1-Benzyl-4-(4-tert-butyl­phen­yl)piperazine

In the title compound, C₂₁H₂₈N₂, the two benzene rings are oriented nearly perpendicular to each other, and the piperazine ring adopts a chair conformation.

Key indicators

• Single-crystal X-ray study
• T = 291 K
• Mean [sigma](C-C)= 0.004 Å
• R factor = 0.057
• wR factor = 0.163
• Data-to-parameter ratio = 17.1

checkCIF/PLATON results

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Computing details

Data collection: SMART (Bruker, 2000); cell refinement: SAINT-Plus (Bruker, 2000); data reduction: SAINT-Plus; program(s) used to solve structure: SHELXTL (Bruker, 2000); program(s) used to refine structure: SHELXTL; molecular graphics: SHELXTL; software used to prepare material for publication: SHELXTL.

1-Benzyl-4-(4-tert-butylphenyl)piperazine

Crystal data

C21H28N2	F(000) = 672
Mr = 308.45	Dx = 1.123 Mg m^−3
Monoclinic, P21/c	Melting point: 348 K
Hall symbol: -P 2ybc	Mo Kα radiation, λ = 0.71073 Å
a = 6.2461 (11) Å	Cell parameters from 1891 reflections
b = 15.660 (3) Å	θ = 2.0–22.7°
c = 18.678 (3) Å	µ = 0.07 mm^−1
β = 92.626 (3)°	T = 291 K
V = 1825.1 (6) Å^3	Block, colourless
Z = 4	0.30 × 0.26 × 0.24 mm

Data collection

Bruker SMART APEX CCD diffractometer	3582 independent reflections
Radiation source: sealed tube	1936 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.076
φ and ω scans	θmax = 26.0°, θmin = 1.7°
Absorption correction: multi-scan (SADABS; Bruker, 2000)	h = −7→6
Tmin = 0.98, Tmax = 0.98	k = −17→19
9859 measured reflections	l = −23→22

Refinement

Refinement on F^2	Secondary atom site location: difference Fourier map
Least-squares matrix: full	Hydrogen site location: inferred from neighbouring sites
R[F^2 > 2σ(F^2)] = 0.057	H-atom parameters constrained
wR(F^2) = 0.163	w = 1/[σ^2(Fo^2) + (0.0627P)^2 + 0.22P] where P = (Fo^2 + 2Fc^2)/3
S = 1.02	(Δ/σ)max < 0.001
3582 reflections	Δρmax = 0.41 e Å^−3
209 parameters	Δρmin = −0.44 e Å^−3
0 restraints	Extinction correction: SHELXL97, Fc^*=kFc[1+0.001xFc^2λ^3/sin(2θ)]^-1/4
Primary atom site location: structure-invariant direct methods	Extinction coefficient: 0.014 (2)

Special details

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
C1	0.2032 (3)	1.00147 (14)	0.40692 (10)	0.0443 (5)
C2	0.3784 (3)	1.05636 (14)	0.41193 (11)	0.0502 (6)
H2A	0.5075	1.0368	0.4327	0.060*
C3	0.3649 (3)	1.13866 (15)	0.38690 (11)	0.0520 (6)
H3A	0.4865	1.1729	0.3908	0.062*
C4	0.1770 (3)	1.17320 (14)	0.35592 (11)	0.0484 (5)
C5	0.0018 (3)	1.11941 (15)	0.35419 (12)	0.0567 (6)
H5A	−0.1291	1.1401	0.3359	0.068*
C6	0.0129 (3)	1.03582 (15)	0.37851 (12)	0.0551 (6)
H6A	−0.1097	1.0021	0.3757	0.066*
C7	0.1724 (4)	1.26349 (16)	0.32499 (14)	0.0665 (7)
C8	0.2652 (5)	1.32704 (16)	0.37979 (14)	0.0779 (8)
H8A	0.1817	1.3261	0.4217	0.117*
H8B	0.2616	1.3834	0.3595	0.117*
H8C	0.4107	1.3117	0.3928	0.117*
C9	0.3050 (4)	1.26483 (17)	0.25829 (14)	0.0740 (8)
H9A	0.2463	1.2248	0.2238	0.111*
H9B	0.4505	1.2495	0.2712	0.111*
H9C	0.3017	1.3211	0.2379	0.111*
C10	−0.0545 (4)	1.29243 (18)	0.30268 (18)	0.0917 (10)
H10A	−0.1419	1.2916	0.3436	0.138*
H10B	−0.1142	1.2545	0.2667	0.138*
H10C	−0.0499	1.3494	0.2837	0.138*
C11	0.0280 (3)	0.86599 (14)	0.43128 (13)	0.0566 (6)
H11A	−0.0328	0.8606	0.3828	0.068*
H11B	−0.0753	0.8954	0.4597	0.068*
C12	0.0705 (4)	0.77838 (14)	0.46212 (13)	0.0626 (7)
H12A	0.1251	0.7836	0.5114	0.075*
H12B	−0.0625	0.7464	0.4620	0.075*
C13	0.4252 (3)	0.78128 (14)	0.42316 (13)	0.0564 (6)
H13A	0.5311	0.7517	0.3960	0.068*
H13B	0.4802	0.7856	0.4724	0.068*
C14	0.3895 (3)	0.86910 (14)	0.39285 (13)	0.0557 (6)
H14A	0.5232	0.9007	0.3964	0.067*
H14B	0.3454	0.8646	0.3425	0.067*
C15	0.2581 (4)	0.64518 (15)	0.44677 (13)	0.0666 (7)
H15A	0.1201	0.6173	0.4500	0.080*
H15B	0.3262	0.6468	0.4945	0.080*
C16	0.3948 (4)	0.59459 (14)	0.39815 (13)	0.0587 (6)
C17	0.3258 (5)	0.58144 (16)	0.32781 (14)	0.0713 (7)
H17A	0.1923	0.6020	0.3118	0.086*
C18	0.4506 (6)	0.53853 (17)	0.28085 (16)	0.0853 (9)
H18A	0.4012	0.5302	0.2336	0.102*
C19	0.6471 (6)	0.50819 (18)	0.30353 (19)	0.0886 (9)
H19A	0.7332	0.4805	0.2715	0.106*
C20	0.7175 (5)	0.51851 (18)	0.3737 (2)	0.0915 (9)
H20A	0.8495	0.4964	0.3895	0.110*
C21	0.5909 (5)	0.56214 (17)	0.42110 (16)	0.0767 (8)
H21A	0.6392	0.5694	0.4686	0.092*
N1	0.2256 (3)	0.91600 (11)	0.43064 (9)	0.0465 (5)
N2	0.2257 (3)	0.73258 (11)	0.42046 (10)	0.0537 (5)

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
C1	0.0382 (12)	0.0529 (13)	0.0420 (12)	0.0010 (10)	0.0038 (9)	−0.0059 (10)
C2	0.0406 (12)	0.0578 (14)	0.0517 (13)	0.0029 (11)	−0.0034 (10)	−0.0002 (11)
C3	0.0437 (13)	0.0569 (14)	0.0554 (14)	−0.0045 (11)	0.0029 (10)	−0.0019 (11)
C4	0.0454 (13)	0.0547 (14)	0.0454 (12)	0.0056 (11)	0.0039 (10)	−0.0041 (10)
C5	0.0423 (13)	0.0612 (15)	0.0661 (15)	0.0099 (11)	−0.0033 (11)	−0.0035 (12)
C6	0.0376 (12)	0.0570 (15)	0.0703 (16)	−0.0013 (10)	−0.0004 (11)	−0.0063 (12)
C7	0.0689 (17)	0.0673 (17)	0.0637 (16)	0.0067 (13)	0.0061 (13)	0.0045 (13)
C8	0.0897 (19)	0.0587 (16)	0.085 (2)	−0.0157 (15)	−0.0032 (16)	0.0044 (14)
C9	0.0711 (17)	0.0752 (18)	0.0761 (18)	0.0067 (14)	0.0061 (14)	0.0045 (14)
C10	0.078 (2)	0.0697 (18)	0.127 (3)	0.0238 (15)	−0.0008 (18)	0.0175 (17)
C11	0.0456 (13)	0.0612 (15)	0.0637 (15)	−0.0014 (11)	0.0114 (11)	−0.0059 (12)
C12	0.0605 (15)	0.0610 (15)	0.0680 (16)	−0.0056 (12)	0.0191 (12)	−0.0020 (12)
C13	0.0522 (14)	0.0550 (14)	0.0626 (15)	0.0048 (11)	0.0081 (11)	−0.0022 (11)
C14	0.0475 (13)	0.0551 (14)	0.0654 (15)	0.0009 (11)	0.0122 (11)	−0.0011 (11)
C15	0.0813 (18)	0.0550 (15)	0.0645 (16)	−0.0032 (13)	0.0150 (14)	0.0039 (12)
C16	0.0743 (17)	0.0439 (13)	0.0586 (16)	−0.0006 (12)	0.0085 (13)	0.0044 (11)
C17	0.0905 (19)	0.0597 (16)	0.0637 (17)	0.0102 (14)	0.0056 (15)	0.0045 (13)
C18	0.123 (3)	0.0652 (18)	0.0680 (18)	0.0162 (18)	0.0103 (18)	0.0012 (14)
C19	0.106 (3)	0.0671 (19)	0.095 (2)	0.0096 (18)	0.030 (2)	−0.0068 (17)
C20	0.078 (2)	0.0691 (19)	0.127 (3)	0.0131 (15)	0.002 (2)	−0.0091 (19)
C21	0.084 (2)	0.0637 (17)	0.0812 (19)	0.0018 (15)	−0.0044 (16)	−0.0062 (14)
N1	0.0395 (10)	0.0503 (11)	0.0500 (11)	0.0003 (8)	0.0061 (8)	−0.0034 (8)
N2	0.0557 (12)	0.0506 (11)	0.0558 (11)	−0.0026 (9)	0.0121 (9)	−0.0025 (9)

Geometric parameters (Å, º)

C1—C6	1.388 (3)	C11—H11B	0.9700
C1—C2	1.392 (3)	C12—N2	1.459 (3)
C1—N1	1.415 (3)	C12—H12A	0.9700
C2—C3	1.372 (3)	C12—H12B	0.9700
C2—H2A	0.9300	C13—N2	1.460 (3)
C3—C4	1.393 (3)	C13—C14	1.500 (3)
C3—H3A	0.9300	C13—H13A	0.9700
C4—C5	1.380 (3)	C13—H13B	0.9700
C4—C7	1.527 (3)	C14—N1	1.467 (2)
C5—C6	1.386 (3)	C14—H14A	0.9700
C5—H5A	0.9300	C14—H14B	0.9700
C6—H6A	0.9300	C15—N2	1.465 (3)
C7—C8	1.523 (3)	C15—C16	1.501 (3)
C7—C10	1.527 (3)	C15—H15A	0.9700
C7—C9	1.528 (3)	C15—H15B	0.9700
C8—H8A	0.9600	C16—C21	1.376 (3)
C8—H8B	0.9600	C16—C17	1.379 (3)
C8—H8C	0.9600	C17—C18	1.375 (4)
C9—H9A	0.9600	C17—H17A	0.9300
C9—H9B	0.9600	C18—C19	1.365 (4)
C9—H9C	0.9600	C18—H18A	0.9300
C10—H10A	0.9600	C19—C20	1.372 (4)
C10—H10B	0.9600	C19—H19A	0.9300
C10—H10C	0.9600	C20—C21	1.393 (4)
C11—N1	1.462 (3)	C20—H20A	0.9300
C11—C12	1.507 (3)	C21—H21A	0.9300
C11—H11A	0.9700
C6—C1—C2	116.3 (2)	N2—C12—C11	110.70 (18)
C6—C1—N1	123.87 (19)	N2—C12—H12A	109.5
C2—C1—N1	119.79 (18)	C11—C12—H12A	109.5
C3—C2—C1	121.4 (2)	N2—C12—H12B	109.5
C3—C2—H2A	119.3	C11—C12—H12B	109.5
C1—C2—H2A	119.3	H12A—C12—H12B	108.1
C2—C3—C4	122.9 (2)	N2—C13—C14	110.72 (18)
C2—C3—H3A	118.5	N2—C13—H13A	109.5
C4—C3—H3A	118.5	C14—C13—H13A	109.5
C5—C4—C3	115.1 (2)	N2—C13—H13B	109.5
C5—C4—C7	123.7 (2)	C14—C13—H13B	109.5
C3—C4—C7	121.2 (2)	H13A—C13—H13B	108.1
C4—C5—C6	122.8 (2)	N1—C14—C13	111.87 (18)
C4—C5—H5A	118.6	N1—C14—H14A	109.2
C6—C5—H5A	118.6	C13—C14—H14A	109.2
C5—C6—C1	121.4 (2)	N1—C14—H14B	109.2
C5—C6—H6A	119.3	C13—C14—H14B	109.2
C1—C6—H6A	119.3	H14A—C14—H14B	107.9
C8—C7—C4	110.5 (2)	N2—C15—C16	111.34 (19)
C8—C7—C10	108.0 (2)	N2—C15—H15A	109.4
C4—C7—C10	112.3 (2)	C16—C15—H15A	109.4
C8—C7—C9	109.6 (2)	N2—C15—H15B	109.4
C4—C7—C9	108.6 (2)	C16—C15—H15B	109.4
C10—C7—C9	107.7 (2)	H15A—C15—H15B	108.0
C7—C8—H8A	109.5	C21—C16—C17	118.5 (2)
C7—C8—H8B	109.5	C21—C16—C15	122.0 (2)
H8A—C8—H8B	109.5	C17—C16—C15	119.6 (2)
C7—C8—H8C	109.5	C18—C17—C16	121.2 (3)
H8A—C8—H8C	109.5	C18—C17—H17A	119.4
H8B—C8—H8C	109.5	C16—C17—H17A	119.4
C7—C9—H9A	109.5	C19—C18—C17	120.0 (3)
C7—C9—H9B	109.5	C19—C18—H18A	120.0
H9A—C9—H9B	109.5	C17—C18—H18A	120.0
C7—C9—H9C	109.5	C18—C19—C20	120.0 (3)
H9A—C9—H9C	109.5	C18—C19—H19A	120.0
H9B—C9—H9C	109.5	C20—C19—H19A	120.0
C7—C10—H10A	109.5	C19—C20—C21	119.9 (3)
C7—C10—H10B	109.5	C19—C20—H20A	120.1
H10A—C10—H10B	109.5	C21—C20—H20A	120.1
C7—C10—H10C	109.5	C16—C21—C20	120.4 (3)
H10A—C10—H10C	109.5	C16—C21—H21A	119.8
H10B—C10—H10C	109.5	C20—C21—H21A	119.8
N1—C11—C12	110.90 (19)	C1—N1—C11	115.95 (17)
N1—C11—H11A	109.5	C1—N1—C14	112.61 (15)
C12—C11—H11A	109.5	C11—N1—C14	110.10 (16)
N1—C11—H11B	109.5	C12—N2—C13	108.17 (17)
C12—C11—H11B	109.5	C12—N2—C15	111.43 (17)
H11A—C11—H11B	108.0	C13—N2—C15	111.82 (19)