Bis{N-[2-hy­droxy-1,1-bis­(hy­droxy­methyl)eth­yl]glycinato-κ³O,N,O′}iron(II)

In the title compound, [Fe(C₆H₁₂NO₅)₂], the Fe^II ion lies on an inversion center and is coordinated by two N atoms and four O atoms from two tridentate N-[2-hy­droxy-1,1-bis­(hy­droxy­methyl)eth­yl]glycine ligands, forming a slightly distorted octa­hedral coordination environment. In the crystal, O—H...O, O—H...N and weak C—H...O hydrogen bonds link mol­ecules, forming a three-dimensional network.

Key indicators

• Single-crystal X-ray study
• T = 298 K
• Mean [sigma](C-C) = 0.006 Å
• R factor = 0.046
• wR factor = 0.099
• Data-to-parameter ratio = 13.0

checkCIF/PLATON results

No syntax errors found



Alert level C
PLAT414_ALERT_2_C Short Intra D-H..H-X       H2C    ..  H5B     ..       1.96 Ang.
PLAT911_ALERT_3_C Missing # FCF Refl Between THmin & STh/L=  0.600          2 Why ?

Alert level G
PLAT002_ALERT_2_G Number of Distance or Angle Restraints on AtSite          8 Note
PLAT005_ALERT_5_G No _iucr_refine_instructions_details  in the CIF     Please Do !
PLAT066_ALERT_1_G Predicted and Reported Tmin&Tmax Range Identical          ? Check
PLAT128_ALERT_4_G Alternate Setting for Input Space-Group  P21/c        P21/n Note
PLAT232_ALERT_2_G Hirshfeld Test Diff (M-X)  Fe1    --  O3      ..        6.7 su
PLAT232_ALERT_2_G Hirshfeld Test Diff (M-X)  Fe1    --  O5      ..        6.3 su
PLAT232_ALERT_2_G Hirshfeld Test Diff (M-X)  Fe1    --  N1      ..        7.4 su
PLAT793_ALERT_4_G The Model has Chirality at N1      .............          R Verify
PLAT860_ALERT_3_G Number of Least-Squares Restraints .............          4 Note
PLAT912_ALERT_4_G Missing # of FCF Reflections Above STh/L=  0.600          3 Note

   0 ALERT level A = Most likely a serious problem - resolve or explain
   0 ALERT level B = A potentially serious problem, consider carefully
   2 ALERT level C = Check. Ensure it is not caused by an omission or oversight
  10 ALERT level G = General information/check it is not something unexpected

   1 ALERT type 1 CIF construction/syntax error, inconsistent or missing data
   5 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
   3 ALERT type 4 Improvement, methodology, query or suggestion
   1 ALERT type 5 Informative message, check

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S1. Comment

Tripodal alcohols have been used as poly-dentate ligands in combination with paramagnetic 3d transition metal ions leading to the formation of high nuclear clusters since the discovery of the phenomenon of single-molecule magnetism (Brechin, 2005; Murugesu et al., 2005; Pilawa et al., 1998). During our synthesis to form a poly-nuclear cluster using the N-[tris(hydroxymethyl)ethyl]glycine ligand the title compound was fortuitously obtained.

In the title molecule the Fe^II ion is located on an inversion center (Fig. 1). The Fe^II ion is in a slightly distorted octahedral coordination environment formed by two N atoms and four O atoms from two N-[tris(hydroxymethyl)ethyl]glycine ligands. In the crystal, classical O—H···O, O—H···N and weak C—H···O hydrogen bonds (Table 1) connect the molecules into a three-dimensional superamolecular architecture.

Related literature

For background to the applications of tripodal alcohols as single-molecule magnets, see: Pilawa et al. (1998); Brechin (2005); Murugesu et al. (2005).

S2. Experimental

The title compound was synthesized hydrothermally under autogenous pressure. A mixture of FeSO₄ (0.028 g, 0.1 mmol), N-[tris(hydroxymethyl)ethyl]glycine (0.056 g, 0.3 mmol), methanol (3 ml), N,N'-dimethyl formamide (1 ml) and H₂O (2 ml), was stirred for 30 min and then sealed in a 15 ml Teflon-lined stainless container and heated to 358K for 60 h. After cooling to room temperature and subjected to filltration, colorless plates were recovered.

S3. Refinement

Hydrogen atoms bonded to N and O atoms were located in a difference map and refined with distance restraints of O—H = 0.84 (2) and N—H = 0.87 (2) Å. Other H atoms were positioned geometrically and refined using a riding model with C—H = 0.95–0.99 Å.

Computing details

Data collection: SMART (Bruker, 2007); cell refinement: SAINT-Plus (Bruker, 2007); data reduction: SAINT-Plus (Bruker, 2007); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: DIAMOND (Brandenburg & Putz, 2006); software used to prepare material for publication: SHELXTL (Sheldrick, 2008).

Figures

Fig. 1. The molecular structure of the title compound showing 50% displacement ellipsoids. Unlabeled atoms are related by the symmetry operator (-x+1, -y+1, -z+1).

Bis{N-[2-hydroxy-1,1-bis(hydroxymethyl)ethyl]glycinato-κ³O,N,O'}iron(II)

Crystal data

[Fe(C6H12NO5)2]	F(000) = 432
Mr = 412.18	Dx = 1.748 Mg m^−3
Monoclinic, P21/c	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ybc	Cell parameters from 621 reflections
a = 8.8198 (7) Å	θ = 2.9–21.9°
b = 9.0245 (7) Å	µ = 1.02 mm^−1
c = 12.3533 (7) Å	T = 298 K
β = 127.224 (4)°	Sheet, colorless
V = 782.94 (10) Å^3	0.19 × 0.16 × 0.08 mm
Z = 2

Data collection

Bruker SMART CCD diffractometer	1708 independent reflections
Radiation source: fine-focus sealed tube	1230 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.056
multi–scan	θmax = 27.0°, θmin = 2.9°
Absorption correction: multi-scan (SADABS; Bruker, 2007)	h = −11→11
Tmin = 0.829, Tmax = 0.923	k = −11→11
4000 measured reflections	l = −15→15

Refinement

Refinement on F^2	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F^2 > 2σ(F^2)] = 0.046	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.099	H atoms treated by a mixture of independent and constrained refinement
S = 1.04	w = 1/[σ^2(Fo^2) + (0.034P)^2] where P = (Fo^2 + 2Fc^2)/3
1708 reflections	(Δ/σ)max < 0.001
131 parameters	Δρmax = 0.46 e Å^−3
4 restraints	Δρmin = −0.39 e Å^−3

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
Fe1	0.5000	0.5000	0.5000	0.01527 (19)
O1	−0.0265 (4)	0.7341 (3)	0.0516 (3)	0.0347 (7)
O2	0.0173 (4)	0.8369 (3)	0.3530 (3)	0.0355 (7)
O3	0.4719 (4)	0.7180 (3)	0.5354 (3)	0.0323 (7)
O4	0.6437 (4)	0.6393 (3)	0.2600 (3)	0.0356 (7)
O5	0.6619 (3)	0.5743 (3)	0.4408 (2)	0.0283 (6)
N1	0.2766 (4)	0.5686 (3)	0.2962 (3)	0.0209 (6)
C1	0.2121 (5)	0.7215 (4)	0.2983 (3)	0.0190 (8)
C2	0.3608 (5)	0.5508 (4)	0.2233 (3)	0.0237 (8)
H2A	0.2927	0.6132	0.1430	0.028*
H2B	0.3466	0.4488	0.1940	0.028*
C3	0.5700 (5)	0.5920 (4)	0.3128 (4)	0.0243 (8)
C4	0.1289 (5)	0.8101 (4)	0.1682 (4)	0.0276 (9)
H4A	0.0855	0.9056	0.1758	0.033*
H4B	0.2274	0.8276	0.1572	0.033*
C5	0.0626 (5)	0.6982 (4)	0.3222 (4)	0.0269 (8)
H5A	−0.0516	0.6556	0.2416	0.032*
H5B	0.1112	0.6298	0.3971	0.032*
C6	0.3822 (5)	0.8077 (4)	0.4165 (4)	0.0269 (8)
H6A	0.4712	0.8302	0.3973	0.032*
H6B	0.3396	0.9003	0.4299	0.032*
H1A	0.182 (4)	0.506 (3)	0.259 (3)	0.027 (10)*
H3A	0.514 (6)	0.773 (5)	0.605 (3)	0.078 (18)*
H1B	−0.126 (5)	0.787 (5)	0.014 (5)	0.10 (2)*
H2C	0.019 (7)	0.815 (5)	0.421 (4)	0.080 (19)*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Fe1	0.0159 (4)	0.0181 (3)	0.0101 (4)	0.0003 (3)	0.0069 (3)	0.0009 (3)
O1	0.0265 (16)	0.0462 (18)	0.0188 (15)	0.0048 (14)	0.0070 (14)	0.0003 (13)
O2	0.0443 (18)	0.0349 (16)	0.0402 (19)	0.0148 (13)	0.0323 (16)	0.0086 (14)
O3	0.0379 (17)	0.0292 (15)	0.0160 (15)	0.0004 (13)	0.0091 (14)	−0.0017 (12)
O4	0.0293 (15)	0.0513 (18)	0.0283 (16)	0.0014 (13)	0.0185 (14)	0.0135 (13)
O5	0.0234 (14)	0.0396 (15)	0.0174 (14)	0.0003 (12)	0.0100 (12)	0.0048 (12)
N1	0.0203 (16)	0.0195 (16)	0.0220 (17)	−0.0026 (13)	0.0123 (15)	−0.0040 (13)
C1	0.0192 (18)	0.0201 (18)	0.0148 (19)	0.0020 (14)	0.0087 (16)	0.0019 (14)
C2	0.0213 (19)	0.0286 (19)	0.018 (2)	0.0028 (15)	0.0103 (17)	−0.0004 (15)
C3	0.026 (2)	0.0218 (19)	0.024 (2)	0.0015 (16)	0.0141 (18)	0.0035 (16)
C4	0.027 (2)	0.029 (2)	0.022 (2)	0.0025 (17)	0.0123 (19)	0.0029 (17)
C5	0.027 (2)	0.031 (2)	0.025 (2)	0.0050 (17)	0.0166 (19)	0.0038 (17)
C6	0.025 (2)	0.027 (2)	0.023 (2)	−0.0003 (16)	0.0121 (18)	−0.0005 (17)

Geometric parameters (Å, º)

Fe1—O3^i	2.062 (3)	N1—C1	1.498 (4)
Fe1—O3	2.062 (3)	N1—H1A	0.871 (18)
Fe1—O5^i	2.071 (2)	C1—C4	1.527 (4)
Fe1—O5	2.071 (2)	C1—C6	1.529 (5)
Fe1—N1	2.145 (3)	C1—C5	1.531 (4)
Fe1—N1^i	2.145 (3)	C2—C3	1.515 (5)
O1—C4	1.427 (4)	C2—H2A	0.9700
O1—H1B	0.850 (19)	C2—H2B	0.9700
O2—C5	1.433 (4)	C4—H4A	0.9700
O2—H2C	0.854 (19)	C4—H4B	0.9700
O3—C6	1.426 (4)	C5—H5A	0.9700
O3—H3A	0.855 (19)	C5—H5B	0.9700
O4—C3	1.242 (4)	C6—H6A	0.9700
O5—C3	1.277 (4)	C6—H6B	0.9700
N1—C2	1.482 (4)
O3^i—Fe1—O3	180.000 (1)	N1—C1—C5	104.9 (3)
O3^i—Fe1—O5^i	87.88 (10)	C4—C1—C5	110.7 (3)
O3—Fe1—O5^i	92.12 (10)	C6—C1—C5	110.3 (3)
O3^i—Fe1—O5	92.12 (10)	N1—C2—C3	111.5 (3)
O3—Fe1—O5	87.88 (10)	N1—C2—H2A	109.3
O5^i—Fe1—O5	180.0	C3—C2—H2A	109.3
O3^i—Fe1—N1	99.75 (10)	N1—C2—H2B	109.3
O3—Fe1—N1	80.25 (10)	C3—C2—H2B	109.3
O5^i—Fe1—N1	99.68 (10)	H2A—C2—H2B	108.0
O5—Fe1—N1	80.32 (10)	O4—C3—O5	123.4 (3)
O3^i—Fe1—N1^i	80.25 (10)	O4—C3—C2	119.6 (3)
O3—Fe1—N1^i	99.75 (10)	O5—C3—C2	117.0 (3)
O5^i—Fe1—N1^i	80.32 (10)	O1—C4—C1	111.5 (3)
O5—Fe1—N1^i	99.68 (10)	O1—C4—H4A	109.3
N1—Fe1—N1^i	180.000 (1)	C1—C4—H4A	109.3
C4—O1—H1B	109 (4)	O1—C4—H4B	109.3
C5—O2—H2C	102 (3)	C1—C4—H4B	109.3
C6—O3—Fe1	112.7 (2)	H4A—C4—H4B	108.0
C6—O3—H3A	109 (3)	O2—C5—C1	110.0 (3)
Fe1—O3—H3A	137 (3)	O2—C5—H5A	109.7
C3—O5—Fe1	114.9 (2)	C1—C5—H5A	109.7
C2—N1—C1	116.4 (3)	O2—C5—H5B	109.7
C2—N1—Fe1	103.9 (2)	C1—C5—H5B	109.7
C1—N1—Fe1	109.5 (2)	H5A—C5—H5B	108.2
C2—N1—H1A	106 (2)	O3—C6—C1	107.9 (3)
C1—N1—H1A	111 (2)	O3—C6—H6A	110.1
Fe1—N1—H1A	110 (2)	C1—C6—H6A	110.1
N1—C1—C4	114.2 (3)	O3—C6—H6B	110.1
N1—C1—C6	108.8 (3)	C1—C6—H6B	110.1
C4—C1—C6	107.9 (3)	H6A—C6—H6B	108.4
O5^i—Fe1—O3—C6	−120.1 (2)	Fe1—N1—C1—C6	32.2 (3)
O5—Fe1—O3—C6	59.9 (2)	C2—N1—C1—C5	156.7 (3)
N1—Fe1—O3—C6	−20.6 (2)	Fe1—N1—C1—C5	−85.9 (3)
N1^i—Fe1—O3—C6	159.4 (2)	C1—N1—C2—C3	83.5 (4)
O3^i—Fe1—O5—C3	84.2 (2)	Fe1—N1—C2—C3	−37.0 (3)
O3—Fe1—O5—C3	−95.8 (2)	Fe1—O5—C3—O4	178.2 (3)
N1—Fe1—O5—C3	−15.3 (2)	Fe1—O5—C3—C2	−2.4 (4)
N1^i—Fe1—O5—C3	164.7 (2)	N1—C2—C3—O4	−152.0 (3)
O3^i—Fe1—N1—C2	−62.5 (2)	N1—C2—C3—O5	28.6 (4)
O3—Fe1—N1—C2	117.5 (2)	N1—C1—C4—O1	56.5 (4)
O5^i—Fe1—N1—C2	−152.0 (2)	C6—C1—C4—O1	177.6 (3)
O5—Fe1—N1—C2	28.0 (2)	C5—C1—C4—O1	−61.6 (4)
O3^i—Fe1—N1—C1	172.4 (2)	N1—C1—C5—O2	168.6 (3)
O3—Fe1—N1—C1	−7.6 (2)	C4—C1—C5—O2	−67.7 (4)
O5^i—Fe1—N1—C1	82.9 (2)	C6—C1—C5—O2	51.6 (4)
O5—Fe1—N1—C1	−97.1 (2)	Fe1—O3—C6—C1	43.9 (3)
C2—N1—C1—C4	35.4 (4)	N1—C1—C6—O3	−49.6 (3)
Fe1—N1—C1—C4	152.8 (2)	C4—C1—C6—O3	−174.0 (3)
C2—N1—C1—C6	−85.3 (3)	C5—C1—C6—O3	65.0 (3)

Symmetry code: (i) −x+1, −y+1, −z+1.

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
N1—H1A···O2^ii	0.87 (2)	2.10 (2)	2.952 (4)	166 (3)
O3—H3A···O4^iii	0.86 (2)	1.72 (2)	2.562 (4)	167 (5)
O1—H1B···O5^iv	0.85 (2)	1.96 (2)	2.804 (4)	174 (6)
O1—H1B···O4^iv	0.85 (2)	2.59 (5)	3.172 (4)	127 (4)
O2—H2C···O1^iii	0.85 (2)	1.93 (2)	2.779 (4)	170 (5)
C5—H5B···O5^i	0.97	2.56	3.452 (4)	153
C2—H2A···O1	0.97	2.56	3.184 (4)	122

Symmetry codes: (i) −x+1, −y+1, −z+1; (ii) −x, y−1/2, −z+1/2; (iii) x, −y+3/2, z+1/2; (iv) x−1, −y+3/2, z−1/2.