Secondary bonding in di­methyl­bis­(morpholine-4-carbodi­thio­ato-κ2S,S′)tin(IV): crystal structure and Hirshfeld surface analysis

Zaldi, N.B.; Hussen, R.S.D.; Lee, S.M.; Halcovitch, N.R.; Jotani, M.M.; Tiekink, E.R.T.

doi:10.1107/S2056989017006855

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Volume 73| Part 6| June 2017| Pages 842-848

https://doi.org/10.1107/S2056989017006855

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Secondary bonding in dimethylbis(morpholine-4-carbodithioato-κ²S,S′)tin(IV): crystal structure and Hirshfeld surface analysis

Nordiyana Binti Zaldi,^a Rusnah Syahila Duali Hussen,^a See Mun Lee,^b Nathan R. Halcovitch,^c Mukesh M. Jotani ^d ‡ and Edward R. T. Tiekink ^e ^*

^aDepartment of Chemistry, University of Malaya, 50603 Kuala Lumpur, Malaysia, ^bResearch Centre for Crystalline Materials, School of Science and Technology, Sunway University, 47500 Bandar Sunway, Selangor Darul Ehsan, Malaysia, ^cDepartment of Chemistry, Lancaster University, Lancaster LA1 4YB, United Kingdom, ^dDepartment of Physics, Bhavan's Sheth R. A. College of Science, Ahmedabad, Gujarat 380 001, India, and ^eResearch Centre for Chemical Crystallography, School of Science and Technology, Sunway University, 47500 Bandar Sunway, Selangor Darul Ehsan, Malaysia
^*Correspondence e-mail: edwardt@sunway.edu.my

Edited by W. T. A. Harrison, University of Aberdeen, Scotland (Received 4 May 2017; accepted 7 May 2017; online 12 May 2017)

The title compound, [Sn(CH₃)₂(C₅H₈NOS₂)₂], has the Sn^IV atom bound by two methyl groups which lie over the weaker Sn—S bonds formed by two asymmetrically chelating dithiocarbamate ligands so that the coordination geometry is skew-trapezoidal bipyramidal. The most prominent feature of the molecular packing are secondary Sn⋯S interactions [Sn⋯S = 3.5654 (7) Å] that lead to centrosymmetric dimers. These are connected into a three-dimensional architecture via methylene-C—H⋯S and methyl-C—H⋯O(morpholino) interactions. The Sn⋯S interactions are clearly evident in the Hirshfeld surface analysis of the title compound along with a number of other intermolecular contacts.

Keywords: crystal structure; organotin; dithiocarbamate; tetrel bonding; Hirshfeld surface analysis.

CCDC reference: 1548414

1. Chemical context

Both binary tin and organotin dithiocarbamates, R_nSn(S₂CNRR′)_m for n + m = 4, are well known to exhibit potential biological properties, e.g. anti-cancer (Ferreira et al., 2014 ), anti-fungal (Yu et al., 2014 ) and anti-microbial (Ferreira et al., 2012 ), as well to serve as useful molecular precursors for the generation of `SnS' nanomaterials (Kevin et al., 2015 ). The structural chemistry of this class of compound has also attracted considerable interest over the years owing to the occurrence of significant structural diversity observed in seemingly closely related compounds (Tiekink, 2008 ). As a case in point and related to the title compound, [Sn(CH₃)₂(C₅H₈NOS₂)₂] (I), reported herein, are the variations in molecular structure observed for the diorganotin bis(dithiocarbamate)s as discussed in the recent literature (Muthalib et al., 2014 ; Mohamad et al., 2016 , 2017 ). These R₂Sn(S₂CNRR')₂ structures are known to adopt four distinct coordination geometries with the majority being skew-trapezoidal bipyramidal or octahedral, each based on C₂S₄ donor sets. Fewer examples are known for five-coordinate, trigonal–bipyramidal species, e.g. (t-Bu)₂Sn(S₂CNMe₂)₂ in which one dithiocarbamate ligand is monodentate (Kim et al., 1987 ), and seven-coordinate, pentagonal–bipyramidal, e.g. [MeOC(=O)CH₂CH₂]₂Sn(S₂CNMe)₂ where the carbonyl-O atom of one Sn-bound organic substituent is also coordinating the tin atom (Ng et al., 1989 ). This last example is of interest as it demonstrates tin may in fact increase its coordination number by additional interactions. When additional interactions of this type occur intermolecularly, they are termed secondary bonding or tetrel bonding as a Group IV element, tin, is involved (Alcock, 1972 ; Marín-Luna et al., 2016 ; Tiekink, 2017 ). Generally, secondary interactions do not occur for R₂Sn(S₂CNRR')₂ structures as the strong chelating ability of the dithiocarbamate ligand reduces the Lewis acidity of the tin atom. However, in (I) such secondary Sn⋯S interactions do in fact occur. In a continuation of work in this area, herein the synthesis and crystal and molecular structures of (I) are described as well as an analysis of the Hirshfeld surface with a particular emphasis on investigating the role of the secondary Sn⋯S interaction.

2. Structural commentary

The Sn^IV atom in the title compound (I), Fig. 1, adopts one of the common coordination geometries found for R₂Sn(S₂CNRR')₂ molecules, i.e. skew-trapezoidal bipyramidal rather than octahedral (Tiekink, 2008). This arises as the chelating dithiocarbamate ligands have asymmetric Sn—S bond lengths, Table 1. The values of Δ(Sn—S) = [d(Sn—S_long) − d(Sn—S_short] for the S1- and S3-dithiocarbamate ligands are approximately the same at 0.35 Å, but the comparable bonds formed by the S3-dithiocarbamate ligand are systematically longer than those formed by the S1-dithiocarbamate ligand by approximately 0.02 Å, Table 1. The asymmetry in the Sn—S bond lengths is reflected in the disparity in the associated C—S bond lengths with the sulfur atom forming the longer Sn—S bond being involved in the significantly shorter, by approximately 0.05 Å, C—S bond, Table 1. Consistent with the skew-trapezoidal bipyramidal geometry about the Sn^IV atom, the Sn-bound methyl substituents are directed over the longer Sn—S bonds and define an angle of 148.24 (11)° at the tin atom. The angle subtended at the tin atom by the strongly bound sulfur atoms of 85.878 (19)° is significantly less than that formed by the weakly bound sulfur atoms, i.e. 143.066 (18)°, and is largely responsible for the formation of the skew-trapezoidal plane about the tin atom.

Table 1
Selected geometric parameters (Å, °)

Sn—S1	2.5429 (6)	Sn—C12	2.111 (3)
Sn—S2	2.8923 (6)	C1—S1	1.747 (3)
Sn—S3	2.5649 (7)	C1—S2	1.702 (3)
Sn—S4	2.9137 (6)	C6—S3	1.750 (3)
Sn—C11	2.132 (3)	C6—S4	1.697 (3)

S1—Sn—S2	65.935 (19)	S2—Sn—C12	84.93 (8)
S1—Sn—S3	85.878 (19)	S3—Sn—S4	65.137 (18)
S1—Sn—S4	150.95 (2)	S3—Sn—C12	102.37 (8)
S1—Sn—C11	99.49 (8)	S3—Sn—C11	99.28 (8)
S1—Sn—C12	104.96 (8)	S4—Sn—C11	84.20 (8)
S2—Sn—S3	151.798 (18)	S4—Sn—C12	84.15 (7)
S2—Sn—S4	143.066 (18)	C11—Sn—C12	148.24 (11)
S2—Sn—C11	86.87 (8)

Figure 1
The molecular structure of (I)

, showing the atom-labelling scheme and displacement ellipsoids at the 50% probability level.

3. Supramolecular features

An interesting feature of the molecular packing in (I) is the formation of a supramolecular dimer sustained by Sn⋯S secondary interactions, as shown in Fig. 2a, where two long edges of the translationally displaced trapezoidal planes approach each other to form the interactions. Here, Sn⋯S4ⁱ is 3.5654 (7) Å, which is approximately 0.4 Å shorter than the sum of the van der Waals radii of Sn and S of 3.97 Å (Bondi, 1964 ); symmetry operation (i): 1 − x, 1 − y, 1 − z. Connections between the dimeric aggregates are of the type methylene-C—H⋯S and methyl-C—H⋯O(morpholino), Table 2, and these interactions combine to generate a three-dimensional architecture, Fig. 2b.

Table 2
Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
C10—H10A⋯S1ⁱ	0.99	2.86	3.809 (3)	161
C12—H12C⋯O1ⁱⁱ	0.98	2.47	3.399 (4)	158
Symmetry codes: (i) $[x-{\script{3\over 2}}, -y-{\script{1\over 2}}, z-{\script{3\over 2}}]$ ; (ii) -x+2, -y+1, -z+1.

Figure 2
The molecular packing in (I)

, showing (a) a supramolecular dimer sustained by Sn⋯S secondary interactions shown as black dashed lines and (b) a view of the unit-cell contents in projection down the a axis. The C—H⋯S and C—H⋯O interactions are shown as orange and blue dashed lines, respectively.

4. Hirshfeld surface analysis

The Hirshfeld surfaces calculated on the structure of (I) also provide insight into the supramolecular association through secondary Sn⋯S, S⋯S and other contacts, and was performed as per recent publications on related organotin dithiocarbamate structures (Mohamad et al., 2017, 2016). The broad, bright-red spots appearing near the Sn and S4 atoms on the Hirshfeld surfaces mapped over d_norm in Fig. 3a indicate the formation of the supramolecular dimer through secondary Sn⋯S contacts. On the Hirshfeld surface mapped over electrostatic potential in Fig. 4, these interactions are represented by the blue and red regions around these atoms, respectively. The faint-red spot appearing between the above bright-red spots near the S4 atom indicates the short inter-atomic S⋯S contact, Table 3, between S4 atoms lying on diagonally opposite vertices of a parallelogram formed by symmetry-related Sn and S4 atoms, Fig. 5a. The pair of bright-red spots appearing near the methyl-H12C and morpholine-O1 atoms in Fig. 3b represent the respective donor and acceptor atoms of the C12—H⋯O1 interaction. The comparatively weaker methylene-C10—H⋯S1 interaction is viewed as a pair of faint-red spots near these atoms in Fig. 3b. It is important to note from the immediate environments about a reference molecule within d_norm-mapped Hirshfeld surfaces highlighting intermolecular interactions in Fig. 5 that the secondary Sn⋯S and S⋯S contacts are on one side of the Hirshfeld surface while the atoms participating in C—H⋯O and C—H⋯S interactions are on the other side of the surface.

Table 3
Summary of short inter-atomic contacts (Å) in (I)

Contact	distance	symmetry operation
S4⋯S4	3.5835 (10)	1 − x, 1 − y, −z
S2⋯H12B	2.99	$[{3\over 2}]$ − x, $[{1\over 2}]$ + y, $[{1\over 2}]$ − z
S3⋯H5B	2.94	1 − x, 1 − y, 1 − z
S4⋯H11C	2.94	1 − x, 1 − y, − z
O2⋯H2A	2.63	$[{1\over 2}]$ − x, − $[{1\over 2}]$ + y, $[{1\over 2}]$ − z
O2⋯H5B	2.70	$[{1\over 2}]$ − x, − $[{1\over 2}]$ + y, $[{1\over 2}]$ − z
C1⋯H3A	2.88	2 − x, 1 − y, 1 − z
C3⋯H12C	2.86	2 − x, 1 − y, 1 − z
H2A⋯H11C	2.36	$[{1\over 2}]$ + x, $[{3\over 2}]$ − y, $[{1\over 2}]$ + z

Figure 3
Two views of the Hirshfeld surface for (I)

plotted over d_norm in the range −0.050 to 1.780 au.

Figure 4
A view of Hirshfeld surface for (I)

mapped over the calculated electrostatic potential in the range −0.053 to +0.078 au. The red and blue regions represent negative and positive electrostatic potentials, respectively.

Figure 5
Views of Hirshfeld surfaces mapped over d_norm about a reference molecule showing (a) secondary Sn⋯S/S⋯Sn and S⋯S contacts by sky-blue and red dashed lines, respectively and (b) C—H⋯O and C—H⋯S interactions by black dashed lines

The overall two-dimensional fingerprint plot, Fig. 6a, and those delineated into H⋯H, S⋯H/H⋯S, O⋯H/H⋯O, C⋯H/H⋯C, N⋯H/H⋯N, Sn⋯S/S⋯Sn and S⋯S contacts (McKinnon et al., 2007 ) are illustrated in Fig. 6b–h, respectively; the relative contributions from the various contacts to the Hirshfeld surfaces are summarized in Table 4.

Table 4
Percentage contributions of inter-atomic contacts to the Hirshfeld surfaces for (I)

Contact	percentage contribution
H⋯H	56.8
S⋯H/H⋯S	27.2
O⋯H/H⋯O	9.9
C⋯/H⋯C	4.0
N⋯H/H⋯N	1.1
Sn⋯S/S⋯Sn	0.5
S⋯S	0.5

Figure 6
(a) The full two-dimensional fingerprint plot for (I)

and fingerprint plots delineated into (b) H⋯H, (c) S⋯H/H⋯S, (d) O⋯H/H⋯O, (e) C⋯H/H⋯C, (f) N⋯H/H⋯H, (g) Sn⋯S/S⋯Sn and (h) S⋯S contacts.

In the fingerprint plot delineated into H⋯H contacts, Fig. 6b, the points forming the single short peak at d_e + d_i < 2.4 Å are indicative of the short inter-atomic H⋯H contact listed in Table 3. The involvement of S1 in the C—H⋯S interaction and other sulfur atoms in short inter-atomic S⋯H/H⋯S contacts, Table 3, results in an overall 27.2% contribution to the Hirshfeld surface. In the fingerprint plot delineated into S⋯H/H⋯S contacts, Fig. 6c, they appear as overlapping donor–acceptor regions showing corners and a pair of greenish regions of greater intensity having short spikes at d_e + d_i ∼ 2.9 Å. The C—H⋯O contact is evident from the two-dimensional fingerprint plot delineated into O⋯H/H⋯O contacts, Fig. 6d, as the pair of tips at d_e + d_i ∼ 2.5 Å in the forceps-like distribution. The short inter-atomic O⋯H/H⋯O contacts, Table 3, in the plot appear as faint-green points in a slightly scattered form emanating from d_e + d_i ∼ 2.9 Å. The pair of short spikes at d_e + d_i < 2.9 Å overlapping on the well separated donor and acceptor regions in the fingerprint plot delineated into C⋯H/H⋯C contacts, Fig. 6e, indicate the influence of short inter-atomic C⋯H/H⋯C contacts, Table 3. The presence of secondary Sn⋯S and short S⋯S contacts in the structure is also confirmed from the respective plots through the distribution of points as a pair of thin line segments, Fig. 6f, and a triangle, Fig. 6g, respectively, having minimum d_e + d_i distances at around 3.5 Å and 3.6 Å, respectively. The 1.1% contribution from N⋯H/H⋯N contacts, Fig. 6h, to the Hirshfeld surface reflects an insignificant influence upon the molecular packing as the inter-atomic separations are greater than the sum of the respective van der Waals radii.

5. Database survey

The Cambridge Crystallographic Database (Groom et al., 2016 ) contains over 110 molecules of the general formula R₂Sn(S₂CNRR')₂. Of these, 12 feature secondary Sn⋯S interactions which, with (I), means approximately 10% of all R₂Sn(S₂CNRR')₂ structures have Sn⋯S secondary interactions. Selected geometric details for the 13 structures are collated in Table 5. The Sn⋯S interactions assemble molecules in their crystals into three distinct structural motifs. The common motif, A, is a dimeric aggregate disposed about a centre of inversion, as is in (I), and is found in the majority of crystals, i.e. nine. This motif is illustrated in Fig. 7a for (PhCH₂)₂Sn(S₂CNEt₂)₂ (Yin et al., 2003 ). A second zero-dimensional motif, B, is also known and is readily related to A. In the structure of Me₂Sn(S₂CN(Et)CH₂C₆H₄N-4)₂ (Barba et al., 2012 ), two independent molecules comprise the asymmetric unit. One of these self-assembles about a centre of inversion as for motif A. The nitrogen atom of each pendent 4-pyridyl group of the dimeric aggregate thus assembled interacts with the tin atom of the second independent molecule via a Sn⋯N interaction to form the four-molecule aggregate shown in Fig. 7b. The final three molecules are binuclear owing to the presence of bis(dithiocarbamate) ligands and self-assemble into supramolecular chains. In {Me₂SnS₂CN(CH₂Ph)CH₂(1,3-C₆H₃)CH₂(PhCH₂)NCS₂SnMe₂}₂ (Santacruz-Juárez et al., 2008 ), the molecule is situated about a centre of inversion and each tin atom forms an Sn⋯S contact to generate a linear, supramolecular chain, motif C, Fig. 7c. A variation is seen in the crystal of Me₂SnS₂CN(CH₂CH₂-i-Pr)CH₂(1,3-C₆H₃)CH₂(PhCH₂)NCS₂SnMe₂}₂, where there are two independent, centrosymmetric molecules in the asymmetric unit. Here, the resulting supramolecular chain is twisted (Santacruz-Juárez et al., 2008) and is assigned as motif C′.

Table 5
Summary of Sn—S, Sn⋯S distances (Å) in R₂Sn(S₂CNRR′)₂ structures featuring secondary Sn⋯S interactions

R	R, R′	Sn—S_short, Sn—S_long	Sn⋯S	motif	Reference
Me	Et, Et	2.5174 (18), 2.961 (3); 2.528 (2), 2.9162 (17)	3.853 (2)	A	Morris & Schlemper (1979 )
Me	(CH₂CH₂)Me	2.5367 (14), 2.9171 (16); 2.5577 (15), 2.8953 (16)	3.6978 (18)	A	Zia-ur-Rehman et al. (2007 )
Me	(CH₂CH₂)O	2.5429 (6), 2.8923 (6); 2.5649 (7), 2.9137 (6)	3.5654 (7)	A	this work
C(H)=CH₂	Cy	2.514 (5), 2.914 (4); 2.536 (4), 2.914 (4)	3.662 (5)	A	Hall & Tiekink (1998 )
CH₂Ph	Et, Et	2.5310 (11), 2.8940 (11); 2.5396 (10), 2.9109 (11)	3.8161 (12)	A	Yin et al. (2003)
CH₂PhCl-2	(CH₂CH₂)NMe	2.5401 (13), 2.8050 (13); 2.5675 (13), 2.8675 (12)	3.9071 (13)	A	Yin & Xue (2005a )
CH₂PhCl-3^a	(CH₂CH₂)NEt	2.520 (3), 2.840 (3); 2.556 (2), 2.893 (3)	3.638 (3)	A	Xue et al. (2005 )
CH₂PhCl-4	(CH₂CH₂)NMe	2.534 (2), 2.968 (3); 2.550 (2), 2.858 (3)	3.765 (3)	A	Yin & Xue (2005b )
CH₂PhCN-4	Et, Et	2.524 (3), 2.885 (3); 2.537 (2), 2.879 (2)	3.821 (3)	A	Yin & Xue (2006 )
Me^b	Et; CH₂Ph	2.543 (2), 2.943 (2); 2.549 (2), 2.909 (2)	3.724 (3)	B	Barba et al. (2012)
		2.579 (2), 2.842 (2); 2.609 (2), 3.003 (2)	2.978 (5)^c
Me^d	CH₂Ph, 0.5(1,3-CH₂C₆H₄CH₂)	2.5086 (13), 2.8791 (15); 2.5217 (14), 3.1510 (16)	3.9641 (15)	C	Santacruz-Juárez et al. (2008)
Me^d,e	bicyclo[2.2.1]hept-2yl, 0.5(CH₂)₄	2.5179 (12), 2.9015 (13); 2.5321 (12), 2.9600 (13)	3.9453 (14)	C	Rojas-León et al. (2012 )
Me^f	(CH₂)₂ⁱPr, 0.5(1,3-CH₂C₆H₄CH₂)	2.5319 (18), 2.8855 (18); 2.5356 (17), 2.9663 (19)	4.0480 (19)	C′	Santacruz-Juárez et al. (2008)
		2.5306 (17), 2.9492 (19); 2.5402 (19), 2.9633 (19)	3.7050 (17)
Notes: (a) piperazine mono-solvate; (b) two molecules in the asymmetric unit; (c) Sn⋯N secondary interaction; (d) the binuclear molecule is located about a centre of inversion; (e) CDCl₃ di-solvate per binuclear entity; (f) two molecules in the asymmetric unit with each being located about a centre of inversion.

Figure 7
Supramolecular aggregation sustained by secondary Sn⋯S interactions (black dashed lines) leading to (a) dimeric aggregates in (PhCH₂)₂Sn(S₂CNEt₂)₂, (b) four-molecule aggregates in Me₂Sn(S₂CN(Et)CH₂C₆H₄N-4)₂ and (c) linear supramolecular chain in {Me₂SnS₂CN(CH₂Ph)CH₂(1,3-C₆H₃)CH₂(PhCH₂)NCS₂SnMe₂}₂.

The common feature of all motifs listed in Table 5 is that it is one of the weakly bound sulfur atoms that forms the secondary Sn⋯S interaction. Further, the tin-bound groups are relatively sterically unencumbered, allowing for the close approach of sulfur donors to the tin atoms. There are no geometric correlations. However, reflecting the weak nature of these interactions, the sulfur atom forming the Sn⋯S contact does not necessarily form the weaker of the Sn—S_long interactions in each molecule. The range of Sn⋯S distances spans nearly 0.5 Å but, again, no correlations between these distances and the S_long—Sn—S_long angles is apparent, i.e. it might be expected that the shorter Sn⋯S interactions would result in wider S_long—Sn—S_long angles.

6. Synthesis and crystallization

All chemicals and solvents were used as purchased without purification, and all reactions were carried out under ambient conditions. The melting point was determined using an Electrothermal digital melting point apparatus and was uncorrected. The IR spectrum for (I) was obtained on a Perkin Elmer Spectrum 400 FT Mid-IR/Far-IR spectrophotometer in the range 4000 to 400 cm⁻¹. The ¹H NMR spectrum was recorded at room temperature in CDCl₃ solution on a Jeol ECA 400 MHz FT–NMR spectrometer.

Sodium morpholinedithiocarbamate (prepared from the reaction between carbon disulfide and morpholine (Merck) in the presence of sodium hydroxide; 1.0 mmol, 0.185 g) in methanol (20 ml) was added to dimethyltin dichloride (Merck, 1.0 mmol, 0.219 g) in methanol (10 ml). The resulting mixture was stirred and refluxed for 2 h. The filtrate was evaporated until an off-white precipitate was obtained. The precipitate was recrystallized from methanol solution by slow evaporation to yield colourless prisms. Yield: 0.305 g, 64.4%; m.p.: 448 K. IR (cm⁻¹): 1465(s), 1423(s) ν(C—N), 1222(s) ν(C—O), 1110(m), 994(s) ν(C—S), 541(m) ν(Sn—C) cm⁻¹. ¹H NMR (CDCl₃): 4.18 (s, 8H, CH₂O), 3.77 (s, 8H, NCH₂), 1.54 (s, 6H, -CH₃).

7. Refinement

Crystal data, data collection and structure refinement details are summarized in Table 6. Carbon-bound H atoms were placed in calculated positions (C—H = 0.98–0.99 Å) and were included in the refinement in the riding-model approximation, with U_iso(H) set to 1.2–1.5U_eq(C). Owing to poor agreement, one reflection, i.e. ( $[\overline{12}]$ 1 5), was omitted from the final cycles of refinement.

Table 6
Experimental details

Crystal data
Chemical formula	[Sn(CH₃)₂(C₅H₈NOS₂)₂]
M_r	473.24
Crystal system, space group	Monoclinic, P2₁/n
Temperature (K)	100
a, b, c (Å)	10.1472 (1), 13.6653 (1), 13.8122 (1)
β (°)	104.959 (1)
V (Å³)	1850.36 (3)
Z	4
Radiation type	Cu Kα
μ (mm⁻¹)	15.25
Crystal size (mm)	0.24 × 0.09 × 0.06

Data collection
Diffractometer	Agilent SuperNova, Dual, Cu at zero, AtlasS2
Absorption correction	Gaussian (CrysAlis PRO; Rigaku Oxford Diffraction, 2015 $[Rigaku Oxford Diffraction (2015). CrysAlis PRO. Agilent Technologies Inc., Santa Clara, CA, USA.]$ )
T_min, T_max	0.242, 0.759
No. of measured, independent and observed [I > 2σ(I)] reflections	19588, 3865, 3809
R_int	0.031
(sin θ/λ)_max (Å⁻¹)	0.631

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.024, 0.065, 1.07
No. of reflections	3865
No. of parameters	192
H-atom treatment	H-atom parameters constrained
Δρ_max, Δρ_min (e Å⁻³)	0.45, −0.50
Computer programs: CrysAlis PRO (Rigaku Oxford Diffraction, 2015 $[Rigaku Oxford Diffraction (2015). CrysAlis PRO. Agilent Technologies Inc., Santa Clara, CA, USA.]$ ), SHELXS (Sheldrick, 2008 ), SHELXL2014 (Sheldrick, 2015 ), ORTEP-3 for Windows (Farrugia, 2012 ), DIAMOND (Brandenburg, 2006 ) and publCIF (Westrip, 2010 ).

Supporting information

CCDC reference: 1548414

Crystal structure: contains datablocks I, global. DOI: https://doi.org/10.1107/S2056989017006855/hb7675sup1.cif

Structure factors: contains datablock I. DOI: https://doi.org/10.1107/S2056989017006855/hb7675Isup2.hkl

checkCIF report

Computing details top

Data collection: CrysAlis PRO (Rigaku Oxford Diffraction, 2015); cell refinement: CrysAlis PRO (Rigaku Oxford Diffraction, 2015); data reduction: CrysAlis PRO (Rigaku Oxford Diffraction, 2015); program(s) used to solve structure: SHELXS (Sheldrick, 2008); program(s) used to refine structure: SHELXL2014 (Sheldrick, 2015); molecular graphics: ORTEP-3 for Windows (Farrugia, 2012) and DIAMOND (Brandenburg, 2006); software used to prepare material for publication: publCIF (Westrip, 2010).

Dimethylbis(morpholine-4-carbodithioato-κ²S,S')tin(IV) top

Crystal data top

[Sn(CH₃)₂(C₅H₈NOS₂)₂]	F(000) = 952
M_r = 473.24	D_x = 1.699 Mg m⁻³
Monoclinic, P2₁/n	Cu Kα radiation, λ = 1.54184 Å
a = 10.1472 (1) Å	Cell parameters from 14936 reflections
b = 13.6653 (1) Å	θ = 3.2–76.6°
c = 13.8122 (1) Å	µ = 15.25 mm⁻¹
β = 104.959 (1)°	T = 100 K
V = 1850.36 (3) Å³	Prism, colourless
Z = 4	0.24 × 0.09 × 0.06 mm

Data collection top

Agilent SuperNova, Dual, Cu at zero, AtlasS2 diffractometer	3865 independent reflections
Radiation source: micro-focus sealed X-ray tube, SuperNova (Cu) X-ray Source	3809 reflections with I > 2σ(I)
Mirror monochromator	R_int = 0.031
ω scans	θ_max = 76.8°, θ_min = 4.6°
Absorption correction: gaussian (CrysAlis PRO; Rigaku Oxford Diffraction, 2015)	h = −12→12
T_min = 0.242, T_max = 0.759	k = −13→17
19588 measured reflections	l = −17→17

Refinement top

Refinement on F²	0 restraints
Least-squares matrix: full	Hydrogen site location: inferred from neighbouring sites
R[F² > 2σ(F²)] = 0.024	H-atom parameters constrained
wR(F²) = 0.065	w = 1/[σ²(F_o²) + (0.0322P)² + 2.5554P] where P = (F_o² + 2F_c²)/3
S = 1.07	(Δ/σ)_max = 0.001
3865 reflections	Δρ_max = 0.45 e Å⁻³
192 parameters	Δρ_min = −0.50 e Å⁻³

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.

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

	x	y	z	U_iso*/U_eq
Sn	0.54609 (2)	0.47196 (2)	0.20083 (2)	0.01811 (6)
S1	0.60114 (7)	0.47340 (5)	0.39117 (5)	0.02266 (14)
S2	0.76105 (7)	0.60660 (4)	0.29478 (4)	0.02164 (13)
S3	0.36959 (7)	0.34005 (5)	0.20926 (4)	0.02368 (13)
S4	0.38512 (7)	0.40224 (5)	0.00694 (4)	0.02491 (14)
O1	0.9722 (2)	0.62761 (17)	0.68544 (15)	0.0315 (4)
O2	−0.1073 (2)	0.28893 (17)	−0.02186 (16)	0.0334 (5)
N1	0.7980 (2)	0.59004 (16)	0.49256 (16)	0.0216 (4)
N2	0.1802 (2)	0.29886 (17)	0.04134 (16)	0.0235 (5)
C1	0.7294 (3)	0.56096 (18)	0.40120 (18)	0.0188 (5)
C2	0.8983 (3)	0.6702 (2)	0.5084 (2)	0.0245 (5)
H2A	0.8543	0.7321	0.5205	0.029*
H2B	0.9318	0.6786	0.4477	0.029*
C3	1.0169 (3)	0.6474 (2)	0.5975 (2)	0.0294 (6)
H3A	1.0670	0.5899	0.5817	0.035*
H3B	1.0805	0.7036	0.6103	0.035*
C4	0.8853 (3)	0.5444 (2)	0.6688 (2)	0.0285 (6)
H4A	0.8579	0.5290	0.7309	0.034*
H4B	0.9355	0.4874	0.6522	0.034*
C5	0.7594 (3)	0.5622 (2)	0.58459 (19)	0.0253 (5)
H5A	0.7031	0.5021	0.5722	0.030*
H5B	0.7044	0.6151	0.6037	0.030*
C6	0.2990 (3)	0.34278 (18)	0.07953 (18)	0.0202 (5)
C7	0.1020 (3)	0.2459 (2)	0.1005 (2)	0.0267 (6)
H7A	0.1494	0.2502	0.1726	0.032*
H7B	0.0943	0.1760	0.0810	0.032*
C8	−0.0379 (3)	0.2905 (2)	0.0819 (2)	0.0310 (6)
H8A	−0.0919	0.2539	0.1201	0.037*
H8B	−0.0296	0.3590	0.1061	0.037*
C9	−0.0330 (3)	0.3430 (2)	−0.0777 (2)	0.0303 (6)
H9A	−0.0261	0.4120	−0.0551	0.036*
H9B	−0.0829	0.3418	−0.1495	0.036*
C10	0.1087 (3)	0.3021 (2)	−0.06570 (19)	0.0249 (5)
H10A	0.1028	0.2354	−0.0945	0.030*
H10B	0.1599	0.3439	−0.1020	0.030*
C11	0.4147 (3)	0.5961 (2)	0.1692 (2)	0.0260 (5)
H11A	0.4573	0.6513	0.2110	0.039*
H11B	0.3275	0.5803	0.1837	0.039*
H11C	0.3987	0.6137	0.0983	0.039*
C12	0.7041 (3)	0.38945 (19)	0.1667 (2)	0.0242 (5)
H12A	0.7154	0.4095	0.1012	0.036*
H12B	0.6809	0.3197	0.1650	0.036*
H12C	0.7894	0.4008	0.2181	0.036*

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
Sn	0.02190 (10)	0.01935 (10)	0.01260 (9)	0.00090 (6)	0.00357 (6)	−0.00052 (5)
S1	0.0275 (3)	0.0258 (3)	0.0140 (3)	−0.0074 (2)	0.0041 (2)	−0.0009 (2)
S2	0.0290 (3)	0.0213 (3)	0.0154 (3)	−0.0032 (2)	0.0069 (2)	−0.0006 (2)
S3	0.0290 (3)	0.0286 (3)	0.0117 (3)	−0.0060 (2)	0.0022 (2)	0.0025 (2)
S4	0.0282 (3)	0.0332 (3)	0.0131 (3)	−0.0068 (3)	0.0051 (2)	0.0014 (2)
O1	0.0294 (10)	0.0400 (11)	0.0208 (9)	−0.0022 (9)	−0.0013 (8)	−0.0006 (8)
O2	0.0246 (10)	0.0416 (12)	0.0313 (11)	−0.0046 (9)	0.0025 (8)	−0.0013 (9)
N1	0.0257 (11)	0.0236 (10)	0.0149 (10)	−0.0024 (9)	0.0041 (8)	−0.0016 (8)
N2	0.0258 (11)	0.0271 (11)	0.0163 (10)	−0.0043 (9)	0.0033 (9)	0.0012 (9)
C1	0.0234 (12)	0.0153 (11)	0.0168 (11)	0.0006 (9)	0.0036 (9)	−0.0018 (9)
C2	0.0249 (13)	0.0256 (13)	0.0201 (12)	−0.0042 (10)	0.0007 (10)	−0.0027 (10)
C3	0.0248 (13)	0.0337 (15)	0.0273 (14)	0.0014 (11)	0.0023 (11)	0.0002 (12)
C4	0.0323 (15)	0.0301 (14)	0.0208 (13)	0.0020 (12)	0.0029 (11)	0.0029 (11)
C5	0.0291 (14)	0.0320 (14)	0.0140 (11)	−0.0044 (11)	0.0040 (10)	−0.0019 (10)
C6	0.0233 (12)	0.0204 (11)	0.0160 (11)	0.0013 (9)	0.0037 (9)	−0.0002 (9)
C7	0.0293 (14)	0.0290 (13)	0.0212 (12)	−0.0091 (11)	0.0053 (11)	0.0022 (11)
C8	0.0284 (14)	0.0373 (15)	0.0278 (14)	−0.0074 (12)	0.0083 (11)	−0.0038 (12)
C9	0.0300 (14)	0.0314 (15)	0.0253 (13)	−0.0019 (12)	−0.0002 (11)	−0.0020 (11)
C10	0.0265 (13)	0.0295 (13)	0.0161 (12)	−0.0074 (11)	0.0010 (10)	−0.0027 (10)
C11	0.0279 (13)	0.0244 (13)	0.0260 (13)	0.0111 (11)	0.0074 (11)	0.0042 (10)
C12	0.0264 (13)	0.0222 (12)	0.0228 (12)	0.0052 (10)	0.0043 (10)	−0.0042 (10)

Geometric parameters (Å, º) top

Sn—S1	2.5429 (6)	C3—H3A	0.9900
Sn—S2	2.8923 (6)	C3—H3B	0.9900
Sn—S3	2.5649 (7)	C4—C5	1.509 (4)
Sn—S4	2.9137 (6)	C4—H4A	0.9900
Sn—C11	2.132 (3)	C4—H4B	0.9900
Sn—C12	2.111 (3)	C5—H5A	0.9900
C1—S1	1.747 (3)	C5—H5B	0.9900
C1—S2	1.702 (3)	C7—C8	1.505 (4)
C6—S3	1.750 (3)	C7—H7A	0.9900
C6—S4	1.697 (3)	C7—H7B	0.9900
O1—C4	1.421 (4)	C8—H8A	0.9900
O1—C3	1.428 (4)	C8—H8B	0.9900
O2—C9	1.418 (4)	C9—C10	1.512 (4)
O2—C8	1.424 (4)	C9—H9A	0.9900
N1—C1	1.335 (3)	C9—H9B	0.9900
N1—C2	1.472 (3)	C10—H10A	0.9900
N1—C5	1.473 (3)	C10—H10B	0.9900
N2—C6	1.328 (4)	C11—H11A	0.9800
N2—C7	1.468 (3)	C11—H11B	0.9800
N2—C10	1.470 (3)	C11—H11C	0.9800
C2—C3	1.515 (4)	C12—H12A	0.9800
C2—H2A	0.9900	C12—H12B	0.9800
C2—H2B	0.9900	C12—H12C	0.9800

S1—Sn—S2	65.935 (19)	H4A—C4—H4B	108.0
S1—Sn—S3	85.878 (19)	N1—C5—C4	110.3 (2)
S1—Sn—S4	150.95 (2)	N1—C5—H5A	109.6
S1—Sn—C11	99.49 (8)	C4—C5—H5A	109.6
S1—Sn—C12	104.96 (8)	N1—C5—H5B	109.6
S2—Sn—S3	151.798 (18)	C4—C5—H5B	109.6
S2—Sn—S4	143.066 (18)	H5A—C5—H5B	108.1
S2—Sn—C11	86.87 (8)	N2—C6—S4	122.32 (19)
S2—Sn—C12	84.93 (8)	N2—C6—S3	119.1 (2)
S3—Sn—S4	65.137 (18)	S4—C6—S3	118.56 (15)
S3—Sn—C12	102.37 (8)	N2—C7—C8	109.1 (2)
S3—Sn—C11	99.28 (8)	N2—C7—H7A	109.9
S4—Sn—C11	84.20 (8)	C8—C7—H7A	109.9
S4—Sn—C12	84.15 (7)	N2—C7—H7B	109.9
C11—Sn—C12	148.24 (11)	C8—C7—H7B	109.9
C1—S1—Sn	92.73 (8)	H7A—C7—H7B	108.3
C1—S2—Sn	82.29 (9)	O2—C8—C7	111.4 (2)
C6—S3—Sn	92.55 (9)	O2—C8—H8A	109.3
C6—S4—Sn	82.27 (9)	C7—C8—H8A	109.3
C4—O1—C3	109.5 (2)	O2—C8—H8B	109.3
C9—O2—C8	110.2 (2)	C7—C8—H8B	109.3
C1—N1—C2	122.2 (2)	H8A—C8—H8B	108.0
C1—N1—C5	123.3 (2)	O2—C9—C10	111.8 (2)
C2—N1—C5	113.0 (2)	O2—C9—H9A	109.2
C6—N2—C7	124.6 (2)	C10—C9—H9A	109.2
C6—N2—C10	123.2 (2)	O2—C9—H9B	109.2
C7—N2—C10	112.2 (2)	C10—C9—H9B	109.2
N1—C1—S2	122.6 (2)	H9A—C9—H9B	107.9
N1—C1—S1	118.35 (19)	N2—C10—C9	109.3 (2)
S2—C1—S1	119.04 (14)	N2—C10—H10A	109.8
N1—C2—C3	110.0 (2)	C9—C10—H10A	109.8
N1—C2—H2A	109.7	N2—C10—H10B	109.8
C3—C2—H2A	109.7	C9—C10—H10B	109.8
N1—C2—H2B	109.7	H10A—C10—H10B	108.3
C3—C2—H2B	109.7	Sn—C11—H11A	109.5
H2A—C2—H2B	108.2	Sn—C11—H11B	109.5
O1—C3—C2	111.7 (2)	H11A—C11—H11B	109.5
O1—C3—H3A	109.3	Sn—C11—H11C	109.5
C2—C3—H3A	109.3	H11A—C11—H11C	109.5
O1—C3—H3B	109.3	H11B—C11—H11C	109.5
C2—C3—H3B	109.3	Sn—C12—H12A	109.5
H3A—C3—H3B	107.9	Sn—C12—H12B	109.5
O1—C4—C5	111.3 (2)	H12A—C12—H12B	109.5
O1—C4—H4A	109.4	Sn—C12—H12C	109.5
C5—C4—H4A	109.4	H12A—C12—H12C	109.5
O1—C4—H4B	109.4	H12B—C12—H12C	109.5
C5—C4—H4B	109.4

C2—N1—C1—S2	5.5 (4)	C7—N2—C6—S4	179.6 (2)
C5—N1—C1—S2	171.0 (2)	C10—N2—C6—S4	−3.5 (4)
C2—N1—C1—S1	−173.9 (2)	C7—N2—C6—S3	−0.7 (4)
C5—N1—C1—S1	−8.4 (3)	C10—N2—C6—S3	176.2 (2)
Sn—S2—C1—N1	179.7 (2)	Sn—S4—C6—N2	168.6 (2)
Sn—S2—C1—S1	−0.98 (13)	Sn—S4—C6—S3	−11.13 (13)
Sn—S1—C1—N1	−179.5 (2)	Sn—S3—C6—N2	−167.2 (2)
Sn—S1—C1—S2	1.11 (15)	Sn—S3—C6—S4	12.56 (15)
C1—N1—C2—C3	−143.1 (3)	C6—N2—C7—C8	122.6 (3)
C5—N1—C2—C3	50.1 (3)	C10—N2—C7—C8	−54.6 (3)
C4—O1—C3—C2	61.3 (3)	C9—O2—C8—C7	−60.3 (3)
N1—C2—C3—O1	−55.1 (3)	N2—C7—C8—O2	57.4 (3)
C3—O1—C4—C5	−61.7 (3)	C8—O2—C9—C10	59.5 (3)
C1—N1—C5—C4	142.5 (3)	C6—N2—C10—C9	−123.5 (3)
C2—N1—C5—C4	−50.8 (3)	C7—N2—C10—C9	53.7 (3)
O1—C4—C5—N1	56.3 (3)	O2—C9—C10—N2	−55.8 (3)

Hydrogen-bond geometry (Å, º) top

Cg1 is the centroid of the (C8–C13) ring.

D—H···A	D—H	H···A	D···A	D—H···A
C10—H10A···S1ⁱ	0.99	2.86	3.809 (3)	161
C12—H12C···O1ⁱⁱ	0.98	2.47	3.399 (4)	158

Symmetry codes: (i) x−3/2, −y−1/2, z−3/2; (ii) −x+2, −y+1, −z+1.

Summary of short inter-atomic contacts (Å) in (I) top

Contact	distance	symmetry operation
S4···S4	3.5835 (10)	1 - x, 1 - y, -z
S2···H12B	2.99	3/2 - x, 1/2 + y, 1/2 - z
S3···H5B	2.94	1 - x, 1 - y, 1 - z
S4···H11C	2.94	1 - x, 1 - y, - z
O2···H2A	2.63	1/2 - x, -1/2 + y, 1/2 - z
O2···H5B	2.70	1/2 - x, -1/2 + y, 1/2 - z
C1···H3A	2.88	2 - x, 1 - y, 1 - z
C3···H12C	2.86	2 - x, 1 - y, 1- z
H2A···H11C	2.36	1/2 + x, 3/2 - y, 1/2 + z

Percentage contributions of inter-atomic contacts to the Hirshfeld surfaces for (I) top

Contact	percentage contribution
H···H	56.8
S···H/H···S	27.2
O···H/H···O	9.9
C···/H···C	4.0
N···H/H···N	1.1
Sn···S/S···Sn	0.5
S···S	0.5

Summary of Sn—S, Sn···S distances (Å) in R₂Sn(S₂CNRR')₂ structures featuring secondary Sn···S interactions top

R	R, R^'	Sn—S_short, Sn—S_long	Sn···S	motif	Ref.
Me	Et, Et	2.5174 (18), 2.961 (3); 2.528 (2), 2.9162 (17)	3.853 (2)	A	Morris & Schlemper (1979)
Me	(CH₂CH₂)Me	2.5367 (14), 2.9171 (16); 2.5577 (15), 2.8953 (16)	3.6978 (18)	A	Zia-ur-Rehman et al. (2007)
Me	(CH₂CH₂)O	2.5429 (6), 2.8923 (6); 2.5649 (7), 2.9137 (6)	3.5654 (7)	A	this work
C(H)═CH₂	Cy	2.514 (5), 2.914 (4); 2.536 (4), 2.914 (4)	3.662 (5)	A	Hall & Tiekink (1998)
CH₂Ph	Et, Et	2.5310 (11), 2.8940 (11); 2.5396 (10), 2.9109 (11)	3.8161 (12)	A	Yin et al. (2003)
CH₂PhCl-2	(CH₂CH₂)NMe	2.5401 (13), 2.8050 (13); 2.5675 (13), 2.8675 (12)	3.9071 (13)	A	Yin & Xue (2005a)
CH₂PhCl-3^a	(CH₂CH₂)NEt	2.520 (3), 2.840 (3); 2.556 (2), 2.893 (3)	3.638 (3)	A	Xue et al. (2005)
CH₂PhCl-4	(CH₂CH₂)NMe	2.534 (2), 2.968 (3); 2.550 (2), 2.858 (3)	3.765 (3)	A	Yin & Xue (2005b)
CH₂PhCN-4	Et, Et	2.524 (3), 2.885 (3); 2.537 (2), 2.879 (2)	3.821 (3)	A	Yin & Xue (2006)
Me^b	Et; CH₂Ph	2.543 (2), 2.943 (2); 2.549 (2), 2.909 (2)	3.724 (3)	B	Barba et al. (2012)
		2.579 (2), 2.842 (2); 2.609 (2), 3.003 (2)	2.978 (5)^c
Me^d	CH₂Ph, 0.5(1,3-CH₂C₆H₄CH₂)	2.5086 (13), 2.8791 (15); 2.5217 (14), 3.1510 (16)	3.9641 (15)	C	Santacruz-Juárez et al. (2008)
Me^d^,^e	bicyclo[2.2.1]hept-2yl, 0.5(CH₂)₄	2.5179 (12), 2.9015 (13); 2.5321 (12), 2.9600 (13)	3.9453 (14)	C	Rojas-León et al. (2012)
Me^f	(CH₂)₂i-Pr, 0.5(1,3-CH₂C₆H₄CH₂)	2.5319 (18), 2.8855 (18); 2.5356 (17), 2.9663 (19)	4.0480 (19)	C'	Santacruz-Juárez et al. (2008)
		2.5306 (17), 2.9492 (19); 2.5402 (19), 2.9633 (19)	3.7050 (17)

Notes: (a) piperazine mono-solvate; (b) two molecules in the asymmetric unit; (c) Sn···N secondary interaction; (d) the binuclear molecule is located about a centre of inversion; (e) CDCl₃ di-solvate per binuclear entity; (f) two molecules in the asymmetric unit with each being located about a centre of inversion.

Footnotes

‡Additional correspondence author, e-mail: mmjotani@rediffmail.com.

Acknowledgements

The authors are grateful to Sunway University (INT-RRO-2017-096), the University of Malaya (award Nos. RP017B-14AFR and PG168-2016A) and the Ministry of Higher Education of Malaysia (MOHE) Fundamental Research Grant Scheme (grant No. FP033-2014B) for supporting this research.

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