Tris(N-acetyl­glycinato-κ²O,O′)triaquaterbium(III)

The title complex, [Tb(C₄H₆NO₃)₃(H₂O)₃], was prepared by reacting terbium carbonate with N-acetyl­glycine in aqueous medium. The Tb^III atom is coordinated by nine O atoms, six of them belonging to the three carboxyl­ate groups of the ligands and three to the water mol­ecules. The molecule lies on a threefold rotation axis.

Key indicators

• Single-crystal X-ray study
• T = 298 K
• Mean [sigma](C-C) = 0.005 Å
• R factor = 0.015
• wR factor = 0.037
• Data-to-parameter ratio = 8.0

checkCIF/PLATON results

No syntax errors found



Alert level C
PLAT164_ALERT_4_C Nr. of Refined C-H H-Atoms in Heavy-At Struct...          5
PLAT222_ALERT_3_C Large Non-Solvent    H     Ueq(max)/Ueq(min) ...       3.21 Ratio
PLAT232_ALERT_2_C Hirshfeld Test Diff (M-X)  Tb1    -   O1      ..       5.72 su
PLAT232_ALERT_2_C Hirshfeld Test Diff (M-X)  Tb1    -   O2      ..       6.70 su
PLAT764_ALERT_4_C Overcomplete CIF Bond List Detected (Rep/Expd) .       1.19 Ratio

Alert level G
REFLT03_ALERT_4_G  WARNING: Large fraction of Friedel related reflns may
                     be needed to determine absolute structure
           From the CIF: _diffrn_reflns_theta_max           27.41
           From the CIF: _reflns_number_total                892
           Count of symmetry unique reflns          719
           Completeness (_total/calc)            124.06%
           TEST3: Check Friedels for noncentro structure
           Estimate of Friedel pairs measured       173
           Fraction of Friedel pairs measured     0.241
           Are heavy atom types Z>Si present        yes
PLAT794_ALERT_5_G Check Predicted Bond Valency for Tb1         (3)       2.97
PLAT860_ALERT_3_G Note: Number of Least-Squares Restraints .......          7

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

   0 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
   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

Rare earth complexes of N-acetylglycine were synthesized and reported to be isostructural and hexagonal (Kamath & Udupa, 1983). However, the detailed structural analysis was not given. The crystal structures of neodymium, europium and erbium complexes of N-acetylglycine have been reported (Zeng & Pan, 1992). The compounds were found to be isostructural and trigonal.

The structure of the title compound contains a Tb^III atom coordinated by six O atoms from three carboxylate groups and three O atoms from water molecules (Fig. 1). The three chelated carboxylate rings are completely staggered. The three Tb—O(water) bonds are also completely staggered with the same angle of 78.5 (1)° between two such bonds (Table 1). The angles O1—C1—O2 are 119.9 (3)°, while the angles subtended at Tb atom by the carboxylate O atoms (O2—Tb1—O1) is 51.97 (7)°. The bond distances between the two carboxylate O atoms and the Tb atom differ by only 0.04 Å. The bond lengths of the two carboxylate O atoms to the C atom differ by only 0.008 Å. The carboxylate group is thus resonance stabilized and functions symmetrically as a bidentate chelate. Apart from the carboxylate group, the bond distances and bond angles of N-acetylglycinate moiety in the title compound are not significantly different from those of free N-acetylglycine and its copper (Udupa and Krebs, 1978), neodymium, europium and erbium complexes (Zeng & Pan, 1992).

The title compound is isostructural with its samarium (Kameshwar et al., 2007), neodymium, europium and erbium analogues (Zeng & Pan, 1992). The coordination geometry of the title compound can be described in terms of a 4,4,4-tricapped triangular prism. The lattice parameters of the samarium and terbium complexes are in line with the well known lanthanide contraction. Interestingly, the terbium complex is found to be triboluminescent and emit green light on striking the crystals with a spatula or a glass rod when observed in dark.

Related literature

For related compounds, see: Kamath & Udupa (1983); Kameshwar et al. (2007); Udupa & Krebs (1978); Zeng & Pan (1992).

S2. Experimental

The title compound was synthesized by adding terbium carbonate (0.397 g, 2.5 mmol) to N-acetylglycine (0.878 g, 7.5 mmol) dissolved in 50 ml water and allowing to react on a steam bath till the carbonate dissolved. A few mg of the carbonate was added to ensure that no unreacted acid was present. The unreacted carbonate was filtered off and the filtrate was evaporated naturally at ambient temperature. The crystals suitable for X-ray diffraction were picked up and dried in air. Analysis, calculated for C₁₂H₂₄N₃O₁₂Tb: C 25.68, H 4.31, N 7.49, Tb 28.32%; found: C 25.26, H 4.33, N 7.11, Tb 28.05%.

S3. Refinement

All H atoms were found in difference Fourier maps and refined isotropically.

Computing details

Data collection: WinAFC (Rigaku/MSC, 2004); cell refinement: WinAFC (Rigaku/MSC, 2004); data reduction: CrystalStructure (Rigaku/MSC, 2004); program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: ORTEP-3 for Windows (Farrugia, 1997); software used to prepare material for publication: WinGX (Farrugia, 1999).

Figures

Fig. 1. The molecular structure of the title compound. Displacement ellipsoids are drawn at the 50% probability level. [Symmetry codes: (i) -x + y, -x, z; (ii) -y, x-y, z.]

Tris(N-acetylglycinato-κ²O,O')triaquaterbium(III)

Crystal data

[Tb(C4H6NO3)3(H2O)3]	Dx = 1.982 Mg m^−3 Dm = 1.983 Mg m^−3 Dm measured by floatation method
Mr = 561.26	Mo Kα radiation, λ = 0.71073 Å
Trigonal, R3	Cell parameters from 25 reflections
Hall symbol: R 3	θ = 12.7–16.8°
a = 16.540 (4) Å	µ = 3.83 mm^−1
c = 5.9554 (12) Å	T = 298 K
V = 1411.0 (6) Å^3	Needle, colourless
Z = 3	0.40 × 0.18 × 0.18 mm
F(000) = 834

Data collection

Rigaku AFC-7S diffractometer	694 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tube	Rint = 0.019
Graphite monochromator	θmax = 27.4°, θmin = 3.7°
ω–2θ scans	h = −21→18
Absorption correction: ψ scan (North et al., 1968)	k = 0→21
Tmin = 0.310, Tmax = 0.515	l = −4→7
1384 measured reflections	3 standard reflections every 150 reflections
892 independent reflections	intensity decay: 1.8%

Refinement

Refinement on F^2	Secondary atom site location: difference Fourier map
Least-squares matrix: full	Hydrogen site location: difference Fourier map
R[F^2 > 2σ(F^2)] = 0.015	All H-atom parameters refined
wR(F^2) = 0.037	w = 1/[σ^2(Fo^2) + (0.0321P)^2] where P = (Fo^2 + 2Fc^2)/3
S = 1.01	(Δ/σ)max < 0.001
892 reflections	Δρmax = 0.37 e Å^−3
111 parameters	Δρmin = −0.76 e Å^−3
7 restraints	Absolute structure: Flack (1983); 172 Friedel pairs
Primary atom site location: structure-invariant direct methods	Absolute structure parameter: −0.013 (11)

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Ų)

	x	y	z	Uiso*/Ueq
C2	0.2261 (2)	0.2052 (2)	0.2356 (5)	0.0230 (6)
N2	0.25512 (18)	0.1769 (2)	0.0361 (5)	0.0238 (5)
C3	0.3229 (2)	0.1546 (2)	0.0448 (5)	0.0242 (6)
O3	0.36586 (17)	0.1634 (2)	0.2220 (4)	0.0336 (6)
C4	0.3410 (3)	0.1165 (3)	−0.1642 (7)	0.0343 (8)
O4	−0.1128 (2)	−0.0928 (2)	0.9043 (4)	0.0257 (5)
H1	0.223 (3)	0.169 (3)	−0.099 (9)	0.039 (12)*
H2B	0.280 (3)	0.247 (3)	0.335 (7)	0.028 (10)*
H2A	0.190 (3)	0.234 (3)	0.202 (8)	0.041 (12)*
H4A	0.314 (4)	0.129 (4)	−0.301 (9)	0.058 (15)*
H4C	0.404 (5)	0.140 (4)	−0.185 (11)	0.08 (2)*
H4B	0.314 (4)	0.051 (4)	−0.169 (10)	0.065 (18)*
H2W	−0.0975	−0.1118	1.0376	0.048 (13)*
H1W	−0.1653	−0.1002	0.8540	0.09 (3)*
Tb1	0.0000	0.0000	0.6338	0.01496 (6)
O1	0.11955 (16)	0.04238 (17)	0.3289 (4)	0.0231 (4)
O2	0.14810 (16)	0.14866 (16)	0.5830 (4)	0.0258 (5)
C1	0.1632 (3)	0.1268 (2)	0.3916 (5)	0.0173 (5)

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
C2	0.0198 (13)	0.0239 (14)	0.0214 (15)	0.0080 (12)	0.0025 (12)	0.0027 (12)
N2	0.0176 (11)	0.0309 (14)	0.0180 (12)	0.0084 (11)	0.0003 (10)	0.0017 (11)
C3	0.0170 (13)	0.0237 (15)	0.0241 (15)	0.0043 (12)	0.0038 (12)	0.0040 (12)
O3	0.0252 (12)	0.0481 (15)	0.0273 (13)	0.0183 (11)	−0.0041 (10)	0.0008 (12)
C4	0.0286 (17)	0.038 (2)	0.032 (2)	0.0134 (15)	0.0061 (15)	−0.0041 (16)
O4	0.0211 (13)	0.0325 (14)	0.0227 (12)	0.0126 (12)	0.0009 (11)	0.0103 (11)
Tb1	0.01651 (7)	0.01651 (7)	0.01186 (9)	0.00826 (3)	0.000	0.000
O1	0.0244 (11)	0.0221 (11)	0.0204 (10)	0.0099 (9)	0.0020 (9)	−0.0010 (9)
O2	0.0280 (11)	0.0260 (11)	0.0175 (11)	0.0092 (9)	0.0041 (9)	−0.0025 (9)
C1	0.0131 (14)	0.0221 (15)	0.0157 (13)	0.0081 (13)	−0.0014 (12)	0.0017 (12)

Geometric parameters (Å, º)

C2—N2	1.445 (4)	Tb1—O4^i	2.359 (3)
C2—C1	1.509 (4)	Tb1—O4^ii	2.359 (3)
C2—H2B	1.00 (4)	Tb1—O2^i	2.473 (2)
C2—H2A	0.95 (5)	Tb1—O2^ii	2.473 (2)
N2—C3	1.345 (4)	Tb1—O2	2.473 (2)
N2—H1	0.94 (5)	Tb1—O1^i	2.513 (2)
C3—O3	1.239 (4)	Tb1—O1	2.513 (2)
C3—C4	1.492 (5)	Tb1—O1^ii	2.513 (2)
C4—H4A	1.00 (6)	Tb1—C1^i	2.847 (3)
C4—H4C	0.92 (7)	Tb1—C1^ii	2.847 (3)
C4—H4B	0.94 (6)	Tb1—C1	2.847 (3)
O4—H2W	0.934	O1—C1	1.266 (4)
O4—H1W	0.868	O2—C1	1.258 (4)
Tb1—O4	2.359 (3)
N2—C2—C1	115.2 (3)	O1^i—Tb1—O1	73.53 (8)
N2—C2—H2B	113 (2)	O4^i—Tb1—O1^ii	93.22 (9)
C1—C2—H2B	103 (2)	O4^ii—Tb1—O1^ii	158.57 (8)
N2—C2—H2A	113 (3)	O4—Tb1—O1^ii	119.55 (8)
C1—C2—H2A	103 (3)	O2^i—Tb1—O1^ii	123.70 (7)
H2B—C2—H2A	109 (4)	O2^ii—Tb1—O1^ii	51.97 (7)
C3—N2—C2	121.0 (3)	O2—Tb1—O1^ii	78.21 (8)
C3—N2—H1	119 (3)	O1^i—Tb1—O1^ii	73.53 (8)
C2—N2—H1	120 (3)	O1—Tb1—O1^ii	73.53 (8)
O3—C3—N2	120.6 (3)	O4^i—Tb1—C1^i	167.21 (8)
O3—C3—C4	122.4 (3)	O4^ii—Tb1—C1^i	93.26 (10)
N2—C3—C4	117.1 (3)	O4—Tb1—C1^i	90.32 (11)
C3—C4—H4A	113 (3)	O2^i—Tb1—C1^i	26.15 (8)
C3—C4—H4C	111 (4)	O2^ii—Tb1—C1^i	101.31 (9)
H4A—C4—H4C	109 (5)	O2—Tb1—C1^i	121.02 (9)
C3—C4—H4B	115 (4)	O1^i—Tb1—C1^i	26.40 (8)
H4A—C4—H4B	102 (5)	O1—Tb1—C1^i	70.24 (9)
H4C—C4—H4B	106 (5)	O1^ii—Tb1—C1^i	97.76 (8)
Tb1—O4—H2W	122.7	O4^i—Tb1—C1^ii	90.32 (11)
Tb1—O4—H1W	105.44	O4^ii—Tb1—C1^ii	167.21 (8)
H2W—O4—H1W	131.8	O4—Tb1—C1^ii	93.26 (10)
O4^i—Tb1—O4^ii	78.52 (11)	O2^i—Tb1—C1^ii	121.02 (9)
O4^i—Tb1—O4	78.52 (11)	O2^ii—Tb1—C1^ii	26.15 (8)
O4^ii—Tb1—O4	78.52 (11)	O2—Tb1—C1^ii	101.31 (9)
O4^i—Tb1—O2^i	142.98 (9)	O1^i—Tb1—C1^ii	70.24 (9)
O4^ii—Tb1—O2^i	67.66 (8)	O1—Tb1—C1^ii	97.76 (8)
O4—Tb1—O2^i	80.36 (9)	O1^ii—Tb1—C1^ii	26.40 (8)
O4^i—Tb1—O2^ii	80.36 (9)	C1^i—Tb1—C1^ii	96.60 (9)
O4^ii—Tb1—O2^ii	142.98 (9)	O4^i—Tb1—C1	93.26 (10)
O4—Tb1—O2^ii	67.66 (8)	O4^ii—Tb1—C1	90.32 (11)
O2^i—Tb1—O2^ii	118.52 (2)	O4—Tb1—C1	167.21 (8)
O4^i—Tb1—O2	67.66 (8)	O2^i—Tb1—C1	101.31 (9)
O4^ii—Tb1—O2	80.36 (9)	O2^ii—Tb1—C1	121.02 (9)
O4—Tb1—O2	142.98 (9)	O2—Tb1—C1	26.15 (8)
O2^i—Tb1—O2	118.52 (2)	O1^i—Tb1—C1	97.76 (8)
O2^ii—Tb1—O2	118.52 (2)	O1—Tb1—C1	26.40 (8)
O4^i—Tb1—O1^i	158.57 (8)	O1^ii—Tb1—C1	70.24 (9)
O4^ii—Tb1—O1^i	119.55 (8)	C1^i—Tb1—C1	96.60 (9)
O4—Tb1—O1^i	93.22 (9)	C1^ii—Tb1—C1	96.60 (9)
O2^i—Tb1—O1^i	51.97 (7)	C1—O1—Tb1	91.7 (2)
O2^ii—Tb1—O1^i	78.21 (8)	C1—O2—Tb1	93.8 (2)
O2—Tb1—O1^i	123.70 (8)	O2—C1—O1	119.9 (3)
O4^i—Tb1—O1	119.55 (8)	O2—C1—C2	117.5 (3)
O4^ii—Tb1—O1	93.22 (9)	O1—C1—C2	122.3 (3)
O4—Tb1—O1	158.57 (8)	O2—C1—Tb1	60.08 (17)
O2^i—Tb1—O1	78.21 (8)	O1—C1—Tb1	61.90 (18)
O2^ii—Tb1—O1	123.70 (7)	C2—C1—Tb1	159.6 (2)
O2—Tb1—O1	51.97 (7)
C1—C2—N2—C3	−77.5 (4)	O4^ii—Tb1—C1—O2	−67.0 (2)
C2—N2—C3—O3	−4.4 (5)	O4—Tb1—C1—O2	−37.9 (5)
C2—N2—C3—C4	173.7 (3)	O2^i—Tb1—C1—O2	−134.22 (18)
O4^i—Tb1—O1—C1	−5.6 (3)	O2^ii—Tb1—C1—O2	92.27 (16)
O4^ii—Tb1—O1—C1	−84.2 (2)	O1^i—Tb1—C1—O2	173.14 (19)
O4—Tb1—O1—C1	−150.5 (2)	O1—Tb1—C1—O2	−163.6 (3)
O2^i—Tb1—O1—C1	−150.6 (2)	O1^ii—Tb1—C1—O2	103.8 (2)
O2^ii—Tb1—O1—C1	92.8 (2)	C1^i—Tb1—C1—O2	−160.3 (2)
O2—Tb1—O1—C1	−9.12 (19)	C1^ii—Tb1—C1—O2	102.3 (2)
O1^i—Tb1—O1—C1	155.9 (2)	O4^i—Tb1—C1—O1	175.1 (2)
O1^ii—Tb1—O1—C1	78.6 (2)	O4^ii—Tb1—C1—O1	96.60 (19)
C1^i—Tb1—O1—C1	−176.5 (2)	O4—Tb1—C1—O1	125.6 (4)
C1^ii—Tb1—O1—C1	89.20 (15)	O2^i—Tb1—C1—O1	29.3 (2)
O4^i—Tb1—O2—C1	−167.5 (2)	O2^ii—Tb1—C1—O1	−104.2 (2)
O4^ii—Tb1—O2—C1	111.0 (2)	O2—Tb1—C1—O1	163.6 (3)
O4—Tb1—O2—C1	166.95 (19)	O1^i—Tb1—C1—O1	−23.3 (2)
O2^i—Tb1—O2—C1	53.1 (2)	O1^ii—Tb1—C1—O1	−92.6 (2)
O2^ii—Tb1—O2—C1	−102.93 (19)	C1^i—Tb1—C1—O1	3.3 (2)
O1^i—Tb1—O2—C1	−8.2 (2)	C1^ii—Tb1—C1—O1	−94.18 (15)
O1—Tb1—O2—C1	9.20 (19)	O4^i—Tb1—C1—C2	−77.4 (6)
O1^ii—Tb1—O2—C1	−69.0 (2)	O4^ii—Tb1—C1—C2	−155.9 (6)
C1^i—Tb1—O2—C1	23.0 (2)	O4—Tb1—C1—C2	−126.9 (6)
C1^ii—Tb1—O2—C1	−81.9 (2)	O2^i—Tb1—C1—C2	136.8 (6)
Tb1—O2—C1—O1	−16.7 (4)	O2^ii—Tb1—C1—C2	3.3 (7)
Tb1—O2—C1—C2	156.9 (3)	O2—Tb1—C1—C2	−88.9 (7)
Tb1—O1—C1—O2	16.4 (3)	O1^i—Tb1—C1—C2	84.2 (6)
Tb1—O1—C1—C2	−156.8 (3)	O1—Tb1—C1—C2	107.5 (7)
N2—C2—C1—O2	168.9 (3)	O1^ii—Tb1—C1—C2	14.9 (6)
N2—C2—C1—O1	−17.6 (5)	C1^i—Tb1—C1—C2	110.8 (6)
N2—C2—C1—Tb1	−113.4 (6)	C1^ii—Tb1—C1—C2	13.3 (7)
O4^i—Tb1—C1—O2	11.56 (19)

Symmetry codes: (i) −x+y, −x, z; (ii) −y, x−y, z.