{μ-6,6′-Dimeth­oxy-2,2′-[butane-1,4-diylbis(nitrilo­methyl­idyne)]diphenolato-1:2κ8O6,O1,O1′,O6′:O1,N,N′,O1′}tris­(nitrato-1κ2O,O′)copper(II)gadolinium(III)

Chan, C.; Yang, X.; Jones, R.A.; Holliday, B.J.; Stanley, J.M.

doi:10.1107/S1600536810014716

metal-organic compounds

CRYSTALLOGRAPHIC
COMMUNICATIONS

ISSN: 2056-9890

Volume 66| Part 5| May 2010| Pages m576-m577

https://doi.org/10.1107/S1600536810014716

Open

access

{μ-6,6′-Dimethoxy-2,2′-[butane-1,4-diylbis(nitrilomethylidyne)]diphenolato-1:2κ⁸O⁶,O¹,O^1′,O^6′:O¹,N,N′,O^1′}tris(nitrato-1κ²O,O′)copper(II)gadolinium(III)

Christopher Chan,^a Xiaoping Yang,^a Richard A. Jones,^a ^* Bradley J. Holliday ^a ^* and Julie M. Stanley ^a

^aDepartment of Chemistry & Biochemistry, The University of Texas at Austin, 1 University Station A5300, Austin, TX 78712-0165, USA
^*Correspondence e-mail: rajones@mail.utexas.edu, bholliday@cm.utexas.edu

(Received 16 February 2010; accepted 21 April 2010; online 28 April 2010)

In the title dinuclear complex, [CuGd(C₂₀H₂₂N₂O₄)(NO₃)₃], the Cu^II ion is located in the inner N₂O₂ cavity of the Schiff base ligand and adopts a distorted square-planar geometry. The Gd^III ion is ten-coordinate being bound to ten O atoms, four from the Schiff base ligand and six from three bidentate nitrate anions. The Cu^II and Gd^III ions are linked by two phenolate O atoms of the Schiff base ligand, with a separation of 3.5185 (9) Å.

Related literature

For general background to 3d–4f bimetallic complexes, see: Sakamoto et al. (2001 ); Winpenny (1998 ); Yang et al. (2005 ). For related structures, see: Fei & Fang (2008 ); Xing et al. (2008 ).

Experimental

Crystal data

[CuGd(C₂₀H₂₂N₂O₄)(NO₃)₃]
M_r = 761.22
Monoclinic, P 2₁ /n
a = 11.795 (2) Å
b = 14.730 (3) Å
c = 14.892 (3) Å
β = 100.58 (3)°
V = 2543.4 (9) Å³
Z = 4
Mo Kα radiation
μ = 3.50 mm⁻¹
T = 223 K
0.56 × 0.13 × 0.13 mm

Data collection

Rigaku MiniFlexII CCD diffractometer
Absorption correction: multi-scan (CrystalClear; Rigaku/MSC, 2002 ) T_min = 0.598, T_max = 1.000
14367 measured reflections
4460 independent reflections
4090 reflections with I > 2σ(I)
R_int = 0.032

Refinement

R[F² > 2σ(F²)] = 0.033
wR(F²) = 0.128
S = 1.20
4460 reflections
362 parameters
6 restraints
H-atom parameters constrained
Δρ_max = 2.69 e Å⁻³
Δρ_min = −1.35 e Å⁻³

Table 1
Selected bond lengths (Å)

Gd1—O1	2.581 (4)
Gd1—O2	2.336 (3)
Gd1—O3	2.418 (3)
Gd1—O4	2.568 (3)
Gd1—O5	2.472 (5)
Gd1—O6	2.458 (5)
Gd1—O8	2.472 (4)
Gd1—O9	2.428 (4)
Gd1—O11	2.431 (4)
Gd1—O12	2.520 (3)
Cu1—O2	1.941 (3)
Cu1—O3	1.940 (3)
Cu1—N1	2.004 (4)
Cu1—N2	1.960 (4)

Data collection: CrystalClear (Rigaku/MSC, 2002); cell refinement: CrystalClear; data reduction: CrystalClear; program(s) used to solve structure: SHELXTL (Sheldrick, 2008 ); program(s) used to refine structure: SHELXTL; molecular graphics: SHELXTL; software used to prepare material for publication: SHELXTL.

Supporting information

Crystal structure: contains datablocks I, global. DOI: https://doi.org/10.1107/S1600536810014716/hy2285sup1.cif

Structure factors: contains datablock I. DOI: https://doi.org/10.1107/S1600536810014716/hy2285Isup2.hkl

checkCIF report

Comment top

Heteropolynuclear complexes containing d- and f-block elements are currently of great interest because of their interesting physicochemical properties and potential applications as new materials (Sakamoto et al., 2001; Winpenny, 1998). Compartmental Schiff bases with two dissimilar metal-binding sites, one being specific for the d-block metal ion and another for the f-block metal ion, are classical ligands used to synthesize such heteronuclear complexes. As part of our ongoing interests in 3d–4f complexes with Schiff-base ligands (Yang et al., 2005), the title complex was synthesized and its crystal structure is reported herein.

The molecular structure of the title complex is shown in Fig. 1. It has a similar structure to other two Cu–Ln complexes with the Schiff-base ligand N,N'-bis(3-methoxysalicylidene)propane-1,3-diamine (H₂L), [CuLnL(NO₃)₃] [Ln = Eu^III (Xing et al., 2008) and Tb^III (Fei & Fang, 2008)]. The Cu^II ion is coordinated by two N atoms and two O atoms from the Schiff-base ligand. The Gd^III ion is surrounded by ten O atoms, four from the Schiff-base ligand and six from three bidentate NO₃^- anions. Cu^II and Gd^III ions are bridged by two phenolate O atoms of the Schiff-base ligand, with a separation of 3.5185 (9) Å. The average distances for the Cu—O(phenolate) and Cu—N are 1.942 Å and 1.982 Å, respectively. The Gd—O(phenolate) distance of 2.377 Å (av.) is shorter than the Gd—O (methoxy) distance of 2.574 Å (av.), no doubt reflecting the difference between ionic vs. dative bonding. The average distance for the Gd—O (nitrate) is 2.464 Å, which is comparable to those found in the literature (Fei & Fang, 2008; Xing et al., 2008).

Related literature top

For general background to 3d–4f bimetallic complexes, see: Sakamoto et al. (2001); Winpenny (1998); Yang et al. (2005). For related structures, see: Fei & Fang (2008); Xing et al. (2008).

Experimental top

A mixture of the Schiff-base ligand (0.178 g, 0.5 mmol) and Cu(CH₃CO₂)₂.H₂O (0.10 g, 0.5 mmol) in EtOH (15 ml) was stirred and refluxed for 10 min. The reaction mixture was allowed to cool briefly and Gd(NO₃)₃.6H₂O (0.226 g, 0.5 mmol) was added and the mixture again heated under reflux (15 min) and then filtered. Diethylether was allowed to diffuse slowly into the filtrate at room temperature and blue crystals were obtained after two weeks. The crystals were filtered off and washed with 5 ml of EtOH (yield 0.176 g, 46.32%). m. p. > 260°C (dec). ESI-MS(MeOH) m/z: 700 [M—NO₃]⁺. IR(CH₃OH, cm^-1): 3429 m, 1636 s, 1473 s, 1439 w, 1362 m, 1295 w, 1227 m, 1171 w, 1099 w, 1077 m, 1013 m, 658 s. UV-VIS(CH₃OH, 25°C) λ_max/nm: 215, 275, 350.

Structure description top

For general background to 3d–4f bimetallic complexes, see: Sakamoto et al. (2001); Winpenny (1998); Yang et al. (2005). For related structures, see: Fei & Fang (2008); Xing et al. (2008).

Computing details top

Data collection: CrystalClear (Rigaku/MSC, 2002); cell refinement: CrystalClear (Rigaku/MSC, 2002); data reduction: CrystalClear (Rigaku/MSC, 2002); program(s) used to solve structure: SHELXTL (Sheldrick, 2008); program(s) used to refine structure: SHELXTL (Sheldrick, 2008); molecular graphics: SHELXTL (Sheldrick, 2008); software used to prepare material for publication: SHELXTL (Sheldrick, 2008).

Figures top

Fig. 1. The molecular structure of the title complex, with displacement ellipsoids shown at the 40% probability level. H atoms have been excluded for clarity.

{µ-6,6'-Dimethoxy-2,2'-[butane-1,4-diylbis(nitrilomethylidyne)]diphenolato- 1:2κ⁸O⁶,O¹,O^1',O^6': O¹,N,N',O^1'}tris(nitrato- 1κ²O,O')copper(II)gadolinium(III) top

Crystal data top

[CuGd(C₂₀H₂₂N₂O₄)(NO₃)₃]	F(000) = 1496
M_r = 761.22	D_x = 1.988 Mg m⁻³
Monoclinic, P2₁/n	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2yn	Cell parameters from 8776 reflections
a = 11.795 (2) Å	θ = 1.8–31.9°
b = 14.730 (3) Å	µ = 3.50 mm⁻¹
c = 14.892 (3) Å	T = 223 K
β = 100.58 (3)°	Prism, blue
V = 2543.4 (9) Å³	0.56 × 0.13 × 0.13 mm
Z = 4

Data collection top

Rigaku MiniFlexII CCD diffractometer	4460 independent reflections
Radiation source: fine-focus sealed tube	4090 reflections with I > 2σ(I)
Graphite monochromator	R_int = 0.032
Detector resolution: 13.6612 pixels mm^-1	θ_max = 25.0°, θ_min = 2.0°
thin–slice ω scans	h = −14→14
Absorption correction: multi-scan (CrystalClear; Rigaku/MSC, 2002)	k = −17→17
T_min = 0.598, T_max = 1.000	l = −17→16
14367 measured reflections

Refinement top

Refinement on F²	Secondary atom site location: difference Fourier map
Least-squares matrix: full	Hydrogen site location: inferred from neighbouring sites
R[F² > 2σ(F²)] = 0.033	H-atom parameters constrained
wR(F²) = 0.128	w = 1/[σ²(F_o²) + (0.0793P)² + 1.3271P] where P = (F_o² + 2F_c²)/3
S = 1.20	(Δ/σ)_max = 0.001
4460 reflections	Δρ_max = 2.69 e Å⁻³
362 parameters	Δρ_min = −1.35 e Å⁻³
6 restraints	Extinction correction: SHELXTL (Sheldrick, 2008)
Primary atom site location: structure-invariant direct methods	Extinction coefficient: 0.0022 (4)

Crystal data top

[CuGd(C₂₀H₂₂N₂O₄)(NO₃)₃]	V = 2543.4 (9) Å³
M_r = 761.22	Z = 4
Monoclinic, P2₁/n	Mo Kα radiation
a = 11.795 (2) Å	µ = 3.50 mm⁻¹
b = 14.730 (3) Å	T = 223 K
c = 14.892 (3) Å	0.56 × 0.13 × 0.13 mm
β = 100.58 (3)°

Data collection top

Rigaku MiniFlexII CCD diffractometer	4460 independent reflections
Absorption correction: multi-scan (CrystalClear; Rigaku/MSC, 2002)	4090 reflections with I > 2σ(I)
T_min = 0.598, T_max = 1.000	R_int = 0.032
14367 measured reflections

Refinement top

R[F² > 2σ(F²)] = 0.033	6 restraints
wR(F²) = 0.128	H-atom parameters constrained
S = 1.20	Δρ_max = 2.69 e Å⁻³
4460 reflections	Δρ_min = −1.35 e Å⁻³
362 parameters

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å²) top

	x	y	z	U_iso*/U_eq
Gd1	0.261236 (19)	0.750997 (12)	0.066103 (16)	0.02180 (16)
Cu1	0.54871 (5)	0.76924 (4)	0.03441 (4)	0.02328 (19)
N1	0.6472 (3)	0.6645 (3)	0.0102 (3)	0.0281 (9)
N2	0.6638 (3)	0.8666 (3)	0.0545 (3)	0.0251 (8)
O1	0.2007 (3)	0.6647 (3)	−0.0860 (2)	0.0345 (8)
O2	0.4094 (3)	0.6988 (2)	−0.0053 (2)	0.0305 (7)
O3	0.4328 (3)	0.8431 (2)	0.0767 (2)	0.0275 (7)
O4	0.2582 (3)	0.9074 (2)	0.1417 (2)	0.0337 (8)
C1	0.0855 (5)	0.6569 (5)	−0.1376 (5)	0.0605 (18)
H1A	0.0850	0.6743	−0.2005	0.091*
H1B	0.0345	0.6967	−0.1116	0.091*
H1C	0.0593	0.5947	−0.1356	0.091*
C2	0.2860 (4)	0.6140 (3)	−0.1153 (3)	0.0294 (10)
C3	0.2659 (5)	0.5475 (3)	−0.1817 (3)	0.0345 (11)
H3A	0.1904	0.5355	−0.2124	0.041*
C4	0.3593 (5)	0.4980 (4)	−0.2032 (4)	0.0406 (13)
H4A	0.3463	0.4524	−0.2482	0.049*
C5	0.4697 (5)	0.5162 (4)	−0.1584 (4)	0.0386 (12)
H5A	0.5316	0.4820	−0.1721	0.046*
C6	0.4913 (4)	0.5862 (3)	−0.0915 (3)	0.0306 (10)
C7	0.3977 (4)	0.6343 (3)	−0.0690 (3)	0.0277 (10)
C8	0.6085 (4)	0.5997 (3)	−0.0437 (3)	0.0326 (11)
H8A	0.6625	0.5556	−0.0536	0.039*
C9	0.7715 (4)	0.6524 (4)	0.0540 (4)	0.0402 (14)
H9A	0.8203	0.6674	0.0095	0.048*
H9B	0.7850	0.5886	0.0713	0.048*
C10	0.8059 (5)	0.7113 (5)	0.1378 (4)	0.0426 (13)
H10A	0.8640	0.6792	0.1820	0.051*
H10B	0.7383	0.7215	0.1662	0.051*
C11	0.8552 (4)	0.8039 (4)	0.1151 (4)	0.0433 (14)
H11A	0.8623	0.8434	0.1688	0.052*
H11B	0.9327	0.7948	0.1016	0.052*
C12	0.7812 (5)	0.8503 (4)	0.0350 (4)	0.0338 (12)
H12A	0.8164	0.9083	0.0230	0.041*
H12B	0.7760	0.8123	−0.0196	0.041*
C13	0.6435 (4)	0.9476 (3)	0.0807 (3)	0.0263 (10)
H13A	0.7029	0.9901	0.0806	0.032*
C14	0.5420 (4)	0.9812 (3)	0.1102 (3)	0.0238 (9)
C15	0.5441 (4)	1.0721 (3)	0.1420 (3)	0.0286 (10)
H15A	0.6097	1.1082	0.1417	0.034*
C16	0.4500 (4)	1.1079 (4)	0.1733 (3)	0.0349 (11)
H16A	0.4512	1.1684	0.1937	0.042*
C17	0.3544 (4)	1.0541 (3)	0.1745 (3)	0.0307 (10)
H17A	0.2913	1.0779	0.1972	0.037*
C18	0.3500 (4)	0.9666 (3)	0.1433 (3)	0.0261 (9)
C19	0.4434 (4)	0.9281 (3)	0.1088 (3)	0.0219 (9)
C20	0.1675 (5)	0.9375 (5)	0.1878 (5)	0.0593 (18)
H20A	0.2008	0.9574	0.2491	0.089*
H20B	0.1146	0.8877	0.1912	0.089*
H20C	0.1262	0.9875	0.1542	0.089*
N3	0.3210 (8)	0.7319 (5)	0.2617 (4)	0.085 (3)
O5	0.3967 (6)	0.7260 (5)	0.2116 (4)	0.0811 (19)
O6	0.2209 (7)	0.7391 (3)	0.2219 (4)	0.0643 (17)
O7	0.3486 (8)	0.7274 (6)	0.3444 (5)	0.135 (3)
N4	0.1158 (4)	0.8781 (3)	−0.0484 (3)	0.0408 (11)
O8	0.2183 (3)	0.8626 (3)	−0.0595 (2)	0.0370 (9)
O9	0.0797 (3)	0.8273 (3)	0.0094 (3)	0.0380 (8)
O10	0.0586 (5)	0.9393 (4)	−0.0899 (4)	0.0827 (17)
N5	0.1497 (4)	0.5795 (3)	0.0913 (3)	0.0397 (10)
O11	0.2586 (3)	0.5895 (3)	0.0994 (3)	0.0396 (9)
O12	0.0899 (3)	0.6504 (3)	0.0719 (3)	0.0421 (9)
O13	0.1069 (5)	0.5050 (3)	0.1020 (3)	0.0727 (15)

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
Gd1	0.0171 (2)	0.0226 (2)	0.0268 (2)	−0.00134 (7)	0.00685 (14)	−0.00039 (7)
Cu1	0.0182 (3)	0.0237 (3)	0.0291 (3)	−0.0009 (2)	0.0074 (2)	−0.0030 (2)
N1	0.0213 (19)	0.023 (2)	0.042 (2)	0.0040 (16)	0.0126 (17)	0.0029 (18)
N2	0.0184 (18)	0.028 (2)	0.031 (2)	−0.0008 (16)	0.0101 (15)	−0.0004 (17)
O1	0.0271 (18)	0.037 (2)	0.0385 (18)	−0.0008 (16)	0.0028 (15)	−0.0079 (17)
O2	0.0229 (16)	0.0314 (18)	0.0381 (18)	−0.0031 (14)	0.0085 (14)	−0.0118 (15)
O3	0.0225 (16)	0.0221 (16)	0.0408 (18)	−0.0048 (13)	0.0132 (14)	−0.0067 (14)
O4	0.0230 (16)	0.0337 (19)	0.049 (2)	−0.0025 (15)	0.0196 (15)	−0.0092 (16)
C1	0.029 (3)	0.078 (5)	0.067 (4)	−0.001 (3)	−0.010 (3)	−0.026 (4)
C2	0.027 (2)	0.030 (3)	0.031 (2)	0.000 (2)	0.0073 (19)	0.001 (2)
C3	0.040 (3)	0.033 (3)	0.028 (2)	−0.008 (2)	0.002 (2)	−0.005 (2)
C4	0.053 (3)	0.037 (3)	0.035 (3)	−0.001 (3)	0.016 (2)	−0.009 (2)
C5	0.049 (3)	0.029 (3)	0.043 (3)	−0.002 (2)	0.022 (2)	−0.005 (2)
C6	0.035 (3)	0.024 (2)	0.035 (3)	−0.003 (2)	0.014 (2)	−0.002 (2)
C7	0.035 (3)	0.022 (2)	0.028 (2)	−0.0046 (19)	0.0119 (19)	−0.0014 (19)
C8	0.031 (2)	0.025 (2)	0.046 (3)	0.004 (2)	0.017 (2)	−0.003 (2)
C9	0.022 (3)	0.033 (3)	0.066 (4)	0.006 (2)	0.007 (3)	0.007 (3)
C10	0.026 (3)	0.058 (4)	0.043 (3)	0.004 (3)	0.004 (2)	0.010 (3)
C11	0.019 (2)	0.057 (4)	0.054 (3)	0.000 (2)	0.007 (2)	−0.013 (3)
C12	0.028 (3)	0.030 (3)	0.050 (3)	−0.005 (2)	0.024 (2)	−0.002 (2)
C13	0.026 (2)	0.027 (2)	0.027 (2)	−0.0076 (19)	0.0066 (18)	0.0012 (19)
C14	0.025 (2)	0.024 (2)	0.023 (2)	0.0006 (18)	0.0039 (17)	−0.0005 (18)
C15	0.031 (2)	0.025 (2)	0.030 (2)	−0.002 (2)	0.0064 (19)	−0.005 (2)
C16	0.034 (3)	0.029 (3)	0.041 (3)	0.002 (2)	0.004 (2)	−0.008 (2)
C17	0.026 (2)	0.031 (2)	0.038 (2)	0.004 (2)	0.0113 (19)	−0.006 (2)
C18	0.026 (2)	0.026 (2)	0.028 (2)	−0.0019 (18)	0.0096 (18)	−0.0008 (19)
C19	0.021 (2)	0.022 (2)	0.023 (2)	0.0007 (18)	0.0052 (16)	−0.0005 (18)
C20	0.041 (3)	0.065 (4)	0.083 (5)	−0.008 (3)	0.041 (3)	−0.030 (4)
N3	0.108 (7)	0.111 (5)	0.032 (3)	−0.088 (5)	−0.002 (4)	0.011 (3)
O5	0.068 (4)	0.113 (4)	0.052 (3)	−0.045 (4)	−0.015 (3)	0.027 (3)
O6	0.099 (5)	0.056 (3)	0.047 (3)	−0.031 (3)	0.037 (3)	−0.004 (2)
O7	0.149 (6)	0.203 (7)	0.047 (3)	−0.114 (5)	0.000 (4)	0.020 (4)
N4	0.038 (2)	0.036 (3)	0.048 (3)	0.001 (2)	0.008 (2)	0.006 (2)
O8	0.0287 (18)	0.035 (2)	0.049 (2)	−0.0025 (16)	0.0136 (16)	0.0100 (17)
O9	0.0300 (18)	0.041 (2)	0.044 (2)	−0.0057 (16)	0.0112 (16)	0.0052 (17)
O10	0.081 (4)	0.066 (3)	0.102 (4)	0.030 (3)	0.019 (3)	0.048 (3)
N5	0.044 (3)	0.034 (2)	0.040 (2)	−0.016 (2)	0.006 (2)	−0.001 (2)
O11	0.037 (2)	0.0297 (19)	0.053 (2)	0.0049 (16)	0.0118 (17)	0.0050 (18)
O12	0.0273 (19)	0.042 (2)	0.057 (2)	−0.0071 (17)	0.0080 (17)	0.0070 (19)
O13	0.099 (4)	0.041 (3)	0.078 (3)	−0.028 (3)	0.014 (3)	0.007 (2)

Geometric parameters (Å, º) top

Gd1—O1	2.581 (4)	C6—C8	1.447 (7)
Gd1—O2	2.336 (3)	C8—H8A	0.9400
Gd1—O3	2.418 (3)	C9—C10	1.512 (9)
Gd1—O4	2.568 (3)	C9—H9A	0.9800
Gd1—O5	2.472 (5)	C9—H9B	0.9800
Gd1—O6	2.458 (5)	C10—C11	1.544 (9)
Gd1—O8	2.472 (4)	C10—H10A	0.9800
Gd1—O9	2.428 (4)	C10—H10B	0.9800
Gd1—O11	2.431 (4)	C11—C12	1.507 (8)
Gd1—O12	2.520 (3)	C11—H11A	0.9800
Cu1—O2	1.941 (3)	C11—H11B	0.9800
Cu1—O3	1.940 (3)	C12—H12A	0.9800
Cu1—N1	2.004 (4)	C12—H12B	0.9800
Cu1—N2	1.960 (4)	C13—C14	1.436 (6)
N1—C8	1.276 (6)	C13—H13A	0.9400
N1—C9	1.502 (6)	C14—C19	1.398 (6)
N2—C13	1.292 (6)	C14—C15	1.419 (6)
N2—C12	1.486 (6)	C15—C16	1.385 (7)
O1—C2	1.386 (6)	C15—H15A	0.9400
O1—C1	1.437 (6)	C16—C17	1.382 (7)
O2—C7	1.332 (6)	C16—H16A	0.9400
O3—C19	1.338 (5)	C17—C18	1.367 (7)
O4—C18	1.387 (6)	C17—H17A	0.9400
O4—C20	1.443 (6)	C18—C19	1.417 (6)
C1—H1A	0.9700	C20—H20A	0.9700
C1—H1B	0.9700	C20—H20B	0.9700
C1—H1C	0.9700	C20—H20C	0.9700
C2—C3	1.381 (7)	N3—O7	1.218 (9)
C2—C7	1.403 (7)	N3—O6	1.224 (11)
C3—C4	1.406 (7)	N3—O5	1.266 (11)
C3—H3A	0.9400	N4—O10	1.224 (6)
C4—C5	1.377 (8)	N4—O8	1.270 (6)
C4—H4A	0.9400	N4—O9	1.272 (5)
C5—C6	1.424 (7)	N5—O13	1.230 (6)
C5—H5A	0.9400	N5—O12	1.264 (6)
C6—C7	1.404 (7)	N5—O11	1.277 (6)

O2—Gd1—O3	61.77 (11)	C2—C3—H3A	120.2
O2—Gd1—O9	132.81 (12)	C4—C3—H3A	120.2
O3—Gd1—O9	115.90 (12)	C5—C4—C3	119.9 (5)
O2—Gd1—O11	79.02 (12)	C5—C4—H4A	120.0
O3—Gd1—O11	125.29 (12)	C3—C4—H4A	120.0
O9—Gd1—O11	118.72 (12)	C4—C5—C6	120.8 (5)
O2—Gd1—O6	134.1 (2)	C4—C5—H5A	119.6
O3—Gd1—O6	106.44 (17)	C6—C5—H5A	119.6
O9—Gd1—O6	92.9 (2)	C7—C6—C5	119.0 (5)
O11—Gd1—O6	74.10 (14)	C7—C6—C8	122.4 (4)
O2—Gd1—O8	86.60 (12)	C5—C6—C8	118.4 (5)
O3—Gd1—O8	74.26 (12)	O2—C7—C2	117.9 (4)
O9—Gd1—O8	51.97 (12)	O2—C7—C6	123.2 (4)
O11—Gd1—O8	142.79 (13)	C2—C7—C6	119.0 (4)
O6—Gd1—O8	135.51 (17)	N1—C8—C6	127.7 (4)
O2—Gd1—O5	86.1 (2)	N1—C8—H8A	116.2
O3—Gd1—O5	68.18 (15)	C6—C8—H8A	116.2
O9—Gd1—O5	139.5 (2)	N1—C9—C10	112.6 (5)
O11—Gd1—O5	72.88 (18)	N1—C9—H9A	109.1
O6—Gd1—O5	50.8 (2)	C10—C9—H9A	109.1
O8—Gd1—O5	140.55 (16)	N1—C9—H9B	109.1
O2—Gd1—O12	119.60 (12)	C10—C9—H9B	109.1
O3—Gd1—O12	174.12 (12)	H9A—C9—H9B	107.8
O9—Gd1—O12	67.83 (12)	C9—C10—C11	112.4 (5)
O11—Gd1—O12	51.51 (13)	C9—C10—H10A	109.1
O6—Gd1—O12	68.33 (17)	C11—C10—H10A	109.1
O8—Gd1—O12	111.26 (12)	C9—C10—H10B	109.1
O5—Gd1—O12	105.99 (16)	C11—C10—H10B	109.1
O2—Gd1—O4	124.51 (11)	H10A—C10—H10B	107.9
O3—Gd1—O4	63.05 (10)	C12—C11—C10	112.8 (4)
O9—Gd1—O4	69.79 (12)	C12—C11—H11A	109.0
O11—Gd1—O4	141.89 (12)	C10—C11—H11A	109.0
O6—Gd1—O4	68.24 (13)	C12—C11—H11B	109.0
O8—Gd1—O4	73.61 (12)	C10—C11—H11B	109.0
O5—Gd1—O4	78.95 (19)	H11A—C11—H11B	107.8
O12—Gd1—O4	115.88 (12)	N2—C12—C11	110.1 (4)
O2—Gd1—O1	63.16 (11)	N2—C12—H12A	109.6
O3—Gd1—O1	115.29 (11)	C11—C12—H12A	109.6
O9—Gd1—O1	80.71 (12)	N2—C12—H12B	109.6
O11—Gd1—O1	71.65 (13)	C11—C12—H12B	109.6
O6—Gd1—O1	136.28 (15)	H12A—C12—H12B	108.2
O8—Gd1—O1	71.23 (12)	N2—C13—C14	128.4 (4)
O5—Gd1—O1	136.5 (2)	N2—C13—H13A	115.8
O12—Gd1—O1	69.26 (13)	C14—C13—H13A	115.8
O4—Gd1—O1	143.41 (12)	C19—C14—C15	119.7 (4)
O3—Cu1—O2	77.94 (13)	C19—C14—C13	122.7 (4)
O3—Cu1—N2	92.82 (14)	C15—C14—C13	117.6 (4)
O2—Cu1—N2	164.02 (16)	C16—C15—C14	120.5 (5)
O3—Cu1—N1	163.09 (15)	C16—C15—H15A	119.8
O2—Cu1—N1	91.16 (15)	C14—C15—H15A	119.8
N2—Cu1—N1	100.54 (16)	C17—C16—C15	119.4 (5)
O3—Cu1—Gd1	41.03 (9)	C17—C16—H16A	120.3
O2—Cu1—Gd1	38.50 (9)	C15—C16—H16A	120.3
N2—Cu1—Gd1	133.86 (11)	C18—C17—C16	121.1 (4)
N1—Cu1—Gd1	124.78 (11)	C18—C17—H17A	119.4
C8—N1—C9	113.1 (4)	C16—C17—H17A	119.4
C8—N1—Cu1	122.5 (3)	C17—C18—O4	125.4 (4)
C9—N1—Cu1	124.4 (3)	C17—C18—C19	121.2 (4)
C13—N2—C12	116.1 (4)	O4—C18—C19	113.5 (4)
C13—N2—Cu1	124.1 (3)	O3—C19—C14	123.5 (4)
C12—N2—Cu1	119.7 (3)	O3—C19—C18	118.5 (4)
C2—O1—C1	117.3 (4)	C14—C19—C18	118.1 (4)
C2—O1—Gd1	116.2 (3)	O4—C20—H20A	109.5
C1—O1—Gd1	126.2 (3)	O4—C20—H20B	109.5
C7—O2—Cu1	124.7 (3)	H20A—C20—H20B	109.5
C7—O2—Gd1	124.8 (3)	O4—C20—H20C	109.5
Cu1—O2—Gd1	110.36 (14)	H20A—C20—H20C	109.5
C19—O3—Cu1	128.0 (3)	H20B—C20—H20C	109.5
C19—O3—Gd1	124.8 (3)	O7—N3—O6	123.3 (10)
Cu1—O3—Gd1	107.17 (14)	O7—N3—O5	120.4 (10)
C18—O4—C20	116.3 (4)	O6—N3—O5	116.2 (6)
C18—O4—Gd1	119.9 (3)	N3—O5—Gd1	95.4 (5)
C20—O4—Gd1	123.7 (3)	N3—O6—Gd1	97.3 (5)
O1—C1—H1A	109.5	O10—N4—O8	121.1 (5)
O1—C1—H1B	109.5	O10—N4—O9	123.6 (5)
H1A—C1—H1B	109.5	O8—N4—O9	115.3 (4)
O1—C1—H1C	109.5	N4—O8—Gd1	95.1 (3)
H1A—C1—H1C	109.5	N4—O9—Gd1	97.2 (3)
H1B—C1—H1C	109.5	O13—N5—O12	122.9 (5)
C3—C2—O1	124.7 (4)	O13—N5—O11	121.3 (5)
C3—C2—C7	121.7 (4)	O12—N5—O11	115.8 (4)
O1—C2—C7	113.6 (4)	N5—O11—Gd1	98.3 (3)
C2—C3—C4	119.5 (5)	N5—O12—Gd1	94.4 (3)

O2—Gd1—Cu1—O3	159.0 (2)	O12—Gd1—O4—C18	178.8 (3)
O9—Gd1—Cu1—O3	59.78 (19)	O1—Gd1—O4—C18	−91.6 (4)
O11—Gd1—Cu1—O3	−149.68 (18)	N4—Gd1—O4—C18	−102.1 (3)
O6—Gd1—Cu1—O3	−73.1 (2)	N3—Gd1—O4—C18	101.7 (4)
O8—Gd1—Cu1—O3	67.60 (18)	O2—Gd1—O4—C20	−178.1 (4)
O5—Gd1—Cu1—O3	−81.8 (2)	O3—Gd1—O4—C20	−171.7 (5)
O12—Gd1—Cu1—O3	−168.9 (2)	O9—Gd1—O4—C20	53.2 (5)
O4—Gd1—Cu1—O3	−5.48 (18)	O11—Gd1—O4—C20	−58.0 (5)
O1—Gd1—Cu1—O3	138.55 (18)	O6—Gd1—O4—C20	−48.6 (5)
N4—Gd1—Cu1—O3	62.47 (19)	O8—Gd1—O4—C20	108.0 (5)
N3—Gd1—Cu1—O3	−76.2 (2)	O5—Gd1—O4—C20	−100.7 (5)
O3—Gd1—Cu1—O2	−159.0 (2)	O12—Gd1—O4—C20	1.9 (5)
O9—Gd1—Cu1—O2	−99.2 (2)	O1—Gd1—O4—C20	91.5 (5)
O11—Gd1—Cu1—O2	51.3 (2)	N4—Gd1—O4—C20	81.0 (5)
O6—Gd1—Cu1—O2	127.9 (2)	N3—Gd1—O4—C20	−75.2 (5)
O8—Gd1—Cu1—O2	−91.38 (19)	C1—O1—C2—C3	−9.8 (8)
O5—Gd1—Cu1—O2	119.2 (2)	Gd1—O1—C2—C3	164.2 (4)
O12—Gd1—Cu1—O2	32.1 (2)	C1—O1—C2—C7	172.0 (5)
O4—Gd1—Cu1—O2	−164.46 (19)	Gd1—O1—C2—C7	−14.0 (5)
O1—Gd1—Cu1—O2	−20.43 (19)	O1—C2—C3—C4	−177.4 (5)
N4—Gd1—Cu1—O2	−96.5 (2)	C7—C2—C3—C4	0.7 (8)
N3—Gd1—Cu1—O2	124.9 (2)	C2—C3—C4—C5	−0.3 (8)
O2—Gd1—Cu1—N2	159.0 (2)	C3—C4—C5—C6	−1.3 (8)
O3—Gd1—Cu1—N2	0.0 (2)	C4—C5—C6—C7	2.5 (8)
O9—Gd1—Cu1—N2	59.8 (2)	C4—C5—C6—C8	177.4 (5)
O11—Gd1—Cu1—N2	−149.64 (19)	Cu1—O2—C7—C2	−155.9 (3)
O6—Gd1—Cu1—N2	−73.1 (2)	Gd1—O2—C7—C2	19.0 (6)
O8—Gd1—Cu1—N2	67.64 (18)	Cu1—O2—C7—C6	24.1 (6)
O5—Gd1—Cu1—N2	−81.7 (2)	Gd1—O2—C7—C6	−160.9 (3)
O12—Gd1—Cu1—N2	−168.8 (2)	C3—C2—C7—O2	−179.4 (4)
O4—Gd1—Cu1—N2	−5.44 (18)	O1—C2—C7—O2	−1.1 (6)
O1—Gd1—Cu1—N2	138.59 (18)	C3—C2—C7—C6	0.5 (7)
N4—Gd1—Cu1—N2	62.51 (19)	O1—C2—C7—C6	178.8 (4)
N3—Gd1—Cu1—N2	−76.1 (2)	C5—C6—C7—O2	177.8 (4)
O2—Gd1—Cu1—N1	−33.5 (2)	C8—C6—C7—O2	3.2 (7)
O3—Gd1—Cu1—N1	167.5 (2)	C5—C6—C7—C2	−2.1 (7)
O9—Gd1—Cu1—N1	−132.7 (2)	C8—C6—C7—C2	−176.8 (4)
O11—Gd1—Cu1—N1	17.83 (18)	C9—N1—C8—C6	174.9 (5)
O6—Gd1—Cu1—N1	94.39 (19)	Cu1—N1—C8—C6	−3.7 (7)
O8—Gd1—Cu1—N1	−124.89 (17)	C7—C6—C8—N1	−14.0 (8)
O5—Gd1—Cu1—N1	85.7 (2)	C5—C6—C8—N1	171.3 (5)
O12—Gd1—Cu1—N1	−1.4 (2)	C8—N1—C9—C10	−162.0 (5)
O4—Gd1—Cu1—N1	162.03 (17)	Cu1—N1—C9—C10	16.6 (7)
O1—Gd1—Cu1—N1	−53.95 (17)	N1—C9—C10—C11	−92.0 (6)
N4—Gd1—Cu1—N1	−130.02 (18)	C9—C10—C11—C12	48.1 (7)
N3—Gd1—Cu1—N1	91.3 (2)	C13—N2—C12—C11	99.6 (5)
O3—Cu1—N1—C8	70.4 (7)	Cu1—N2—C12—C11	−83.1 (5)
O2—Cu1—N1—C8	21.1 (4)	C10—C11—C12—N2	59.9 (6)
N2—Cu1—N1—C8	−147.9 (4)	C12—N2—C13—C14	−175.3 (5)
Gd1—Cu1—N1—C8	41.2 (4)	Cu1—N2—C13—C14	7.6 (7)
O3—Cu1—N1—C9	−108.1 (6)	N2—C13—C14—C19	−4.1 (7)
O2—Cu1—N1—C9	−157.4 (4)	N2—C13—C14—C15	175.6 (5)
N2—Cu1—N1—C9	33.6 (4)	C19—C14—C15—C16	1.3 (7)
Gd1—Cu1—N1—C9	−137.3 (4)	C13—C14—C15—C16	−178.5 (4)
O3—Cu1—N2—C13	−4.2 (4)	C14—C15—C16—C17	0.8 (7)
O2—Cu1—N2—C13	49.9 (7)	C15—C16—C17—C18	−1.5 (7)
N1—Cu1—N2—C13	−173.7 (4)	C16—C17—C18—O4	180.0 (5)
Gd1—Cu1—N2—C13	−4.2 (5)	C16—C17—C18—C19	0.2 (7)
O3—Cu1—N2—C12	178.8 (4)	C20—O4—C18—C17	−8.6 (7)
O2—Cu1—N2—C12	−127.2 (5)	Gd1—O4—C18—C17	174.3 (4)
N1—Cu1—N2—C12	9.2 (4)	C20—O4—C18—C19	171.2 (5)
Gd1—Cu1—N2—C12	178.8 (3)	Gd1—O4—C18—C19	−5.9 (5)
O2—Gd1—O1—C2	16.4 (3)	Cu1—O3—C19—C14	5.4 (6)
O3—Gd1—O1—C2	50.7 (3)	Gd1—O3—C19—C14	−176.9 (3)
O9—Gd1—O1—C2	165.1 (3)	Cu1—O3—C19—C18	−174.7 (3)
O11—Gd1—O1—C2	−70.4 (3)	Gd1—O3—C19—C18	2.9 (5)
O6—Gd1—O1—C2	−110.5 (4)	C15—C14—C19—O3	177.3 (4)
O8—Gd1—O1—C2	112.2 (3)	C13—C14—C19—O3	−3.0 (7)
O5—Gd1—O1—C2	−33.6 (4)	C15—C14—C19—C18	−2.5 (6)
O12—Gd1—O1—C2	−125.2 (3)	C13—C14—C19—C18	177.2 (4)
O4—Gd1—O1—C2	128.9 (3)	C17—C18—C19—O3	−178.0 (4)
N4—Gd1—O1—C2	138.9 (3)	O4—C18—C19—O3	2.2 (6)
N3—Gd1—O1—C2	−73.1 (5)	C17—C18—C19—C14	1.9 (7)
O2—Gd1—O1—C1	−170.3 (5)	O4—C18—C19—C14	−178.0 (4)
O3—Gd1—O1—C1	−135.9 (5)	O7—N3—O5—Gd1	−177.0 (8)
O9—Gd1—O1—C1	−21.6 (5)	O6—N3—O5—Gd1	5.4 (7)
O11—Gd1—O1—C1	103.0 (5)	O2—Gd1—O5—N3	−166.0 (5)
O6—Gd1—O1—C1	62.8 (6)	O3—Gd1—O5—N3	132.9 (5)
O8—Gd1—O1—C1	−74.5 (5)	O9—Gd1—O5—N3	28.1 (6)
O5—Gd1—O1—C1	139.7 (5)	O11—Gd1—O5—N3	−86.3 (5)
O12—Gd1—O1—C1	48.1 (5)	O6—Gd1—O5—N3	−3.1 (4)
O4—Gd1—O1—C1	−57.8 (5)	O8—Gd1—O5—N3	114.1 (4)
N4—Gd1—O1—C1	−47.8 (5)	O12—Gd1—O5—N3	−46.3 (5)
N3—Gd1—O1—C1	100.3 (6)	O4—Gd1—O5—N3	67.7 (5)
O3—Cu1—O2—C7	161.6 (4)	O1—Gd1—O5—N3	−122.8 (5)
N2—Cu1—O2—C7	105.9 (6)	N4—Gd1—O5—N3	70.5 (5)
N1—Cu1—O2—C7	−31.4 (4)	O7—N3—O6—Gd1	177.0 (8)
Gd1—Cu1—O2—C7	175.6 (5)	O5—N3—O6—Gd1	−5.5 (8)
O3—Cu1—O2—Gd1	−13.93 (15)	O2—Gd1—O6—N3	27.4 (5)
N2—Cu1—O2—Gd1	−69.7 (6)	O3—Gd1—O6—N3	−39.0 (5)
N1—Cu1—O2—Gd1	153.03 (17)	O9—Gd1—O6—N3	−157.0 (4)
O3—Gd1—O2—C7	−163.2 (4)	O11—Gd1—O6—N3	83.9 (5)
O9—Gd1—O2—C7	−62.9 (4)	O8—Gd1—O6—N3	−123.0 (5)
O11—Gd1—O2—C7	56.3 (4)	O5—Gd1—O6—N3	3.2 (5)
O6—Gd1—O2—C7	111.0 (4)	O12—Gd1—O6—N3	138.2 (5)
O8—Gd1—O2—C7	−89.2 (4)	O4—Gd1—O6—N3	−90.2 (5)
O5—Gd1—O2—C7	129.6 (4)	O1—Gd1—O6—N3	123.4 (4)
O12—Gd1—O2—C7	23.4 (4)	N4—Gd1—O6—N3	−141.5 (4)
O4—Gd1—O2—C7	−156.6 (3)	O10—N4—O8—Gd1	171.6 (5)
O1—Gd1—O2—C7	−18.6 (3)	O9—N4—O8—Gd1	−6.9 (5)
N4—Gd1—O2—C7	−79.8 (4)	O2—Gd1—O8—N4	159.8 (3)
N3—Gd1—O2—C7	123.0 (4)	O3—Gd1—O8—N4	−138.6 (3)
O3—Gd1—O2—Cu1	12.39 (14)	O9—Gd1—O8—N4	4.2 (3)
O9—Gd1—O2—Cu1	112.66 (18)	O11—Gd1—O8—N4	92.9 (3)
O11—Gd1—O2—Cu1	−128.16 (19)	O6—Gd1—O8—N4	−41.0 (4)
O6—Gd1—O2—Cu1	−73.4 (2)	O5—Gd1—O8—N4	−120.5 (4)
O8—Gd1—O2—Cu1	86.33 (17)	O12—Gd1—O8—N4	39.2 (3)
O5—Gd1—O2—Cu1	−54.9 (2)	O4—Gd1—O8—N4	−72.7 (3)
O12—Gd1—O2—Cu1	−161.09 (14)	O1—Gd1—O8—N4	97.0 (3)
O4—Gd1—O2—Cu1	18.9 (2)	N3—Gd1—O8—N4	−77.8 (5)
O1—Gd1—O2—Cu1	157.0 (2)	O10—N4—O9—Gd1	−171.4 (5)
N4—Gd1—O2—Cu1	95.71 (18)	O8—N4—O9—Gd1	7.1 (5)
N3—Gd1—O2—Cu1	−61.4 (2)	O2—Gd1—O9—N4	−38.4 (4)
O2—Cu1—O3—C19	−168.8 (4)	O3—Gd1—O9—N4	36.1 (3)
N2—Cu1—O3—C19	−2.0 (4)	O11—Gd1—O9—N4	−140.6 (3)
N1—Cu1—O3—C19	140.3 (5)	O6—Gd1—O9—N4	146.0 (3)
Gd1—Cu1—O3—C19	178.0 (4)	O8—Gd1—O9—N4	−4.2 (3)
O2—Cu1—O3—Gd1	13.20 (14)	O5—Gd1—O9—N4	122.3 (3)
N2—Cu1—O3—Gd1	−179.97 (16)	O12—Gd1—O9—N4	−148.8 (3)
N1—Cu1—O3—Gd1	−37.6 (6)	O4—Gd1—O9—N4	80.5 (3)
O2—Gd1—O3—C19	169.8 (4)	O1—Gd1—O9—N4	−77.5 (3)
O9—Gd1—O3—C19	43.1 (4)	N3—Gd1—O9—N4	135.5 (3)
O11—Gd1—O3—C19	−140.4 (3)	O13—N5—O11—Gd1	179.4 (5)
O6—Gd1—O3—C19	−58.5 (4)	O12—N5—O11—Gd1	−0.7 (5)
O8—Gd1—O3—C19	75.1 (3)	O2—Gd1—O11—N5	−142.4 (3)
O5—Gd1—O3—C19	−92.6 (4)	O3—Gd1—O11—N5	174.3 (3)
O4—Gd1—O3—C19	−4.2 (3)	O9—Gd1—O11—N5	−9.3 (3)
O1—Gd1—O3—C19	134.9 (3)	O6—Gd1—O11—N5	75.1 (3)
N4—Gd1—O3—C19	58.2 (3)	O8—Gd1—O11—N5	−73.2 (4)
N3—Gd1—O3—C19	−73.9 (4)	O5—Gd1—O11—N5	128.2 (3)
O2—Gd1—O3—Cu1	−12.16 (13)	O12—Gd1—O11—N5	0.4 (3)
O9—Gd1—O3—Cu1	−138.80 (14)	O4—Gd1—O11—N5	84.1 (3)
O11—Gd1—O3—Cu1	37.7 (2)	O1—Gd1—O11—N5	−77.3 (3)
O6—Gd1—O3—Cu1	119.6 (2)	N4—Gd1—O11—N5	−33.3 (4)
O8—Gd1—O3—Cu1	−106.83 (17)	N3—Gd1—O11—N5	101.1 (4)
O5—Gd1—O3—Cu1	85.5 (2)	O13—N5—O12—Gd1	−179.4 (5)
O4—Gd1—O3—Cu1	173.9 (2)	O11—N5—O12—Gd1	0.7 (4)
O1—Gd1—O3—Cu1	−47.02 (19)	O2—Gd1—O12—N5	42.6 (3)
N4—Gd1—O3—Cu1	−123.76 (16)	O9—Gd1—O12—N5	170.3 (3)
N3—Gd1—O3—Cu1	104.2 (3)	O11—Gd1—O12—N5	−0.4 (3)
O2—Gd1—O4—C18	−1.2 (4)	O6—Gd1—O12—N5	−86.9 (3)
O3—Gd1—O4—C18	5.2 (3)	O8—Gd1—O12—N5	141.1 (3)
O9—Gd1—O4—C18	−130.0 (3)	O5—Gd1—O12—N5	−52.2 (4)
O11—Gd1—O4—C18	118.9 (3)	O4—Gd1—O12—N5	−137.4 (3)
O6—Gd1—O4—C18	128.2 (4)	O1—Gd1—O12—N5	82.2 (3)
O8—Gd1—O4—C18	−75.1 (3)	N4—Gd1—O12—N5	157.2 (3)
O5—Gd1—O4—C18	76.2 (3)	N3—Gd1—O12—N5	−70.6 (4)

Experimental details

Crystal data
Chemical formula	[CuGd(C₂₀H₂₂N₂O₄)(NO₃)₃]
M_r	761.22
Crystal system, space group	Monoclinic, P2₁/n
Temperature (K)	223
a, b, c (Å)	11.795 (2), 14.730 (3), 14.892 (3)
β (°)	100.58 (3)
V (Å³)	2543.4 (9)
Z	4
Radiation type	Mo Kα
µ (mm⁻¹)	3.50
Crystal size (mm)	0.56 × 0.13 × 0.13

Data collection
Diffractometer	Rigaku MiniFlexII CCD
Absorption correction	Multi-scan (CrystalClear; Rigaku/MSC, 2002)
T_min, T_max	0.598, 1.000
No. of measured, independent and observed [I > 2σ(I)] reflections	14367, 4460, 4090
R_int	0.032
(sin θ/λ)_max (Å⁻¹)	0.595

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.033, 0.128, 1.20
No. of reflections	4460
No. of parameters	362
No. of restraints	6
H-atom treatment	H-atom parameters constrained
Δρ_max, Δρ_min (e Å⁻³)	2.69, −1.35

Computer programs: CrystalClear (Rigaku/MSC, 2002), SHELXTL (Sheldrick, 2008).

Selected bond lengths (Å) top

Gd1—O1	2.581 (4)	Gd1—O9	2.428 (4)
Gd1—O2	2.336 (3)	Gd1—O11	2.431 (4)
Gd1—O3	2.418 (3)	Gd1—O12	2.520 (3)
Gd1—O4	2.568 (3)	Cu1—O2	1.941 (3)
Gd1—O5	2.472 (5)	Cu1—O3	1.940 (3)
Gd1—O6	2.458 (5)	Cu1—N1	2.004 (4)
Gd1—O8	2.472 (4)	Cu1—N2	1.960 (4)

Acknowledgements

The authors acknowledge the Freshman Research Initiative, funded in part by the HHMI Undergraduate Science Education Award (52005907) and the National Science Foundation (CHE-0629136). Single crystal X-ray data were collected using instrumentation purchased with funds provided by the National Science Foundation (CHE-0741973). BJH wishes to acknowledge the Welch Foundation (F-1631), the Petroleum Research Fund administered by the American Chemical Society (47022-G3), the National Science Foundation (CHE-0639239, CHE-0847763), the American Heart Association (0765078Y), and the UT-CNM and UT-Austin for financial support of this research. RAJ wishes to acknowledge the Welch Foundation (F-816), the Texas Higher Education Coordinating Board (ARP003658–0010-2006) and the Petroleum Research Fund, administered by the American Chemical Society (47014-AC5).

References

Fei, L. & Fang, Z. (2008). Acta Cryst. E64, m406. Web of Science CSD CrossRef IUCr Journals Google Scholar
Rigaku/MSC (2002). CrystalClear. Rigaku/MSC, The Woodlands, Texas, USA. Google Scholar
Sakamoto, M., Manseki, K. & Okawa, H. (2001). Coord. Chem. Rev. 219–221, 379–414. Web of Science CrossRef CAS Google Scholar
Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122. Web of Science CrossRef CAS IUCr Journals Google Scholar
Winpenny, R. E. P. (1998). Chem. Soc. Rev. 27, 447–452. CAS Google Scholar
Xing, J.-C., Wang, J.-H., Yan, P.-F. & Li, G.-M. (2008). Acta Cryst. E64, m1206. Web of Science CSD CrossRef IUCr Journals Google Scholar
Yang, X., Jones, R. A., Lynch, V., Oye, M. M. & Holmes, A. L. (2005). Dalton Trans. pp. 849–851. Web of Science CSD CrossRef Google Scholar

This is an open-access article distributed under the terms of the Creative Commons Attribution (CC-BY) Licence, which permits unrestricted use, distribution, and reproduction in any medium, provided the original authors and source are cited.