Bromidotricarbon­yl[2-(pyridin-2-yl-κN)-5-p-tolyl-1,3,4-oxadiazole-κN 3]rhenium(I) dichloro­methane monosolvate

Lin-Fang Shi; Yan-wei Li; Zhen-jun Si; Ying Guan; Hua-ru Cao

doi:10.1107/S160053681004969X

. 2010 Dec 4;67(Pt 1):m9–m10. doi: 10.1107/S160053681004969X

Bromidotricarbonyl[2-(pyridin-2-yl-κN)-5-p-tolyl-1,3,4-oxadiazole-κN ³]rhenium(I) dichloromethane monosolvate

Lin-Fang Shi ^a,^*, Yan-wei Li ^b, Zhen-jun Si ^c, Ying Guan ^a, Hua-ru Cao ^a

PMCID: PMC3050244 PMID: 21522604

Abstract

In the title compound, [ReBr(C₁₄H₁₁N₃O)(CO)₃]·CH₂Cl₂, the coordination geometry of the Re^I atom is a distorted ReC₃N₂Br octahedron with the carbonyl C atoms in a fac arrangement. Within the 2-(pyridin-2-yl)-5-p-tolyl-1,3,4-oxadiazole ligand, the dihedral angles between the oxadiazole ring and the pyridine (py) and benzene (bz) rings are 1.7 (2) and 7.1 (2)°, respectively, and the dihedral angle between the py and bz rings is 5.5 (2)°. In the crystal, aromatic π–π stacking between the oxadiazole rings of adjacent molecules [centroid–centroid separation = 3.465 (3) Å] is seen.

Related literature

For backgroud to phosphoresence in Re(I) complexes, see: Ley et al. (1997 ▶); Zhang et al. (2009 ▶). For a related structure, see: Rajendran et al. (2000 ▶). For the synthesis of the ligand, see: Demko & Sharpless (2001 ▶); Tamoto et al. (1997 ▶).

Experimental

Crystal data

[ReBr(C₁₄H₁₁N₃O)(CO)₃]·CH₂Cl₂
M _r = 672.32
Monoclinic,
a = 12.590 (3) Å
b = 19.621 (4) Å
c = 17.660 (4) Å
β = 101.77 (3)°
V = 4270.8 (15) Å³
Z = 8
Mo Kα radiation
μ = 7.84 mm⁻¹
T = 293 K
0.25 × 0.22 × 0.11 mm

Data collection

Bruker SMART CCD diffractometer
Absorption correction: multi-scan (SADABS; Bruker, 2002) ▶ T _min = 0.149, T _max = 0.409
20653 measured reflections
4847 independent reflections
4254 reflections with I > 2σ(I)
R _int = 0.063

Refinement

R[F ² > 2σ(F ²)] = 0.040
wR(F ²) = 0.103
S = 1.05
4847 reflections
262 parameters
H-atom parameters constrained
Δρ_max = 2.07 e Å⁻³
Δρ_min = −2.88 e Å⁻³

Data collection: SMART (Bruker, 2002 ▶); cell refinement: SAINT (Bruker, 2002 ▶); 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: SHELXL97.

Supplementary Material

Crystal structure: contains datablocks global, I. DOI: 10.1107/S160053681004969X/hb5758sup1.cif

e-67-000m9-sup1.cif^{(18.3KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S160053681004969X/hb5758Isup2.hkl

e-67-000m9-Isup2.hkl^{(237.5KB, hkl)}

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

Table 1. Selected bond lengths (Å).

Re1—C1	1.887 (6)
Re1—C2	1.921 (5)
Re1—C3	1.890 (5)
Re1—N1	2.228 (4)
Re1—N2	2.169 (4)
Re1—Br1	2.6146 (11)

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Acknowledgments

This work was supported by Zhejiang A & F University Science Foundation (2009FR068).

supplementary crystallographic information

Comment

As part of our studies of possible phosphorescent materials containing Re(I) (Ley et al., 1997), we have synthesized the title Re(I) complex, (I), which contain the oxadiazole ligand of 2-(pyridin-2-yl)-5-p-tolyl-1,3,4-oxadiazole and characterized its structure by single-crystal X-ray diffraction analysis. Its luminescent property will be further studied in the coming research.

As shown in Scheme 1 and Figure 1, [Re(CO)₃(L)Br].CH₂Cl₂ is a six-coordinated complex. The coordination geometry at the Re atom is a distorted octahedron with the three carbonyl ligands arranged in a facial fashion. The distances of C(1), C(2), and C(3) to Re(1) are 1.887 (6), 1.921 (5), and 1.890 (5), respectively, and the Re—N bonds distances are 2.228 (4) and 2.169 (4). The bond angles in Table 1 clearly indicate that the CO ligands are linearly coordinated. The bond angles between adjacent CO carbon atoms are 87.8 (3), 89.1 (3) and 89.2 (3) degree, respectively, which is close to 90 degree, but the bond angle between the coordinated nitrogen atoms of ligand is 73.26 (16), which is much less than 90. All other bond distances and angles are comparable to those found for the related Re(I) complexes (Rajendran et al., 2000).

Figure 2 displays inter-molecular face-to-face stacking present in the molecular structure of [Re(CO)₃(L)Br].CH₂Cl₂: the 1,3,4-oxadiazole moiety in one molecule is almost parallel to the other one from another complex molecule (the dihedral angle between the two planes is 1.65 degree), and the approximate distance between the two closest atoms (N2—N3) is only 3.349. Thus the complex molecule achieved a bonded dual-molecule structure which is believed a rigid one and will prevent geometric relaxation effectively (Zhang et al., 2009). This kind of rigid structure is expected possessing excellent luminescent properties.

Experimental

The oxadiazole ligand was synthesized according to the literature method (Demko et al., 2001; Tamoto et al., 1997) with some minor modification.[Re(CO)₃(L)Br] was synthesized according to the following procedure: L1 (0.06 g, 0.210 mmol) and Re(CO)₅Br (0.08 g, 0.200 mmol) were refluxed in 15 ml of toluene for 6 h. After the mixture was cooled to RT, the solvent was removed in a water bath under reduced pressure. The resulting yellow solid was purified by silica gel column chromatography with acetic acid ethyl ester and dichloromethane (v/v = 10:1). Yellow blocks of (I) were grown from slow evaporation of a CH₂Cl₂ solution.