Buy article online - an online subscription or single-article purchase is required to access this article.
Heptapraseodymium iron dodecaiodide or praseodymium dodecaiodo-ferro-
octahedro-hexapraseodymium, Pr
7I
12Fe (= Pr{Pr
6Fe}I
12), was obtained as black single crystals during investigations of the Pr-Fe-I system. It crystallizes with the Sc
7Cl
12N-type of structure. According to the formula Pr1{Pr2
6Fe}I1
6iI2
6i-a, it contains `isolated' {Pr2
6Fe} clusters, edge-capped by 12 I
- ligands, with Pr1 filling the otherwise empty octahedral holes between the I
- ions. Both Pr-Pr [3.9119 (8) and 3.9150 (8) Å] and Pr-Fe distances [2.7672 (5) Å] within the {Pr2
6Fe} cluster are in good agreement with those of similar compounds, as are the Pr-I distances. One of the Pr atoms and both I atoms occupy sites with symmetry 1 (Wyckhoff position 18
f). The second Pr atom (3
a) and the Fe atom (3
b) are situated in sites with symmetry
.
Supporting information
Key indicators
- Single-crystal X-ray study
- T = 293 K
- Mean (r-Fe) = 0.001 Å
- R factor = 0.046
- wR factor = 0.099
- Data-to-parameter ratio = 55.4
checkCIF/PLATON results
No syntax errors found
Alert level A
DIFF019_ALERT_1_A _diffrn_standards_number is missing
Number of standards used in measurement.
DIFF020_ALERT_1_A _diffrn_standards_interval_count and
_diffrn_standards_interval_time are missing. Number of measurements
between standards or time (min) between standards.
DIFF022_ALERT_1_A _diffrn_standards_decay_% is missing
Percentage decrease in standards intensity.
Alert level B
DIFMN02_ALERT_2_B The minimum difference density is < -0.1*ZMAX*1.00
_refine_diff_density_min given = -5.982
Test value = -5.900
PLAT098_ALERT_2_B Minimum (Negative) Residual Density ............ -5.98 e/A 3
Alert level C
DIFMN03_ALERT_1_C The minimum difference density is < -0.1*ZMAX*0.75
The relevant atom site should be identified.
PLAT199_ALERT_1_C Check the Reported _cell_measurement_temperature 293 K
PLAT200_ALERT_1_C Check the Reported _diffrn_ambient_temperature . 293 K
3 ALERT level A = In general: serious problem
2 ALERT level B = Potentially serious problem
3 ALERT level C = Check and explain
0 ALERT level G = General alerts; check
6 ALERT type 1 CIF construction/syntax error, inconsistent or missing data
2 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
0 ALERT type 4 Improvement, methodology, query or suggestion
Data collection: X-AREA (Stoe & Cie, 2001); 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, 2001); software used to prepare material for publication: SHELXL97.
Heptapraseodymium iron dodecaiodide
top
Crystal data top
FeI12Pr7 | Dx = 5.461 Mg m−3 |
Mr = 2565.02 | Mo Kα radiation, λ = 0.71073 Å |
Trigonal, R3 | Cell parameters from 13127 reflections |
Hall symbol: -R 3 | θ = 2.4–32.2° |
a = 15.8296 (10) Å | µ = 23.02 mm−1 |
c = 10.7833 (6) Å | T = 293 K |
V = 2340.0 (2) Å3 | Rhomb, black |
Z = 3 | 0.25 × 0.15 × 0.05 mm |
F(000) = 3225 | |
Data collection top
Stoe IPDS-II diffractometer | 1829 independent reflections |
Radiation source: fine-focus sealed tube | 1593 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.065 |
ω and φ scans | θmax = 32.2°, θmin = 2.4° |
Absorption correction: numerical [X-SHAPE (Stoe & Cie, 1999) and X-RED (Stoe & Cie, 2001)] | h = −23→23 |
Tmin = 0.027, Tmax = 0.324 | k = −23→23 |
13579 measured reflections | l = −15→16 |
Refinement top
Refinement on F2 | Primary atom site location: structure-invariant direct methods |
Least-squares matrix: full | Secondary atom site location: difference Fourier map |
R[F2 > 2σ(F2)] = 0.046 | w = 1/[σ2(Fo2) + (0.0261P)2 + 153.022P] where P = (Fo2 + 2Fc2)/3 |
wR(F2) = 0.099 | (Δ/σ)max = 0.001 |
S = 1.04 | Δρmax = 3.54 e Å−3 |
1829 reflections | Δρmin = −5.98 e Å−3 |
33 parameters | Extinction correction: SHELXL97 (Sheldrick, 1997), Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4 |
0 restraints | Extinction coefficient: 0.00067 (3) |
Special details top
Experimental. A suitable single-crystal was carefully selected under a polarizing microscope
and mounted in a glass capillary. The scattering intensities were collected on
an imaging plate diffractometer (IPDS II, Stoe & Cie) equipped with a
fine focus sealed tube X-ray source (Mo Kα, λ = 0.71073 Å) operating at 50 kV and 40 mA. Intensity data for the title compound were collected at room
temperature by ω-scans in 254 frames (0 < ω < 180°; φ = O°, 0 < ω <
74°; φ = 90°, Δω = 1°, exposure time of 5 min) in the 2 Θ range 2.9 to
64.8°. Structure solution and refinement were carried out using the programs
SIR92 (Altomare et al., 1993) and SHELXL97 (Sheldrick,
1997). A numerical absorption correction (X-RED (Stoe & Cie, 2001) was
applied after optimization of the crystal shape (X-SHAPE (Stoe & Cie,
1999)). The last cycles of refinement included atomic positions and
anisotropic parameters for all atoms. The final difference maps were free of
any chemically significant features. The refinement was based on F2 for ALL
reflections. |
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 | |
Pr2 | 0.44849 (3) | 0.62205 (3) | 0.01862 (4) | 0.02645 (14) | |
Pr1 | 0.3333 | 0.6667 | 0.6667 | 0.0507 (4) | |
I1 | 0.41239 (4) | 0.43177 (4) | 0.16421 (5) | 0.03380 (16) | |
I2 | 0.52062 (4) | 0.80126 (4) | 0.82596 (5) | 0.02966 (15) | |
Fe | 0.3333 | 0.6667 | 0.1667 | 0.0180 (4) | |
Atomic displacement parameters (Å2) top | U11 | U22 | U33 | U12 | U13 | U23 |
Pr2 | 0.0257 (2) | 0.0217 (2) | 0.0285 (2) | 0.00922 (15) | −0.00511 (14) | 0.00157 (14) |
Pr1 | 0.0282 (4) | 0.0282 (4) | 0.0957 (12) | 0.01410 (18) | 0.000 | 0.000 |
I1 | 0.0424 (3) | 0.0327 (3) | 0.0369 (3) | 0.0267 (2) | 0.0131 (2) | 0.0087 (2) |
I2 | 0.0314 (3) | 0.0299 (3) | 0.0285 (3) | 0.0159 (2) | 0.00662 (18) | 0.00437 (17) |
Fe | 0.0170 (6) | 0.0170 (6) | 0.0200 (10) | 0.0085 (3) | 0.000 | 0.000 |
Geometric parameters (Å, º) top
Pr2—Fe | 2.7672 (5) | Pr1—I2 | 3.1564 (6) |
Pr2—I1 | 3.1847 (7) | Pr1—I2vi | 3.1564 (6) |
Pr2—I1i | 3.1950 (7) | Pr1—I2x | 3.1564 (6) |
Pr2—I2ii | 3.2292 (7) | I1—Pr2v | 3.1951 (7) |
Pr2—I2iii | 3.2367 (7) | I1—Pr2iv | 3.3674 (7) |
Pr2—I1iv | 3.3674 (7) | I2—Pr2xi | 3.2292 (7) |
Pr2—Pr2v | 3.9119 (8) | I2—Pr2xii | 3.2367 (7) |
Pr2—Pr2i | 3.9119 (8) | Fe—Pr2v | 2.7672 (5) |
Pr2—Pr2vi | 3.9150 (8) | Fe—Pr2vi | 2.7672 (5) |
Pr2—Pr2vii | 3.9150 (8) | Fe—Pr2vii | 2.7672 (5) |
Pr1—I2viii | 3.1564 (6) | Fe—Pr2i | 2.7672 (5) |
Pr1—I2vii | 3.1564 (6) | Fe—Pr2xiii | 2.7673 (5) |
Pr1—I2ix | 3.1564 (6) | | |
| | | |
Fe—Pr2—I1 | 97.320 (16) | I1iv—Pr2—Pr2vii | 134.585 (15) |
Fe—Pr2—I1i | 97.080 (16) | Pr2v—Pr2—Pr2vii | 90.0 |
I1—Pr2—I1i | 89.147 (11) | Pr2i—Pr2—Pr2vii | 59.973 (7) |
Fe—Pr2—I2ii | 97.798 (16) | Pr2vi—Pr2—Pr2vii | 60.0 |
I1—Pr2—I2ii | 164.88 (2) | I2viii—Pr1—I2vii | 180.0 |
I1i—Pr2—I2ii | 88.923 (18) | I2viii—Pr1—I2ix | 93.198 (13) |
Fe—Pr2—I2iii | 97.624 (16) | I2vii—Pr1—I2ix | 86.802 (13) |
I1—Pr2—I2iii | 87.705 (19) | I2viii—Pr1—I2 | 86.803 (13) |
I1i—Pr2—I2iii | 165.24 (2) | I2vii—Pr1—I2 | 93.197 (13) |
I2ii—Pr2—I2iii | 90.36 (2) | I2ix—Pr1—I2 | 180.0 |
Fe—Pr2—I1iv | 179.395 (18) | I2viii—Pr1—I2vi | 86.803 (13) |
I1—Pr2—I1iv | 83.112 (17) | I2vii—Pr1—I2vi | 93.197 (13) |
I1i—Pr2—I1iv | 83.344 (18) | I2ix—Pr1—I2vi | 86.803 (13) |
I2ii—Pr2—I1iv | 81.771 (17) | I2—Pr1—I2vi | 93.197 (13) |
I2iii—Pr2—I1iv | 81.964 (18) | I2viii—Pr1—I2x | 93.198 (13) |
Fe—Pr2—Pr2v | 45.022 (6) | I2vii—Pr1—I2x | 86.802 (13) |
I1—Pr2—Pr2v | 52.302 (15) | I2ix—Pr1—I2x | 93.197 (13) |
I1i—Pr2—Pr2v | 94.597 (18) | I2—Pr1—I2x | 86.803 (13) |
I2ii—Pr2—Pr2v | 142.815 (14) | I2vi—Pr1—I2x | 180.0 |
I2iii—Pr2—Pr2v | 94.865 (14) | Pr2—I1—Pr2v | 75.64 (2) |
I1iv—Pr2—Pr2v | 135.413 (15) | Pr2—I1—Pr2iv | 96.888 (17) |
Fe—Pr2—Pr2i | 45.022 (6) | Pr2v—I1—Pr2iv | 172.53 (2) |
I1—Pr2—Pr2i | 95.633 (19) | Pr1—I2—Pr2xi | 87.532 (16) |
I1i—Pr2—Pr2i | 52.061 (15) | Pr1—I2—Pr2xii | 87.402 (16) |
I2ii—Pr2—Pr2i | 94.987 (14) | Pr2xi—I2—Pr2xii | 74.53 (2) |
I2iii—Pr2—Pr2i | 142.641 (15) | Pr2v—Fe—Pr2vi | 89.955 (12) |
I1iv—Pr2—Pr2i | 135.395 (16) | Pr2v—Fe—Pr2vii | 180.0 |
Pr2v—Pr2—Pr2i | 60.051 (14) | Pr2vi—Fe—Pr2vii | 90.045 (12) |
Fe—Pr2—Pr2vi | 44.977 (6) | Pr2v—Fe—Pr2i | 90.046 (12) |
I1—Pr2—Pr2vi | 94.706 (18) | Pr2vi—Fe—Pr2i | 180.0 |
I1i—Pr2—Pr2vi | 142.053 (14) | Pr2vii—Fe—Pr2i | 89.954 (12) |
I2ii—Pr2—Pr2vi | 96.025 (13) | Pr2v—Fe—Pr2 | 89.956 (12) |
I2iii—Pr2—Pr2vi | 52.650 (15) | Pr2vi—Fe—Pr2 | 90.045 (12) |
I1iv—Pr2—Pr2vi | 134.602 (16) | Pr2vii—Fe—Pr2 | 90.045 (12) |
Pr2v—Pr2—Pr2vi | 59.973 (7) | Pr2i—Fe—Pr2 | 89.956 (12) |
Pr2i—Pr2—Pr2vi | 90.0 | Pr2v—Fe—Pr2xiii | 90.044 (12) |
Fe—Pr2—Pr2vii | 44.977 (6) | Pr2vi—Fe—Pr2xiii | 89.955 (12) |
I1—Pr2—Pr2vii | 142.294 (15) | Pr2vii—Fe—Pr2xiii | 89.954 (12) |
I1i—Pr2—Pr2vii | 95.402 (18) | Pr2i—Fe—Pr2xiii | 90.044 (12) |
I2ii—Pr2—Pr2vii | 52.824 (14) | Pr2—Fe—Pr2xiii | 179.999 (13) |
I2iii—Pr2—Pr2vii | 95.900 (13) | | |
Symmetry codes: (i) x−y+2/3, x+1/3, −z+1/3; (ii) x, y, z−1; (iii) −x+y, −x+1, z−1; (iv) −x+1, −y+1, −z; (v) y−1/3, −x+y+1/3, −z+1/3; (vi) −x+y, −x+1, z; (vii) −y+1, x−y+1, z; (viii) y−1/3, −x+y+1/3, −z+4/3; (ix) −x+2/3, −y+4/3, −z+4/3; (x) x−y+2/3, x+1/3, −z+4/3; (xi) x, y, z+1; (xii) −y+1, x−y+1, z+1; (xiii) −x+2/3, −y+4/3, −z+1/3. |
Subscribe to Acta Crystallographica Section E: Crystallographic Communications
The full text of this article is available to subscribers to the journal.
If you have already registered and are using a computer listed in your registration details, please email
support@iucr.org for assistance.