N6-Benzyl­adenine hydro­bromide and the solid-state conformation of cytokinins

Umadevi, B.; Stanley, N.; Muthiah, P.T.; Bocelli, G.; Cantoni, A.

doi:10.1107/S1600536801013629

N⁶-Benzyladenine hydrobromide and the solid-state conformation of cytokinins

B. Umadevi, N. Stanley, P. T. Muthiah, G. Bocelli and A. Cantoni

In the title compound, N⁶-benzyladenine hydrobromide [N⁶-benzyladeninium bromide], C₁₂H₁₂N₅⁺·Br^-, the adenine moiety exists as the N3-protonated N7-H tautomer. The N6 substituent is distal to N7 and the phenyl ring makes a dihedral angle of 108.43 (12)° with the adenine plane. Thus, protonation of benzyladenine does not affect the conformational requirements for cytokinin activity. The conformation of the title compound has been compared with other cytokinins.

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Supporting information

	Crystallographic Information File (CIF) https://doi.org/10.1107/S1600536801013629/cv6033sup1.cif Contains datablocks global, I
	Structure factor file (CIF format) https://doi.org/10.1107/S1600536801013629/cv6033Isup2.hkl Contains datablock I

CCDC reference: 172220

checkCIF report

Key indicators

Single-crystal X-ray study
T = 293 K
Mean (C-C) = 0.014 Å
R factor = 0.067
wR factor = 0.173
Data-to-parameter ratio = 7.5

checkCIF results

No syntax errors found

ADDSYM reports no extra symmetry


 Alert Level A:



REFLT_03
         From the CIF: _diffrn_reflns_theta_max           69.90
         From the CIF: _reflns_number_total               1556
         TEST2: Reflns within _diffrn_reflns_theta_max
         Count of symmetry unique reflns         2428
         Completeness (_total/calc)             64.09%
          Alert A: < 85% complete (theta max?)


 Alert Level C:



RINTA_01  Alert C The value of Rint is greater than 0.10
          Rint given   0.106

General Notes



ABSTM_02  When printed, the submitted absorption T values will be replaced
          by the scaled T values. Since the ratio of scaled T's is
          identical to the ratio of reported T values, the scaling does
          not imply a change to the absorption corrections used in the
          study.
          Ratio of Tmax expected/reported      1.075
          Tmax scaled      0.524 Tmin scaled      0.352


 1 Alert Level A = Potentially serious problem

 0 Alert Level B = Potential problem

 1 Alert Level C = Please check

Comment top

Many N6-substituted adenine derivatives function as plant growth stimulants (Hall, 1973). Kinetin (N⁶-furfurylaminopurine) is one of the naturally occurring cytokinins. Some of the N6-substituted adenines synthesized also show cytokinin activity depending upon their conformation (Pattabhi, 1990). N⁶-Benzyladenine hydrobromide (BABR), (I), has been investigated to explore the conformation of this molecule in a variety of crystalline and chemical environments. The ZORTEP diagram (Zsolnai, 1997) of the molecule with the atom-labeling scheme is shown in Fig. 1.

N⁶-Benzyladenine exists as the N9—H tautomer in the crystal structure (Ragunathan et al., 1983). In monoprotonated adenine systems, N1 is the protonation site (Voet & Rich, 1970). However, in this crystal structure, very interestingly, adenine moiety exists as the N7—H tautomer with the proton at N3. The H atoms at N7 and N3 were located in the difference Fourier map. Further evidence for the presence of the H atoms on these sites comes from the enhancement of the corresponding internal bond angles. The enhancement of the internal bond angles on protonation sites has been already well established (Taylor & Kennard, 1982). In the crystal structure of a copper complex of benzyladenine (Balasubramanian et al., 1996) also, which was prepared under slightly acidic conditions, the adenine moieties exist as the N7—H tautomer with protonation at N3 and coordination at N9. In BABR, the internal angle at N9 is 103.2 (7)°, which agrees well with that observed in N⁶-benzyladenine existing as N7—H tautomer. In the crystal structure of N⁶-benzoyladenine (Ragunathan & Pattabhi, 1981), the adeinine moiety exists as the N7—H tautomer rather than the normal N9—H tautomer for neutral adenines and this is due to intramolecular hydrogen bonding. It has been suggested that a free N1 position is one of the requirements for cytokinin activity and it is interesting to note that the N1 position is maintained free even under acidic conditions/metal binding namely in BABR and a copper complex of N⁶-benzyladenine. [Please clarify this wording]

There is no significant base stacking. This is in agreement with the packing patterns of other cytokinins previously reported. The molecules are packed by N—H···N and N—H···Br interactions.

The dihedral angle between the adenine plane and the phenyl-ring plane is 108.43 (12)°. This is in agreement with the range of values nearly 90° proposed for cytokinin activity. The N6 substituent is also distal to N7 as in other cytokinins (Sariano-Garcia & Parthasarathi, 1977; Ragunathan & Pattabhi, 1981; Bugg & Thewalt, 1972; McMullan & Sundaralingam, 1971; Walker & Tollin, 1982). Thus, a free N1, distal conformation of the N6 substituent with respect to N7, absence of base stacking and a near 90° value of the dihedral angle (between the adenine ring and the plane of the N6-substituent) seem to be necessary conditions for cytokinin activity.

Experimental top

N⁶-Benzyladenine (Loba Chemie, India) was dissolved in the minimum amount of dilute hydrobromic acid and recrystalliz ed from a methanol/n-pentane mixture.

Computing details top

Data collection: DIFABS (Walker & Stuart, 1983); cell refinement: DIFABS (Walker & Stuart, 1983); data reduction: DIFABS (Walker & Stuart, 1983); program(s) used to solve structure: SHELXS97 (sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: ZORTEP97 (Zsolnai, 1997); software used to prepare material for publication: PLATON (Spek, 1990).

Figures top

Fig. 1. ZORTEP diagram (Zsolnai, 1997) of the title compound showing 50% probability displacement ellipsoids.

(I) top

Crystal data top

C₁₂H₁₂BrN₅	F(000) = 616
M_r = 306.16	D_x = 1.592 Mg m⁻³
Monoclinic, P2₁/c	Cu Kα radiation, λ = 1.54178 Å
a = 18.581 (3) Å	Cell parameters from 40 reflections
b = 5.163 (2) Å	θ = 6.8–16.3°
c = 13.344 (3) Å	µ = 4.31 mm⁻¹
β = 93.71 (2)°	T = 293 K
V = 1277.5 (6) Å³	Needle, colourless
Z = 4	0.33 × 0.18 × 0.15 mm

Data collection top

Siemens AED diffractometer	R_int = 0.106
ω–2θ scans	θ_max = 69.9°, θ_min = 4.8°
Absorption correction: part of the refinement model (ΔF) (Parkin et al., 1995)	h = −22→22
T_min = 0.327, T_max = 0.488	k = 0→6
1608 measured reflections	l = −16→15
1556 independent reflections	3 standard reflections every 60 min
1556 reflections with I > 2σ(I)	intensity decay: none

Refinement top

Refinement on F²	Secondary atom site location: difference Fourier map
Least-squares matrix: full	Hydrogen site location: inferred from neighbouring sites
R[F² > 2σ(F²)] = 0.067	H atoms treated by a mixture of independent and constrained refinement
wR(F²) = 0.173	w = 1/[σ²(F_o²) + (0.0956P)² + 1.1524P] where P = (F_o² + 2F_c²)/3
S = 1.04	(Δ/σ)_max < 0.001
1556 reflections	Δρ_max = 0.94 e Å⁻³
208 parameters	Δρ_min = −1.44 e Å⁻³
0 restraints	Extinction correction: SHELXL97
Primary atom site location: structure-invariant direct methods	Extinction coefficient: 0.0025 (5)

Crystal data top

C₁₂H₁₂BrN₅	V = 1277.5 (6) Å³
M_r = 306.16	Z = 4
Monoclinic, P2₁/c	Cu Kα radiation
a = 18.581 (3) Å	µ = 4.31 mm⁻¹
b = 5.163 (2) Å	T = 293 K
c = 13.344 (3) Å	0.33 × 0.18 × 0.15 mm
β = 93.71 (2)°

Data collection top

Siemens AED diffractometer	1556 reflections with I > 2σ(I)
Absorption correction: part of the refinement model (ΔF) (Parkin et al., 1995)	R_int = 0.106
T_min = 0.327, T_max = 0.488	3 standard reflections every 60 min
1608 measured reflections	intensity decay: none
1556 independent reflections

Refinement top

R[F² > 2σ(F²)] = 0.067	0 restraints
wR(F²) = 0.173	H atoms treated by a mixture of independent and constrained refinement
S = 1.04	Δρ_max = 0.94 e Å⁻³
1556 reflections	Δρ_min = −1.44 e Å⁻³
208 parameters

Special details top

Geometry. Bond distances, angles etc. have been calculated using the rounded fractional coordinates. All e.s.d.'s are estimated from the variances of the (full) variance-covariance matrix. The cell e.s.d.'s are taken into account in the estimation of distances, angles and torsion angles

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å²) top

	x	y	z	U_iso*/U_eq
Br1	0.16929 (4)	0.53176 (16)	0.30710 (5)	0.0596 (3)
N1	0.2273 (3)	0.2989 (12)	0.0426 (4)	0.057 (2)
N3	0.1098 (4)	0.4556 (12)	0.0018 (4)	0.0560 (19)
N6	0.2478 (4)	−0.0404 (15)	0.1532 (5)	0.0603 (19)
N7	0.0819 (3)	−0.0472 (14)	0.1658 (4)	0.055 (2)
N9	0.0124 (4)	0.2408 (13)	0.0828 (4)	0.061 (2)
C2	0.1815 (5)	0.4583 (16)	−0.0052 (5)	0.061 (2)
C4	0.0817 (4)	0.2757 (14)	0.0612 (5)	0.053 (2)
C5	0.1274 (4)	0.0999 (13)	0.1106 (5)	0.049 (2)
C6	0.2020 (4)	0.1146 (14)	0.1031 (5)	0.051 (2)
C8	0.0158 (4)	0.0417 (17)	0.1466 (5)	0.059 (3)
C10	0.3251 (5)	−0.033 (3)	0.1476 (8)	0.087 (4)
C11	0.3635 (4)	−0.0937 (18)	0.2487 (6)	0.062 (3)
C12	0.3496 (6)	0.039 (2)	0.3326 (8)	0.081 (3)
C13	0.3846 (6)	−0.021 (2)	0.4229 (8)	0.090 (4)
C14	0.4354 (6)	−0.207 (3)	0.4295 (8)	0.100 (5)
C15	0.4499 (6)	−0.347 (3)	0.3451 (9)	0.096 (5)
C16	0.4131 (5)	−0.289 (2)	0.2542 (7)	0.071 (3)
H2	0.200 (4)	0.601 (17)	−0.047 (6)	0.06 (2)*
H3	0.084 (4)	0.567 (13)	−0.032 (5)	0.040 (18)*
H6	0.234 (3)	−0.178 (14)	0.182 (5)	0.042 (18)*
H7	0.094 (3)	−0.167 (13)	0.197 (5)	0.031 (17)*
H8	−0.024 (5)	−0.024 (15)	0.171 (7)	0.07 (3)*
H10A	0.333 (8)	−0.18 (3)	0.090 (11)	0.17 (6)*
H10B	0.335 (5)	0.125 (18)	0.135 (7)	0.06 (3)*
H12	0.314 (4)	0.178 (17)	0.328 (6)	0.07 (2)*
H13	0.37318	0.06793	0.48036	0.1078*
H14	0.455 (8)	−0.27 (3)	0.474 (11)	0.17 (7)*
H15	0.486 (6)	−0.47 (2)	0.345 (8)	0.10 (4)*
H16	0.420 (6)	−0.40 (3)	0.203 (9)	0.11 (4)*

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
Br1	0.0661 (6)	0.0654 (6)	0.0464 (5)	0.0064 (4)	−0.0025 (3)	0.0038 (3)
N1	0.067 (4)	0.063 (4)	0.041 (3)	−0.004 (3)	−0.003 (3)	0.004 (3)
N3	0.070 (4)	0.051 (3)	0.045 (3)	0.004 (3)	−0.012 (3)	0.007 (3)
N6	0.054 (3)	0.075 (4)	0.051 (3)	0.003 (3)	−0.004 (3)	0.020 (3)
N7	0.059 (4)	0.056 (4)	0.049 (3)	0.007 (3)	−0.009 (3)	0.007 (3)
N9	0.062 (4)	0.069 (4)	0.052 (3)	0.012 (3)	−0.006 (3)	0.002 (3)
C2	0.078 (5)	0.062 (4)	0.042 (3)	−0.003 (4)	−0.006 (3)	0.003 (3)
C4	0.062 (4)	0.052 (4)	0.044 (3)	0.001 (3)	−0.011 (3)	−0.006 (3)
C5	0.061 (4)	0.047 (4)	0.038 (3)	−0.003 (3)	−0.002 (3)	0.000 (3)
C6	0.061 (4)	0.052 (4)	0.038 (3)	0.002 (3)	−0.006 (3)	0.000 (3)
C8	0.050 (4)	0.076 (5)	0.050 (4)	0.006 (4)	−0.002 (3)	0.002 (3)
C10	0.058 (5)	0.132 (11)	0.071 (6)	0.015 (6)	0.006 (4)	0.039 (7)
C11	0.047 (4)	0.078 (5)	0.062 (4)	−0.002 (4)	0.001 (3)	0.020 (4)
C12	0.072 (5)	0.088 (7)	0.082 (6)	0.024 (5)	0.003 (4)	0.002 (5)
C13	0.091 (7)	0.109 (8)	0.068 (5)	0.018 (6)	−0.005 (5)	−0.017 (5)
C14	0.072 (6)	0.161 (13)	0.064 (6)	0.008 (7)	−0.008 (5)	0.028 (7)
C15	0.071 (6)	0.129 (10)	0.086 (7)	0.038 (7)	−0.002 (5)	0.032 (7)
C16	0.069 (5)	0.085 (6)	0.059 (5)	0.014 (5)	0.009 (4)	0.006 (4)

Geometric parameters (Å, º) top

N1—C2	1.318 (10)	C11—C16	1.365 (13)
N1—C6	1.352 (9)	C11—C12	1.352 (13)
N3—C2	1.342 (12)	C12—C13	1.367 (15)
N3—C4	1.348 (9)	C13—C14	1.345 (17)
N6—C6	1.318 (10)	C14—C15	1.379 (18)
N6—C10	1.444 (12)	C15—C16	1.386 (15)
N7—C5	1.384 (9)	C2—H2	1.00 (8)
N7—C8	1.321 (10)	C8—H8	0.89 (9)
N9—C4	1.350 (10)	C10—H10A	1.10 (15)
N9—C8	1.334 (10)	C10—H10B	0.86 (9)
N3—H3	0.86 (7)	C12—H12	0.98 (8)
N6—H6	0.85 (7)	C13—H13	0.9299
N7—H7	0.77 (7)	C14—H14	0.75 (15)
C4—C5	1.381 (10)	C15—H15	0.92 (11)
C5—C6	1.398 (11)	C16—H16	0.91 (13)
C10—C11	1.517 (13)

Br1···N6ⁱ	3.408 (7)	C5···Br1	3.491 (7)
Br1···N7ⁱ	3.244 (6)	C6···Br1	3.554 (7)
Br1···C5	3.491 (7)	C8···Br1^x	3.534 (8)
Br1···C6	3.554 (7)	C8···N9^vii	3.401 (9)
Br1···C8ⁱⁱ	3.534 (8)	C8···H3^v	3.08 (7)
Br1···C2ⁱⁱⁱ	3.557 (8)	C12···H6	3.06 (6)
Br1···C2^iv	3.631 (8)	C13···H10A^xi	2.92 (15)
Br1···H7ⁱ	2.50 (6)	C14···H10A^xi	3.01 (15)
Br1···H8ⁱⁱ	2.75 (9)	C16···H15^xii	2.88 (11)
Br1···H12	3.25 (8)	H2···Br1^ix	2.75 (8)
Br1···H6ⁱ	2.60 (7)	H3···N9^v	2.12 (7)
Br1···H2^iv	2.75 (8)	H3···C8^v	3.08 (7)
N3···N9^v	2.925 (10)	H6···Br1^vi	2.60 (7)
N6···N7	3.098 (9)	H6···N7	2.90 (6)
N6···Br1^vi	3.408 (7)	H6···C12	3.06 (6)
N7···N6	3.098 (9)	H7···Br1^vi	2.50 (6)
N7···Br1^vi	3.244 (6)	H8···Br1^x	2.75 (9)
N9···C8^vii	3.401 (9)	H10A···H16	2.42 (19)
N9···N3^v	2.925 (10)	H10A···C13^xiii	2.92 (15)
N1···H10B	2.45 (9)	H10A···C14^xiii	3.01 (15)
N6···H12	2.80 (8)	H10B···N1	2.45 (9)
N7···H6	2.90 (6)	H12···Br1	3.25 (8)
N9···H3^v	2.12 (7)	H12···N6	2.80 (8)
C2···Br1^viii	3.557 (8)	H15···C16^xiv	2.88 (11)
C2···Br1^ix	3.631 (8)	H16···H10A	2.42 (19)

C2—N1—C6	119.3 (6)	C12—C11—C16	119.6 (8)
C2—N3—C4	118.2 (7)	C11—C12—C13	120.6 (10)
C6—N6—C10	124.7 (8)	C12—C13—C14	120.7 (10)
C5—N7—C8	107.4 (6)	C13—C14—C15	119.6 (11)
C4—N9—C8	103.5 (6)	C14—C15—C16	119.3 (12)
C4—N3—H3	123 (5)	C11—C16—C15	120.0 (10)
C2—N3—H3	119 (5)	N1—C2—H2	120 (4)
C10—N6—H6	112 (4)	N3—C2—H2	115 (4)
C6—N6—H6	122 (4)	N7—C8—H8	125 (6)
C5—N7—H7	124 (4)	N9—C8—H8	121 (6)
C8—N7—H7	128 (4)	N6—C10—H10A	101 (8)
N1—C2—N3	124.9 (7)	N6—C10—H10B	105 (6)
N9—C4—C5	112.1 (6)	C11—C10—H10A	114 (8)
N3—C4—N9	129.0 (7)	C11—C10—H10B	106 (6)
N3—C4—C5	118.9 (7)	H10A—C10—H10B	119 (11)
N7—C5—C4	103.7 (6)	C11—C12—H12	119 (5)
C4—C5—C6	120.8 (6)	C13—C12—H12	120 (5)
N7—C5—C6	135.3 (6)	C12—C13—H13	119.60
N1—C6—N6	119.5 (7)	C14—C13—H13	119.67
N6—C6—C5	122.8 (7)	C13—C14—H14	132 (11)
N1—C6—C5	117.8 (6)	C15—C14—H14	108 (11)
N7—C8—N9	113.4 (7)	C14—C15—H15	123 (7)
N6—C10—C11	111.1 (8)	C16—C15—H15	118 (7)
C10—C11—C12	121.8 (9)	C11—C16—H16	124 (8)
C10—C11—C16	118.5 (9)	C15—C16—H16	116 (9)

C6—N1—C2—N3	0.7 (11)	N9—C4—C5—C6	−175.9 (6)
C2—N1—C6—N6	−178.1 (7)	N9—C4—C5—N7	−0.5 (8)
C2—N1—C6—C5	1.0 (10)	C4—C5—C6—N6	176.3 (7)
C4—N3—C2—N1	−0.7 (11)	C4—C5—C6—N1	−2.8 (10)
C2—N3—C4—N9	177.4 (7)	N7—C5—C6—N1	−176.4 (7)
C2—N3—C4—C5	−1.2 (10)	N7—C5—C6—N6	2.7 (13)
C10—N6—C6—N1	−1.1 (12)	N6—C10—C11—C16	125.5 (10)
C10—N6—C6—C5	179.8 (9)	N6—C10—C11—C12	−54.2 (15)
C6—N6—C10—C11	144.2 (9)	C10—C11—C12—C13	179.5 (10)
C8—N7—C5—C4	0.6 (8)	C16—C11—C12—C13	−0.2 (15)
C8—N7—C5—C6	174.9 (8)	C10—C11—C16—C15	179.1 (10)
C5—N7—C8—N9	−0.5 (9)	C12—C11—C16—C15	−1.2 (15)
C8—N9—C4—N3	−178.4 (7)	C11—C12—C13—C14	2.4 (17)
C8—N9—C4—C5	0.3 (8)	C12—C13—C14—C15	−3.1 (19)
C4—N9—C8—N7	0.2 (8)	C13—C14—C15—C16	1.6 (19)
N3—C4—C5—N7	178.3 (6)	C14—C15—C16—C11	0.5 (17)
N3—C4—C5—C6	2.9 (10)

Symmetry codes: (i) x, y+1, z; (ii) −x, y+1/2, −z+1/2; (iii) x, −y+1/2, z+1/2; (iv) x, −y+3/2, z+1/2; (v) −x, −y+1, −z; (vi) x, y−1, z; (vii) −x, −y, −z; (viii) x, −y+1/2, z−1/2; (ix) x, −y+3/2, z−1/2; (x) −x, y−1/2, −z+1/2; (xi) x, −y−1/2, z+1/2; (xii) −x+1, y+1/2, −z+1/2; (xiii) x, −y−1/2, z−1/2; (xiv) −x+1, y−1/2, −z+1/2.

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
N3—H3···N9^v	0.86 (7)	2.12 (7)	2.925 (10)	156 (7)
N6—H6···Br1^vi	0.85 (7)	2.60 (7)	3.408 (7)	159 (6)
N7—H7···Br1^vi	0.77 (7)	2.50 (6)	3.244 (6)	161 (5)
C2—H2···Br1^ix	1.00 (8)	2.75 (8)	3.631 (8)	147 (6)
C8—H8···Br1^x	0.89 (9)	2.75 (9)	3.534 (8)	147 (7)
C10—H10B···N1	0.86 (9)	2.45 (9)	2.806 (14)	106 (7)

Symmetry codes: (v) −x, −y+1, −z; (vi) x, y−1, z; (ix) x, −y+3/2, z−1/2; (x) −x, y−1/2, −z+1/2.

Experimental details

Crystal data
Chemical formula	C₁₂H₁₂BrN₅
M_r	306.16
Crystal system, space group	Monoclinic, P2₁/c
Temperature (K)	293
a, b, c (Å)	18.581 (3), 5.163 (2), 13.344 (3)
β (°)	93.71 (2)
V (Å³)	1277.5 (6)
Z	4
Radiation type	Cu Kα
µ (mm⁻¹)	4.31
Crystal size (mm)	0.33 × 0.18 × 0.15

Data collection
Diffractometer	Siemens AED diffractometer
Absorption correction	Part of the refinement model (ΔF) (Parkin et al., 1995)
T_min, T_max	0.327, 0.488
No. of measured, independent and observed [I > 2σ(I)] reflections	1608, 1556, 1556
R_int	0.106
(sin θ/λ)_max (Å⁻¹)	0.609

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.067, 0.173, 1.04
No. of reflections	1556
No. of parameters	208
H-atom treatment	H atoms treated by a mixture of independent and constrained refinement
Δρ_max, Δρ_min (e Å⁻³)	0.94, −1.44

Computer programs: DIFABS (Walker & Stuart, 1983), SHELXS97 (sheldrick, 1997), SHELXL97 (Sheldrick, 1997), ZORTEP97 (Zsolnai, 1997), PLATON (Spek, 1990).

Selected geometric parameters (Å, º) top

N1—C2	1.318 (10)	N6—C10	1.444 (12)
N1—C6	1.352 (9)	N7—C5	1.384 (9)
N3—C2	1.342 (12)	N7—C8	1.321 (10)
N3—C4	1.348 (9)	N9—C4	1.350 (10)
N6—C6	1.318 (10)	N9—C8	1.334 (10)

C2—N1—C6	119.3 (6)	N3—C4—C5	118.9 (7)
C2—N3—C4	118.2 (7)	N7—C5—C4	103.7 (6)
C6—N6—C10	124.7 (8)	N7—C5—C6	135.3 (6)
C5—N7—C8	107.4 (6)	N1—C6—N6	119.5 (7)
C4—N9—C8	103.5 (6)	N6—C6—C5	122.8 (7)
N1—C2—N3	124.9 (7)	N1—C6—C5	117.8 (6)
N9—C4—C5	112.1 (6)	N7—C8—N9	113.4 (7)
N3—C4—N9	129.0 (7)	N6—C10—C11	111.1 (8)