Dibromido(2,3,9,10-tetra­methyl-1,4,8,11-tetra­azacyclo­tetra­deca-1,3,8,10-tetra­ene)cobalt(III) bromide

El-Ghamry, H.; Issa, R.; El-Baradie, K.; Masaoka, S.; Sakai, K.

doi:10.1107/S160053680904166X

metal-organic compounds

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ISSN: 2056-9890

Volume 65| Part 11| November 2009| Pages m1378-m1379

https://doi.org/10.1107/S160053680904166X

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Dibromido(2,3,9,10-tetramethyl-1,4,8,11-tetraazacyclotetradeca-1,3,8,10-tetraene)cobalt(III) bromide

Hoda El-Ghamry,^a ^* Raafat Issa,^a Kamal El-Baradie,^a Shigeyuki Masaoka ^b and Ken Sakai ^b ‡

^aDepartment of Chemistry, Faculty of Science, Tanta University, Tanta, Egypt, and ^bDepartment of Chemistry, Faculty of Science, Kyushu University, Hakozaki 6-10-1, Higashi-ku, Fukuoka 812-8581, Japan
^*Correspondence e-mail: helghamrymo@yahoo.com

(Received 2 October 2009; accepted 12 October 2009; online 17 October 2009)

In the title compound, [CoBr₂(C₁₄H₂₄N₄)]·Br, the Co^III ion is located on an inversion centre and possesses a distorted octahedral coordination geometry in which four nitrogen donors of the ligand molecule are in the equatorial plane and two Br⁻ ions occupy both the axial sites to give a trans isomer. The Br^-counter- anion is also located on an inversion centre.

Related literature

For background to macrocyclic ligands and their metal complexes, see: Baird et al. (1993 ); Chandra & Verma (2008 ) and references therein; Chaudhary et al. (2002 ); Comba et al. (1986 ); Douglas (1978 ); Jones et al. (1979 ). For background to H₂ evolution catalysis of macrocyclic metal complexes, see: Du et al. (2008 ); Fihri, Artero, Pereira & Fontecave (2008 ); Fihri, Artero, Razavet et al. (2008 ); Hu et al. (2007 ); Yamauchi et al. (2009 ). For the synthesis, see: Jackels et al. (1972 ).

Experimental

Crystal data

[CoBr₂(C₁₄H₂₄N₄)]·Br
M_r = 547.03
Triclinic, $[P \overline 1]$
a = 7.3888 (10) Å
b = 7.5157 (10) Å
c = 8.1929 (11) Å
α = 84.647 (10)°
β = 84.760 (10)°
γ = 84.094 (10)°
V = 449.04 (10) Å³
Z = 1
Mo Kα radiation
μ = 7.63 mm⁻¹
T = 100 K
0.60 × 0.40 × 0.30 mm

Data collection

Bruker SMART APEXII CCD-detector diffractometer
Absorption correction: multi-scan (SADABS; Sheldrick, 1996 ) T_min = 0.045, T_max = 0.101
4629 measured reflections
1758 independent reflections
1739 reflections with I > 2σ(I)
R_int = 0.015

Refinement

R[F² > 2σ(F²)] = 0.016
wR(F²) = 0.040
S = 1.15
1758 reflections
105 parameters
H-atom parameters constrained
Δρ_max = 0.39 e Å⁻³
Δρ_min = −0.72 e Å⁻³

Data collection: APEX2 (Bruker, 2006 ); cell refinement: SAINT (Bruker, 2004 ); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: KENX (Sakai, 2004 ); software used to prepare material for publication: SHELXL97, TEXSAN (Molecular Structure Corporation, 2001 ), KENX and ORTEPII (Johnson, 1976 ).

Supporting information

Crystal structure: contains datablocks global, I. DOI: https://doi.org/10.1107/S160053680904166X/is2468sup1.cif

Structure factors: contains datablock I. DOI: https://doi.org/10.1107/S160053680904166X/is2468Isup2.hkl

checkCIF report

Comment top

Most of the known synthetic macrocyclic ligands and their metal complexes have been prepared and characterized during the last few decades. Most commonly they are quadridentates containing nitrogen donor atoms, although compounds containing oxygen and sulfur donors are also known (Douglas, 1978). Metal template synthesis of multidentate and macromonocyclic ligands have been established over the last three decades as offering high yield and selective routes to new ligands and their complexes (Comba et al., 1986). Transition metal macrocyclic complexes have received much attention as active part of metalloenzymes (Chaudhary et al., 2002) as biomimic model compounds (Jones et al., 1979) due to their resemblance with natural proteins like hemerythrin and enzymes. They also played an important role as catalysts in oxidation and epoxidation processes (Chandra et al., 2008). There are some recent reports about some macrocyclic Co^II and Co^III complexes which showed high activity towards H₂ evolution electrochemically (Hu et al., 2007) or photochemically (Fihri, Artero, Pereira & Fontecave, 2008; Fihri, Artero, Razavet et al., 2008; Du et al., 2008). The title compound has been observed to evolve H₂ electrocatalytically in acetonitrile (Hu et al., 2007). Unfortunately, it is found that this compound does not show any catalytic activity towards H₂ evolution in a well known photosystem consisting of tris (2,2^'-bipyridine)ruthenium(II) as a photosensitizer, methylviologen (N,N^'-dimethyl-4,4^'-bipyridinium) as an electron mediator, and ethylenediaminetetraacetic acid disodium salt as a sacrificial electron donor. Because of our on-going studies on the H₂-evolving activity of Pt^II based molecular catalysts (Yamauchi et al., 2009), attempts have been made to obtain the Pt^II complex of the present macrocyclic ligand. However the metal exchange from Co^III to Pt^II has been unsuccessful so far, presunably due to the extremely high stability of the Co^III complex, during the course of these studies we have succeeded in the x-ray crystal structure determination of the present compound.

The Co^III ion and the Br^- ion involved as a counter anion are respectively located at crystallographic inversion centers. Because of these requirements four nitrogen donors, two of them are independent, comprise a crystalloaphically planar geometry and the Co^III ion is also located exactly on the same plane. The vector defined by the Co—Br bond is slightly declined from the vector which is peependicular to the basal plane consisting of the four nitrogen donor atoms which can be recognized from the N—Co—Br angles; [N2—Co1—Br1=91.78 (4)° and N1—Co1—Br1=89.14 (4)°]. It is also observed that the Co—N, N═C and N—C bond distances of 1.9208 (13), 1.288 (2) and 1.472 (2) Å, respectively, are in accordance with the reported values for similar Co^III imine type macrocyclic complexes [2,9-dimethyl-3,10- diphenyl-1,4,8,11-tetraazacyclotetradeca-1,3,8,10-tetraene)cobalt(III); Co—N, N═C and N—C distances are 1.923 (13), 1.278 (3) and 1.478 (3) Å, respectively] (Baird et al., 1993). The N2, C4, C5ⁱ, C6ⁱ and N1ⁱ atoms form an envelope geometry in which the triangle defined by atoms C4, C5ⁱ and C6ⁱ is canted by 60.77 (11)° with respect to the least square plane defined by N1ⁱ, C6ⁱ, C4 and N2 atoms [symmetry code: (i) -x + 1, -y + 1, -z + 2]. No remarkable intercationic or cation-anion interactions are found in the crystal.

Related literature top

For background to macrocyclic ligands and their metal complexes, see: Baird et al. (1993); Chandra & Verma (2008) and references therein; Chaudhary et al. (2002); Comba et al. (1986); Douglas (1978); Jones et al. (1979). For background to H₂ evolution catalysis of macrocyclic metal complexes, see: Du et al. (2008); Fihri, Artero, Pereira & Fontecave (2008); Fihri, Artero, Razavet et al. (2008); Hu et al. (2007); Yamauchi et al. (2009). For the synthesis, see: Jackels et al. (1972).

Experimental top

The title compound was synthesized according to the method reported by Jackels et al. (1972). Elemental analysis calculated for C₁₄H₂₄N₄Br₃Co: C 30.74, H 4.42, N 10.42%. Found: C 30.40, H 4.50, N 10.04%. ESI-TOF MS (positive ion, methanol): m/z 466.9 [M⁺]. IR (ν, cm^-1): 3204(w), 2980(m), 2933(s), 2889(s), 2766(w), 2005(m), 1615(w), 1597(m), 1476(m), 1461(s), 1426(m), 1408(m), 1372(w), 1333(w), 1288(m), 1214(s), 1187(m), 1026(m), 938(s), 868(m), 831(w), 806(w), 777(s), 560(w), 444(s). Recrystallization of the crude product by a method reported in the same paper resulted in the formation of dark green crystals suitable for X-ray diffraction analysis.

Structure description top

For background to macrocyclic ligands and their metal complexes, see: Baird et al. (1993); Chandra & Verma (2008) and references therein; Chaudhary et al. (2002); Comba et al. (1986); Douglas (1978); Jones et al. (1979). For background to H₂ evolution catalysis of macrocyclic metal complexes, see: Du et al. (2008); Fihri, Artero, Pereira & Fontecave (2008); Fihri, Artero, Razavet et al. (2008); Hu et al. (2007); Yamauchi et al. (2009). For the synthesis, see: Jackels et al. (1972).

Computing details top

Data collection: APEX2 (Bruker, 2006); cell refinement: SAINT (Bruker, 2004); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: KENX (Sakai, 2004); software used to prepare material for publication: SHELXL97 (Sheldrick, 2008), TEXSAN (Molecular Structure Corporation, 2001), KENX (Sakai, 2004) and ORTEP (Johnson, 1976).

Figures top

	Fig. 1. The molecular structure of (I) showing the atom-labeling scheme. Displacement ellipsoids are drawn at the 50% probability level.
	Fig. 2. A stereoview for the crystal packing of (I).

Dibromido(2,3,9,10-tetramethyl-1,4,8,11-tetraazacyclotetradeca-1,3,8,10- tetraene)cobalt(III) bromide top

Crystal data top

[CoBr₂(C₁₄H₂₄N₄)]·Br	Z = 1
M_r = 547.03	F(000) = 268
Triclinic, P1	? # Insert any comments here.
Hall symbol: -P 1	D_x = 2.023 Mg m⁻³
a = 7.3888 (10) Å	Mo Kα radiation, λ = 0.71073 Å
b = 7.5157 (10) Å	Cell parameters from 4684 reflections
c = 8.1929 (11) Å	θ = 2.5–28.3°
α = 84.647 (10)°	µ = 7.63 mm⁻¹
β = 84.76 (1)°	T = 100 K
γ = 84.094 (10)°	Brocks, dark green
V = 449.04 (10) Å³	0.60 × 0.40 × 0.30 mm

Data collection top

Bruker SMART APEX CCD-detector diffractometer	1758 independent reflections
Radiation source: sealed tube	1739 reflections with I > 2σ(I)
Graphite monochromator	R_int = 0.015
φ and ω scans	θ_max = 26.0°, θ_min = 2.5°
Absorption correction: multi-scan (SADABS; Sheldrick, 1996)	h = −9→9
T_min = 0.045, T_max = 0.101	k = −9→9
4629 measured reflections	l = −10→10

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)] = 0.016	H-atom parameters constrained
wR(F²) = 0.040	w = 1/[σ²(F_o²) + (0.0205P)² + 0.2736P] where P = (F_o² + 2F_c²)/3
S = 1.15	(Δ/σ)_max = 0.001
1758 reflections	Δρ_max = 0.39 e Å⁻³
105 parameters	Δρ_min = −0.72 e Å⁻³
0 restraints	Extinction correction: SHELXL
Primary atom site location: structure-invariant direct methods	Extinction coefficient: 0.036 (4)

Crystal data top

[CoBr₂(C₁₄H₂₄N₄)]·Br	γ = 84.094 (10)°
M_r = 547.03	V = 449.04 (10) Å³
Triclinic, P1	Z = 1
a = 7.3888 (10) Å	Mo Kα radiation
b = 7.5157 (10) Å	µ = 7.63 mm⁻¹
c = 8.1929 (11) Å	T = 100 K
α = 84.647 (10)°	0.60 × 0.40 × 0.30 mm
β = 84.76 (1)°

Data collection top

Bruker SMART APEX CCD-detector diffractometer	1758 independent reflections
Absorption correction: multi-scan (SADABS; Sheldrick, 1996)	1739 reflections with I > 2σ(I)
T_min = 0.045, T_max = 0.101	R_int = 0.015
4629 measured reflections

Refinement top

R[F² > 2σ(F²)] = 0.016	0 restraints
wR(F²) = 0.040	H-atom parameters constrained
S = 1.15	Δρ_max = 0.39 e Å⁻³
1758 reflections	Δρ_min = −0.72 e Å⁻³
105 parameters

Special details top

Experimental. The first 50 frames were rescanned at the end of data collection to evaluate any possible decay phenomenon. Since it was judged to be negligible, no decay correction was applied to the data.

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.

Least-squares planes (x,y,z in crystal coordinates) and deviations from them (* indicates atom used to define plane)

4.5770 (0.0058) x + 4.5950 (0.0059) y - 3.7053 (0.0042) z = 0.8322 (0.0063)

* 0.0209 (0.0009) C4 * -0.0208 (0.0009) C6_$1 * -0.0182 (0.0008) N2 * 0.0181 (0.0008) N1_$1

Rms deviation of fitted atoms = 0.0195

- 2.0878 (0.0161) x + 6.6317 (0.0050) y - 1.8850 (0.0100) z = 2.7313 (0.0098)

Angle to previous plane (with approximate e.s.d.) = 60.77 (0.11)

* 0.0000 (0.0000) C4 * 0.0000 (0.0000) C5_$1 * 0.0000 (0.0000) C6_$1

Rms deviation of fitted atoms = 0.0000

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
Br1	0.32441 (2)	0.29517 (2)	1.169271 (18)	0.01131 (7)
Br2	0.0000	0.0000	0.5000	0.01880 (8)
Co1	0.5000	0.5000	1.0000	0.00682 (8)
N1	0.57154 (18)	0.31635 (18)	0.85246 (16)	0.0103 (3)
N2	0.30942 (18)	0.55749 (18)	0.85385 (16)	0.0097 (3)
C1	0.4642 (2)	0.3094 (2)	0.7383 (2)	0.0117 (3)
C2	0.3142 (2)	0.4563 (2)	0.7350 (2)	0.0109 (3)
C3	0.1898 (2)	0.4778 (3)	0.5990 (2)	0.0169 (4)
H3A	0.1135	0.3808	0.6109	0.025*
H3B	0.2612	0.4768	0.4951	0.025*
H3C	0.1150	0.5898	0.6038	0.025*
C4	0.1733 (2)	0.7132 (2)	0.8684 (2)	0.0143 (3)
H4A	0.0653	0.6924	0.8167	0.017*
H4B	0.2226	0.8187	0.8109	0.017*
C5	0.8791 (2)	0.2526 (2)	0.9535 (2)	0.0145 (3)
H5A	0.9114	0.3638	0.8933	0.017*
H5B	0.9864	0.1668	0.9480	0.017*
C6	0.7296 (2)	0.1820 (2)	0.8706 (2)	0.0148 (3)
H6A	0.7777	0.1473	0.7628	0.018*
H6B	0.6902	0.0758	0.9349	0.018*
C7	0.4802 (3)	0.1698 (2)	0.6181 (2)	0.0174 (4)
H7A	0.5370	0.2163	0.5150	0.026*
H7B	0.3608	0.1382	0.6021	0.026*
H7C	0.5531	0.0652	0.6598	0.026*

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
Br1	0.01353 (10)	0.01049 (10)	0.01015 (10)	−0.00325 (6)	−0.00175 (6)	0.00102 (6)
Br2	0.01990 (13)	0.01933 (14)	0.01523 (13)	0.00443 (10)	0.00017 (9)	0.00027 (10)
Co1	0.00848 (15)	0.00660 (14)	0.00573 (15)	−0.00006 (11)	−0.00254 (11)	−0.00114 (11)
N1	0.0123 (7)	0.0092 (6)	0.0097 (6)	−0.0010 (5)	−0.0021 (5)	−0.0005 (5)
N2	0.0107 (6)	0.0098 (6)	0.0085 (6)	−0.0012 (5)	−0.0019 (5)	0.0003 (5)
C1	0.0148 (8)	0.0110 (7)	0.0096 (7)	−0.0023 (6)	−0.0010 (6)	−0.0010 (6)
C2	0.0122 (8)	0.0120 (7)	0.0091 (7)	−0.0035 (6)	−0.0022 (6)	0.0002 (6)
C3	0.0185 (9)	0.0210 (9)	0.0125 (8)	0.0014 (7)	−0.0081 (7)	−0.0044 (7)
C4	0.0145 (8)	0.0140 (8)	0.0143 (8)	0.0047 (6)	−0.0057 (6)	−0.0020 (6)
C5	0.0133 (8)	0.0136 (8)	0.0162 (8)	0.0036 (6)	−0.0031 (6)	−0.0020 (7)
C6	0.0168 (8)	0.0120 (8)	0.0162 (8)	0.0038 (6)	−0.0046 (7)	−0.0063 (6)
C7	0.0232 (9)	0.0159 (8)	0.0147 (8)	0.0005 (7)	−0.0058 (7)	−0.0077 (7)

Geometric parameters (Å, º) top

Br1—Co1	2.3792 (2)	C3—H3C	0.9600
Co1—N2	1.9208 (13)	C4—H4A	0.9700
Co1—N1	1.9210 (13)	C4—H4B	0.9700
N1—C1	1.288 (2)	C5—C6	1.513 (2)
N1—C6	1.472 (2)	C5—H5A	0.9700
N2—C2	1.286 (2)	C5—H5B	0.9700
N2—C4	1.469 (2)	C6—H6A	0.9700
C1—C2	1.482 (2)	C6—H6B	0.9700
C1—C7	1.494 (2)	C7—H7A	0.9600
C2—C3	1.495 (2)	C7—H7B	0.9600
C3—H3A	0.9600	C7—H7C	0.9600
C3—H3B	0.9600

N2ⁱ—Co1—N2	180.000 (1)	C2—C3—H3C	109.5
N2—Co1—N1ⁱ	98.31 (6)	H3A—C3—H3C	109.5
N2ⁱ—Co1—N1	98.31 (6)	H3B—C3—H3C	109.5
N2—Co1—N1	81.69 (6)	N2—C4—H4A	109.3
N1ⁱ—Co1—N1	180.0	C5ⁱ—C4—H4A	109.3
N2—Co1—Br1ⁱ	88.22 (4)	N2—C4—H4B	109.3
N1—Co1—Br1ⁱ	90.86 (4)	C5ⁱ—C4—H4B	109.3
N2ⁱ—Co1—Br1	88.22 (4)	H4A—C4—H4B	108.0
N2—Co1—Br1	91.78 (4)	C6—C5—H5A	108.8
N1ⁱ—Co1—Br1	90.86 (4)	C4ⁱ—C5—H5A	108.8
N1—Co1—Br1	89.14 (4)	C6—C5—H5B	108.8
C1—N1—C6	120.39 (14)	C4ⁱ—C5—H5B	108.8
C1—N1—Co1	115.40 (11)	H5A—C5—H5B	107.7
C6—N1—Co1	124.08 (10)	N1—C6—C5	112.00 (13)
C2—N2—C4	121.39 (14)	N1—C6—H6A	109.2
C2—N2—Co1	115.56 (11)	C5—C6—H6A	109.2
C4—N2—Co1	122.93 (11)	N1—C6—H6B	109.2
N1—C1—C2	113.55 (14)	C5—C6—H6B	109.2
N1—C1—C7	125.76 (15)	H6A—C6—H6B	107.9
C2—C1—C7	120.68 (14)	C1—C7—H7A	109.5
N2—C2—C1	113.57 (14)	C1—C7—H7B	109.5
N2—C2—C3	126.51 (15)	H7A—C7—H7B	109.5
C1—C2—C3	119.89 (14)	C1—C7—H7C	109.5
C2—C3—H3A	109.5	H7A—C7—H7C	109.5
C2—C3—H3B	109.5	H7B—C7—H7C	109.5
H3A—C3—H3B	109.5

C6—N1—C1—C2	−178.89 (14)	C7—C1—C2—N2	174.67 (15)
Co1—N1—C1—C2	5.11 (18)	N1—C1—C2—C3	173.64 (15)
C6—N1—C1—C7	1.7 (3)	C7—C1—C2—C3	−6.9 (2)
Co1—N1—C1—C7	−174.28 (13)	C2—N2—C4—C5ⁱ	148.20 (15)
C4—N2—C2—C1	178.26 (14)	Co1—N2—C4—C5ⁱ	−35.93 (19)
Co1—N2—C2—C1	2.11 (18)	C1—N1—C6—C5	154.97 (15)
C4—N2—C2—C3	0.0 (3)	Co1—N1—C6—C5	−29.39 (19)
Co1—N2—C2—C3	−176.16 (14)	C4ⁱ—C5—C6—N1	66.89 (18)
N1—C1—C2—N2	−4.8 (2)

Symmetry code: (i) −x+1, −y+1, −z+2.

Experimental details

Crystal data
Chemical formula	[CoBr₂(C₁₄H₂₄N₄)]·Br
M_r	547.03
Crystal system, space group	Triclinic, P1
Temperature (K)	100
a, b, c (Å)	7.3888 (10), 7.5157 (10), 8.1929 (11)
α, β, γ (°)	84.647 (10), 84.76 (1), 84.094 (10)
V (Å³)	449.04 (10)
Z	1
Radiation type	Mo Kα
µ (mm⁻¹)	7.63
Crystal size (mm)	0.60 × 0.40 × 0.30

Data collection
Diffractometer	Bruker SMART APEX CCD-detector diffractometer
Absorption correction	Multi-scan (SADABS; Sheldrick, 1996)
T_min, T_max	0.045, 0.101
No. of measured, independent and observed [I > 2σ(I)] reflections	4629, 1758, 1739
R_int	0.015
(sin θ/λ)_max (Å⁻¹)	0.617

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.016, 0.040, 1.15
No. of reflections	1758
No. of parameters	105
H-atom treatment	H-atom parameters constrained
Δρ_max, Δρ_min (e Å⁻³)	0.39, −0.72

Computer programs: APEX2 (Bruker, 2006), SAINT (Bruker, 2004), SAINT, SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), TEXSAN (Molecular Structure Corporation, 2001), KENX (Sakai, 2004) and ORTEP (Johnson, 1976).

Footnotes

‡Additional correspondence author, e-mail: ksakai@chem.kyushu-univ.jp.

Acknowledgements

This work was supported in part by a Grant-in-Aid for Scientific Research (A) (No. 17205008), a Grant-in-Aid for Specially Promoted Research (No. 18002016) and a Grant-in-Aid for the Global COE Program (`Science for Future Molecular Systems') from the Ministry of Education, Culture, Sports, Science, and Technology of Japan. HE acknowledges the Egyptian Channel System for financial support to promote the joint research project between Tanta and Kyushu Universities.

References

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