Bis(1,10-phenanthroline-5,6-dione-κ2 N,N′)silver(I) tetra­fluoridoborate

Jonathan Onuegbu; Ray J Butcher; Charles Hosten; Uche Charles Udeochu; Oladapo Bakare

doi:10.1107/S160053680903222X

. 2009 Aug 22;65(Pt 9):m1119–m1120. doi: 10.1107/S160053680903222X

Bis(1,10-phenanthroline-5,6-dione-κ² N,N′)silver(I) tetrafluoridoborate

Jonathan Onuegbu ^a, Ray J Butcher ^a,^*, Charles Hosten ^a, Uche Charles Udeochu ^a, Oladapo Bakare ^a

PMCID: PMC2969900 PMID: 21577462

Abstract

In the structure of the title compound, [Ag(C₁₂H₆N₂O₂)₂]BF₄ or [AgL ₂]BF₄ (L = phendione), the Ag and B atoms are located on twofold rotation axes. The dihedral angle between the two phendione ligands is 36.7 (2)°. The coordination about the Ag^I center is distorted tetrahedral (τ₄ = 0.546). The crystal structure is consolidated by weak C—H⋯O(phendione) and C—H⋯F(BF₄ ⁻) interactions. The BF₄ ⁻ counter-anion is strongly disordered and was modelled with two sets of idealized F atoms.

Related literature

For the different coordination properties of phendione, see: Calderazzo et al. (1999 ▶, 2002 ▶); Calucci et al. (2006 ▶); Galet et al. (2005 ▶); Lei et al. (1996 ▶); Okamura et al. (2006 ▶). For examples with phendione ligands where N and O donors are used simultaneously, see: Fox et al. (1991 ▶); Shavaleev et al. (2003a ▶,b ▶); Ruiz et al. (1999 ▶); Paw & Eisenberg (1997 ▶). Similar structures containing Ag have also been reported by Onuegbu et al. (2007 ▶). For background to phendione chemistry, see: Udeochu et al. (2007 ▶); Onuegbu et al. (2007 ▶). For reference structural data, see: Allen (2002 ▶); Leschke et al. (2002 ▶); Paramonov et al. (2003 ▶); Pallenberg et al. (1997 ▶); Titze et al. (1997 ▶). Details of the τ₄ parameter were given by Yang et al. (2007 ▶).

Experimental

Crystal data

[Ag(C₁₂H₆N₂O₂)₂]BF₄
M _r = 615.06
Monoclinic,
a = 13.2249 (6) Å
b = 12.0115 (17) Å
c = 14.4338 (7) Å
β = 108.481 (5)°
V = 2174.6 (3) Å³
Z = 4
Mo Kα radiation
μ = 1.01 mm⁻¹
T = 200 K
0.44 × 0.37 × 0.28 mm

Data collection

Oxford Diffraction Gemini R diffractometer
Absorption correction: multi-scan (CrysAlis RED; Oxford Diffraction, 2007 ▶) T _min = 0.856, T _max = 1.000 (expected range = 0.646–0.755)
11815 measured reflections
3647 independent reflections
2306 reflections with I > 2σ(I)
R _int = 0.024

Refinement

R[F ² > 2σ(F ²)] = 0.047
wR(F ²) = 0.134
S = 0.98
3647 reflections
204 parameters
32 restraints
H-atom parameters constrained
Δρ_max = 1.81 e Å⁻³
Δρ_min = −1.39 e Å⁻³

Data collection: CrysAlis CCD (Oxford Diffraction, 2007 ▶); cell refinement: CrysAlis RED (Oxford Diffraction, 2007 ▶); data reduction: CrysAlis RED; 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: SHELXTL.

Supplementary Material

Crystal structure: contains datablocks global, I. DOI: 10.1107/S160053680903222X/wm2249sup1.cif

e-65-m1119-sup1.cif^{(19.4KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S160053680903222X/wm2249Isup2.hkl

e-65-m1119-Isup2.hkl^{(178.9KB, hkl)}

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

Table 1. Selected bond lengths (Å).

Ag—N1	2.356 (2)
Ag—N2	2.357 (2)

Open in a new tab

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

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
C3—H3A⋯O1ⁱ	0.95	2.51	3.347 (4)	147
C1—H1A⋯F1Aⁱⁱ	0.95	2.35	3.083 (6)	133
C2—H2A⋯F1B	0.95	2.17	2.803 (8)	123
C10—H10A⋯F2Aⁱⁱⁱ	0.95	2.24	2.859 (5)	122
C10—H10A⋯F2B^iv	0.95	2.28	3.065 (4)	140

Open in a new tab

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

Acknowledgments

RJB acknowledges the NSF–MRI program (grant No. CHE-0619278) for funds to purchase the X-ray diffractometer.

supplementary crystallographic information

Comment

Phendione (1,10-phenanthroline-5,6-dione) is an excellent ligand that incorporates two functional groups with different coordination properties (Calderazzo et al., 1999, 2002; Calucci et al., 2006; Galet et al., 2005; Lei et al., 1996; Okamura et al., 2006). This well known ligand possesses both the α-diimine and orthoquinone moieties. While phendione usually binds to metals through its imine N atoms, in some cases both the N and O donors are used simultaneously (Fox et al., 1991; Shavaleev et al., 2003a, b; Ruiz et al., 1999; Paw & Eisenberg, 1997). The crystal structures of two complexes of copper and phendione have been determined (Galet et al., 2005;). Similar structures containing Ag have also been reported (Onuegbu et al., 2007). In this paper, as part of our study of phendione chemistry (Udeochu et al., 2007; Onuegbu et al., 2007), we report the synthesis and characterization of the title compound, [AgL₂]⁺(BF₄)^-, (I).

The structure of (I), shown in Figure 1, is made up of an [Ag(L)₂]⁺ cation and a tetrafluoridoborate anion. The silver atom is coordinated to the two nitrogen atoms of both phendione ligands. Both the Ag atom of the cation and the B atom of the anion lie on a crystallographic twofold rotation axes. The C═O bond lengths in the phendione ligands (1.210 (4) and 1.206 (3) Å) are comparable to those values found in other such complexes (Allen, 2002; Onuegbu et al., 2007). The Ag—N bond lengths (2.356 (2) and 2.357 (2) Å) are similar to those found in related phenanthroline derivatives of silver (Leschke et al., 2002; Paramonov et al., 2003; Pallenberg et al., 1997; Titze et al., 1997).

In (I), the silver cation is in a distorted tetrahedral environment. This is best illustrated by the dihedral angle between the planes of the coordinated ligands which in this case the angle is 36.7 (2)°. This compares with values of 36.8 (2)° found in the analogous perchlorate analog and the values of 32.4° and 70.5° found for other structurally characterized Ag complexes containing the bis(1,10-phenanthroline) core. Another recent parameter for 4-coordinate complexes (τ₄, Yang et al., 2007) has been developed to place a structure on the continuum between square planar (0) and tetrahedral (1). For the present structure this value is 0.546.

Copper forms a similar complex with phendione. However, in this case the twofold axis passes between the phendione ligands with a dihedral angle of 44.5° between them.

In the structure of (I), there are weak C—H···O(phendione) and C—H···F(BF₄^-) interactions (Fig. 2).

Experimental

A flask containing 1,10-phenanthroline hydrate (1.00 g, 5.04 mmol) and potassium bromide (5.95 g, 50.0 mmol) was placed in an ice bath. Concentrated sulfuric acid (20 cm³) was added in small portions, followed by drop-wise addition of concentrated nitric acid (10 cm³). The resulting solution was heated for 2 h at 253–257 K and cooled to room temperature. The solution was then poured into 400 cm³ of water and neutralized with sodium bicarbonate, after which the phendione was extracted with dichloromethane, and recrystallized using a methanol-water mixture.

The title compound was synthesized in an atmosphere saturated with N₂. To a solution of tetrakis(acetonitrile)silver(I)tetrafluoridoborate (0.0843 g) in 10 ml of CH₃CN, was added drop-wise a solution (10 ml) of CH₃CN containing 0.0492 g of phendione. The final yellowish solution was filtered and allowed to slowly evaporate yielding reddish brown crystals of the title compound suitable for X-ray studies.