Bis(μ2-di­phenyl­phosphinamide-κ2 O:O)bis­[bis(di­phenyl­phosphinamide-κO)lithium] dichloride aceto­nitrile disolvate

Ai-Hong Li; Jun-Ping Han; Jing Li

doi:10.1107/S1600536814011076

. 2014 May 21;70(Pt 6):m224. doi: 10.1107/S1600536814011076

Bis(μ₂-diphenylphosphinamide-κ² O:O)bis[bis(diphenylphosphinamide-κO)lithium] dichloride acetonitrile disolvate

Ai-Hong Li ^a, Jun-Ping Han ^b, Jing Li ^a,^*

PMCID: PMC4051072 PMID: 24940208

Abstract

The asymmetric unit of the title compound, [Li₂(C₁₂H₁₂NOP)₆]Cl₂·2CH₃CN, contains one-half of the centrosymmetric dication, one chloride anion and one acetonitrile solvent molecule. Each Li atom is coordinated by four O atoms [Li—O 1.891 (3) and 2.025 (3) Å] from the four diphenylphosphinamide ligands in a distorted tetrahedral geometry. In the crystal, weak N—H⋯Cl hydrogen bonds link the anions and dications into columns extending along [100].

Related literature

For reviews of related phosphorus–nitrogen transition-metal compounds, see: Roesky & Lucke (1989 ▶); Wong et al. (1997 ▶). For the crystal structures of related compounds, see: Oliva et al. (1981 ▶); Pisareva et al. (2004 ▶).

Experimental

Crystal data

[Li₂(C₁₂H₁₂NOP)₆]Cl₂·2C₂H₃N
M _r = 1470.06
Triclinic,
a = 11.5625 (7) Å
b = 12.5552 (8) Å
c = 13.7686 (9) Å
α = 82.559 (1)°
β = 76.515 (1)°
γ = 89.897 (1)°
V = 1926.5 (2) Å³
Z = 1
Mo Kα radiation
μ = 0.26 mm⁻¹
T = 296 K
0.30 × 0.25 × 0.20 mm

Data collection

Bruker SMART CCD diffractometer
Absorption correction: multi-scan (SADABS; Sheldrick, 1997) ▶ T _min = 0.925, T _max = 0.949
13486 measured reflections
6790 independent reflections
5174 reflections with I > 2σ(I)
R _int = 0.024

Refinement

R[F ² > 2σ(F ²)] = 0.035
wR(F ²) = 0.093
S = 1.01
6790 reflections
452 parameters
H-atom parameters constrained
Δρ_max = 0.25 e Å⁻³
Δρ_min = −0.29 e Å⁻³

Data collection: SMART (Bruker, 2000 ▶); cell refinement: SAINT (Bruker, 2000 ▶); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: SHELXTL/PC (Sheldrick, 2008 ▶); software used to prepare material for publication: SHELXTL/PC.

Supplementary Material

Crystal structure: contains datablock(s) I, New_Global_Publ_Block. DOI: 10.1107/S1600536814011076/cv5450sup1.cif

e-70-0m224-sup1.cif^{(31KB, cif)}

Structure factors: contains datablock(s) I. DOI: 10.1107/S1600536814011076/cv5450Isup2.hkl

e-70-0m224-Isup2.hkl^{(332.3KB, hkl)}

CCDC reference: 1002945

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

Table 1. Hydrogen-bond geometry (Å, °).

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
N1—H1C⋯Cl1ⁱ	0.84	2.61	3.4351 (17)	169
N1—H1D⋯Cl1ⁱⁱ	0.83	2.70	3.4534 (17)	152
N2—H2C⋯Cl1ⁱⁱⁱ	0.83	2.50	3.2789 (18)	158
N2—H2D⋯Cl1^iv	0.84	2.55	3.3776 (18)	169
N3—H3C⋯Cl1^iv	0.88	2.58	3.3967 (19)	154

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

Acknowledgments

This work was carried out under the sponsorship of the National Natural Science Foundation of China (No. 20872084).

supplementary crystallographic information

1. Comment

The π-electron-rich phosphorus-nitrogen compounds had been known as a type of potential precursors for inorganic polymers with unusual properties, and led to considerable interest in their syntheses and coordination chemistry toward transition metals (Roesky & Lucke, 1989; Wong et al., 1997). The title lithium compound is a by-product in the preparation of this type compounds. Treatment of 1,2-dicyanobenzene with the equivalent LiN(SiMe₃)₂ and then the equivalent diphenylphosphinic chloride did not give the π-electron-rich phosphorus-nitrogen compound. The unexpectd title compound was obtained after csystallization in acetonitrile. The crystal structure was ascertained by elemental analysis.

The crystal structure of the compound showed that it has triclinic symmetry. Every lithium ion is coordinated via four oxygen of the ligands to give a tetrahedral geometry. The average bond length of Li—O is 1.945 Å. This value is comparable to the analogous lithium compound (Pisareva et al., 2004). The square-plane ring is formed by the two lithium ion and bridged O atoms in which the bond angle of O1—Li1—O1A is 91.28 (17)°. The average bond length of phosphors-nitrogen in the title compound is 1.623 Å. It is very similar to the bond length of phosphors-nitrogen in the crystal structure of diphenylphosphinamide determined in 1981 (Oliva et al., 1981).

2. Experimental

All reactions were carried out under nitrogen atmosphere in flamed Schlenk-type glassware on a dualmanifold Schlenk line. n-Butyllithium (1.8 cm³, 5 mmol) and NH(SiMe₃)₂ (1.06 cm³, 5 mmol) were dissolveded in THF (20 cm³) at 0°C. The resultant yellow solution was warmed to room temperature and stirred for an additional 2 h. A solution of 1,2-Dicyanobenzene (0.64 g, 5 mmol) in THF (10 cm³) was slowly added to the reaction mixture which was stirred at 0°C for two hours before warming up to room temperature. Then diphenylphosphinic chloride (0.95 cm³,5 mmol) was added to the mixture at -78°C for an hour before warming up to room temperature and allowed to react overnight. Solvent was then removed in vacuum. The residue was extracted with dichloromethane and the solution was filtered. The solvent of the filtrate was removed in vacuum and was dissolveded in CH₃CN at room temperature. Finally a coulourless product was obtained. Yield: 0.43 g, 0.83 mmol, 35%. Elemental analysis cacld (%) for C₇₂H₇₂N₆O₆P₆Li₂Cl₂·0.75CH₃CN·0.25H₂O: C 65.28, H 5.57, N 6.99; found: C 65.12, H 5.50, N 7.05.