(2-Methyl-4-oxo-4H-pyran-3-olato-κ2 O 3,O 4)bis­(triphenyl­phosphane-κP)copper(I)–triphenyl­phosphane–methanol (1/1/1)

Fabian M A Muller; Theunis J Muller; Gideon Steyl

doi:10.1107/S1600536811011470

. 2011 Apr 13;67(Pt 5):m581–m582. doi: 10.1107/S1600536811011470

(2-Methyl-4-oxo-4H-pyran-3-olato-κ² O ³,O ⁴)bis(triphenylphosphane-κP)copper(I)–triphenylphosphane–methanol (1/1/1)

Fabian M A Muller ^a, Theunis J Muller ^a, Gideon Steyl ^a,^*

PMCID: PMC3089247 PMID: 21754306

Abstract

In the title compound, [Cu(C₆H₅O₃)(C₁₈H₁₅P)₂]·C₁₈H₁₅P·CH₃OH, the pyran-4-one ring is appromimately planar (r.m.s deviation = 0.0138 Å), with the Cu^I atom 0.451 (5) Å out of the plane. The Cu^I atom has a distorted tetrahedral coordination. The O—Cu—O angle is 80.07 (8)° and the P—Cu—P angle is 123.49 (3)°. The crystal packing is stablized by intramolecular C—H⋯O interactions and intermolecular C—H⋯O and O—H⋯O interactions.

Related literature

The title compound is structurally related to the flavonolato, nitrosophenylhydroxylaminato and tropolonato derivatives, see: Spier et al. (1990 ▶); Charalambous et al. (1984 ▶); Steyl (2009 ▶). For related diketonato complexes, see: Odoko et al. (2002 ▶, 2003 ▶). For general background to pyranone ligands, see: Hider et al. (1984a ▶,b ▶); Kontoghiorghes et al. (1990 ▶); Kontoghiorghes (1995 ▶); Hedlund & Öhman (1988 ▶); Creeth et al. (2000 ▶).

Experimental

Crystal data

[Cu(C₆H₅O₃)(C₁₈H₁₅P)₂]·C₁₈H₁₅P·CH₄O
M _r = 1007.49
Monoclinic,
a = 20.5253 (7) Å
b = 13.5716 (4) Å
c = 20.3129 (7) Å
β = 119.205 (1)°
V = 4939.1 (3) Å³
Z = 4
Mo Kα radiation
μ = 0.59 mm⁻¹
T = 150 K
0.19 × 0.19 × 0.06 mm

Data collection

Bruker X8 APEXII 4K diffractometer
Absorption correction: multi-scan (SADABS; Bruker, 2004 ▶) T _min = 0.894, T _max = 0.965
58551 measured reflections
10787 independent reflections
8326 reflections with I > 2σ(I)
R _int = 0.058

Refinement

R[F ² > 2σ(F ²)] = 0.049
wR(F ²) = 0.127
S = 1.06
10787 reflections
625 parameters
H-atom parameters constrained
Δρ_max = 1.51 e Å⁻³
Δρ_min = −0.86 e Å⁻³

Data collection: APEX2 (Bruker, 2005 ▶); cell refinement: SAINT-Plus (Bruker, 2004 ▶); 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, 2007 ▶); software used to prepare material for publication: WinGX (Farrugia, 1999 ▶).

Supplementary Material

Crystal structure: contains datablocks global, I. DOI: 10.1107/S1600536811011470/fi2105sup1.cif

e-67-0m581-sup1.cif^{(38KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536811011470/fi2105Isup2.hkl

e-67-0m581-Isup2.hkl^{(516.9KB, hkl)}

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

Table 1. Selected bond lengths (Å).

Cu1—O1	2.046 (2)
Cu1—O2	2.175 (2)
Cu1—P1	2.2014 (7)
Cu1—P2	2.2692 (8)

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

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
O4—H4A⋯O1	0.84	1.8	2.637 (3)	174
C2—H2⋯O2	0.95	2.46	3.370 (3)	162
C12—H12⋯O2	0.95	2.54	3.412 (4)	153
C22—H22⋯O4ⁱ	0.95	2.51	3.144 (4)	125
C32—H32⋯O1	0.95	2.6	3.495 (3)	158
C53—H53⋯O4	0.95	2.52	3.398 (5)	154

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Symmetry code: (i) Inline graphic .

Acknowledgments

The University of the Free State is gratefully acknowledged for financial support and Leo Kirsten for the data collection.

supplementary crystallographic information

Comment

Pyranone ligands have remarkable properties for clinical purposes (Odoko et al. 2003). These ligands are relevant to the control of metal levels in the body and have been tested for administration for the amelioration of anaemia (Hider et al. 1984a,b) and the removal of iron (Kontoghiorghes et al. 1990) and aluminium (Kontoghiorghes, 1995). 3-hydroxy-2-methyl-4H- pyran-4-one is a naturally occurring non-toxic compound typically added as a food flavour enhancer. It has the ability to be deprotonated readily (pK_a = 8.38; Hedlund & Öhman, 1988) and can act as an anionic chelating O,O'-bidentate ligand towards a number of biologically active metal ions (Odoko et al. 2002). The efficacy of the Cu^II and Sn^II complexes in oral-care formations (Creeth et al. 2000) has also been reported. Only three other examples of copper triphenylphosphine complexes are known to date, which containes a five-membered O,O'-bidentate chelating ring system, i.e., the flavonolato, nitrosophenylhydroxylaminato and tropolonato derivatives (Spier et al., 1990; Charalambous et al. 1984; Steyl, 2009). In this paper, the structure of (2-methyl-4-oxo-4H-pyran-3-olato- κ²O³,O⁴) Copper(I) complex is reported (Fig. 1). The pyran-4-one ring is essentially planar (r.m.s = 0.0138 fitted atoms C55, C56, C57, C58, C59 and O3). The Cu atom is situated 0.4508 (48) Å above the pyran-4-one ring plane. The Cu—O1 and Cu—O2 bond lengths are 2.046 (2) Å and 2.175 Å, respectively, this correlates well with literature (Steyl, 2009). The bidentate bite angle O1—Cu—O2 is 80.07 (8) ° which correlates with the observed literature values (Odoko et al. 2003). The Cu—P1 and Cu—P2 bond length is 2.2014 (7) and 2.2692 (8) Å, respectively, this is within normal range (Spier et al. 1990; Charalambous et al. 1984). The P1—Cu—P2 bond angle is 123.49 (3) °. O4–H4A···O1 hydrogen interactions between the solvent molecule and the complex and C53—H53···O1 hydrogen interaction between the free phosphie and complex stabilze the crystal packing. The crystal is further stabilized by inter- and intramolecular C—H···O hydrogen interactions (Table 2).

Experimental

A solution of [Cu(NO₃)(PPh₃)₂] (0.6502 g, 0.001 mol) in methanol (10 ml) was slowly added to a solution of 3-hydroxy-2-methyl-4H-pyran-4-one (0.1387 g, 0.0011 mol) in methanol (10 ml) and stirred for 30 minutes. Recrystallization from methanol gave X-Ray quality crystals. Yield 78%.