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Di-μ-pyridyl-1:2κ2N:C2;2:1κ2N:C2-μ-tetra­hydro­furan-κ2O:O-bis­­[bromo­(tetra­hydro­furan)magnesium(II)] tetra­hydro­furan hemisolvate

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aN. S. Kurnakov Institute of General and Inorganic Chemistry, Russian Academy of Science, 31 Leninskii Prospect, Moscow 119991, Russian Federation, bDepartment of Chemistry, Moscow State University, Leninskie Gory, Moscow 119992, Russian Federation, and cDepartment of Chemistry, University of Durham, Science Laboratories, South Road, Durham DH1 3LE, England
*Correspondence e-mail: churakov@igic.ras.ru

(Received 12 April 2006; accepted 16 April 2006; online 26 April 2006)

The title compound, [Mg2Br2(C5H4N)2(C4H8O)3]·0.5C4H8O, contains dimeric associations of Mg atoms bridged by tetra­hydro­furan (THF) mol­ecules. The coordination polyhedron of the Mg atom is a slightly distorted MgCNO2Br trigonal bipyramid with two THF mol­ecules in the axial positions. One O atom occupies a site with symmetry 2.

Comment

The main mol­ecule of the title Grignard reagent, (μ-C4H8O)[Br(C4H8O)(μ-η2-C,N—C5H4N-2)Mg]2, (I)[link] (Fig. 1[link]), is dimeric [Mg1⋯Mg1i = 3.3237 (18) Å; symmetry code: (i) −y, −x, [{1\over 2}] − z] and is generated by twofold symmetry with O2 lying on a twofold rotation axis. The coordination polyhedron of the Mg atom is a slightly distorted MgCNO2Br trigonal bipyramid (Table 1[link]) with two tetra­hydro­furan (THF) mol­ecules in the axial (ax) positions. Bromine, pyridyl N and C atoms occupy equatorial (eq) sites. The eq—Mg1—eq angles lie within the range 115.52 (11)–121.74 (8)° and the ax—Mg1—eq angles are close to 90° [83.16 (8)–95.07 (10)°].

[Scheme 1]

This coordination environment of Mg is rather characteristic for adducts of Grignard reagents with THF, as was observed for MeMgBr (Vallino, 1969[Vallino, M. (1969). J. Organomet. Chem. 20, 1-10.]) and EtMgCl (Toney & Stucky, 1971[Toney, J. & Stucky, G. D. (1971). J. Organomet. Chem. 28, 5-20.]). The Mg1—Br1, Mg1—O1 and Mg1—C1 bond lengths are normal and consistent with related structures (Cambridge Structural Database; Version 5.27 of January 2006; Allen, 2002[Allen, F. H. (2002). Acta Cryst. B58, 380-388.]). The Mg1—N1 distance in (I)[link] is close to that found previously for pyridyl substituted alkyl­magnesiumbromide [2.122 (4) Å; Al-Juaid et al., 2001[Al-Juaid, S. S., Avent, A. G., Eaborn, C., El-Hamruni, S. M., Hawkes, S. A., Hill, M. S., Hopman, M., Hitchcock, P. B. & Smith, J. D. (2001). J. Organomet. Chem. 631, 76-86.]].

The sum of valence angles around O1, 358.0°, corresponds to sp2-hybridization. Analysis of data in the CSD showed that the latter is common for structures with Hal—Mg(C)—O(THF, terminal) fragments where the sum of angles varies from 351.8 to 360.0°. The second (O2) THF mol­ecule is bridging and the Mg1—O2—Mg1i angle is 88.86 (10)° [symmetry code: (i) −y, −x, [1\over2]z]. As expected, the Mg—O2 bond length is much longer than Mg—O1.

To the best of our knowledge, (I)[link] is only the second example of an Mg complex with a bridging THF mol­ecule. Previously, the dinuclear complex [(THF)(η2-PhNCNPh)]2Mg2(μ-Cl)2(μ-THF), (II), was structurally investigated (Cotton et al., 1997[Cotton, F. A., Haefner, S. C., Matonic, J. H., Wang, X. & Murillo, C. A. (1997). Polyhedron, 16, 541-550.]); for comparison, the Mg—O(μ-THF) distances in (II) are 2.322 (6) and 2.357 (6) Å, while the Mg—O—Mg angle is 84.3 (2)°. However, the bridging THF ligand is well known in the structures of alkali and rare earth metals complexes; there are 70 entries in the CSD, of which 29 are Li derivatives.

Compound (I)[link] is the first structurally characterized example of an Mg complex with bridging (μ-C,N-pyridyl-2) ligands. However, this bridging ligand is common for di- and polynuclear complexes of other metals (110 entries in the CSD, of which 85 are compounds of 8B group metals).

In the dimeric structure of (I)[link], the Br atoms are terminal. In contrast, an analysis of the CSD demonstrates that in all previously investigated di- and polymeric structures of Grignard reagents, the halogen atoms serve as bridges forming [Mg2(μ-Hal)2] fragments (16 entries).

Previously, the synthesis of closely related Grignard reagents (2-pyrid­yl)MgX·2THF (X = Br and I) was reported and their unit-cell parameters were determined (Paradies, 1974[Paradies, H. H. (1974). Naturwissenschaften, 61, 168-169.]). However, no information on their mol­ecular structures was published.

The crystals of (I)[link] contain disordered solvent THF mol­ecules lying on a fourfold axis. These THF mol­ecules occupy the cavities between the main mol­ecules.

[Figure 1]
Figure 1
Mol­ecular structure of the main mol­ecule of (I)[link], showing 50% probability displacement ellipsoids with H atoms omitted for clarity. [Symmetry code: (i) −y, −x, [{1\over 2}]z.]

Experimental

The synthetic procedure for (I)[link] reported by Paradies & Görbing (1969[Paradies, H. H. & Görbing, M. (1969). Angew. Chem. 81, 293.]) was found to be non-reproducible. This fact was mentioned by Furukava et al. (1987[Furukava, N., Shibutani, T. & Fujihara, H. (1987). Tetrahedron Lett. 28, 5845-5848.]). Compound (I)[link] was prepared by treatment of i-PrMgBr with 2-brompyridine (Trécourt et al., 1999[Trécourt, F., Breton, G., Bonnet, V., Mongin, F., Marsais, F. & Queguiner, G. (1999). Tetrahedron Lett. 40, 4339-4342.]) and for the first time isolated in pure form (yield 58%). The crystals of (I)[link] decompose rapidly in open air.

Crystal data
  • [Mg2Br2(C5H4N)2(C4H8O)3]·0.5C4H8O

  • Mr = 616.99

  • Tetragonal, P 4/n c c

  • a = 17.3368 (3) Å

  • c = 18.8696 (4) Å

  • V = 5671.53 (18) Å3

  • Z = 8

  • Dx = 1.445 Mg m−3

  • Mo Kα radiation

  • μ = 2.93 mm−1

  • T = 120 (2) K

  • Block, colourless

  • 0.30 × 0.20 × 0.10 mm

Data collection
  • Bruker SMART 1K diffractometer

  • ω scans

  • Absorption correction: multi-scan (SADABS; Sheldrick, 1997[Sheldrick, G. M. (1997). SADABS, SHELXS97 and SHELXL97. University of Göttingen, Germany.]) Tmin = 0.473, Tmax = 0.758

  • 30363 measured reflections

  • 3108 independent reflections

  • 2022 reflections with I > 2σ(I)

  • Rint = 0.093

  • θmax = 27.0°

Refinement
  • Refinement on F2

  • R[F2 > 2σ(F2)] = 0.039

  • wR(F2) = 0.085

  • S = 1.00

  • 3108 reflections

  • 161 parameters

  • H-atom parameters constrained

  • w = 1/[σ2(Fo2) + (0.0384P)2 + 1.9833P] where P = (Fo2 + 2Fc2)/3

  • (Δ/σ)max < 0.001

  • Δρmax = 0.47 e Å−3

  • Δρmin = −0.36 e Å−3

Table 1
Selected geometric parameters (Å, °)

Mg1—Br1 2.4887 (9)
Mg1—O1 2.089 (2)
Mg1—N1 2.129 (3)
Mg1—C1i 2.149 (3)
Mg1—O2 2.374 (2)
O1—Mg1—N1 93.15 (9)
O1—Mg1—C1i 95.07 (10)
N1—Mg1—C1i 115.52 (11)
O1—Mg1—O2 175.18 (8)
N1—Mg1—O2 83.16 (8)
C1i—Mg1—O2 83.78 (8)
O1—Mg1—Br1 95.02 (6)
N1—Mg1—Br1 121.74 (8)
C1i—Mg1—Br1 120.98 (8)
O2—Mg1—Br1 89.57 (5)
C6—O2—C6i 108.2 (3)
C6—O2—Mg1i 115.36 (12)
C6i—O2—Mg1i 114.16 (12)
C6—O2—Mg1 114.16 (12)
C6i—O2—Mg1 115.36 (12)
Mg1i—O2—Mg1 88.86 (10)
Symmetry code: (i) [-y, -x, -z+{\script{1\over 2}}].

The possibility of partial positional disorder of C1 and N1 was checked; no evidence for such disorder was found. The disordered solvent (THF) mol­ecule was refined isotropically with restrained C—C and C—O distances. The position of the O atom in the five-membered ring of the solvent THF mol­ecule was assigned by analysis of isotropic displacement parameters and confirmed by the fact that the methyl­ene group could not be placed in the O22 site without forming unusually short inter­molecular H⋯H contacts (1.90–1.94 Å). All H atoms were placed in calculated positions (C—H = 0.95–0.99 Å) and refined using a riding model with Uiso(H) = 1.2Ueq(carrier)

Data collection: SMART (Bruker, 1998[Bruker (1998). SMART. Bruker AXS Inc., Madison, Wisconsin, USA,.]); cell refinement: SAINT (Bruker, 2003[Bruker (2003). SAINT. Bruker AXS Inc., Madison, Wisconsin, USA.]); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 1997[Sheldrick, G. M. (1997). SADABS, SHELXS97 and SHELXL97. University of Göttingen, Germany.]); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997[Sheldrick, G. M. (1997). SADABS, SHELXS97 and SHELXL97. University of Göttingen, Germany.]); molecular graphics: SHELXTL-Plus (Bruker, 2000[Bruker (2000). SHELXTL-Plus. Bruker AXS Inc., Madison, Wisconsin, USA.]); software used to prepare material for publication: SHELXTL-Plus.

Supporting information


Computing details top

Data collection: SMART (Bruker, 1998); cell refinement: SAINT (Bruker, 2003); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: SHELXTL-Plus (Bruker, 2000); software used to prepare material for publication: SHELXTL-Plus.

Di-µ-pyridyl-1:2κ2N:C2;2:1κ2N:C2-µ-tetrahydrofuran-κ2O:O- bis[bromo(tetrahydrofuran)magnesium(II)] tetrahydrofuran hemisolvate top
Crystal data top
[Mg2Br2(C5H4N)2(C4H8O)3]·0.5C4H8ODx = 1.445 Mg m3
Mr = 616.99Mo Kα radiation, λ = 0.71073 Å
Tetragonal, P4/nccCell parameters from 5951 reflections
Hall symbol: -P 4a 2acθ = 2.4–27.6°
a = 17.3368 (3) ŵ = 2.93 mm1
c = 18.8696 (4) ÅT = 120 K
V = 5671.53 (18) Å3Block, colourless
Z = 80.30 × 0.20 × 0.10 mm
F(000) = 2528
Data collection top
Bruker SMART 1K
diffractometer
3108 independent reflections
Radiation source: fine-focus sealed tube2022 reflections with I > 2σ(I)
Graphite monochromatorRint = 0.093
ω scansθmax = 27.0°, θmin = 1.7°
Absorption correction: multi-scan
(SADABS; Sheldrick, 1997)
h = 2215
Tmin = 0.473, Tmax = 0.758k = 2022
30363 measured reflectionsl = 1724
Refinement top
Refinement on F2Primary atom site location: structure-invariant direct methods
Least-squares matrix: fullSecondary atom site location: difference Fourier map
R[F2 > 2σ(F2)] = 0.039Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.085H-atom parameters constrained
S = 1.00 w = 1/[σ2(Fo2) + (0.0384P)2 + 1.9833P]
where P = (Fo2 + 2Fc2)/3
3108 reflections(Δ/σ)max < 0.001
161 parametersΔρmax = 0.47 e Å3
6 restraintsΔρmin = 0.36 e Å3
Special details top

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 (Å2) top
xyzUiso*/UeqOcc. (<1)
Br10.00140 (2)0.130532 (18)0.410058 (15)0.03633 (12)
Mg10.03748 (6)0.02350 (5)0.32866 (5)0.0227 (2)
N10.02342 (14)0.08313 (15)0.32806 (14)0.0306 (6)
C10.04365 (15)0.11090 (15)0.26120 (14)0.0185 (6)
C20.0382 (2)0.1275 (2)0.38650 (18)0.0391 (8)
H2A0.02310.10820.43150.047*
C30.0731 (2)0.1975 (2)0.3840 (2)0.0504 (10)
H3A0.08420.22520.42620.060*
C40.0918 (2)0.22714 (19)0.3187 (2)0.0512 (11)
H4A0.11480.27670.31480.061*
C50.07646 (18)0.18353 (19)0.2586 (2)0.0408 (9)
H5A0.08910.20460.21360.049*
O10.12524 (11)0.01943 (12)0.39346 (11)0.0297 (5)
C80.17086 (19)0.08419 (19)0.36970 (18)0.0354 (8)
H8A0.22090.06670.35020.043*
H8B0.14310.11390.33280.043*
C90.1827 (2)0.1326 (2)0.4360 (2)0.0499 (10)
H9A0.13860.16790.44390.060*
H9B0.23080.16330.43280.060*
C100.18817 (19)0.0729 (2)0.49443 (18)0.0469 (10)
H10A0.16940.09410.54000.056*
H10B0.24200.05510.50060.056*
C110.1372 (2)0.0084 (2)0.46924 (17)0.0461 (9)
H11A0.08730.00960.49460.055*
H11B0.16220.04200.47820.055*
O20.06215 (10)0.06215 (10)0.25000.0217 (6)
C60.14031 (16)0.05431 (17)0.27933 (16)0.0256 (7)
H6A0.13840.03180.32750.031*
H6B0.17220.02060.24880.031*
C70.17336 (18)0.13479 (18)0.28166 (16)0.0339 (8)
H7A0.15980.16120.32650.041*
H7B0.23020.13400.27630.041*
C210.7304 (14)0.751 (2)0.0028 (6)0.073 (7)*0.25
H21A0.68010.72430.00690.087*0.25
H21B0.74200.77700.04830.087*0.25
C240.7638 (17)0.7662 (10)0.1203 (6)0.064 (6)*0.25
H24A0.80900.79440.13920.076*0.25
H24B0.72510.76040.15850.076*0.25
C230.7875 (12)0.6884 (11)0.0919 (8)0.066 (5)*0.25
H23A0.83830.67320.11130.079*0.25
H23B0.74910.64870.10500.079*0.25
C250.7297 (18)0.8081 (12)0.0576 (10)0.111 (10)*0.25
H25A0.76090.85410.04570.133*0.25
H25B0.67630.82480.06810.133*0.25
O220.7917 (7)0.6964 (7)0.0158 (5)0.065 (3)*0.25
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
Br10.0532 (2)0.03296 (19)0.02287 (16)0.01342 (15)0.00432 (15)0.00763 (14)
Mg10.0277 (6)0.0229 (5)0.0176 (5)0.0017 (4)0.0006 (4)0.0012 (4)
N10.0280 (15)0.0321 (15)0.0317 (15)0.0020 (11)0.0009 (12)0.0085 (12)
C10.0185 (15)0.0150 (15)0.0220 (15)0.0005 (11)0.0058 (12)0.0039 (11)
C20.0325 (19)0.051 (2)0.0335 (18)0.0004 (17)0.0006 (15)0.0196 (17)
C30.038 (2)0.046 (3)0.067 (3)0.0085 (17)0.017 (2)0.030 (2)
C40.032 (2)0.0179 (18)0.103 (4)0.0012 (14)0.032 (2)0.012 (2)
C50.033 (2)0.036 (2)0.053 (2)0.0024 (15)0.0146 (17)0.0169 (17)
O10.0308 (12)0.0336 (13)0.0246 (11)0.0063 (9)0.0043 (9)0.0000 (9)
C80.0290 (19)0.037 (2)0.040 (2)0.0061 (15)0.0008 (15)0.0010 (16)
C90.037 (2)0.042 (2)0.070 (3)0.0078 (17)0.0093 (19)0.025 (2)
C100.033 (2)0.072 (3)0.036 (2)0.0074 (18)0.0024 (16)0.0212 (19)
C110.057 (2)0.055 (2)0.0258 (17)0.0040 (19)0.0140 (16)0.0038 (17)
O20.0206 (9)0.0206 (9)0.0238 (15)0.0000 (11)0.0027 (8)0.0027 (8)
C60.0174 (16)0.0322 (18)0.0273 (16)0.0017 (13)0.0028 (12)0.0018 (13)
C70.0302 (19)0.038 (2)0.0336 (19)0.0065 (15)0.0006 (14)0.0055 (14)
Geometric parameters (Å, º) top
Mg1—Br12.4887 (9)C10—H10A0.9900
Mg1—O12.089 (2)C10—H10B0.9900
Mg1—N12.129 (3)C11—H11A0.9900
Mg1—C1i2.149 (3)C11—H11B0.9900
Mg1—O22.374 (2)O2—C61.470 (3)
Mg1—Mg1i3.3237 (18)O2—C6i1.470 (3)
N1—C21.369 (4)O2—Mg1i2.374 (2)
N1—C11.395 (3)C6—C71.509 (4)
C1—C51.383 (4)C6—H6A0.9900
C1—Mg1i2.149 (3)C6—H6B0.9900
C2—C31.356 (5)C7—C7i1.524 (6)
C2—H2A0.9500C7—H7A0.9900
C3—C41.373 (5)C7—H7B0.9900
C3—H3A0.9500C21—O221.46 (2)
C4—C51.390 (5)C21—C251.511 (19)
C4—H4A0.9500C21—H21A0.9900
C5—H5A0.9500C21—H21B0.9900
O1—C81.445 (3)C24—C231.507 (16)
O1—C111.458 (4)C24—C251.508 (15)
C8—C91.521 (5)C24—H24A0.9900
C8—H8A0.9900C24—H24B0.9900
C8—H8B0.9900C23—O221.444 (16)
C9—C101.515 (5)C23—H23A0.9900
C9—H9A0.9900C23—H23B0.9900
C9—H9B0.9900C25—H25A0.9900
C10—C111.502 (4)C25—H25B0.9900
O1—Mg1—N193.15 (9)C9—C10—H10B111.0
O1—Mg1—C1i95.07 (10)H10A—C10—H10B109.0
N1—Mg1—C1i115.52 (11)O1—C11—C10107.3 (3)
O1—Mg1—O2175.18 (8)O1—C11—H11A110.3
N1—Mg1—O283.16 (8)C10—C11—H11A110.3
C1i—Mg1—O283.78 (8)O1—C11—H11B110.3
O1—Mg1—Br195.02 (6)C10—C11—H11B110.3
N1—Mg1—Br1121.74 (8)H11A—C11—H11B108.5
C1i—Mg1—Br1120.98 (8)C6—O2—C6i108.2 (3)
O2—Mg1—Br189.57 (5)C6—O2—Mg1i115.36 (12)
O1—Mg1—Mg1i129.87 (6)C6i—O2—Mg1i114.16 (12)
N1—Mg1—Mg1i63.98 (7)C6—O2—Mg1114.16 (12)
C1i—Mg1—Mg1i62.31 (8)C6i—O2—Mg1115.36 (12)
O2—Mg1—Mg1i45.57 (5)Mg1i—O2—Mg188.86 (10)
Br1—Mg1—Mg1i135.11 (2)O2—C6—C7106.0 (2)
C2—N1—C1119.2 (3)O2—C6—H6A110.5
C2—N1—Mg1125.2 (2)C7—C6—H6A110.5
C1—N1—Mg1115.41 (18)O2—C6—H6B110.5
C5—C1—N1116.8 (3)C7—C6—H6B110.5
C5—C1—Mg1i125.3 (2)H6A—C6—H6B108.7
N1—C1—Mg1i117.92 (18)C6—C7—C7i102.49 (18)
C3—C2—N1123.9 (4)C6—C7—H7A111.3
C3—C2—H2A118.0C7i—C7—H7A111.3
N1—C2—H2A118.0C6—C7—H7B111.3
C2—C3—C4118.1 (3)C7i—C7—H7B111.3
C2—C3—H3A120.9H7A—C7—H7B109.2
C4—C3—H3A120.9O22—C21—C25104.4 (13)
C3—C4—C5118.9 (3)O22—C21—H21A110.9
C3—C4—H4A120.5C25—C21—H21A110.9
C5—C4—H4A120.5O22—C21—H21B110.9
C1—C5—C4123.0 (3)C25—C21—H21B110.9
C1—C5—H5A118.5H21A—C21—H21B108.9
C4—C5—H5A118.5C23—C24—C25105.0 (9)
C8—O1—C11109.2 (2)C23—C24—H24A110.7
C8—O1—Mg1119.60 (18)C25—C24—H24A110.7
C11—O1—Mg1129.16 (18)C23—C24—H24B110.7
O1—C8—C9104.3 (3)C25—C24—H24B110.7
O1—C8—H8A110.9H24A—C24—H24B108.8
C9—C8—H8A110.9O22—C23—C24106.3 (11)
O1—C8—H8B110.9O22—C23—H23A110.5
C9—C8—H8B110.9C24—C23—H23A110.5
H8A—C8—H8B108.9O22—C23—H23B110.5
C10—C9—C8103.3 (3)C24—C23—H23B110.5
C10—C9—H9A111.1H23A—C23—H23B108.7
C8—C9—H9A111.1C24—C25—C21105.8 (11)
C10—C9—H9B111.1C24—C25—H25A110.6
C8—C9—H9B111.1C21—C25—H25A110.6
H9A—C9—H9B109.1C24—C25—H25B110.6
C11—C10—C9104.0 (3)C21—C25—H25B110.6
C11—C10—H10A111.0H25A—C25—H25B108.7
C9—C10—H10A111.0C23—O22—C21105.3 (12)
C11—C10—H10B111.0
Symmetry code: (i) y, x, z+1/2.
 

Acknowledgements

The authors thank the RFBR for financial support (grant 04-03-32288). AVC is grateful to the Russian Science Support Foundation.

References

First citationAl-Juaid, S. S., Avent, A. G., Eaborn, C., El-Hamruni, S. M., Hawkes, S. A., Hill, M. S., Hopman, M., Hitchcock, P. B. & Smith, J. D. (2001). J. Organomet. Chem. 631, 76–86.  Web of Science CSD CrossRef CAS Google Scholar
First citationAllen, F. H. (2002). Acta Cryst. B58, 380–388.  Web of Science CSD CrossRef CAS IUCr Journals Google Scholar
First citationBruker (1998). SMART. Bruker AXS Inc., Madison, Wisconsin, USA,.  Google Scholar
First citationBruker (2000). SHELXTL-Plus. Bruker AXS Inc., Madison, Wisconsin, USA.  Google Scholar
First citationBruker (2003). SAINT. Bruker AXS Inc., Madison, Wisconsin, USA.  Google Scholar
First citationCotton, F. A., Haefner, S. C., Matonic, J. H., Wang, X. & Murillo, C. A. (1997). Polyhedron, 16, 541–550.  CSD CrossRef CAS Web of Science Google Scholar
First citationFurukava, N., Shibutani, T. & Fujihara, H. (1987). Tetrahedron Lett. 28, 5845–5848.  CrossRef Web of Science Google Scholar
First citationParadies, H. H. (1974). Naturwissenschaften, 61, 168–169.  CSD CrossRef CAS Google Scholar
First citationParadies, H. H. & Görbing, M. (1969). Angew. Chem. 81, 293.  CrossRef Google Scholar
First citationSheldrick, G. M. (1997). SADABS, SHELXS97 and SHELXL97. University of Göttingen, Germany.  Google Scholar
First citationToney, J. & Stucky, G. D. (1971). J. Organomet. Chem. 28, 5–20.  CSD CrossRef Google Scholar
First citationTrécourt, F., Breton, G., Bonnet, V., Mongin, F., Marsais, F. & Queguiner, G. (1999). Tetrahedron Lett. 40, 4339–4342.  Web of Science CrossRef CAS Google Scholar
First citationVallino, M. (1969). J. Organomet. Chem. 20, 1–10.  CSD CrossRef CAS Web of Science Google Scholar

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