Bis(4-amino­pyridinium) tetra­chlorido­cobaltate(II)

Jebas, S.R.; Sinthiya, A.; Ravindran Durai Nayagam, B.; Schollmeyer, D.; Raj, S.A.C.

doi:10.1107/S1600536809013270

metal-organic compounds

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ISSN: 2056-9890

Volume 65| Part 5| May 2009| Page m521

doi:10.1107/S1600536809013270

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Bis(4-aminopyridinium) tetrachloridocobaltate(II)

Samuel Robinson Jebas,^a ^* A. Sinthiya,^b B. Ravindran Durai Nayagam,^c Dieter Schollmeyer ^d and S. Alfred Cecil Raj ^e

^aDepartment of Physics, Karunya University, Karunya Nagar, Coimbatore 641 114, India, ^bDepartment of Electronics, St. Josephs College, Tiruchirappalli 620 002, India, ^cDepartment of Chemistry, Popes College, Sawyerpuram 628 251, Tamilnadu, India, ^dInstitut für Organische Chemie, Universität Mainz, Duesbergweg 10-14, 55099 Mainz, Germany, and ^eDepartment of Physics, St. Josephs College, Tiruchirappalli 620 002, India
^*Correspondence e-mail: jebas2@gmail.com

(Received 5 April 2009; accepted 7 April 2009; online 18 April 2009)

In the title compound, (C₅H₇N₂)₂[CoCl₄], the cobalt(II) ion is coordinated by four chloride ions in a slightly distorted tetrahedral geometry. The crystal packing is stabilized by intermolecular N—H⋯Cl hydrogen bonding, forming a three-dimensional network. The crystal was a non-merohedral twin emulating tetragonal symmetry, but being in fact orthorhombic.

Related literature

For the biological activity of 4-aminopyridine, see: Judge & Bever (2006 ); Schwid et al. (1997 ); Strupp et al. (2004 ). For related structures, see: Anderson et al. (2005 ); Chao & Schempp (1977 ); Jebas et al. (2006 ); Zhang et al. (2005 ). For bond-length data, see: Anderson et al. (2005).

Experimental

Crystal data

(C₅H₇N₂)₂[CoCl₄]
M_r = 390.98
Orthorhombic, P 2₁ 2₁ 2₁
a = 15.0051 (12) Å
b = 14.9751 (12) Å
c = 7.1723 (6) Å
V = 1611.6 (2) Å³
Z = 4
Mo Kα radiation
μ = 1.72 mm⁻¹
T = 173 K
0.25 × 0.22 × 0.17 mm

Data collection

Bruker APEXII SMART CCD diffractometer
Absorption correction: multi-scan (SADABS; Bruker, 2008 ) T_min = 0.650, T_max = 0.746
45299 measured reflections
3884 independent reflections
3802 reflections with I > 2σ(I)
R_int = 0.035

Refinement

R[F² > 2σ(F²)] = 0.021
wR(F²) = 0.052
S = 1.02
3884 reflections
173 parameters
H-atom parameters constrained
Δρ_max = 0.25 e Å⁻³
Δρ_min = −0.13 e Å⁻³
Absolute structure: Flack (1983 ), 1654 Friedel pairs
Flack parameter: −0.12 (2)

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
N4—H4⋯Cl2ⁱ	0.88	2.94	3.563 (3)	130
N4—H4⋯Cl3ⁱ	0.88	2.67	3.335 (3)	134
N7—H7A⋯Cl2ⁱⁱ	0.84	2.50	3.338 (2)	175
N7—H7B⋯Cl1	0.90	2.53	3.387 (2)	158
N11—H11⋯Cl1ⁱⁱⁱ	0.87	2.52	3.272 (3)	144
N14—H14B⋯Cl2^iv	0.84	2.64	3.394 (3)	149
N14—H14A⋯Cl4	0.90	2.42	3.303 (2)	169
Symmetry codes: (i) $[-x+{\script{1\over 2}}, -y, z-{\script{1\over 2}}]$ ; (ii) $[x-{\script{1\over 2}}, -y+{\script{1\over 2}}, -z+1]$ ; (iii) $[x-{\script{1\over 2}}, -y+{\script{1\over 2}}, -z]$ ; (iv) $[-x+1, y+{\script{1\over 2}}, -z+{\script{1\over 2}}]$ .

Data collection: APEX2 (Bruker, 2008); cell refinement: SAINT (Bruker, 2008); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: SHELXTL (Sheldrick, 2008); software used to prepare material for publication: SHELXTL and PLATON (Spek, 2009 ).

Supporting information

Crystal structure: contains datablocks global, I. DOI: 10.1107/S1600536809013270/bt2925sup1.cif

Structure factors: contains datablock I. DOI: 10.1107/S1600536809013270/bt2925Isup2.hkl

checkCIF report

Comment top

4-aminopyridine (Fampridine) is used clinically in Lambert-Eaton myasthenic syndrome and multiple sclerosis because by blocking potassium channels it prolongs action potentials thereby increasing transmitter release at the neuromuscular junction (Judge & Bever, 2006; Schwid et al., 1997; Strupp et al., 2004). The structure of 4-aminopyridine has been reported (Chao & Schempp, 1977). Redetermination of the structure of 4-aminopyridine has been reported (Anderson et al., 2005). As a part of our investigation of the reactions of the 4-aminopyridine with metals, we report here the crystal structure of the title compound (I).

The asymmetric unit of (I), consists of two molecules of 4-aminopyridinium cation and a [CoCl₄]^2- anion. The bond lengths and bond angles of the 4-aminopyridinium are comparable with the values reported earlier for the 4-aminopyridine in the its uncomplexed form (Anderson et al., 2005; Chao & Schempp, 1977). Protonation of the atoms N4 and N11 of the 4-aminopyridine leads to the widening of C3–N4–C5 and C10–N11–C12 angles in the pyridine ring to 121.3 (7)° and 120.4 (7)°, compared to 115.25 (13)° in 4-aminopyridine (Anderson et al., 2005). The 4-aminopyridine ring is essentially planar with the maximum deviation from planarity of 0.014 (3) Å for the atoms C8 and N11 respectively.

The anion exhibits distorted tetraedral geometry, with the Co^II ion is surrounded by four Cl atoms, with Cl—Co—Cl angles ranging from 106.19 (11)–115.63 (8) Å. The mean Co—Cl bond length, 2.2707 (2) Å, is close to those observed in similar complex (Jebas et al., 2006; Zhang et al., 2005).

The crystal packing (Fig. 2) is consolidated by intermolecular N—H···Cl hydrogen bonding to form a three dimensional network.

Related literature top

For the biological activity of 4-aminopyridine, see: Judge & Bever (2006); Schwid et al. (1997); Strupp et al. (2004). For related structures, see: Anderson et al. (2005); Chao & Schempp (1977); Jebas et al. (2006); Zhang et al. (2005). For bond-length data, see: Anderson et al. (2005).

Experimental top

4-aminopyridine (0.094 g, 1 mmol) and and CoCl₂ (0.169 g, 1 mmol) in ethanol (10 ml each) and the solution was stirred well for 3 h. Blue crystals of (I) were obtained by slow evaporation of the solution over a period of one month.

Computing details top

Data collection: APEX2 (Bruker, 2008); cell refinement: SAINT (Bruker, 2008); data reduction: SAINT (Bruker, 2008); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: SHELXTL (Sheldrick, 2008); software used to prepare material for publication: SHELXTL (Sheldrick, 2008) and PLATON (Spek, 2009).

Figures top

	Fig. 1. The molecular structure of the title compound, showing 50% probability displacement ellipsoids and the atom numbering scheme. Intramolecular hydrogen bondings are shown as dashed lines.
	Fig. 2. The crystal packing of the title compound, viewed down the a axis, showing the three dimensional network.

Bis(4-aminopyridinium) tetrachloridocobalt(II) top

Crystal data top

(C₅H₇N₂)₂[CoCl₄]	F(000) = 788
M_r = 390.98	D_x = 1.611 Mg m⁻³
Orthorhombic, P2₁2₁2₁	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: P 2ac 2ab	Cell parameters from 9192 reflections
a = 15.0051 (12) Å	θ = 2.7–27.8°
b = 14.9751 (12) Å	µ = 1.72 mm⁻¹
c = 7.1723 (6) Å	T = 173 K
V = 1611.6 (2) Å³	Block, blue
Z = 4	0.25 × 0.22 × 0.17 mm

Data collection top

Bruker APEXII SMART CCD diffractometer	3884 independent reflections
Radiation source: sealed Tube	3802 reflections with I > 2σ(I)
Graphite monochromator	R_int = 0.035
CCD scan	θ_max = 28.0°, θ_min = 1.4°
Absorption correction: multi-scan (SADABS; Bruker, 2008)	h = −19→19
T_min = 0.650, T_max = 0.746	k = −19→19
45299 measured reflections	l = −9→9

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)] = 0.021	H-atom parameters constrained
wR(F²) = 0.052	w = 1/[σ²(F_o²) + (0.0281P)² + 0.361P] where P = (F_o² + 2F_c²)/3
S = 1.02	(Δ/σ)_max < 0.001
3884 reflections	Δρ_max = 0.25 e Å⁻³
173 parameters	Δρ_min = −0.13 e Å⁻³
0 restraints	Absolute structure: Flack (1983), 1654 Friedel pairs
Primary atom site location: structure-invariant direct methods	Absolute structure parameter: −0.12 (2)

Crystal data top

(C₅H₇N₂)₂[CoCl₄]	V = 1611.6 (2) Å³
M_r = 390.98	Z = 4
Orthorhombic, P2₁2₁2₁	Mo Kα radiation
a = 15.0051 (12) Å	µ = 1.72 mm⁻¹
b = 14.9751 (12) Å	T = 173 K
c = 7.1723 (6) Å	0.25 × 0.22 × 0.17 mm

Data collection top

Bruker APEXII SMART CCD diffractometer	3884 independent reflections
Absorption correction: multi-scan (SADABS; Bruker, 2008)	3802 reflections with I > 2σ(I)
T_min = 0.650, T_max = 0.746	R_int = 0.035
45299 measured reflections

Refinement top

R[F² > 2σ(F²)] = 0.021	H-atom parameters constrained
wR(F²) = 0.052	Δρ_max = 0.25 e Å⁻³
S = 1.02	Δρ_min = −0.13 e Å⁻³
3884 reflections	Absolute structure: Flack (1983), 1654 Friedel pairs
173 parameters	Absolute structure parameter: −0.12 (2)
0 restraints

Special details top

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. Structure was refined as tetragonal twin with basf=0.34063

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

	x	y	z	U_iso*/U_eq
Co1	0.49922 (2)	0.24481 (2)	0.37955 (6)	0.02580 (7)
Cl1	0.45208 (4)	0.12712 (5)	0.20160 (11)	0.03485 (16)
Cl2	0.59477 (5)	0.18722 (5)	0.59594 (11)	0.03872 (17)
Cl3	0.38406 (6)	0.30281 (5)	0.54058 (11)	0.04194 (19)
Cl4	0.56931 (5)	0.33990 (5)	0.18373 (14)	0.04232 (17)
C1	0.19394 (17)	0.06484 (18)	0.2826 (4)	0.0289 (5)
C2	0.2459 (2)	−0.0132 (2)	0.2552 (4)	0.0337 (6)
H2	0.3091	−0.0095	0.2540	0.040*
C3	0.2050 (2)	−0.0935 (2)	0.2307 (4)	0.0379 (7)
H3	0.2400	−0.1455	0.2116	0.045*
N4	0.11624 (18)	−0.10010 (17)	0.2331 (3)	0.0413 (6)
H4	0.0873	−0.1508	0.2248	0.050*
C5	0.0644 (2)	−0.0280 (2)	0.2604 (4)	0.0403 (7)
H5	0.0015	−0.0348	0.2631	0.048*
C6	0.10048 (18)	0.0545 (2)	0.2843 (4)	0.0342 (6)
H6	0.0630	0.1049	0.3021	0.041*
N7	0.23233 (15)	0.14446 (15)	0.3030 (4)	0.0382 (5)
H7A	0.2002	0.1883	0.3330	0.057*
H7B	0.2909	0.1553	0.2895	0.057*
C8	0.32310 (18)	0.44022 (18)	0.0283 (4)	0.0289 (5)
C9	0.3084 (2)	0.34727 (18)	0.0205 (4)	0.0326 (6)
H9	0.3562	0.3066	0.0389	0.039*
C10	0.2245 (2)	0.3171 (2)	−0.0139 (4)	0.0398 (7)
H10	0.2142	0.2546	−0.0204	0.048*
N11	0.15584 (17)	0.37337 (19)	−0.0389 (3)	0.0418 (6)
H11	0.1000	0.3568	−0.0377	0.050*
C12	0.1679 (2)	0.4632 (2)	−0.0254 (4)	0.0382 (7)
H12	0.1183	0.5021	−0.0385	0.046*
C13	0.24960 (17)	0.4974 (3)	0.0064 (4)	0.0331 (6)
H13	0.2575	0.5602	0.0140	0.040*
N14	0.40431 (15)	0.47315 (16)	0.0593 (3)	0.0375 (5)
H14A	0.4522	0.4383	0.0767	0.056*
H14B	0.4130	0.5288	0.0656	0.056*

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
Co1	0.02267 (19)	0.0223 (2)	0.03247 (13)	0.00081 (16)	−0.00149 (13)	−0.00034 (12)
Cl1	0.0261 (3)	0.0370 (4)	0.0415 (4)	−0.0058 (2)	0.0005 (3)	−0.0129 (3)
Cl2	0.0389 (4)	0.0279 (3)	0.0493 (4)	0.0002 (2)	−0.0190 (3)	0.0004 (3)
Cl3	0.0407 (4)	0.0315 (4)	0.0536 (4)	0.0119 (3)	0.0134 (3)	0.0012 (3)
Cl4	0.0296 (3)	0.0346 (4)	0.0628 (4)	−0.0003 (3)	0.0073 (3)	0.0151 (3)
C1	0.0278 (13)	0.0327 (14)	0.0263 (13)	0.0030 (10)	−0.0015 (11)	0.0023 (11)
C2	0.0296 (15)	0.0333 (15)	0.0383 (15)	0.0032 (11)	0.0010 (11)	0.0018 (13)
C3	0.0486 (17)	0.0302 (14)	0.0349 (15)	0.0031 (12)	−0.0027 (13)	−0.0019 (11)
N4	0.0536 (15)	0.0364 (13)	0.0338 (12)	−0.0155 (11)	−0.0055 (11)	0.0029 (10)
C5	0.0334 (16)	0.0515 (17)	0.0359 (15)	−0.0080 (13)	−0.0017 (12)	0.0069 (12)
C6	0.0289 (14)	0.0408 (16)	0.0329 (14)	0.0033 (11)	−0.0021 (12)	0.0026 (12)
N7	0.0303 (11)	0.0273 (12)	0.0570 (15)	0.0018 (8)	0.0002 (11)	0.0017 (11)
C8	0.0279 (13)	0.0328 (13)	0.0261 (12)	0.0014 (10)	0.0004 (11)	0.0015 (11)
C9	0.0403 (15)	0.0260 (13)	0.0317 (13)	0.0018 (11)	0.0001 (12)	0.0001 (11)
C10	0.0500 (17)	0.0372 (17)	0.0321 (14)	−0.0146 (14)	0.0024 (13)	−0.0031 (12)
N11	0.0305 (12)	0.0627 (17)	0.0322 (11)	−0.0136 (12)	−0.0010 (10)	−0.0001 (12)
C12	0.0342 (15)	0.0499 (18)	0.0304 (14)	0.0011 (12)	0.0018 (12)	0.0038 (13)
C13	0.0307 (14)	0.0327 (16)	0.0357 (14)	0.0041 (10)	0.0040 (13)	0.0027 (11)
N14	0.0279 (11)	0.0295 (11)	0.0550 (15)	−0.0007 (8)	−0.0018 (11)	−0.0008 (10)

Geometric parameters (Å, º) top

Co1—Cl3	2.2527 (8)	N7—H7A	0.8422
Co1—Cl4	2.2597 (8)	N7—H7B	0.8984
Co1—Cl2	2.2822 (8)	C8—N14	1.333 (3)
Co1—Cl1	2.2880 (8)	C8—C13	1.405 (4)
C1—N7	1.332 (3)	C8—C9	1.410 (4)
C1—C6	1.411 (4)	C9—C10	1.360 (4)
C1—C2	1.419 (4)	C9—H9	0.9500
C2—C3	1.361 (4)	C10—N11	1.344 (4)
C2—H2	0.9500	C10—H10	0.9500
C3—N4	1.335 (4)	N11—C12	1.360 (4)
C3—H3	0.9500	N11—H11	0.8737
N4—C5	1.345 (4)	C12—C13	1.348 (4)
N4—H4	0.8772	C12—H12	0.9500
C5—C6	1.359 (4)	C13—H13	0.9500
C5—H5	0.9500	N14—H14A	0.8967
C6—H6	0.9500	N14—H14B	0.8440

Cl3—Co1—Cl4	115.64 (3)	C1—N7—H7A	118.5
Cl3—Co1—Cl2	106.20 (4)	C1—N7—H7B	124.9
Cl4—Co1—Cl2	111.62 (3)	H7A—N7—H7B	116.6
Cl3—Co1—Cl1	110.24 (3)	N14—C8—C13	120.7 (3)
Cl4—Co1—Cl1	106.41 (4)	N14—C8—C9	121.0 (2)
Cl2—Co1—Cl1	106.41 (3)	C13—C8—C9	118.3 (3)
N7—C1—C6	121.8 (2)	C10—C9—C8	118.7 (3)
N7—C1—C2	121.0 (3)	C10—C9—H9	120.7
C6—C1—C2	117.2 (3)	C8—C9—H9	120.7
C3—C2—C1	119.8 (3)	N11—C10—C9	121.7 (3)
C3—C2—H2	120.1	N11—C10—H10	119.1
C1—C2—H2	120.1	C9—C10—H10	119.1
N4—C3—C2	121.0 (3)	C10—N11—C12	120.6 (3)
N4—C3—H3	119.5	C10—N11—H11	123.8
C2—C3—H3	119.5	C12—N11—H11	114.0
C3—N4—C5	121.2 (3)	C13—C12—N11	120.6 (3)
C3—N4—H4	123.8	C13—C12—H12	119.7
C5—N4—H4	114.8	N11—C12—H12	119.7
N4—C5—C6	121.2 (3)	C12—C13—C8	120.1 (3)
N4—C5—H5	119.4	C12—C13—H13	120.0
C6—C5—H5	119.4	C8—C13—H13	120.0
C5—C6—C1	119.6 (3)	C8—N14—H14A	122.7
C5—C6—H6	120.2	C8—N14—H14B	121.0
C1—C6—H6	120.2	H14A—N14—H14B	116.3

N7—C1—C2—C3	−178.6 (3)	N14—C8—C9—C10	−179.2 (3)
C6—C1—C2—C3	0.5 (4)	C13—C8—C9—C10	2.2 (4)
C1—C2—C3—N4	−0.4 (4)	C8—C9—C10—N11	−0.5 (4)
C2—C3—N4—C5	−0.2 (5)	C9—C10—N11—C12	−1.8 (4)
C3—N4—C5—C6	0.8 (4)	C10—N11—C12—C13	2.5 (5)
N4—C5—C6—C1	−0.7 (4)	N11—C12—C13—C8	−0.8 (4)
N7—C1—C6—C5	179.1 (3)	N14—C8—C13—C12	179.8 (3)
C2—C1—C6—C5	0.0 (4)	C9—C8—C13—C12	−1.5 (4)

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
N4—H4···Cl2ⁱ	0.88	2.94	3.563 (3)	130
N4—H4···Cl3ⁱ	0.88	2.67	3.335 (3)	134
N7—H7A···Cl2ⁱⁱ	0.84	2.50	3.338 (2)	175
N7—H7B···Cl1	0.90	2.53	3.387 (2)	158
N11—H11···Cl1ⁱⁱⁱ	0.87	2.52	3.272 (3)	144
N14—H14B···Cl2^iv	0.84	2.64	3.394 (3)	149
N14—H14A···Cl4	0.90	2.42	3.303 (2)	169

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

Experimental details

Crystal data
Chemical formula	(C₅H₇N₂)₂[CoCl₄]
M_r	390.98
Crystal system, space group	Orthorhombic, P2₁2₁2₁
Temperature (K)	173
a, b, c (Å)	15.0051 (12), 14.9751 (12), 7.1723 (6)
V (Å³)	1611.6 (2)
Z	4
Radiation type	Mo Kα
µ (mm⁻¹)	1.72
Crystal size (mm)	0.25 × 0.22 × 0.17

Data collection
Diffractometer	Bruker APEXII SMART CCD diffractometer
Absorption correction	Multi-scan (SADABS; Bruker, 2008)
T_min, T_max	0.650, 0.746
No. of measured, independent and observed [I > 2σ(I)] reflections	45299, 3884, 3802
R_int	0.035
(sin θ/λ)_max (Å⁻¹)	0.660

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.021, 0.052, 1.02
No. of reflections	3884
No. of parameters	173
H-atom treatment	H-atom parameters constrained
Δρ_max, Δρ_min (e Å⁻³)	0.25, −0.13
Absolute structure	Flack (1983), 1654 Friedel pairs
Absolute structure parameter	−0.12 (2)

Computer programs: APEX2 (Bruker, 2008), SAINT (Bruker, 2008), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), SHELXTL (Sheldrick, 2008) and PLATON (Spek, 2009).

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
N4—H4···Cl2ⁱ	0.88	2.94	3.563 (3)	130
N4—H4···Cl3ⁱ	0.88	2.67	3.335 (3)	134
N7—H7A···Cl2ⁱⁱ	0.84	2.50	3.338 (2)	175
N7—H7B···Cl1	0.90	2.53	3.387 (2)	158
N11—H11···Cl1ⁱⁱⁱ	0.87	2.52	3.272 (3)	144
N14—H14B···Cl2^iv	0.84	2.64	3.394 (3)	149
N14—H14A···Cl4	0.90	2.42	3.303 (2)	169

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

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Volume 65| Part 5| May 2009| Page m521

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