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For SiBr4 no crystal structures have been reported yet. In this work the crystal structures of SiBr4 were predicted by global lattice-energy minimizations using force-field methods. Over an energy range of 5 kJ mol−1 above the global minimum ten possible structures were found. Two of these structures were experimentally determined from X-ray synchrotron powder diffraction data: The low-temperature β phase crystallizes in P21/c, the high-temperature α phase in Pa\overline{3}. Temperature-dependant X-ray powder diffraction shows that the phase transition occurs at 168 K.

Supporting information

cif

Crystallographic Information File (CIF) https://doi.org/10.1107/S0108768109012051/bk5083sup1.cif
Contains datablocks global, alpha-SiBr4, beta-SiBr4

cif

Crystallographic Information File (CIF) https://doi.org/10.1107/S0108768109012051/bk5083sup2.cif
Rank 1 calculated structure for SiBr4

cif

Crystallographic Information File (CIF) https://doi.org/10.1107/S0108768109012051/bk5083sup3.cif
Rank 2 calculated structure for SiBr4

cif

Crystallographic Information File (CIF) https://doi.org/10.1107/S0108768109012051/bk5083sup4.cif
Rank 3 calculated structure for SiBr4

cif

Crystallographic Information File (CIF) https://doi.org/10.1107/S0108768109012051/bk5083sup5.cif
Rank 4 calculated structure for SiBr4

cif

Crystallographic Information File (CIF) https://doi.org/10.1107/S0108768109012051/bk5083sup6.cif
Rank 5 calculated structure for SiBr4

cif

Crystallographic Information File (CIF) https://doi.org/10.1107/S0108768109012051/bk5083sup7.cif
Rank 6 calculated structure for SiBr4

cif

Crystallographic Information File (CIF) https://doi.org/10.1107/S0108768109012051/bk5083sup8.cif
Rank 7 calculated structure for SiBr4

cif

Crystallographic Information File (CIF) https://doi.org/10.1107/S0108768109012051/bk5083sup9.cif
Rank 8 calculated structure for SiBr4

cif

Crystallographic Information File (CIF) https://doi.org/10.1107/S0108768109012051/bk5083sup10.cif
Rank 9 calculated structure for SiBr4

cif

Crystallographic Information File (CIF) https://doi.org/10.1107/S0108768109012051/bk5083sup11.cif
Rank 10 calculated structure for SiBr4

pdf

Portable Document Format (PDF) file https://doi.org/10.1107/S0108768109012051/bk5083sup12.pdf
Extra figures and tables of positional parameters

Computing details top

(alpha-SiBr4) Silicontetrabromide top
Crystal data top
Br4SiZ = 8
Mr = 347.69Dx = 3.308 Mg m3
Cubic, Pa3Melting point: 245 K
Hall symbol: -P 2ac 2abSynchrotron radiation, λ = 0.92103 Å
a = 11.17701 (7) ÅT = 237 K
V = 1396.29 (3) Å3cylinder, ? × ? × ? mm
Data collection top
'beamline X7B, NSLS,Brookhaven National Laboratory,Brookhaven, USA'
diffractometer
Data collection mode: transmission
Silicon double monochromatorScan method: step
Specimen mounting: '0.3 mm glass capillary'2θmin = 4.0°, 2θmax = 36.0°, 2θstep = 0.02°
Refinement top
Rp = 0.010Excluded region(s): 0 to 4 and 36 to 38 degrees unreliable due to beam dump
Rwp = 0.017Profile function: Fundamental parameters
Rexp = 0.02025 parameters
R(F2) = 0.00560
χ2 = NOT FOUNDBackground function: 'Chebyshev polynomial'
? data points
Crystal data top
Br4SiZ = 8
Mr = 347.69Synchrotron radiation, λ = 0.92103 Å
Cubic, Pa3T = 237 K
a = 11.17701 (7) Åcylinder, ? × ? × ? mm
V = 1396.29 (3) Å3
Data collection top
'beamline X7B, NSLS,Brookhaven National Laboratory,Brookhaven, USA'
diffractometer
Scan method: step
Specimen mounting: '0.3 mm glass capillary'2θmin = 4.0°, 2θmax = 36.0°, 2θstep = 0.02°
Data collection mode: transmission
Refinement top
Rp = 0.010χ2 = NOT FOUND
Rwp = 0.017? data points
Rexp = 0.02025 parameters
R(F2) = 0.00560
Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top
xyzBiso*/Beq
Si10.131 (1)0.131 (1)0.131 (1)5.22 (4)
Br10.2426 (6)0.2426 (6)0.2426 (6)5.22 (4)
Br20.0255 (2)0.0129 (6)0.2475 (3)5.22 (4)
Geometric parameters (Å, º) top
Si1—Br12.16 (2)Si1—Br22.201 (9)
Br1—Si1—Br2108.5 (5)Br2—Si1—Br2110.5 (5)
(beta-SiBr4) Silicontetrabromide top
Crystal data top
Br4SiV = 678.16 (4) Å3
Mr = 347.69Z = 4
Monoclinic, P21/cDx = 3.406 Mg m3
Hall symbol: -P 2ybcMelting point: 245 K
a = 10.1319 (4) ÅSynchrotron radiation, λ = 0.92103 Å
b = 6.7002 (2) ÅT = 147 K
c = 10.2389 (3) Åcylinder, ? × ? × ? mm
β = 102.665 (2)°
Data collection top
'beamline X7B, NSLS,Brookhaven National Laboratory,Brookhaven, USA'
diffractometer
Data collection mode: transmission
Silicon double monochromatorScan method: step
Specimen mounting: '0.3 mm glass capillary'2θmin = 4.0°, 2θmax = 36.0°, 2θstep = 0.02°
Refinement top
Rp = 0.013Excluded region(s): 0 to 4 and 36 to 38 degrees unreliable due to beam dump
Rwp = 0.023Profile function: Fundamental parameters
Rexp = 0.01949 parameters
R(F2) = 0.02541
χ2 = NOT FOUNDBackground function: 'Chebyshev polynomial'
? data points
Crystal data top
Br4Siβ = 102.665 (2)°
Mr = 347.69V = 678.16 (4) Å3
Monoclinic, P21/cZ = 4
a = 10.1319 (4) ÅSynchrotron radiation, λ = 0.92103 Å
b = 6.7002 (2) ÅT = 147 K
c = 10.2389 (3) Åcylinder, ? × ? × ? mm
Data collection top
'beamline X7B, NSLS,Brookhaven National Laboratory,Brookhaven, USA'
diffractometer
Scan method: step
Specimen mounting: '0.3 mm glass capillary'2θmin = 4.0°, 2θmax = 36.0°, 2θstep = 0.02°
Data collection mode: transmission
Refinement top
Rp = 0.013χ2 = NOT FOUND
Rwp = 0.023? data points
Rexp = 0.01949 parameters
R(F2) = 0.02541
Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top
xyzBiso*/Beq
Si10.2458 (4)0.5798 (10)0.6408 (3)3.17 (14)
Br10.1915870.8863840.5830293.17 (14)
Br20.2945000.4211930.4722093.17 (14)
Br30.0764490.4339430.7003623.17 (14)
Br40.4205040.5777610.8077203.17 (14)
Geometric parameters (Å, º) top
Si1—Br12.175 (3)Si1—Br32.175 (3)
Si1—Br22.175 (3)Si1—Br42.175 (3)
Br1—Si1—Br2109.47Br2—Si1—Br3109.47
Br1—Si1—Br3109.47Br2—Si1—Br4109.47
Br1—Si1—Br4109.47Br3—Si1—Br4109.47

Experimental details

(alpha-SiBr4)(beta-SiBr4)
Crystal data
Chemical formulaBr4SiBr4Si
Mr347.69347.69
Crystal system, space groupCubic, Pa3Monoclinic, P21/c
Temperature (K)237147
a, b, c (Å)11.17701 (7), 11.17701 (7), 11.17701 (7)10.1319 (4), 6.7002 (2), 10.2389 (3)
α, β, γ (°)90, 90, 9090, 102.665 (2), 90
V3)1396.29 (3)678.16 (4)
Z84
Radiation typeSynchrotron, λ = 0.92103 ÅSynchrotron, λ = 0.92103 Å
µ (mm1)??
Specimen shape, size (mm)Cylinder, ? × ? × ?Cylinder, ? × ? × ?
Data collection
Data collection method'beamline X7B, NSLS,Brookhaven National Laboratory,Brookhaven, USA''beamline X7B, NSLS,Brookhaven National Laboratory,Brookhaven, USA'
Specimen mounting'0.3 mm glass capillary''0.3 mm glass capillary'
Data collection modeTransmissionTransmission
Scan methodStepStep
2θ values (°)2θmin = 4.0 2θmax = 36.0 2θstep = 0.022θmin = 4.0 2θmax = 36.0 2θstep = 0.02
Refinement
R factors and goodness of fitRp = 0.010, Rwp = 0.017, Rexp = 0.020, R(F2) = 0.00560, χ2 = NOT FOUNDRp = 0.013, Rwp = 0.023, Rexp = 0.019, R(F2) = 0.02541, χ2 = NOT FOUND
No. of data points??
No. of parameters2549
No. of restraints??

Selected geometric parameters (Å, º) for (alpha-SiBr4) top
Si1—Br12.16 (2)Si1—Br22.201 (9)
Br1—Si1—Br2108.5 (5)Br2—Si1—Br2110.5 (5)
Selected geometric parameters (Å, º) for (beta-SiBr4) top
Si1—Br12.175 (3)Si1—Br32.175 (3)
Si1—Br22.175 (3)Si1—Br42.175 (3)
Br1—Si1—Br2109.47Br2—Si1—Br3109.47
Br1—Si1—Br3109.47Br2—Si1—Br4109.47
Br1—Si1—Br4109.47Br3—Si1—Br4109.47
 

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