A comparison of 2,7-di­hydro-2,2,7,7-tetra­methyl-3,6-di­phenyl-1,4,5-thiadiazepine and the corresponding 1,1-­dioxide

The structures of the highly substituted title heterocycles, C₂₀H₂₂N₂S and C₂₀H₂₂N₂O₂S, have been determined at 123 (1) K. Both mol­ecules possess exact C₂ symmetry and the seven-membered rings have very similar twist-boat conformations. The magnitudes of the C-S-C bond angles, 107.13 (6) and 108.27 (7)°, respectively, are influenced significantly by the four substituent methyl groups on the seven-membered rings.

Computing details

For both compounds, data collection: SMART (Bruker, 1999); cell refinement: SMART and SAINT (Bruker, 1999); data reduction: SAINT; program(s) used to solve structure: SHELXTL (Sheldrick, 1997); program(s) used to refine structure: SHELXTL; molecular graphics: SHELXTL; software used to prepare material for publication: SHELXTL.

(I) 2,7–dihydro–2,2,7,7–tetramethyl–3,6–diphenyl–1,4,5–thiadiazepine

Crystal data

C20H22N2S	Dx = 1.235 Mg m^−3
Mr = 322.46	Melting point = 480–481 K
Orthorhombic, Pbcn	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2n 2ab	Cell parameters from 4415 reflections
a = 19.4661 (7) Å	θ = 3.3–29.3°
b = 10.7312 (4) Å	µ = 0.19 mm^−1
c = 8.3000 (3) Å	T = 123 K
V = 1733.83 (11) Å^3	Prism, colourless
Z = 4	0.30 × 0.25 × 0.20 mm
F(000) = 688

Data collection

Bruker AXS 1K CCD area detector diffractometer	1856 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tube	Rint = 0.025
Graphite monochromator	θmax = 28.3°, θmin = 2.1°
Detector resolution: 8.192 pixels mm^-1	h = −25→25
narrow frame ω scans	k = −13→14
15326 measured reflections	l = −11→11
2138 independent reflections

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)] = 0.034	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.122	H-atom parameters constrained
S = 1.01	w = 1/[σ^2(Fo^2) + (0.101P)^2] where P = (Fo^2 + 2Fc^2)/3
2138 reflections	(Δ/σ)max < 0.001
118 parameters	Δρmax = 0.31 e Å^−3
0 restraints	Δρmin = −0.26 e Å^−3

Special details

Experimental. The data collection for compound 1 nominally covered a sphere of reciprocal space by a combination of three sets of exposures; each set had a different φ angle for the crystal, 0, 120 and 240° repectively. Each exposure covered 0.3° in ω with a 10 second correlated frame time. A total of 600 frames were accumalated in each ω sweep. The crystal to detector distance was 4.805 cm. Coverage of the unique set was 95.0% to 29.13° in θ, (0.73 Å) and 99.4% complete to 28.28° in θ, (0.75 Å). Crystal decay was monitored by repeating the initial 50 frames at the end of data collection and analyzing the duplicate reflections, a further 50 frames of data were collected at positive 2θ to improve cell refinement statistics. A similar data collection protocol was employed for compound 2 with the following minor differences. The correlated frame time set was 30 s and the crystal to detector distance was 4.808 cm. Coverage of the unique set was 95.6% to 29.13° in θ, (0.72 Å) and 99.9% complete to 28.28° in θ, (0.75 Å). The data for both structures were trucatated to 0.75 Å for structure refinement. Area detector scaling and absorption corrections were performed by SADABS. This correction was used to scale the frames of data and to correct for absorption of the primary beam by the crystal support using the method of Blessing (1995). A correction for absorption of the primary beam by the crystal was not applied and as such no transmission factors are quoted.

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
S1	0.5000	0.63132 (3)	0.2500	0.01967 (16)
N1	0.46419 (5)	0.93154 (9)	0.24404 (10)	0.0205 (2)
C1	0.31407 (6)	0.77649 (11)	0.23485 (13)	0.0237 (3)
H1	0.3333	0.7112	0.2976	0.032 (4)*
C2	0.24317 (6)	0.78969 (12)	0.22544 (15)	0.0281 (3)
H2	0.2141	0.7336	0.2820	0.044 (4)*
C3	0.21472 (6)	0.88491 (11)	0.13337 (14)	0.0275 (3)
H3	0.1662	0.8938	0.1267	0.032 (4)*
C4	0.25719 (6)	0.96681 (11)	0.05143 (14)	0.0282 (3)
H4	0.2377	1.0320	−0.0112	0.034 (4)*
C5	0.32849 (5)	0.95394 (10)	0.06048 (14)	0.0241 (3)
H5	0.3574	1.0102	0.0038	0.033 (4)*
C6	0.35727 (5)	0.85870 (9)	0.15253 (12)	0.0180 (2)
C7	0.43389 (5)	0.84594 (9)	0.16310 (12)	0.0177 (2)
C8	0.46950 (5)	0.73379 (10)	0.08541 (12)	0.0182 (2)
C9	0.41972 (6)	0.65144 (11)	−0.01157 (14)	0.0263 (3)
H9A	0.4001	0.7000	−0.1004	0.042 (4)*
H9B	0.3827	0.6223	0.0590	0.027 (3)*
H9C	0.4446	0.5796	−0.0551	0.037 (4)*
C10	0.52761 (5)	0.77298 (11)	−0.02946 (14)	0.0249 (3)
H10A	0.5099	0.8331	−0.1080	0.063 (6)*
H10B	0.5451	0.6994	−0.0862	0.041 (4)*
H10C	0.5649	0.8113	0.0326	0.039 (4)*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
S1	0.0234 (2)	0.0141 (2)	0.0215 (3)	0.000	0.00039 (12)	0.000
N1	0.0192 (5)	0.0174 (5)	0.0248 (5)	0.0016 (3)	−0.0052 (3)	0.0015 (3)
C1	0.0231 (6)	0.0233 (6)	0.0247 (6)	0.0031 (4)	0.0024 (4)	0.0031 (4)
C2	0.0221 (6)	0.0300 (7)	0.0322 (6)	−0.0008 (5)	0.0076 (4)	0.0017 (5)
C3	0.0173 (5)	0.0321 (6)	0.0330 (6)	0.0035 (4)	−0.0018 (4)	−0.0046 (5)
C4	0.0232 (5)	0.0288 (6)	0.0325 (6)	0.0056 (4)	−0.0068 (5)	0.0034 (5)
C5	0.0217 (5)	0.0223 (6)	0.0284 (6)	−0.0014 (4)	−0.0035 (4)	0.0034 (4)
C6	0.0178 (5)	0.0185 (5)	0.0177 (5)	0.0014 (4)	−0.0025 (4)	−0.0039 (3)
C7	0.0183 (5)	0.0171 (5)	0.0176 (5)	0.0006 (4)	−0.0013 (4)	0.0024 (3)
C8	0.0164 (4)	0.0203 (5)	0.0178 (5)	0.0001 (4)	−0.0001 (4)	−0.0012 (4)
C9	0.0210 (5)	0.0299 (6)	0.0279 (6)	0.0003 (4)	−0.0028 (4)	−0.0113 (4)
C10	0.0234 (5)	0.0342 (6)	0.0170 (5)	−0.0028 (4)	0.0021 (4)	0.0013 (4)

Geometric parameters (Å, º)

S1—C8^i	1.8515 (11)	C8—C9	1.5387 (14)
S1—C8	1.8515 (11)	C1—H1	0.9500
N1—C7	1.2818 (14)	C2—H2	0.9500
N1—N1^i	1.3977 (18)	C3—H3	0.9500
C1—C2	1.3896 (16)	C4—H4	0.9500
C1—C6	1.3972 (15)	C5—H5	0.9500
C2—C3	1.3909 (16)	C9—H9A	0.9800
C3—C4	1.3850 (17)	C9—H9B	0.9800
C4—C5	1.3969 (15)	C9—H9C	0.9800
C5—C6	1.3935 (14)	C10—H10A	0.9800
C6—C7	1.5004 (13)	C10—H10B	0.9800
C7—C8	1.5313 (14)	C10—H10C	0.9800
C8—C10	1.5381 (14)
C10···N1	3.0939 (14)	C10···C7^i	3.2282 (15)
C10···N1^i	2.9210 (14)
C8^i—S1—C8	107.13 (6)	C1—C2—H2	120.0
C7—N1—N1^i	119.75 (8)	C3—C2—H2	120.0
C2—C1—C6	120.39 (11)	C4—C3—H3	120.1
C1—C2—C3	120.07 (11)	C2—C3—H3	120.1
C4—C3—C2	119.89 (10)	C3—C4—H4	119.9
C3—C4—C5	120.26 (10)	C5—C4—H4	119.9
C6—C5—C4	120.09 (10)	C6—C5—H5	120.0
C5—C6—C1	119.29 (10)	C4—C5—H5	120.0
C5—C6—C7	119.90 (9)	C8—C9—H9A	109.5
C1—C6—C7	120.80 (9)	C8—C9—H9B	109.5
N1—C7—C6	115.01 (9)	H9A—C9—H9B	109.5
N1—C7—C8	125.14 (9)	C8—C9—H9C	109.5
C6—C7—C8	119.81 (8)	H9A—C9—H9C	109.5
C7—C8—C10	112.27 (9)	H9B—C9—H9C	109.5
C7—C8—C9	112.75 (8)	C8—C10—H10A	109.5
C10—C8—C9	107.22 (9)	C8—C10—H10B	109.5
C7—C8—S1	107.53 (7)	H10A—C10—H10B	109.5
C10—C8—S1	112.57 (7)	C8—C10—H10C	109.5
C9—C8—S1	104.29 (7)	H10A—C10—H10C	109.5
C2—C1—H1	119.8	H10B—C10—H10C	109.5
C6—C1—H1	119.8
C6—C1—C2—C3	0.17 (18)	C1—C6—C7—N1	−109.25 (11)
C1—C2—C3—C4	−0.19 (17)	C5—C6—C7—C8	−111.83 (11)
C2—C3—C4—C5	0.20 (17)	C1—C6—C7—C8	68.56 (13)
C3—C4—C5—C6	−0.19 (17)	N1—C7—C8—C10	−55.58 (13)
C4—C5—C6—C1	0.18 (16)	C6—C7—C8—C10	126.86 (10)
C4—C5—C6—C7	−179.45 (10)	N1—C7—C8—C9	−176.81 (9)
C2—C1—C6—C5	−0.17 (16)	C6—C7—C8—C9	5.62 (14)
C2—C1—C6—C7	179.45 (11)	N1—C7—C8—S1	68.79 (12)
C7^i—N1^i—N1—C7	−68.75 (17)	C6—C7—C8—S1	−108.78 (9)
N1^i—N1—C7—C6	−177.37 (9)	C8^i—S1—C8—C7	−37.69 (5)
N1^i—N1—C7—C8	4.96 (16)	C8^i—S1—C8—C10	86.49 (7)
C5—C6—C7—N1	70.37 (13)	C8^i—S1—C8—C9	−157.62 (8)

Symmetry code: (i) −x+1, y, −z+1/2.

(II) 2,7–dihydro–2,2,7,7–tetramethyl–3,6–diphenyl–1,4,5–thiadiazepine–1,1 –dioxide

Crystal data

C20H22N2O2S	Dx = 1.322 Mg m^−3
Mr = 354.46	Melting point = 470–472 K
Orthorhombic, Pbcn	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2n 2ab	Cell parameters from 904 reflections
a = 18.9551 (11) Å	θ = 3.2–28.9°
b = 11.4905 (7) Å	µ = 0.20 mm^−1
c = 8.1745 (4) Å	T = 123 K
V = 1780.43 (17) Å^3	Prism, colourless
Z = 4	0.30 × 0.25 × 0.10 mm
F(000) = 752

Data collection

Bruker AXS 1K CCD area detector diffractometer	1815 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tube	Rint = 0.026
Graphite monochromator	θmax = 28.3°, θmin = 2.1°
Detector resolution: 8.192 pixels mm^-1	h = −25→25
narrow frame ω scans	k = −15→15
16286 measured reflections	l = −10→10
2214 independent reflections

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)] = 0.034	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.093	H-atom parameters constrained
S = 1.01	w = 1/[σ^2(Fo^2) + (0.055P)^2 + 0.5P] where P = (Fo^2 + 2Fc^2)/3
2214 reflections	(Δ/σ)max = 0.001
127 parameters	Δρmax = 0.34 e Å^−3
0 restraints	Δρmin = −0.32 e Å^−3

Special details

Experimental. None

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
S1	0.5000	0.65304 (3)	0.2500	0.01915 (13)
O1	0.56050 (5)	0.58857 (8)	0.19229 (12)	0.0298 (2)
N1	0.46367 (5)	0.93214 (8)	0.23939 (12)	0.0188 (2)
C1	0.30821 (7)	0.78723 (12)	0.20616 (17)	0.0254 (3)
H1	0.3256	0.7239	0.2689	0.034 (4)*
C2	0.23573 (7)	0.80182 (13)	0.18545 (19)	0.0314 (3)
H2	0.2039	0.7482	0.2341	0.042 (5)*
C3	0.21003 (7)	0.89407 (13)	0.09437 (19)	0.0326 (3)
H3	0.1606	0.9040	0.0810	0.045 (5)*
C4	0.25638 (7)	0.97166 (13)	0.02287 (19)	0.0341 (3)
H4	0.2387	1.0348	−0.0401	0.049 (5)*
C5	0.32883 (7)	0.95779 (11)	0.04264 (18)	0.0276 (3)
H5	0.3605	1.0114	−0.0069	0.038 (4)*
C6	0.35500 (6)	0.86563 (10)	0.13475 (15)	0.0188 (2)
C7	0.43313 (6)	0.85190 (10)	0.15586 (14)	0.0168 (2)
C8	0.47082 (6)	0.74700 (10)	0.08029 (14)	0.0180 (2)
C9	0.42182 (7)	0.67004 (12)	−0.02354 (16)	0.0257 (3)
H9A	0.4036	0.7153	−0.1160	0.033 (4)*
H9B	0.3823	0.6430	0.0439	0.028 (4)*
H9C	0.4483	0.6028	−0.0646	0.037 (4)*
C10	0.53391 (7)	0.78243 (12)	−0.02785 (15)	0.0250 (3)
H10A	0.5200	0.8467	−0.0997	0.052 (5)*
H10B	0.5487	0.7158	−0.0944	0.039 (5)*
H10C	0.5732	0.8073	0.0418	0.045 (5)*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
S1	0.0217 (2)	0.0134 (2)	0.0224 (2)	0.000	−0.00250 (16)	0.000
O1	0.0311 (5)	0.0222 (5)	0.0362 (5)	0.0099 (4)	−0.0059 (4)	−0.0083 (4)
N1	0.0184 (5)	0.0160 (5)	0.0219 (5)	0.0005 (4)	−0.0025 (4)	0.0019 (4)
C1	0.0228 (6)	0.0268 (7)	0.0267 (7)	0.0009 (5)	0.0029 (5)	0.0041 (5)
C2	0.0217 (6)	0.0341 (7)	0.0384 (8)	−0.0036 (5)	0.0065 (6)	−0.0001 (6)
C3	0.0175 (6)	0.0385 (8)	0.0419 (8)	0.0021 (5)	−0.0034 (6)	−0.0062 (7)
C4	0.0255 (7)	0.0338 (7)	0.0432 (8)	0.0048 (5)	−0.0099 (6)	0.0067 (6)
C5	0.0220 (6)	0.0251 (6)	0.0358 (7)	−0.0015 (5)	−0.0052 (5)	0.0075 (6)
C6	0.0181 (5)	0.0197 (6)	0.0185 (5)	0.0009 (4)	−0.0014 (4)	−0.0023 (5)
C7	0.0191 (5)	0.0158 (5)	0.0155 (5)	0.0008 (4)	0.0003 (4)	0.0033 (4)
C8	0.0193 (5)	0.0185 (5)	0.0164 (5)	0.0003 (4)	−0.0010 (4)	−0.0010 (5)
C9	0.0254 (6)	0.0268 (6)	0.0248 (6)	−0.0004 (5)	−0.0048 (5)	−0.0089 (5)
C10	0.0239 (6)	0.0342 (7)	0.0169 (6)	−0.0010 (5)	0.0032 (5)	−0.0015 (5)

Geometric parameters (Å, º)

S1—O1	1.4444 (9)	C8—C9	1.5379 (16)
S1—O1^i	1.4444 (9)	C8—C10	1.5419 (16)
S1—C8	1.8429 (12)	C1—H1	0.9500
S1—C8^i	1.8429 (12)	C2—H2	0.9500
N1—C7	1.2850 (15)	C3—H3	0.9500
N1—N1^i	1.3882 (19)	C4—H4	0.9500
C1—C2	1.3943 (18)	C5—H5	0.9500
C1—C6	1.3925 (17)	C9—H9A	0.9800
C2—C3	1.384 (2)	C9—H9B	0.9800
C3—C4	1.381 (2)	C9—H9C	0.9800
C4—C5	1.3920 (18)	C10—H10A	0.9800
C5—C6	1.3909 (17)	C10—H10B	0.9800
C6—C7	1.4993 (16)	C10—H10C	0.9800
C7—C8	1.5313 (16)
C10···N1	3.0829 (16)	C10···C7^i	3.2053 (17)
C10···N1^i	2.9191 (16)	H9C···O1^ii	2.4400
O1—S1—O1^i	118.29 (8)	C10—C8—S1	110.70 (8)
O1—S1—C8	107.03 (5)	C2—C1—H1	120.0
O1^i—S1—C8	107.94 (5)	C6—C1—H1	120.0
O1—S1—C8^i	107.94 (5)	C3—C2—H2	119.9
O1^i—S1—C8^i	107.03 (5)	C1—C2—H2	119.9
C8—S1—C8^i	108.27 (7)	C4—C3—H3	120.1
C7—N1—N1^i	120.88 (9)	C2—C3—H3	120.1
C2—C1—C6	119.93 (12)	C3—C4—H4	119.9
C3—C2—C1	120.28 (13)	C5—C4—H4	119.9
C4—C3—C2	119.88 (12)	C6—C5—H5	119.9
C3—C4—C5	120.29 (13)	C4—C5—H5	119.9
C6—C5—C4	120.13 (12)	C8—C9—H9A	109.5
C5—C6—C1	119.49 (11)	C8—C9—H9B	109.5
C5—C6—C7	119.65 (11)	H9A—C9—H9B	109.5
C1—C6—C7	120.86 (11)	C8—C9—H9C	109.5
N1—C7—C6	115.51 (10)	H9A—C9—H9C	109.5
N1—C7—C8	124.68 (10)	H9B—C9—H9C	109.5
C6—C7—C8	119.81 (10)	C8—C10—H10A	109.5
C7—C8—C9	113.18 (10)	C8—C10—H10B	109.5
C7—C8—C10	112.66 (10)	H10A—C10—H10B	109.5
C9—C8—C10	107.69 (10)	C8—C10—H10C	109.5
C7—C8—S1	107.31 (8)	H10A—C10—H10C	109.5
C9—C8—S1	105.06 (8)	H10B—C10—H10C	109.5
C6—C1—C2—C3	−0.1 (2)	N1—C7—C8—C9	−175.78 (11)
C1—C2—C3—C4	0.4 (2)	C6—C7—C8—C9	4.44 (15)
C2—C3—C4—C5	−0.3 (2)	N1—C7—C8—C10	−53.32 (15)
C3—C4—C5—C6	0.0 (2)	C6—C7—C8—C10	126.91 (11)
C4—C5—C6—C1	0.3 (2)	N1—C7—C8—S1	68.78 (13)
C4—C5—C6—C7	−179.71 (13)	C6—C7—C8—S1	−111.00 (10)
C2—C1—C6—C5	−0.2 (2)	O1—S1—C8—C7	−153.75 (8)
C2—C1—C6—C7	179.79 (12)	O1^i—S1—C8—C7	77.92 (9)
C7^i—N1^i—N1—C7	−66.6 (2)	C8^i—S1—C8—C7	−37.62 (6)
N1^i—N1—C7—C6	−176.82 (11)	O1—S1—C8—C9	85.54 (9)
N1^i—N1—C7—C8	3.39 (19)	O1^i—S1—C8—C9	−42.79 (9)
C5—C6—C7—N1	66.64 (15)	C8^i—S1—C8—C9	−158.33 (9)
C1—C6—C7—N1	−113.38 (13)	O1—S1—C8—C10	−30.44 (10)
C5—C6—C7—C8	−113.56 (13)	O1^i—S1—C8—C10	−158.77 (8)
C1—C6—C7—C8	66.42 (16)	C8^i—S1—C8—C10	85.69 (8)

Symmetry codes: (i) −x+1, y, −z+1/2; (ii) −x+1, −y+1, −z.