Bis[2-(benzyl­idene­amino)­phen­yl] disulfide

Wang, Y.; Shi, S.; Han, Y.; Wei, G.-D.

doi:10.1107/S1600536811048239

organic compounds

CRYSTALLOGRAPHIC
COMMUNICATIONS

ISSN: 2056-9890

Volume 67| Part 12| December 2011| Page o3364

https://doi.org/10.1107/S1600536811048239

Open

access

Bis[2-(benzylideneamino)phenyl] disulfide

Yong Wang,^a ^* Shanshan Shi,^a Yanhua Han ^b and Guo-Dong Wei ^c

^aDepartment of Chemistry, Liaocheng University, Liaocheng 252059, People's Republic of China, ^bLiaocheng Labor Technical Schools, Liaocheng 252059, People's Republic of China, and ^cShandong Donge Experimental High School, Donge, Shandong Province 252200, People's Republic of China
^*Correspondence e-mail: yongwang@lcu.edu.cn

(Received 5 November 2011; accepted 14 November 2011; online 19 November 2011)

In the title molecule, C₂₆H₂₀N₂S₂, the two benzene rings connected by a disulfide chain form a dihedral angle of 84.9 (1)°, and the two benzene rings in the two benzylideneaminophenyl fragments form dihedral angles of 34.4 (1) and 32.8 (1)°. The crystal structure exhibits weak intermolecular C—H⋯S hydrogen bonds, which link the molecules into chains along [101].

Related literature

For general background to Schiff bases and their synthesis, see: Wang et al. (1998 ); Bai et al. (2005 ). For a related structure, see: He et al. (2011 ).

Experimental

Crystal data

C₂₆H₂₀N₂S₂
M_r = 424.56
Monoclinic, P 2₁ /n
a = 10.2421 (11) Å
b = 19.672 (2) Å
c = 11.4739 (13) Å
β = 97.198 (1)°
V = 2293.5 (4) Å³
Z = 4
Mo Kα radiation
μ = 0.25 mm⁻¹
T = 298 K
0.43 × 0.35 × 0.31 mm

Data collection

Bruker SMART APEX CCD area-etector diffractometer
Absorption correction: multi-scan (SADABS; Sheldrick, 1996 ) T_min = 0.901, T_max = 0.927
11618 measured reflections
4043 independent reflections
1764 reflections with I > 2σ(I)
R_int = 0.125

Refinement

R[F² > 2σ(F²)] = 0.060
wR(F²) = 0.197
S = 1.05
4043 reflections
271 parameters
H-atom parameters constrained
Δρ_max = 0.27 e Å⁻³
Δρ_min = −0.24 e Å⁻³

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
C5—H5⋯S1ⁱ	0.93	2.86	3.604 (5)	137
Symmetry code: (i) $[x-{\script{1\over 2}}, -y+{\script{1\over 2}}, z-{\script{1\over 2}}]$ .

Data collection: SMART (Bruker, 2007 ); cell refinement: SAINT (Bruker, 2007); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: SHELXTL (Sheldrick, 2008); software used to prepare material for publication: SHELXTL.

Supporting information

Crystal structure: contains datablocks I, global. DOI: https://doi.org/10.1107/S1600536811048239/cv5194sup1.cif

Structure factors: contains datablock I. DOI: https://doi.org/10.1107/S1600536811048239/cv5194Isup2.hkl

Supporting information file. DOI: https://doi.org/10.1107/S1600536811048239/cv5194Isup3.cml

checkCIF report

Comment top

Schiff bases have received considerable attention during the last decades, mainly due to their coordinative and electronic properties (Wang et al., 1998). For this reason, much effort has been devoted to develop effcient routes for the synthesis of these classes of compounds (Bai et al., 2005). In this paper, we report the crystal structure of the title compound, (I), obtained by the reaction of benzaldehyde and 2,2'-diaminodiphenyl disulfide.

In (I) (Fig. 1), the molecule has a trans configuration about the S—S bond. The bond lengths an angles are normal and are comparable to the values observed in N,N'-bis(4-(dimethylamino)benzylidene)-2,2'-diaminodiphenyl disulfide (He et al., 2011). Two benzene rings connected through disulfide chain form a dihedral angle of 84.9 (1)°, and two benzene rings in two benzylideneaniline fragments form the dihedral angles of 34.4 (1) and 32.8 (1)°, respectively.

The crystal packing of the title compound exhibits weak intermolecular C—H···S hydrogen bonds (Table 1), which link molecules into chains along [101].

Related literature top

For general background to Schiff bases and their synthesis, see: Wang et al. (1998); Bai et al. (2005). For a related structure, see: He et al. (2011).

Experimental top

A mixture of benzaldehyde (10 mol), 2,2'-diaminodiphenyl disulfide (5 mol) was refluxed in 20 mL of ethanol for 3.0 hrs. The reaction completion was monitored through thin layer chromatography and the reaction mixture was cooled to room tempertature . The precipitate obtained was filtered, dried and crystallized from ethanol to obtain the title compound.

Structure description top

The crystal packing of the title compound exhibits weak intermolecular C—H···S hydrogen bonds (Table 1), which link molecules into chains along [101].

For general background to Schiff bases and their synthesis, see: Wang et al. (1998); Bai et al. (2005). For a related structure, see: He et al. (2011).

Computing details top

Data collection: SMART (Bruker, 2007); cell refinement: SAINT (Bruker, 2007); data reduction: SAINT (Bruker, 2007); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: SHELXTL (Sheldrick, 2008); software used to prepare material for publication: SHELXTL (Sheldrick, 2008).

Figures top

Fig. 1. The title molecule with the atomic numbering scheme. The displacement ellipsoids are shown at the 30% probability level.

Bis[2-(benzylideneamino)phenyl] disulfide top

Crystal data top

C₂₆H₂₀N₂S₂	F(000) = 888
M_r = 424.56	D_x = 1.230 Mg m⁻³
Monoclinic, P2₁/n	Mo Kα radiation, λ = 0.71073 Å
a = 10.2421 (11) Å	Cell parameters from 2078 reflections
b = 19.672 (2) Å	θ = 2.7–20.1°
c = 11.4739 (13) Å	µ = 0.25 mm⁻¹
β = 97.198 (1)°	T = 298 K
V = 2293.5 (4) Å³	Block, yellow
Z = 4	0.43 × 0.35 × 0.31 mm

Data collection top

Bruker SMART APEX CCD area-etector diffractometer	4043 independent reflections
Radiation source: fine-focus sealed tube	1764 reflections with I > 2σ(I)
Graphite monochromator	R_int = 0.125
φ and ω scans	θ_max = 25.0°, θ_min = 2.7°
Absorption correction: multi-scan (SADABS; Sheldrick, 1996)	h = −12→12
T_min = 0.901, T_max = 0.927	k = −20→23
11618 measured reflections	l = −13→11

Refinement top

Refinement on F²	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F² > 2σ(F²)] = 0.060	Hydrogen site location: inferred from neighbouring sites
wR(F²) = 0.197	H-atom parameters constrained
S = 1.05	w = 1/[σ²(F_o²) + (0.0425P)² + 0.9182P] where P = (F_o² + 2F_c²)/3
4043 reflections	(Δ/σ)_max < 0.001
271 parameters	Δρ_max = 0.27 e Å⁻³
0 restraints	Δρ_min = −0.24 e Å⁻³

Crystal data top

C₂₆H₂₀N₂S₂	V = 2293.5 (4) Å³
M_r = 424.56	Z = 4
Monoclinic, P2₁/n	Mo Kα radiation
a = 10.2421 (11) Å	µ = 0.25 mm⁻¹
b = 19.672 (2) Å	T = 298 K
c = 11.4739 (13) Å	0.43 × 0.35 × 0.31 mm
β = 97.198 (1)°

Data collection top

Bruker SMART APEX CCD area-etector diffractometer	4043 independent reflections
Absorption correction: multi-scan (SADABS; Sheldrick, 1996)	1764 reflections with I > 2σ(I)
T_min = 0.901, T_max = 0.927	R_int = 0.125
11618 measured reflections

Refinement top

R[F² > 2σ(F²)] = 0.060	0 restraints
wR(F²) = 0.197	H-atom parameters constrained
S = 1.05	Δρ_max = 0.27 e Å⁻³
4043 reflections	Δρ_min = −0.24 e Å⁻³
271 parameters

Special details top

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 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 > 2sigma(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 (Å²) top

	x	y	z	U_iso*/U_eq
N1	0.3113 (4)	0.0052 (2)	0.2975 (3)	0.0710 (11)
N2	−0.1878 (4)	0.2777 (2)	0.1398 (3)	0.0691 (11)
S1	0.03931 (13)	0.20245 (7)	0.22438 (11)	0.0799 (5)
S2	0.13336 (13)	0.11360 (7)	0.27203 (11)	0.0730 (5)
C1	−0.0581 (4)	0.1836 (2)	0.0887 (4)	0.0634 (13)
C2	−0.0300 (5)	0.1322 (3)	0.0121 (4)	0.0793 (15)
H2	0.0438	0.1049	0.0310	0.095*
C3	−0.1116 (6)	0.1215 (3)	−0.0918 (5)	0.0934 (18)
H3	−0.0924	0.0871	−0.1427	0.112*
C4	−0.2203 (6)	0.1613 (3)	−0.1198 (5)	0.1015 (19)
H4	−0.2759	0.1534	−0.1890	0.122*
C5	−0.2480 (5)	0.2136 (3)	−0.0457 (4)	0.0833 (16)
H5	−0.3215	0.2409	−0.0659	0.100*
C6	−0.1665 (5)	0.2255 (3)	0.0588 (4)	0.0660 (13)
C7	−0.2390 (5)	0.3338 (3)	0.1026 (4)	0.0725 (14)
H7	−0.2612	0.3392	0.0220	0.087*
C8	−0.2650 (5)	0.3901 (3)	0.1794 (5)	0.0715 (14)
C9	−0.3206 (5)	0.4488 (3)	0.1287 (6)	0.0952 (18)
H9	−0.3408	0.4520	0.0476	0.114*
C10	−0.3455 (6)	0.5022 (4)	0.1994 (8)	0.120 (2)
H10	−0.3823	0.5418	0.1654	0.144*
C11	−0.3178 (7)	0.4986 (3)	0.3175 (8)	0.111 (2)
H11	−0.3384	0.5349	0.3639	0.133*
C12	−0.2592 (6)	0.4413 (3)	0.3693 (6)	0.1038 (19)
H12	−0.2372	0.4391	0.4503	0.125*
C13	−0.2333 (6)	0.3868 (3)	0.2991 (5)	0.0928 (17)
H13	−0.1942	0.3478	0.3333	0.111*
C14	0.2829 (5)	0.1152 (2)	0.2100 (4)	0.0651 (13)
C15	0.3270 (6)	0.1690 (3)	0.1459 (5)	0.0845 (16)
H15	0.2761	0.2082	0.1344	0.101*
C16	0.4451 (7)	0.1652 (3)	0.0993 (6)	0.115 (2)
H16	0.4732	0.2015	0.0569	0.138*
C17	0.5212 (6)	0.1068 (4)	0.1163 (7)	0.128 (3)
H17	0.6001	0.1035	0.0843	0.153*
C18	0.4787 (6)	0.0531 (3)	0.1814 (6)	0.108 (2)
H18	0.5296	0.0139	0.1924	0.130*
C19	0.3620 (5)	0.0573 (3)	0.2299 (4)	0.0732 (14)
C20	0.3876 (5)	−0.0331 (3)	0.3620 (5)	0.0722 (14)
H20	0.4779	−0.0266	0.3646	0.087*
C21	0.3406 (6)	−0.0872 (2)	0.4330 (4)	0.0667 (13)
C22	0.2066 (6)	−0.1007 (3)	0.4311 (5)	0.0795 (15)
H22	0.1453	−0.0757	0.3819	0.095*
C23	0.1646 (6)	−0.1507 (3)	0.5016 (6)	0.0992 (18)
H23	0.0752	−0.1598	0.4990	0.119*
C24	0.2532 (9)	−0.1871 (3)	0.5753 (6)	0.104 (2)
H24	0.2237	−0.2198	0.6243	0.125*
C25	0.3835 (9)	−0.1760 (3)	0.5775 (6)	0.111 (2)
H25	0.4436	−0.2019	0.6263	0.134*
C26	0.4280 (6)	−0.1253 (3)	0.5061 (5)	0.0976 (18)
H26	0.5178	−0.1175	0.5083	0.117*

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
N1	0.088 (3)	0.058 (3)	0.067 (3)	−0.001 (2)	0.009 (2)	0.006 (2)
N2	0.087 (3)	0.063 (3)	0.056 (2)	0.008 (2)	0.001 (2)	0.007 (2)
S1	0.0979 (10)	0.0781 (10)	0.0572 (8)	0.0153 (7)	−0.0157 (7)	−0.0105 (7)
S2	0.0825 (9)	0.0791 (9)	0.0549 (7)	0.0065 (7)	−0.0016 (6)	0.0091 (7)
C1	0.074 (3)	0.065 (3)	0.048 (3)	0.000 (3)	−0.005 (2)	0.005 (3)
C2	0.097 (4)	0.081 (4)	0.058 (3)	0.014 (3)	0.000 (3)	−0.006 (3)
C3	0.128 (5)	0.089 (4)	0.057 (3)	0.015 (4)	−0.011 (3)	−0.017 (3)
C4	0.128 (5)	0.105 (5)	0.061 (3)	0.013 (4)	−0.028 (3)	−0.016 (4)
C5	0.096 (4)	0.086 (4)	0.061 (3)	0.013 (3)	−0.017 (3)	0.005 (3)
C6	0.081 (3)	0.069 (3)	0.046 (3)	0.001 (3)	0.001 (2)	0.000 (3)
C7	0.083 (3)	0.076 (4)	0.057 (3)	0.001 (3)	0.005 (3)	0.011 (3)
C8	0.083 (3)	0.061 (3)	0.071 (4)	0.005 (3)	0.013 (3)	0.008 (3)
C9	0.109 (4)	0.078 (4)	0.096 (4)	0.022 (3)	0.006 (4)	0.009 (4)
C10	0.133 (6)	0.087 (5)	0.139 (7)	0.033 (4)	0.020 (5)	0.005 (5)
C11	0.131 (5)	0.073 (5)	0.137 (7)	0.008 (4)	0.052 (5)	−0.013 (5)
C12	0.153 (6)	0.079 (4)	0.082 (4)	−0.015 (4)	0.026 (4)	−0.002 (4)
C13	0.140 (5)	0.059 (4)	0.083 (4)	0.007 (3)	0.028 (4)	0.009 (3)
C14	0.071 (3)	0.062 (3)	0.060 (3)	0.000 (3)	−0.002 (2)	0.004 (3)
C15	0.091 (4)	0.072 (4)	0.089 (4)	0.004 (3)	0.004 (3)	0.022 (3)
C16	0.109 (5)	0.103 (5)	0.136 (6)	0.004 (4)	0.027 (5)	0.057 (5)
C17	0.104 (5)	0.135 (6)	0.155 (7)	0.014 (5)	0.053 (5)	0.059 (6)
C18	0.104 (5)	0.093 (5)	0.132 (6)	0.020 (4)	0.038 (4)	0.038 (4)
C19	0.071 (3)	0.075 (4)	0.072 (3)	0.000 (3)	0.003 (3)	0.008 (3)
C20	0.080 (3)	0.063 (3)	0.074 (3)	0.006 (3)	0.011 (3)	0.001 (3)
C21	0.090 (4)	0.053 (3)	0.057 (3)	0.008 (3)	0.008 (3)	−0.003 (3)
C22	0.099 (4)	0.058 (3)	0.082 (4)	0.003 (3)	0.013 (3)	0.006 (3)
C23	0.118 (5)	0.076 (4)	0.104 (5)	−0.013 (4)	0.019 (4)	0.005 (4)
C24	0.171 (7)	0.054 (4)	0.089 (5)	0.002 (4)	0.021 (5)	0.008 (3)
C25	0.157 (7)	0.075 (4)	0.101 (5)	0.042 (5)	0.008 (5)	0.020 (4)
C26	0.115 (5)	0.082 (4)	0.095 (4)	0.024 (4)	0.011 (4)	0.019 (4)

Geometric parameters (Å, º) top

N1—C20	1.258 (6)	C12—C13	1.386 (7)
N1—C19	1.423 (6)	C12—H12	0.9300
N2—C7	1.272 (5)	C13—H13	0.9300
N2—C6	1.420 (6)	C14—C15	1.395 (7)
S1—C1	1.779 (4)	C14—C19	1.400 (6)
S1—S2	2.0371 (18)	C15—C16	1.385 (7)
S2—C14	1.768 (5)	C15—H15	0.9300
C1—C6	1.391 (6)	C16—C17	1.389 (8)
C1—C2	1.394 (6)	C16—H16	0.9300
C2—C3	1.383 (7)	C17—C18	1.394 (8)
C2—H2	0.9300	C17—H17	0.9300
C3—C4	1.367 (7)	C18—C19	1.383 (7)
C3—H3	0.9300	C18—H18	0.9300
C4—C5	1.386 (7)	C20—C21	1.458 (7)
C4—H4	0.9300	C20—H20	0.9300
C5—C6	1.393 (6)	C21—C26	1.371 (7)
C5—H5	0.9300	C21—C22	1.395 (7)
C7—C8	1.461 (7)	C22—C23	1.377 (7)
C7—H7	0.9300	C22—H22	0.9300
C8—C13	1.372 (7)	C23—C24	1.363 (8)
C8—C9	1.383 (7)	C23—H23	0.9300
C9—C10	1.370 (8)	C24—C25	1.349 (8)
C9—H9	0.9300	C24—H24	0.9300
C10—C11	1.351 (9)	C25—C26	1.402 (8)
C10—H10	0.9300	C25—H25	0.9300
C11—C12	1.377 (8)	C26—H26	0.9300
C11—H11	0.9300

C20—N1—C19	120.7 (5)	C8—C13—H13	119.8
C7—N2—C6	119.9 (4)	C12—C13—H13	119.8
C1—S1—S2	104.50 (17)	C15—C14—C19	119.0 (5)
C14—S2—S1	106.31 (17)	C15—C14—S2	125.4 (4)
C6—C1—C2	119.7 (4)	C19—C14—S2	115.6 (4)
C6—C1—S1	115.8 (4)	C16—C15—C14	121.2 (5)
C2—C1—S1	124.5 (4)	C16—C15—H15	119.4
C3—C2—C1	120.3 (5)	C14—C15—H15	119.4
C3—C2—H2	119.9	C15—C16—C17	119.6 (6)
C1—C2—H2	119.9	C15—C16—H16	120.2
C4—C3—C2	120.1 (5)	C17—C16—H16	120.2
C4—C3—H3	119.9	C16—C17—C18	119.6 (6)
C2—C3—H3	119.9	C16—C17—H17	120.2
C3—C4—C5	120.3 (5)	C18—C17—H17	120.2
C3—C4—H4	119.8	C19—C18—C17	120.9 (6)
C5—C4—H4	119.8	C19—C18—H18	119.5
C4—C5—C6	120.4 (5)	C17—C18—H18	119.5
C4—C5—H5	119.8	C18—C19—C14	119.7 (5)
C6—C5—H5	119.8	C18—C19—N1	124.7 (5)
C1—C6—C5	119.1 (5)	C14—C19—N1	115.6 (5)
C1—C6—N2	116.8 (4)	N1—C20—C21	122.8 (5)
C5—C6—N2	124.1 (5)	N1—C20—H20	118.6
N2—C7—C8	123.6 (5)	C21—C20—H20	118.6
N2—C7—H7	118.2	C26—C21—C22	118.1 (5)
C8—C7—H7	118.2	C26—C21—C20	120.3 (5)
C13—C8—C9	119.6 (5)	C22—C21—C20	121.6 (5)
C13—C8—C7	122.0 (5)	C23—C22—C21	120.4 (5)
C9—C8—C7	118.4 (5)	C23—C22—H22	119.8
C10—C9—C8	119.2 (6)	C21—C22—H22	119.8
C10—C9—H9	120.4	C24—C23—C22	120.5 (6)
C8—C9—H9	120.4	C24—C23—H23	119.8
C11—C10—C9	121.6 (7)	C22—C23—H23	119.8
C11—C10—H10	119.2	C25—C24—C23	120.4 (6)
C9—C10—H10	119.2	C25—C24—H24	119.8
C10—C11—C12	120.0 (6)	C23—C24—H24	119.8
C10—C11—H11	120.0	C24—C25—C26	119.8 (6)
C12—C11—H11	120.0	C24—C25—H25	120.1
C11—C12—C13	119.2 (6)	C26—C25—H25	120.1
C11—C12—H12	120.4	C21—C26—C25	120.7 (6)
C13—C12—H12	120.4	C21—C26—H26	119.6
C8—C13—C12	120.4 (5)	C25—C26—H26	119.6

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
C5—H5···S1ⁱ	0.93	2.86	3.604 (5)	137

Symmetry code: (i) x−1/2, −y+1/2, z−1/2.

Experimental details

Crystal data
Chemical formula	C₂₆H₂₀N₂S₂
M_r	424.56
Crystal system, space group	Monoclinic, P2₁/n
Temperature (K)	298
a, b, c (Å)	10.2421 (11), 19.672 (2), 11.4739 (13)
β (°)	97.198 (1)
V (Å³)	2293.5 (4)
Z	4
Radiation type	Mo Kα
µ (mm⁻¹)	0.25
Crystal size (mm)	0.43 × 0.35 × 0.31

Data collection
Diffractometer	Bruker SMART APEX CCD area-etector
Absorption correction	Multi-scan (SADABS; Sheldrick, 1996)
T_min, T_max	0.901, 0.927
No. of measured, independent and observed [I > 2σ(I)] reflections	11618, 4043, 1764
R_int	0.125
(sin θ/λ)_max (Å⁻¹)	0.595

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.060, 0.197, 1.05
No. of reflections	4043
No. of parameters	271
H-atom treatment	H-atom parameters constrained
Δρ_max, Δρ_min (e Å⁻³)	0.27, −0.24

Computer programs: SMART (Bruker, 2007), SAINT (Bruker, 2007), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), SHELXTL (Sheldrick, 2008).

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
C5—H5···S1ⁱ	0.93	2.86	3.604 (5)	137.4

Symmetry code: (i) x−1/2, −y+1/2, z−1/2.

Acknowledgements

The authors acknowledge financial support by the University Student Science and Technology Culture Foundation of Liaocheng University (grant No. SRT11056HX2) and Liaocheng University (grant No. X09012).

References

Bai, Y., Dang, D.-B., Duan, C.-Y., Song, Y. & Meng, Q.-J. (2005). Inorg. Chem. 44, 5972–5974. Web of Science CSD CrossRef PubMed CAS Google Scholar
Bruker (2007). SMART and SAINT. Bruker AXS Inc., Madison, Wisconsin, USA. Google Scholar
He, Q.-P., Dai, L. & Tan, B. (2011). Acta Cryst. E67, o3240. Web of Science CSD CrossRef IUCr Journals Google Scholar
Sheldrick, G. M. (1996). SADABS. University of Göttingen, Germany. Google Scholar
Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122. Web of Science CrossRef CAS IUCr Journals Google Scholar
Wang, Z., Jian, F., Duan, C., Bai, Z. & You, X. (1998). Acta Cryst. C54, 1927–1929. Web of Science CSD CrossRef CAS IUCr Journals Google Scholar