Buy article online - an online subscription or single-article purchase is required to access this article.
Europium triborate, EuB3O6, has been grown from a strontium borate flux. It crystallizes in the space group I2/a and is a member of the isostructural series REB3O6 (RE = La, Ce, Pr, Nd, Sm, Gd, Tb). Its structure consists of chains of [B6O12]n6- building units, that run parallel to the c axis, and tenfold coordinated Eu3+.
Supporting information
Key indicators
- Single-crystal X-ray study
- T = 293 K
- Mean (O-B) = 0.005 Å
- R factor = 0.047
- wR factor = 0.106
- Data-to-parameter ratio = 25.5
checkCIF/PLATON results
No syntax errors found
Alert level C
PLAT128_ALERT_4_C Non-standard setting of Space group C2/c .... I2/a
PLAT250_ALERT_2_C Large U3/U1 Ratio for Average U(i,j) Tensor .... 2.22
0 ALERT level A = In general: serious problem
0 ALERT level B = Potentially serious problem
2 ALERT level C = Check and explain
0 ALERT level G = General alerts; check
0 ALERT type 1 CIF construction/syntax error, inconsistent or missing data
1 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
1 ALERT type 4 Improvement, methodology, query or suggestion
Data collection: MACH3 Server Software (Enraf-Nonius, 1993); cell refinement: MACH3 Server Software; data reduction: MolEN (Fair, 1990); program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: ATOMS (Dowty, 2002); software used to prepare material for publication: SHELXL97.
Europium(III) trioxoborate
top
Crystal data top
EuB3O6 | F(000) = 504 |
Mr = 280.38 | Dx = 4.716 Mg m−3 |
Monoclinic, I2/a | Mo Kα radiation, λ = 0.71073 Å |
Hall symbol: -I 2ya | Cell parameters from 25 reflections |
a = 6.2830 (9) Å | θ = 24.8–30.1° |
b = 8.0331 (6) Å | µ = 15.82 mm−1 |
c = 7.8406 (7) Å | T = 293 K |
β = 93.70 (1)° | Parallelepiped, colourless |
V = 394.91 (7) Å3 | 0.18 × 0.15 × 0.13 mm |
Z = 4 | |
Data collection top
Nonius MACH3 four-circle diffractometer | 1140 reflections with I > 2σ(I) |
Radiation source: fine-focus sealed X-ray tube | Rint = 0.070 |
Graphite monochromator | θmax = 39.9°, θmin = 3.6° |
ω/2θ scans | h = −11→11 |
Absorption correction: ψ scan (MolEN; Fair, 1990) | k = −14→14 |
Tmin = 0.068, Tmax = 0.128 | l = −14→14 |
4454 measured reflections | 3 standard reflections every 100 reflections |
1222 independent reflections | intensity decay: 1.0% |
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)] = 0.047 | w = 1/[σ2(Fo2) + (0.0606P)2 + 3.5865P] where P = (Fo2 + 2Fc2)/3 |
wR(F2) = 0.107 | (Δ/σ)max < 0.001 |
S = 1.09 | Δρmax = 4.50 e Å−3 |
1222 reflections | Δρmin = −3.86 e Å−3 |
48 parameters | Extinction correction: SHELXL97, Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4 |
0 restraints | Extinction coefficient: 0.0093 (13) |
Special details top
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 | |
Eu | 0.2500 | 0.29835 (3) | 0.5000 | 0.0043 (1) | |
O1 | −0.1029 (6) | 0.3881 (5) | 0.6044 (4) | 0.0080 (5) | |
O2 | 0.3011 (7) | 0.0906 (4) | 0.2977 (4) | 0.0093 (6) | |
O3 | 0.6057 (7) | 0.1862 (5) | 0.6011 (4) | 0.0072 (5) | |
B1 | 0.3612 (8) | −0.0648 (6) | 0.2743 (5) | 0.0056 (6) | |
B2 | 0.7500 | 0.2798 (8) | 0.5000 | 0.0040 (9) | |
Atomic displacement parameters (Å2) top | U11 | U22 | U33 | U12 | U13 | U23 |
Eu | 0.00551 (18) | 0.00524 (15) | 0.00330 (13) | 0.000 | 0.00048 (7) | 0.000 |
O1 | 0.0084 (14) | 0.0105 (13) | 0.0048 (9) | −0.0025 (11) | 0.0012 (8) | −0.0025 (9) |
O2 | 0.0169 (16) | 0.0054 (12) | 0.0067 (10) | 0.0034 (12) | 0.0011 (9) | −0.0006 (9) |
O3 | 0.0080 (16) | 0.0085 (12) | 0.0065 (10) | 0.0020 (11) | 0.0011 (9) | 0.0052 (9) |
B1 | 0.0087 (19) | 0.0060 (15) | 0.0027 (12) | 0.0005 (14) | 0.0006 (11) | −0.0001 (10) |
B2 | 0.008 (3) | 0.0029 (19) | 0.0020 (17) | 0.000 | 0.0007 (15) | 0.000 |
Geometric parameters (Å, º) top
Eu—O2 | 2.338 (3) | Eu—O1v | 2.789 (4) |
Eu—O2i | 2.338 (3) | Eu—B1ii | 3.082 (4) |
Eu—O3i | 2.492 (4) | Eu—B1iii | 3.082 (4) |
Eu—O3 | 2.492 (4) | B1—O1vi | 1.415 (5) |
Eu—O2ii | 2.499 (3) | B1—O2 | 1.322 (6) |
Eu—O2iii | 2.499 (3) | B1—O3vii | 1.388 (6) |
Eu—O1 | 2.518 (4) | B2—O1viii | 1.478 (5) |
Eu—O1i | 2.518 (4) | B2—O3ix | 1.451 (5) |
Eu—O1iv | 2.789 (4) | | |
| | | |
O2—Eu—O2i | 89.02 (17) | O3i—Eu—O1v | 87.70 (12) |
O2—Eu—O3i | 71.68 (13) | O3—Eu—O1v | 133.93 (12) |
O2i—Eu—O3i | 78.37 (14) | O2ii—Eu—O1v | 88.41 (10) |
O2—Eu—O3 | 78.37 (14) | O2iii—Eu—O1v | 51.94 (10) |
O2i—Eu—O3 | 71.68 (13) | O1—Eu—O1v | 63.58 (13) |
O3i—Eu—O3 | 137.59 (18) | O1i—Eu—O1v | 85.88 (8) |
O2—Eu—O2ii | 150.82 (13) | O1iv—Eu—O1v | 50.73 (14) |
O2i—Eu—O2ii | 68.61 (14) | O2—Eu—B1ii | 159.05 (14) |
O3i—Eu—O2ii | 118.95 (13) | O2i—Eu—B1ii | 93.25 (11) |
O3—Eu—O2ii | 76.93 (13) | O3i—Eu—B1ii | 129.16 (12) |
O2—Eu—O2iii | 68.61 (14) | O3—Eu—B1ii | 82.58 (13) |
O2i—Eu—O2iii | 150.82 (13) | O2ii—Eu—B1ii | 24.70 (11) |
O3i—Eu—O2iii | 76.93 (13) | O2iii—Eu—B1ii | 114.42 (11) |
O3—Eu—O2iii | 118.95 (13) | O1—Eu—B1ii | 74.90 (12) |
O2ii—Eu—O2iii | 138.23 (16) | O1i—Eu—B1ii | 82.15 (12) |
O2—Eu—O1 | 125.93 (13) | O1iv—Eu—B1ii | 27.32 (10) |
O2i—Eu—O1 | 79.69 (13) | O1v—Eu—B1ii | 68.49 (10) |
O3i—Eu—O1 | 54.27 (11) | O2—Eu—B1iii | 93.25 (11) |
O3—Eu—O1 | 142.26 (11) | O2i—Eu—B1iii | 159.05 (15) |
O2ii—Eu—O1 | 69.92 (12) | O3i—Eu—B1iii | 82.58 (13) |
O2iii—Eu—O1 | 98.01 (12) | O3—Eu—B1iii | 129.16 (13) |
O2—Eu—O1i | 79.69 (13) | O2ii—Eu—B1iii | 114.42 (11) |
O2i—Eu—O1i | 125.93 (13) | O2iii—Eu—B1iii | 24.70 (11) |
O3i—Eu—O1i | 142.26 (11) | O1—Eu—B1iii | 82.15 (12) |
O3—Eu—O1i | 54.27 (11) | O1i—Eu—B1iii | 74.90 (12) |
O2ii—Eu—O1i | 98.01 (12) | O1iv—Eu—B1iii | 68.49 (10) |
O2iii—Eu—O1i | 69.92 (12) | O1v—Eu—B1iii | 27.32 (10) |
O1—Eu—O1i | 146.77 (18) | B1ii—Eu—B1iii | 92.01 (17) |
O2—Eu—O1iv | 141.85 (12) | O2—B1—O3vii | 126.6 (4) |
O2i—Eu—O1iv | 120.15 (10) | O2—B1—O1vi | 116.7 (4) |
O3i—Eu—O1iv | 133.93 (12) | O3vii—B1—O1vi | 116.7 (4) |
O3—Eu—O1iv | 87.70 (12) | O3ix—B2—O3 | 117.6 (5) |
O2ii—Eu—O1iv | 51.94 (10) | O3ix—B2—O1i | 113.1 (2) |
O2iii—Eu—O1iv | 88.41 (10) | O3—B2—O1i | 102.5 (2) |
O1—Eu—O1iv | 85.88 (8) | O3ix—B2—O1viii | 102.5 (2) |
O1i—Eu—O1iv | 63.58 (13) | O3—B2—O1viii | 113.1 (2) |
O2—Eu—O1v | 120.15 (10) | O1i—B2—O1viii | 107.9 (5) |
O2i—Eu—O1v | 141.85 (12) | | |
Symmetry codes: (i) −x+1/2, y, −z+1; (ii) x, −y+1/2, z+1/2; (iii) −x+1/2, −y+1/2, −z+1/2; (iv) x+1/2, −y+1, z; (v) −x, −y+1, −z+1; (vi) x+1/2, y−1/2, z−1/2; (vii) −x+1, −y, −z+1; (viii) x+1, y, z; (ix) −x+3/2, y, −z+1. |
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.