1,1'-Methyl­enebis(naphthalen-2-amine) methanol solvate

In the title compound, C₂₁H₁₈N₂·CH₄O, the two naphthyl ring systems are arranged almost orthogonal to one another, with a dihedral angle of 89.8 (1)°.

Key indicators

• Single-crystal X-ray study
• T = 294 K
• Mean [sigma](C-C) = 0.005 Å
• H-atom completeness 82%
• Disorder in solvent or counterion
• R factor = 0.049
• wR factor = 0.065
• Data-to-parameter ratio = 6.1

checkCIF/PLATON results

No syntax errors found



Alert level A
DIFF012_ALERT_1_A  _diffrn_reflns_av_R_equivalents is missing
            R factor for symmetry-equivalent intensities.
            The following tests will not be performed
            RINTA

Author Response: The error (?) exists because there were no symmetry equivalent reflections measured. Being orthorhombic, only one octant of reflections is necessary to get a complete set.

Alert level C
ABSMU01_ALERT_1_C  The ratio of given/expected absorption coefficient lies
               outside the range 0.99 <> 1.01
            Calculated value of mu =     0.079
            Value of mu given      =     0.078
CHEMW03_ALERT_2_C The ratio of given/expected molecular weight as
            calculated from the _atom_site* data lies outside
            the range 0.99 <> 1.01
           From the CIF: _cell_formula_units_Z                    4
           From the CIF: _chemical_formula_weight           330.40
           TEST: Calculate formula weight from _atom_site_*
           atom     mass    num     sum
           N        14.01    2.00   28.01
           C        12.01   22.00  264.24
           O        16.00    1.00   16.00
           H         1.01   18.00   18.14
           Calculated formula weight              326.40
REFNR01_ALERT_3_C  Ratio of reflections to parameters is < 8 for a
            non-centrosymmetric structure, where ZMAX < 18
            sine(theta)/lambda                0.5946
            Proportion of unique data used    0.8461
            Ratio reflections to parameters   6.1017
PLAT041_ALERT_1_C Calc. and Rep. SumFormula Strings    Differ ....          ?
PLAT042_ALERT_1_C Calc. and Rep. MoietyFormula Strings Differ ....          ?
PLAT043_ALERT_1_C Check Reported Molecular Weight ................     330.40
PLAT044_ALERT_1_C Calculated and Reported Dx Differ ..............          ?
PLAT068_ALERT_1_C Reported F000 Differs from Calcd (or Missing)...          ?
PLAT089_ALERT_3_C Poor Data / Parameter Ratio (Zmax .LT. 18) .....       6.10
PLAT152_ALERT_1_C Supplied and Calc Volume s.u. Inconsistent .....          ?
PLAT163_ALERT_4_C Missing or Zero su (esd) on z-coordinate for ...         N1
PLAT302_ALERT_4_C Anion/Solvent Disorder .........................      33.00 Perc.
PLAT340_ALERT_3_C Low Bond Precision on C-C Bonds (x 1000) Ang ...          5
PLAT410_ALERT_2_C Short Intra H...H Contact  HC8    ..  H1C11   ..       1.90 Ang.
PLAT410_ALERT_2_C Short Intra H...H Contact  HC8    ..  H1C11   ..       1.90 Ang.
PLAT420_ALERT_2_C D-H Without Acceptor       N1     -   H2N1   ...          ?
PLAT720_ALERT_4_C Number of Unusual/Non-Standard Label(s) ........         12

Alert level G
FORMU01_ALERT_2_G  There is a discrepancy between the atom counts in the
            _chemical_formula_sum and the formula from the _atom_site* data.
            Atom count from _chemical_formula_sum:C22 H22 N2 O1
            Atom count from the _atom_site data:  C22 H18 N2 O1
CELLZ01_ALERT_1_G Difference between formula and atom_site contents detected.
CELLZ01_ALERT_1_G WARNING: H atoms missing from atom site list. Is this intentional?
           From the CIF: _cell_formula_units_Z    4
           From the CIF: _chemical_formula_sum  C22 H22 N2 O
           TEST: Compare cell contents of formula and atom_site data

           atom    Z*formula  cif sites diff
           C         88.00     88.00    0.00
           H         88.00     72.00   16.00
           N          8.00      8.00    0.00
           O          4.00      4.00    0.00
REFLT03_ALERT_4_G Please check that the estimate of the number of Friedel pairs is
            correct. If it is not, please give the correct count in the
            _publ_section_exptl_refinement section of the submitted CIF.
           From the CIF: _diffrn_reflns_theta_max           25.00
           From the CIF: _reflns_number_total                851
           Count of symmetry unique reflns          856
           Completeness (_total/calc)             99.42%
           TEST3: Check Friedels for noncentro structure
           Estimate of Friedel pairs measured         0
           Fraction of Friedel pairs measured     0.000
           Are heavy atom types Z>Si present         no

   1 ALERT level A = In general: serious problem
   0 ALERT level B = Potentially serious problem
  17 ALERT level C = Check and explain
   4 ALERT level G = General alerts; check

  10 ALERT type 1 CIF construction/syntax error, inconsistent or missing data
   5 ALERT type 2 Indicator that the structure model may be wrong or deficient
   3 ALERT type 3 Indicator that the structure quality may be low
   4 ALERT type 4 Improvement, methodology, query or suggestion
   0 ALERT type 5 Informative message, check

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S1. Comment

The syntheses of methylene bridged aromatic amines have been the subject of over 40 patents during the past 40 years, however, to the best of our knowledge the synthesis of (I) has not been previously reported. Compound (I) was obtained as an unexpected by-product in the removal of the apical methylene strap from naphthalene Tröger's base (Farrar, 1964; Tálas et al., 1998) using trifluoroacetic anhydride (Miyahara et al., 1999) as outlined in Fig. 2. Dinitrated analogues of (I), and various isomers thereof, have been reported (Morgan & Jones, 1923) and benzo analogues (Partridge & Vipond, 1962) have been used in the synthesis of organometallic complexes (Gibson et al., 1996) The asymmetric unit contains one half molecule of (I) and one half molecule of methanol, i.e., it is a 1:1 composition. The two naphthalene rings of (I) are oriented at almost 90 ° with respect to one another, and they are aligned in an anti-parallel fashion, such that the the two amino substituents are projected in opposite directions.

The molecular structure of (I) is shown in Fig. 1.

Related literature

For related literature, see: Farrar (1964); Gibson et al. (1996); Ibers & Hamilton (1974); Miyahara et al. (1999); Morgan & Jones (1923); Partridge & Vipond (1962); Tálas et al. (1998).

S2. Experimental

Naphthalene Tröger's base (100 mg, 0.311 mmol) was suspended in a mixture of trifluoroacetic anhydride (TFAA) (0.5 ml) and dichloromethane (1 ml) and stirred at room temperature in a closed vessel. The reaction was monitored by TLC. After 3 h all starting material had been consumed and the reaction was quenched with ice and basified with saturated sodium hydrogen carbonate solution. The cloudy mixture was extracted with dichloromethane (2 x 30 ml) and the organic layers were combined before being washed with brine, dried over anhydrous sodium sulfate and evaporated to dryness under reduced pressure, affording a colourless transparent solid. The residue (assumed to be the di-trifluoroacetylated disecondary amine) was dissolved in a mixture of ethanol (5 ml) and sodium hydroxide (100 mg) and stirred at room temperature for 12 h. Ethanol was removed under vacuum and the residue was taken up in a mixture of water (20 ml) and dichloromethane (20 ml). The organic layer was separated and the aqueous layer extracted with dichloromethane (20 ml). The combined organic layers were then washed with brine, dried over anhydrous sodium sulfate and evaporated to dryness under reduced pressure. The residue was chromatographed (silica gel, dichloromethane) to afford (I) (35 mg, 38%) as a white solid (the first major band eluted), m.p: 172.06 °C (DSC). Single crystals of (I) were grown by slow evaporation of a dichloromethane/methanol solution.

S3. Refinement

Refinement on F was by full-matrix least squares (RAELS) using anisotropic thermal parameters for non-hydrogen atoms. Hydrogen atoms were included in geometrically idealized positions calculated each cycle, with C—H distances of 1.00 Å, and were assigned thermal parameters equal to those of the parent atom. The NH protons were included in idealized positions after location in a difference fourier. The methanol was located in a difference fourier, and included as two independent anisotropic atoms. The H atoms were not located. This space group has a floating origin in the z direction, so to avoid a singular situation the z coordinate of one atom (N1) is fixed.

Computing details

Data collection: CAD-4 Software (Schagen et al., 1989); cell refinement: CAD-4 Software (Schagen et al., 1989); data reduction: local program; program(s) used to solve structure: SIR92 (Altomare et al., 1994); program(s) used to refine structure: RAELS (Rae, 1996); molecular graphics: ORTEPII (Johnson, 1976); software used to prepare material for publication: local programs.

Figures

	Fig. 1. ORTEPII (Johnson, 1976) plot of the title compound, with ellipsoids at the 10% probability level. H atoms are drawn as spheres of arbitrary radius. Symmetry code is: i 1/2 - x,1/2 - y,z.
	Fig. 2. The preparation of (I).

1,1'-Methylenebis(naphthalen-2-amine) methanol solvate

Crystal data

C21H18N2·CH4O	Dx = 1.28 Mg m^−3
Mr = 330.4	Melting point: 445 K
Orthorhombic, Ccc2	Mo Kα radiation, λ = 0.71073 Å
a = 13.020 (4) Å	Cell parameters from 11 reflections
b = 26.448 (7) Å	θ = 11–13°
c = 4.978 (2) Å	µ = 0.08 mm^−1
V = 1714.2 (9) Å^3	T = 294 K
Z = 4	Prism, colourless
F(000) = 704.0	0.30 × 0.12 × 0.10 mm

Data collection

Enraf–Nonius CAD-4 diffractometer	h = 0→15
ω–2θ scans	k = 0→31
851 measured reflections	l = 0→5
851 independent reflections	1 standard reflections every 30 min
720 reflections with I > 2σ(I)	intensity decay: none
θmax = 25°

Refinement

Refinement on F	H-atom parameters not refined
R[F^2 > 2σ(F^2)] = 0.049	w = 1/[σ^2(F) + 0.0004F^2]
wR(F^2) = 0.065	(Δ/σ)max = 0.002
S = 1.34	Δρmax = 0.26 e Å^−3
720 reflections	Δρmin = −0.23 e Å^−3
118 parameters

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

	x	y	z	Uiso*/Ueq	Occ. (<1)
N1	0.4225 (2)	0.2517 (1)	0.6709	0.0515 (7)
C1	0.3632 (2)	0.2076 (1)	0.6484 (8)	0.0462 (8)
C2	0.3936 (2)	0.1656 (1)	0.8030 (9)	0.0564 (9)
C3	0.3454 (3)	0.1203 (1)	0.7752 (10)	0.064 (1)
C4	0.2654 (2)	0.1137 (1)	0.5882 (10)	0.0574 (9)
C5	0.2174 (3)	0.0660 (1)	0.5540 (12)	0.072 (1)
C6	0.1411 (3)	0.0597 (2)	0.3746 (13)	0.080 (1)
C7	0.1081 (3)	0.1006 (2)	0.2175 (12)	0.073 (1)
C8	0.1523 (3)	0.1472 (1)	0.2473 (9)	0.062 (1)
C9	0.2335 (2)	0.1558 (1)	0.4327 (9)	0.0491 (8)
C10	0.2820 (2)	0.2038 (1)	0.4677 (8)	0.0441 (7)
C11	0.2500	0.2500	0.3067 (11)	0.051 (1)
C1Me	0.5000	0.0000	0.046 (6)	0.168 (7)
O1Me	0.4580 (6)	0.0183 (3)	0.296 (4)	0.216 (9)	0.5
H1N1	0.4835	0.2524	0.7930	0.052
H2N1	0.4038	0.2824	0.5648	0.052
HC2	0.4512	0.1691	0.9346	0.056
HC3	0.3671	0.0912	0.8898	0.064
HC5	0.2405	0.0366	0.6650	0.072
HC6	0.1079	0.0258	0.3534	0.080
HC7	0.0519	0.0957	0.0830	0.073
HC8	0.1269	0.1760	0.1354	0.062
H1C11	0.1906	0.2400	0.1907	0.051	0.5
H2C11	0.3094	0.2600	0.1907	0.051	0.5

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
N1	0.047 (1)	0.063 (2)	0.044 (2)	−0.003 (1)	−0.002 (1)	0.000 (1)
C1	0.042 (1)	0.060 (2)	0.038 (2)	0.006 (1)	0.005 (1)	−0.005 (2)
C2	0.054 (2)	0.068 (2)	0.047 (2)	0.006 (2)	−0.002 (2)	0.006 (2)
C3	0.065 (2)	0.066 (2)	0.062 (2)	0.012 (2)	0.000 (2)	0.012 (2)
C4	0.059 (2)	0.057 (2)	0.056 (2)	0.005 (2)	0.009 (2)	−0.001 (2)
C5	0.070 (2)	0.060 (2)	0.086 (3)	0.000 (2)	0.015 (3)	−0.002 (2)
C6	0.081 (3)	0.065 (2)	0.093 (3)	−0.013 (2)	0.021 (3)	−0.021 (3)
C7	0.072 (2)	0.084 (2)	0.065 (3)	−0.011 (2)	−0.002 (2)	−0.023 (2)
C8	0.063 (2)	0.077 (2)	0.047 (2)	−0.005 (2)	−0.004 (2)	−0.007 (2)
C9	0.047 (2)	0.061 (2)	0.039 (2)	0.001 (1)	0.008 (2)	−0.008 (2)
C10	0.047 (2)	0.053 (2)	0.032 (2)	0.005 (1)	0.005 (1)	−0.002 (2)
C11	0.058 (2)	0.063 (3)	0.032 (2)	−0.001 (2)	0.0000	0.0000
C1Me	0.141 (9)	0.096 (7)	0.267 (9)	0.009 (7)	0.0000	0.0000
O1Me	0.145 (9)	0.139 (9)	0.363 (9)	−0.001 (7)	−0.002 (9)	0.017 (9)

Geometric parameters (Å, º)

N1—C1	1.402 (4)	C6—C7	1.404 (7)
N1—H1N1	1.000	C6—HC6	1.000
N1—H2N1	1.000	C7—C8	1.368 (5)
C1—C2	1.408 (4)	C7—HC7	1.000
C1—C10	1.392 (4)	C8—C9	1.422 (4)
C2—C3	1.359 (5)	C8—HC8	1.000
C2—HC2	1.000	C9—C10	1.427 (4)
C3—C4	1.407 (5)	C10—C11	1.520 (4)
C3—HC3	1.000	C11—C10^i	1.520 (4)
C4—C5	1.418 (5)	C11—H1C11	1.000
C4—C9	1.420 (5)	C11—H2C11	1.000
C5—C6	1.346 (7)	C1Me—O1Me	1.443 (17)
C5—HC5	1.000
C1—N1—H1N1	120.0	C5—C6—HC6	120.1
C1—N1—H2N1	120.0	C7—C6—HC6	120.1
H1N1—N1—H2N1	120.0	C6—C7—C8	120.4 (4)
N1—C1—C2	117.3 (3)	C6—C7—HC7	119.8
N1—C1—C10	122.0 (3)	C8—C7—HC7	119.8
C2—C1—C10	120.6 (3)	C7—C8—C9	121.9 (4)
C1—C2—C3	120.7 (3)	C7—C8—HC8	119.1
C1—C2—HC2	119.7	C9—C8—HC8	119.1
C3—C2—HC2	119.7	C4—C9—C8	116.5 (3)
C2—C3—C4	121.2 (3)	C4—C9—C10	120.1 (3)
C2—C3—HC3	119.4	C8—C9—C10	123.4 (3)
C4—C3—HC3	119.4	C1—C10—C9	118.7 (3)
C3—C4—C5	121.1 (4)	C1—C10—C11	119.4 (2)
C3—C4—C9	118.7 (3)	C9—C10—C11	121.9 (3)
C5—C4—C9	120.2 (3)	C10—C11—C10^i	116.4 (4)
C4—C5—C6	121.1 (4)	C10—C11—H1C11	107.7
C4—C5—HC5	119.4	C10—C11—H2C11	107.7
C6—C5—HC5	119.4	H1C11—C11—H2C11	109.5
C5—C6—C7	119.9 (4)

Symmetry code: (i) −x+1/2, −y+1/2, z.