metal-organic compounds\(\def\hfill{\hskip 5em}\def\hfil{\hskip 3em}\def\eqno#1{\hfil {#1}}\)

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ISSN: 2414-3146

Di­bromido­(N-phenyl­benzamidine-κN′)tin(II)

aInstitute of Applied Chemistry, Shanxi University, Taiyuan 030006, People's Republic of China
*Correspondence e-mail: 1103148896@qq.com

Edited by O. Blacque, University of Zürich, Switzerland (Received 14 February 2017; accepted 27 February 2017; online 28 February 2017)

The asymmetric unit of the title compound, [SnBr2(C13H12N2)], contains an amidine ligand and tin(II) bromide moiety. In the amidine ligand, the phenyl rings present a head-to-tail configuration mode. The tin atom is coordinated by the terminal N atom of the amidine ligand, and the two Br atoms extend to both sides of the Sn atom in a V-shape. The phenyl rings are twisted from the mean N/C/N plane by 26.14 (18) and 79.50 (8)°. The crystal structure features N—H⋯Br hydrogen bonds.

3D view (loading...)
[Scheme 3D1]
Chemical scheme
[Scheme 1]

Structure description

The representative amidinate ligand [RC(NR)2] is four-electron monoanionic and has a typical conjugated N—C—N construction, through which the negative charge is able to be delocalized so as to form chelating surroundings (Bai et al., 2010[Bai, S.-D., Tong, H.-B., Guo, J.-P., Zhou, M.-S., Liu, D.-S. & Yuan, S.-F. (2010). Polyhedron, 29, 262-269.]). Based on this backbone, amidinates have been widely ligated to transition metals (Edelmann, 1994[Edelmann, F. T. (1994). Coord. Chem. Rev. 137, 403-481.]), particularly the group 14 metallyl­enes tin(II). Tin(II) amidinates belong to the family of complexes bearing so-called spectator ligands which are commonly used for fine-tuning of the electronic as well as coordination properties of the metal atom (Chlupatý et al., 2015[Chlupatý, T., Růžičková, Z., Horáček, M., Alonso, M., De Proft, F., Kampová, H., Brus, J. & Růžička, A. (2015). Organometallics, 34, 606-615.]). Inter­esting features in the title compound arise from the highly catalytic activity in the ring-opening polymerization of caprolactone and aryl iso­cyanates to perhydro-1,3,5-triazine-2,4,6-triones (isocyanurates) in a living fashion, under mild conditions. As part of our studies in this area, the title compound (Fig. 1[link]) was prepared in a novel manner (reaction in Schlenk bottle by PhNH2, nBuLi, SiMe2Cl2, PhCN, SnCl2 and Br2) and we have determined its crystal structure. The compound is closely similar to the benzamidine with an o-tolyl substituent on the N atom, namely N2-o-tolyl­benzamidine (Zhang et al., 2008[Zhang, L.-Z. & Tong, H.-B. (2008). Acta Cryst. E64, o1276.]), which has no stannous bromine moiety attached.

[Figure 1]
Figure 1
The mol­ecular structure of the title compound, showing the atom-numbering scheme. Displacement ellipsoids are drawn at the 30% probability level.

The asymmetric unit of the title compound, [SnBr2(C13H12N2)], contains an amidine ligand and tin(II) bromide. In the amidine ligand, the phenyl rings exhibit a head-to-tail configuration mode. The tin atom is coordinated by the terminal N atom of the amidine ligand, and the two Br atoms extend to both sides of Sn in a V-shape (Fig. 1[link]). The outward expansion configuration of the two bromine atoms is due to the large steric hindrance of the nearby substituents. The C2–C7 and C8–C13 phenyl rings are twisted from the N1/C1/N2 mean plane by 26.14 (18) and 79.50 (8)°, respectively. The two N atoms connect the central C atom with bond lengths of 1.315 (5) and 1.324 (5) Å, while the Sn—N bond length is 2.176 (3) and the Sn—Br bond lengths are 2.6286 (6) and 2.6313 (6) Å.

In the crystal, the mol­ecules are linked into chains along [100] by N—H⋯Br hydrogen bonds (Fig. 2[link], Table 1[link]).

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A D—H H⋯A DA D—H⋯A
N2—H2⋯Br1i 0.88 2.95 3.593 (4) 132
N2—H2⋯Br2i 0.88 2.77 3.517 (3) 144
Symmetry code: (i) x+1, y, z.
[Figure 2]
Figure 2
Part of the crystal structure, with hydrogen bonds drawn as dashed lines

Synthesis and crystallization

The title compound was prepared by a reaction of aniline, nBuLi, SiMe2Cl2, PhCN, SnCl2 and Br2. To a solution of aniline (2.328 g, 5 mmol) in diethyl ether (30 ml) were added nBuLi (2 ml, 2.5 M, 5 mmol) at 273 K and 0.5 equiv. of dimethyl di­chloro­silane (0.3 ml, 2.5 mmol) 3 h later; the solution was stirred overnight and filtered to remove the white LiCl precipitate. nBuLi (2 ml, 2.5 M, 5 mmol) was added again, then PhCN (0.5 ml, 5 mmol) was added by syringe in drops 4 h later. After stirring overnight, SnCl2 (0.474 g, 2.5 mmol) was added at 273 K and the solution was stirred for 12 h. Then the solvent was removed under vacuum followed by extraction with di­chloro­methane and filtration to remove the white LiCl precipitate. To the filtrate was added Br2 (0.13 ml, 2.52 mmol) and the solution was concentrated in vacuo to ca 15 ml about 24 h later. Colorless crystals (0.151 g, 76% yield) were obtained in toluene.

1H NMR (300 MHz, CDCl3): δ 6.59–7.68 (m, 11H; phenyl, C=N), 11.04 (s, 1H, C—N). 13C NMR(75 MHz, CDCl3): δ 122.03, 124.32, 124.68, 127.68, 128.21, 128.67, 130.08 (phenyls), Elemental analysis (calculated %) for C13H12Br2N2Sn: C, 30.81; H, 2.45; N, 6.09%. Found: C, 31.89; H, 2.55; N, 5.90%.

Refinement

Crystal data, data collection and structure refinement details are summarized in Table 2[link].

Table 2
Experimental details

Crystal data
Chemical formula [SnBr2(C13H12N2)]
Mr 474.76
Crystal system, space group Triclinic, P[\overline{1}]
Temperature (K) 200
a, b, c (Å) 8.0315 (11), 9.7147 (14), 10.7577 (15)
α, β, γ (°) 111.205 (4), 90.226 (5), 109.381 (4)
V3) 730.81 (18)
Z 2
Radiation type Mo Kα
μ (mm−1) 7.20
Crystal size (mm) 0.06 × 0.06 × 0.05
 
Data collection
Diffractometer Bruker SMART area-detector
Absorption correction Multi-scan (SADABS; Sheldrick, 1996[Sheldrick, G. M. (1996). SADABS. University of Göttingen, Germany.])
Tmin, Tmax 0.672, 0.715
No. of measured, independent and observed [I > 2σ(I)] reflections 7880, 2558, 2278
Rint 0.023
(sin θ/λ)max−1) 0.595
 
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.025, 0.055, 1.05
No. of reflections 2558
No. of parameters 164
H-atom treatment H-atom parameters constrained
Δρmax, Δρmin (e Å−3) 0.64, −0.57
Computer programs: SMART and SAINT (Bruker, 2000[Bruker (2000). SMART and SAINT. Bruker AXS Inc., Madison, Wisconsin, USA.]), SHELXS97 (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]) and SHELXL2014 (Sheldrick, 2015[Sheldrick, G. M. (2015). Acta Cryst. C71, 3-8.]).

Structural data


Computing details top

Data collection: SMART (Bruker, 2000); cell refinement: SAINT (Bruker, 2000); data reduction: SAINT (Bruker, 2000); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL2014 (Sheldrick, 2015); software used to prepare material for publication: SHELXL2014 (Sheldrick, 2015).

Dibromido(N-phenylbenzamidine-κN')tin(II) top
Crystal data top
[SnBr2(C13H12N2)]Z = 2
Mr = 474.76F(000) = 448
Triclinic, P1Dx = 2.157 Mg m3
a = 8.0315 (11) ÅMo Kα radiation, λ = 0.71073 Å
b = 9.7147 (14) ÅCell parameters from 5984 reflections
c = 10.7577 (15) Åθ = 2.9–28.3°
α = 111.205 (4)°µ = 7.20 mm1
β = 90.226 (5)°T = 200 K
γ = 109.381 (4)°Block, colorless
V = 730.81 (18) Å30.06 × 0.06 × 0.05 mm
Data collection top
Bruker SMART area-detector
diffractometer
2278 reflections with I > 2σ(I)
φ and ω scanRint = 0.023
Absorption correction: multi-scan
(SADABS; Sheldrick, 1996)
θmax = 25.0°, θmin = 2.9°
Tmin = 0.672, Tmax = 0.715h = 99
7880 measured reflectionsk = 1110
2558 independent reflectionsl = 1212
Refinement top
Refinement on F2Hydrogen site location: inferred from neighbouring sites
Least-squares matrix: fullH-atom parameters constrained
R[F2 > 2σ(F2)] = 0.025 w = 1/[σ2(Fo2) + (0.0169P)2 + 1.8927P]
where P = (Fo2 + 2Fc2)/3
wR(F2) = 0.055(Δ/σ)max = 0.001
S = 1.05Δρmax = 0.64 e Å3
2558 reflectionsΔρmin = 0.57 e Å3
164 parametersExtinction correction: SHELXL2014 (Sheldrick, 2015), Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4
0 restraintsExtinction coefficient: 0.0035 (4)
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
xyzUiso*/Ueq
Sn10.48568 (3)0.62191 (3)0.83884 (3)0.02458 (11)
Br10.26091 (5)0.38582 (5)0.88757 (5)0.03684 (14)
Br20.28771 (6)0.53282 (5)0.60875 (4)0.03595 (13)
N10.6254 (4)0.4638 (4)0.7385 (3)0.0280 (8)
H10.55920.36700.68470.034*
N20.8777 (4)0.3932 (4)0.7203 (4)0.0335 (8)
H20.99500.42870.73020.040*
C10.7990 (5)0.4990 (5)0.7505 (4)0.0272 (9)
C20.9223 (5)0.6672 (5)0.7996 (4)0.0259 (9)
C30.8896 (6)0.7654 (5)0.7439 (4)0.0314 (9)
H30.78850.72670.67810.038*
C41.0049 (6)0.9195 (5)0.7847 (4)0.0347 (10)
H40.98440.98700.74570.042*
C51.1505 (6)0.9767 (5)0.8821 (4)0.0337 (10)
H51.22981.08320.90960.040*
C61.1808 (5)0.8802 (5)0.9391 (4)0.0337 (10)
H61.28010.92061.00690.040*
C71.0680 (5)0.7248 (5)0.8987 (4)0.0294 (9)
H71.08930.65790.93800.035*
C80.7869 (5)0.2245 (5)0.6727 (4)0.0293 (9)
C90.8323 (6)0.1320 (5)0.5586 (5)0.0378 (11)
H90.91930.17960.51240.045*
C100.7519 (6)0.0305 (5)0.5106 (5)0.0396 (11)
H100.78580.09420.43240.048*
C110.6239 (6)0.1008 (5)0.5743 (5)0.0368 (11)
H110.56890.21260.54060.044*
C120.5753 (6)0.0076 (6)0.6882 (5)0.0415 (11)
H120.48470.05560.73180.050*
C130.6583 (6)0.1562 (5)0.7394 (5)0.0386 (11)
H130.62710.22020.81900.046*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
Sn10.02065 (15)0.02166 (15)0.02717 (17)0.00595 (11)0.00258 (11)0.00613 (12)
Br10.0261 (2)0.0444 (3)0.0472 (3)0.00800 (19)0.00491 (19)0.0299 (2)
Br20.0282 (2)0.0485 (3)0.0305 (3)0.0105 (2)0.00397 (18)0.0173 (2)
N10.0163 (16)0.0294 (18)0.033 (2)0.0086 (14)0.0015 (14)0.0061 (15)
N20.0177 (17)0.0324 (19)0.050 (2)0.0091 (15)0.0042 (15)0.0151 (17)
C10.029 (2)0.030 (2)0.022 (2)0.0103 (17)0.0048 (17)0.0093 (17)
C20.0183 (19)0.026 (2)0.025 (2)0.0056 (16)0.0083 (16)0.0036 (17)
C30.028 (2)0.037 (2)0.026 (2)0.0080 (18)0.0033 (17)0.0114 (19)
C40.045 (3)0.031 (2)0.030 (2)0.013 (2)0.007 (2)0.0142 (19)
C50.031 (2)0.025 (2)0.035 (3)0.0023 (18)0.0034 (19)0.0075 (19)
C60.023 (2)0.032 (2)0.034 (2)0.0039 (18)0.0029 (18)0.0048 (19)
C70.025 (2)0.030 (2)0.038 (3)0.0141 (17)0.0087 (18)0.0144 (19)
C80.028 (2)0.026 (2)0.034 (2)0.0109 (17)0.0025 (18)0.0104 (18)
C90.030 (2)0.039 (2)0.046 (3)0.013 (2)0.007 (2)0.017 (2)
C100.040 (3)0.030 (2)0.043 (3)0.017 (2)0.004 (2)0.004 (2)
C110.035 (2)0.026 (2)0.043 (3)0.0060 (19)0.011 (2)0.011 (2)
C120.037 (3)0.046 (3)0.049 (3)0.011 (2)0.004 (2)0.030 (2)
C130.044 (3)0.039 (3)0.037 (3)0.020 (2)0.008 (2)0.015 (2)
Geometric parameters (Å, º) top
Sn1—N12.176 (3)C5—H50.9500
Sn1—Br22.6286 (6)C6—C71.380 (6)
Sn1—Br12.6313 (6)C6—H60.9500
N1—C11.315 (5)C7—H70.9500
N1—H10.8800C8—C91.367 (6)
N2—C11.324 (5)C8—C131.385 (6)
N2—C81.441 (5)C9—C101.381 (6)
N2—H20.8800C9—H90.9500
C1—C21.492 (5)C10—C111.368 (7)
C2—C31.384 (6)C10—H100.9500
C2—C71.394 (6)C11—C121.381 (7)
C3—C41.376 (6)C11—H110.9500
C3—H30.9500C12—C131.392 (6)
C4—C51.383 (6)C12—H120.9500
C4—H40.9500C13—H130.9500
C5—C61.371 (6)
N1—Sn1—Br289.80 (9)C5—C6—C7120.5 (4)
N1—Sn1—Br187.49 (9)C5—C6—H6119.8
Br2—Sn1—Br190.618 (18)C7—C6—H6119.8
C1—N1—Sn1126.3 (3)C6—C7—C2119.1 (4)
C1—N1—H1116.8C6—C7—H7120.4
Sn1—N1—H1116.8C2—C7—H7120.4
C1—N2—C8125.3 (3)C9—C8—C13120.3 (4)
C1—N2—H2117.4C9—C8—N2117.8 (4)
C8—N2—H2117.4C13—C8—N2121.9 (4)
N1—C1—N2124.3 (4)C8—C9—C10120.0 (4)
N1—C1—C2120.4 (4)C8—C9—H9120.0
N2—C1—C2115.2 (3)C10—C9—H9120.0
C3—C2—C7120.4 (4)C11—C10—C9120.8 (4)
C3—C2—C1118.5 (4)C11—C10—H10119.6
C7—C2—C1121.1 (4)C9—C10—H10119.6
C4—C3—C2119.4 (4)C10—C11—C12119.4 (4)
C4—C3—H3120.3C10—C11—H11120.3
C2—C3—H3120.3C12—C11—H11120.3
C3—C4—C5120.4 (4)C11—C12—C13120.4 (4)
C3—C4—H4119.8C11—C12—H12119.8
C5—C4—H4119.8C13—C12—H12119.8
C6—C5—C4120.2 (4)C8—C13—C12119.1 (4)
C6—C5—H5119.9C8—C13—H13120.4
C4—C5—H5119.9C12—C13—H13120.4
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
N2—H2···Br1i0.882.953.593 (4)132
N2—H2···Br2i0.882.773.517 (3)144
Symmetry code: (i) x+1, y, z.
 

Funding information

Funding for this research was provided by: National Natural Science Foundation of China (award No. 20702029); Natural Science Foundation of Shanxi Province (award No. 2008011024).

References

First citationBai, S.-D., Tong, H.-B., Guo, J.-P., Zhou, M.-S., Liu, D.-S. & Yuan, S.-F. (2010). Polyhedron, 29, 262–269.  Web of Science CSD CrossRef CAS Google Scholar
First citationBruker (2000). SMART and SAINT. Bruker AXS Inc., Madison, Wisconsin, USA.  Google Scholar
First citationChlupatý, T., Růžičková, Z., Horáček, M., Alonso, M., De Proft, F., Kampová, H., Brus, J. & Růžička, A. (2015). Organometallics, 34, 606–615.  Google Scholar
First citationEdelmann, F. T. (1994). Coord. Chem. Rev. 137, 403–481.  CrossRef Web of Science Google Scholar
First citationSheldrick, G. M. (1996). SADABS. University of Göttingen, Germany.  Google Scholar
First citationSheldrick, G. M. (2008). Acta Cryst. A64, 112–122.  Web of Science CrossRef CAS IUCr Journals Google Scholar
First citationSheldrick, G. M. (2015). Acta Cryst. C71, 3–8.  Web of Science CrossRef IUCr Journals Google Scholar
First citationZhang, L.-Z. & Tong, H.-B. (2008). Acta Cryst. E64, o1276.  Web of Science CSD CrossRef IUCr Journals Google Scholar

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