A 1:1 adduct between bis­(chloro­di­methyl­stannyl)­methane and hexa­methyl­phospho­ric acid tri­amide (HMPA)

In the title compound, [Sn₂(CH₂)(CH₃)₄Cl₂]·C₆H₁₈N₃OP, the mol­ecule lies on a mirror plane. The two pentacoordinated Sn atoms are part of a planar four-membered —C—Sn...Cl—Sn— ring [Sn—C 2.103 (4) and 2.093 (4), Sn—Cl 2.6333 (11) and Sn...Cl 3.0369 (12) Å; Sn—C—Sn 115.8 (2)°].

Key indicators

• Single-crystal X-ray study
• T = 291 K
• Mean [sigma](N-C) = 0.004 Å
• R factor = 0.027
• wR factor = 0.063
• Data-to-parameter ratio = 25.2

checkCIF results

No syntax errors found

ADDSYM reports no extra symmetry

---

S1. Comment

Although bis(chlorodimethylstannyl)methane is a potential acceptor for either one or two monodentate ligands, only 1:1 adducts have so far been described. Two types of coordination are known: either both Sn atoms undergo bonding in such a way that the ligand bridges the two Sn atoms, as in the case of dimethyl sulfoxide (Mandolesi et al., 2001), both Sn atoms thus increasing coordination number to five, or only one Sn atom undergoes coordination, as in the case of pyridine (Austin et al., 1987). In the title compound, HMPA bonds via O to give a structure completely analogous to the 1:1 adduct formed by the nitrogen donor pyridine. The ligand is complexed to one Sn atom site to form an almost perfect trigonal bipyramid. Cl1 does however interact with Sn2, the distance between these atoms being 3.0369 (12) Å [pyridine: 3.009 (3) Å], so that Sn2 also has a distorted trigonal bipyramidal geometry (angle Cl1—Sn2—Cl2 176.98 (4) ° [pyridine 176.3 (1) °]). The Sn—Cl bond lengths are very different {Sn2—Cl2 2.4403 (12) Å [pyridine 2.468 (2) Å and Sn1—Cl1 2.6333 (11) Å [pyridine 2.638 (3) Å]}. A further similaritie between (I) and the pyridine adduct, is the bond angle O1—Sn1—Cl1 [176.27 (8)° in (I) cf. 175.4 (2)° in pyridine]. Atoms Sn1, Cl1, C3, Sn2, Cl2, O1, P1 and N1 lie on a mirror plane.

S2. Experimental

0.3 g (0.73 mmol) of 2,2-bis(chlorodimethylstannyl)propane (Austin et al., 1987; Karol et al., 1983) was dissolved in 2 ml of dry HMPA and the mixture stirred for 30 min. The solution was left overnight at 287–288 K. The crystals were separated and dried very carefully to remove the solvent from their surface; m.p. 407–410 K, yield 56%.

S3. Refinement

H atoms were placed in calculated positions, with U_iso constrained to be 1.5 times U_eq of the carrier atom for the methyl-H and 1.2 times U_eq for the remaining H atoms. The methyl groups were allowed to rotate but not to tip.

Computing details

Data collection: COLLECT (Nonius, 1998); cell refinement: DENZO and SCALEPACK (Otwinowski & Minor, 1997); data reduction: DENZO and SCALEPACK; program(s) used to solve structure: SHELXS97 (Sheldrick, 1990); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: SHELXTL-Plus (Sheldrick, 1991); software used to prepare material for publication: SHELXL97, PARST95 (Nardelli, 1995), PLATON (Spek, 2001).

Figures

Fig. 1. : View of the title compound, showing the labelling scheme. Displacement ellipsoids are shown at the 30% probability level. H atoms have been omitted. [Symmetry code: (i) x, 1/2 − y, z.]

(I)

Crystal data

[Sn2(CH2)(CH3)4Cl2]·C6H18N3OP	F(000) = 1104
Mr = 561.65	Dx = 1.637 Mg m^−3
Orthorhombic, Pnma	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ac 2n	Cell parameters from 14378 reflections
a = 12.7116 (3) Å	θ = 3.2–27.5°
b = 12.4934 (3) Å	µ = 2.50 mm^−1
c = 14.3478 (3) Å	T = 291 K
V = 2278.59 (9) Å^3	Block, colourless
Z = 4	0.19 × 0.13 × 0.13 mm

Data collection

Nonius KappaCCD diffractometer	1915 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tube	Rint = 0.031
Graphite monochromator	θmax = 27.5°, θmin = 3.2°
Detector resolution: 19 vertical, 18 horizontal pixels mm^-1	h = −16→16
200 frames via ω–rotation (Δω=1°) and two times 20 s per frame (two sets at different κ–angles) scans	k = −16→16
14378 measured reflections	l = −18→18
2727 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)] = 0.028	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.063	H-atom parameters constrained
S = 0.96	w = 1/[σ^2(Fo^2) + (0.0298P)^2] where P = (Fo^2 + 2Fc^2)/3
2727 reflections	(Δ/σ)max < 0.001
108 parameters	Δρmax = 0.40 e Å^−3
0 restraints	Δρmin = −0.40 e Å^−3

Special details

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	Occ. (<1)
Sn1	0.21628 (2)	0.2500	0.077044 (17)	0.05681 (11)
Sn2	−0.06152 (2)	0.2500	0.048315 (19)	0.06293 (12)
Cl1	0.08251 (9)	0.2500	0.21718 (8)	0.1145 (6)
Cl2	−0.16903 (10)	0.2500	−0.09260 (8)	0.1054 (5)
P1	0.42450 (7)	0.2500	−0.09331 (7)	0.0471 (2)
O1	0.3201 (2)	0.2500	−0.04734 (18)	0.0765 (8)
N1	0.43418 (17)	0.13894 (19)	−0.15287 (17)	0.0675 (7)
N2	0.5279 (2)	0.2500	−0.0270 (2)	0.0540 (7)
C1	0.2817 (3)	0.1031 (4)	0.1193 (3)	0.1417 (19)
H1A	0.2268	0.0566	0.1409	0.213*
H1B	0.3311	0.1153	0.1688	0.213*
H1C	0.3172	0.0705	0.0675	0.213*
C2	−0.1172 (5)	0.1057 (5)	0.1036 (4)	0.190 (3)
H2B	−0.0587	0.0618	0.1218	0.285*
H2C	−0.1581	0.0689	0.0574	0.285*
H2D	−0.1603	0.1202	0.1571	0.285*
C3	0.0870 (3)	0.2500	−0.0145 (3)	0.0933 (18)
H3A	0.0922	0.3126	−0.0543	0.112*	0.50
H3B	0.0922	0.1874	−0.0543	0.112*	0.50
C11	0.5271 (3)	0.1143 (3)	−0.2078 (3)	0.1061 (12)
H11A	0.5379	0.0382	−0.2087	0.159*
H11B	0.5873	0.1486	−0.1807	0.159*
H11C	0.5174	0.1397	−0.2704	0.159*
C12	0.3403 (3)	0.0817 (3)	−0.1832 (2)	0.1040 (13)
H12A	0.3539	0.0062	−0.1829	0.156*
H12B	0.3219	0.1040	−0.2451	0.156*
H12C	0.2832	0.0973	−0.1416	0.156*
C13	0.5671 (2)	0.1525 (3)	0.0171 (3)	0.0819 (10)
H13A	0.6417	0.1474	0.0080	0.123*
H13B	0.5333	0.0915	−0.0103	0.123*
H13C	0.5519	0.1547	0.0827	0.123*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Sn1	0.04825 (18)	0.0723 (2)	0.04984 (16)	0.000	−0.00032 (11)	0.000
Sn2	0.04753 (18)	0.0853 (2)	0.05598 (18)	0.000	0.00816 (12)	0.000
Cl1	0.0819 (9)	0.2134 (19)	0.0481 (6)	0.000	0.0139 (6)	0.000
Cl2	0.0661 (8)	0.1812 (15)	0.0689 (7)	0.000	−0.0077 (6)	0.000
P1	0.0431 (5)	0.0543 (6)	0.0440 (5)	0.000	0.0021 (4)	0.000
O1	0.0479 (16)	0.121 (3)	0.0610 (16)	0.000	0.0094 (13)	0.000
N1	0.0754 (17)	0.0616 (16)	0.0654 (14)	−0.0044 (12)	−0.0048 (12)	−0.0120 (13)
N2	0.0511 (18)	0.053 (2)	0.0578 (17)	0.000	−0.0083 (15)	0.000
C1	0.140 (4)	0.139 (4)	0.146 (4)	0.057 (3)	0.044 (3)	0.077 (3)
C2	0.177 (5)	0.214 (6)	0.179 (5)	−0.106 (5)	−0.062 (4)	0.113 (4)
C3	0.047 (2)	0.171 (6)	0.062 (3)	0.000	0.000 (2)	0.000
C11	0.128 (3)	0.097 (3)	0.094 (2)	0.032 (3)	0.022 (2)	−0.023 (2)
C12	0.135 (3)	0.080 (3)	0.097 (3)	−0.034 (2)	−0.037 (2)	−0.0062 (19)
C13	0.072 (2)	0.087 (3)	0.086 (2)	0.0040 (17)	−0.0198 (17)	0.021 (2)

Geometric parameters (Å, º)

Sn1—C3	2.103 (4)	C1—H1A	0.9600
Sn1—C1^i	2.104 (4)	C1—H1B	0.9600
Sn1—C1	2.104 (4)	C1—H1C	0.9600
Sn1—O1	2.220 (3)	C2—H2B	0.9600
Sn1—Cl1	2.6333 (11)	C2—H2C	0.9600
Sn2—C2^i	2.092 (5)	C2—H2D	0.9600
Sn2—C2	2.092 (5)	C3—H3A	0.9700
Sn2—C3	2.093 (4)	C3—H3B	0.9700
Sn2—Cl2	2.4403 (12)	C11—H11A	0.9600
Sn2—Cl1	3.0369 (12)	C11—H11B	0.9600
P1—O1	1.482 (3)	C11—H11C	0.9600
P1—N2	1.623 (3)	C12—H12A	0.9600
P1—N1	1.634 (2)	C12—H12B	0.9600
P1—N1^i	1.634 (2)	C12—H12C	0.9600
N1—C11	1.453 (4)	C13—H13A	0.9600
N1—C12	1.458 (4)	C13—H13B	0.9600
N2—C13^i	1.459 (3)	C13—H13C	0.9600
N2—C13	1.459 (3)
C3—Sn1—C1^i	119.27 (15)	Sn1—C1—H1B	109.5
C3—Sn1—C1	119.27 (15)	H1A—C1—H1B	109.5
C1^i—Sn1—C1	121.4 (3)	Sn1—C1—H1C	109.5
C3—Sn1—O1	87.84 (13)	H1A—C1—H1C	109.5
C1^i—Sn1—O1	89.81 (12)	H1B—C1—H1C	109.5
C1—Sn1—O1	89.81 (12)	Sn2—C2—H2B	109.5
C3—Sn1—Cl1	88.42 (12)	Sn2—C2—H2C	109.5
C1^i—Sn1—Cl1	92.02 (12)	H2B—C2—H2C	109.5
C1—Sn1—Cl1	92.02 (12)	Sn2—C2—H2D	109.5
O1—Sn1—Cl1	176.27 (8)	H2B—C2—H2D	109.5
C2^i—Sn2—C2	118.9 (4)	H2C—C2—H2D	109.5
C2^i—Sn2—C3	117.9 (2)	Sn2—C3—Sn1	115.8 (2)
C2—Sn2—C3	117.9 (2)	Sn2—C3—H3A	108.3
C2^i—Sn2—Cl2	97.17 (14)	Sn1—C3—H3A	108.3
C2—Sn2—Cl2	97.17 (14)	Sn2—C3—H3B	108.3
C3—Sn2—Cl2	98.54 (12)	Sn1—C3—H3B	108.3
C2^i—Sn2—Cl1	84.33 (14)	H3A—C3—H3B	107.4
C2—Sn2—Cl1	84.33 (14)	N1—C11—H11A	109.5
C3—Sn2—Cl1	78.44 (12)	N1—C11—H11B	109.5
Cl2—Sn2—Cl1	176.98 (4)	H11A—C11—H11B	109.5
Sn1—Cl1—Sn2	77.30 (3)	N1—C11—H11C	109.5
O1—P1—N2	117.66 (17)	H11A—C11—H11C	109.5
O1—P1—N1	107.47 (10)	H11B—C11—H11C	109.5
N2—P1—N1	104.22 (10)	N1—C12—H12A	109.5
O1—P1—N1^i	107.47 (10)	N1—C12—H12B	109.5
N2—P1—N1^i	104.22 (10)	H12A—C12—H12B	109.5
N1—P1—N1^i	116.21 (18)	N1—C12—H12C	109.5
P1—O1—Sn1	152.92 (17)	H12A—C12—H12C	109.5
C11—N1—C12	113.5 (3)	H12B—C12—H12C	109.5
C11—N1—P1	121.7 (2)	N2—C13—H13A	109.5
C12—N1—P1	120.7 (2)	N2—C13—H13B	109.5
C13^i—N2—C13	113.1 (3)	H13A—C13—H13B	109.5
C13^i—N2—P1	122.02 (17)	N2—C13—H13C	109.5
C13—N2—P1	122.02 (17)	H13A—C13—H13C	109.5
Sn1—C1—H1A	109.5	H13B—C13—H13C	109.5
C3—Sn1—Cl1—Sn2	0.0	N2—P1—N1—C12	148.8 (2)
C1^i—Sn1—Cl1—Sn2	119.23 (15)	N1^i—P1—N1—C12	−97.2 (3)
C1—Sn1—Cl1—Sn2	−119.23 (15)	O1—P1—N2—C13^i	−79.7 (3)
C2^i—Sn2—Cl1—Sn1	−120.0 (2)	N1—P1—N2—C13^i	161.4 (3)
C2—Sn2—Cl1—Sn1	120.0 (2)	N1^i—P1—N2—C13^i	39.1 (3)
C3—Sn2—Cl1—Sn1	0.0	O1—P1—N2—C13	79.7 (3)
N2—P1—O1—Sn1	0.0	N1—P1—N2—C13	−39.1 (3)
N1—P1—O1—Sn1	117.12 (10)	N1^i—P1—N2—C13	−161.4 (3)
N1^i—P1—O1—Sn1	−117.12 (10)	C2^i—Sn2—C3—Sn1	77.14 (18)
C3—Sn1—O1—P1	180.0	C2—Sn2—C3—Sn1	−77.14 (18)
C1^i—Sn1—O1—P1	60.70 (15)	Cl2—Sn2—C3—Sn1	180.0
C1—Sn1—O1—P1	−60.70 (15)	Cl1—Sn2—C3—Sn1	0.0
O1—P1—N1—C11	179.1 (3)	C1^i—Sn1—C3—Sn2	−91.43 (15)
N2—P1—N1—C11	−55.4 (3)	C1—Sn1—C3—Sn2	91.43 (15)
N1^i—P1—N1—C11	58.7 (3)	O1—Sn1—C3—Sn2	180.0
O1—P1—N1—C12	23.2 (3)	Cl1—Sn1—C3—Sn2	0.0

Symmetry code: (i) x, −y+1/2, z.