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Acta Crystallogr Sect E Struct Rep Online. 2009 September 1; 65(Pt 9): m1121–m1122.
Published online 2009 August 22. doi:  10.1107/S1600536809031742
PMCID: PMC2970067

Bis[μ-2-(2-pyridylmethyl­amino­meth­yl)phenolato]-κ4 N,N′,O:O4 O:N,N′,O-bis­[(thio­cyanato-κN)copper(II)]

Abstract

The centrosymmetric binuclear complex, [Cu2(C13H13N2O)2(NCS)2], formed via phenolate oxygen bridges, involves the CuII atoms in a distorted square-pyramidal coordination [τ = 0.197 (1)]. A Cu(...)Cu separation of 3.2281 (3) Å is observed. The in-plane Cu—Ophenolate distance [1.9342 (8) Å] is shorter than the axial distance [2.252 (8) Å]. The Cu—Namine and Cu—Npy distances are similar [2.0095 (10) and 2.0192 (10) Å, respectively]. The Cu—Nthio­cyanate distance [1.9678 (11) Å] is in the range found for Cu—N distances in previously determined structures containing coordinated thio­cyanate anions. There is an inter­molecular hydrogen bond between the amine H atom and the S atom of a coordinated thio­cyanate anion.

Related literature

For the chemical properties, ligand binding properties and the synthesis of related copper complexes: Kuzmic et al. (1992 [triangle]); Lim et al. (2006 [triangle]); Rogers & Wolf (2002 [triangle]); Sharma et al. (2008 [triangle]); Yisgedu (2001 [triangle]). For related structures, see: Assey et al. (2009 [triangle]); Biswas et al. (2005 [triangle]); Sarkar et al. (2006 [triangle]); Shakya et al. (2006 [triangle]); Wang & Li (2005 [triangle]); You & Zhu (2004 [triangle], 2005 [triangle]); You (2005 [triangle]). For the τ parameter, see: Addison et al. (1984 [triangle]).

An external file that holds a picture, illustration, etc.
Object name is e-65-m1121-scheme1.jpg

Experimental

Crystal data

  • [Cu2(C13H13N2O)2(NCS)2]
  • M r = 669.75
  • Monoclinic, An external file that holds a picture, illustration, etc.
Object name is e-65-m1121-efi1.jpg
  • a = 7.4747 (1) Å
  • b = 16.9237 (3) Å
  • c = 11.0714 (2) Å
  • β = 91.1317 (18)°
  • V = 1400.25 (4) Å3
  • Z = 2
  • Mo Kα radiation
  • μ = 1.71 mm−1
  • T = 200 K
  • 0.44 × 0.37 × 0.28 mm

Data collection

  • Oxford Diffraction Gemini R diffractometer
  • Absorption correction: multi-scan (CrysAlis RED; Oxford Diffraction, 2008 [triangle]) T min = 0.944, T max = 1.000 (expected range = 0.586–0.620)
  • 18586 measured reflections
  • 7024 independent reflections
  • 4611 reflections with I > 2σ(I)
  • R int = 0.026

Refinement

  • R[F 2 > 2σ(F 2)] = 0.029
  • wR(F 2) = 0.071
  • S = 0.89
  • 7024 reflections
  • 181 parameters
  • H-atom parameters constrained
  • Δρmax = 0.44 e Å−3
  • Δρmin = −0.49 e Å−3

Data collection: CrysAlis CCD (Oxford Diffraction, 2008 [triangle]); cell refinement: CrysAlis RED (Oxford Diffraction, 2008 [triangle]); data reduction: CrysAlis RED; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 [triangle]); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 [triangle]); molecular graphics: SHELXTL (Sheldrick, 2008 [triangle]); software used to prepare material for publication: SHELXTL.

Table 1
Selected geometric parameters (Å, °)
Table 2
Hydrogen-bond geometry (Å, °)

Supplementary Material

Crystal structure: contains datablocks I, global. DOI: 10.1107/S1600536809031742/kp2227sup1.cif

Structure factors: contains datablocks I. DOI: 10.1107/S1600536809031742/kp2227Isup2.hkl

Additional supplementary materials: crystallographic information; 3D view; checkCIF report

Acknowledgments

RJB acknowledges the NSF–MRI program (grant CHE-0619278) for funds to purchase the diffractometer.

supplementary crystallographic information

Comment

The synthesis and structure determination of copper complexes containing potentially bridging or ambidentate ligands, such as the thiocyanate anion, is of wide interest. The different possible coordination modes of the thiocyanate anion can involve bridging or ambidentate functions. A major obstacle to a more comprehensive study of thiocyanate polynuclear complexes is the lack of rational synthetic procedures. One convenient synthetic strategy is use displacement of weakly coordinated anions such as perchlorate of trifluoromethanesulfonate. In this instance some control over resulting stereochemistry can be achieved.

The present complex was synthesized by displacement of weakly coordinated perchlorate anions from a structurally determined complex (Assey et al., 2009) The crystal structure of the resulting complex, bis{µ-O-[2-((pyridin-2-ylmethylamino)methyl)phenolato]thiocyanatocopper(II)} has been determined. In this instance, two thiocyanate ligands were ligated to the copper(II) complex as a result of displacement of weakly coordinated perchlorate ligands. This method of ligand substitution has been used in the area of chemical sensors such as: competitive assay method involving the displacement of an indicator ligand (Sharma et al., 2008), fluorescence displacement method involving determination of receptor-ligand binding constants (Kuzmic et al., 1992), luminescence molecular sensing based on analyte coordination to the transition metal complexes (Rogers & Wolf, 2002), and the use of ligand substitution for fluorescence sensing in detection of NO in biological aqueous solution (Lim et al., 2006).

The complex contains a reduced Schiff base, 2-{[(pyridine-2-ylmethyl)amino]methyl}phenolato and thiocyanate coordinated to copper. The phenolate O atoms bridge the two copper centres and the two thiocyanate anions are terminally coordinated to each copper through their N donors (Fig. 1 and Table 1). The resulting complex reveals a centre of inversion. The coordination geometry about each CuII is distorted square pyramidal (τ = 0.197 (1), Addison et al., 1984) with the bridging O, Namine, Npyridine and Nthiocyanate forming the base and a bridging O forming the apex. The Cu—Obase and Cu—Oapex distances are 1.9342 (8) and 2.2526 (8) Å respectively. The Cu—Nthiocyanate distance [1.9678 (11) Å] is in the range observed for other copper(II) complexes containing coordinated thiocyanate (Wang & Li, 2005; You & Zhu, 2004; You, 2005; You & Zhu, 2005). The bond distances to the central copper [Cu—N(1) 2.0095 (10) Å, Cu—N(2) 2.0292 (10) Å, Cu—O 1.9342 (8) Å] are comparable to those observed for related complexes (Shakya et al., 2005) and (Biswas et al., 2005).

Experimental

The complex was synthesized in a three-step process. 1. The ligand (2-pyridylmethyl)(2-hydroxybenzyl)amine (L1H) was synthesized as described below (Yisgedu, 2001). To 5.4 g (50 mmol) of 2-(2-aminomethyl)pyridine in 10 ml of ethanol was added 6.1 g (50 mmol) of salicylaldehyde in 15 ml of ethanol which resulted in a deep yellow colour. The solution was left to stir for 30 m. A sodium borohydride solution (3 g NaBH4, 0.4 g NaOH, and 40.0 ml of H2O) were added dropwise. The solution changed to colourless and was left to stir for 1 h after adding all the NaBH4 solution. The volume of the solution was reduced to 20 ml after extracting three times with chloroform (3 x 40 ml). The extracts were combined and dried in anhydrous Na2SO4 overnight. The Na2SO4 was filtered and the filtrate concentrated to give a colourless oil (9.3 g, 87%).

2. Copper(II) perchlorate precursor complex was synthesized as follows (Yisgedu, 2001): 1.64 g (7.7 mmol) of L1H was mixed with 2.86 g (7.7 mmol) of Cu(ClO4)2.6H2O in 25 ml MeOH and 1.75 ml NaOCH3. The solution mixture was stirred overnight and a green filtrate of precipitate (2.7 g) was obtained. This was washed with EtOH/MeOH (2:1), then crystallized from CH3CN/CH3NO2.

3. Cu(II) thiocyanate complex was synthesized as follows: 0.1 mmol (0.0835 g) of the dinuclear CuII perchlorate complex was dissolved in 15 ml s of EtOH and reacted with 0.25 mmol (0.0203 g) of NaSCN dissolved in 10 ml s EtOH. The mixture was stirred for 18.5 h. A mixture of solids and supernatant were obtained at the end of the reaction. The supernatant was decanted and the solids were re-dissolved in 7.5 ml of DMF, filtered and layered with diethyl ether and left to crystallize. Dark-green crystals suitable for X-ray diffraction were obtained and used for X-ray structure determination.

Refinement

H atoms were placed in geometrically idealized positions and constrained to ride on their parent atoms with C—H distances of 0.95 and 0.99 Å Uiso(H) = 1.2Ueq(C). The H atom attached to N was idealized with an N–H distance of 0.93 Å.

Figures

Fig. 1.
The molecular structure of the dinuclear complex I showing the atom numbering scheme and the 50% probability displacement ellipsoids. The symmetry code for generating the symmetry related dinuclear unit is -x, 1 - y, 1 - z.
Fig. 2.
The molecular packing for I viewed down the a axis.

Crystal data

[Cu2(C13H13N2O)2(NCS)2]F(000) = 684
Mr = 669.75Dx = 1.588 Mg m3
Monoclinic, P21/cMo Kα radiation, λ = 0.71073 Å
a = 7.4747 (1) ÅCell parameters from 7409 reflections
b = 16.9237 (3) Åθ = 4.5–37.4°
c = 11.0714 (2) ŵ = 1.71 mm1
β = 91.1317 (18)°T = 200 K
V = 1400.25 (4) Å3Chunk, dark green
Z = 20.44 × 0.37 × 0.28 mm

Data collection

Oxford Diffraction Gemini R diffractometer7024 independent reflections
Radiation source: fine-focus sealed tube4611 reflections with I > 2σ(I)
graphiteRint = 0.026
Detector resolution: 10.5081 pixels mm-1θmax = 37.5°, θmin = 4.5°
[var phi] and ω scansh = −12→12
Absorption correction: multi-scan (CrysAlis RED; Oxford Diffraction, 2008)k = −28→25
Tmin = 0.944, Tmax = 1.000l = −18→12
18586 measured reflections

Refinement

Refinement on F2Primary atom site location: structure-invariant direct methods
Least-squares matrix: fullSecondary atom site location: difference Fourier map
R[F2 > 2σ(F2)] = 0.029Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.071H-atom parameters constrained
S = 0.89w = 1/[σ2(Fo2) + (0.037P)2] where P = (Fo2 + 2Fc2)/3
7024 reflections(Δ/σ)max = 0.004
181 parametersΔρmax = 0.44 e Å3
0 restraintsΔρmin = −0.49 e Å3

Special details

Experimental. CrysAlis RED, Oxford Diffraction Ltd., Version 1.171.32.15 (release 10-01-2008 CrysAlis171 .NET) (compiled Jan 10 2008,16:37:18) Empirical absorption correction using spherical harmonics, implemented in SCALE3 ABSPACK scaling algorithm.
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 (Å2)

xyzUiso*/Ueq
Cu0.200074 (18)0.530744 (8)0.531057 (12)0.01989 (4)
S0.40414 (4)0.472939 (18)0.13944 (3)0.02856 (7)
O0.07568 (10)0.43052 (4)0.52958 (7)0.02117 (15)
N0.31981 (15)0.51404 (7)0.37642 (10)0.0315 (2)
N10.19612 (12)0.53813 (5)0.71214 (9)0.02082 (18)
H1A0.31460.54070.73900.025*
N20.27182 (13)0.64484 (6)0.55436 (9)0.02351 (19)
C0.35464 (15)0.49643 (7)0.27835 (11)0.0232 (2)
C10.13193 (14)0.37486 (6)0.60789 (10)0.0201 (2)
C20.15668 (15)0.29704 (7)0.56836 (11)0.0243 (2)
H2A0.12560.28320.48750.029*
C30.22630 (16)0.23993 (7)0.64630 (12)0.0286 (3)
H3A0.24150.18730.61850.034*
C40.27368 (17)0.25921 (8)0.76442 (12)0.0314 (3)
H4A0.32710.22080.81630.038*
C50.24208 (16)0.33520 (7)0.80592 (11)0.0271 (2)
H5A0.27220.34830.88730.033*
C60.16704 (15)0.39265 (7)0.73042 (10)0.0216 (2)
C70.11123 (16)0.47201 (6)0.77868 (11)0.0238 (2)
H7A−0.02050.47700.77160.029*
H7B0.14530.47560.86540.029*
C80.11526 (16)0.61569 (7)0.73720 (11)0.0253 (2)
H8A0.13730.63050.82270.030*
H8B−0.01560.61360.72200.030*
C90.19939 (15)0.67555 (6)0.65499 (11)0.0232 (2)
C100.20102 (17)0.75594 (7)0.67794 (12)0.0293 (3)
H10A0.14780.77660.74850.035*
C110.28194 (18)0.80584 (7)0.59583 (14)0.0351 (3)
H11A0.28360.86130.60910.042*
C120.35985 (17)0.77426 (7)0.49476 (13)0.0330 (3)
H12A0.41800.80750.43860.040*
C130.35215 (17)0.69330 (7)0.47618 (12)0.0287 (2)
H13A0.40510.67150.40630.034*

Atomic displacement parameters (Å2)

U11U22U33U12U13U23
Cu0.02292 (7)0.01935 (6)0.01741 (7)−0.00059 (5)0.00062 (5)−0.00060 (5)
S0.03068 (15)0.03244 (15)0.02262 (15)0.00118 (12)0.00194 (11)−0.00631 (12)
O0.0239 (4)0.0196 (3)0.0198 (4)0.0005 (3)−0.0051 (3)0.0021 (3)
N0.0326 (6)0.0367 (6)0.0256 (5)−0.0008 (4)0.0074 (4)−0.0037 (4)
N10.0204 (4)0.0215 (4)0.0205 (5)0.0007 (3)−0.0009 (3)−0.0009 (3)
N20.0214 (4)0.0230 (4)0.0260 (5)−0.0020 (3)−0.0025 (4)0.0003 (4)
C0.0199 (5)0.0226 (5)0.0271 (6)0.0003 (4)0.0010 (4)0.0003 (4)
C10.0180 (4)0.0210 (5)0.0215 (5)0.0000 (4)0.0004 (4)0.0033 (4)
C20.0268 (5)0.0218 (5)0.0243 (6)0.0014 (4)0.0018 (4)0.0008 (4)
C30.0298 (6)0.0207 (5)0.0356 (7)0.0043 (4)0.0055 (5)0.0048 (5)
C40.0310 (6)0.0296 (6)0.0336 (7)0.0067 (5)0.0014 (5)0.0138 (5)
C50.0282 (6)0.0311 (6)0.0219 (6)0.0002 (5)−0.0026 (4)0.0068 (5)
C60.0216 (5)0.0229 (5)0.0204 (5)−0.0007 (4)−0.0002 (4)0.0041 (4)
C70.0284 (5)0.0253 (5)0.0176 (5)−0.0001 (4)0.0024 (4)0.0015 (4)
C80.0280 (6)0.0230 (5)0.0249 (6)0.0006 (4)0.0024 (4)−0.0056 (4)
C90.0223 (5)0.0223 (5)0.0249 (6)0.0002 (4)−0.0045 (4)−0.0026 (4)
C100.0313 (6)0.0236 (5)0.0329 (7)0.0002 (5)−0.0042 (5)−0.0055 (5)
C110.0353 (7)0.0211 (5)0.0484 (9)−0.0039 (5)−0.0095 (6)−0.0004 (5)
C120.0302 (6)0.0279 (6)0.0405 (8)−0.0065 (5)−0.0043 (5)0.0071 (5)
C130.0270 (5)0.0294 (6)0.0297 (7)−0.0040 (5)0.0000 (5)0.0036 (5)

Geometric parameters (Å, °)

Cu—O1.9342 (8)C3—H3A0.9500
Cu—N1.9678 (11)C4—C51.3874 (18)
Cu—N12.0095 (10)C4—H4A0.9500
Cu—N22.0192 (10)C5—C61.3929 (16)
Cu—Oi2.2526 (8)C5—H5A0.9500
S—C1.6378 (12)C6—C71.5073 (16)
O—C11.3421 (13)C7—H7A0.9900
O—Cui2.2526 (8)C7—H7B0.9900
N—C1.1605 (16)C8—C91.5076 (16)
N1—C81.4737 (14)C8—H8A0.9900
N1—C71.4886 (14)C8—H8B0.9900
N1—H1A0.9300C9—C101.3840 (16)
N2—C131.3427 (15)C10—C111.3882 (19)
N2—C91.3521 (15)C10—H10A0.9500
C1—C21.4012 (15)C11—C121.379 (2)
C1—C61.4092 (16)C11—H11A0.9500
C2—C31.3900 (17)C12—C131.3865 (18)
C2—H2A0.9500C12—H12A0.9500
C3—C41.387 (2)C13—H13A0.9500
O—Cu—N95.37 (4)C5—C4—H4A120.4
O—Cu—N192.66 (3)C4—C5—C6121.16 (12)
N—Cu—N1153.23 (5)C4—C5—H5A119.4
O—Cu—N2165.03 (4)C6—C5—H5A119.4
N—Cu—N297.14 (4)C5—C6—C1119.59 (11)
N1—Cu—N279.76 (4)C5—C6—C7121.35 (11)
O—Cu—Oi79.39 (3)C1—C6—C7118.94 (10)
N—Cu—Oi102.22 (4)N1—C7—C6111.76 (9)
N1—Cu—Oi104.35 (3)N1—C7—H7A109.3
N2—Cu—Oi89.94 (3)C6—C7—H7A109.3
C1—O—Cu117.75 (7)N1—C7—H7B109.3
C1—O—Cui132.06 (7)C6—C7—H7B109.3
Cu—O—Cui100.61 (3)H7A—C7—H7B107.9
C—N—Cu164.84 (11)N1—C8—C9107.90 (9)
C8—N1—C7113.33 (9)N1—C8—H8A110.1
C8—N1—Cu104.92 (7)C9—C8—H8A110.1
C7—N1—Cu117.50 (7)N1—C8—H8B110.1
C8—N1—H1A106.8C9—C8—H8B110.1
C7—N1—H1A106.8H8A—C8—H8B108.4
Cu—N1—H1A106.8N2—C9—C10121.79 (11)
C13—N2—C9119.20 (10)N2—C9—C8114.69 (9)
C13—N2—Cu128.51 (9)C10—C9—C8123.50 (11)
C9—N2—Cu111.30 (7)C9—C10—C11118.70 (12)
N—C—S179.16 (12)C9—C10—H10A120.7
O—C1—C2119.97 (10)C11—C10—H10A120.7
O—C1—C6121.46 (10)C12—C11—C10119.47 (12)
C2—C1—C6118.57 (10)C12—C11—H11A120.3
C3—C2—C1120.65 (12)C10—C11—H11A120.3
C3—C2—H2A119.7C11—C12—C13119.10 (12)
C1—C2—H2A119.7C11—C12—H12A120.5
C4—C3—C2120.48 (12)C13—C12—H12A120.5
C4—C3—H3A119.8N2—C13—C12121.71 (12)
C2—C3—H3A119.8N2—C13—H13A119.1
C3—C4—C5119.23 (11)C12—C13—H13A119.1
C3—C4—H4A120.4
N—Cu—O—C1108.23 (8)Cui—O—C1—C6−92.44 (11)
N1—Cu—O—C1−46.20 (8)O—C1—C2—C3175.63 (10)
N2—Cu—O—C1−105.16 (15)C6—C1—C2—C3−4.46 (16)
Oi—Cu—O—C1−150.31 (9)C1—C2—C3—C4−0.47 (18)
N—Cu—O—Cui−101.46 (4)C2—C3—C4—C53.37 (18)
N1—Cu—O—Cui104.11 (4)C3—C4—C5—C6−1.27 (19)
N2—Cu—O—Cui45.15 (15)C4—C5—C6—C1−3.70 (18)
Oi—Cu—O—Cui0.0C4—C5—C6—C7172.27 (11)
O—Cu—N—C37.5 (4)O—C1—C6—C5−173.61 (10)
N1—Cu—N—C144.3 (4)C2—C1—C6—C56.48 (16)
N2—Cu—N—C−134.3 (4)O—C1—C6—C710.32 (15)
Oi—Cu—N—C−42.8 (4)C2—C1—C6—C7−169.59 (10)
O—Cu—N1—C8−126.33 (7)C8—N1—C7—C6166.99 (10)
N—Cu—N1—C8126.22 (10)Cu—N1—C7—C644.27 (12)
N2—Cu—N1—C840.68 (7)C5—C6—C7—N1125.30 (11)
Oi—Cu—N1—C8−46.61 (7)C1—C6—C7—N1−58.71 (14)
O—Cu—N1—C70.59 (8)C7—N1—C8—C9−174.09 (9)
N—Cu—N1—C7−106.86 (11)Cu—N1—C8—C9−44.65 (10)
N2—Cu—N1—C7167.59 (8)C13—N2—C9—C101.96 (17)
Oi—Cu—N1—C780.31 (8)Cu—N2—C9—C10−167.62 (9)
O—Cu—N2—C13−137.76 (14)C13—N2—C9—C8−179.11 (10)
N—Cu—N2—C138.72 (11)Cu—N2—C9—C811.31 (12)
N1—Cu—N2—C13161.81 (11)N1—C8—C9—N222.59 (14)
Oi—Cu—N2—C13−93.59 (10)N1—C8—C9—C10−158.50 (11)
O—Cu—N2—C930.60 (19)N2—C9—C10—C11−1.00 (19)
N—Cu—N2—C9177.08 (8)C8—C9—C10—C11−179.83 (12)
N1—Cu—N2—C9−29.83 (8)C9—C10—C11—C12−0.7 (2)
Oi—Cu—N2—C974.77 (8)C10—C11—C12—C131.4 (2)
Cu—N—C—S117 (8)C9—N2—C13—C12−1.24 (18)
Cu—O—C1—C2−133.51 (9)Cu—N2—C13—C12166.32 (10)
Cui—O—C1—C287.46 (12)C11—C12—C13—N2−0.4 (2)
Cu—O—C1—C646.58 (12)

Symmetry codes: (i) −x, −y+1, −z+1.

Hydrogen-bond geometry (Å, °)

D—H···AD—HH···AD···AD—H···A
N1—H1A···Sii0.932.483.3866 (10)164

Symmetry codes: (ii) −x+1, −y+1, −z+1.

Footnotes

Supplementary data and figures for this paper are available from the IUCr electronic archives (Reference: KP2227).

References

  • Addison, A. W., Rao, T. N., Reedijk, J., van Rijn, J. & Verschoor, G. C. (1984). J. Chem. Soc. Dalton Trans. pp. 1349–1356.
  • Assey, G. E., Yisgedu, T., Gultneh, Y., Butcher, R. J. & Tesema, Y. (2009). Acta Cryst. E65, m1007–m1008. [PMC free article] [PubMed]
  • Biswas, S., Mitra, K., Chattopadhyay, S. K., Adhikary, B. & Lucas, C. R. (2005). Transition Met. Chem.30, 393–398.
  • Kuzmic, P., Moss, M. L., Kofron, J. L. & Rich, D. H. (1992). Anal. Biochem.205, 65–69. [PubMed]
  • Lim, M. H., Wong, B. A., Pitcock, W. H. Jr, Mokshagundam, D., Baik, M.-H. & Lippard, S. J. (2006). J. Am. Chem. Soc.128, 14364–14373. [PubMed]
  • Oxford Diffraction (2008). CrysAlis CCD and CrysAlis RED Oxford Diffraction Ltd, Yarnton, England.
  • Rogers, C. W. & Wolf, M. O. (2002). Coord. Chem. Rev.233–234, 341–350.
  • Sarkar S., Mondal, A., Chopra, D., Ribas, J. & Rajak, K. K. (2006). Eur. J. Inorg. Chem. pp. 3510–3516.
  • Shakya, R., Imbert, C., Hratchian, H. P., Lanzanaster, M., Heeg, M. J., McGarvey, B. R., Allard, M., Schlegel, H. B. & Viran, C. N. (2006). Dalton Trans. pp. 2517–2525. [PubMed]
  • Sharma, J., Besanger, T. R. & Brennan, J. D. (2008). Anal. Chem.80, 3213–3220. [PubMed]
  • Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122. [PubMed]
  • Wang, N. & Li, J.-P. (2005). Acta Cryst. E61, m1223–m1225.
  • Yisgedu, T. B. (2001). PhD dissertation, Howard University, Washington, DC, USA.
  • You, Z.-L. (2005). Acta Cryst. C61, m466–m468. [PubMed]
  • You, Z.-L. & Zhu, H.-L. (2004). Z. Anorg. Allg. Chem.630, 2754–2760.
  • You, Z.-L. & Zhu, H.-L. (2005). Acta Cryst. C61, m421–m423. [PubMed]

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