Tetra-bromidobis(dicyclo-hexyl-phosphane-κP)digallium(Ga-Ga).

The title compound, a Ga(II) dimer, [Ga(2)Br(4)(C(12)H(23)P)(2)], was synthesized by reaction of GaBr(THF)(n) (THF is tetra-hydro-furan) with dicyclo-hexyl-phosphine in toluene. At 150 K the crystallographically centrosymmetric molecule exhibits disorder in which one of the two independent cyclo-hexyl groups is modelled over two sites in a 62 (1):38 (1) ratio. In d(6)-benzene solution, the compound exhibits virtual C(2h) symmetry as determined by (1)H NMR. The coordination environment of the Ga(II) atom is distorted tetrahedral.

Related literature

For references related to the synthesis of the ‘GaBr’ precursor and to cluster formation, see: Schnoeckel (2010 ▶); Steiner et al. (2004 ▶). For other Ga—Ga containing compounds, see: Baker et al. (2003 ▶) (the analogous digallium tetra­iodide compound); Uhl et al. (1989 ▶) [the first-reported Ga(II) dimer compound].

Experimental

Crystal data

[Ga2Br4(C12H23P)2]

M = 855.63

Monoclinic,

a = 9.6095 (11) Å

b = 13.7083 (16) Å

c = 13.3305 (16) Å

β = 109.177 (2)°

V = 1658.6 (3) Å3

Z = 2

Mo Kα radiation

μ = 6.55 mm−1

T = 150 K

0.36 × 0.27 × 0.19 mm

Data collection

Bruker SMART APEX2 CCD area-detector diffractometer

Absorption correction: multi-scan SADABS (Sheldrick, 1996 ▶) T min = 0.185, T max = 0.288

24854 measured reflections

4842 independent reflections

4253 reflections with I > 2σ(I)

R int = 0.021

Refinement

R[F 2 > 2σ(F 2)] = 0.034

wR(F 2) = 0.068

S = 1.00

4842 reflections

168 parameters

60 restraints

H atoms treated by a mixture of independent and constrained refinement

Δρmax = 1.88 e Å−3

Δρmin = −0.94 e Å−3

Data collection: APEX2 (Bruker, 2010 ▶); cell refinement: SAINT (Bruker, 2010 ▶); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: XSHELL (Bruker, 2010 ▶); software used to prepare material for publication: APEX2.

Crystal structure: contains datablock(s) I, global. DOI: 10.1107/S1600536812035982/nk2174sup1.cif

Structure factors: contains datablock(s) I. DOI: 10.1107/S1600536812035982/nk2174Isup2.hkl

Additional supplementary materials: crystallographic information; 3D view; checkCIF report

[Ga2Br4(C12H23P)2]	F(000) = 844
Mr = 855.63	Dx = 1.713 Mg m−3
Monoclinic, P21/n	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2yn	Cell parameters from 12733 reflections
a = 9.6095 (11) Å	θ = 2.7–30.5°
b = 13.7083 (16) Å	µ = 6.55 mm−1
c = 13.3305 (16) Å	T = 150 K
β = 109.177 (2)°	Prism, colourless
V = 1658.6 (3) Å3	0.36 × 0.27 × 0.19 mm
Z = 2

Bruker SMART APEX2 CCD area-detector diffractometer	4842 independent reflections
Radiation source: fine-focus sealed tube	4253 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.021
Detector resolution: 8.333 pixels mm-1	θmax = 30.0°, θmin = 2.2°
φ and ω scans	h = −13→13
Absorption correction: multi-scan (SADABS; Sheldrick, 1996)	k = −19→19
Tmin = 0.185, Tmax = 0.288	l = −18→18
24854 measured reflections

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)] = 0.034	Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.068	H atoms treated by a mixture of independent and constrained refinement
S = 1.00	w = 1/[σ2(Fo2) + (0.01P)2 + 4.865P], P = (max(Fo2,0) + 2Fc2)/3
4842 reflections	(Δ/σ)max = 0.001
168 parameters	Δρmax = 1.88 e Å−3
60 restraints	Δρmin = −0.94 e Å−3

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.

	x	y	z	Uiso*/Ueq	Occ. (<1)
Ga1	0.43950 (3)	0.06462 (2)	0.53291 (2)	0.02724 (7)
Br1	0.58862 (3)	0.20359 (2)	0.60235 (3)	0.04156 (8)
Br2	0.33747 (4)	0.01282 (3)	0.66273 (3)	0.04888 (9)
P1	0.23183 (7)	0.14796 (5)	0.40942 (5)	0.02762 (13)
H1	0.274 (4)	0.225 (2)	0.368 (3)	0.043 (9)*
C11	0.0946 (13)	0.1955 (10)	0.4656 (12)	0.0339 (18)	0.620 (13)
H11	0.0698	0.1412	0.5069	0.041*	0.620 (13)
C12	−0.0495 (10)	0.2268 (7)	0.3805 (7)	0.0453 (18)	0.620 (13)
H12A	−0.0287	0.2777	0.3348	0.054*	0.620 (13)
H12B	−0.0943	0.1702	0.3353	0.054*	0.620 (13)
C13	−0.1573 (10)	0.2667 (8)	0.4336 (8)	0.066 (2)	0.620 (13)
H13A	−0.2484	0.2890	0.3782	0.080*	0.620 (13)
H13B	−0.1844	0.2139	0.4743	0.080*	0.620 (13)
C14	−0.0905 (13)	0.3506 (7)	0.5072 (9)	0.071 (3)	0.620 (13)
H14A	−0.0680	0.4049	0.4661	0.085*	0.620 (13)
H14B	−0.1619	0.3745	0.5408	0.085*	0.620 (13)
C15	0.0478 (13)	0.3180 (11)	0.5913 (9)	0.076 (3)	0.620 (13)
H15A	0.0234	0.2671	0.6355	0.092*	0.620 (13)
H15B	0.0918	0.3739	0.6380	0.092*	0.620 (13)
C16	0.1608 (11)	0.2771 (13)	0.5433 (12)	0.0610 (18)	0.620 (13)
H16A	0.1945	0.3300	0.5063	0.073*	0.620 (13)
H16B	0.2475	0.2522	0.6009	0.073*	0.620 (13)
C11A	0.114 (2)	0.2078 (18)	0.475 (2)	0.0339 (18)	0.380 (13)
H11A	0.0753	0.1557	0.5109	0.041*	0.380 (13)
C12A	−0.0197 (17)	0.2566 (12)	0.3935 (12)	0.0453 (18)	0.380 (13)
H12C	0.0143	0.3053	0.3518	0.054*	0.380 (13)
H12D	−0.0788	0.2068	0.3438	0.054*	0.380 (13)
C13A	−0.1153 (15)	0.3069 (13)	0.4503 (13)	0.066 (2)	0.380 (13)
H13C	−0.1967	0.3420	0.3972	0.080*	0.380 (13)
H13D	−0.1595	0.2568	0.4839	0.080*	0.380 (13)
C14A	−0.030 (2)	0.3779 (12)	0.5336 (14)	0.071 (3)	0.380 (13)
H14C	0.0048	0.4325	0.4992	0.085*	0.380 (13)
H14D	−0.0945	0.4051	0.5710	0.085*	0.380 (13)
C15A	0.100 (2)	0.3296 (19)	0.6123 (14)	0.076 (3)	0.380 (13)
H15C	0.0645	0.2810	0.6532	0.092*	0.380 (13)
H15D	0.1580	0.3792	0.6628	0.092*	0.380 (13)
C16A	0.2001 (18)	0.279 (2)	0.560 (2)	0.0610 (18)	0.380 (13)
H16C	0.2474	0.3281	0.5276	0.073*	0.380 (13)
H16D	0.2787	0.2429	0.6143	0.073*	0.380 (13)
C21	0.1299 (3)	0.0773 (2)	0.2924 (2)	0.0305 (5)
H21	0.0502	0.1198	0.2458	0.037*
C22	0.0573 (3)	−0.0116 (2)	0.3232 (3)	0.0414 (7)
H22A	0.1338	−0.0552	0.3695	0.050*
H22B	−0.0080	0.0095	0.3631	0.050*
C23	−0.0321 (4)	−0.0665 (3)	0.2234 (3)	0.0564 (9)
H23A	−0.0759	−0.1255	0.2437	0.068*
H23B	−0.1135	−0.0245	0.1801	0.068*
C24	0.0637 (4)	−0.0955 (3)	0.1588 (3)	0.0574 (10)
H24A	0.0021	−0.1279	0.0928	0.069*
H24B	0.1382	−0.1431	0.1997	0.069*
C25	0.1420 (4)	−0.0083 (3)	0.1301 (3)	0.0539 (9)
H25A	0.0682	0.0356	0.0818	0.065*
H25B	0.2088	−0.0315	0.0922	0.065*
C26	0.2313 (3)	0.0484 (2)	0.2299 (2)	0.0384 (6)
H26A	0.3128	0.0073	0.2746	0.046*
H26B	0.2744	0.1076	0.2093	0.046*

	U11	U22	U33	U12	U13	U23
Ga1	0.02597 (13)	0.02897 (14)	0.02464 (13)	0.00414 (11)	0.00541 (10)	−0.00146 (11)
Br1	0.04072 (16)	0.03471 (15)	0.04223 (16)	−0.00386 (12)	0.00408 (13)	−0.00738 (12)
Br2	0.04296 (17)	0.0654 (2)	0.04385 (18)	0.00912 (15)	0.02185 (14)	0.01749 (16)
P1	0.0278 (3)	0.0276 (3)	0.0266 (3)	0.0028 (2)	0.0077 (2)	0.0016 (2)
C11	0.036 (3)	0.033 (4)	0.035 (3)	0.011 (3)	0.014 (2)	0.005 (2)
C12	0.040 (4)	0.046 (5)	0.048 (3)	0.018 (3)	0.011 (3)	0.003 (3)
C13	0.052 (4)	0.075 (6)	0.076 (4)	0.035 (4)	0.026 (4)	0.008 (4)
C14	0.085 (7)	0.061 (5)	0.077 (6)	0.036 (5)	0.041 (5)	−0.001 (4)
C15	0.085 (8)	0.083 (5)	0.062 (5)	0.032 (6)	0.027 (4)	−0.023 (4)
C16	0.060 (5)	0.062 (3)	0.056 (5)	0.017 (5)	0.013 (4)	−0.023 (3)
C11A	0.036 (3)	0.033 (4)	0.035 (3)	0.011 (3)	0.014 (2)	0.005 (2)
C12A	0.040 (4)	0.046 (5)	0.048 (3)	0.018 (3)	0.011 (3)	0.003 (3)
C13A	0.052 (4)	0.075 (6)	0.076 (4)	0.035 (4)	0.026 (4)	0.008 (4)
C14A	0.085 (7)	0.061 (5)	0.077 (6)	0.036 (5)	0.041 (5)	−0.001 (4)
C15A	0.085 (8)	0.083 (5)	0.062 (5)	0.032 (6)	0.027 (4)	−0.023 (4)
C16A	0.060 (5)	0.062 (3)	0.056 (5)	0.017 (5)	0.013 (4)	−0.023 (3)
C21	0.0251 (11)	0.0354 (14)	0.0257 (12)	0.0027 (10)	0.0010 (9)	0.0005 (10)
C22	0.0356 (15)	0.0427 (17)	0.0425 (16)	−0.0079 (13)	0.0084 (13)	−0.0009 (13)
C23	0.0493 (19)	0.051 (2)	0.056 (2)	−0.0158 (17)	0.0010 (17)	−0.0079 (17)
C24	0.063 (2)	0.048 (2)	0.0420 (18)	−0.0013 (17)	−0.0084 (16)	−0.0148 (16)
C25	0.057 (2)	0.071 (2)	0.0271 (15)	0.0003 (18)	0.0041 (14)	−0.0121 (16)
C26	0.0348 (14)	0.0521 (18)	0.0259 (13)	−0.0001 (13)	0.0068 (11)	−0.0040 (12)

Ga1—Br2	2.3612 (5)	C15—H15A	0.9900
Ga1—Br1	2.3807 (5)	C15—H15B	0.9900
Ga1—P1	2.4164 (7)	C16—H16A	0.9900
Ga1—Ga1i	2.4353 (6)	C16—H16B	0.9900
P1—C21	1.824 (3)	C21—C22	1.526 (4)
P1—C11A	1.83 (2)	C21—C26	1.527 (4)
P1—C11	1.837 (13)	C21—H21	1.0000
P1—H1	1.31 (3)	C22—C23	1.523 (5)
C11—C16	1.516 (7)	C22—H22A	0.9900
C11—C12	1.535 (6)	C22—H22B	0.9900
C11—H11	1.0000	C23—C24	1.506 (6)
C12—C13	1.534 (7)	C23—H23A	0.9900
C12—H12A	0.9900	C23—H23B	0.9900
C12—H12B	0.9900	C24—C25	1.527 (6)
C13—C14	1.512 (10)	C24—H24A	0.9900
C13—H13A	0.9900	C24—H24B	0.9900
C13—H13B	0.9900	C25—C26	1.537 (4)
C14—C15	1.499 (9)	C25—H25A	0.9900
C14—H14A	0.9900	C25—H25B	0.9900
C14—H14B	0.9900	C26—H26A	0.9900
C15—C16	1.536 (7)	C26—H26B	0.9900
Br2—Ga1—Br1	107.306 (18)	C11—C16—C15	111.0 (7)
Br2—Ga1—P1	101.11 (2)	C11—C16—H16A	109.4
Br1—Ga1—P1	98.25 (2)	C15—C16—H16A	109.4
Br2—Ga1—Ga1i	114.05 (2)	C11—C16—H16B	109.4
Br1—Ga1—Ga1i	115.13 (2)	C15—C16—H16B	109.4
P1—Ga1—Ga1i	118.93 (2)	H16A—C16—H16B	108.0
C21—P1—C11	106.3 (4)	C22—C21—C26	111.7 (3)
C21—P1—Ga1	115.00 (9)	C22—C21—P1	111.0 (2)
C11—P1—Ga1	115.7 (4)	C26—C21—P1	110.16 (19)
C21—P1—H1	102.5 (15)	C22—C21—H21	107.9
C11—P1—H1	104.4 (16)	C26—C21—H21	107.9
Ga1—P1—H1	111.6 (15)	P1—C21—H21	107.9
C16—C11—C12	111.9 (5)	C23—C22—C21	109.6 (3)
C16—C11—P1	110.1 (8)	C23—C22—H22A	109.7
C12—C11—P1	113.1 (8)	C21—C22—H22A	109.7
C16—C11—H11	107.1	C23—C22—H22B	109.7
C12—C11—H11	107.1	C21—C22—H22B	109.7
P1—C11—H11	107.1	H22A—C22—H22B	108.2
C13—C12—C11	110.0 (6)	C24—C23—C22	110.7 (3)
C13—C12—H12A	109.7	C24—C23—H23A	109.5
C11—C12—H12A	109.7	C22—C23—H23A	109.5
C13—C12—H12B	109.7	C24—C23—H23B	109.5
C11—C12—H12B	109.7	C22—C23—H23B	109.5
H12A—C12—H12B	108.2	H23A—C23—H23B	108.1
C14—C13—C12	111.3 (6)	C23—C24—C25	112.4 (3)
C14—C13—H13A	109.4	C23—C24—H24A	109.1
C12—C13—H13A	109.4	C25—C24—H24A	109.1
C14—C13—H13B	109.4	C23—C24—H24B	109.1
C12—C13—H13B	109.4	C25—C24—H24B	109.1
H13A—C13—H13B	108.0	H24A—C24—H24B	107.9
C15—C14—C13	110.0 (6)	C24—C25—C26	111.1 (3)
C15—C14—H14A	109.7	C24—C25—H25A	109.4
C13—C14—H14A	109.7	C26—C25—H25A	109.4
C15—C14—H14B	109.7	C24—C25—H25B	109.4
C13—C14—H14B	109.7	C26—C25—H25B	109.4
H14A—C14—H14B	108.2	H25A—C25—H25B	108.0
C14—C15—C16	111.8 (6)	C21—C26—C25	109.2 (3)
C14—C15—H15A	109.2	C21—C26—H26A	109.8
C16—C15—H15A	109.2	C25—C26—H26A	109.8
C14—C15—H15B	109.2	C21—C26—H26B	109.8
C16—C15—H15B	109.2	C25—C26—H26B	109.8
H15A—C15—H15B	107.9	H26A—C26—H26B	108.3
Br2—Ga1—P1—C21	−99.72 (10)	P1—C11—C16—C15	−180.0 (11)
Br1—Ga1—P1—C21	150.72 (10)	C14—C15—C16—C11	−55.2 (13)
Ga1i—Ga1—P1—C21	25.94 (11)	C11—P1—C21—C22	−64.9 (6)
Br2—Ga1—P1—C11	24.9 (6)	Ga1—P1—C21—C22	64.5 (2)
Br1—Ga1—P1—C11	−84.6 (6)	C11A—P1—C21—C26	167.9 (11)
Ga1i—Ga1—P1—C11	150.6 (6)	C11—P1—C21—C26	170.9 (6)
C21—P1—C11—C16	−164.2 (8)	Ga1—P1—C21—C26	−59.8 (2)
Ga1—P1—C11—C16	66.8 (9)	C26—C21—C22—C23	−59.0 (3)
C21—P1—C11—C12	−38.2 (11)	P1—C21—C22—C23	177.6 (2)
Ga1—P1—C11—C12	−167.2 (7)	C21—C22—C23—C24	56.9 (4)
C16—C11—C12—C13	−54.2 (12)	C22—C23—C24—C25	−55.9 (4)
P1—C11—C12—C13	−179.3 (8)	C23—C24—C25—C26	55.1 (4)
C11—C12—C13—C14	56.9 (10)	C22—C21—C26—C25	57.8 (3)
C12—C13—C14—C15	−58.8 (10)	P1—C21—C26—C25	−178.3 (2)
C13—C14—C15—C16	57.5 (12)	C24—C25—C26—C21	−54.8 (4)
C12—C11—C16—C15	53.3 (13)

Ga1—Br2	2.3612 (5)
Ga1—Br1	2.3807 (5)
Ga1—P1	2.4164 (7)
Ga1—Ga1i	2.4353 (6)

Br2—Ga1—Br1	107.306 (18)
Br2—Ga1—P1	101.11 (2)
Br1—Ga1—P1	98.25 (2)
Br2—Ga1—Ga1i	114.05 (2)
Br1—Ga1—Ga1i	115.13 (2)
P1—Ga1—Ga1i	118.93 (2)

Symmetry code: (i) .