catena-Poly[[tri-n-butyl­tin(IV)]-μ-2-thio­phene­acetato]

Wang, H.; Yin, H.; Sun, Y.

doi:10.1107/S1600536807063623

metal-organic compounds

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ISSN: 2056-9890

Volume 64| Part 1| January 2008| Page m81

https://doi.org/10.1107/S1600536807063623

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catena-Poly[[tri-n-butyltin(IV)]-μ-2-thiopheneacetato]

Hongyun Wang,^a Handong Yin ^a ^* and Yuying Sun ^b

^aCollege of Chemistry and Chemical Engineering, Liaocheng University, Shandong 252059, People's Republic of China, and ^bAnalytical and Testing Center of Beihua University, Beihua, 132013, People's Republic of China
^*Correspondence e-mail: handongyin@163.com

(Received 5 November 2007; accepted 26 November 2007; online 6 December 2007)

The title compound, [Sn(C₄H₉)₃(C₆H₅O₂S)]_n, possesses an infinite chain structure. The SnO₂C₃ centre has a distorted trigonal-bipyramidal geometry (τ = 0.145) with the O atoms in the axial positions. Atoms of the thiophene group S1 and C4 are disordered over two sites The S atom and one C atom, with attached H atom, of the thiophene ring are disordered over two positions; the site occupancy factors are ca 0.7 and 0.3.

Related literature

For related literature see: Addison et al. (1984 ); Ma et al. (2006 ).

Experimental

Crystal data

[Sn(C₄H₉)₃(C₆H₅O₂S)]
M_r = 431.19
Monoclinic, P 2₁ /c
a = 12.7657 (15) Å
b = 10.6970 (13) Å
c = 16.328 (2) Å
β = 100.435 (2)°
V = 2192.8 (5) Å³
Z = 4
Mo Kα radiation
μ = 1.26 mm⁻¹
T = 298 (2) K
0.46 × 0.21 × 0.12 mm

Data collection

Bruker SMART CCD area-detector diffractometer
Absorption correction: multi-scan (SADABS; Sheldrick, 1996 ) T_min = 0.594, T_max = 0.863
8428 measured reflections
3715 independent reflections
2104 reflections with I > 2σ(I)
R_int = 0.042

Refinement

R[F² > 2σ(F²)] = 0.060
wR(F²) = 0.197
S = 1.10
3715 reflections
200 parameters
483 restraints
H-atom parameters constrained
Δρ_max = 0.96 e Å⁻³
Δρ_min = −0.51 e Å⁻³

Data collection: SMART (Siemens, 1996 ); cell refinement: SAINT (Siemens, 1996); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 1997a ); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997a); molecular graphics: SHELXTL (Sheldrick, 1997b ); software used to prepare material for publication: SHELXTL.

Supporting information

Crystal structure: contains datablocks I, global. DOI: https://doi.org/10.1107/S1600536807063623/bv2084sup1.cif

Structure factors: contains datablock I. DOI: https://doi.org/10.1107/S1600536807063623/bv2084Isup2.hkl

checkCIF report

Comment top

The title compound, (I) (Fig. 1), possesses an infinite one-dimensional chain structure arising from Sn—O bridges to the ligand. The Sn1—O1 distances of 2.183 (6) Å and Sn1—O2A [symmetry code: -x + 2,y - 1/2,-z + 1/2] distance 2.482 (7) Å, are similar to those reported for other organotin carboxylates (Ma et al., 2006). The Sn atom has distorted trigonal-bipyramidal geometry[τ = 0.145; Addison et al.,, 1984], with atoms O1 and O2A in axial positions [O1—Sn1—O2A = 171.3 (2) °] and the C atoms of the three butyl groups in equatorial positions. The sum of the equatorial C—Sn—C angles is 358.6 °, indicating approximate coplanarity for these atoms.

Related literature top

For related literature see: Addison et al. (1984); Ma et al. (2006)

Experimental top

The reaction was carried out under nitrogen atmosphere. 2-Thiopheneacetic acid (1 mmol) and sodium ethoxide (1.2 mmol) were added to the solution of benzene(30 ml) in a Schlenk flask and stirred for 0.5 h. Tri-n-butyltin chloride (1 mmol) was then added to the reactor and the reaction mixture was stirred for 12 h at 313 K. The resulting clear solution was evaporated under vacuum. The product was crystallized from a mixture of dichloromethane/methanol (1:1).(yield 80%; m.p. 457 K). Analysis calculated (%) for C₁₈H₃₂O₂SSn (Mr = 431.19): C, 50.14; H, 7.48. found: C, 50.06; H, 7.53.

Structure description top

For related literature see: Addison et al. (1984); Ma et al. (2006)

Computing details top

Data collection: SMART (Siemens, 1996); cell refinement: SMART (Siemens, 1996); data reduction: SAINT (Siemens, 1996); program(s) used to solve structure: SHELXS97 (Sheldrick, 1997a); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997a); molecular graphics: SHELXTL (Sheldrick, 1997b); software used to prepare material for publication: SHELXTL (Sheldrick, 1997b).

Figures top

	Fig. 1. The molecular structure of (I), showing 50% probability displacement ellipsoids and the atom-numbering scheme. H atoms have been omitted for clarity.
	Fig. 2. The one-dimensional infinite chain structure of (I), H atoms have been omitted for clarity.

catena-Poly[[tri-n-butyltin(IV)]-µ-2-thiopheneacetato] top

Crystal data top

[Sn(C₄H₉)₃(C₆H₅O₂S)]	F(000) = 888
M_r = 431.19	D_x = 1.306 Mg m⁻³
Monoclinic, P2₁/c	Mo Kα radiation, λ = 0.71073 Å
a = 12.7657 (15) Å	Cell parameters from 2306 reflections
b = 10.6970 (13) Å	θ = 2.3–22.1°
c = 16.328 (2) Å	µ = 1.27 mm⁻¹
β = 100.435 (2)°	T = 298 K
V = 2192.8 (5) Å³	Block, colourless
Z = 4	0.46 × 0.21 × 0.12 mm

Data collection top

Bruker SMART CCD area-detector diffractometer	3715 independent reflections
Radiation source: fine-focus sealed tube	2104 reflections with I > 2σ(I)
Graphite monochromator	R_int = 0.042
phi and ω scans	θ_max = 25.0°, θ_min = 2.3°
Absorption correction: multi-scan (SADABS; Sheldrick, 1996)	h = −9→15
T_min = 0.594, T_max = 0.863	k = −12→12
8428 measured reflections	l = −19→18

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 = 1.10	w = 1/[σ²(F_o²) + (0.080P)² + 4.0018P] where P = (F_o² + 2F_c²)/3
3715 reflections	(Δ/σ)_max < 0.001
200 parameters	Δρ_max = 0.96 e Å⁻³
483 restraints	Δρ_min = −0.51 e Å⁻³

Crystal data top

[Sn(C₄H₉)₃(C₆H₅O₂S)]	V = 2192.8 (5) Å³
M_r = 431.19	Z = 4
Monoclinic, P2₁/c	Mo Kα radiation
a = 12.7657 (15) Å	µ = 1.27 mm⁻¹
b = 10.6970 (13) Å	T = 298 K
c = 16.328 (2) Å	0.46 × 0.21 × 0.12 mm
β = 100.435 (2)°

Data collection top

Bruker SMART CCD area-detector diffractometer	3715 independent reflections
Absorption correction: multi-scan (SADABS; Sheldrick, 1996)	2104 reflections with I > 2σ(I)
T_min = 0.594, T_max = 0.863	R_int = 0.042
8428 measured reflections

Refinement top

R[F² > 2σ(F²)] = 0.060	483 restraints
wR(F²) = 0.197	H-atom parameters constrained
S = 1.10	Δρ_max = 0.96 e Å⁻³
3715 reflections	Δρ_min = −0.51 e Å⁻³
200 parameters

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å²) top

	x	y	z	U_iso*/U_eq	Occ. (<1)
Sn1	0.99480 (5)	0.76650 (6)	0.29167 (4)	0.0663 (3)
O1	0.9550 (5)	0.9174 (5)	0.3707 (4)	0.0663 (3)
O2	0.9708 (5)	1.0734 (6)	0.2834 (5)	0.0845 (19)
S1	0.7850 (4)	0.9564 (5)	0.4888 (4)	0.1199 (19)	0.729 (11)
C4'	0.7695 (14)	1.001 (5)	0.494 (2)	0.1199 (19)	0.271 (11)
H4'	0.8167	0.9802	0.5426	0.144*	0.271 (11)
C1	0.9465 (8)	1.0331 (9)	0.3486 (8)	0.085 (2)
C2	0.9043 (8)	1.1152 (9)	0.4098 (7)	0.091 (3)
H2A	0.8984	1.2001	0.3886	0.109*
H2B	0.9548	1.1157	0.4619	0.109*
C3	0.7953 (6)	1.0734 (9)	0.4269 (7)	0.096 (3)
C4	0.6941 (9)	1.094 (2)	0.3728 (9)	0.120 (3)	0.729 (11)
H4	0.6844	1.1329	0.3210	0.144*	0.729 (11)
S1'	0.6898 (9)	1.1447 (13)	0.3827 (10)	0.120 (3)	0.271 (11)
C5	0.6121 (8)	1.0451 (13)	0.4115 (9)	0.141 (4)
H5	0.5398	1.0630	0.3972	0.169*
C6	0.6597 (8)	0.9649 (12)	0.4754 (9)	0.132 (4)
H6	0.6200	0.9197	0.5077	0.158*
C7	0.9691 (9)	0.6340 (11)	0.3839 (9)	0.111 (3)
H7A	1.0023	0.5550	0.3745	0.133*
H7B	1.0010	0.6640	0.4388	0.133*
C8	0.8496 (10)	0.6152 (15)	0.3792 (10)	0.152 (4)
H8A	0.8180	0.6950	0.3891	0.182*
H8B	0.8186	0.5890	0.3231	0.182*
C9	0.8204 (12)	0.5212 (15)	0.4396 (10)	0.174 (6)
H9A	0.8505	0.5469	0.4959	0.209*
H9B	0.8508	0.4407	0.4296	0.209*
C10	0.7012 (12)	0.5082 (19)	0.4313 (12)	0.219 (9)
H10A	0.6792	0.4285	0.4072	0.329*
H10B	0.6666	0.5736	0.3961	0.329*
H10C	0.6819	0.5144	0.4853	0.329*
C11	0.8709 (9)	0.8019 (12)	0.1866 (9)	0.117 (3)
H11A	0.8916	0.8710	0.1545	0.140*
H11B	0.8613	0.7287	0.1509	0.140*
C12	0.7657 (10)	0.8333 (16)	0.2144 (9)	0.155 (4)
H12A	0.7578	0.7793	0.2606	0.186*
H12B	0.7691	0.9188	0.2345	0.186*
C13	0.6690 (12)	0.820 (2)	0.1477 (11)	0.207 (7)
H13A	0.6709	0.7394	0.1202	0.249*
H13B	0.6685	0.8848	0.1063	0.249*
C14	0.5677 (14)	0.829 (3)	0.1860 (15)	0.252 (10)
H14A	0.5511	0.7479	0.2059	0.379*
H14B	0.5095	0.8571	0.1445	0.379*
H14C	0.5793	0.8868	0.2316	0.379*
C15	1.1571 (7)	0.8270 (10)	0.2960 (8)	0.096 (3)
H15A	1.1707	0.8312	0.2395	0.116*
H15B	1.1648	0.9107	0.3190	0.116*
C16	1.2406 (7)	0.7433 (11)	0.3470 (10)	0.125 (4)
H16A	1.2330	0.6590	0.3249	0.150*
H16B	1.2292	0.7408	0.4041	0.150*
C17	1.3543 (8)	0.7906 (14)	0.3454 (11)	0.146 (5)
H17A	1.3663	0.7918	0.2885	0.175*
H17B	1.3619	0.8753	0.3668	0.175*
C18	1.4368 (12)	0.7064 (18)	0.3981 (14)	0.209 (8)
H18A	1.4031	0.6308	0.4115	0.313*
H18B	1.4672	0.7491	0.4485	0.313*
H18C	1.4919	0.6865	0.3673	0.313*

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
Sn1	0.0755 (5)	0.0549 (4)	0.0733 (6)	0.0017 (3)	0.0260 (3)	0.0032 (3)
O1	0.0755 (5)	0.0549 (4)	0.0733 (6)	0.0017 (3)	0.0260 (3)	0.0032 (3)
O2	0.107 (4)	0.061 (4)	0.094 (5)	−0.002 (3)	0.042 (4)	0.012 (3)
S1	0.123 (3)	0.103 (3)	0.144 (4)	0.007 (2)	0.054 (3)	0.020 (3)
C4'	0.123 (3)	0.103 (3)	0.144 (4)	0.007 (2)	0.054 (3)	0.020 (3)
C1	0.092 (5)	0.060 (4)	0.111 (6)	0.001 (4)	0.037 (5)	0.001 (5)
C2	0.113 (6)	0.062 (5)	0.107 (6)	0.007 (5)	0.046 (5)	0.001 (5)
C3	0.100 (5)	0.086 (5)	0.115 (6)	0.016 (5)	0.050 (5)	−0.003 (5)
C4	0.121 (5)	0.106 (6)	0.145 (5)	0.026 (4)	0.053 (4)	0.010 (5)
S1'	0.121 (5)	0.106 (6)	0.145 (5)	0.026 (4)	0.053 (4)	0.010 (5)
C5	0.121 (7)	0.148 (8)	0.163 (8)	0.017 (7)	0.049 (7)	0.004 (7)
C6	0.132 (7)	0.128 (7)	0.150 (8)	−0.001 (6)	0.067 (6)	0.008 (7)
C7	0.131 (7)	0.089 (6)	0.122 (8)	0.018 (6)	0.047 (6)	0.013 (6)
C8	0.162 (8)	0.135 (8)	0.159 (9)	0.005 (7)	0.033 (8)	0.024 (7)
C9	0.174 (12)	0.158 (11)	0.192 (12)	0.009 (10)	0.034 (11)	0.020 (11)
C10	0.163 (16)	0.229 (19)	0.25 (2)	−0.001 (14)	−0.001 (15)	0.042 (18)
C11	0.113 (6)	0.102 (6)	0.137 (7)	0.010 (5)	0.024 (6)	−0.005 (6)
C12	0.154 (8)	0.141 (8)	0.162 (8)	0.005 (7)	0.007 (7)	0.015 (7)
C13	0.176 (12)	0.204 (12)	0.232 (13)	0.012 (12)	0.013 (12)	0.016 (12)
C14	0.198 (18)	0.31 (2)	0.27 (2)	0.017 (19)	0.083 (17)	−0.01 (2)
C15	0.086 (6)	0.089 (6)	0.121 (7)	−0.008 (5)	0.036 (5)	−0.008 (5)
C16	0.083 (7)	0.128 (9)	0.160 (11)	0.002 (6)	0.009 (7)	−0.027 (8)
C17	0.085 (8)	0.160 (10)	0.194 (12)	0.001 (7)	0.028 (8)	−0.044 (10)
C18	0.124 (13)	0.225 (17)	0.27 (2)	0.019 (13)	0.006 (14)	−0.028 (17)

Geometric parameters (Å, º) top

Sn1—C7	2.136 (11)	C9—C10	1.510 (9)
Sn1—C11	2.147 (13)	C9—H9A	0.9700
Sn1—C15	2.159 (10)	C9—H9B	0.9700
Sn1—O1	2.183 (6)	C10—H10A	0.9600
Sn1—O2ⁱ	2.482 (7)	C10—H10B	0.9600
O1—C1	1.288 (11)	C10—H10C	0.9600
O2—C1	1.239 (12)	C11—C12	1.531 (9)
O2—Sn1ⁱⁱ	2.482 (7)	C11—H11A	0.9700
S1—C6	1.577 (11)	C11—H11B	0.9700
S1—C3	1.630 (9)	C12—C13	1.497 (10)
C4'—C3	1.432 (9)	C12—H12A	0.9700
C4'—C6	1.432 (9)	C12—H12B	0.9700
C4'—H4'	0.9300	C13—C14	1.539 (10)
C1—C2	1.502 (14)	C13—H13A	0.9700
C2—C3	1.534 (8)	C13—H13B	0.9700
C2—H2A	0.9700	C14—H14A	0.9600
C2—H2B	0.9700	C14—H14B	0.9600
C3—C4	1.443 (9)	C14—H14C	0.9600
C3—S1'	1.601 (13)	C15—C16	1.519 (9)
C4—C5	1.418 (9)	C15—H15A	0.9700
C4—H4	0.9300	C15—H15B	0.9700
S1'—C5	1.585 (14)	C16—C17	1.541 (9)
C5—C6	1.400 (9)	C16—H16A	0.9700
C5—H5	0.9300	C16—H16B	0.9700
C6—H6	0.9300	C17—C18	1.527 (10)
C7—C8	1.526 (9)	C17—H17A	0.9700
C7—H7A	0.9700	C17—H17B	0.9700
C7—H7B	0.9700	C18—H18A	0.9600
C8—C9	1.502 (9)	C18—H18B	0.9600
C8—H8A	0.9700	C18—H18C	0.9600
C8—H8B	0.9700

C7—Sn1—C11	119.7 (5)	H8A—C8—H8B	107.5
C7—Sn1—C15	116.4 (4)	C8—C9—C10	111.6 (11)
C11—Sn1—C15	122.5 (5)	C8—C9—H9A	109.3
C7—Sn1—O1	89.5 (4)	C10—C9—H9A	109.3
C11—Sn1—O1	97.2 (4)	C8—C9—H9B	109.3
C15—Sn1—O1	94.8 (3)	C10—C9—H9B	109.3
C7—Sn1—O2ⁱ	81.9 (4)	H9A—C9—H9B	108.0
C11—Sn1—O2ⁱ	85.5 (4)	C9—C10—H10A	109.5
C15—Sn1—O2ⁱ	90.6 (3)	C9—C10—H10B	109.5
O1—Sn1—O2ⁱ	171.3 (2)	H10A—C10—H10B	109.5
C1—O1—Sn1	124.2 (7)	C9—C10—H10C	109.5
C1—O2—Sn1ⁱⁱ	144.0 (7)	H10A—C10—H10C	109.5
C6—S1—C3	93.6 (5)	H10B—C10—H10C	109.5
C3—C4'—C6	109.4 (8)	C12—C11—Sn1	111.1 (9)
C3—C4'—H4'	125.3	C12—C11—H11A	109.4
C6—C4'—H4'	125.3	Sn1—C11—H11A	109.4
O2—C1—O1	123.6 (10)	C12—C11—H11B	109.4
O2—C1—C2	122.9 (9)	Sn1—C11—H11B	109.4
O1—C1—C2	113.5 (10)	H11A—C11—H11B	108.0
C1—C2—C3	113.4 (9)	C13—C12—C11	114.4 (11)
C1—C2—H2A	108.9	C13—C12—H12A	108.6
C3—C2—H2A	108.9	C11—C12—H12A	108.6
C1—C2—H2B	108.9	C13—C12—H12B	108.6
C3—C2—H2B	108.9	C11—C12—H12B	108.6
H2A—C2—H2B	107.7	H12A—C12—H12B	107.6
C4'—C3—C4	104.3 (7)	C12—C13—C14	109.9 (12)
C4'—C3—C2	129.8 (9)	C12—C13—H13A	109.7
C4—C3—C2	125.8 (9)	C14—C13—H13A	109.7
C4'—C3—S1'	108.2 (13)	C12—C13—H13B	109.7
C4—C3—S1'	20.8 (11)	C14—C13—H13B	109.7
C2—C3—S1'	119.7 (8)	H13A—C13—H13B	108.2
C4'—C3—S1	18 (3)	C13—C14—H14A	109.5
C4—C3—S1	109.4 (7)	C13—C14—H14B	109.5
C2—C3—S1	121.0 (7)	H14A—C14—H14B	109.5
S1'—C3—S1	119.3 (7)	C13—C14—H14C	109.5
C5—C4—C3	108.8 (7)	H14A—C14—H14C	109.5
C5—C4—H4	125.6	H14B—C14—H14C	109.5
C3—C4—H4	125.6	C16—C15—Sn1	114.6 (7)
C5—S1'—C3	93.8 (8)	C16—C15—H15A	108.6
C6—C5—C4	107.6 (7)	Sn1—C15—H15A	108.6
C6—C5—S1'	115.0 (8)	C16—C15—H15B	108.6
C4—C5—S1'	21.0 (11)	Sn1—C15—H15B	108.6
C6—C5—H5	126.2	H15A—C15—H15B	107.6
C4—C5—H5	126.2	C15—C16—C17	111.5 (9)
S1'—C5—H5	115.6	C15—C16—H16A	109.3
C5—C6—C4'	105.8 (9)	C17—C16—H16A	109.3
C5—C6—S1	115.6 (7)	C15—C16—H16B	109.3
C4'—C6—S1	19 (3)	C17—C16—H16B	109.3
C5—C6—H6	122.2	H16A—C16—H16B	108.0
C4'—C6—H6	129.0	C18—C17—C16	110.7 (11)
S1—C6—H6	122.2	C18—C17—H17A	109.5
C8—C7—Sn1	109.3 (8)	C16—C17—H17A	109.5
C8—C7—H7A	109.8	C18—C17—H17B	109.5
Sn1—C7—H7A	109.8	C16—C17—H17B	109.5
C8—C7—H7B	109.8	H17A—C17—H17B	108.1
Sn1—C7—H7B	109.8	C17—C18—H18A	109.5
H7A—C7—H7B	108.3	C17—C18—H18B	109.5
C9—C8—C7	114.8 (10)	H18A—C18—H18B	109.5
C9—C8—H8A	108.6	C17—C18—H18C	109.5
C7—C8—H8A	108.6	H18A—C18—H18C	109.5
C9—C8—H8B	108.6	H18B—C18—H18C	109.5
C7—C8—H8B	108.6

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

Experimental details

Crystal data
Chemical formula	[Sn(C₄H₉)₃(C₆H₅O₂S)]
M_r	431.19
Crystal system, space group	Monoclinic, P2₁/c
Temperature (K)	298
a, b, c (Å)	12.7657 (15), 10.6970 (13), 16.328 (2)
β (°)	100.435 (2)
V (Å³)	2192.8 (5)
Z	4
Radiation type	Mo Kα
µ (mm⁻¹)	1.27
Crystal size (mm)	0.46 × 0.21 × 0.12

Data collection
Diffractometer	Bruker SMART CCD area-detector
Absorption correction	Multi-scan (SADABS; Sheldrick, 1996)
T_min, T_max	0.594, 0.863
No. of measured, independent and observed [I > 2σ(I)] reflections	8428, 3715, 2104
R_int	0.042
(sin θ/λ)_max (Å⁻¹)	0.595

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.060, 0.197, 1.10
No. of reflections	3715
No. of parameters	200
No. of restraints	483
H-atom treatment	H-atom parameters constrained
Δρ_max, Δρ_min (e Å⁻³)	0.96, −0.51

Computer programs: SMART (Siemens, 1996), SAINT (Siemens, 1996), SHELXS97 (Sheldrick, 1997a), SHELXL97 (Sheldrick, 1997a), SHELXTL (Sheldrick, 1997b).

Acknowledgements

We thank the National Natural Science Foundation of China (20771053) and the Natural Science Foundation of Shandong Province (2005ZX09) for financial support.

References

Addison, A. W., Rao, T. N., Reedijk, J., Rijn, J. V. & Verschoor, G. C. (1984). J. Chem. Soc. Dalton Trans. pp. 1349–1356. CSD CrossRef Web of Science Google Scholar
Ma, C., Li, J., Zhang, R. & Wang, D. (2006). J. Organomet. Chem., 691, 1713–1721. Web of Science CSD CrossRef CAS Google Scholar
Sheldrick, G. M. (1996). SADABS. University of Göttingen, Germany. Google Scholar
Sheldrick, G. M. (1997a). SHELXL97 and SHELXS97. University of Göttingen, Germany. Google Scholar
Sheldrick, G. M. (1997b). SHELXTL. Version 5.1. Bruker AXS Inc., Madison, Wisconsin, USA. Google Scholar
Siemens (1996). SMART and SAINT. Siemens Analytical X-ray Instruments Inc., Madison, Wisconsin, USA. Google Scholar