N-Phenyl-N-[(E)-2-(4,4,5,5-tetra­methyl-1,3,2-dioxaborolan-2-yl)ethen­yl]aniline

The title compound, C₂₀H₂₄BNO₂, has a polarized π-system due to significant resonance between the N—C(H)=C(H)—B and ionic N⁺=C(H)—C(H)=B⁻ canonical forms. The dihedral angles between the NC₂B plane (r.m.s. deviation 0.0223 Å) and the C₃N (r.m.s. deviation 0.0025 Å) and BCO₂ (r.m.s. deviation 0.0044 Å) planes are 2.51 (12) and 3.09 (19)°, respectively. This indicates the lone pair of the nitro­gen atom and a vacant p orbital of the boron atom are conjugated with the central C=C bond. In comparison with the carbazole analogue [Hatayama & Okuno (2012). Acta Cryst. E68, o84], the C—N and C—B bonds are shorter. The results are well explained by the increase in the contribution of the N⁺=C(H)—C(H)=B⁻ canonical form in the title compound.

Key indicators

• Single-crystal X-ray study
• T = 93 K
• Mean [sigma](C-C) = 0.003 Å
• R factor = 0.052
• wR factor = 0.147
• Data-to-parameter ratio = 17.8

checkCIF/PLATON results

No syntax errors found



Alert level C
PLAT906_ALERT_3_C Large K Value in the Analysis of Variance ......      3.129 Check
PLAT911_ALERT_3_C Missing FCF Refl Between Thmin & STh/L=    0.600         33 Report

Alert level G
PLAT013_ALERT_1_G N.O.K.   _shelx_hkl_checksum Found in CIF ......     Please Check
PLAT066_ALERT_1_G Predicted and Reported Tmin&Tmax Range Identical          ? Check
PLAT128_ALERT_4_G Alternate Setting for Input Space Group     C2/c       I2/a Note
PLAT395_ALERT_2_G Deviating  X-O-Y   Angle From 120 for O1       .      107.1 Degree
PLAT395_ALERT_2_G Deviating  X-O-Y   Angle From 120 for O2       .      107.0 Degree
PLAT912_ALERT_4_G Missing # of FCF Reflections Above STh/L=  0.600         45 Note
PLAT978_ALERT_2_G Number C-C Bonds with Positive Residual Density.          4 Info

   0 ALERT level A = Most likely a serious problem - resolve or explain
   0 ALERT level B = A potentially serious problem, consider carefully
   2 ALERT level C = Check. Ensure it is not caused by an omission or oversight
   7 ALERT level G = General information/check it is not something unexpected

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

---

Computing details

Data collection: CrystalClear (Rigaku, 2008); cell refinement: CrystalClear (Rigaku, 2008); data reduction: CrystalStructure (Rigaku, 2019); program(s) used to solve structure: SHELXS (Sheldrick, 2008); program(s) used to refine structure: SHELXL (Sheldrick, 2008); molecular graphics: ORTEP-3 for Windows (Farrugia, 2012); software used to prepare material for publication: publCIF (Westrip, 2010).

N-Phenyl-N-[(E)-2-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)ethenyl]aniline

Crystal data

C20H24BNO2	F(000) = 1376.00
Mr = 321.23	Dx = 1.182 Mg m^−3
Monoclinic, C2/c	Mo Kα radiation, λ = 0.71075 Å
a = 32.071 (11) Å	Cell parameters from 5341 reflections
b = 6.011 (2) Å	θ = 1.5–31.1°
c = 22.219 (8) Å	µ = 0.07 mm^−1
β = 122.590 (4)°	T = 93 K
V = 3609 (2) Å^3	Prism, colourless
Z = 8	0.13 × 0.11 × 0.05 mm

Data collection

Rigaku Saturn724+ diffractometer	3041 reflections with F^2 > 2.0σ(F^2)
Detector resolution: 7.111 pixels mm^-1	Rint = 0.084
ω scans	θmax = 27.0°, θmin = 1.5°
Absorption correction: numerical (NUMABS; Rigaku, 1999)	h = −33→40
Tmin = 0.991, Tmax = 0.996	k = −7→7
13892 measured reflections	l = −28→26
3869 independent reflections

Refinement

Refinement on F^2	Secondary atom site location: difference Fourier map
R[F^2 > 2σ(F^2)] = 0.052	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.147	H-atom parameters constrained
S = 1.09	w = 1/[σ^2(Fo^2) + (0.0758P)^2 + 0.8943P] where P = (Fo^2 + 2Fc^2)/3
3869 reflections	(Δ/σ)max < 0.001
217 parameters	Δρmax = 0.25 e Å^−3
0 restraints	Δρmin = −0.27 e Å^−3
Primary atom site location: structure-invariant direct methods

Special details

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

Refinement. Refinement was performed using all reflections. The weighted R-factor (wR) and goodness of fit (S) are based on F². R-factor (gt) are based on F. The threshold expression of F² > 2.0 sigma(F²) is used only for calculating R-factor (gt).

The C-bound H atoms were placed at ideal positions and were refined as riding on their parent C atoms. The U_iso(H) values were set at 1.2U_eq(C_sp2) and 1.5 U_eq(C_sp3).

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

	x	y	z	Uiso*/Ueq
O1	0.34742 (4)	0.98270 (18)	0.51068 (5)	0.0221 (3)
O2	0.41736 (4)	0.82168 (18)	0.60407 (5)	0.0218 (3)
N1	0.36028 (5)	0.6152 (2)	0.35305 (7)	0.0199 (3)
C1	0.32337 (5)	0.6584 (3)	0.28043 (8)	0.0190 (3)
C2	0.29881 (6)	0.8631 (3)	0.25973 (8)	0.0218 (3)
H2	0.3090	0.9801	0.2936	0.026*
C3	0.25961 (6)	0.8955 (3)	0.18984 (8)	0.0242 (4)
H3	0.2427	1.0342	0.1764	0.029*
C4	0.24475 (6)	0.7281 (3)	0.13936 (8)	0.0242 (4)
H4	0.2173	0.7497	0.0919	0.029*
C5	0.27059 (6)	0.5283 (3)	0.15912 (8)	0.0239 (4)
H5	0.2613	0.4146	0.1244	0.029*
C6	0.30963 (6)	0.4925 (3)	0.22861 (8)	0.0217 (3)
H6	0.3271	0.3555	0.2412	0.026*
C7	0.39973 (5)	0.4638 (2)	0.36945 (8)	0.0186 (3)
C8	0.40344 (6)	0.2606 (3)	0.40195 (8)	0.0220 (3)
H8	0.3798	0.2207	0.4133	0.026*
C9	0.44182 (6)	0.1166 (3)	0.41769 (8)	0.0237 (3)
H9	0.4446	−0.0221	0.4401	0.028*
C10	0.47629 (6)	0.1748 (3)	0.40080 (8)	0.0246 (4)
H10	0.5025	0.0757	0.4115	0.030*
C11	0.47247 (6)	0.3772 (3)	0.36832 (8)	0.0248 (4)
H11	0.4960	0.4166	0.3567	0.030*
C12	0.43426 (6)	0.5225 (3)	0.35273 (8)	0.0226 (3)
H12	0.4317	0.6617	0.3307	0.027*
C13	0.35865 (6)	0.7131 (2)	0.40803 (8)	0.0194 (3)
H13	0.3305	0.8029	0.3942	0.023*
C14	0.39193 (6)	0.6968 (3)	0.47847 (8)	0.0206 (3)
H14	0.4197	0.6011	0.4957	0.025*
C15	0.34973 (6)	1.0522 (3)	0.57530 (8)	0.0210 (3)
C16	0.40496 (6)	1.0063 (3)	0.63455 (8)	0.0226 (3)
C17	0.31353 (6)	0.9064 (3)	0.58176 (10)	0.0296 (4)
H17A	0.3140	0.9481	0.6247	0.036*
H17B	0.2801	0.9272	0.5396	0.036*
H17C	0.3232	0.7500	0.5851	0.036*
C18	0.33465 (6)	1.2945 (3)	0.56815 (9)	0.0261 (4)
H18A	0.3361	1.3421	0.6115	0.031*
H18B	0.3573	1.3857	0.5616	0.031*
H18C	0.3008	1.3124	0.5267	0.031*
C19	0.41396 (7)	0.9327 (3)	0.70589 (9)	0.0344 (4)
H19A	0.4058	1.0548	0.7270	0.041*
H19B	0.3931	0.8038	0.6988	0.041*
H19C	0.4488	0.8920	0.7380	0.041*
C20	0.43914 (6)	1.1987 (3)	0.64438 (10)	0.0311 (4)
H20A	0.4321	1.3267	0.6648	0.037*
H20B	0.4737	1.1530	0.6767	0.037*
H20C	0.4336	1.2400	0.5980	0.037*
B1	0.38529 (6)	0.8323 (3)	0.53116 (9)	0.0188 (4)

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
O1	0.0242 (6)	0.0246 (6)	0.0168 (6)	0.0045 (4)	0.0105 (5)	−0.0009 (4)
O2	0.0246 (6)	0.0227 (6)	0.0180 (6)	0.0047 (4)	0.0114 (5)	−0.0001 (4)
N1	0.0220 (7)	0.0207 (6)	0.0176 (6)	0.0024 (5)	0.0110 (6)	−0.0006 (5)
C1	0.0176 (7)	0.0236 (8)	0.0171 (7)	−0.0014 (6)	0.0101 (6)	0.0001 (6)
C2	0.0258 (8)	0.0213 (8)	0.0214 (8)	−0.0001 (6)	0.0149 (7)	−0.0009 (6)
C3	0.0248 (8)	0.0283 (8)	0.0242 (8)	0.0046 (6)	0.0164 (7)	0.0051 (6)
C4	0.0211 (8)	0.0338 (9)	0.0172 (8)	−0.0005 (6)	0.0101 (7)	0.0024 (6)
C5	0.0247 (8)	0.0298 (8)	0.0201 (8)	−0.0048 (6)	0.0139 (7)	−0.0042 (6)
C6	0.0239 (8)	0.0219 (8)	0.0233 (8)	0.0005 (6)	0.0154 (7)	−0.0004 (6)
C7	0.0178 (7)	0.0201 (7)	0.0159 (7)	0.0012 (6)	0.0077 (6)	−0.0024 (6)
C8	0.0215 (8)	0.0241 (8)	0.0224 (8)	−0.0025 (6)	0.0132 (7)	−0.0023 (6)
C9	0.0256 (8)	0.0209 (8)	0.0231 (8)	0.0005 (6)	0.0121 (7)	−0.0002 (6)
C10	0.0215 (8)	0.0267 (8)	0.0226 (8)	0.0024 (6)	0.0099 (7)	−0.0038 (6)
C11	0.0216 (8)	0.0312 (9)	0.0244 (8)	−0.0018 (6)	0.0143 (7)	−0.0035 (7)
C12	0.0253 (8)	0.0236 (8)	0.0206 (8)	−0.0007 (6)	0.0135 (7)	−0.0002 (6)
C13	0.0210 (8)	0.0183 (7)	0.0241 (8)	−0.0015 (6)	0.0155 (7)	−0.0021 (6)
C14	0.0202 (8)	0.0212 (7)	0.0216 (8)	0.0012 (6)	0.0121 (7)	−0.0011 (6)
C15	0.0252 (8)	0.0207 (7)	0.0203 (8)	0.0021 (6)	0.0143 (7)	−0.0009 (6)
C16	0.0272 (8)	0.0227 (8)	0.0195 (8)	0.0014 (6)	0.0136 (7)	−0.0011 (6)
C17	0.0329 (9)	0.0244 (8)	0.0404 (10)	−0.0022 (7)	0.0256 (8)	−0.0032 (7)
C18	0.0313 (9)	0.0214 (8)	0.0286 (9)	0.0041 (6)	0.0182 (8)	0.0009 (6)
C19	0.0430 (10)	0.0406 (10)	0.0193 (8)	0.0060 (8)	0.0166 (8)	0.0008 (7)
C20	0.0280 (9)	0.0308 (9)	0.0300 (9)	−0.0045 (7)	0.0127 (8)	−0.0091 (7)
B1	0.0193 (8)	0.0187 (8)	0.0203 (9)	−0.0020 (6)	0.0118 (7)	−0.0007 (6)

Geometric parameters (Å, º)

O1—B1	1.380 (2)	C10—H10	0.9500
O1—C15	1.4585 (18)	C11—C12	1.388 (2)
O2—B1	1.375 (2)	C11—H11	0.9500
O2—C16	1.4623 (18)	C12—H12	0.9500
N1—C13	1.3824 (19)	C13—C14	1.341 (2)
N1—C1	1.419 (2)	C13—H13	0.9500
N1—C7	1.4369 (19)	C14—B1	1.532 (2)
C1—C2	1.398 (2)	C14—H14	0.9500
C1—C6	1.403 (2)	C15—C18	1.516 (2)
C2—C3	1.388 (2)	C15—C17	1.522 (2)
C2—H2	0.9500	C15—C16	1.560 (2)
C3—C4	1.386 (2)	C16—C19	1.516 (2)
C3—H3	0.9500	C16—C20	1.526 (2)
C4—C5	1.390 (2)	C17—H17A	0.9800
C4—H4	0.9500	C17—H17B	0.9800
C5—C6	1.384 (2)	C17—H17C	0.9800
C5—H5	0.9500	C18—H18A	0.9800
C6—H6	0.9500	C18—H18B	0.9800
C7—C12	1.390 (2)	C18—H18C	0.9800
C7—C8	1.391 (2)	C19—H19A	0.9800
C8—C9	1.387 (2)	C19—H19B	0.9800
C8—H8	0.9500	C19—H19C	0.9800
C9—C10	1.390 (2)	C20—H20A	0.9800
C9—H9	0.9500	C20—H20B	0.9800
C10—C11	1.386 (2)	C20—H20C	0.9800
B1—O1—C15	107.10 (11)	N1—C13—H13	116.0
B1—O2—C16	107.02 (12)	C13—C14—B1	120.13 (14)
C13—N1—C1	121.41 (13)	C13—C14—H14	119.9
C13—N1—C7	119.53 (13)	B1—C14—H14	119.9
C1—N1—C7	119.05 (12)	O1—C15—C18	109.14 (12)
C2—C1—C6	118.90 (14)	O1—C15—C17	106.93 (13)
C2—C1—N1	120.80 (14)	C18—C15—C17	110.29 (13)
C6—C1—N1	120.25 (14)	O1—C15—C16	102.26 (12)
C3—C2—C1	120.12 (15)	C18—C15—C16	114.30 (13)
C3—C2—H2	119.9	C17—C15—C16	113.29 (13)
C1—C2—H2	119.9	O2—C16—C19	108.47 (13)
C4—C3—C2	120.84 (15)	O2—C16—C20	106.72 (13)
C4—C3—H3	119.6	C19—C16—C20	110.72 (14)
C2—C3—H3	119.6	O2—C16—C15	102.24 (12)
C3—C4—C5	119.03 (15)	C19—C16—C15	115.10 (14)
C3—C4—H4	120.5	C20—C16—C15	112.83 (13)
C5—C4—H4	120.5	C15—C17—H17A	109.5
C6—C5—C4	120.93 (15)	C15—C17—H17B	109.5
C6—C5—H5	119.5	H17A—C17—H17B	109.5
C4—C5—H5	119.5	C15—C17—H17C	109.5
C5—C6—C1	120.06 (15)	H17A—C17—H17C	109.5
C5—C6—H6	120.0	H17B—C17—H17C	109.5
C1—C6—H6	120.0	C15—C18—H18A	109.5
C12—C7—C8	120.28 (14)	C15—C18—H18B	109.5
C12—C7—N1	119.38 (14)	H18A—C18—H18B	109.5
C8—C7—N1	120.34 (13)	C15—C18—H18C	109.5
C9—C8—C7	119.68 (14)	H18A—C18—H18C	109.5
C9—C8—H8	120.2	H18B—C18—H18C	109.5
C7—C8—H8	120.2	C16—C19—H19A	109.5
C8—C9—C10	120.11 (15)	C16—C19—H19B	109.5
C8—C9—H9	119.9	H19A—C19—H19B	109.5
C10—C9—H9	119.9	C16—C19—H19C	109.5
C11—C10—C9	120.09 (15)	H19A—C19—H19C	109.5
C11—C10—H10	120.0	H19B—C19—H19C	109.5
C9—C10—H10	120.0	C16—C20—H20A	109.5
C10—C11—C12	120.06 (15)	C16—C20—H20B	109.5
C10—C11—H11	120.0	H20A—C20—H20B	109.5
C12—C11—H11	120.0	C16—C20—H20C	109.5
C11—C12—C7	119.77 (15)	H20A—C20—H20C	109.5
C11—C12—H12	120.1	H20B—C20—H20C	109.5
C7—C12—H12	120.1	O2—B1—O1	112.71 (13)
C14—C13—N1	127.95 (14)	O2—B1—C14	123.48 (14)
C14—C13—H13	116.0	O1—B1—C14	123.79 (14)
C13—N1—C1—C2	30.2 (2)	C1—N1—C13—C14	−176.36 (15)
C7—N1—C1—C2	−150.72 (14)	C7—N1—C13—C14	4.5 (2)
C13—N1—C1—C6	−147.37 (14)	N1—C13—C14—B1	175.57 (14)
C7—N1—C1—C6	31.7 (2)	B1—O1—C15—C18	145.27 (13)
C6—C1—C2—C3	3.7 (2)	B1—O1—C15—C17	−95.43 (14)
N1—C1—C2—C3	−173.86 (13)	B1—O1—C15—C16	23.86 (15)
C1—C2—C3—C4	−1.1 (2)	B1—O2—C16—C19	146.11 (14)
C2—C3—C4—C5	−1.8 (2)	B1—O2—C16—C20	−94.56 (14)
C3—C4—C5—C6	2.1 (2)	B1—O2—C16—C15	24.11 (14)
C4—C5—C6—C1	0.6 (2)	O1—C15—C16—O2	−28.89 (14)
C2—C1—C6—C5	−3.4 (2)	C18—C15—C16—O2	−146.69 (13)
N1—C1—C6—C5	174.15 (13)	C17—C15—C16—O2	85.81 (15)
C13—N1—C7—C12	−113.40 (16)	O1—C15—C16—C19	−146.25 (14)
C1—N1—C7—C12	67.48 (19)	C18—C15—C16—C19	95.96 (17)
C13—N1—C7—C8	66.41 (19)	C17—C15—C16—C19	−31.54 (19)
C1—N1—C7—C8	−112.71 (16)	O1—C15—C16—C20	85.36 (15)
C12—C7—C8—C9	0.0 (2)	C18—C15—C16—C20	−32.44 (18)
N1—C7—C8—C9	−179.76 (14)	C17—C15—C16—C20	−159.93 (13)
C7—C8—C9—C10	−0.2 (2)	C16—O2—B1—O1	−10.22 (17)
C8—C9—C10—C11	0.2 (2)	C16—O2—B1—C14	168.01 (14)
C9—C10—C11—C12	0.1 (2)	C15—O1—B1—O2	−9.76 (17)
C10—C11—C12—C7	−0.3 (2)	C15—O1—B1—C14	172.01 (14)
C8—C7—C12—C11	0.3 (2)	C13—C14—B1—O2	178.88 (14)
N1—C7—C12—C11	−179.94 (13)	C13—C14—B1—O1	−3.1 (2)