Hexaamminecobalt(III) aquabis(nitrilotriacetato-[kappa]⁴N,O,O',O'')gadolinate(III) octahydrate

Crystals of the title compound, [Co(NH₃)₆][Gd(C₆H₆NO₆)₂(H₂O)]·8H₂O, were synthesized in and collected from aqueous solution. The hexaamminecobalt(III) cation has the expected octahedral geometry, while the Gd coordination sphere has the geometry of a tricapped trigonal prism, with the two nitrilo­tri­acetate N atoms and one water mol­ecule occupying the capping positions.

S1. Comment

Gadolinium complexes have found widespread use as contrast agents in magnetic resonance imaging (MRI), with an estimate of over 30 tonnes of Gd having been administered since the first commercial Gd contrast agent was approved by the US Food and Drug Administration (FDA) for use in humans in 1988 (Caravan et al., 1999; Lauffer, 1987). Each of these compounds is composed of an octadentate chelating ligand and one coordinating water molecule, forming a nine-coordinate complex. A search of Version 5.22 of the Cambridge Structural Database (Allen & Kennard, 1993) identified only 298 structures of Gd complexes. Our synthesis of Gd-nitrilotriacetate complexes (Gd-NTA) is part of an effort to extend this database, and the structure of the title Gd-NTA complex, (I), is presented here. \sch

A bis(NTA)gadolinate complex with a [Gd(H₂O)_x]⁺³ counterion was previously synthesized by Parrish et al. (1998) from a 1:1 mixture of gadolinium chloride and NTA. The compound was found to have a high degree of disorder, in particular in the aqua-Gd cation, as well as either an inconveniently long cell length, c = 80.83 (2) Å, or a twinning problem.

The synthesis of (I) was undertaken in order to try to eliminate some of the problems in the original structure. Hexaamminecobalt(III) chloride was used to precipitate the anionic complex, thus eliminating the largest single source of disorder. Orange crystals of (I) formed from an aqueous 2:1 mole ratio mixture of NTA with hexaamminecobalt(III) chloride and an excess of gadolinium(III) chloride (the hygroscopic nature of the starting material precludes exact molar quantification).

Complex (I) (Fig. 1) is nine-coordinate, as are 43% of the previously reported complexes (Allen & Kennard, 1993) and 100% of FDA-approved MRI contrast agents (Caravan et al., 1999). The complex is a tricapped trigonal prism (Fig. 2), as is common for nine-coordinate complexes (Guggenberger & Muetterties, 1976). Bond distances and angles for the coordination sphere of (I) are given in Table 1. An O atom from the coordinated water molecule and the two NTA N atoms occupy the capping positions. Of the eight noncoordinated water molecules, six form one hydrogen bond with carboxyl groups, while the remaining two each form hydrogen bonds with two separate carboxyl groups. The locations of the H atoms of the water molecules were not experimentally observed and were not included. There appeared to be some disorder in the waters of hydration, but it was not possible to separate individual positions within the electron density.

The Co coordination sphere in (I) is octahedral, with Co—N distances in the range 1.962 (6)–1.981 (7) Å, and N—Co—N angles in the range 88.5 (3)–91.5 (3)° for cis N atoms and 178.8 (3)–179.4 (3)° for trans N atoms.

S2. Experimental

Hexaamminecobalt(III) chloride (0.1652 g, 0.6176 mmol), the disodium salt of nitrilotriacetic acid (0.2816 g, 1.198 mmol) and gadolinium(III) chloride (approximately 1 mmol) were dissolved in water (approximately 50 ml; gadolinium chloride is hygroscopic so an excess was used to ensure that NTA was the limiting reagent). The solvent was allowed to evaporate slowly over the course of a week, resulting in the formation of orange plates. A 26.1% yield (0.1338 g) of (I) was recovered from the reaction mixture. Elemental analysis was in agreement with crystallographic data (expected for C₁₂H₄₈CoGdN₈O₂₁: C 16.82, H 5.65, N 13.08%; found: C 16.80, H 5.92, N 13.07%). Attempts to determine a melting point failed, as the compound was found to decompose with a visible loss of liquid, presumably water, at approximately 373 K, leaving a red solid residue. The resulting solid was found to have low solubility in water, but was not further characterized.

S3. Refinement

H atoms were treated as riding, with N—H distances of 0.89 Å and C—H distances of 0.97 Å. Is this added text OK? The highest peak in the difference map is 0.76 Å and the deepest hole 0.63 Å from Gd.

Computing details

Data collection: Please provide missing information; cell refinement: Please provide missing information; data reduction: Please provide missing information; program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: Please provide missing information; software used to prepare material for publication: Please provide missing information.

Figures

	Fig. 1. A view of the structure of (I), showing the discrete anion and cation pair. Displacement ellipsoids are drawn at the 50% probability level and H atoms and waters of hydration have been omitted for clarity.
	Fig. 2. The coordination sphere of the gadolinate anion, showing the tricapped trigonal prism geometry with atoms N7, N8 and O13 occupying the capping positions. Displacement ellipsoids are drawn at the 50% probability level.

Hexaamminecobalt(III) aquabis(nitrilotriacetato-κ⁴N,O,O',O'')gadolinate(III) octahydrate

Crystal data

[Co(NH3)6][Gd(C6H6NO6)2(H2O)]·8H2O	F(000) = 1740
Mr = 856.76	Dx = 1.814 Mg m^−3 Dm = 1.77 (3) Mg m^−3 Dm measured by flotation in what
Monoclinic, P21/n	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2yn	Cell parameters from 28 reflections
a = 11.760 (2) Å	θ = 1.5–27.5°
b = 20.625 (4) Å	µ = 2.72 mm^−1
c = 14.109 (3) Å	T = 293 K
β = 113.55 (3)°	Plate, light orange
V = 3137.1 (13) Å^3	0.40 × 0.29 × 0.20 mm
Z = 4

Data collection

Bruker R3 diffractometer	5526 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tube	Rint = 0.056
Graphite monochromator	θmax = 27.6°, θmin = 1.9°
θ/2θ scans	h = 0→15
Absorption correction: ψ scan (SHELXTL-Plus; Sheldrick, 1990)	k = 0→26
Tmin = 0.361, Tmax = 0.581	l = −18→16
7452 measured reflections	3 standard reflections every 50 reflections
7126 independent reflections	intensity decay: 16%

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)] = 0.058	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.172	H-atom parameters constrained
S = 1.12	w = 1/[σ^2(Fo^2) + (0.0968P)^2 + 15.8892P] where P = (Fo^2 + 2Fc^2)/3
7126 reflections	(Δ/σ)max = 0.028
394 parameters	Δρmax = 3.76 e Å^−3
0 restraints	Δρmin = −4.27 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
Gd	0.26700 (3)	0.172832 (15)	0.73769 (2)	0.02221 (12)
Co	0.51856 (8)	0.24710 (5)	0.48801 (7)	0.0265 (2)
N1	0.6486 (6)	0.2045 (3)	0.4542 (5)	0.0384 (14)
H1C	0.6137	0.1847	0.3932	0.058*
H1D	0.6886	0.1755	0.5028	0.058*
H1E	0.7021	0.2342	0.4513	0.058*
N2	0.6452 (6)	0.2717 (4)	0.6241 (4)	0.0401 (16)
H2A	0.6284	0.3110	0.6410	0.060*
H2B	0.7196	0.2719	0.6214	0.060*
H2C	0.6449	0.2432	0.6714	0.060*
N3	0.4859 (7)	0.1645 (3)	0.5434 (5)	0.0390 (15)
H3C	0.4179	0.1463	0.4970	0.059*
H3D	0.4750	0.1722	0.6013	0.059*
H3E	0.5502	0.1380	0.5570	0.059*
N4	0.3911 (6)	0.2231 (3)	0.3526 (4)	0.0334 (13)
H4A	0.3174	0.2217	0.3564	0.050*
H4B	0.4088	0.1844	0.3343	0.050*
H4C	0.3894	0.2525	0.3058	0.050*
N5	0.5498 (6)	0.3292 (3)	0.4297 (5)	0.0356 (14)
H5C	0.5802	0.3204	0.3826	0.053*
H5D	0.6042	0.3530	0.4800	0.053*
H5E	0.4790	0.3510	0.4002	0.053*
N6	0.3896 (6)	0.2915 (3)	0.5209 (5)	0.0362 (14)
H6A	0.3526	0.3216	0.4733	0.054*
H6B	0.4246	0.3103	0.5827	0.054*
H6C	0.3336	0.2627	0.5216	0.054*
N7	0.4558 (5)	0.1095 (3)	0.8829 (4)	0.0259 (11)
N8	0.0772 (6)	0.1115 (3)	0.5918 (4)	0.0302 (12)
O1	0.1713 (6)	0.1759 (3)	0.3970 (5)	0.0516 (17)
O2	0.2236 (5)	0.2017 (3)	0.5610 (4)	0.0338 (11)
O3	−0.1298 (5)	0.1857 (3)	0.6843 (5)	0.0469 (15)
O4	0.0735 (5)	0.2057 (3)	0.7313 (4)	0.0428 (14)
O5	0.0664 (8)	−0.0032 (3)	0.7815 (5)	0.070 (2)
O6	0.1849 (5)	0.0833 (3)	0.7989 (4)	0.0371 (12)
O7	0.4432 (7)	−0.0114 (3)	0.6916 (5)	0.0570 (18)
O8	0.3477 (5)	0.0837 (3)	0.6740 (4)	0.0372 (12)
O9	0.6636 (6)	0.1816 (3)	0.7913 (5)	0.0461 (15)
O10	0.4655 (5)	0.2065 (3)	0.7448 (4)	0.0359 (12)
O11	0.3597 (7)	0.1730 (4)	1.0774 (5)	0.059 (2)
O12	0.3127 (5)	0.2016 (3)	0.9149 (4)	0.0348 (11)
O13	0.2686 (6)	0.2916 (3)	0.7369 (5)	0.0503 (16)
O14	0.4657 (6)	0.3627 (3)	0.7253 (5)	0.0507 (15)
O15	0.5680 (7)	0.1379 (3)	0.2483 (5)	0.0534 (16)
O16	0.3346 (9)	0.4164 (5)	0.3537 (9)	0.100 (3)
O17	0.3633 (14)	0.0723 (7)	0.3431 (16)	0.177 (8)
O18	0.8064 (17)	0.0099 (9)	0.0034 (10)	0.185 (7)
O19	0.814 (2)	0.0031 (13)	0.704 (2)	0.280 (12)
O20	0.167 (2)	0.0810 (8)	0.1280 (16)	0.213 (9)
O21	0.3233 (14)	0.9454 (6)	0.4873 (9)	0.134 (5)
C1	0.1000 (7)	0.1073 (4)	0.4970 (5)	0.0324 (15)
H1A	0.0215	0.1030	0.4380	0.039*
H1B	0.1489	0.0689	0.5000	0.039*
C2	0.1684 (7)	0.1669 (4)	0.4825 (5)	0.0321 (15)
C3	−0.0332 (7)	0.1521 (4)	0.5722 (5)	0.0339 (15)
H3A	−0.1069	0.1255	0.5413	0.041*
H3B	−0.0369	0.1857	0.5230	0.041*
C4	−0.0331 (7)	0.1840 (3)	0.6710 (5)	0.0286 (14)
C5	0.0605 (8)	0.0477 (4)	0.6287 (6)	0.0385 (17)
H5A	0.1035	0.0159	0.6044	0.046*
H5B	−0.0271	0.0369	0.5987	0.046*
C6	0.1079 (8)	0.0427 (4)	0.7460 (6)	0.0356 (16)
C7	0.4687 (8)	0.0453 (4)	0.8448 (6)	0.0413 (18)
H7A	0.4265	0.0140	0.8709	0.050*
H7B	0.5559	0.0338	0.8728	0.050*
C8	0.4172 (7)	0.0396 (4)	0.7274 (6)	0.0347 (16)
C9	0.5671 (7)	0.1499 (4)	0.9033 (5)	0.0348 (16)
H9A	0.6407	0.1232	0.9339	0.042*
H9B	0.5712	0.1836	0.9526	0.042*
C10	0.5660 (6)	0.1812 (4)	0.8054 (5)	0.0301 (15)
C11	0.4320 (7)	0.1053 (4)	0.9774 (5)	0.0315 (15)
H11A	0.5103	0.1006	1.0366	0.038*
H11B	0.3824	0.0671	0.9737	0.038*
C12	0.3648 (7)	0.1649 (4)	0.9923 (6)	0.0338 (16)

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Gd	0.02181 (18)	0.02431 (18)	0.02094 (17)	−0.00025 (12)	0.00898 (12)	0.00006 (12)
Co	0.0214 (4)	0.0391 (5)	0.0193 (4)	−0.0014 (4)	0.0086 (3)	0.0038 (3)
N1	0.037 (3)	0.041 (4)	0.040 (3)	−0.002 (3)	0.018 (3)	0.004 (3)
N2	0.032 (3)	0.062 (4)	0.021 (3)	−0.005 (3)	0.004 (2)	0.004 (3)
N3	0.043 (4)	0.044 (4)	0.031 (3)	−0.002 (3)	0.016 (3)	0.009 (3)
N4	0.030 (3)	0.043 (3)	0.025 (3)	−0.004 (3)	0.009 (2)	0.001 (3)
N5	0.036 (3)	0.045 (4)	0.033 (3)	−0.002 (3)	0.022 (3)	0.006 (3)
N6	0.026 (3)	0.049 (4)	0.038 (3)	−0.003 (3)	0.018 (3)	0.001 (3)
N7	0.029 (3)	0.029 (3)	0.020 (2)	0.001 (2)	0.011 (2)	0.001 (2)
N8	0.032 (3)	0.034 (3)	0.028 (3)	−0.005 (2)	0.015 (2)	0.000 (2)
O1	0.052 (4)	0.077 (5)	0.030 (3)	−0.020 (3)	0.020 (3)	0.000 (3)
O2	0.033 (3)	0.040 (3)	0.024 (2)	−0.009 (2)	0.008 (2)	0.000 (2)
O3	0.031 (3)	0.068 (4)	0.045 (3)	−0.006 (3)	0.020 (3)	−0.017 (3)
O4	0.033 (3)	0.080 (4)	0.020 (2)	−0.021 (3)	0.016 (2)	−0.019 (3)
O5	0.096 (6)	0.054 (4)	0.047 (4)	−0.047 (4)	0.016 (4)	0.004 (3)
O6	0.042 (3)	0.035 (3)	0.033 (3)	−0.012 (2)	0.015 (2)	0.006 (2)
O7	0.087 (5)	0.033 (3)	0.051 (4)	0.020 (3)	0.027 (4)	−0.003 (3)
O8	0.044 (3)	0.034 (3)	0.031 (3)	0.011 (2)	0.013 (2)	−0.002 (2)
O9	0.037 (3)	0.061 (4)	0.049 (3)	0.007 (3)	0.027 (3)	0.017 (3)
O10	0.027 (3)	0.048 (3)	0.035 (3)	−0.008 (2)	0.015 (2)	0.012 (2)
O11	0.055 (4)	0.097 (6)	0.030 (3)	0.027 (4)	0.021 (3)	0.003 (3)
O12	0.033 (3)	0.042 (3)	0.027 (2)	0.010 (2)	0.010 (2)	−0.004 (2)
O13	0.051 (4)	0.022 (3)	0.081 (5)	−0.003 (2)	0.030 (3)	−0.003 (3)
O14	0.059 (4)	0.044 (3)	0.041 (3)	0.002 (3)	0.010 (3)	−0.002 (3)
O15	0.061 (4)	0.042 (3)	0.046 (3)	−0.003 (3)	0.009 (3)	0.005 (3)
O16	0.089 (7)	0.088 (7)	0.117 (8)	0.010 (5)	0.036 (6)	−0.018 (6)
O17	0.134 (11)	0.120 (11)	0.31 (2)	0.001 (9)	0.122 (14)	−0.065 (12)
O18	0.218 (17)	0.240 (18)	0.074 (7)	0.018 (15)	0.034 (9)	0.057 (10)
O19	0.23 (2)	0.26 (3)	0.31 (3)	−0.01 (2)	0.06 (2)	0.08 (2)
O20	0.34 (3)	0.110 (12)	0.205 (19)	0.059 (14)	0.120 (19)	0.023 (11)
O21	0.167 (12)	0.124 (10)	0.083 (7)	−0.007 (9)	0.021 (8)	−0.017 (7)
C1	0.036 (4)	0.036 (4)	0.026 (3)	−0.009 (3)	0.013 (3)	−0.006 (3)
C2	0.025 (3)	0.043 (4)	0.025 (3)	−0.004 (3)	0.007 (3)	0.003 (3)
C3	0.026 (3)	0.044 (4)	0.027 (3)	0.002 (3)	0.006 (3)	0.000 (3)
C4	0.029 (3)	0.033 (4)	0.024 (3)	0.005 (3)	0.011 (3)	0.003 (3)
C5	0.049 (5)	0.031 (4)	0.034 (4)	−0.011 (3)	0.014 (3)	−0.002 (3)
C6	0.043 (4)	0.029 (4)	0.034 (4)	−0.002 (3)	0.015 (3)	0.003 (3)
C7	0.051 (5)	0.035 (4)	0.036 (4)	0.013 (3)	0.015 (4)	0.004 (3)
C8	0.039 (4)	0.029 (3)	0.037 (4)	0.001 (3)	0.016 (3)	0.003 (3)
C9	0.027 (3)	0.048 (4)	0.025 (3)	−0.004 (3)	0.007 (3)	0.007 (3)
C10	0.020 (3)	0.043 (4)	0.030 (3)	−0.001 (3)	0.013 (3)	0.005 (3)
C11	0.032 (3)	0.035 (4)	0.028 (3)	0.008 (3)	0.012 (3)	0.008 (3)
C12	0.029 (3)	0.048 (4)	0.024 (3)	0.003 (3)	0.010 (3)	0.000 (3)

Geometric parameters (Å, º)

Gd—O4	2.342 (6)	N7—C9	1.480 (9)
Gd—O10	2.399 (5)	N8—C5	1.458 (9)
Gd—O6	2.399 (5)	N8—C1	1.468 (9)
Gd—O8	2.403 (5)	N8—C3	1.474 (9)
Gd—O2	2.411 (5)	O1—C2	1.233 (9)
Gd—O12	2.412 (5)	O2—C2	1.261 (9)
Gd—O13	2.449 (6)	O3—C4	1.224 (9)
Gd—N8	2.674 (6)	O4—C4	1.282 (9)
Gd—N7	2.682 (6)	O5—C6	1.257 (10)
Co—N4	1.962 (6)	O6—C6	1.240 (9)
Co—N2	1.969 (6)	O7—C8	1.257 (9)
Co—N3	1.975 (6)	O8—C8	1.254 (9)
Co—N5	1.979 (6)	O9—C10	1.241 (9)
Co—N6	1.980 (6)	O10—C10	1.262 (9)
Co—N1	1.981 (7)	O11—C12	1.238 (9)
N1—H1C	0.8900	O12—C12	1.268 (9)
N1—H1D	0.8900	C1—C2	1.527 (10)
N1—H1E	0.8900	C1—H1A	0.9700
N2—H2A	0.8900	C1—H1B	0.9700
N2—H2B	0.8900	C3—C4	1.541 (10)
N2—H2C	0.8900	C3—H3A	0.9700
N3—H3C	0.8900	C3—H3B	0.9700
N3—H3D	0.8900	C5—C6	1.525 (10)
N3—H3E	0.8900	C5—H5A	0.9700
N4—H4A	0.8900	C5—H5B	0.9700
N4—H4B	0.8900	C7—C8	1.524 (11)
N4—H4C	0.8900	C7—H7A	0.9700
N5—H5C	0.8900	C7—H7B	0.9700
N5—H5D	0.8900	C9—C10	1.520 (10)
N5—H5E	0.8900	C9—H9A	0.9700
N6—H6A	0.8900	C9—H9B	0.9700
N6—H6B	0.8900	C11—C12	1.520 (10)
N6—H6C	0.8900	C11—H11A	0.9700
N7—C7	1.461 (9)	C11—H11B	0.9700
N7—C11	1.470 (9)
O4—Gd—O10	146.3 (2)	H5D—N5—H5E	109.5
O4—Gd—O6	73.3 (2)	Co—N6—H6A	109.5
O10—Gd—O6	137.14 (19)	Co—N6—H6B	109.5
O4—Gd—O8	136.9 (2)	H6A—N6—H6B	109.5
O10—Gd—O8	73.4 (2)	Co—N6—H6C	109.5
O6—Gd—O8	79.8 (2)	H6A—N6—H6C	109.5
O4—Gd—O2	95.01 (18)	H6B—N6—H6C	109.5
O10—Gd—O2	76.83 (18)	C7—N7—C11	111.4 (6)
O6—Gd—O2	127.81 (18)	C7—N7—C9	111.7 (6)
O8—Gd—O2	75.77 (18)	C11—N7—C9	109.3 (5)
O4—Gd—O12	77.25 (17)	C7—N7—Gd	109.7 (4)
O10—Gd—O12	94.34 (19)	C11—N7—Gd	108.8 (4)
O6—Gd—O12	76.74 (19)	C9—N7—Gd	105.8 (4)
O8—Gd—O12	128.19 (17)	C5—N8—C1	111.8 (6)
O2—Gd—O12	151.47 (19)	C5—N8—C3	110.2 (6)
O4—Gd—O13	73.7 (2)	C1—N8—C3	109.3 (6)
O10—Gd—O13	72.6 (2)	C5—N8—Gd	110.0 (4)
O6—Gd—O13	140.9 (2)	C1—N8—Gd	109.2 (4)
O8—Gd—O13	139.3 (2)	C3—N8—Gd	106.1 (4)
O2—Gd—O13	75.4 (2)	C2—O2—Gd	126.2 (5)
O12—Gd—O13	76.1 (2)	C4—O4—Gd	127.0 (5)
O4—Gd—N8	66.90 (18)	C6—O6—Gd	127.2 (5)
O10—Gd—N8	131.94 (18)	C8—O8—Gd	126.1 (5)
O6—Gd—N8	65.22 (18)	C10—O10—Gd	122.7 (4)
O8—Gd—N8	71.54 (19)	C12—O12—Gd	125.3 (5)
O2—Gd—N8	63.51 (17)	N8—C1—C2	111.9 (6)
O12—Gd—N8	133.31 (19)	N8—C1—H1A	109.2
O13—Gd—N8	118.4 (2)	C2—C1—H1A	109.2
O4—Gd—N7	131.73 (18)	N8—C1—H1B	109.2
O10—Gd—N7	67.33 (17)	C2—C1—H1B	109.2
O6—Gd—N7	71.33 (18)	H1A—C1—H1B	107.9
O8—Gd—N7	65.37 (17)	O1—C2—O2	124.6 (7)
O2—Gd—N7	132.74 (18)	O1—C2—C1	118.4 (7)
O12—Gd—N7	63.53 (17)	O2—C2—C1	117.0 (6)
O13—Gd—N7	118.97 (19)	N8—C3—C4	113.0 (6)
N8—Gd—N7	122.66 (19)	N8—C3—H3A	109.0
N4—Co—N2	179.4 (3)	C4—C3—H3A	109.0
N4—Co—N3	88.5 (3)	N8—C3—H3B	109.0
N2—Co—N3	91.5 (3)	C4—C3—H3B	109.0
N4—Co—N5	90.4 (3)	H3A—C3—H3B	107.8
N2—Co—N5	89.5 (3)	O3—C4—O4	127.6 (7)
N3—Co—N5	178.9 (3)	O3—C4—C3	119.0 (7)
N4—Co—N6	89.2 (3)	O4—C4—C3	113.4 (6)
N2—Co—N6	90.2 (3)	N8—C5—C6	113.9 (6)
N3—Co—N6	91.0 (3)	N8—C5—H5A	108.8
N5—Co—N6	89.3 (3)	C6—C5—H5A	108.8
N4—Co—N1	90.9 (3)	N8—C5—H5B	108.8
N2—Co—N1	89.6 (3)	C6—C5—H5B	108.8
N3—Co—N1	90.2 (3)	H5A—C5—H5B	107.7
N5—Co—N1	89.4 (3)	O6—C6—O5	125.1 (7)
N6—Co—N1	178.8 (3)	O6—C6—C5	118.0 (7)
Co—N1—H1C	109.5	O5—C6—C5	116.8 (7)
Co—N1—H1D	109.5	N7—C7—C8	114.5 (6)
H1C—N1—H1D	109.5	N7—C7—H7A	108.6
Co—N1—H1E	109.5	C8—C7—H7A	108.6
H1C—N1—H1E	109.5	N7—C7—H7B	108.6
H1D—N1—H1E	109.5	C8—C7—H7B	108.6
Co—N2—H2A	109.5	H7A—C7—H7B	107.6
Co—N2—H2B	109.5	O8—C8—O7	124.7 (7)
H2A—N2—H2B	109.5	O8—C8—C7	118.6 (7)
Co—N2—H2C	109.5	O7—C8—C7	116.6 (7)
H2A—N2—H2C	109.5	N7—C9—C10	112.1 (6)
H2B—N2—H2C	109.5	N7—C9—H9A	109.2
Co—N3—H3C	109.5	C10—C9—H9A	109.2
Co—N3—H3D	109.5	N7—C9—H9B	109.2
H3C—N3—H3D	109.5	C10—C9—H9B	109.2
Co—N3—H3E	109.5	H9A—C9—H9B	107.9
H3C—N3—H3E	109.5	O9—C10—O10	124.4 (7)
H3D—N3—H3E	109.5	O9—C10—C9	118.4 (6)
Co—N4—H4A	109.5	O10—C10—C9	117.2 (6)
Co—N4—H4B	109.5	N7—C11—C12	112.1 (6)
H4A—N4—H4B	109.5	N7—C11—H11A	109.2
Co—N4—H4C	109.5	C12—C11—H11A	109.2
H4A—N4—H4C	109.5	N7—C11—H11B	109.2
H4B—N4—H4C	109.5	C12—C11—H11B	109.2
Co—N5—H5C	109.5	H11A—C11—H11B	107.9
Co—N5—H5D	109.5	O11—C12—O12	124.1 (7)
H5C—N5—H5D	109.5	O11—C12—C11	118.3 (7)
Co—N5—H5E	109.5	O12—C12—C11	117.5 (6)
H5C—N5—H5E	109.5