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Volume 61 
Part 8 
Pages m1588-m1589  
August 2005  

Received 26 April 2005
Accepted 24 June 2005
Online 16 July 2005

Key indicators
Single-crystal X-ray study
T = 153 K
Mean [sigma](C-C) = 0.006 Å
R = 0.047
wR = 0.109
Data-to-parameter ratio = 15.1
Details

(Acetonitrile-[kappa]N){1,2-bis[bis(pentafluorophenyl)phosphino]ethane-[kappa]2P,P}([eta]5-pentamethylcyclopentadienyl)ruthenium(II) hexafluorophosphate

aSchool of Chemistry, Queen's University Belfast, David Keir Building, Belfast BT9 5AG, Northern Ireland
Correspondence e-mail: g.saunders@qub.ac.uk

The cation of the title salt, [Ru([eta]5-C5Me5)(NCMe){(C6F5)2PCH2CH2P(C6F5)2}]PF6 or [Ru(C10H15)(C26H4F20P2)(C2H3N)]PF6, has contacts with three anions. One lies close to the pentamethylcyclopentadienyl ring, such that three F atoms of the anion are ca 3.5 Å from two of the ring methyl C atoms of the cation and there is one H...F distance shorter than the sum of the van der Waals radii.

Comment

Salts of the cation [([eta]5-C5Me5)RhCl{(C6F5)2PCH2CH2P(C6F5)2}]+ have been found to undergo intramolecular dehydrofluorinative C-C reactions on thermolysis or in the presence of a proton sponge or fluoride, to yield [{[eta]5,[kappa]P,[kappa]P-C5Me4CH2C6F4-2-P(C6F5)CH2CH2P(C6F5)2}RhCl]+ and then [{[eta]5,[kappa]P,[kappa]P-C5Me3[CH2C6F4-2-P(C6F5)CH2]-1,3}RhCl]+ (Atherton et al., 1996[Atherton, M. J., Fawcett, J., Holloway, J. H., Hope, E. G., Karaçar, A., Russell, D. R. & Saunders, G. C. (1996). J. Chem. Soc. Dalton Trans. pp. 3215-3220.]; Bellabarba et al., 2001[Bellabarba, R. M., Nieuwenhuyzen, M. & Saunders, G. C. (2001). J. Chem. Soc. Dalton Trans. pp. 512-514.]). The thermolysis is dependent on the solvent and the anion. The reaction for the tetrafluoroborate salt occurs only in polar protic solvents, such as ethanol, whereas for chloride, hexafluorophosphate and tetraphenylborate salts, the reaction also occurs readily in non-polar aprotic solvents, such as benzene (Atherton et al., 1999[Atherton, M. J. Fawcett, J., Holloway, J. H., Hope, E. G., Russell, D. R. & Saunders G. C. (1999). J. Organomet. Chem. 582, 163-172.]).

The structure of [([eta]5-C5Me5)RhCl{(C6F5)2PCH2CH2P(C6F5)2}]BF4 revealed that a tetrafluoroborate anion is positioned close to the pentamethylcyclopentadienyl ligand, such that three F atoms of the anion form a plane almost parallel (5.1° deviation) to the C5 plane, with a separation between the two planes of ca 3.19 Å. The anion is displaced slightly from the ([eta]5-C5Me5)-Rh axis, giving rise to short F...H and F...C distances between the anion and the pentamethylcyclopentadienyl ligand of 2.4-2.7 and 3.1-3.3 Å, respectively (Atherton et al., 1996[Atherton, M. J., Fawcett, J., Holloway, J. H., Hope, E. G., Karaçar, A., Russell, D. R. & Saunders, G. C. (1996). J. Chem. Soc. Dalton Trans. pp. 3215-3220.]). A similar positioning of the anion and cation is found in the related salts [([eta]5-C5Me5)IrCl{(C6F5)2PCH2CH2P(C6F5)2}]BF4 (Atherton et al., 1996[Atherton, M. J., Fawcett, J., Holloway, J. H., Hope, E. G., Karaçar, A., Russell, D. R. & Saunders, G. C. (1996). J. Chem. Soc. Dalton Trans. pp. 3215-3220.]) and [([eta]5-C5Me5)RhCl{(C6H3F2-2,6)2PCH2CH2P(C6H3F2-2,6)2}]BF4 (Fawcett et al., 1998[Fawcett, J., Friedrichs, S., Holloway, J. H., Hope, E. G., McKee, V., Nieuwenhuyzen, M., Russell, D. R. & Saunders, G. C. (1998). J. Chem. Soc. Dalton Trans. pp. 1477-1484.]). If BF4-...C5Me5 interactions are present in aprotic solvents, then the absence of similar anion...C5Me5 interactions in the salts of the other anions may provide the basis for an explanation for the difference in reactivity. Of particular relevance is the salt of the hexafluorophosphate anion, which is the most similar to the tetrafluoroborate anion. These two anions comprise a periphery of F atoms, with equilateral triangular faces with edges of ca 2.1-2.3 Å (Allen et al., 1987[Allen, F. H., Kennard, O., Watson, D. G., Brammer, L., Orpen, A. G. & Taylor, R. (1987). J. Chem. Soc. Perkin Trans. 2, pp. S1-19.]; Atherton et al., 1996[Atherton, M. J., Fawcett, J., Holloway, J. H., Hope, E. G., Karaçar, A., Russell, D. R. & Saunders, G. C. (1996). J. Chem. Soc. Dalton Trans. pp. 3215-3220.]; Fawcett et al., 1998[Fawcett, J., Friedrichs, S., Holloway, J. H., Hope, E. G., McKee, V., Nieuwenhuyzen, M., Russell, D. R. & Saunders, G. C. (1998). J. Chem. Soc. Dalton Trans. pp. 1477-1484.]). Unfortunately, crystals suitable for single-crystal X-ray diffraction studies of the non-tetrafluoroborate salts of [([eta]5-C5Me5)RhCl{(C6F5)2PCH2CH2P(C6F5)2}]+ have been elusive. However, the structure of the title isoelectronic ruthenium salt, [([eta]5-C5Me5)Ru(NCMe){(C6F5)2PCH2CH2P(C6F5)2}]PF6, (I)[link], has now been determined and is presented here.

[Scheme 1]

The structure of (I)[link] (Fig. 1[link]) reveals that the hexafluorophosphate anion does not adopt a similar position to that of the tetrafluoroborate anion in [([eta]5-C5Me5)RhCl{(C6F5)2PCH2CH2P(C6F5)2}]BF4 and [([eta]5-C5Me5)RhCl{(C6H3F2-2,6)2PCH2CH2P(C6H3F2-2,6)2}]BF4. The cation shows contacts to three anions which are shorter than the sum of the van der Waals radii of the respective atoms. One anion position is close to the pentamethylcyclopentadienyl ligand, such that there is one F...H distance shorter than the sum of the van der Waals radii (F36...H10C = 2.626 Å). The shortest inter-ion F...C(C5Me5) distances are between atoms F34 and C9 [3.493 (6) Å], F36 and C10 [3.564 (7) Å], and F32 and C10 [3.597 (7) Å]. However, for this anion, the shortest inter-ion F...C distance of 3.028 (6) Å is between atoms F36 and C2S of the acetonitrile. The distance between atoms C3S and F36 is 3.123 (5) Å, with F36...H3S2 = 2.609 Å, and that between atoms C3S and F34 is 3.396 (7) Å, with F34...H3S2 = 2.481 Å.

Another anion position gives three short contacts with a C6F5 ring (F32...F26B = 2.888 (6) Å, F32...C26B = 2.964 (6) Å and F32...C25B = 3.110 (6) Å) and a contact with a CH2 H atom (F35...H2A2 = 2.633 Å). The third anion position gives a contact with a C6F5 ring (F31...C14B = 3.113 (7) Å), a CH2 H atom (F33...H1A1 = 2.599 Å) and an acetonitrile H atom (F35...H3S1 = 2.428 Å).

[Figure 1]
Figure 1
A view of (I)[link]. Displacement ellipsoids are drawn at the 30% probability level. H atoms have been omitted for clarity.

Experimental

The title complex was obtained from the reaction of [([eta]5-C5Me5)Ru(NCMe)3]PF6 with (C6F5)2PCH2CH2P(C6F5)2 in dichloromethane (10 ml) gave a yellow-green solution from which a small number of yellow crystals of (I)[link] were obtained by cooling the reaction mixture to 273 K.

Crystal data
  • [Ru(C10H15)(C26H4F20P2)(C2H3N)]PF6

  • Mr = 1180.55

  • Monoclinic, P 21 /n

  • a = 12.5380 (9) Å

  • b = 10.6157 (8) Å

  • c = 31.760 (2) Å

  • [beta] = 98.062 (2)°

  • V = 4185.4 (5) Å3

  • Z = 4

  • Dx = 1.874 Mg m-3

  • Mo K[alpha] radiation

  • Cell parameters from 5351 reflections

  • [theta] = 4-50°

  • [mu] = 0.64 mm-1

  • T = 153 (2) K

  • Needle, red

  • 0.42 × 0.10 × 0.08 mm

Data collection
  • Bruker SMART 1000 CCD area-detector diffractometer

  • [varphi] and [omega] scans

  • Absorption correction: multi-scan(SADABS; Sheldrick, 1996[Sheldrick, G. M. (1996). SADABS. University of Göttingen, Germany.])Tmin = 0.775, Tmax = 0.951

  • 37499 measured reflections

  • 9479 independent reflections

  • 5575 reflections with I > 2[sigma](I)

  • Rint = 0.098

  • [theta]max = 27.5°

  • h = -16 [rightwards arrow] 16

  • k = -13 [rightwards arrow] 13

  • l = -41 [rightwards arrow] 40

Refinement
  • Refinement on F2

  • R[F2 > 2[sigma](F2)] = 0.047

  • wR(F2) = 0.109

  • S = 0.94

  • 9479 reflections

  • 627 parameters

  • H-atom parameters constrained

  • w = 1/[[sigma]2(Fo2) + (0.0422P)2] where P = (Fo2 + 2Fc2)/3

  • ([Delta]/[sigma])max < 0.001

  • [Delta][rho]max = 0.67 e Å-3

  • [Delta][rho]min = -0.83 e Å-3

H atoms were added in idealized positions and a riding model with fixed displacement parameters [Uiso(H) = 1.2Ueq of the parent atom (1.5Ueq for methyl H atoms].

Data collection: SMART (Bruker, 2001[Bruker (2001). SMART (Version 5.622) and SHELXTL (Version 6.12). Bruker AXS Inc., Madison, Wisconsin, USA.]); cell refinement: SAINT (Bruker, 2002[Bruker (2002). SAINT. Version 6.36a. Bruker AXS Inc., Madison, Wisconsin, USA.]); data reduction: SHELXTL (Bruker, 2001[Bruker (2001). SMART (Version 5.622) and SHELXTL (Version 6.12). Bruker AXS Inc., Madison, Wisconsin, USA.]) and SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 1997[Sheldrick, G. M. (1997). SHELXS97 and SHELXL97. University of Göttingen, Germany.]); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997[Sheldrick, G. M. (1997). SHELXS97 and SHELXL97. University of Göttingen, Germany.]); molecular graphics: SHELXTL; software used to prepare material for publication: SHELXTL.

Acknowledgements

We thank the EPSRC for support.

References

Allen, F. H., Kennard, O., Watson, D. G., Brammer, L., Orpen, A. G. & Taylor, R. (1987). J. Chem. Soc. Perkin Trans. 2, pp. S1-19.
Atherton, M. J., Fawcett, J., Holloway, J. H., Hope, E. G., Karaçar, A., Russell, D. R. & Saunders, G. C. (1996). J. Chem. Soc. Dalton Trans. pp. 3215-3220.
Atherton, M. J. Fawcett, J., Holloway, J. H., Hope, E. G., Russell, D. R. & Saunders G. C. (1999). J. Organomet. Chem. 582, 163-172.
Bellabarba, R. M., Nieuwenhuyzen, M. & Saunders, G. C. (2001). J. Chem. Soc. Dalton Trans. pp. 512-514.
Bruker (2001). SMART (Version 5.622) and SHELXTL (Version 6.12). Bruker AXS Inc., Madison, Wisconsin, USA.
Bruker (2002). SAINT. Version 6.36a. Bruker AXS Inc., Madison, Wisconsin, USA.
Fawcett, J., Friedrichs, S., Holloway, J. H., Hope, E. G., McKee, V., Nieuwenhuyzen, M., Russell, D. R. & Saunders, G. C. (1998). J. Chem. Soc. Dalton Trans. pp. 1477-1484.
Sheldrick, G. M. (1996). SADABS. University of Göttingen, Germany.
Sheldrick, G. M. (1997). SHELXS97 and SHELXL97. University of Göttingen, Germany.


Acta Cryst (2005). E61, m1588-m1589   [ doi:10.1107/S1600536805020052 ]