0006 (7)	0.0026 (7)	−0.0010 (7)
Br4	0.0520 (15)	0.0639 (18)	0.0401 (13)	0.000	0.0017 (11)	0.000
O1	0.041 (10)	0.066 (14)	0.053 (10)	0.000	0.007 (7)	0.000
N1	0.039 (8)	0.065 (10)	0.033 (7)	0.009 (7)	−0.010 (5)	0.001 (7)
C1	0.028 (7)	0.043 (10)	0.036 (8)	−0.002 (7)	0.001 (6)	0.000 (7)
C2	0.030 (8)	0.071 (13)	0.025 (8)	0.000 (8)	−0.006 (6)	0.002 (7)
C3	0.038 (9)	0.045 (11)	0.049 (9)	−0.011 (8)	0.008 (7)	−0.003 (8)

Geometric parameters (Å, º)

Au1—Br4	2.427 (2)	N1—H1B	0.8761
Au1—Br3	2.434 (2)	N1—H1C	0.8567
Au1—Br3^i	2.4339 (19)	C1—C3^ii	1.37 (2)
Au1—Br2	2.454 (2)	C1—C2	1.37 (2)
O1—H1S	0.8671	C2—C3	1.36 (2)
O1—H2S	0.8571	C2—H2	0.9300
N1—C1	1.475 (18)	C3—C1^ii	1.37 (2)
N1—H1A	0.8657	C3—H3	0.9300
Br4—Au1—Br3	89.74 (4)	H1A—N1—H1C	125.2
Br4—Au1—Br3^i	89.74 (4)	H1B—N1—H1C	98.8
Br3—Au1—Br3^i	175.89 (8)	C3^ii—C1—C2	121.8 (13)
Br4—Au1—Br2	178.24 (8)	C3^ii—C1—N1	120.3 (14)
Br3—Au1—Br2	90.32 (4)	C2—C1—N1	117.8 (13)
Br3^i—Au1—Br2	90.32 (4)	C3—C2—C1	118.7 (15)
H1S—O1—H2S	106.9	C3—C2—H2	120.7
C1—N1—H1A	100.6	C1—C2—H2	120.7
C1—N1—H1B	121.0	C2—C3—C1^ii	119.5 (15)
H1A—N1—H1B	84.3	C2—C3—H3	120.3
C1—N1—H1C	122.2	C1^ii—C3—H3	120.3
C3^ii—C1—C2—C3	0 (3)	C1—C2—C3—C1^ii	0 (3)
N1—C1—C2—C3	178.7 (15)

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

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
O1—H1S···Br1	0.87	2.40	3.262 (16)	177
O1—H2S···Br1^iii	0.86	2.43	3.285 (15)	172
N1—H1A···O1^ii	0.87	2.23	2.887 (17)	132.9
N1—H1A···Br1^iv	0.87	2.81	3.311 (13)	118.4
N1—H1B···Br1^iv	0.88	2.70	3.311 (13)	127.9
N1—H1B···Br3	0.88	2.92	3.703 (12)	149.2
N1—H1C···Br3^v	0.86	2.77	3.487 (12)	142.1
N1—H1C···Br2^v	0.86	2.93	3.515 (15)	127.6

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