Diamminehexabromodiscandium(III)

The title compound, [Sc₂Br₆(NH₃)₂], was obtained by the reaction of ammonium bromide, (NH₄)Br, with scandium metal in a sealed tantalum metal container. The crystal structure contains zigzag chains of edge-connected [Sc(NH₃)Br₅] octahedra according to the formulation [Sc(NH₃)_1/1Br_1/1Br_4/2]. Sc(NH₃)Br₃ is isotypic with Sc(NH₃)Cl₃.

Key indicators

• Single-crystal X-ray study
• T = 293 K
• Mean [sigma](Sc-N) = 0.008 Å
• R factor = 0.040
• wR factor = 0.096
• Data-to-parameter ratio = 37.3

checkCIF/PLATON results

No syntax errors found



Alert level B
PLAT029_ALERT_3_B _diffrn_measured_fraction_theta_full Low .......       0.99

Alert level C
GOODF01_ALERT_2_C  The least squares goodness of fit parameter lies
            outside the range 0.80 <> 2.00
            Goodness of fit given =      0.789
PLAT041_ALERT_1_C Calc. and Rep. SumFormula Strings    Differ ....          ?
PLAT042_ALERT_1_C Calc. and Rep. MoietyFormula Strings Differ ....          ?
PLAT155_ALERT_4_C The Triclinic Unitcell is NOT Reduced ..........          ?
PLAT156_ALERT_4_C Axial System Input Cell not Standard ...........          ?
PLAT420_ALERT_2_C D-H Without Acceptor       N1     -   H1A    ...          ?
PLAT420_ALERT_2_C D-H Without Acceptor       N2     -   H2A    ...          ?

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

   2 ALERT type 1 CIF construction/syntax error, inconsistent or missing data
   3 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

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Computing details

Data collection: X-AREA (Stoe & Cie, 2002); cell refinement: X-AREA; data reduction: X-AREA; program(s) used to solve structure: SIR92 (Altomare et al., 1993); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: DIAMOND (Brandenburg, 1996); software used to prepare material for publication: Details?.

Diamminehexabromodiscandium(III)

Crystal data

[Sc2Br6(NH3)2]	Z = 2
Mr = 603.45	F(000) = 544
Triclinic, P1	Dx = 3.192 Mg m^−3
Hall symbol: -P 1	Melting point: unknown K
a = 7.392 (2) Å	Mo Kα radiation, λ = 0.71073 Å
b = 9.578 (2) Å	Cell parameters from 3629 reflections
c = 9.551 (2) Å	θ = 1.3–29.8°
α = 73.07 (2)°	µ = 20.12 mm^−1
β = 80.04 (2)°	T = 293 K
γ = 77.82 (2)°	Column, colourless
V = 627.8 (3) Å^3	0.25 × 0.1 × 0.1 mm

Data collection

Stoe IPDS II diffractometer	3470 independent reflections
Radiation source: fine-focus sealed tube	1750 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.072
Detector resolution: not measured pixels mm^-1	θmax = 29.6°, θmin = 2.3°
ω and φ scans	h = −10→10
Absorption correction: numerical The absorption correction (X-RED; Stoe & Cie, 2001) was performed after optimizing the crystal shape using X-SHAPE (Stoe & Cie, 1999).	k = −13→13
Tmin = 0.052, Tmax = 0.155	l = −13→13
9270 measured reflections

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)] = 0.040	H-atom parameters constrained
wR(F^2) = 0.096	w = 1/[σ^2(Fo^2) + (0.043P)^2] where P = (Fo^2 + 2Fc^2)/3
S = 0.79	(Δ/σ)max = 0.001
3470 reflections	Δρmax = 1.06 e Å^−3
93 parameters	Δρmin = −1.19 e Å^−3
0 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: 0.0021 (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
Sc1	0.0800 (2)	0.94111 (15)	0.69559 (16)	0.0309 (3)
Br11	−0.21509 (14)	1.06539 (10)	0.81959 (11)	0.0490 (2)
Br12	0.09954 (11)	1.16842 (9)	0.45800 (9)	0.0363 (2)
Br1	0.08889 (10)	0.69948 (9)	0.91996 (9)	0.0350 (2)
Br2	0.40163 (10)	0.79309 (8)	0.58317 (9)	0.0370 (2)
Sc2	0.4011 (2)	0.55114 (15)	0.80663 (16)	0.0315 (3)
Br21	0.41246 (11)	0.32866 (9)	1.04857 (10)	0.0366 (2)
Br22	0.23220 (14)	0.42413 (10)	0.68373 (11)	0.0479 (2)
N1	0.2690 (11)	1.0360 (8)	0.7911 (9)	0.0495 (19)
H1A	0.3872	1.0048	0.7601	0.115 (19)*
H1B	0.2504	1.0063	0.8890	0.115 (19)*
H1C	0.2442	1.1345	0.7618	0.115 (19)*
N2	0.6822 (10)	0.4583 (8)	0.7072 (9)	0.0471 (18)
H2A	0.7703	0.4899	0.7367	0.115 (19)*
H2B	0.6886	0.4883	0.6094	0.115 (19)*
H2C	0.6990	0.3598	0.7362	0.115 (19)*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Sc1	0.0288 (6)	0.0323 (7)	0.0310 (7)	0.0000 (5)	−0.0082 (5)	−0.0085 (6)
Br11	0.0474 (5)	0.0466 (5)	0.0440 (5)	0.0099 (4)	−0.0007 (4)	−0.0140 (4)
Br12	0.0387 (4)	0.0343 (4)	0.0369 (5)	−0.0102 (3)	−0.0139 (3)	−0.0027 (3)
Br1	0.0280 (4)	0.0367 (4)	0.0328 (4)	0.0000 (3)	−0.0024 (3)	−0.0022 (3)
Br2	0.0287 (4)	0.0386 (5)	0.0337 (5)	0.0007 (3)	−0.0019 (3)	0.0001 (4)
Sc2	0.0300 (6)	0.0308 (7)	0.0313 (7)	−0.0003 (5)	−0.0078 (5)	−0.0055 (6)
Br21	0.0360 (4)	0.0341 (4)	0.0383 (5)	−0.0083 (3)	−0.0144 (3)	−0.0003 (3)
Br22	0.0609 (6)	0.0459 (5)	0.0434 (5)	−0.0131 (4)	−0.0148 (4)	−0.0141 (4)
N1	0.060 (5)	0.044 (4)	0.050 (5)	−0.012 (3)	−0.021 (4)	−0.011 (3)
N2	0.043 (4)	0.045 (4)	0.044 (4)	0.009 (3)	−0.004 (3)	−0.010 (3)

Geometric parameters (Å, º)

Sc1—N1	2.252 (7)	Sc2—Br22	2.5293 (18)
Sc1—Br11	2.5316 (18)	Sc2—Br21	2.6477 (18)
Sc1—Br1	2.6548 (18)	Sc2—Br21^ii	2.7190 (18)
Sc1—Br12	2.6555 (19)	Br21—Sc2^ii	2.7190 (18)
Sc1—Br12^i	2.6779 (17)	N1—H1A	0.8900
Sc1—Br2	2.7197 (17)	N1—H1B	0.8900
Br12—Sc1^i	2.6779 (17)	N1—H1C	0.8900
Br1—Sc2	2.6769 (18)	N2—H2A	0.8900
Br2—Sc2	2.6542 (18)	N2—H2B	0.8900
Sc2—N2	2.244 (7)	N2—H2C	0.8900
N1—Sc1—Br11	93.8 (2)	Br21—Sc2—Br2	172.99 (6)
N1—Sc1—Br1	92.4 (2)	N2—Sc2—Br1	171.1 (2)
Br11—Sc1—Br1	91.10 (6)	Br22—Sc2—Br1	94.51 (6)
N1—Sc1—Br12	87.8 (2)	Br21—Sc2—Br1	92.25 (6)
Br11—Sc1—Br12	94.50 (6)	Br2—Sc2—Br1	85.59 (5)
Br1—Sc1—Br12	174.38 (6)	N2—Sc2—Br21^ii	86.6 (2)
N1—Sc1—Br12^i	170.1 (2)	Br22—Sc2—Br21^ii	176.44 (7)
Br11—Sc1—Br12^i	94.49 (6)	Br21—Sc2—Br21^ii	84.05 (5)
Br1—Sc1—Br12^i	92.78 (6)	Br2—Sc2—Br21^ii	89.16 (6)
Br12—Sc1—Br12^i	86.30 (5)	Br1—Sc2—Br21^ii	86.49 (5)
N1—Sc1—Br2	84.9 (2)	Sc2—Br21—Sc2^ii	95.95 (5)
Br11—Sc1—Br2	175.57 (7)	Sc1—N1—H1A	109.5
Br1—Sc1—Br2	84.73 (5)	Sc1—N1—H1B	109.5
Br12—Sc1—Br2	89.69 (6)	H1A—N1—H1B	109.5
Br12^i—Sc1—Br2	87.21 (5)	Sc1—N1—H1C	109.5
Sc1—Br12—Sc1^i	93.70 (5)	H1A—N1—H1C	109.5
Sc1—Br1—Sc2	95.32 (6)	H1B—N1—H1C	109.5
Sc2—Br2—Sc1	94.33 (6)	Sc2—N2—H2A	109.5
N2—Sc2—Br22	92.8 (2)	Sc2—N2—H2B	109.5
N2—Sc2—Br21	92.6 (2)	H2A—N2—H2B	109.5
Br22—Sc2—Br21	92.49 (6)	Sc2—N2—H2C	109.5
N2—Sc2—Br2	88.7 (2)	H2A—N2—H2C	109.5
Br22—Sc2—Br2	94.32 (6)	H2B—N2—H2C	109.5

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

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
N1—H1B···Br11^iii	0.89	2.64	3.532 (8)	175
N1—H1C···Br22^iv	0.89	2.64	3.520 (8)	170
N2—H2B···Br22^v	0.89	2.68	3.556 (8)	171
N2—H2C···Br11^vi	0.89	2.66	3.551 (7)	174

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