(R)-(+)-2,2′-Di­amino-1,1′-bi­naphthyl

The crystal structure of the title compound, C₂₀H₁₆N₂, has been determined at 180 (2) K in the chiral space group P4₃2₁2. The structure is described by a herring-bone close-packing, along the a and b directions, of layers within which intermolecular N—H...π and C—H...π interactions can be found.

Key indicators

• Single-crystal X-ray study
• T = 180 K
• Mean [sigma](C-C) = 0.002 Å
• R factor = 0.036
• wR factor = 0.100
• Data-to-parameter ratio = 9.8

checkCIF results

No syntax errors found

ADDSYM reports no extra symmetry


 Alert Level C:



PLAT_420  Alert C D-H Without Acceptor       N(1)   -   H(1A)             ?

PLAT_420  Alert C D-H Without Acceptor       N(1)   -   H(1B)             ?

General Notes



REFLT_03
         From the CIF: _diffrn_reflns_theta_max           27.49
         From the CIF: _reflns_number_total               1635
         Count of symmetry unique reflns         1092
         Completeness (_total/calc)            149.73%
         TEST3: Check Friedels for noncentro structure
         Estimate of Friedel pairs measured       543
         Fraction of Friedel pairs measured     0.497
         Are heavy atom types Z>Si present           no
          ALERT: MoKa measured Friedel data cannot be used to
                 determine absolute structure in a light-atom
                 study EXCEPT under VERY special conditions.
                 It is preferred that Friedel data is merged in such cases.


 0 Alert Level A = Potentially serious problem

 0 Alert Level B = Potential problem

 2 Alert Level C = Please check

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S1. Comment

We have been focusing our research on the use of amines which can lead to the synthesis of chiral metal complexes with applications, for example, as catalysts in asymmetric hydrogenation processes (Jones et al., 2003a,b,c; Raynor et al., 2000). As part of our study, we came across (R)-2,2'-diamino-1,1'-binaphthyl, (I), an interesting bidentate chiral amine capable of forming chelates with transition metal centres (Mikami, Aikawa & Yusa, 2002; Mikami & Aikawa, 2002; Jones et al., 2003a). Gridunova et al. (1982) have investigated the structure of racemic 2,2'-diamino-1,1'-binaphthyl. Here we report the crystal structure, determined at 180 (2) K, of the pure R form.

Compound (I) crystallizes in the tetragonal chiral space group P4₃2₁2, with the origin located at 2₁12 and the asymmetric unit containing only half of the molecular unit (Fig. 1). Adjacent molecules of (I) are linked by a combination of intermolecular N—H···π and C—H···π interactions [H1B···Cgⁱ = 2.60 (3) Å and N1—H1B···Cgⁱ = 166 (3)°, H5···Cgⁱⁱ = 2.68 Å and C5—H5···Cgⁱⁱ = 159°, where Cg is the centroid of the C4–C9 aromatic ring; symmetry codes: (i) y, −1 + x, −z; (ii) 1/2 + x, 1/2 − y, 1/4 − z] (see Fig. 2). Although one could expect to find a similar N—H···π interaction between the N1—H1A bond and a neighbouring aromatic ring, the spatial arrangement of the molecules does not allow it. Individual molecules of (I) are arranged in the c direction in a way that leads to a herring-bone packing manner (Fig. 3).

S2. Experimental

(R)-(+)-2,2'-Diamino-1,1'-binaphthyl was purchased from Aldrich (99.5% purity) and used without further purification. Crystals suitable for X-Ray diffraction analysis were obtained by recrystallization from methanol.

S3. Refinement

All H atoms bound to C atoms were placed in calculated positions and allowed to ride during subsequent refinement, with U_iso(H) = 1.2U_eq(C). The NH₂ H atoms were located in difference Fourier maps and refined independently. A total of 574 Friedel pairs have been merged and not used as independent data. The corresponding Flack (1983) parameter was found to be meaningless and was omitted.

Computing details

Data collection: COLLECT (Nonius, 1998); cell refinement: HKL SCALEPACK (Otwinowski & Minor, 1997); data reduction: HKL DENZO (Otwinowski & Minor 1997) and SCALEPACK; program(s) used to solve structure: SIR92 (Altomare et al., 1994); program(s) used to refine structure: SHELXTL (Bruker 2001); molecular graphics: SHELXTL; software used to prepare material for publication: SHELXTL.

Figures

	Fig. 1. The molecular structure of (I), showing the labelling scheme for all non-H atoms in the asymmetric unit. Displacement ellipsoids are drawn at the 30% probability level.
	Fig. 2. View of the intermolecular N—H···π and and C—H···π interactions (dashed red lines) between adjacent molecules of (I). Cg is the centroid of the C4–C9 aromatic ring.
	Fig. 3. Perspective view of (I) along the a axis. N—H···π and C—H···π interactions are represented as dashed red lines.

(R)-(+)-2,2'-Diamino-1,1'-binaphthalene

Crystal data

C20H16N2	Dx = 1.268 Mg m^−3
Mr = 284.35	Mo Kα radiation, λ = 0.71073 Å
Tetragonal, P43212	Cell parameters from 4522 reflections
Hall symbol: P 4nw 2abw	θ = 1.0–27.5°
a = 7.0388 (2) Å	µ = 0.08 mm^−1
c = 30.0684 (8) Å	T = 180 K
V = 1489.73 (7) Å^3	Block, colourless
Z = 4	0.46 × 0.46 × 0.23 mm
F(000) = 600

Data collection

Nonius KappaCCD diffractometer	1455 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tube	Rint = 0.029
Thin–slice ω and ϕ scans	θmax = 27.5°, θmin = 3.5°
Absorption correction: multi-scan (SORTAV; Blessing, 1995)	h = −9→9
Tmin = 0.944, Tmax = 0.983	k = −6→9
4236 measured reflections	l = −39→39
1635 independent reflections

Refinement

Refinement on F^2	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F^2 > 2σ(F^2)] = 0.037	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.100	H atoms treated by a mixture of independent and constrained refinement
S = 1.02	w = 1/[σ^2(Fo^2) + (0.0563P)^2 + 0.37P] where P = (Fo^2 + 2Fc^2)/3
1061 reflections	(Δ/σ)max < 0.001
108 parameters	Δρmax = 0.17 e Å^−3
2 restraints	Δρmin = −0.19 e Å^−3

Special details

Experimental. Friedel equivalents merged for refinement. H-atom from –NH2 group have been located in difference Fourier maps. The N–H distance has been restrained to be 0.88 (1) A.

Geometry. All e.s.d.'s (except the e.s.d. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell e.s.d.'s are taken into account individually in the estimation of e.s.d.'s in distances, angles and torsion angles; correlations between e.s.d.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell e.s.d.'s is used for estimating e.s.d.'s involving l.s. planes.

Refinement. Refinement of F² against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F², conventional R-factors R are based on F, with F set to zero for negative F². The threshold expression of F² > σ(F²) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F² are statistically about twice as large as those based on F, and R- factors based on ALL data will be even larger.

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

	x	y	z	Uiso*/Ueq
N1	0.4707 (3)	0.1703 (2)	−0.05183 (5)	0.0366 (4)
H1A	0.368 (2)	0.239 (3)	−0.0574 (8)	0.053 (7)*
H1B	0.457 (4)	0.0482 (16)	−0.0579 (8)	0.067 (8)*
C1	0.5529 (2)	0.2117 (2)	−0.01137 (5)	0.0257 (4)
C2	0.6753 (3)	0.0735 (2)	0.00785 (6)	0.0319 (4)
H2	0.6970	−0.0427	−0.0074	0.038*
C3	0.7617 (2)	0.1046 (3)	0.04747 (6)	0.0303 (4)
H3	0.8408	0.0090	0.0599	0.036*
C4	0.7352 (2)	0.2782 (2)	0.07047 (5)	0.0239 (4)
C5	0.8226 (2)	0.3122 (3)	0.11225 (6)	0.0291 (4)
H5	0.8995	0.2163	0.1253	0.035*
C6	0.7980 (3)	0.4804 (3)	0.13397 (6)	0.0335 (4)
H6	0.8563	0.5006	0.1621	0.040*
C7	0.6859 (3)	0.6244 (3)	0.11468 (6)	0.0328 (4)
H7	0.6703	0.7421	0.1297	0.039*
C8	0.5989 (2)	0.5963 (2)	0.07429 (5)	0.0260 (4)
H8	0.5244	0.6952	0.0617	0.031*
C9	0.6186 (2)	0.4215 (2)	0.05104 (5)	0.0210 (3)
C10	0.5244 (2)	0.3859 (2)	0.00963 (5)	0.0212 (3)

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
N1	0.0516 (11)	0.0268 (8)	0.0314 (8)	0.0000 (8)	−0.0124 (8)	−0.0075 (7)
C1	0.0293 (9)	0.0236 (8)	0.0243 (8)	−0.0021 (7)	−0.0017 (7)	0.0004 (6)
C2	0.0396 (10)	0.0226 (8)	0.0335 (8)	0.0059 (8)	0.0008 (8)	−0.0021 (7)
C3	0.0290 (9)	0.0280 (9)	0.0339 (9)	0.0064 (7)	−0.0016 (8)	0.0076 (8)
C4	0.0194 (7)	0.0292 (8)	0.0231 (8)	−0.0022 (6)	0.0005 (6)	0.0066 (7)
C5	0.0221 (8)	0.0402 (9)	0.0248 (8)	−0.0036 (8)	−0.0024 (7)	0.0101 (7)
C6	0.0311 (9)	0.0475 (11)	0.0218 (8)	−0.0093 (9)	−0.0052 (7)	0.0026 (8)
C7	0.0377 (10)	0.0344 (9)	0.0264 (8)	−0.0074 (8)	−0.0003 (8)	−0.0066 (8)
C8	0.0278 (8)	0.0257 (8)	0.0245 (8)	−0.0020 (7)	−0.0001 (7)	0.0002 (7)
C9	0.0193 (7)	0.0238 (8)	0.0198 (7)	−0.0035 (6)	0.0015 (6)	0.0033 (6)
C10	0.0218 (7)	0.0219 (8)	0.0200 (7)	−0.0011 (6)	0.0003 (6)	0.0028 (6)

Geometric parameters (Å, º)

N1—C1	1.378 (2)	C5—C6	1.363 (3)
N1—H1A	0.884 (10)	C5—H5	0.950
N1—H1B	0.884 (10)	C6—C7	1.409 (3)
C1—C10	1.393 (2)	C6—H6	0.950
C1—C2	1.423 (2)	C7—C8	1.374 (2)
C2—C3	1.355 (2)	C7—H7	0.950
C2—H2	0.950	C8—C9	1.422 (2)
C3—C4	1.417 (2)	C8—H8	0.950
C3—H3	0.950	C9—C10	1.433 (2)
C4—C5	1.419 (2)	C10—C10^i	1.496 (3)
C4—C9	1.426 (2)
C1—N1—H1A	113.1 (15)	C4—C5—H5	119.5
C1—N1—H1B	115.7 (16)	C5—C6—C7	119.91 (16)
H1A—N1—H1B	114 (2)	C5—C6—H6	120.0
N1—C1—C10	121.72 (15)	C7—C6—H6	120.0
N1—C1—C2	117.93 (15)	C8—C7—C6	120.63 (17)
C10—C1—C2	120.30 (15)	C8—C7—H7	119.7
C3—C2—C1	121.25 (16)	C6—C7—H7	119.7
C3—C2—H2	119.4	C7—C8—C9	121.05 (17)
C1—C2—H2	119.4	C7—C8—H8	119.5
C2—C3—C4	120.61 (16)	C9—C8—H8	119.5
C2—C3—H3	119.7	C8—C9—C4	117.82 (14)
C4—C3—H3	119.7	C8—C9—C10	122.26 (14)
C3—C4—C5	121.36 (16)	C4—C9—C10	119.91 (15)
C3—C4—C9	119.09 (15)	C1—C10—C9	118.79 (14)
C5—C4—C9	119.55 (16)	C1—C10—C10^i	119.46 (14)
C6—C5—C4	121.02 (16)	C9—C10—C10^i	121.58 (15)
C6—C5—H5	119.5
N1—C1—C2—C3	179.76 (17)	C3—C4—C9—C8	−178.28 (14)
C10—C1—C2—C3	2.3 (3)	C5—C4—C9—C8	1.6 (2)
C1—C2—C3—C4	−1.3 (3)	C3—C4—C9—C10	2.4 (2)
C2—C3—C4—C5	179.19 (17)	C5—C4—C9—C10	−177.80 (14)
C2—C3—C4—C9	−1.0 (2)	N1—C1—C10—C9	−178.22 (15)
C3—C4—C5—C6	179.34 (16)	C2—C1—C10—C9	−0.8 (2)
C9—C4—C5—C6	−0.5 (2)	N1—C1—C10—C10^i	6.4 (2)
C4—C5—C6—C7	−0.7 (3)	C2—C1—C10—C10^i	−176.20 (14)
C5—C6—C7—C8	0.8 (3)	C8—C9—C10—C1	179.22 (14)
C6—C7—C8—C9	0.3 (3)	C4—C9—C10—C1	−1.5 (2)
C7—C8—C9—C4	−1.5 (2)	C8—C9—C10—C10^i	−5.5 (2)
C7—C8—C9—C10	177.85 (15)	C4—C9—C10—C10^i	173.83 (12)

Symmetry code: (i) y, x, −z.