Bis{μ-[(di­phenyl­phosphor­yl)meth­yl](phen­yl)bis­(1H-pyrazol-1-yl)boranuido}dilithium

Manuela Müller; Hans-Wolfram Lerner; Michael Bolte

doi:10.1107/S1600536814011945

. 2014 May 31;70(Pt 6):m237. doi: 10.1107/S1600536814011945

Bis{μ-[(diphenylphosphoryl)methyl](phenyl)bis(1H-pyrazol-1-yl)boranuido}dilithium

Manuela Müller ^a, Hans-Wolfram Lerner ^a, Michael Bolte ^a,^*

PMCID: PMC4051015 PMID: 24940216

Abstract

The title compound, [Li₂(C₂₅H₂₃BN₄OP)₂], features a centrosymmetric dimeric complex. The four-memberered Li₂O₂ ring is exactly planar due to symmetry. The Li atom is four-coordinated by two O atoms and by two N atoms of two different pyrazole rings. The dihedral angle between two pyrazole rings bonded to the same B atom is 45.66 (9)°. The B—N—N—Li—N—N metalla ring adopts a boat conformation. The crystal packing is stabilized by van der Waals interactions only.

Related literature

For background to scorpionates, see: Trofimenko (1993 ▶, 1999 ▶); Bieller et al. (2006 ▶). For related structures, see: Müller et al. (2014a ▶,b ▶).

Experimental

Crystal data

[Li₂(C₂₅H₂₃BN₄OP)₂]
M _r = 888.39
Monoclinic,
a = 10.0585 (6) Å
b = 16.2371 (8) Å
c = 14.4301 (8) Å
β = 98.854 (5)°
V = 2328.7 (2) Å³
Z = 2
Mo Kα radiation
μ = 0.14 mm⁻¹
T = 173 K
0.32 × 0.28 × 0.27 mm

Data collection

Stoe IPDS II two-circle diffractometer
Absorption correction: multi-scan (MULABS; Spek, 2009 ▶; Blessing, 1995 ▶) T _min = 0.956, T _max = 0.962
36952 measured reflections
4362 independent reflections
3630 reflections with I > 2σ(I)
R _int = 0.062

Refinement

R[F ² > 2σ(F ²)] = 0.041
wR(F ²) = 0.101
S = 1.02
4362 reflections
298 parameters
H-atom parameters constrained
Δρ_max = 0.36 e Å⁻³
Δρ_min = −0.29 e Å⁻³

Data collection: X-AREA (Stoe & Cie, 2001 ▶); cell refinement: X-AREA; data reduction: X-AREA; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: XP in SHELXTL (Sheldrick, 2008 ▶); software used to prepare material for publication: SHELXL97 and publCIF (Westrip, 2010 ▶).

Supplementary Material

Crystal structure: contains datablock(s) I, global. DOI: 10.1107/S1600536814011945/sj5403sup1.cif

e-70-0m237-sup1.cif^{(34.3KB, cif)}

Structure factors: contains datablock(s) I. DOI: 10.1107/S1600536814011945/sj5403Isup2.hkl

e-70-0m237-Isup2.hkl^{(213.8KB, hkl)}

CCDC reference: 883935

Additional supporting information: crystallographic information; 3D view; checkCIF report

supplementary crystallographic information

1. Comment

One way to alter the donor/acceptor properties of scorpionate ligands over a wider range is to replace the pyrazolyl rings by phosphorus-containing groups (Trofimenko, 1993; Trofimenko, 1999; Bieller et al., 2006). Similar to parent scorpionates these ligands provide a monoanionic, tridentate, face-capping coordination mode, but they differ from parent scorpionates with regard to the softness of their donor sets. Recently we have investigated the syntheses of the hybrid scorpionates Li(tmeda)[PhBpz₂(CH₂PPh₂)] (I) and Li(tmeda)₂[PhB(CH₂PPh₂)₃] (II) (Müller et al., 2014a). The lithium scorpionates I and II, however, are air-sensitive. The heteroscorpionates I and II react with oxygen from the air to give the corresponding oxo-heteroscorpionates as shown in the scheme (Fig. 1). After storing solutions of I and II under ambient conditions (in the presence of oxygen from the air) crystals of the oxo-heteroscorpionates III and IV could be isolated (Müller et al., 2014b).

The title compound features a centrosymmetric dimeric complex (Fig. 2). The four-memberered Li₂O₂ ring is exactly planar due to the symmetry. Each Li centre is four-coordinated by two oxygen atoms and two nitrogen atoms of two different pyrazol rings. The dihedral angle between two pyrazol rings bonded to the same boron atom is 45.66 (9)°. The B—N—N—Li—N—N ring adopts a boat conformation. The crystal packing is stabilized only by van der Waals interactions (Fig. 3).

2. Experimental

Single crystals of the oxo-scorpionate III were grown from a thf solution of I in the presence of air oxygen at r.t.