Bis(μ-diethyl­phosphido-κ²P:P)bis­[bis(2,4,6-trimethyl­phen­yl)indium(III)]

The title compound, [In₂(C₉H₁₁)₄(C₄H₁₀P)₂], contains a centrosymmetric In₂P₂ core with short inter­molecular In—P bonds. This core has acute P—In—P and obtuse In—P—In bond angles compared with other [R₂InPR′₂]₂ analogues, due to the presence of the bulky aromatic substituents on the In atom and the non-sterically demanding ethyl substituents on the P atom.

Key indicators

• Single-crystal X-ray study
• T = 198 K
• Mean [sigma](C-C) = 0.005 Å
• R factor = 0.031
• wR factor = 0.078
• Data-to-parameter ratio = 21.2

checkCIF/PLATON results

No syntax errors found



Alert level C
PLAT250_ALERT_2_C Large U3/U1 Ratio for Average U(i,j) Tensor ....        2.2
PLAT912_ALERT_4_C Missing # of FCF Reflections Above STh/L=  0.600        138

Alert level G
PLAT005_ALERT_5_G No _iucr_refine_instructions_details in CIF ....          ?
PLAT380_ALERT_4_G Check Incorrectly? Oriented X(sp2)-Methyl Moiety        C16

   0 ALERT level A = Most likely a serious problem - resolve or explain
   0 ALERT level B = A potentially serious problem, consider carefully
   2 ALERT level C = Check. Ensure it is not caused by an omission or oversight
   2 ALERT level G = General information/check it is not something unexpected

   0 ALERT type 1 CIF construction/syntax error, inconsistent or missing data
   1 ALERT type 2 Indicator that the structure model may be wrong or deficient
   0 ALERT type 3 Indicator that the structure quality may be low
   2 ALERT type 4 Improvement, methodology, query or suggestion
   1 ALERT type 5 Informative message, check

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S1. Comment

Phosphanylindanes [R₂InPR'₂]_n form dimeric or trimeric structures in the solid state via intermolecular In—P coordinate bonding interactions (Beachley et al., 2001; Werner & Neumuller 1996). Dimeric structures feature distorted tetrahedral geometries at indium and phosphorus, and planar four-membered In₂P₂ ring cores. In—P bond distances within the ring are similar and differ by less than 0.05 Å in all reported structures (Wells et al., 1993). The structure of I (Fig. 1) shows a dimer in the solid state, with a characteristic In₂P₂ core and distorted tetrahedral geometries at the four coordinate indium and phosphorus centres. The In—P bond distances are similar [In—P = 2.6300 (12) Å, In—Pⁱ = 2.6364 (9) Å] and are in the range for previously reported dimeric phosphanylindanes [2.612 (1)–2.712 (1) Å] (Wells et al., 1993; Beachley et al., 1993). However, the ring P—In—Pⁱ bond angle [81.56 (3)°] is at the lower limit of the range of reported values for [R₂InPR'₂]₂ structures [81.80 (7)–87.53 (3)°] (Beachley et al., 1987; von Hanisch, 2001), and the In—P—Inⁱ bond angle [98.44 (3)°] is at the upper limit of reported values [92.47 (3)–98.20 (7)°] (von Hanisch, 2001; Beachley et al., 1987). The significant distortion of the In₂P₂ ring is likely a result of the bulky mesityl groups on indium, which affect a compression of the P—In—Pⁱ bond angles. Conversely, the non-bulky ethyl groups on phosphorus allows for expansion of the In—P—Inⁱ bond angles.

Related literature

For related dimeric phosphanylindanes, see: Alcock et al. (1989); Wells et al. (1992); Aitchison et al. (1989); Beachley et al. (1987, 1993, 1995, 2001); Culp et al. (1997); Malik et al. (1996); Thomas et al. (2002); Wells et al. (1993); von Hanisch (2001). For related trimeric phosphanylindanes, see: Burns et al. (1994); Werner & Neumuller (1996); Banks et al. (1991).

S2. Experimental

Preparation of [(2,4,6-Me₃C₆H₂)₂InPEt₂]₂ (I). Trismesityl indium (0.520 g, 1.10 mmol) was added to a solution of diethyl phosphine (0.100 g, 1.10 mmol) in toluene (7.5 ml). The reaction mixture was stirred at 45°C for 72 h, after which time a white precipitate had formed. The precipitate was removed by filtration, dried in vacuo, and washed with toluene (2 × 5 ml) and hexane (3 ml) (yield 0.110 g, 22%). Mp: 188°C. Crystals of I were obtained by dissolving the product in dichloromethane and allowing the solution to sit at 23°C for 12 h.

S3. Refinement

H atoms were included in calculated positions and refined using a riding model.

Computing details

Data collection: SMART (Bruker, 1999); cell refinement: SMART (Bruker, 1999); data reduction: SAINT (Bruker, 2006); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008b); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008b); molecular graphics: DIAMOND (Brandenburg, 2011); software used to prepare material for publication: SHELXTL (Sheldrick, 2008b).

Figures

Fig. 1. X-ray crystal structure of (I), with displacement ellipsoids drawn at the 50% probability level. H atoms have been omitted for clarity. Symmetry transformations used to generate equivalent atoms: (i) -x + 1/2, -y + 1/2, -z + 1. Selected bond distances (Å) and angles (°): In—P 2.6300 (12), In—P^i 2.6364 (9), In—C1 2.190 (3), In—C10 2.215 (3), P—C19 1.866 (3), P—C21 1.856 (3), P—In—P^i 81.56 (3), In—P—In^i 98.44 (3), C1—In—C10 117.6 (1), C19—P—C21 104.4 (2).

Bis(µ-diethylphosphido-κ²P:P)bis[bis(2,4,6- trimethylphenyl)indium(III)]

Crystal data

[In2(C9H11)4(C4H10P)2]	F(000) = 1824
Mr = 884.53	Dx = 1.377 Mg m^−3
Monoclinic, C2/c	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -C 2yc	Cell parameters from 6933 reflections
a = 22.323 (4) Å	θ = 2.7–28.1°
b = 15.494 (4) Å	µ = 1.18 mm^−1
c = 14.331 (3) Å	T = 198 K
β = 120.618 (4)°	Plate, colourless
V = 4265.6 (17) Å^3	0.23 × 0.20 × 0.01 mm
Z = 4

Data collection

Bruker SMART1000/P4 diffractometer	4771 independent reflections
Radiation source: fine-focus sealed tube, K760	3470 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.038
ϕ and ω scans	θmax = 27.5°, θmin = 1.7°
Absorption correction: multi-scan (SADABS; Sheldrick, 2008a)	h = −28→27
Tmin = 0.777, Tmax = 0.988	k = −19→19
14538 measured reflections	l = −18→18

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)] = 0.031	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.078	H-atom parameters constrained
S = 1.09	w = 1/[σ^2(Fo^2) + (0.0318P)^2 + 1.4614P] where P = (Fo^2 + 2Fc^2)/3
4771 reflections	(Δ/σ)max = 0.001
225 parameters	Δρmax = 0.65 e Å^−3
0 restraints	Δρmin = −0.34 e Å^−3

Special details

Experimental. Crystal decay was monitored by repeating the initial 50 frames at the end of the data collection and analyzing duplicate reflections

NMR data (p.p.m., CDCl₃): ¹H NMR, 0.88 (m, 6H, PCH₂CH₃), 1.83 (q, ³J(¹H-¹H) = 7 Hz, 4H, PCH₂CH₃), 2.24 (s, 6H, 2,4,6-Me₃C₆H₂), 2.33 (s, 12H, 2,4,6-Me₃C₆H₂), 6.78 (s, 4H, 2,4,6-Me₃C₆H₂); ¹³C{¹H}11.7 (PCH₂CH₃), 13.8 (PCH₂CH₃), 21.3 (s, 2,4,6-Me₃C₆H₂), 27.7 (s, 2,4,6-Me₃C₆H₂), 126.8 (s, 2,4,6-Me₃C₆H₂), 136.6 (s, 2,4,6-Me₃C₆H₂), 144.1 (s, 2,4,6-Me₃C₆H₂); ³¹P NMR, δ -44.63 (s). FT—IR: 538m, 607vw, 673w, 708w, 752w, 800w, 845m, 976w, 1030w, 1042w, 1090w, 1149vw, 1244w, 1259w, 1288w, 1402w, 1547w, 1595vw, 1712vw.

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
In1	0.231901 (11)	0.163644 (15)	0.585903 (16)	0.03479 (8)
P1	0.21902 (4)	0.33051 (6)	0.54684 (6)	0.03532 (19)
C1	0.14507 (16)	0.0724 (2)	0.5087 (2)	0.0355 (7)
C2	0.07490 (17)	0.0952 (2)	0.4400 (2)	0.0430 (8)
C3	0.02405 (18)	0.0319 (3)	0.3942 (3)	0.0504 (9)
H3	−0.0230	0.0488	0.3476	0.061*
C4	0.03963 (19)	−0.0550 (3)	0.4142 (3)	0.0512 (10)
C5	0.10908 (19)	−0.0781 (2)	0.4811 (3)	0.0466 (9)
H5	0.1210	−0.1375	0.4954	0.056*
C6	0.16177 (17)	−0.0161 (2)	0.5276 (2)	0.0381 (8)
C7	0.0530 (2)	0.1886 (3)	0.4137 (3)	0.0607 (11)
H7A	0.0020	0.1922	0.3735	0.091*
H7B	0.0710	0.2124	0.3695	0.091*
H7C	0.0716	0.2216	0.4812	0.091*
C8	−0.0172 (2)	−0.1223 (3)	0.3645 (4)	0.0719 (13)
H8A	−0.0539	−0.1079	0.3803	0.108*
H8B	0.0023	−0.1790	0.3951	0.108*
H8C	−0.0369	−0.1236	0.2858	0.108*
C9	0.23652 (17)	−0.0451 (2)	0.5954 (3)	0.0464 (8)
H9A	0.2378	−0.1068	0.6114	0.070*
H9B	0.2595	−0.0124	0.6634	0.070*
H9C	0.2607	−0.0350	0.5553	0.070*
C10	0.30035 (17)	0.1564 (2)	0.7643 (2)	0.0394 (8)
C11	0.37154 (17)	0.1357 (2)	0.8185 (2)	0.0427 (8)
C12	0.41094 (19)	0.1333 (2)	0.9321 (3)	0.0512 (9)
H12	0.4590	0.1193	0.9670	0.061*
C13	0.3812 (2)	0.1508 (2)	0.9945 (3)	0.0541 (10)
C14	0.3113 (2)	0.1726 (2)	0.9417 (3)	0.0520 (10)
H14	0.2903	0.1858	0.9834	0.062*
C15	0.27101 (18)	0.1755 (2)	0.8287 (3)	0.0437 (8)
C16	0.40779 (19)	0.1146 (3)	0.7567 (3)	0.0576 (10)
H16A	0.3855	0.0644	0.7102	0.086*
H16B	0.4569	0.1016	0.8080	0.086*
H16C	0.4046	0.1642	0.7119	0.086*
C17	0.4242 (2)	0.1459 (3)	1.1178 (3)	0.0770 (14)
H17A	0.4729	0.1341	1.1407	0.115*
H17B	0.4062	0.0994	1.1433	0.115*
H17C	0.4210	0.2009	1.1488	0.115*
C18	0.19456 (18)	0.1971 (3)	0.7786 (3)	0.0541 (10)
H18A	0.1883	0.2598	0.7698	0.081*
H18B	0.1779	0.1764	0.8260	0.081*
H18C	0.1680	0.1692	0.7076	0.081*
C19	0.29184 (17)	0.3701 (2)	0.6794 (2)	0.0414 (8)
H19A	0.2829	0.3512	0.7371	0.050*
H19B	0.3352	0.3416	0.6930	0.050*
C20	0.30422 (19)	0.4667 (2)	0.6901 (3)	0.0496 (9)
H20A	0.3211	0.4852	0.6421	0.074*
H20B	0.3390	0.4808	0.7653	0.074*
H20C	0.2605	0.4965	0.6698	0.074*
C21	0.14350 (17)	0.3982 (2)	0.5211 (3)	0.0441 (8)
H21A	0.1544	0.4590	0.5144	0.053*
H21B	0.1031	0.3809	0.4505	0.053*
C22	0.12205 (18)	0.3937 (3)	0.6068 (3)	0.0527 (9)
H22A	0.1039	0.3360	0.6063	0.079*
H22B	0.0859	0.4369	0.5905	0.079*
H22C	0.1626	0.4053	0.6785	0.079*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
In1	0.02880 (13)	0.04999 (15)	0.01987 (11)	−0.01078 (11)	0.00826 (9)	0.00045 (10)
P1	0.0310 (4)	0.0489 (5)	0.0237 (4)	−0.0081 (4)	0.0122 (3)	−0.0014 (4)
C1	0.0328 (17)	0.053 (2)	0.0194 (14)	−0.0126 (15)	0.0121 (13)	−0.0020 (14)
C2	0.0355 (19)	0.059 (2)	0.0300 (17)	−0.0130 (17)	0.0137 (15)	−0.0048 (16)
C3	0.0330 (19)	0.070 (3)	0.043 (2)	−0.0120 (18)	0.0159 (16)	−0.0112 (18)
C4	0.042 (2)	0.071 (3)	0.046 (2)	−0.026 (2)	0.0267 (18)	−0.0234 (19)
C5	0.057 (2)	0.050 (2)	0.045 (2)	−0.0126 (18)	0.0349 (19)	−0.0124 (16)
C6	0.0377 (18)	0.054 (2)	0.0261 (15)	−0.0101 (16)	0.0188 (14)	−0.0049 (14)
C7	0.038 (2)	0.068 (3)	0.052 (2)	−0.0092 (19)	0.0052 (18)	0.0079 (19)
C8	0.061 (3)	0.085 (3)	0.077 (3)	−0.038 (2)	0.040 (2)	−0.035 (3)
C9	0.045 (2)	0.053 (2)	0.0365 (19)	−0.0034 (18)	0.0176 (17)	0.0005 (16)
C10	0.0374 (18)	0.050 (2)	0.0220 (15)	−0.0155 (16)	0.0089 (13)	0.0015 (14)
C11	0.0372 (19)	0.057 (2)	0.0255 (16)	−0.0129 (16)	0.0098 (14)	0.0013 (14)
C12	0.038 (2)	0.068 (2)	0.0303 (18)	−0.0126 (18)	0.0045 (15)	0.0032 (16)
C13	0.056 (2)	0.069 (3)	0.0236 (17)	−0.021 (2)	0.0109 (16)	0.0005 (16)
C14	0.053 (2)	0.072 (3)	0.0273 (17)	−0.018 (2)	0.0175 (16)	−0.0053 (17)
C15	0.0394 (19)	0.058 (2)	0.0277 (16)	−0.0146 (17)	0.0128 (14)	0.0006 (15)
C16	0.040 (2)	0.091 (3)	0.0348 (19)	−0.004 (2)	0.0141 (17)	0.002 (2)
C17	0.072 (3)	0.112 (4)	0.0230 (18)	−0.021 (3)	0.0070 (18)	0.002 (2)
C18	0.044 (2)	0.080 (3)	0.039 (2)	−0.007 (2)	0.0216 (18)	0.0019 (18)
C19	0.0381 (19)	0.058 (2)	0.0238 (16)	−0.0072 (16)	0.0126 (14)	−0.0021 (14)
C20	0.055 (2)	0.060 (2)	0.0350 (19)	−0.0194 (19)	0.0234 (17)	−0.0112 (16)
C21	0.0364 (19)	0.057 (2)	0.0365 (18)	−0.0003 (17)	0.0165 (15)	0.0003 (16)
C22	0.041 (2)	0.078 (3)	0.0373 (19)	−0.004 (2)	0.0193 (17)	−0.0078 (18)

Geometric parameters (Å, º)

In1—C1	2.190 (3)	C11—C16	1.509 (5)
In1—C10	2.215 (3)	C12—C13	1.385 (5)
In1—P1	2.6300 (12)	C12—H12	0.9500
In1—P1^i	2.6364 (9)	C13—C14	1.386 (5)
P1—C21	1.856 (3)	C13—C17	1.524 (5)
P1—C19	1.866 (3)	C14—C15	1.397 (4)
P1—In1^i	2.6364 (9)	C14—H14	0.9500
C1—C2	1.406 (4)	C15—C18	1.514 (5)
C1—C6	1.409 (5)	C16—H16A	0.9800
C2—C3	1.386 (5)	C16—H16B	0.9800
C2—C7	1.512 (5)	C16—H16C	0.9800
C3—C4	1.384 (5)	C17—H17A	0.9800
C3—H3	0.9500	C17—H17B	0.9800
C4—C5	1.392 (5)	C17—H17C	0.9800
C4—C8	1.511 (5)	C18—H18A	0.9800
C5—C6	1.398 (4)	C18—H18B	0.9800
C5—H5	0.9500	C18—H18C	0.9800
C6—C9	1.510 (4)	C19—C20	1.515 (5)
C7—H7A	0.9800	C19—H19A	0.9900
C7—H7B	0.9800	C19—H19B	0.9900
C7—H7C	0.9800	C20—H20A	0.9800
C8—H8A	0.9800	C20—H20B	0.9800
C8—H8B	0.9800	C20—H20C	0.9800
C8—H8C	0.9800	C21—C22	1.530 (4)
C9—H9A	0.9800	C21—H21A	0.9900
C9—H9B	0.9800	C21—H21B	0.9900
C9—H9C	0.9800	C22—H22A	0.9800
C10—C11	1.405 (5)	C22—H22B	0.9800
C10—C15	1.408 (5)	C22—H22C	0.9800
C11—C12	1.402 (4)
C1—In1—C10	117.60 (11)	C13—C12—C11	121.4 (3)
C1—In1—P1	123.68 (9)	C13—C12—H12	119.3
C10—In1—P1	103.40 (9)	C11—C12—H12	119.3
C1—In1—P1^i	104.11 (7)	C12—C13—C14	118.2 (3)
C10—In1—P1^i	122.61 (9)	C12—C13—C17	120.9 (4)
P1—In1—P1^i	81.56 (3)	C14—C13—C17	120.9 (4)
C21—P1—C19	104.40 (16)	C13—C14—C15	121.4 (3)
C21—P1—In1	125.97 (11)	C13—C14—H14	119.3
C19—P1—In1	99.36 (11)	C15—C14—H14	119.3
C21—P1—In1^i	120.44 (11)	C14—C15—C10	120.9 (3)
C19—P1—In1^i	104.85 (10)	C14—C15—C18	117.5 (3)
In1—P1—In1^i	98.44 (3)	C10—C15—C18	121.6 (3)
C2—C1—C6	118.1 (3)	C11—C16—H16A	109.5
C2—C1—In1	125.1 (2)	C11—C16—H16B	109.5
C6—C1—In1	116.8 (2)	H16A—C16—H16B	109.5
C3—C2—C1	120.3 (3)	C11—C16—H16C	109.5
C3—C2—C7	118.4 (3)	H16A—C16—H16C	109.5
C1—C2—C7	121.3 (3)	H16B—C16—H16C	109.5
C4—C3—C2	122.1 (3)	C13—C17—H17A	109.5
C4—C3—H3	119.0	C13—C17—H17B	109.5
C2—C3—H3	119.0	H17A—C17—H17B	109.5
C3—C4—C5	117.9 (3)	C13—C17—H17C	109.5
C3—C4—C8	120.8 (4)	H17A—C17—H17C	109.5
C5—C4—C8	121.3 (4)	H17B—C17—H17C	109.5
C4—C5—C6	121.5 (3)	C15—C18—H18A	109.5
C4—C5—H5	119.3	C15—C18—H18B	109.5
C6—C5—H5	119.3	H18A—C18—H18B	109.5
C5—C6—C1	120.1 (3)	C15—C18—H18C	109.5
C5—C6—C9	119.1 (3)	H18A—C18—H18C	109.5
C1—C6—C9	120.8 (3)	H18B—C18—H18C	109.5
C2—C7—H7A	109.5	C20—C19—P1	116.6 (2)
C2—C7—H7B	109.5	C20—C19—H19A	108.1
H7A—C7—H7B	109.5	P1—C19—H19A	108.1
C2—C7—H7C	109.5	C20—C19—H19B	108.1
H7A—C7—H7C	109.5	P1—C19—H19B	108.1
H7B—C7—H7C	109.5	H19A—C19—H19B	107.3
C4—C8—H8A	109.5	C19—C20—H20A	109.5
C4—C8—H8B	109.5	C19—C20—H20B	109.5
H8A—C8—H8B	109.5	H20A—C20—H20B	109.5
C4—C8—H8C	109.5	C19—C20—H20C	109.5
H8A—C8—H8C	109.5	H20A—C20—H20C	109.5
H8B—C8—H8C	109.5	H20B—C20—H20C	109.5
C6—C9—H9A	109.5	C22—C21—P1	116.1 (2)
C6—C9—H9B	109.5	C22—C21—H21A	108.3
H9A—C9—H9B	109.5	P1—C21—H21A	108.3
C6—C9—H9C	109.5	C22—C21—H21B	108.3
H9A—C9—H9C	109.5	P1—C21—H21B	108.3
H9B—C9—H9C	109.5	H21A—C21—H21B	107.4
C11—C10—C15	117.3 (3)	C21—C22—H22A	109.5
C11—C10—In1	124.8 (2)	C21—C22—H22B	109.5
C15—C10—In1	117.9 (2)	H22A—C22—H22B	109.5
C12—C11—C10	120.8 (3)	C21—C22—H22C	109.5
C12—C11—C16	118.0 (3)	H22A—C22—H22C	109.5
C10—C11—C16	121.2 (3)	H22B—C22—H22C	109.5

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