r-1,c-2,t-3,t-4-1,2-Bis(4-methoxy­phenyl)-3,4-bis(5-phenyl-1,3,4-oxa­diazol-2-yl)­cyclo­butane

The title compound, C₃₄H₂₈N₄O₄, is a derivative of di­phenyl­oxa­diazo­lylcyclo­butane (s-DPC), and although it is a syn-head-to-head photodimer, it does not display molecular mirror symmetry in the crystalline state. The cyclo­butane ring has a puckered conformation, with a dihedral angle of 30°, which is the largest among tetra­aryl-substituted cyclo­butanes reported so far. The four C-C single bonds of the cyclo­butane ring differ from each other. One is the same length as a typical C-C single bond, while the others are longer. The photodimerization of the corresponding monomer yields only 1% of s-DPC, suggesting that the head-to-head reaction is a minor photodimerization process.

Key indicators

• Single-crystal X-ray study
• T = 298 K
• Mean [sigma](C-C) = 0.003 Å
• R factor = 0.044
• wR factor = 0.133
• Data-to-parameter ratio = 13.1

checkCIF results

No syntax errors found

ADDSYM reports no extra symmetry

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Computing details

Data collection: SMART (Bruker, 1998); cell refinement: SMART; data reduction: SHELXTL (Bruker, 1998); program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: SHELXTL; software used to prepare material for publication: SHELXTL.

r-1,c-2,t-3,t-4–1,2-Bis(4-methoxyphenyl)-3,4-bis(5-phenyl-1,3,4- oxadiazol-2-yl)cyclobutane

Crystal data

C34H28N4O4	Z = 2
Mr = 556.60	F(000) = 584
Triclinic, P1	Dx = 1.280 Mg m^−3
a = 9.1746 (8) Å	Mo Kα radiation, λ = 0.71073 Å
b = 11.3853 (10) Å	Cell parameters from 5978 reflections
c = 14.5431 (12) Å	θ = 1.5–25.0°
α = 91.648 (2)°	µ = 0.09 mm^−1
β = 107.925 (2)°	T = 298 K
γ = 91.642 (2)°	Plate, colorless
V = 1443.6 (2) Å^3	0.35 × 0.30 × 0.30 mm

Data collection

Bruker SMART CCD area-detector diffractometer	3382 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tube	Rint = 0.012
Graphite monochromator	θmax = 25.0°, θmin = 1.5°
φ and ω scans	h = −10→7
6052 measured reflections	k = −13→13
5079 independent reflections	l = −17→17

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)] = 0.044	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.133	H-atom parameters constrained
S = 1.00	w = 1/[σ^2(Fo^2) + (0.0766P)^2 + 0.0284P] where P = (Fo^2 + 2Fc^2)/3
5079 reflections	(Δ/σ)max < 0.001
388 parameters	Δρmax = 0.13 e Å^−3
0 restraints	Δρmin = −0.16 e Å^−3

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	Occ. (<1)
O1	0.50164 (12)	0.37503 (9)	0.19416 (9)	0.0552 (3)
N1	0.71024 (18)	0.44520 (14)	0.30374 (13)	0.0706 (5)
C1	0.6322 (2)	0.23538 (14)	0.31280 (13)	0.0552 (5)
H1A	0.7371	0.2239	0.3540	0.066*
O2	0.37046 (14)	0.37125 (10)	0.35694 (9)	0.0609 (3)
C2	0.57560 (19)	0.12783 (14)	0.24310 (12)	0.0521 (4)
H2A	0.4865	0.1502	0.1902	0.062*
N2	0.64559 (19)	0.53618 (13)	0.24209 (13)	0.0718 (5)
O3	0.93683 (19)	−0.24599 (12)	0.54582 (11)	0.0950 (5)
N3	0.24367 (18)	0.22046 (14)	0.26664 (13)	0.0713 (5)
C3	0.5156 (2)	0.07018 (15)	0.32276 (13)	0.0567 (5)
H3A	0.4116	0.0354	0.2956	0.068*
N4	0.15029 (18)	0.31896 (15)	0.24854 (14)	0.0734 (5)
C4	0.5160 (2)	0.19590 (16)	0.36706 (14)	0.0595 (5)
H4A	0.5590	0.2014	0.4377	0.071*
O4	0.9684 (2)	−0.11107 (17)	0.07510 (14)	0.1064 (6)
C5	0.62279 (19)	0.35372 (15)	0.27309 (13)	0.0544 (5)
C6	0.5242 (2)	0.49087 (14)	0.17950 (14)	0.0540 (4)
C7	0.3697 (2)	0.25519 (16)	0.32924 (14)	0.0593 (5)
C8	0.2294 (2)	0.40444 (16)	0.30246 (14)	0.0581 (5)
C9	0.9382 (3)	−0.36345 (18)	0.51319 (17)	0.0856 (7)
H9A	1.0178	−0.4033	0.5591	0.128*
H9B	0.9568	−0.3650	0.4517	0.128*
H9C	0.8409	−0.4021	0.5064	0.128*
C10	1.1249 (6)	−0.0921 (5)	0.0994 (4)	0.1022 (17)	0.50
H10A	1.1649	−0.1440	0.0607	0.153*	0.50
H10B	1.1712	−0.1072	0.1666	0.153*	0.50
H10C	1.1476	−0.0120	0.0880	0.153*	0.50
C10'	0.9176 (9)	−0.1814 (7)	0.0021 (7)	0.174 (3)	0.50
H10D	0.8085	−0.1923	−0.0129	0.261*	0.50
H10E	0.9646	−0.2557	0.0163	0.261*	0.50
H10F	0.9411	−0.1494	−0.0522	0.261*	0.50
C11	0.6236 (2)	−0.01364 (15)	0.38470 (13)	0.0558 (5)
C12	0.6231 (2)	−0.12840 (15)	0.35276 (14)	0.0617 (5)
H12A	0.5515	−0.1531	0.2943	0.074*
C13	0.7242 (2)	−0.20894 (16)	0.40350 (15)	0.0657 (5)
H13A	0.7201	−0.2858	0.3791	0.079*
C14	0.8301 (2)	−0.17500 (16)	0.48956 (14)	0.0675 (5)
C15	0.8348 (3)	−0.06057 (18)	0.52350 (16)	0.0916 (8)
H15A	0.9069	−0.0362	0.5818	0.110*
C16	0.7332 (3)	0.01805 (17)	0.47159 (16)	0.0835 (7)
H16A	0.7385	0.0951	0.4958	0.100*
C21	0.6822 (2)	0.06601 (14)	0.19986 (12)	0.0519 (4)
C22	0.6251 (2)	−0.01983 (17)	0.12780 (15)	0.0680 (5)
H22A	0.5204	−0.0383	0.1068	0.082*
C23	0.7195 (3)	−0.07921 (19)	0.08594 (16)	0.0783 (6)
H23A	0.6783	−0.1370	0.0376	0.094*
C24	0.8749 (3)	−0.05263 (18)	0.11598 (16)	0.0702 (6)
C25	0.9338 (2)	0.03328 (18)	0.18649 (15)	0.0688 (5)
H25A	1.0383	0.0525	0.2064	0.083*
C26	0.8387 (2)	0.09148 (16)	0.22821 (14)	0.0621 (5)
H26A	0.8806	0.1492	0.2765	0.074*
C31	0.4161 (2)	0.54561 (15)	0.09864 (13)	0.0546 (5)
C32	0.4515 (3)	0.65460 (17)	0.07104 (16)	0.0729 (6)
H32A	0.5436	0.6937	0.1049	0.087*
C33	0.3509 (3)	0.70593 (19)	−0.00667 (17)	0.0821 (7)
H33A	0.3758	0.7795	−0.0250	0.098*
C34	0.2163 (3)	0.6502 (2)	−0.05652 (17)	0.0828 (7)
H34A	0.1493	0.6850	−0.1093	0.099*
C35	0.1795 (3)	0.5426 (2)	−0.02887 (18)	0.0956 (8)
H35A	0.0864	0.5046	−0.0624	0.115*
C36	0.2796 (2)	0.4898 (2)	0.04862 (17)	0.0830 (7)
H36A	0.2542	0.4163	0.0668	0.100*
C41	0.1906 (2)	0.52707 (16)	0.30812 (14)	0.0577 (5)
C42	0.3027 (2)	0.61386 (18)	0.34783 (16)	0.0714 (6)
H42A	0.4045	0.5940	0.3737	0.086*
C43	0.2637 (3)	0.72967 (19)	0.34902 (18)	0.0816 (6)
H43A	0.3391	0.7882	0.3755	0.098*
C44	0.1131 (3)	0.7587 (2)	0.31096 (18)	0.0834 (7)
H44A	0.0868	0.8369	0.3120	0.100*
C45	0.0021 (3)	0.6733 (2)	0.27161 (18)	0.0835 (7)
H45A	−0.0995	0.6935	0.2456	0.100*
C46	0.0400 (2)	0.55800 (18)	0.27043 (15)	0.0712 (6)
H46A	−0.0362	0.5001	0.2441	0.085*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
O1	0.0530 (7)	0.0464 (7)	0.0586 (8)	0.0042 (5)	0.0058 (6)	0.0047 (5)
N1	0.0632 (10)	0.0516 (9)	0.0803 (12)	0.0037 (8)	−0.0026 (9)	0.0024 (8)
C1	0.0519 (10)	0.0478 (10)	0.0575 (11)	0.0124 (8)	0.0038 (9)	0.0008 (8)
O2	0.0615 (8)	0.0567 (8)	0.0612 (8)	0.0172 (6)	0.0127 (6)	0.0006 (6)
C2	0.0535 (10)	0.0465 (9)	0.0486 (10)	0.0086 (8)	0.0039 (8)	0.0032 (8)
N2	0.0670 (10)	0.0490 (9)	0.0839 (12)	0.0017 (8)	0.0002 (9)	0.0048 (8)
O3	0.1270 (13)	0.0580 (9)	0.0730 (10)	0.0388 (8)	−0.0117 (9)	0.0001 (7)
N3	0.0591 (10)	0.0588 (10)	0.0920 (14)	0.0104 (8)	0.0168 (10)	0.0021 (9)
C3	0.0585 (11)	0.0500 (10)	0.0585 (12)	0.0101 (8)	0.0127 (9)	0.0063 (8)
N4	0.0566 (10)	0.0637 (10)	0.0947 (13)	0.0126 (8)	0.0150 (9)	−0.0006 (10)
C4	0.0656 (12)	0.0557 (11)	0.0535 (11)	0.0174 (9)	0.0112 (9)	0.0057 (9)
O4	0.1210 (15)	0.1124 (14)	0.1014 (14)	0.0254 (12)	0.0570 (12)	−0.0118 (11)
C5	0.0474 (10)	0.0497 (10)	0.0585 (11)	0.0091 (8)	0.0046 (8)	−0.0020 (8)
C6	0.0551 (11)	0.0427 (10)	0.0636 (12)	0.0048 (8)	0.0175 (9)	0.0018 (8)
C7	0.0638 (12)	0.0551 (11)	0.0609 (12)	0.0135 (9)	0.0208 (10)	0.0055 (9)
C8	0.0504 (10)	0.0612 (11)	0.0624 (12)	0.0126 (9)	0.0159 (9)	0.0056 (9)
C9	0.1187 (19)	0.0547 (12)	0.0763 (15)	0.0317 (12)	0.0167 (14)	0.0103 (11)
C10	0.078 (3)	0.141 (5)	0.113 (4)	0.036 (3)	0.063 (3)	0.018 (3)
C10'	0.188 (8)	0.153 (7)	0.208 (9)	−0.004 (6)	0.108 (7)	−0.070 (6)
C11	0.0644 (12)	0.0488 (10)	0.0539 (11)	0.0112 (8)	0.0166 (9)	0.0070 (8)
C12	0.0688 (12)	0.0513 (11)	0.0582 (12)	0.0041 (9)	0.0094 (9)	0.0016 (9)
C13	0.0813 (13)	0.0439 (10)	0.0671 (13)	0.0118 (9)	0.0148 (11)	0.0023 (9)
C14	0.0885 (14)	0.0514 (11)	0.0545 (12)	0.0231 (10)	0.0077 (11)	0.0068 (9)
C15	0.1205 (19)	0.0637 (13)	0.0620 (14)	0.0336 (13)	−0.0157 (13)	−0.0071 (11)
C16	0.1155 (18)	0.0517 (12)	0.0637 (14)	0.0307 (12)	−0.0032 (13)	−0.0049 (10)
C21	0.0581 (11)	0.0458 (9)	0.0468 (10)	0.0071 (8)	0.0079 (8)	0.0075 (8)
C22	0.0682 (13)	0.0679 (12)	0.0659 (13)	−0.0063 (10)	0.0194 (10)	−0.0075 (10)
C23	0.0969 (17)	0.0689 (13)	0.0708 (15)	−0.0079 (12)	0.0313 (13)	−0.0180 (11)
C24	0.0824 (15)	0.0663 (13)	0.0710 (14)	0.0118 (11)	0.0360 (12)	0.0064 (11)
C25	0.0636 (12)	0.0697 (13)	0.0716 (14)	0.0088 (10)	0.0180 (11)	0.0034 (11)
C26	0.0624 (12)	0.0556 (11)	0.0609 (12)	0.0083 (9)	0.0081 (10)	−0.0003 (9)
C31	0.0554 (11)	0.0530 (10)	0.0572 (11)	0.0102 (8)	0.0189 (9)	0.0067 (9)
C32	0.0785 (14)	0.0561 (12)	0.0779 (15)	0.0056 (10)	0.0140 (11)	0.0105 (11)
C33	0.1010 (18)	0.0639 (13)	0.0794 (16)	0.0149 (13)	0.0225 (14)	0.0195 (12)
C34	0.0858 (17)	0.0927 (17)	0.0680 (15)	0.0274 (14)	0.0167 (13)	0.0254 (13)
C35	0.0704 (15)	0.117 (2)	0.0841 (17)	−0.0050 (14)	−0.0005 (12)	0.0329 (15)
C36	0.0727 (14)	0.0836 (15)	0.0799 (16)	−0.0083 (12)	0.0038 (12)	0.0269 (12)
C41	0.0572 (11)	0.0585 (11)	0.0604 (12)	0.0136 (9)	0.0210 (9)	0.0057 (9)
C42	0.0612 (12)	0.0686 (13)	0.0822 (15)	0.0149 (10)	0.0183 (11)	−0.0030 (11)
C43	0.0834 (16)	0.0623 (13)	0.1006 (18)	0.0060 (12)	0.0310 (14)	−0.0063 (12)
C44	0.0960 (18)	0.0624 (13)	0.0934 (18)	0.0277 (13)	0.0289 (14)	0.0083 (12)
C45	0.0728 (14)	0.0769 (15)	0.0949 (17)	0.0301 (12)	0.0147 (13)	0.0051 (13)
C46	0.0586 (12)	0.0700 (13)	0.0827 (15)	0.0153 (10)	0.0175 (11)	0.0035 (11)

Geometric parameters (Å, º)

O1—C6	1.3621 (19)	C12—C13	1.383 (3)
O1—C5	1.3631 (19)	C12—H12A	0.9300
N1—C5	1.278 (2)	C13—C14	1.364 (3)
N1—N2	1.411 (2)	C13—H13A	0.9300
C1—C5	1.475 (2)	C14—C15	1.375 (3)
C1—C2	1.538 (2)	C15—C16	1.376 (3)
C1—C4	1.572 (3)	C15—H15A	0.9300
C1—H1A	0.9800	C16—H16A	0.9300
O2—C8	1.364 (2)	C21—C22	1.379 (2)
O2—C7	1.369 (2)	C21—C26	1.385 (2)
C2—C21	1.497 (2)	C22—C23	1.383 (3)
C2—C3	1.579 (2)	C22—H22A	0.9300
C2—H2A	0.9800	C23—C24	1.378 (3)
N2—C6	1.285 (2)	C23—H23A	0.9300
O3—C14	1.368 (2)	C24—C25	1.368 (3)
O3—C9	1.408 (2)	C25—C26	1.380 (3)
N3—C7	1.276 (2)	C25—H25A	0.9300
N3—N4	1.412 (2)	C26—H26A	0.9300
C3—C11	1.503 (2)	C31—C36	1.366 (3)
C3—C4	1.552 (2)	C31—C32	1.376 (3)
C3—H3A	0.9800	C32—C33	1.378 (3)
N4—C8	1.286 (2)	C32—H32A	0.9300
C4—C7	1.476 (2)	C33—C34	1.353 (3)
C4—H4A	0.9800	C33—H33A	0.9300
O4—C10'	1.269 (8)	C34—C35	1.366 (3)
O4—C24	1.362 (3)	C34—H34A	0.9300
O4—C10	1.378 (5)	C35—C36	1.382 (3)
C6—C31	1.454 (2)	C35—H35A	0.9300
C8—C41	1.457 (2)	C36—H36A	0.9300
C9—H9A	0.9600	C41—C46	1.381 (3)
C9—H9B	0.9600	C41—C42	1.382 (3)
C9—H9C	0.9600	C42—C43	1.377 (3)
C10—H10A	0.9600	C42—H42A	0.9300
C10—H10B	0.9600	C43—C44	1.375 (3)
C10—H10C	0.9600	C43—H43A	0.9300
C10'—H10D	0.9600	C44—C45	1.365 (3)
C10'—H10E	0.9600	C44—H44A	0.9300
C10'—H10F	0.9600	C45—C46	1.369 (3)
C11—C12	1.373 (2)	C45—H45A	0.9300
C11—C16	1.382 (3)	C46—H46A	0.9300
C6—O1—C5	103.09 (13)	C11—C12—H12A	118.5
C5—N1—N2	106.55 (15)	C13—C12—H12A	118.5
C5—C1—C2	119.08 (15)	C14—C13—C12	119.62 (17)
C5—C1—C4	119.34 (14)	C14—C13—H13A	120.2
C2—C1—C4	88.40 (13)	C12—C13—H13A	120.2
C5—C1—H1A	109.4	C13—C14—O3	125.08 (17)
C2—C1—H1A	109.4	C13—C14—C15	119.01 (18)
C4—C1—H1A	109.4	O3—C14—C15	115.90 (18)
C8—O2—C7	102.63 (14)	C14—C15—C16	120.3 (2)
C21—C2—C1	120.77 (15)	C14—C15—H15A	119.8
C21—C2—C3	121.71 (14)	C16—C15—H15A	119.8
C1—C2—C3	88.14 (13)	C15—C16—C11	122.19 (19)
C21—C2—H2A	108.1	C15—C16—H16A	118.9
C1—C2—H2A	108.1	C11—C16—H16A	118.9
C3—C2—H2A	108.1	C22—C21—C26	117.19 (18)
C6—N2—N1	106.24 (14)	C22—C21—C2	119.83 (16)
C14—O3—C9	117.95 (16)	C26—C21—C2	122.98 (16)
C7—N3—N4	106.34 (16)	C21—C22—C23	121.72 (19)
C11—C3—C4	116.45 (15)	C21—C22—H22A	119.1
C11—C3—C2	114.27 (14)	C23—C22—H22A	119.1
C4—C3—C2	87.64 (13)	C24—C23—C22	119.9 (2)
C11—C3—H3A	112.1	C24—C23—H23A	120.1
C4—C3—H3A	112.1	C22—C23—H23A	120.1
C2—C3—H3A	112.1	O4—C24—C25	120.5 (2)
C8—N4—N3	106.36 (16)	O4—C24—C23	120.1 (2)
C7—C4—C3	114.17 (16)	C25—C24—C23	119.44 (19)
C7—C4—C1	110.68 (15)	C24—C25—C26	120.2 (2)
C3—C4—C1	87.89 (13)	C24—C25—H25A	119.9
C7—C4—H4A	113.8	C26—C25—H25A	119.9
C3—C4—H4A	113.8	C25—C26—C21	121.56 (19)
C1—C4—H4A	113.8	C25—C26—H26A	119.2
C10'—O4—C24	122.8 (4)	C21—C26—H26A	119.2
C10'—O4—C10	111.7 (4)	C36—C31—C32	119.16 (19)
C24—O4—C10	125.1 (3)	C36—C31—C6	120.95 (17)
N1—C5—O1	112.13 (15)	C32—C31—C6	119.89 (17)
N1—C5—C1	129.65 (17)	C31—C32—C33	120.2 (2)
O1—C5—C1	118.17 (15)	C31—C32—H32A	119.9
N2—C6—O1	111.99 (16)	C33—C32—H32A	119.9
N2—C6—C31	129.02 (16)	C34—C33—C32	120.6 (2)
O1—C6—C31	118.99 (15)	C34—C33—H33A	119.7
N3—C7—O2	112.50 (16)	C32—C33—H33A	119.7
N3—C7—C4	130.89 (18)	C33—C34—C35	119.6 (2)
O2—C7—C4	116.21 (17)	C33—C34—H34A	120.2
N4—C8—O2	112.16 (16)	C35—C34—H34A	120.2
N4—C8—C41	129.04 (17)	C34—C35—C36	120.4 (2)
O2—C8—C41	118.73 (17)	C34—C35—H35A	119.8
O3—C9—H9A	109.5	C36—C35—H35A	119.8
O3—C9—H9B	109.5	C31—C36—C35	120.1 (2)
H9A—C9—H9B	109.5	C31—C36—H36A	120.0
O3—C9—H9C	109.5	C35—C36—H36A	120.0
H9A—C9—H9C	109.5	C46—C41—C42	119.23 (18)
H9B—C9—H9C	109.5	C46—C41—C8	119.57 (18)
O4—C10—H10A	109.5	C42—C41—C8	121.17 (17)
O4—C10—H10B	109.5	C43—C42—C41	120.0 (2)
H10A—C10—H10B	109.5	C43—C42—H42A	120.0
O4—C10—H10C	109.5	C41—C42—H42A	120.0
H10A—C10—H10C	109.5	C44—C43—C42	119.9 (2)
H10B—C10—H10C	109.5	C44—C43—H43A	120.1
O4—C10'—H10D	109.5	C42—C43—H43A	120.1
O4—C10'—H10E	109.5	C45—C44—C43	120.3 (2)
H10D—C10'—H10E	109.5	C45—C44—H44A	119.8
O4—C10'—H10F	109.5	C43—C44—H44A	119.8
H10D—C10'—H10F	109.5	C44—C45—C46	120.1 (2)
H10E—C10'—H10F	109.5	C44—C45—H45A	120.0
C12—C11—C16	115.86 (17)	C46—C45—H45A	120.0
C12—C11—C3	119.77 (17)	C45—C46—C41	120.5 (2)
C16—C11—C3	124.27 (16)	C45—C46—H46A	119.8
C11—C12—C13	123.01 (18)	C41—C46—H46A	119.8