(μ1-Methano­lato-κ1 O)-μ1-methoxo-κ1 O-(μ2-2-amino-1-methyl-5H-imidazol-4-one-κ2 N:N′)-hexa­carbonyl­dirhenium(I)

M Schutte; H G Visser; A Roodt

doi:10.1107/S1600536812041700

. 2012 Oct 13;68(Pt 11):m1359–m1360. doi: 10.1107/S1600536812041700

(μ₁-Methanolato-κ¹ O)-μ₁-methoxo-κ¹ O-(μ₂-2-amino-1-methyl-5H-imidazol-4-one-κ² N:N′)-hexacarbonyldirhenium(I)

M Schutte ^a,^*, H G Visser ^a, A Roodt ^a

PMCID: PMC3515115 PMID: 23284342

Abstract

In the title compound, [Re₂(CH₃O)₂(CO)₆(C₄H₆N₃O)], the two Re^I atoms are linked by a methoxo and methanolato bridge, as well as by a creatinine ligand that coordinates in a bidentate fashion. Three fac-carbonyl ligands occupy the rest of the slightly distorted octahedral geometry around each Re^I atom. The bridging methanolato and methoxo ligands are bent out of the Re₂O₂ plane by 49.2 (4) and 47.8 (3)° respectively. This is normally associated with a methanolato-bridging-type coordination rather that the more planar methoxo-type bridging. Furthermore, the creatinine bridging molecule is very slightly distorted from the Re₂N₂C plane, indicating that the pyrazolo N atom bonded to the Rh^I atom is not protonated. Charge balance can thus only be attained if one assumes a positional disorder for the methanolato/methoxo H atom. All attempts to locate disordered protons around these O atoms were unsuccessful. Four hydrogen bonds, one N—H⋯O and three C—H⋯O, are observed in the structure. The molecules pack in a head-to-head and tail-to-tail fashion when viewed along the c axis, in alternating columns.

Related literature

For the synthesis of the starting material, see: Alberto et al. (1996 ▶). For similar Re^I methoxy-bridged structures, see: Franklin et al. (2008 ▶); Klausmeyer & Beckles (2006 ▶). For structures of creatinine, see: Bell et al. (1995 ▶); du Pré & Mendel (1955 ▶). For structures with creatinine as a monodentate ligand, see: Canty et al. (1979 ▶); Mitewa et al. (2002 ▶); Matos Beja et al. (1991 ▶); Panfil et al. (1995 ▶). For a tetranuclear Re^I complex, see: Schutte et al. (2012a ▶). For similar Re^I structures, see: Schutte et al. (2011 ▶, 2012b ▶,c ▶).

Experimental

Crystal data

[Re₂(CH₃O)₂(CO)₆(C₄H₆N₃O)]
M _r = 714.67
Orthorhombic,
a = 24.066 (2) Å
b = 10.0715 (8) Å
c = 14.5969 (11) Å
V = 3538.1 (5) Å³
Z = 8
Mo Kα radiation
μ = 13.73 mm⁻¹
T = 100 K
0.25 × 0.15 × 0.10 mm

Data collection

Bruker APEXII CCD diffractometer
Absorption correction: multi-scan (SADABS; Bruker, 2008 ▶) T _min = 0.174, T _max = 0.371
46753 measured reflections
4276 independent reflections
3920 reflections with I > 2σ(I)
R _int = 0.050

Refinement

R[F ² > 2σ(F ²)] = 0.030
wR(F ²) = 0.078
S = 1.16
4269 reflections
236 parameters
H atoms treated by a mixture of independent and constrained refinement
Δρ_max = 2.32 e Å⁻³
Δρ_min = −2.30 e Å⁻³

Data collection: APEX2 (Bruker, 2008 ▶); cell refinement: SAINT-Plus (Bruker, 2008 ▶); data reduction: SAINT-Plus; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: DIAMOND (Brandenburg & Putz, 2005 ▶); software used to prepare material for publication: WinGX (Farrugia, 1999 ▶).

Supplementary Material

Click here for additional data file.^{(23.2KB, cif)}

Crystal structure: contains datablock(s) global, I. DOI: 10.1107/S1600536812041700/tk5155sup1.cif

e-68-m1359-sup1.cif^{(23.2KB, cif)}

Click here for additional data file.^{(205KB, hkl)}

Structure factors: contains datablock(s) I. DOI: 10.1107/S1600536812041700/tk5155Isup2.hkl

e-68-m1359-Isup2.hkl^{(205KB, hkl)}

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

Table 1. Selected bond lengths (Å).

Re1—C11	1.886 (6)
Re1—C13	1.908 (7)
Re1—C12	1.918 (8)
Re1—O2	2.149 (4)
Re1—N3	2.150 (5)
Re1—O1	2.153 (4)
Re2—C21	1.849 (5)
Re2—C22	1.935 (6)
Re2—C23	1.949 (6)
Re2—O2	2.065 (4)
Re2—O1	2.073 (4)
Re2—N1	2.136 (5)

Open in a new tab

Table 2. Hydrogen-bond geometry (Å, °).

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
N3—H3⋯O31ⁱ	0.92 (8)	2.17 (8)	3.061 (6)	162 (7)
C2—H2B⋯O13ⁱⁱ	0.96	2.54	3.453 (9)	159
C2—H2C⋯O23ⁱⁱ	0.96	2.61	3.504 (9)	154
C34—H34A⋯O31ⁱ	0.96	2.44	3.332 (7)	155

Open in a new tab

Symmetry codes: (i) Inline graphic ; (ii) .

Acknowledgments

Leo Kirsten is thanked for the data collection. The University of the Free State, the Department of Chemistry, the NRF and Sasol Ltd are gratefully acknowledged for funding.

supplementary crystallographic information

Comment

C₁₂H₁₂N₃O₉Re₂ crystallized in the orthorhombic space group Pbcn with one unit in the asymmetric unit. The rhenium centres are linked with two methoxy bridges and a creatinine ligand (in a N,N'-bidentate fashion). Three facial tricarbonyl ligands occupy the other three positions on the distorted octahedron, Fig. 1 and Table 1. The Re—O—Re (104.01 (18)° and 104.4 (2)°) and O—Re—O (73.71 (16)° and 77.16 (17)°) bond angles compare well to the structure by Klausmeyer & Beckles (2006) that reported 103.66 (1)° and 103.33 (1)° (Re—O—Re) and 76.66 (1)° and 76.21 (1)° (O—Re—O), and to the structure by Franklin et al. (2008) that reported 108.24 (1)° and 108.24 (2)° (Re—O—Re) and 71.76 (12)° (O—Re—O) respectively. Creatinine is coordinated to various metal centres in a monodentate fashion (Canty et al. 1979, Mitewa et al. 2002, Matos Beja et al. 1991, Panfil et al. 1995) but no structure reports are found where creatinine is coordinated to a metal centre in a bidentate fashion. All bond distances and angles of creatinine in this structure compare well with that of the reported structures of the free ligand with the N—C—N angle the only exception with 121° (Bell et al., 1995) and 120° (du Pré & Mendel, 1955) reported for the free ligand and 123.7 (5)° for the coordinated ligand, respectively. The O—Re—O (73.71 (16)° and 77.16 (17)°) and Re—O—Re (104.01 (18)° and 104.4 (2)°) bond angles compare well to the tetranuclear rhenium(I) cubane-like molecule reported by Schutte et al. (2012a) with O—Re—O angles that vary between 73.5 (2)° and 75.0 (7)° and Re—O—Re angles that vary between 102.6 (3)° and 104.7 (2)°. This ligand, creatinine, forms part of an ongoing study where different N,N' bidentate and N,N',N'' tridentate ligands are synthesized and coordinated to the rhenium(I) metal centre (Schutte et al., 2011, 2012b, 2012c). Four intermolecular hydrogen bonds are observed in the structure, Table 2, i.e. one N—H···O and three C—H···O. When viewed along the c axis, the molecules pack in column-like structures in an alternating head-to-head and tail-to-tail fashion (Fig. 2).

Experimental

[NEt₄]₂[Re(CO)₃Br₃] (500 mg, 0.650 mmol), as prepared by Alberto et al. (1996), was dissolved in 10 ml of water at pH 2. The pH was increased to pH 6 and after a slight colour change, creatinine (37 mg, 0.325 mmol) was added to the mixture and stirred for 6 h at room temperature. The yellow cuboidal crystals were obtained from the filtrate of the solution.