Samarium(III) formate

The title compound, poly[samarium(III)-tri-μ-formato], [Sm(HCO₂)₃]_n, is isostructural with numerous lanthanide formates and comprises a three-dimensional framework assembled from SmO₉ polyhedra and HCO₂⁻ anions. The Sm atom lies on a site of 3m symmetry and is coordinated by nine O atoms in a typical coordination geometry. The formate anions lie on mirror planes.

Key indicators

• Single-crystal X-ray study
• T = 293 K
• Mean [sigma](O-C) = 0.010 Å
• R factor = 0.027
• wR factor = 0.061
• Data-to-parameter ratio = 8.0

checkCIF/PLATON results

No syntax errors found



Alert level C
PLAT062_ALERT_4_C Rescale T(min) & T(max) by .....................       0.96
PLAT164_ALERT_4_C Nr. of Refined C-H H-Atoms in Heavy-At Struct...          1
PLAT199_ALERT_1_C Check the Reported _cell_measurement_temperature        293 K
PLAT200_ALERT_1_C Check the Reported _diffrn_ambient_temperature .        293 K
PLAT764_ALERT_4_C Overcomplete CIF Bond List Detected (Rep/Expd) .       1.36 Ratio

Alert level G
REFLT03_ALERT_4_G Please check that the estimate of the number of Friedel pairs is
            correct. If it is not, please give the correct count in the
            _publ_section_exptl_refinement section of the submitted CIF.
           From the CIF: _diffrn_reflns_theta_max           28.96
           From the CIF: _reflns_number_total                201
           Count of symmetry unique reflns          132
           Completeness (_total/calc)            152.27%
           TEST3: Check Friedels for noncentro structure
           Estimate of Friedel pairs measured        69
           Fraction of Friedel pairs measured     0.523
           Are heavy atom types Z>Si present        yes

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

   2 ALERT type 1 CIF construction/syntax error, inconsistent or missing data
   0 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
   4 ALERT type 4 Improvement, methodology, query or suggestion

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Computing details

Data collection: APEX2 (Bruker, 2005); cell refinement: SAINT (Bruker, 2003); data reduction: SAINT; program(s) used to solve structure: SHELXTL (Sheldrick, 1997); program(s) used to refine structure: SHELXTL; molecular graphics: SHELXTL; software used to prepare material for publication: SHELXTL.

poly[samarium(III)-tri-µ-formato]

Crystal data

[Sm(HCO2)3]	Dx = 3.715 Mg m^−3
Mr = 285.40	Mo Kα radiation, λ = 0.71073 Å
Trigonal, R3m	Cell parameters from 56 reflections
Hall symbol: R 3 -2"	θ = 3.9–28.1°
a = 10.503 (3) Å	µ = 11.47 mm^−1
c = 4.006 (3) Å	T = 293 K
V = 382.7 (3) Å^3	Needle, colourless
Z = 3	0.06 × 0.04 × 0.04 mm
F(000) = 393

Data collection

Bruker APEXII CCD diffractometer	201 independent reflections
Radiation source: fine-focus sealed tube	201 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.052
ω scans	θmax = 29.0°, θmin = 3.9°
Absorption correction: multi-scan (SADABS; Sheldrick, 2003)	h = −13→12
Tmin = 0.546, Tmax = 0.657	k = −13→13
825 measured reflections	l = −5→3

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)] = 0.027	All H-atom parameters refined
wR(F^2) = 0.061	w = 1/[σ^2(Fo^2) + (0.0348P)^2] where P = (Fo^2 + 2Fc^2)/3
S = 1.10	(Δ/σ)max = 0.007
201 reflections	Δρmax = 1.95 e Å^−3
25 parameters	Δρmin = −1.25 e Å^−3
4 restraints	Absolute structure: Flack (1983), 69 Friedel pairs
Primary atom site location: structure-invariant direct methods	Absolute structure parameter: 0.01 (9)

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
Sm1	0.6667	0.3333	0.1791 (5)	0.0113 (3)
O1	0.7991 (5)	0.2009 (5)	0.164 (2)	0.023 (2)
O2	0.9145 (5)	0.0855 (5)	0.343 (2)	0.0163 (18)
C1	0.8459 (7)	0.1541 (7)	0.386 (3)	0.018 (2)
H1	0.830 (2)	0.170 (2)	0.614 (7)	0.021*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Sm1	0.0121 (3)	0.0121 (3)	0.0096 (4)	0.00605 (15)	0.000	0.000
O1	0.030 (4)	0.030 (4)	0.016 (5)	0.021 (4)	−0.0019 (18)	0.0019 (18)
O2	0.015 (3)	0.015 (3)	0.018 (5)	0.007 (4)	−0.0001 (17)	0.0001 (17)
C1	0.020 (4)	0.020 (4)	0.014 (6)	0.012 (5)	0.000 (2)	0.000 (2)

Geometric parameters (Å, º)

Sm1—O1	2.409 (10)	Sm1—O2^viii	2.543 (9)
Sm1—O2^i	2.543 (9)	Sm1—Sm1^ix	4.006 (3)
Sm1—O1^ii	2.409 (10)	Sm1—Sm1^x	4.006 (3)
Sm1—O1^iii	2.409 (10)	O1—C1	1.235 (16)
Sm1—O2^iv	2.529 (9)	O2—C1	1.259 (16)
Sm1—O2^v	2.529 (9)	O2—Sm1^xi	2.529 (9)
Sm1—O2^vi	2.529 (9)	O2—Sm1^xii	2.543 (9)
Sm1—O2^vii	2.543 (9)	C1—H1	0.96 (2)
O1—Sm1—O1^ii	119.93 (2)	O2^vi—Sm1—O2^viii	144.27 (13)
O1—Sm1—O1^iii	119.93 (2)	O2^iv—Sm1—O2^i	144.27 (13)
O1—Sm1—O2^i	126.2 (3)	O2^v—Sm1—O2^i	144.27 (13)
O1—Sm1—O2^vi	129.4 (3)	O2^iv—Sm1—O2^viii	104.3 (3)
O1—Sm1—O2^vii	71.0 (2)	O2^vi—Sm1—O2^i	104.3 (3)
O1—Sm1—O2^v	73.3 (2)	O1—Sm1—Sm1^ix	88.5 (2)
O1—Sm1—O2^viii	71.0 (2)	O1^iii—Sm1—Sm1^ix	88.5 (2)
O1—Sm1—O2^iv	73.3 (2)	O1^ii—Sm1—Sm1^ix	88.5 (2)
O2^iv—Sm1—O2^v	64.4 (3)	O2^iv—Sm1—Sm1^ix	142.0 (2)
O2^vi—Sm1—O2^vii	144.27 (13)	O2^v—Sm1—Sm1^ix	142.0 (2)
O2^v—Sm1—O2^vii	104.3 (3)	O2^vi—Sm1—Sm1^ix	142.0 (2)
O2^vii—Sm1—O2^viii	64.0 (3)	O2^vii—Sm1—Sm1^ix	37.7 (2)
O1^iii—Sm1—O1^ii	119.93 (2)	O2^viii—Sm1—Sm1^ix	37.7 (2)
O1^ii—Sm1—O2^vii	126.2 (3)	O2^i—Sm1—Sm1^ix	37.7 (2)
O1^iii—Sm1—O2^viii	126.2 (3)	O1—Sm1—Sm1^x	91.5 (2)
O1^iii—Sm1—O2^iv	129.4 (3)	O1^iii—Sm1—Sm1^x	91.5 (2)
O1^ii—Sm1—O2^v	129.4 (3)	O1^ii—Sm1—Sm1^x	91.5 (2)
O1^iii—Sm1—O2^vii	71.0 (2)	O2^iv—Sm1—Sm1^x	38.0 (2)
O1^ii—Sm1—O2^viii	71.0 (2)	O2^v—Sm1—Sm1^x	38.0 (2)
O1^iii—Sm1—O2^i	71.0 (2)	O2^vi—Sm1—Sm1^x	38.0 (2)
O1^ii—Sm1—O2^i	71.0 (2)	O2^vii—Sm1—Sm1^x	142.3 (2)
O1^ii—Sm1—O2^iv	73.3 (2)	O2^viii—Sm1—Sm1^x	142.3 (2)
O1^iii—Sm1—O2^v	73.3 (2)	O2^i—Sm1—Sm1^x	142.3 (2)
O1^iii—Sm1—O2^vi	73.3 (2)	Sm1^ix—Sm1—Sm1^x	180.0
O1^ii—Sm1—O2^vi	73.3 (2)	C1—O1—Sm1	132.2 (9)
O2^iv—Sm1—O2^vi	64.4 (3)	C1—O2—Sm1^xi	135.8 (9)
O2^v—Sm1—O2^vi	64.4 (3)	C1—O2—Sm1^xii	119.9 (8)
O2^vii—Sm1—O2^i	64.0 (3)	Sm1^xi—O2—Sm1^xii	104.3 (3)
O2^viii—Sm1—O2^i	64.0 (3)	O1—C1—O2	125.8 (13)
O2^iv—Sm1—O2^vii	144.28 (13)	O1—C1—H1	118 (2)
O2^v—Sm1—O2^viii	144.28 (13)	O2—C1—H1	116 (2)

Symmetry codes: (i) x−1/3, y+1/3, z−2/3; (ii) −y+1, x−y, z; (iii) −x+y+1, −x+1, z; (iv) −x+y+5/3, −x+4/3, z+1/3; (v) −y+2/3, x−y−2/3, z+1/3; (vi) x−1/3, y+1/3, z+1/3; (vii) −y+2/3, x−y−2/3, z−2/3; (viii) −x+y+5/3, −x+4/3, z−2/3; (ix) x, y, z−1; (x) x, y, z+1; (xi) x+1/3, y−1/3, z−1/3; (xii) x+1/3, y−1/3, z+2/3.