Bis­[μ-2-(phenyl­amido)­pyridine]­bis­{[2-(phenyl­amino)­pyridine]­lithium(I)}

The title complex, [Li(PhN-2-C₅H₄N)(PhNH-2-C₅H₄N)]₂ or [Li₂(C₁₁H₉N₂)₂(C₁₁H₁₀N₂)₂], is centrosymmetric with a central Li₂N₂ ring formed by two amide ligands bridging the two Li⁺ centres. Each amide ligand also coordinates through its pyridine N atom to one of the Li⁺ cations, giving LiNCN chelate four-membered rings. Each neutral amine ligand coordinates terminally to one Li⁺ cation and forms an intramolecular N—H⋯N hydrogen bond by donation from its amine group to the bridging amido N atom of one of the amide ligands. The coordination of Li is distorted tetrahedral by two bridging amido and two pyridyl N atoms. The complex is the product of partial deprotonation of 2-phenyl­amino­pyridine by alkyl­lithium reagents, the remaining amine NH groups being sterically inaccessible even to strong bases.

Comment

The anion L⁻ of 2-phenyl­amino­pyridine (HL) has been extensively used as a ligand in transition metal chemistry. Its two N atoms can be used to bridge pairs of metal ions or to chelate a single metal ion. The Cambridge Structural Database (CSD, Version 5.25, with updates to April 2004; Allen, 2002) contains over 30 examples of the former type of complex and ten of the latter. Its use in complexes of main-group metals has been more restricted. The 20 structures in the CSD include three with aluminium, nine with alkali metals, and the others contain two metals (Li and Zn, or Li and Al). In these complexes, the ligand displays a variety of chelating and bridging modes, with attachment to as many as four metal centres. Some of the lithium complexes are fascinating clusters encapsulating hydride anions (Armstrong et al., 1999). We have recently reported some structures in which the anion remains uncoordinated to alkali metal cations, which are sandwiched by crown ethers to generate separated ion-pair complexes (Liddle et al., 2004).

In our previous work with this ligand, we found that it was surprisingly difficult to deprotonate it fully by treatment with alkyl­lithium reagents. In many reactions, the product contained equal amounts of the desired anion and the parent amine, often linked together by an N—H⋯N hydrogen bond. Various attempts to overcome this reluctance of the amine to full stoichiometric deprotonation included metathesis reactions in which a complex of the fully deprotonated ligand with a different alkali metal was treated with a compound of lithium. In order to generate the complex [(15-crown-5)₂Li]⁺·L⁻, the corresponding potassium salt was treated with lithium iodide in THF solution. The title complex was the unexpected solid product, in low yield (ca 20%), indicating that other unidentified products remained in solution.

After determining its crystal structure, we discovered that the same complex had been prepared previously by Polamo & Leskelä (1996), who also determined its structure. It is of interest that their synthesis was also unintentional (in an attempt to produce a zirconium complex), and that it represents another half-deprotonation of HL by butyl­lithium. We report the results of our work here because the structure is of significantly higher precision and in order to compare the structure with those of related compounds, some of which have only recently been published.

The title complex, (I), is dimeric and centrosymmetric (Fig. 1). Two L⁻ ligands act as bridges between two Li⁺ cations, through their amido N atoms, to give a central four-membered Li₂N₂ ring, a common feature in structural lithium amide chemistry. The pyridine N atom of each bridging ligand coordinates to one lithium centre, generating a four-membered LiNCN chelate ring. Distorted tetrahedral coord­ination of each Li⁺ is completed by terminal attachment of the pyridine N atoms of a neutral LH mol­ecule, the NH group of which is hydrogen bonded to one of the bridging amido N atoms (Tables 1 and 2).

The combined chelating and bridging functions of the anionic ligand L⁻ and the combination of coordination and hydrogen bonding for the neutral ligand HL bring both of these ligands into a syn arrangement of the two N atoms, in contrast to the preferred anti arrangement for the uncomplexed anion (Liddle et al., 2004). The syn arrangement, unlike the anti arrangement, does not permit coplanarity of the two rings, because of unfavourable steric interaction of H atoms, so the phenyl ring is twisted around the N—C bond, well out of the mean plane of the rest of the ligand [dihedral angles are 51.39 (3) and 53.45 (4)° for L⁻ and HL, respectively, in the title complex]. A similar effect has been seen for other chelate complexes of L⁻ (Liddle et al., 2004) and for uncomplexed HL (Polamo et al., 1997), which forms a hydrogen-bonded dimer.

A relatively strong hydrogen bond between HL and L⁻ occurs also in the complexes [(12-crown-4)₂M]⁺[L·HL]⁻, with M = Li, Na, K (Liddle & Clegg, 2003). The lithium complex in this series was also obtained as an unexpected product of partial li­thia­tion of HL and has the hydrogen-bonded [L·HL]⁻ unit as an uncoordinated anion; the sodium and potassium complexes were generated from it by metathesis reactions. The same behaviour was observed 20 years ago by Barr et al. (1984a), also in a lithium complex, [{(Me₂N)₃PO}Li(L)(HL)], which was first obtained as a minor product in the synthesis of [{(Me₂N)₃PO}Li(L)]₂ (Barr et al., 1984b) and subsequently in a targeted synthesis with reagents in the appropriate stoichiometry. As in the title complex, the hydrogen-bonded combination of coordinated L⁻ and HL ligands here necessarily involves a short Li⋯H contact, but this should probably not be regarded as a direct interaction, of the agostic kind or otherwise. The apparent tendency of HL and L⁻ to associate by hydrogen bonding does, however, seem to be linked to the failure of organolithium reagents to deprotonate HL completely in these reactions, and may be the cause rather than a result of this, the N—H⋯N proton being thereby shielded from attack by the base. The inaccessibility of this site is demonstrated by the space-filling representation in Fig. 2, where the amine H atom is barely visible; this is true in all directions of view.

Figure 1 The molecular structure of (I) with atom labels and 50% probability ellipsoids. H atoms, except for those involved in hydrogen bonding, have been omitted. Hydro­gen bonds are shown as dashed lines. Unlabelled atoms are related to the labelled atoms by the symmetry code (1 − x, 1 − y, 1z − z.

Figure 2 Space-filling representation of (I), including H atoms. The amine H atom is barely visible, next to its N atom and an Li atom.

Experimental

A solution of [(15-crown-5)₂K]L (Liddle et al., 2004) (0.89 g, 1.38 mmol) in THF (50 ml) was added to solid LiI (0.18 g, 1.38 mmol), giving a turbid yellow solution, which was stirred for one day. The solution was filtered and volatile materials removed in vacuo, to give a dark orange oil. Recrystallization from toluene yielded crystals of the title compound (0.05 g, 21%).

Crystal data

• [Li₂(C₁₁H₉N₂)₂(C₁₁H₁₀N₂)₂]

• M_r = 692.70

• Triclinic, 

• a = 8.7031 (8) Å

• b = 10.3718 (10) Å

• c = 11.5289 (11) Å

• α = 116.715 (2)°

• β = 92.739 (2)°

• γ = 91.216 (2)°

• V = 927.46 (15) ų

• Z = 1

• D_x = 1.240 Mg m⁻³

• Mo Kα radiation

• Cell parameters from 3543 reflections

• θ = 2.2–28.5°

• μ = 0.08 mm⁻¹

• T = 160 (2) K

• Plate, yellow

• 0.70 × 0.52 × 0.08 mm

Data collection

• Bruker SMART 1 K CCD diffractometer

• Thin-slice ω scans

• Absorption correction: none

• 5683 measured reflections

• 4165 independent reflections

• 2868 reflections with I > 2σ(I)

• R_int = 0.014

• θ_max = 28.6°

• h = −11 → 11

• k = −13 → 11

• l = −14 → 14

Refinement

• Refinement on F²

• R[F² > 2σ(F²)] = 0.040

• wR(F²) = 0.102

• S = 0.92

• 4165 reflections

• 321 parameters

• All H-atom parameters refined

• w = 1/[σ²(F_o²) + (0.0563P)²] where P = (F_o² + 2F_c²)/3

• (Δ/σ)_max < 0.001

• Δρ_max = 0.23 e Å⁻³

• Δρ_min = −0.20 e Å⁻³

• Extinction correction: SHELXTL

• Extinction coefficient: 0.011 (3)

Table 1
Selected geometric parameters (Å, °)

Li—N1	2.036 (3)
Li—N2	2.187 (3)
Li—N2^i	2.022 (3)
Li—N3	2.002 (3)

N1—Li—N2	65.19 (8)
N1—Li—N2^i	118.30 (13)
N1—Li—N3	112.43 (13)
N2—Li—N2^i	110.67 (12)
N2—Li—N3	120.85 (13)
N2^i—Li—N3	118.54 (12)
Symmetry code: (i) 1-x,1-y,1-z.

Table 2
Hydrogen-bonding geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
N4—H4N⋯N2^i	0.900 (16)	2.288 (17)	3.1763 (16)	169.1 (13)
Symmetry code: (i) 1-x,1-y,1-z.

All H atoms were located in a difference Fourier synthesis and refined with individual isotropic displacement parameters. C—H distances are in the range 0.916 (17)–0.992 (17) Å, and the unique N—H distance is 0.900 (16) Å.

Data collection: SMART (Bruker, 2001); cell refinement: SAINT (Bruker, 2001); data reduction: SAINT; program(s) used to solve structure: SHELXTL (Sheldrick, 2001); program(s) used to refine structure: SHELXTL; molecular graphics: SHELXTL; software used to prepare material for publication: SHELXTL and local programs.

Supporting information

Computing details

Data collection: SMART (Bruker, 2001); cell refinement: SAINT (Bruker, 2001); data reduction: SAINT; program(s) used to solve structure: SHELXTL (Sheldrick, 2001); program(s) used to refine structure: SHELXTL; molecular graphics: SHELXTL; software used to prepare material for publication: SHELXTL and local programs.

Bis[µ-2-(phenylamido)pyridine]bis{[2-(phenylamino)pyridine]lithium(I)}

Crystal data

[Li2(C11H9N2)2(C11H10N2)2]	Z = 1
Mr = 692.70	F(000) = 364
Triclinic, P1	Dx = 1.240 Mg m^−3
a = 8.7031 (8) Å	Mo Kα radiation, λ = 0.71073 Å
b = 10.3718 (10) Å	Cell parameters from 3543 reflections
c = 11.5289 (11) Å	θ = 2.2–28.5°
α = 116.715 (2)°	µ = 0.08 mm^−1
β = 92.739 (2)°	T = 160 K
γ = 91.216 (2)°	Plate, yellow
V = 927.46 (15) Å^3	0.70 × 0.52 × 0.08 mm

Data collection

Bruker SMART 1K CCD diffractometer	2868 reflections with I > 2σ(I)
Radiation source: sealed tube	Rint = 0.014
Graphite monochromator	θmax = 28.6°, θmin = 2.0°
Detector resolution: 8.192 pixels mm^-1	h = −11→11
thin–slice ω scans	k = −13→11
5683 measured reflections	l = −14→14
4165 independent reflections

Refinement

Refinement on F^2	Secondary atom site location: difference Fourier map
Least-squares matrix: full	Hydrogen site location: difference Fourier map
R[F^2 > 2σ(F^2)] = 0.040	All H-atom parameters refined
wR(F^2) = 0.102	w = 1/[σ^2(Fo^2) + (0.0563P)^2] where P = (Fo^2 + 2Fc^2)/3
S = 0.92	(Δ/σ)max < 0.001
4165 reflections	Δρmax = 0.23 e Å^−3
321 parameters	Δρmin = −0.20 e Å^−3
0 restraints	Extinction correction: SHELXTL, Fc^*=kFc[1+0.001xFc^2λ^3/sin(2θ)]^-1/4
Primary atom site location: structure-invariant direct methods	Extinction coefficient: 0.011 (3)

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Ų)

	x	y	z	Uiso*/Ueq
Li	0.3855 (3)	0.5671 (3)	0.5221 (2)	0.0406 (6)
N1	0.27806 (13)	0.42171 (12)	0.56848 (11)	0.0317 (3)
N2	0.52228 (12)	0.50692 (11)	0.65280 (10)	0.0264 (2)
C1	0.14004 (17)	0.36108 (15)	0.56935 (15)	0.0357 (3)
H1	0.0743 (18)	0.3379 (16)	0.4933 (15)	0.044 (4)*
C2	0.09729 (17)	0.33301 (16)	0.66845 (15)	0.0372 (3)
H2	−0.0035 (19)	0.2903 (16)	0.6635 (15)	0.045 (4)*
C3	0.20271 (18)	0.36851 (16)	0.77320 (15)	0.0395 (4)
H3	0.1773 (19)	0.3497 (17)	0.8474 (16)	0.056 (5)*
C4	0.34521 (17)	0.42868 (15)	0.77534 (14)	0.0338 (3)
H4	0.4166 (18)	0.4513 (16)	0.8458 (14)	0.040 (4)*
C5	0.38331 (15)	0.45526 (13)	0.67015 (12)	0.0253 (3)
C6	0.62527 (15)	0.58820 (13)	0.76016 (12)	0.0251 (3)
C7	0.58101 (17)	0.68904 (15)	0.88262 (13)	0.0327 (3)
H7	0.4730 (19)	0.7012 (16)	0.8940 (14)	0.043 (4)*
C8	0.68913 (18)	0.76838 (16)	0.98206 (14)	0.0386 (4)
H8	0.6545 (18)	0.8382 (17)	1.0639 (15)	0.048 (4)*
C9	0.84486 (18)	0.75217 (16)	0.96387 (14)	0.0381 (4)
H9	0.9204 (17)	0.8091 (15)	1.0341 (14)	0.038 (4)*
C10	0.89026 (17)	0.65500 (15)	0.84356 (14)	0.0355 (3)
H10	1.0009 (19)	0.6393 (16)	0.8305 (15)	0.047 (4)*
C11	0.78262 (16)	0.57577 (14)	0.74348 (13)	0.0293 (3)
H11	0.8158 (19)	0.5099 (17)	0.6655 (16)	0.051 (5)*
N3	0.28231 (13)	0.75574 (11)	0.59060 (11)	0.0314 (3)
N4	0.33760 (14)	0.79794 (13)	0.41807 (11)	0.0323 (3)
H4N	0.3784 (19)	0.7106 (17)	0.3870 (15)	0.046 (4)*
C12	0.20863 (18)	0.78881 (16)	0.69984 (14)	0.0370 (3)
H12	0.2276 (17)	0.7254 (16)	0.7419 (14)	0.042 (4)*
C13	0.11184 (19)	0.90076 (15)	0.75203 (14)	0.0385 (4)
H13	0.065 (2)	0.9179 (17)	0.8293 (16)	0.051 (5)*
C14	0.09143 (18)	0.98592 (15)	0.68881 (14)	0.0370 (3)
H14	0.0199 (19)	1.0660 (17)	0.7219 (15)	0.047 (4)*
C15	0.16715 (16)	0.95821 (14)	0.57888 (14)	0.0333 (3)
H15	0.1526 (17)	1.0182 (16)	0.5340 (14)	0.041 (4)*
C16	0.26182 (15)	0.84025 (13)	0.53066 (12)	0.0278 (3)
C17	0.31804 (15)	0.85230 (14)	0.32528 (13)	0.0306 (3)
C18	0.34383 (18)	0.99792 (17)	0.35960 (17)	0.0407 (4)
H18	0.3774 (18)	1.0631 (17)	0.4482 (15)	0.044 (4)*
C19	0.3265 (2)	1.0454 (2)	0.2653 (2)	0.0527 (5)
H19	0.347 (2)	1.144 (2)	0.2929 (18)	0.074 (6)*
C20	0.2847 (2)	0.9495 (2)	0.13783 (19)	0.0540 (5)
H20	0.271 (2)	0.9811 (19)	0.0716 (18)	0.066 (5)*
C21	0.26074 (18)	0.8049 (2)	0.10362 (17)	0.0455 (4)
H21	0.229 (2)	0.7353 (18)	0.0125 (17)	0.056 (5)*
C22	0.27653 (16)	0.75598 (17)	0.19709 (14)	0.0354 (3)
H22	0.2593 (18)	0.6514 (17)	0.1689 (15)	0.047 (4)*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Li	0.0473 (15)	0.0401 (13)	0.0407 (14)	0.0186 (11)	0.0176 (11)	0.0217 (11)
N1	0.0314 (6)	0.0335 (6)	0.0311 (6)	0.0035 (5)	0.0012 (5)	0.0154 (5)
N2	0.0263 (6)	0.0302 (6)	0.0232 (5)	0.0040 (5)	0.0053 (4)	0.0119 (4)
C1	0.0318 (8)	0.0343 (8)	0.0403 (8)	0.0017 (6)	−0.0029 (7)	0.0168 (7)
C2	0.0301 (8)	0.0339 (8)	0.0502 (9)	0.0019 (6)	0.0064 (7)	0.0209 (7)
C3	0.0409 (9)	0.0439 (9)	0.0432 (9)	0.0010 (7)	0.0089 (7)	0.0275 (7)
C4	0.0344 (8)	0.0402 (8)	0.0330 (8)	0.0019 (6)	0.0020 (6)	0.0220 (6)
C5	0.0279 (7)	0.0228 (6)	0.0253 (6)	0.0082 (5)	0.0052 (5)	0.0104 (5)
C6	0.0288 (7)	0.0243 (6)	0.0255 (6)	0.0047 (5)	0.0039 (5)	0.0138 (5)
C7	0.0317 (8)	0.0351 (8)	0.0293 (7)	0.0073 (6)	0.0065 (6)	0.0121 (6)
C8	0.0449 (9)	0.0379 (8)	0.0267 (7)	0.0059 (7)	0.0057 (7)	0.0086 (6)
C9	0.0405 (9)	0.0359 (8)	0.0326 (8)	−0.0028 (7)	−0.0047 (7)	0.0118 (6)
C10	0.0300 (8)	0.0348 (8)	0.0415 (8)	0.0013 (6)	0.0041 (6)	0.0168 (7)
C11	0.0315 (7)	0.0278 (7)	0.0274 (7)	0.0044 (6)	0.0078 (6)	0.0107 (6)
N3	0.0362 (7)	0.0288 (6)	0.0312 (6)	0.0097 (5)	0.0056 (5)	0.0146 (5)
N4	0.0381 (7)	0.0291 (6)	0.0334 (6)	0.0125 (5)	0.0082 (5)	0.0164 (5)
C12	0.0473 (9)	0.0337 (7)	0.0330 (8)	0.0100 (7)	0.0082 (7)	0.0168 (6)
C13	0.0487 (9)	0.0341 (8)	0.0308 (8)	0.0105 (7)	0.0117 (7)	0.0116 (6)
C14	0.0403 (9)	0.0297 (7)	0.0358 (8)	0.0114 (6)	0.0057 (7)	0.0095 (6)
C15	0.0374 (8)	0.0276 (7)	0.0341 (8)	0.0081 (6)	0.0025 (6)	0.0129 (6)
C16	0.0288 (7)	0.0252 (6)	0.0272 (7)	0.0023 (5)	−0.0003 (5)	0.0100 (5)
C17	0.0239 (7)	0.0359 (7)	0.0390 (8)	0.0061 (6)	0.0061 (6)	0.0224 (6)
C18	0.0387 (9)	0.0379 (8)	0.0502 (10)	0.0014 (7)	0.0030 (7)	0.0240 (8)
C19	0.0492 (10)	0.0510 (10)	0.0795 (14)	0.0085 (8)	0.0151 (9)	0.0473 (10)
C20	0.0481 (10)	0.0799 (13)	0.0637 (12)	0.0216 (9)	0.0189 (9)	0.0564 (11)
C21	0.0372 (9)	0.0666 (11)	0.0411 (9)	0.0151 (8)	0.0113 (7)	0.0304 (9)
C22	0.0308 (8)	0.0410 (8)	0.0386 (8)	0.0096 (6)	0.0097 (6)	0.0207 (7)

Geometric parameters (Å, º)

Li—N1	2.036 (3)	C10—C11	1.3768 (19)
Li—N2	2.187 (3)	C11—H11	0.916 (17)
Li—N2^i	2.022 (3)	N3—C12	1.3465 (18)
Li—N3	2.002 (3)	N3—C16	1.3481 (16)
N1—C1	1.3466 (18)	N4—H4N	0.900 (16)
N1—C5	1.3606 (16)	N4—C16	1.3764 (17)
N2—Li^i	2.022 (3)	N4—C17	1.4213 (16)
N2—C5	1.3718 (17)	C12—H12	0.989 (14)
N2—C6	1.4035 (15)	C12—C13	1.372 (2)
C1—H1	0.954 (15)	C13—H13	0.942 (17)
C1—C2	1.365 (2)	C13—C14	1.384 (2)
C2—H2	0.962 (16)	C14—H14	0.991 (17)
C2—C3	1.384 (2)	C14—C15	1.372 (2)
C3—H3	0.992 (17)	C15—H15	0.978 (14)
C3—C4	1.371 (2)	C15—C16	1.3999 (18)
C4—H4	0.936 (15)	C17—C18	1.3885 (19)
C4—C5	1.4113 (18)	C17—C22	1.385 (2)
C6—C7	1.4061 (18)	C18—H18	0.963 (15)
C6—C11	1.3926 (18)	C18—C19	1.384 (2)
C7—H7	0.959 (17)	C19—H19	0.934 (19)
C7—C8	1.376 (2)	C19—C20	1.379 (3)
C8—H8	0.963 (17)	C20—H20	0.961 (18)
C8—C9	1.384 (2)	C20—C21	1.378 (2)
C9—H9	0.969 (14)	C21—H21	0.992 (17)
C9—C10	1.381 (2)	C21—C22	1.385 (2)
C10—H10	0.988 (17)	C22—H22	0.988 (16)
N1—Li—N2	65.19 (8)	H10—C10—C11	119.8 (9)
N1—Li—N2^i	118.30 (13)	C6—C11—C10	121.60 (13)
N1—Li—N3	112.43 (13)	C6—C11—H11	119.4 (10)
N2—Li—N2^i	110.67 (12)	C10—C11—H11	118.9 (10)
N2—Li—N3	120.85 (13)	Li—N3—C12	114.62 (11)
N2^i—Li—N3	118.54 (12)	Li—N3—C16	127.06 (11)
Li—N1—C1	143.87 (12)	C12—N3—C16	117.65 (12)
Li—N1—C5	90.45 (11)	H4N—N4—C16	116.2 (10)
C1—N1—C5	119.05 (12)	H4N—N4—C17	114.3 (10)
Li—N2—Li^i	69.33 (12)	C16—N4—C17	126.39 (12)
Li—N2—C5	84.03 (10)	N3—C12—H12	115.4 (9)
Li^i—N2—C5	123.09 (12)	N3—C12—C13	124.16 (13)
Li—N2—C6	131.59 (11)	H12—C12—C13	120.4 (9)
Li^i—N2—C6	114.85 (11)	C12—C13—H13	119.4 (10)
C5—N2—C6	120.29 (10)	C12—C13—C14	117.42 (14)
N1—C1—H1	113.8 (9)	H13—C13—C14	123.2 (10)
N1—C1—C2	123.67 (14)	C13—C14—H14	119.8 (9)
H1—C1—C2	122.5 (9)	C13—C14—C15	120.38 (14)
C1—C2—H2	119.6 (9)	H14—C14—C15	119.8 (9)
C1—C2—C3	117.76 (14)	C14—C15—H15	120.4 (9)
H2—C2—C3	122.7 (9)	C14—C15—C16	118.60 (13)
C2—C3—H3	120.8 (9)	H15—C15—C16	120.9 (9)
C2—C3—C4	120.40 (14)	N3—C16—N4	114.41 (12)
H3—C3—C4	118.8 (10)	N3—C16—C15	121.77 (12)
C3—C4—H4	120.1 (9)	N4—C16—C15	123.79 (12)
C3—C4—C5	119.42 (13)	N4—C17—C18	121.58 (13)
H4—C4—C5	120.5 (9)	N4—C17—C22	118.64 (12)
N1—C5—N2	113.04 (11)	C18—C17—C22	119.76 (13)
N1—C5—C4	119.68 (12)	C17—C18—H18	119.0 (9)
N2—C5—C4	127.20 (12)	C17—C18—C19	119.53 (16)
N2—C6—C7	124.44 (12)	H18—C18—C19	121.4 (9)
N2—C6—C11	118.43 (11)	C18—C19—H19	116.3 (11)
C7—C6—C11	117.00 (12)	C18—C19—C20	120.70 (16)
C6—C7—H7	117.7 (9)	H19—C19—C20	123.0 (11)
C6—C7—C8	121.09 (14)	C19—C20—H20	121.6 (11)
H7—C7—C8	121.2 (9)	C19—C20—C21	119.73 (15)
C7—C8—H8	118.7 (10)	H20—C20—C21	118.6 (11)
C7—C8—C9	120.83 (14)	C20—C21—H21	120.4 (10)
H8—C8—C9	120.4 (10)	C20—C21—C22	120.21 (16)
C8—C9—H9	120.4 (9)	H21—C21—C22	119.3 (10)
C8—C9—C10	118.78 (14)	C17—C22—C21	120.07 (15)
H9—C9—C10	120.8 (9)	C17—C22—H22	122.0 (9)
C9—C10—H10	119.5 (9)	C21—C22—H22	118.0 (9)
C9—C10—C11	120.66 (14)
N2—Li—N1—C1	162.8 (2)	N2—C6—C7—C8	−177.74 (12)
N2^i—Li—N1—C1	−96.1 (2)	C11—C6—C7—C8	−1.82 (19)
N2—Li—N1—C5	16.23 (8)	C6—C7—C8—C9	0.7 (2)
N2^i—Li—N1—C5	117.34 (14)	C7—C8—C9—C10	0.2 (2)
N3—Li—N1—C1	47.9 (3)	C8—C9—C10—C11	0.1 (2)
N3—Li—N1—C5	−98.63 (14)	C9—C10—C11—C6	−1.3 (2)
N1—Li—N2—Li^i	112.58 (14)	N2—C6—C11—C10	178.31 (11)
N1—Li—N2—C5	−16.18 (8)	C7—C6—C11—C10	2.13 (19)
N1—Li—N2—C6	−142.01 (12)	N1—Li—N3—C12	28.69 (19)
N2^i—Li—N2—Li^i	0.0	N1—Li—N3—C16	−141.62 (13)
N2^i—Li—N2—C5	−128.76 (14)	N2—Li—N3—C12	−44.9 (2)
N2^i—Li—N2—C6	105.42 (15)	N2^i—Li—N3—C12	172.62 (14)
N3—Li—N2—Li^i	−145.1 (2)	N2—Li—N3—C16	144.76 (13)
N3—Li—N2—C5	86.15 (15)	N2^i—Li—N3—C16	2.3 (2)
N3—Li—N2—C6	−39.7 (2)	Li—N3—C12—C13	−169.80 (15)
Li—N1—C1—C2	−139.68 (19)	C16—N3—C12—C13	1.5 (2)
C5—N1—C1—C2	1.2 (2)	N3—C12—C13—C14	−1.1 (2)
N1—C1—C2—C3	−0.3 (2)	C12—C13—C14—C15	−0.5 (2)
C1—C2—C3—C4	−0.5 (2)	C13—C14—C15—C16	1.6 (2)
C2—C3—C4—C5	0.5 (2)	Li—N3—C16—N4	−8.5 (2)
Li—N1—C5—N2	−26.08 (12)	Li—N3—C16—C15	169.81 (14)
Li—N1—C5—C4	156.96 (13)	C12—N3—C16—N4	−178.51 (12)
C1—N1—C5—N2	175.75 (12)	C12—N3—C16—C15	−0.25 (19)
C1—N1—C5—C4	−1.21 (19)	C17—N4—C16—N3	169.57 (12)
Li—N2—C5—N1	24.30 (12)	C17—N4—C16—C15	−8.6 (2)
Li^i—N2—C5—N1	−36.25 (17)	C14—C15—C16—N3	−1.3 (2)
Li—N2—C5—C4	−159.01 (15)	C14—C15—C16—N4	176.84 (13)
Li^i—N2—C5—C4	140.44 (14)	C16—N4—C17—C18	58.73 (19)
C6—N2—C5—N1	159.69 (10)	C16—N4—C17—C22	−123.15 (15)
C6—N2—C5—C4	−23.63 (19)	N4—C17—C18—C19	178.61 (14)
C3—C4—C5—N1	0.4 (2)	C22—C17—C18—C19	0.5 (2)
C3—C4—C5—N2	−176.10 (14)	C17—C18—C19—C20	−0.3 (2)
Li—N2—C6—C7	73.60 (18)	C18—C19—C20—C21	−0.4 (3)
Li^i—N2—C6—C7	157.34 (13)	C19—C20—C21—C22	0.8 (2)
Li—N2—C6—C11	−102.27 (15)	C20—C21—C22—C17	−0.6 (2)
Li^i—N2—C6—C11	−18.53 (15)	N4—C17—C22—C21	−178.20 (13)
C5—N2—C6—C7	−37.35 (18)	C18—C17—C22—C21	0.0 (2)
C5—N2—C6—C11	146.78 (12)

Symmetry code: (i) −x+1, −y+1, −z+1.

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
N4—H4N···N2^i	0.900 (16)	2.288 (17)	3.1763 (16)	169.1 (13)

Symmetry code: (i) −x+1, −y+1, −z+1.

 

Footnotes

‡Current address: School of Chemistry, University of Nottingham, University Park, Nottingham NG7 2RD, England