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The room temperature single-crystal X-ray structure determination of the title compound, PrI3·9H2O, better represented as [Pr(OH2)9]I3, shows unequivocally that it belongs to the structure type preferably adopted by hydrates of the lighter rare earth iodides (La-Ho). The praseodymium cation is coordinated by nine water mol­ecules in the form of a tricapped trigonal prism with the metal atom situated on a site of crystallographic symmetry mm2.

Supporting information

cif

Crystallographic Information File (CIF) https://doi.org/10.1107/S1600536805012857/wm6064sup1.cif
Contains datablocks I, global

hkl

Structure factor file (CIF format) https://doi.org/10.1107/S1600536805012857/wm6064Isup2.hkl
Contains datablock I

Key indicators

  • Single-crystal X-ray study
  • T = 298 K
  • Mean [sigma](r-O) = 0.007 Å
  • H-atom completeness 1%
  • R factor = 0.050
  • wR factor = 0.136
  • Data-to-parameter ratio = 24.8

checkCIF/PLATON results

No syntax errors found



Alert level A PLAT029_ALERT_3_A _diffrn_measured_fraction_theta_full Low ....... 0.92
Author Response: A missing cusp of data due to datacollection by rotation around the spindle axis only (IPDS-I). It was impossible to achieve substantial improvement by remount the crystal as it has to be kept under mother liquid and always adopted a preferred orientation.


Alert level C CHEMW03_ALERT_2_C The ratio of given/expected molecular weight as calculated from the _atom_site* data lies outside the range 0.99 <> 1.01 From the CIF: _cell_formula_units_Z 2 From the CIF: _chemical_formula_weight 683.75 TEST: Calculate formula weight from _atom_site_* atom mass num sum H 1.01 0.00 0.00 O 16.00 9.00 143.99 I 126.90 3.00 380.71 Pr 140.91 1.00 140.91 Calculated formula weight 665.61 CRYSC01_ALERT_1_C The word below has not been recognised as a standard identifier. to REFLT03_ALERT_3_C Reflection count < 95% complete From the CIF: _diffrn_reflns_theta_max 27.72 From the CIF: _diffrn_reflns_theta_full 27.72 From the CIF: _reflns_number_total 1016 TEST2: Reflns within _diffrn_reflns_theta_max Count of symmetry unique reflns 1108 Completeness (_total/calc) 91.70% PLAT041_ALERT_1_C Calc. and Rep. SumFormula Strings Differ .... ? PLAT043_ALERT_1_C Check Reported Molecular Weight ................ 683.75 PLAT044_ALERT_1_C Calculated and Reported Dx Differ .............. ? PLAT068_ALERT_1_C Reported F000 Differs from Calcd (or Missing)... ? PLAT242_ALERT_2_C Check Low Ueq as Compared to Neighbors for Pr PLAT431_ALERT_2_C Short Inter HL..A Contact I1 .. O1 .. 3.45 Ang. PLAT790_ALERT_4_C Centre of Gravity not Within Unit Cell: Resd. # 3 I
Alert level G FORMU01_ALERT_2_G There is a discrepancy between the atom counts in the _chemical_formula_sum and the formula from the _atom_site* data. Atom count from _chemical_formula_sum:H18 I3 O9 Pr1 Atom count from the _atom_site data: I3 O9 Pr1 CELLZ01_ALERT_1_G Difference between formula and atom_site contents detected. CELLZ01_ALERT_1_G WARNING: H atoms missing from atom site list. Is this intentional? From the CIF: _cell_formula_units_Z 2 From the CIF: _chemical_formula_sum H18 I3 O9 Pr TEST: Compare cell contents of formula and atom_site data atom Z*formula cif sites diff H 36.00 0.00 36.00 I 6.00 6.00 0.00 O 18.00 18.00 0.00 Pr 2.00 2.00 0.00
1 ALERT level A = In general: serious problem 0 ALERT level B = Potentially serious problem 10 ALERT level C = Check and explain 3 ALERT level G = General alerts; check 7 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 2 ALERT type 3 Indicator that the structure quality may be low 1 ALERT type 4 Improvement, methodology, query or suggestion

Computing details top

Data collection: X-AREA (Stoe & Cie, 2002); cell refinement: X-AREA; data reduction: X-AREA; program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: DIAMOND (Brandenburg, 1996); software used to prepare material for publication: SHELXL97.

praseodymium triiodide nonahydrate top
Crystal data top
PrI3·9H20F(000) = 616
Mr = 683.75Dx = 2.700 Mg m3
Orthorhombic, PmmnMo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ab 2aCell parameters from 2000 reflections
a = 11.720 (2) Åθ = 1.9–27.7°
b = 8.0163 (15) ŵ = 8.42 mm1
c = 8.952 (2) ÅT = 298 K
V = 841.1 (3) Å3Irregular, pale yellow to green
Z = 20.30 × 0.10 × 0.05 mm
Data collection top
Stoe IPDS-I
diffractometer
1016 independent reflections
Radiation source: fine-focus sealed tube870 reflections with I > 2σ(I)
Graphite monochromatorRint = 0.072
Detector resolution: not measured pixels mm-1θmax = 27.7°, θmin = 1.9°
φ scansh = 1515
Absorption correction: numerical
X-RED (Stoe & Cie, 2002) and X-SHAPE (Stoe & Cie, 1999)
k = 99
Tmin = 0.151, Tmax = 0.607l = 1111
8456 measured reflections
Refinement top
Refinement on F2Secondary atom site location: difference Fourier map
Least-squares matrix: fullH-atom parameters not defined
R[F2 > 2σ(F2)] = 0.050 w = 1/[σ2(Fo2) + (0.0732P)2 + 3.5369P]
where P = (Fo2 + 2Fc2)/3
wR(F2) = 0.136(Δ/σ)max < 0.001
S = 1.09Δρmax = 1.12 e Å3
1016 reflectionsΔρmin = 1.62 e Å3
41 parametersExtinction correction: SHELXL97, Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4
0 restraintsExtinction coefficient: 0.030 (3)
Primary atom site location: structure-invariant direct methods
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 with an imaging plate diffractometer (Stoe IPDS-I) equipped with a fine focus sealed tube X-ray source (Mo Kα, λ = 0.71073 Å) operating at 50 kV and 30 mA. Intensity data for [Pr(OH2)9]I3 were collected at 298 K by φ scans in 100 frames (0 < φ < 200° exposure time of 5 min) in the 2Θ range 5–56 °·Structure solution and refinement were carried out using the program 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 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-factorsbased 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
xyzUiso*/Ueq
Pr0.25000.25000.33185 (8)0.0438 (3)
I10.00245 (6)0.75000.17176 (8)0.0658 (4)
I20.25000.75000.29036 (15)0.0647 (4)
O10.0570 (6)0.25000.2053 (9)0.069 (2)
O20.25000.0422 (12)0.1196 (10)0.074 (2)
O30.3788 (4)0.4737 (8)0.4354 (6)0.0663 (16)
O40.25000.25000.6158 (12)0.064 (3)
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
Pr0.0313 (4)0.0669 (6)0.0333 (4)0.0000.0000.000
I10.0653 (6)0.0916 (8)0.0405 (5)0.0000.0033 (3)0.000
I20.0541 (6)0.0834 (9)0.0567 (7)0.0000.0000.000
O10.054 (4)0.104 (7)0.048 (4)0.0000.016 (3)0.000
O20.061 (4)0.096 (7)0.064 (5)0.0000.0000.017 (5)
O30.053 (3)0.088 (5)0.057 (3)0.016 (2)0.002 (2)0.004 (3)
O40.050 (5)0.101 (9)0.041 (5)0.0000.0000.000
Geometric parameters (Å, º) top
Pr—O32.520 (6)Pr—O2ii2.527 (9)
Pr—O3i2.520 (6)Pr—O12.530 (7)
Pr—O3ii2.520 (6)Pr—O1ii2.530 (7)
Pr—O3iii2.520 (6)Pr—O42.542 (11)
Pr—O22.527 (9)
O3—Pr—O3i73.6 (3)O3iii—Pr—O1134.43 (14)
O3—Pr—O3ii136.9 (3)O2—Pr—O170.32 (15)
O3i—Pr—O3ii90.7 (3)O2ii—Pr—O170.32 (15)
O3—Pr—O3iii90.7 (3)O3—Pr—O1ii68.24 (17)
O3i—Pr—O3iii136.9 (3)O3i—Pr—O1ii134.43 (14)
O3ii—Pr—O3iii73.6 (3)O3ii—Pr—O1ii134.43 (14)
O3—Pr—O2138.20 (16)O3iii—Pr—O1ii68.24 (17)
O3i—Pr—O2138.20 (16)O2—Pr—O1ii70.32 (15)
O3ii—Pr—O278.9 (2)O2ii—Pr—O1ii70.32 (15)
O3iii—Pr—O278.9 (2)O1—Pr—O1ii126.8 (4)
O3—Pr—O2ii78.9 (2)O3—Pr—O468.43 (13)
O3i—Pr—O2ii78.9 (2)O3i—Pr—O468.43 (13)
O3ii—Pr—O2ii138.20 (16)O3ii—Pr—O468.43 (13)
O3iii—Pr—O2ii138.20 (16)O3iii—Pr—O468.43 (13)
O2—Pr—O2ii82.5 (4)O2—Pr—O4138.8 (2)
O3—Pr—O1134.43 (14)O2ii—Pr—O4138.8 (2)
O3i—Pr—O168.24 (17)O1—Pr—O4116.60 (19)
O3ii—Pr—O168.24 (17)O1ii—Pr—O4116.60 (19)
Symmetry codes: (i) x+1/2, y, z; (ii) x+1/2, y+1/2, z; (iii) x, y+1/2, z.
 

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