1-[(E)-Anthracen-9-yl­methyl­idene]-2-(2,4-di­nitro­phen­yl)hydrazine

A. e Silva, J. de; Yuste-Vivas, C.; Sobral, A.J.F.N.; Silva, M.R.

doi:10.1107/S1600536813009197

organic compounds

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ISSN: 2056-9890

Volume 69| Part 5| May 2013| Page o705

https://doi.org/10.1107/S1600536813009197

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1-[(E)-Anthracen-9-ylmethylidene]-2-(2,4-dinitrophenyl)hydrazine

Joana de A. e Silva,^a Consuelo Yuste-Vivas,^b ^* Abilio J. F. N. Sobral ^a and Manuela Ramos Silva ^b

^aChemistry Department, University of Coimbra, P-3004-530 Coimbra, Portugal, and ^bCEMDRX, Physics Department, University of Coimbra, P-3004-516 Coimbra, Portugal
^*Correspondence e-mail: xelo@teor.fis.uc.pt

(Received 15 February 2013; accepted 4 April 2013; online 13 April 2013)

In the title Schiff base, C₂₁H₁₄N₄O₄, the dihedral angle between the two nitro groups and the central benzene ring are 83.6 (5) and 2.6 (6)°. The anthracene ring system and the benzene ring make a dihedral angle of 0.7 (2)°. Intramolecular N—H⋯O and C—H⋯N hydrogen bonds occur. In the crystal, C—H⋯O hydrogen bonds link the molecules, forming chains along the b-axis direction.

Related literature

For general background to hydrazone derivatives, see: Kahwa et al. (1986 ). For the structures of 2,4-dinitrophenylhydrazine and 9-anthraldehyde, see: Okabe et al. (1993 ) and Trotter (1959 ), respectively.

Experimental

Crystal data

C₂₁H₁₄N₄O₄
M_r = 386.36
Orthorhombic, P 2₁ 2₁ 2₁
a = 5.6355 (4) Å
b = 8.1597 (5) Å
c = 36.794 (2) Å
V = 1691.95 (19) Å³
Z = 4
Mo Kα radiation
μ = 0.11 mm⁻¹
T = 293 K
0.08 × 0.02 × 0.01 mm

Data collection

Bruker APEXII CCD area-detector diffractometer
Absorption correction: multi-scan (SADABS; Sheldrick, 2000 ) T_min = 0.764, T_max = 0.999
18174 measured reflections
3708 independent reflections
1466 reflections with I > 2σ(I)
R_int = 0.132

Refinement

R[F² > 2σ(F²)] = 0.074
wR(F²) = 0.242
S = 0.88
3708 reflections
263 parameters
H-atom parameters constrained
Δρ_max = 0.25 e Å⁻³
Δρ_min = −0.22 e Å⁻³

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
N3—H03⋯O4	0.86	1.99	2.617 (7)	129
C11—H11⋯O4ⁱ	0.93	2.47	3.251 (8)	142
C20—H20⋯N4	0.93	2.25	2.894 (8)	126
Symmetry code: (i) $[x+{\script{1\over 2}}, -y+{\script{3\over 2}}, -z]$ .

Data collection: APEX2 (Bruker, 2003 ); cell refinement: SAINT (Bruker, 2003); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: DIAMOND (Brandenburg, 2006 ); software used to prepare material for publication: WinGX publication routines (Farrugia, 2012 ).

Supporting information

Crystal structure: contains datablocks I, global. DOI: https://doi.org/10.1107/S1600536813009197/bt6891sup1.cif

Structure factors: contains datablock I. DOI: https://doi.org/10.1107/S1600536813009197/bt6891Isup2.hkl

Supporting information file. DOI: https://doi.org/10.1107/S1600536813009197/bt6891Isup3.cml

checkCIF report

Comment top

The title compound was synthesized as part of an investigation of the coordination properties of Schiff bases functioning as ligands. Metal complexes based on Schiff bases have been developed in biology and macromolecular chemistry in the last years (Kahwa et al., 1986).

The three dimensional arrangement of the molecules is held together by weak hydrogen bonds interactions between C—H and nitro-oxygen atoms.

Each unit is almost planar with a maximum deviation of 0.179 (6) A for O2, bond lengths varying in the ranges of [1.331 (9)–1.463 (8), 1.215 (7)–1.242 (6), 1.294 (7)–1.461 (8) and 1.389 (7) A for C—C, N—O, C—N and N—N respectively] and bond angles agreeing with those for the initial ligands. Molecules grow along the a-axis giving layers in the plane bc with an ABAB disposition, as well as each A and B layers are actually an alternating double layer. Two neighbor units of compound 1 create an angle of 68.92 (3)° between them along the c-axis.

The angle between the two nitro groups and the central benzene ring by 83.6 (5) and 2.6 (6)°, and the angle between these two nitro groups is 11.1 (7)°. Dihedral angle between the two aromatic parts of the molecule are 179.7 (6) and -171.7 (6)°, for C8—C7—N4—N3 and C7—N4—N3—C1 respectively.

Related literature top

For general background to hydrazone derivatives, see: Kahwa et al. (1986). For structural and coordination information for 2,4-dinitrophenylhydrazine and 9-anthraldehyde, see: Okabe et al. (1993) and Trotter (1959), respectively.

Experimental top

All reagents were obtained from commercial sources and used wirh no further purifications.

The compound was obtained when 1 g of (2,4-dinitrophenyl) hydrazine was dissolved in 5 mL of concentrated H₂SO₄.7.5 mL of water where added very slowly to the solution, after this were also added 25 mL of ethanol. In other flask, 4 mL of ethanol 0.05 g of anthracene-9-carbaldehyde where dissolved, and then, 1.80 mL of (2,4-dinitrophenyl)hydrazine was added to the solution. The two solutions were mixed and left to stand, at room temperature, for 24 h and then the solid compound was filtered., 049 g (52,7%)of the final product were obtained.

Structure description top

The three dimensional arrangement of the molecules is held together by weak hydrogen bonds interactions between C—H and nitro-oxygen atoms.

Computing details top

Data collection: APEX2 (Bruker, 2003); cell refinement: SAINT (Bruker, 2003); data reduction: SAINT (Bruker, 2003); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: DIAMOND (Brandenburg, 2006); software used to prepare material for publication: WinGX publication routines (Farrugia, 2012).

Figures top

	Fig. 1. : Asymmetric unit of the title compound, showing the atom-labelling scheme and displacement ellipsoids drawn at the 50% probability level.
	Fig. 2. : View of the crystal packing of the title compound, projected along c.
	Fig. 3. : A view showing part of the three-dimensional supramolecular network linked by weak hydrogen-bond interactions (yellow dotted lines).

1-[(E)-Anthracen-9-ylmethylidene]-2-(2,4-dinitrophenyl)hydrazine top

Crystal data top

C₂₁H₁₄N₄O₄	F(000) = 146
M_r = 386.36	D_x = 1.517 Mg m⁻³
Orthorhombic, P2₁2₁2₁	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: P 2ac 2ab	Cell parameters from 1164 reflections
a = 5.6355 (4) Å	θ = 3.0–18.8°
b = 8.1597 (5) Å	µ = 0.11 mm⁻¹
c = 36.794 (2) Å	T = 293 K
V = 1691.95 (19) Å³	Needle, colorless
Z = 4	0.08 × 0.02 × 0.01 mm

Data collection top

Bruker APEXII CCD area-detector diffractometer	3708 independent reflections
Radiation source: fine-focus sealed tube	1466 reflections with I > 2σ(I)
Graphite monochromator	R_int = 0.132
φ and ω scans	θ_max = 27.3°, θ_min = 3.3°
Absorption correction: multi-scan (SADABS; Sheldrick, 2000)	h = −7→7
T_min = 0.764, T_max = 0.999	k = −10→9
18174 measured reflections	l = −46→46

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)] = 0.074	H-atom parameters constrained
wR(F²) = 0.242	w = 1/[σ²(F_o²) + (0.1212P)²] where P = (F_o² + 2F_c²)/3
S = 0.88	(Δ/σ)_max < 0.001
3708 reflections	Δρ_max = 0.25 e Å⁻³
263 parameters	Δρ_min = −0.22 e Å⁻³
0 restraints	Extinction correction: SHELXL, Fc^*=kFc[1+0.001xFc²λ³/sin(2θ)]^-1/4
Primary atom site location: structure-invariant direct methods	Extinction coefficient: 0.036 (5)

Crystal data top

C₂₁H₁₄N₄O₄	V = 1691.95 (19) Å³
M_r = 386.36	Z = 4
Orthorhombic, P2₁2₁2₁	Mo Kα radiation
a = 5.6355 (4) Å	µ = 0.11 mm⁻¹
b = 8.1597 (5) Å	T = 293 K
c = 36.794 (2) Å	0.08 × 0.02 × 0.01 mm

Data collection top

Bruker APEXII CCD area-detector diffractometer	3708 independent reflections
Absorption correction: multi-scan (SADABS; Sheldrick, 2000)	1466 reflections with I > 2σ(I)
T_min = 0.764, T_max = 0.999	R_int = 0.132
18174 measured reflections

Refinement top

R[F² > 2σ(F²)] = 0.074	0 restraints
wR(F²) = 0.242	H-atom parameters constrained
S = 0.88	Δρ_max = 0.25 e Å⁻³
3708 reflections	Δρ_min = −0.22 e Å⁻³
263 parameters

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.

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

	x	y	z	U_iso*/U_eq
O1	0.2253 (10)	0.1891 (7)	0.26020 (13)	0.0951 (18)
O2	−0.0875 (10)	0.1412 (7)	0.22882 (14)	0.0932 (17)
O3	−0.1033 (8)	0.2666 (5)	0.10426 (11)	0.0669 (13)
O4	0.1605 (8)	0.4177 (5)	0.07843 (12)	0.0703 (13)
N1	0.1114 (12)	0.2008 (7)	0.23234 (16)	0.0725 (16)
N2	0.0789 (10)	0.3493 (6)	0.10576 (14)	0.0558 (14)
N3	0.5138 (9)	0.5396 (6)	0.11586 (14)	0.0559 (14)
H03	0.4470	0.5385	0.0948	0.067*
N4	0.7204 (9)	0.6275 (6)	0.12078 (13)	0.0561 (14)
C1	0.4148 (10)	0.4550 (7)	0.14367 (16)	0.0475 (14)
C2	0.2018 (10)	0.3647 (7)	0.13979 (15)	0.0481 (15)
C3	0.1020 (12)	0.2848 (7)	0.16947 (17)	0.0554 (16)
H3	−0.0398	0.2275	0.1671	0.066*
C4	0.2148 (11)	0.2921 (8)	0.20181 (16)	0.0536 (16)
C5	0.4246 (11)	0.3756 (8)	0.20701 (17)	0.0582 (17)
H5	0.4983	0.3771	0.2296	0.070*
C6	0.5215 (11)	0.4563 (8)	0.17795 (17)	0.0562 (16)
H6	0.6626	0.5137	0.1811	0.067*
C7	0.7784 (10)	0.7172 (7)	0.09321 (16)	0.0497 (15)
H7	0.6795	0.7136	0.0730	0.060*
C8	0.9857 (10)	0.8234 (7)	0.09117 (16)	0.0490 (15)
C9	1.0328 (10)	0.8946 (7)	0.05641 (16)	0.0482 (15)
C10	0.8823 (13)	0.8738 (8)	0.02552 (16)	0.0609 (17)
H10	0.7477	0.8083	0.0274	0.073*
C11	0.9330 (12)	0.9482 (8)	−0.00647 (18)	0.0667 (19)
H11	0.8285	0.9355	−0.0258	0.080*
C12	1.1380 (13)	1.0440 (8)	−0.0115 (2)	0.070 (2)
H12	1.1724	1.0905	−0.0339	0.084*
C13	1.2834 (13)	1.0664 (7)	0.01730 (19)	0.0652 (18)
H13	1.4182	1.1309	0.0145	0.078*
C14	1.2364 (12)	0.9944 (7)	0.05161 (17)	0.0519 (15)
C15	1.3859 (11)	1.0226 (7)	0.08107 (18)	0.0583 (17)
H15	1.5209	1.0862	0.0777	0.070*
C21	1.1340 (10)	0.8580 (7)	0.12098 (15)	0.0466 (14)
C16	1.3403 (10)	0.9587 (7)	0.11560 (17)	0.0525 (16)
C17	1.4973 (12)	0.9911 (8)	0.14472 (18)	0.0591 (17)
H17	1.6304	1.0560	0.1407	0.071*
C18	1.4578 (12)	0.9301 (8)	0.1779 (2)	0.0660 (19)
H18	1.5653	0.9491	0.1966	0.079*
C19	1.2511 (12)	0.8366 (8)	0.18424 (18)	0.0635 (18)
H19	1.2202	0.7970	0.2075	0.076*
C20	1.0978 (12)	0.8040 (8)	0.15704 (17)	0.0604 (17)
H20	0.9623	0.7433	0.1622	0.073*

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
O1	0.097 (4)	0.130 (5)	0.059 (3)	−0.006 (4)	−0.007 (3)	0.025 (3)
O2	0.080 (4)	0.121 (4)	0.079 (3)	−0.027 (4)	0.010 (3)	0.016 (3)
O3	0.056 (3)	0.074 (3)	0.070 (3)	−0.017 (3)	−0.005 (2)	0.000 (2)
O4	0.069 (3)	0.085 (3)	0.057 (3)	−0.020 (3)	0.000 (2)	0.010 (2)
N1	0.071 (4)	0.086 (4)	0.061 (4)	0.004 (4)	0.007 (4)	0.004 (3)
N2	0.054 (3)	0.057 (3)	0.057 (3)	0.005 (3)	−0.004 (3)	−0.002 (3)
N3	0.053 (3)	0.055 (3)	0.059 (3)	−0.004 (3)	0.002 (3)	−0.001 (3)
N4	0.045 (3)	0.059 (3)	0.065 (3)	−0.001 (3)	0.002 (3)	0.001 (3)
C1	0.043 (3)	0.050 (3)	0.050 (4)	0.000 (3)	0.000 (3)	0.001 (3)
C2	0.044 (4)	0.052 (4)	0.048 (3)	−0.003 (3)	−0.002 (3)	0.002 (3)
C3	0.047 (3)	0.054 (4)	0.066 (4)	−0.002 (3)	0.008 (3)	−0.008 (3)
C4	0.052 (4)	0.065 (4)	0.045 (4)	−0.002 (4)	0.003 (3)	0.004 (3)
C5	0.056 (4)	0.068 (4)	0.051 (4)	0.006 (4)	−0.005 (3)	−0.004 (3)
C6	0.050 (4)	0.058 (4)	0.061 (4)	−0.004 (3)	−0.005 (3)	−0.001 (3)
C7	0.049 (4)	0.051 (4)	0.049 (3)	−0.001 (3)	0.003 (3)	−0.002 (3)
C8	0.044 (3)	0.039 (3)	0.064 (4)	−0.002 (3)	0.006 (3)	−0.001 (3)
C9	0.045 (3)	0.042 (3)	0.059 (4)	0.006 (3)	0.001 (3)	−0.001 (3)
C10	0.063 (4)	0.063 (4)	0.056 (4)	0.001 (4)	−0.002 (4)	0.002 (3)
C11	0.064 (5)	0.076 (5)	0.060 (4)	0.006 (4)	−0.004 (4)	0.005 (4)
C12	0.084 (5)	0.062 (4)	0.065 (4)	0.003 (4)	0.014 (4)	0.011 (4)
C13	0.072 (4)	0.045 (4)	0.079 (5)	−0.007 (4)	0.014 (4)	0.007 (3)
C14	0.058 (4)	0.040 (3)	0.058 (4)	−0.002 (3)	0.002 (3)	−0.001 (3)
C15	0.053 (4)	0.046 (4)	0.076 (5)	0.000 (3)	0.013 (4)	−0.002 (3)
C21	0.044 (3)	0.040 (3)	0.055 (4)	0.001 (3)	0.002 (3)	−0.003 (3)
C16	0.043 (4)	0.045 (3)	0.069 (4)	0.009 (3)	0.000 (3)	−0.007 (3)
C17	0.046 (4)	0.060 (4)	0.072 (5)	−0.002 (3)	−0.004 (4)	−0.006 (4)
C18	0.057 (4)	0.070 (5)	0.071 (5)	0.007 (4)	−0.010 (4)	−0.006 (4)
C19	0.067 (5)	0.065 (4)	0.059 (4)	0.007 (4)	−0.001 (4)	0.006 (3)
C20	0.057 (4)	0.058 (4)	0.067 (4)	−0.006 (4)	0.000 (4)	−0.001 (3)

Geometric parameters (Å, º) top

O1—N1	1.214 (7)	C9—C14	1.418 (8)
O2—N1	1.229 (7)	C9—C10	1.428 (8)
O3—N2	1.230 (6)	C10—C11	1.355 (8)
O4—N2	1.238 (6)	C10—H10	0.9300
N1—C4	1.469 (8)	C11—C12	1.407 (9)
N2—C2	1.436 (7)	C11—H11	0.9300
N3—C1	1.355 (7)	C12—C13	1.351 (9)
N3—N4	1.379 (6)	C12—H12	0.9300
N3—H03	0.8600	C13—C14	1.418 (8)
N4—C7	1.293 (7)	C13—H13	0.9300
C1—C6	1.397 (8)	C14—C15	1.392 (8)
C1—C2	1.416 (8)	C15—C16	1.397 (8)
C2—C3	1.390 (8)	C15—H15	0.9300
C3—C4	1.350 (8)	C21—C20	1.413 (7)
C3—H3	0.9300	C21—C16	1.437 (8)
C4—C5	1.378 (8)	C16—C17	1.414 (8)
C5—C6	1.369 (8)	C17—C18	1.337 (9)
C5—H5	0.9300	C17—H17	0.9300
C6—H6	0.9300	C18—C19	1.412 (9)
C7—C8	1.456 (7)	C18—H18	0.9300
C7—H7	0.9300	C19—C20	1.348 (8)
C8—C21	1.408 (8)	C19—H19	0.9300
C8—C9	1.430 (8)	C20—H20	0.9300

O1—N1—O2	122.7 (6)	C11—C10—C9	120.8 (7)
O1—N1—C4	118.4 (6)	C11—C10—H10	119.6
O2—N1—C4	118.8 (6)	C9—C10—H10	119.6
O3—N2—O4	121.4 (5)	C10—C11—C12	122.4 (7)
O3—N2—C2	119.3 (5)	C10—C11—H11	118.8
O4—N2—C2	119.3 (5)	C12—C11—H11	118.8
C1—N3—N4	120.9 (5)	C13—C12—C11	118.1 (6)
C1—N3—H03	119.6	C13—C12—H12	121.0
N4—N3—H03	119.6	C11—C12—H12	121.0
C7—N4—N3	113.9 (5)	C12—C13—C14	121.9 (7)
N3—C1—C6	120.0 (6)	C12—C13—H13	119.0
N3—C1—C2	122.6 (6)	C14—C13—H13	119.0
C6—C1—C2	117.4 (5)	C15—C14—C13	120.8 (6)
C3—C2—C1	120.5 (5)	C15—C14—C9	119.2 (6)
C3—C2—N2	116.7 (5)	C13—C14—C9	120.0 (6)
C1—C2—N2	122.8 (5)	C14—C15—C16	122.4 (6)
C4—C3—C2	118.8 (6)	C14—C15—H15	118.8
C4—C3—H3	120.6	C16—C15—H15	118.8
C2—C3—H3	120.6	C8—C21—C20	125.7 (6)
C3—C4—C5	123.2 (6)	C8—C21—C16	119.2 (5)
C3—C4—N1	117.7 (6)	C20—C21—C16	115.1 (6)
C5—C4—N1	119.0 (6)	C15—C16—C17	120.3 (6)
C6—C5—C4	118.1 (6)	C15—C16—C21	119.2 (6)
C6—C5—H5	120.9	C17—C16—C21	120.6 (6)
C4—C5—H5	120.9	C18—C17—C16	121.2 (6)
C5—C6—C1	122.0 (6)	C18—C17—H17	119.4
C5—C6—H6	119.0	C16—C17—H17	119.4
C1—C6—H6	119.0	C17—C18—C19	119.3 (6)
N4—C7—C8	125.5 (6)	C17—C18—H18	120.4
N4—C7—H7	117.3	C19—C18—H18	120.4
C8—C7—H7	117.3	C20—C19—C18	120.8 (6)
C21—C8—C9	120.4 (5)	C20—C19—H19	119.6
C21—C8—C7	123.7 (5)	C18—C19—H19	119.6
C9—C8—C7	115.9 (5)	C19—C20—C21	122.9 (6)
C14—C9—C10	116.7 (5)	C19—C20—H20	118.6
C14—C9—C8	119.7 (5)	C21—C20—H20	118.6
C10—C9—C8	123.6 (6)

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
N3—H03···O4	0.86	1.99	2.617 (7)	129
C11—H11···O4ⁱ	0.93	2.47	3.251 (8)	142
C20—H20···N4	0.93	2.25	2.894 (8)	126

Symmetry code: (i) x+1/2, −y+3/2, −z.

Experimental details

Crystal data
Chemical formula	C₂₁H₁₄N₄O₄
M_r	386.36
Crystal system, space group	Orthorhombic, P2₁2₁2₁
Temperature (K)	293
a, b, c (Å)	5.6355 (4), 8.1597 (5), 36.794 (2)
V (Å³)	1691.95 (19)
Z	4
Radiation type	Mo Kα
µ (mm⁻¹)	0.11
Crystal size (mm)	0.08 × 0.02 × 0.01

Data collection
Diffractometer	Bruker APEXII CCD area-detector
Absorption correction	Multi-scan (SADABS; Sheldrick, 2000)
T_min, T_max	0.764, 0.999
No. of measured, independent and observed [I > 2σ(I)] reflections	18174, 3708, 1466
R_int	0.132
(sin θ/λ)_max (Å⁻¹)	0.646

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.074, 0.242, 0.88
No. of reflections	3708
No. of parameters	263
H-atom treatment	H-atom parameters constrained
Δρ_max, Δρ_min (e Å⁻³)	0.25, −0.22

Computer programs: APEX2 (Bruker, 2003), SAINT (Bruker, 2003), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), DIAMOND (Brandenburg, 2006), WinGX publication routines (Farrugia, 2012).

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
N3—H03···O4	0.86	1.99	2.617 (7)	129.4
C11—H11···O4ⁱ	0.93	2.47	3.251 (8)	142.2
C20—H20···N4	0.93	2.25	2.894 (8)	125.5

Symmetry code: (i) x+1/2, −y+3/2, −z.

Acknowledgements

This work was supported by the Fundo Europeu de Desenvolvimento Regional-QREN-Compete through projects SFRH/BD/61637/2009, PTDC/AAC-CLI/098308/2008, PTDC/AAC-CLI/118092/2010, PTDC/FIS/102284/2008 and PEst-C/FIS/UI0036/2011 – Fundação para a Ciência e Tecnologia (FCT).

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