Synthesis of dinuclear and trinuclear ruthenium cyclopropenyl complexes

(1)

Synthesis of Dinuclear and Trinuclear Ruthenium

Cyclopropenyl Complexes

Chiung-Cheng Huang, Ying-Chih Lin,* Shou-Ling Huang, Yi-Hong Liu, and

Yu Wang

Department of Chemistry, National Taiwan University, Taipei, Taiwan, 106 Republic of China

Received November 4, 2002

Dinuclear ruthenium cyclopropenyl complexes

{

[Ru]CdC(CHR)

}

2C6H4

([Ru] ) (η

5

-C5H5)(PPh3)2Ru, R ) CN, 3a; R ) CH2

dCH

2, 3b; R ) Ph, 3c) are prepared by deprotonation

of corresponding vinylidene complexes

{

[Ru]dCdC(CH

2R)

}

2C6H42+

_{(2). For the vinylidene}

complex 2d (R ) CO2Me) with an ester group, the deprotonation reaction leads to formation

of the dinuclear bis-furyl complex

{

[Ru]CdC(CHdC(O)OMe)

}

2C6H4

(5d). Electrophilic

addition of TCNQ to both three-membered rings of 3a yields the zwitterionic bis-vinylidene

complex

{

[Ru]dCdC[CH(TCNQ)CN]

}

2C6H4

(4a), which, in the presence of

MeOH/n-Bu4-NOH, gives the methoxy-substituted bis-cyclopropenyl complex

{

[Ru]CdC(C(OMe)CN)

}

2C6H4

(6a). The proton-induced demethoxylation of 6a generates

{

[Ru]CC(C(CN))

}

2C6H42+

_(7a).

The reaction of TMSN3

with 3a gives the bis-tetrazolate complex

{

[Ru](N4C)CH(CH2-CN)

}

2C6H4

(8a). Trinuclear tris-cyclopropenyl complexes

{

[Ru]CdC(CHR)C6H4CtC

}

3C6H3

(R ) CN, 11a; R ) CH2

dCH

2, 11b; R ) Ph, 11c) are obtained from deprotonation of

{

1,3,5-{

[Ru]dCdC(CH2R)C6H4CtC

}

3C6H3

}

3+

_{(10). Complex 2b is characterized by X-ray diffraction}

analysis, and other complexes are characterized by spectroscopic methods.

Introduction

Cyclopropene is believed to be the most highly strained

cycloalkene, with an estimated strain energy of more

than 50 kcal/mol.

1

_{This molecule has hence been under}

intense investigation

2

_{and has played a crucial role in}

the development of the concept of aromaticity.

3

Chemi-cal reactivity of this molecule has also been addressed.

4-7

However, transition metal cyclopropenyl complexes are

rare,

8

_{even though participation of d orbitals in these}

complexes is expected to significantly stabilize the

molecule. Previously we reported the facile synthesis of

several mononuclear ruthenium cyclopropenyl

com-plexes

9

_{by deprotonation of (η}

5

_{-C5H5)(PPh3)2RudCd}

C(Ph)CH

2

R

+

in which CR

of the vinylidene ligand is

known to be electron deficient. Thus deprotonation at

C

γ

causes intramolecular nucleophilic addition at CR,

leading to the formation of cyclopropenyl complexes. As

applications of dendrimers are currently being

investi-gated for use as biomimetic catalysts,

10

_{building blocks}

for fabrication of designed materials,

11

_molecular

car-riers for chemical catalysts,

12

_{and potential vehicles for}

delivery of drugs and immunogens,

13

_{we extend our}

synthesis to a few small preliminary dendrimeric

sys-tems. Herein we report the preparation of dinuclear and

trinuculear ruthenium vinylidene and cyclopropenyl

complexes using 1,4-diethynylbenzene and 1,3,5-(HCt

CC6H4CtC)3C6H3

14

_{as core backbones, respectively.}

(1) (a) Special issue on strained organic compounds: Chem. Rev.

1989, 89. (b) Liebman, J. F.; Greenberg, A. Strained Organic Molecules; Wiley: New York, 1978; p 91.

(2) (a) Marier, G.; Periss, T.; Reisenauer, H. P.; Hess, B. A., Jr.; Schand, L. J. J. Am. Chem. Soc. 1994, 116, 2014. (b) Hopf, H.; Plagens, A.; Walsh, R. J. Chem. Soc., Chem. Commun. 1994, 1467.

(3) (a) Liebman, J. F.; Greenberg, A. Chem. Rev. 1976, 76, 311. (b) Halton, B.; Banwell, M. G. In The Chemistry of the Cyclopropnyl Group; Patai, S., Rappoport, Z., Eds.; Wiley: Chichester, 1987; Part 2, Chapter 21, p 1223.

(4) (a) Lahti, P. M.; Berson, J. A. J. Am. Chem. Soc. 1981, 103, 7011. (b) Rigby, J. H.; Kierkus, P. C. J. Am. Chem. Soc. 1989, 111, 4125. (c) Deem, M. L. Synthesis 1972, 675. (d) Galloway, N.; Deut, B. R.; Halton, B. Aust. J. Chem. 1983, 36, 593. (e) Gompper, R.; Choenafinder, K. Chem. Ber. 1979, 112, 1529. (f) Mueller, P.; Bernardinelli, G.; Pfyffer, J.; Schaller, J. P. Helv. Chim. Acta 1991, 74, 993.

(5) Bailey, I. M.; Walsh, R. J. Chem. Soc., Faraday Trans. 1 1978, 74, 1146.

(6) (a) Padwa, A.; Blacklock, T. J.; Getman, D.; Hatanaka, N.; Loza, R. J. Org. Chem. 1978, 43, 1481. (b) Padwa, A. Acc. Chem. Res. 1979, 12, 310. (c) Arnold, D. R.; Humphreys, R. W.; Leigh, W. J.; Palmer, G. E. J. Am. Chem. Soc. 1976, 98, 6625. (d) Zimmerman, H. E.; Aasen, S. M. J. Am. Chem. Soc. 1977, 99, 2342.

(7) (a) Franck-Neumann, M.; Miesch, M.; Kempf, H. Tetrahedron 1988, 44, 2933. (b) Dombrovskii, V. S.; Yakushikina N. I.; Bolesov, I. G. Zh. Org. Khim. 1979, 15, 1184.

(8) Gompper, R.; Bartmann, E. Angew. Chem., Int. Ed. Engl. 1985, 24, 3.

(9) (a) Ting, P. C.; Lin, Y. C.; Cheng, M. C.; Wang, Y. Organome-tallics 1994, 13, 2150. (b) Ting, P. C.; Lin, Y. C.; Lee, G. H.; Cheng, M. C.; Wang, Y. J. Am. Chem. Soc. 1996, 112, 6433. (c) Lo, Y. H.; Lin, Y. C.; Lee, G. H.; Wang, Y. Organometallics 1999, 18, 982. (d) Chang, C. W.; Lin, Y. C.; Lee, G. H.; Wang, Y. Organometallics 2000, 19, 3211. (10) Huck, W. T. S.; Prins, L. J.; Fokkens, R. H.; Nibbering, N. M. M.; van Veggel, F. C. J. M.; Reinhoudt, D. N. J. Am. Chem. Soc. 1998, 120, 6240.

(11) Mongin, O.; Gossauer, A. Tetrahedron Lett. 1996, 37, 3825. (12) Knapen, J. W. J.; van der Made, A. W.; de Wilde, J. C.; van Leeuwen, P. W. W. N. M.; Wijkens, P.; Grove, D. M.; van Koten, G. Nature 1994, 372, 659.

(13) (a) Duncan, R.; Kopecek, J. Adv. Polym. Sci. 1984, 57, 51. (b) Peppas, N. A.; Nagai, T.; Miyajima, M. Pharm. Technol. Jpn. 1994, 10, 611. (c) Bieniarz, C. Dendrimers: Applications to Pharmaceutical and Medicinal Chemistry. In Encyclopedia of Pharmaceutical Technol-ogy; Marcel Dekker: New York, 1999; p 55.

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(2)

Other dinuclear ruthenium complexes obtained from the

bis-vinylidene complex are also reported.

Results and Discussion

Preparation of Dinuclear Vinylidene Complexes.

Treatment of [Ru]Cl with 1,4-diethynylbenzene in the

presence of NaPF6

afforded a deep red solution

contain-ing a vinylidene intermediate, which underwent

depro-tonation in the presence of sodium methoxide to give

the dinuclear bis-acetylide complex 1 in 84% yield.

15,16

With half an equivalent of bisalkyne the reaction yields

no mononuclear complex. The singlet resonance at δ

50.98 in the

31

_{P NMR spectrum of 1 is in the region of}

a regular ruthenium acetylide complex.

17

_{The mass}

spectrum of 1 gives the parent peaks at m/z ) 1506 as

well as fragmentations due to loss of phosphines. Bruce

and co-workers carried out the reaction of

1,4-bis-(trimethylsilylethynyl)benzene with 1 equiv of [Ru]Cl

in the presence of KF to give first [Ru](CtCC6H4Ct

CSiMe3). Then addition of another equivalent of

[Ru]-Cl and KF cleaved the remaining C-Si bond with

concomitant formation of the other Ru-C bond to afford

the same acetylide complex 1. Direct use of 2 equiv of

[Ru]Cl and KF also afforded 1.

18

Reactions of 1 with various alkyl halides RCH

2

X

generate dinuclear bis-vinylidene complexes

{

[Ru]dCd

C(CH

2

R)

}

2

C

6

H

42+

(2) in high yield (Scheme 1). For

example, the reaction of 1 with ICH2CN at 40 °C yields

the dicationic bis-vinylidene complex

{

[Ru]dCdC(CH2-CN)

}

2C6H42+

_{(2a). Several analogous vinylidene}

com-plexes 2 (R ) CH2

_dCH

2, 2b; R ) Ph, 2c; R ) CO2CH3,

2d; R ) CO

2Et, 2e) are similarly prepared. All these

vinylidene complexes, 2a-e, display a characteristic

deep red color and deshielded

13

_{C resonances at δ 345}

( 5 assignable to CR

of the vinylidene ligand.

19 31

_{P NMR}

resonances of 2 appear at around δ 42 ( 1 in CDCl3

as

singlets due to the fluxional behavior of the vinylidene

ligand at room temperature.

20

_{Complexes 1 and 2 are}

less soluble than their corresponding mononuclear

complexes. Previously we reported

9b

_{the transformation}

of a mononuclear ruthenium cyclopropenyl complex to

the dimeric dication vinylidene complex

{

[Ru]dCd

C(Ph)CH(CN)-

}

22+

, which, upon deprotonation, yielded

the bis-cyclopropenyl complex

{

[Ru]CdC(Ph)C(CN)-

}

2.

The two cyclopropenyl groups are bound together

di-rectly by the sp

3

_{carbon of the three-membered ring. The}

formation of this complex probably involves the cationic

ruthenium vinylidene radical

21

_{formed from the reaction}

of the mononuclear ruthenium cyclopropenyl complex

with allyl iodide.

Single crystals of 2b suitable for X-ray diffraction

analysis are obtained by recrystallization from CDCl3.

Complex 2b crystallized with only one independent

molecule in the unit cell and cocrystallized with

coun-terion and chloroform molecules. The solid-state

struc-ture of 2b is shown in Figure 1, and representative bond

lengths and bond angles are reported in Table 1. The

molecule possesses an inversion center at the center of

the core phenyl group. The RudC bond length of

1.853-(4) Å is in the range of a regular RudC bond of other

crystallographically characterized ruthenium vinylidene

complexes.

16b

_{The disorder of an allyl group usually}

observed for metal complexes containing such a ligand

is not observed in 2b, possibly due to bulky phosphine

ligands that restrict the number of accessible

conforma-(14) (a) Uno, M.; Dixneuf, P. H. Angew. Chem., Int. Ed. 1998, 37,

1714. (b) McDonagh, A. M.; Humphrey, M. G.; Samoc, M.; Davies, B. L.; Hiubrechts, S.; Wada, T.; Sasabe, H.; Persoon, A. J. Am. Chem. Soc. 1999, 121, 1405.

(15) Bruce, M. I.; Wallis, R. C. Aust. J. Chem. 1979, 32, 1471. (16) For general reviews, see: (a) Bruce, M. I.; Swincer, A. G. Adv. Organomet. Chem. 1987, 52, 3940. (b) Bruce, M. I. Chem. Rev. 1991, 91, 197.

(17) (a) Whittall, I. R.; Humphrey, M. G.; Persoons, A.; Houbrechts, S. Organometallics 1996, 15, 1935. (b) Wu, I. Y.; Lin, J. T.; Luo, J.; Li, C. S.; Tsai, C.; Wen, Y. S.; Hsu, C. C.; Yeh, F. F.; Liou, S. Organome-tallics 1998, 17, 2188.

(18) (a) Bruce, M. I.; Hall, B. C.; Kelly, B. D.; Low, P. J.; Skelton B. W.; White, A. H. J. Chem. Soc., Dalton Trans. 1999, 3719. (b) Bruce, M. I.; Hall, B. C.; Low, P. J.; Skelton B. W.; White, A. H. J. Organomet. Chem. 1999, 592, 74.

(19) Werner, H.; Bachmann, P.; Martin, M. Can. J. Chem. 2001, 79, 519.

(20) (a) Allen, D. L.; Gibson, V. C.; Green, M. L.; Skinner, T. F.; Bashikin, J.; Grebenik, P. D. J. Chem. Soc., Chem. Commun. 1985, 895. (b) Consiglio, G.; Morandini, F. Chem. Rev. 1987, 87, 761.

(21) (a) Rabier, A.; Lugan, N.; Mathieu, R.; Geoffroy, G. L. Orga-nometallics 1994, 13, 4676. (b) Antinolo, A.; Otero, A.; Fajardo, M.; Garcia-Yebra, C.; Gil-Sanz, R.; Lopez-Mardomingo, C.; Martin, A.; Gomez-Sal, P. Organometallics 1994, 13, 4679.

Scheme 1

Figure 1. ORTEP drawing of complex 2b (30% probability

ellipsoids).

Table 1. Selected Bond Distances (Å) and Angles (deg) of 1,4-{[Ru]CdC(CH2CHdCH2)}2C6H42+(2b) Ru(1)-C(1) 1.853(4) Ru(1)-C(9) 2.235(4) Ru(1)-C(10) 2.240(4) Ru(1)-C(13) 2.243(4) Ru(1)-C(11) 2.285(4) Ru(1)-C(12) 2.295(4) Ru(1)-P(1) 2.3429(11) Ru(1)-P(2) 2.3708(11) C(1)-C(2) 1.311(6) C(2)-C(7) 1.497(6) C(2)-C(3) 1.525(7) C(3)-C(4) 1.465(10) C(4)-C(5) 1.237(12) C(2)-C(1)-Ru(1) 174.0(3) C(1)-C(2)-C(7) 119.7(4) C(1)-C(2)-C(3) 120.8(4) C(7)-C(2)-C(3) 119.3(4) C(4)-C(3)-C(2) 116.2(6) C(5)-C(4)-C(3) 127.5(4)

(3)

tions. The torsion angle C(3)-C(2)-C(7)-C(6) is

54.9-(5)° and C(1)-C(2)-C(7)-C(8) is 60.754.9-(5)°, indicating

that the core phenyl group is not coplanar with the

vinylidene plane.

Dinuclear Cyclopropenyl and Furyl Complexes.

Deprotonation of the vinylidene complex 2a by

n-Bu4-NOH in acetone is accompanied with a cyclization

reaction affording the bis-cyclopropenyl complex

{

[Ru]-CdC(CHCN)

}

2C6H4

(3a). To prevent attack of halide

anion to the metal, NH4PF6

was added. With two

stereogenic carbon centers in 3a, it is not surprising to

see two sets of coupled doublets at δ 51.9, 49.3 (JP-P

)

36.4 Hz) and 51.8, 49.2 (JP-P

) 35.2 Hz) in the

31

_{P NMR}

spectrum of 3a. The intensity ratio of 1:1 attributed to

stereoisomers indicates no diastereoselectivity. For the

1

_{H NMR spectrum of 3a, only in C6D6,}

1

_{H resonances}

of two diastereomers are distinguishable. Complex 3a

is more stable than the neutral 2,2

′

-bicyclopropenyl

complex

{

[Ru]CdC(Ph)CCN

}

2

previously reported by

us.

9b

_{Using the same method two other dinuclear}

cyclopropenyl complexes

{

[Ru]CdC(CHCHdCH2)

}

2C6H4

(3b) and

{

[Ru]CdC(CHPh)

}

2

C

6

H

4

(3c) are prepared.

Characteristic spectroscopic data of 3b and 3c are

similar to those of 3a. The

31

_{P NMR data of 3b and}

3c reveal the presence of diastereomers both in 1:1

ra-tio. Protonation of 3 readily regenerates 2.

Prepara-tion of the organic phenyl bridged biscyclopropene

1,4-[PhCdC(C(Ph)(t-BuO))]C6

H

4

by the addition of

1,4-bis-(phenylethynyl)benzene to 2 equiv of chlorocarbene

PhClC: generated from Ph-CHCl

2

/t-BuOK has been

reported.

22a

_{Additionally,}

1,4-bis[3,3-dimethyl-2-(tri-methylsilyl)-1-cyclopropen-1-yl]benzene was obtained

from the reaction of cyclopropenylzinc chloride and

p-diiodobenzene.

22b

_{The unsubstituted 2,2}

′

-bicyclopro-pene has been prepared,

23

_{and its structure has been}

determined by X-ray diffraction analysis at 103 K.

24

However, deprotonation of the dinuclear

bis-vi-nylidene complexes 2d and 2e, each containing an ester

substituent at C

γ

of the vinylidene ligand, yields the

bis-furyl complexes

{

[Ru]CdC(CHdC(O)OR

′

)

}

2C6H4

(R

′

)

Me, 5d; R

′

) Et, 5e) (Scheme 2). The

31

_{P NMR spectrum}

of 5d displays a singlet resonance at δ 51.2, indicating

no stereogenic carbon center.

9b 31

_{P NMR data at the}

initial stage of the reaction indicate formation of a

mixture of 5d and the bis-cyclopropenyl complex

{

[Ru]-CdC(CHCOOMe)

}

2C6H4

(3d); the latter readily converts

to 5d in solution. The less-strained five-membered ring

relative to the cyclopropenyl ligand and better oxygen

Lewis basicity are driving forces for the formation of 5.

A few organic bis-furans linked by a phenyl group have

been reported.

25

Preparation of Dinuclear Cyclopropenylium

Complex. Electrophilic addition of TCNQ

(tetracyano-quinodimethane) to two C

γ

of the bis-cyclopropenyl

ligand of 3a leads to the zwitterionic bis-vinylidene

complex

{

[Ru]dCdC(CH(TCNQ)CN)

}

2C6H4

(4a) (Scheme

3). The TCNQ-containing complex 4a displays a typical

deep purple-red color and is only moderately soluble in

DMSO. The

31

_{P NMR spectrum displays one set of}

two-doublet resonances at δ 47.2, 37.9 with JH-H

) 26.5 Hz.

Deprotonation of 4a in acetone with n-Bu4NOH in

MeOH yields

{

[Ru]CdC(C(OMe)CN)

}

2

C

6

H

4

(6a),

pos-sibly via formation of an unobserved

TCNQ-substi-tuted cyclopropenyl complex (A) (Scheme 3).

Electro-philic attack of a methoxide at CR

of the

three-mem-bered ring accompanied with removal of TCNQ is

followed by a migration of the methoxide to C

γ

to give

6a. The chemical reactivity of 6a, containing a

meth-oxy group in the three-membered ring, differs from

that of cyclopropenyl complexes with no methoxy group,

which, in the presence of acid, readily undergo

ring-opening to give vinylidene. Protonation of 6a with

HPF

6

, however, results in demethoxylation, yielding

{

[Ru]CC(CCN)

}

2C6H42+

_{(7a) without opening of the}

three-membered ring (Scheme 3). This is similar to the

reactivity of organic cyclopropene containing a methoxy

(22) (a) Eicher T.; Berneth H. Tetrahedron Lett. 1973, 2039. (b)

Untiedt S.; de Meijere, A. Chem. Ber. 1994, 127, 1511.

(23) Billups, W. E.; Haley, M. M. Angew. Chem., Int. Ed. Engl. 1989, 28, 1711.

(24) Bordalla, D.; Mootz, D.; Roese, R.; Oswald, W. J. Appl. Crytal-logr. 1985, 18, 316.

(25) (a) Pelter, A.; Rowlands, M.; Jenkins, I. H. Tetrahedron Lett. 1987, 28, 5213. (b) Teng, X.; Wada, T.; Okamoto, S.; Sato, F. Tetrahedron Lett. 2001, 42, 5501. (c) Kang, S. K.; Baik, T. G.; Song, S. Y. Synth. Lett. 1999, 3, 327. (d) Lee, C. F.; Yang, L.-M.; Hwu, T. Y.; Feng, A. S.; Tseng, J. C.; Luh, T. Y. J. Am. Chem. Soc. 2000, 122, 4992.

Scheme 2 Scheme 3

(4)

substituent.

26

_{The symmetrical planar structure of the}

three-membered ring in 7a is revealed by its

31

_{P NMR}

spectrum, which shows only a singlet resonance at δ

46.8. The reaction of

1,4-bis[3-tert-butoxylphenyl-2-phenyl-1-cyclopropen-1-yl]benzene with HClO4

resulted

in elimination of t-BuOH, leading to a

1,4-bis(diphenyl-cyclopropenylium)benzene dication.

22a

Reaction of Me

3

SiN

3

with 3a. Treatment of 3a with

more than 10-fold excess of Me

3

SiN

3

afforded 1,4-

{

[Ru]-(N4C)CH(CH2CN)

}

2C6H4

(8a) (Scheme 3). The reaction

yields diastereoisomers in a 1:1 ratio, as indicated by

two sets of two doublet resonances at δ 43.3, 41.9 and

43.1, 41.6 in the

31

_{P NMR spectrum of the product. The}

reaction may proceed via an electrophilic attack of TMS

at C

γ

of the three-membered ring followed by

nucleo-philic addition of an azide at CR

with subsequent loss

of N2

to first yield an unobserved nitrile complex

27

_(B).

Then a [2+3] cycloaddition of the coordinated nitrile

ligand with a second azide satisfactorily accounts for

formation of the product. Organic tetrazole compounds

are usually synthesized via a [3+2] cycloaddition

reac-tion of a nitrile group with azide.

28

_{Metal-coordinated}

azide ligands undergo 1,3-dipolar cycloaddition reactions

with carbon-carbon and carbon-heteroatom multiple

bonds. The metals involved are mostly Pd(II),

29

_Pt(II),

30

or Co(III),

31

_{although a whole range of other transition}

metals

32-35

_{have been used. However, formation of a}

tetrazolate ring in our ruthenium complex should not

proceed via such a pathway since the reaction of organic

nitrile with [Ru]N3

does not yield the ruthenium

tetra-zolate complex.

27

Trinuclear cyclopropenyl Complexes.

Tris-(alkynylmetal) derivatives with identical Pt(II),

36

Fe-(II),

37

_{or Ru(II)}

38

_{moieties have been synthesized from}

the reaction of 1,3,5-triethynylbenzene with appropriate

metal precursors. We use the tripodal arylalkynyl ligand

1,3,5-(HCtCC6H4CtC)3C6H3,

14a

_{which is an extended}

version of 1,3,5-triethynylbenzene. The trinuclear

acetyl-ide complex 1,3,5-

{

[Ru]CtCC6H4CtC

}

3C6H3

(9) is

pre-pared in 86% yield from the reaction of [Ru]Cl in excess

with 1,3,5-(HCtCC6H4CtC)3C6H3. In the

1

_{H NMR}

spectrum of 9 no signal for alkynyl proton is detected;

i.e., a complex with only one or two metals is not

observed. The

31

_{P NMR spectrum of 9 displays a singlet}

resonance for six equivalent phosphines at δ 50.88,

showing high symmetry of this complex. A similar

complex containing different auxiliary ligands on the

ruthenium metal center has been reported.

14

Electro-philic additions of alkyl halide RCH2X to three C

β

atoms

of bridging acetylide ligands give the tricationic

tris-vinylidene complexes 1,3,5-

{

[Ru]dCdC(CH2R)-C6H4Ct

C

}

3C6H33+

_{(R ) CN, 10a; R ) CHdCH2, 10b; R ) Ph,}

10c) (Scheme 4). Excess organic halide was used to give

the single tris-vinylidene product. The downfield

13

_{C NMR resonances at δ 345 ( 5 and}

31

_{P NMR}

resonances at δ 40 ( 2 of these complexes clearly

indicate the presence of the tris-vinylidene ligand. The

tris-vinylidene complexes 10 are readily deprotonated

by n-Bu

4

NOH, leading to the formation of 1,3,5-

{

[Ru]-CdC(CHR)C6H4CtC

}

3C6H3

(R ) CN, 11a; R ) CHd

CH2, 11b; R ) Ph, 11c) (Scheme 4). Again only a single

product is obtained; namely, no mixed

vinylidene-cyclopropenyl complex is observed. There is only one set

of AX patterns at δ 51.5 and 49.5 (d, JP-P

) 35.0 Hz) in

the

31

_{P NMR spectrum possibly due to distal}

cyclopro-penyl moieties. Tris-cycloprocyclopro-penyl complexes 11

gradu-ally decompose in air or in CDCl3, producing the

tris-acetylide complex 9 and some unidentified compounds.

Furthermore, tris-cyclopropenyl complexes are less

stable than the corresponding mono- and dinuclear

cyclopropenyl complexes. The stability of cyclopropenyl

complexes follows the trend for trinuclear < dinuclear

< mononuclear system.

Concluding Remarks. We report the preparation

of dinuclear ruthenium cyclopropenyl complexes 3a-c

by deprotonation of vinylidene complexes 2a-c.

Dia-stereomeric pairs in a 1:1 ratio are obtained. However,

the deprotonation reaction of complexes 2d,e each

containing an ester substituent at C

γ

gives the dinuclear

bis-furyl complexes 5d,e. Additionally, the

bis-methoxy-substituted cyclopropenyl complex 6a is synthesized

(26) Breslow, R.; Chang, H. W. J. Am. Chem. Soc. 1961, 83, 2367.

(b) Krebs, A. W. Angew. Chem., Int. Ed. Engl. 1965, 4, 10. (c) Closs, G. L.; Boll, W. A.; Heyn, H.; Dev, V. J. Am. Chem. Soc. 1968, 90, 173. (27) (a) Chang, K. H.; Lin, Y. C. Chem. Commun. 1998, 1441. (b) Chang, K. H.; Lin, Y. C.; Liu, Y. H.; Wang, Y. J. Chem. Soc., Dalton Trans. 2001, 3154.

(28) (a) Abbe`, G. L. Chem. Rev. 1969, 69, 345. (b) Butler, R. N. Comprehensive Heterocyclic Chemistry; Katritzky, A. R., Rees, C. W., Eds.; Pergamon: Oxford, 1984; Vol. 5, Part 4A, p 791.

(29) (a) Fehlhammer, W. P.; Beck, W. Z. Naturforsch. Teil B 1983, 38, 546. (b) Geisenberger, J.; Erbe, J.; Heidrich, J.; Nagel, U.; Beck, W. Z. Naturforsch. Teil B 1987, 42, 55.

(30) Beck, W.; Schorpp, K. Chem. Ber. 1975, 108, 3317.

(31) (a) Hsieh, B. T.; Nelson, J. H.; Milosavljevic, E. B.; Beck, W.; Kemmerich, T. Inorg. Chim. Acta 1987, 133, 267. (b) Kemmerich, T.; Nelson, J. H.; Takach, N. E.; Bohme, H. Jablonski B.; Beck, W. Inorg. Chem. 1982, 21, 1226.

(32) Blunden, S. J.; Mahon, M. F.; Molloy, K. C.; Waterfield, P. C. J. Chem. Soc., Dalton Trans. 1994, 2135.

(33) Guilard, R.; Perrot, I.; Tabard, A.; Richard, P.; Lecomte, C. Inorg. Chem. 1991, 30, 19. (b). Guilard, R.; Perrot, I.; Tabard, A.; Richard, P.; Lecomte, C. Inorg. Chem. 1991, 30, 27.

(34) Erbe, J.; Beck, W. Chem. Ber. 1983, 116, 3867.

(35) Nomiya, K.; Noguchi R.; Oda, M. Inorg. Chim. Acta 2000, 298, 24.

(36) Ohshiro, N.; Takei, F.; Onitsuka, K.; Takahashi, S. Chem. Lett. 1996, 871. (b) Khan, M. S.; Schwartz, D. J.; Pasha, N. A.; Kakkar, A. K.; Lin, B.; Raithby, R.; Lewis, J. Z. Anorg. Allg. Chem. 1992, 616, 121.

(37) Weyland, T.; Lapinte, C.; Frapper, G.; Calhorda, M. J.; Halet, J.-F.; Toupet, L. Organometallics 1997, 16, 2024. (b) Fink, H.; Long N.; J.; Martin, A. J.; Opromolla, G.; White, A. J. P.; Williams, D. J.; Zanello, P. Organometallics 1997, 16, 2646.

(38) Long, N. J.; Martin, A. J.; Biani, F. F. de; Zanello, P. J. Chem. Soc., Dalton Trans. 1998, 2017.

Scheme 4

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from the zwitterionic TCNQ-containing bis-vinylidene

complex 4a prepared from 3a. The proton-induced

demethoxylation of 6a generates 7a. The bis-tetrazolate

complex 8a is obtained from the reaction of TMSN3

with

3a. Trinuclear tris-cyclopropenyl complexes 11 are

obtained from deprotonation of trinuclear tris-vinylidene

complexes 10, which are readily prepared from 9.

Experimental Section

General Procedures. All manipulations were performed

under nitrogen using vacuum-line, drybox, and standard Schlenk techniques. CH2Cl2 was distilled from CaH2, and

diethyl ether and THF were distilled from Na/diphenylketyl. All other solvents and reagents were of reagent grade and were used as received. NMR spectra were recorded on Bruker AC-300 and DMX-500 FT-NMR spectrometers at room tempera-ture (unless stated otherwise) and are reported in units of δ with residual protons in the solvents as a standard (CDCl3, δ

7.24; C6D6, δ 7.16). FAB mass spectra were recorded on a JEOL

SX-102A spectrometer. Complex [Ru]Cl ([Ru] ) (η5_-C

5H5)(PPh3)2

-Ru) was prepared according to the literature method,39_{as were}

1,4-diethynylbenzene40 _{and 1,3,5-(HCtCC}

6H4CtC)3C6H3.14a

Elemental analyses and X-ray diffraction studies were carried out at the Regional Center of Analytical Instrument located at National Taiwan University.

Synthesis of 1,4-{[Ru]CtC}2C6H4(1). A solution of

[Ru]-Cl (230 mg, 0.32 mmol) and NaPF6(260 mg, 1.58 mmol) in

methanol (25 mL) was heated to reflux for 40 min to give an orange-red suspension, to which 1,4-diethynylbenzene (20 mg, 0.16 mmol) was added. The mixture was heated to reflux for 40 min and then cooled to room temperature. Addition of 5 equiv of sodium methoxide (86 mg) resulted in rapid precipita-tion of a yellow powder. The mixture was filtered, and the yellow solid was washed with cold methanol and dried under vacuum to give 1 (200 mg, 0.27 mmol, 84%). Spectroscopic data for 1 are as follows. 31_{P NMR (CDCl}

3): δ 50.98. 1H NMR

(CDCl3): δ 7.45-6.93 (m, 64H, Ph, C6H4), 4.29 (s, 10H, C5H5).

MS (FAB) m/z: 1506 (M+), 1244 (M+- PPh3). Anal. Calcd for

C92H74P4Ru2: C, 73.39; H, 4.95. Found: C, 73.60; H, 4.86. Synthesis of{1,4-{[Ru]dCdC(CH2CN)}2C6H4}I2(2a). To

a Schlenk flask charged with 1 (150 mg, 0.10 mmol) in CH2

-Cl2 (15 mL) was added ICH2CN (145 µL, 20 mmol). The

resulting solution was stirred at 40 °C for 24 h, then cooled to room temperature, and the solvent was reduced to about 2.5 mL. The mixture was slowly added to 25 mL of vigorously stirred diethyl ether. The red precipitate thus formed was filtered off and washed with diethyl ether and dried under vacuum to give 2a (169 mg, 0.92 mmol, 92% yield). Spectro-scopic data for 2a are as follows.31_{P NMR (CDCl}

3): δ 40.9.1H

NMR (CDCl3): δ 7.43-6.89 (m, 64H, Ph), 5.42 (s, 10H, C5H5),

3.42 (s, 4H, CH2CN).13C NMR (CD3SOCD3): δ 349.2 (t, CR, JP-C) 15.3 Hz), 134.1-129.5 (m, Ph), 124.0 (Cβ), 119.7 (CN), 96.4 (Cp), 13.4 (CH2). MS (FAB) m/z: 1713 (M+ - I). Anal.

Calcd for C96H78N2P4Ru2I2: C, 62.68; H, 4.27; N, 1.52. Found:

C, 62.44; H, 4.37; N, 1.49.

Synthesis of {1,4-{[Ru]dCdC(CH2R)}2C6H4}X2 (R ) CHdCH2, 2b; R ) Ph, 2c; R ) CO2CH3, 2d; R ) CO2C2H5, 2e). Synthesis of 2b-e followed the same procedure as that

used for the preparation of 2a from complex 1 (150 mg, 0.10 mmol). Spectroscopic data for 2b (166 mg, 0.90 mmol, 90% yield) are as follows. 31_{P NMR (CDCl}

3): δ 42.5. 1H NMR

(CDCl3): δ 7.44-6.85 (m, 64H, Ph), 5.31 (s, 10H, C5H5),

5.48-5.19 (m, 2H, dCH), 4.78 (d, 2H, J ) 5.9 Hz, dCH), 4.68 (s, 2H, dCH), 2.79 (d, 4H, CH2).13C NMR (CDCl3): δ 349.2 (t,

CR, JP-C) 15 Hz), 134.5-127.5 (m, Ph, CH2dCH), 117.3 (Cβ),

94.6 (Cp), 30.2 (CH2). MS (FAB) m/z: 1715 (M+ - I). Anal.

Calcd for C98H84P2Ru2I2: C, 62.71; H, 4.94. Found: C, 62.34;

H, 4.89. Red single crystals of 2b are obtained from the CDCl3

solution used for NMR data. Spectroscopic data for 2c (177 mg, 0.96 mmol, 96% yield) are as follows.31_{P NMR (CDCl}

3): δ 42.2.1_{H NMR (CDCl}

3): δ 7.33-6.83 (m, 74H, Ph), 5.34 (s,

10H, C5H5), 3.38 (s, 4H, CH2).13C NMR (CDCl3): δ 350.3 (t,

CR, JP-C) 15.3 Hz), 139.8-127.0 (m, Ph), 122.2 (Cβ), 95.3 (Cp), 31.8 (CH2). MS (FAB) m/z: 1767 (M+- Br). Anal. Calcd for

C106H88P4Ru2Br2: C, 68.90; H, 4.80. Found: C, 69.74; H, 4.95.

Spectroscopic data for 2d (161 mg, 0.89 mmol, 89% yield) are as follows.31_{P NMR (CDCl}

3): δ 41.9.1H NMR (CDCl3): δ

7.48-6.89 (m, 74H, Ph), 5.42 (s, 10H, C5H5), 3.23 (s, 6H, CH3), 2.92

(s, 4H, CH2).13C NMR (CDCl3): δ 349.6 (t, CR, JP-C) 15.0

Hz), 172.3 (CO2), 135.0-129.3 (Ph), 125.8 (Cβ), 95.8 (Cp), 52.6 (CH3), 31.9 (CH2). MS (FAB) m/z: 1731 (M+- Br). Anal. Calcd

for C98H84O4P4Ru2Br2: C, 64.97; H, 4.67. Found: C, 65.35; H,

4.48 Spectroscopic data of 2e (172 mg, 0.91 mmol, 91% yield) are as follows.31_{P NMR (CDCl} 3): δ 41.9.1H NMR (CDCl3): δ 7.51-6.90 (m, 74H, Ph), 5.41 (s, 10H, C5H5), 3.77 (q, 4H, JH-H ) 7.1 Hz, OCH2), 2.91 (s, 4H, CH2COO), 0.97 (t, 6H, JH-H) 7.1 Hz, CH3).13C NMR (CDCl3): δ 349.3 (t, CR, JP-C) 15.0 Hz), 171.8 (CO2), 135.0-129.4 (m, Ph), 126.0 (Cβ), 95.8 (Cp), 61.6 (CH2CO2), 32.3 (OCH2), 14.6 (CH3). MS (FAB) m/z: 1767

(M+- I). Anal. Calcd for C100H88O4P4Ru2I2: C, 62.11; H, 4.59.

Found: C, 62.37; H, 4.81.

Synthesis of 1,4-{[Ru]CdC(CHCN)}2C6H4 (3a). To a

solution of 2a (203 mg, 0.11 mmol) in 10 mL of CH2Cl2was

added NH4PF6(41 mg, 0.25 mmol). After stirring at room

temperature for 6 h, the mixture was filtered through Celite to remove NH4I, and the solvent of the filtrate was removed

under vacuum. Then 5 mL of acetone and a solution of n-Bu4

-NOH (2 mL, 1 M in MeOH) were added. The mixture was stirred for 6 h, yielding yellow microcrystalline precipitates, which were filtered off and washed with 2× 5 mL of acetone, then dried under vacuum. The product contains two diaster-eomers and is identified as 3a (148 mg, 0.94 mmol, 85% yield). Spectroscopic data for 3a are as follows.31_{P NMR (CDCl}

3): δ 51.9 (d, JP-P) 36.4 Hz), 49.3 (d, JP-P) 36.4 Hz), 51.8 (d, JP-P ) 35.2 Hz), 49.2 (d, JP-P) 35.2 Hz) (1:1).1H NMR (CDCl3): δ 7.62-6.41 (m, 64H, Ph), 4.28 (s, 10H, Cp), 1.32 (s, 2H, CH). 1_{H NMR (C} 6D6): δ 7.34-6.86 (m, 64H, Ph), 4.70, 4.69 (s, 10H, Cp), 1.72, 1.71 (s, 2H, CH).13_{C NMR (CDCl} 3): δ 140.4-128.1 (m, Ph, CR) 120.0 (CN), 86.3 (Cp), 8.8 (CH). MS (FAB) m/z: 1585 (M++ 1), 1324 (M+- PPh3), 1061 (M+- 2PPh3). Anal.

Calcd for C96H76N2P4Ru2: C, 72.81; H, 4.84; N, 1.77. Found:

C, 72.69; H, 4.91; N, 1.81.

Synthesis of 1,4-{[Ru]CdC(CHCHdCH2)}2C6H4 (3b).

Complex 3b (155 mg, 0.098 mmol, 65% yield) was prepared from 2b (276 mg, 0.15 mmol) in analogy with the synthesis of

3a. Spectroscopic data for 3b are as follows.31_{P NMR (C} 6D6): δ 53.2 (d, JP-P) 37.3 Hz), 49.7 (d, JP-P) 37.3 Hz), 53.1 (d, JP-P) 36.9 Hz), 49.5 (d, JP-P) 36.9 Hz), (1:1).1H NMR (C6D6): δ 7.46-6.84 (m, 74H, Ph), 6.30-6.16 (m, 2H, dCH), 5.63, 5.62 (dd, JH-H) 17.0, 2.5 Hz, 2H, dCH), 5.13, 5.12 (dd, JH-H) 10.0, 2.5 Hz, 2H, dCH), 4.67 (s, 10H, Cp), 2.46, 2.45 (d, JH-H ) 8.6 Hz, 2H, CH2).13C NMR (C6D6): δ 154.6 (dCH), 141.2-123.6 (m, Ph, CR), 106.4 (dCH2), 86.2 (Cp), 33.5 (CH). MS (FAB) m/z: 1587 (M++ 1), 1547 (M++ 1 - CHCHdCH2), 1326

(M++ 1 - PPh3). Anal. Calcd for C98H82P4Ru2: C, 74.23; H,

5.21. Found: C, 74.01; H, 5.33.

Synthesis of 1,4-{[Ru]CdC(CHPh)}2C6H4(3c). Complex 3c (121 mg, 0.072 mmol, 55% yield) was prepared from 2c (240

mg, 0.13 mmol) in analogy with the synthesis of 3a. Spectro-scopic data for 3c are as follows.31_{P NMR (C}

6D6): δ 54.8 (d, JP-P) 36.8 Hz), 48.2 (d, JP-P) 36.8 Hz), 54.8 (d, JP-P) 37.0 Hz), 48.1 (d, JP-P) 37.0 Hz) (1:1).1H NMR (C6D6): δ 7.70-6.80 (m, 74H, Ph), 4.43, 4.40 (s, 10H, Cp), 2.87, 2.86 (s, 2H, CH).13_{C NMR (CDCl} 3): δ 141.2-123.6 (m, Ph, CR), 86.1 (Cp),

(39) Bruce, M. I.; Hameister, C. A. Swincer G.; Wallis, R. C. Inorg. Synth. 1990, 28, 270.

(40) Pelter, A.; Jones, D. E. J. Chem. Soc., Perkin Trans. 1 2000, 2289.

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33.9 (CH). Anal. Calcd for C106H86P4Ru2: C, 75.51; H, 5.14.

Found: C, 75.82; H, 5.06.

Synthesis of{[Ru]CdC(CHdC(O)OR)}2C6H4(R ) Me, 5d; R ) Et, 5e). The synthesis and workup were similar to

those used in the preparation of complex 3a. Complex 5d (119 mg, 0.072 mmol, 80% yield) was prepared from 2d (163 mg, 0.09 mmol). Spectroscopic data for 5d are as follows.31_{P NMR}

(CDCl3): δ 51.2.1H NMR (CDCl3): δ 7.25-6.99 (m, 64H, Ph),

5.06 (s, 2H, CH), 4.10 (s, 10H, Cp), 3.04 (s, 6H, OCH3).13C

NMR (CDCl3): δ 163.9 (CO2), 155.0 (CR), 140.6-127.1 (Ph),

87.1 (Cγ), 84.00 (Cp), 58.1 (CH3). Anal. Calcd for C98H82O4P4

-Ru2: C, 71.35; H, 5.01. Found: C, 71.50; H, 4.89. Complex 5e

(110 mg, 0.066 mmol, 82% yield) was prepared from 2e (151 mg, 0.08 mmol). Spectroscopic data for 5e are as follows.31_P

NMR (CDCl3): δ 51.7.1H NMR (CDCl3): δ 7.35-6.96 (m, 64H,

Ph), 5.11 (s, 2H, CH), 4.11 (s, 10H, Cp), 3.10 (q, JH-H) 7.07

Hz, 4H, OCH2), 0.93 (t, JH-H) 7.07 Hz, 6H, CH3).13C NMR

(CDCl3): δ 163.2 (CO2), 155.3(CR), 141.6-127.7 (Ph), 89.6 (Cγ), 84.5 (Cp), 67.3 (CH2), 15.4 (CH3). Anal. Calcd for C100H86O4P4

-Ru2: C, 71.59; H, 5.17. Found: C, 71.40; H, 5.30.

Reaction of 3a with TCNQ. To a mixture of 3a (40 mg,

0.025 mmol) in CH2Cl2(5 mL) was added TCNQ (10 mg, 0.05

mmol). The solution was stirred at room temperature for 40 min, and the solvent was removed under vacuum. The residue was washed with 3× 5 mL of methanol to produce the purple-red powder 4a (46 mg, 0.023 mmol, 92% yield). Spectroscopic data for 4a are as follows.31_{P NMR (d}

6-DMSO): δ 47.2, 37.9

(2d, JP-P) 26.5 Hz).1H NMR (d6-DMSO): δ 7.62-6.9 (m, Ph),

5.50 (s, Cp).

Synthesis of 1,4-{[Ru]CdC(C(OMe)CN)}2C6H4(6a). To

a solution of 4a (120 mg, 0.06 mmol) in 7 mL of acetone was added 0.7 mL of CH3OH/n-Bu4NOH (1 M in MeOH). The color

of the solution immediately changed to dark green. The solution was further stirred at room temperature for 1.5 h, and then the solvent was removed under vacuum. The residue was washed with 3× 5 mL of methanol to produce yellow-green microcrystals of complex 6a (76 mg, 0.046 mmol, 77% yield). Spectroscopic data for 6a are as follows. 31_{P NMR}

(CDCl3): δ 51.9 (d, JP-P) 36.4 Hz), 49.9 (d, JP-P) 36.4 Hz),

51.2 (d, JP-P) 36.4 Hz), 49.3 (d, JP-P) 36.4 Hz) (1:1).1H NMR

(CDCl3): δ 7.16-6.39 (m, 64H, Ph), 4.65 (s, 10H, Cp), 3.42, 3.38

(s, 6H, OMe).1_{H NMR (C}

6D6): δ 7.44-6.68 (m, 64H, Ph), 4.89

(s, 10H, Cp), 3.61 (s, 3H, OMe), 3.59 (s, 3H, OMe). MS (FAB)

m/z: 1644 (M+_{), 1618 (M}+_{- CN).}13_{C NMR (CDCl}

3): δ

139.5-126.7 (Ph, CR), 86.3 (Cp), 59.3, 59.1 (C(CN)(OMe)), 55.7, 55.5

(OMe). Anal. Calcd for C98H80O2N2P4Ru2: C, 71.61; H, 4.91;

N, 1.70. Found: C, 71.42; H, 4.99; N, 1.73.

Reaction of 6a with HPF6. To a solution of 6a (30 mg,

0.018 mmol) in 2 mL of CH2Cl2at 0 °C was added 2.5 µL of

HPF6(60 wt % in H2O). The color of the solution immediately

changed from yellow to amber-red. The solution was stirred at 0 °C for 10 min and then was added to 10 mL of an ether solution in an ice-bath. The orange precipitate thus formed was filtered and washed with diethyl ether to give the product {[Ru]CC(C(CN))}2C6H4(PF6)2(7a). Spectroscopic data for 7a

are as follows.31_{P NMR (C}

6D6): δ 46.79.1H NMR (C6D6): δ

7.67-6.89 (m, 74H, Ph), 5.20 (s, 10H, Cp).

Synthesis of 1,4-{[Ru]N4CCH(CH2CN)}2C6H4(8a). To a

solution of complex 3a (30 mg, 0.019 mmol) in THF (3 mL) was added (CH3)3SiN3(30 µL, 0.23 mmol). After stirring at

room temperature for 7 h, the mixture was concentrated to ca. 1 mL and slowly added to vigorously stirred hexane (8 mL). The yellow precipitate thus formed was filtered off and washed with 2× 5 mL of hexane. The product was analytically pure and was identified as complex 8a (24 mg, 0.014 mmol, 75% yield). Spectroscopic data for 8a are as follows. 31_{P NMR}

(C6D6): δ 43.3, 41.9 (d, JP-P) 38.4 Hz) 43.1, 41.6 (d, JP-P) 38.2 Hz) (1:1).1_{H NMR (C} 6D6): δ 7.41-6.74 (m, 64H, Ph), 4.49, 4.43 (dd, 2H,3_J H-H) 7.75, 3JH-H) 7.84 Hz), 4.29 (s, 10H, Cp), 2.77-2.63, 2.47-2.36 (m, 4H, CH2).13C NMR (CDCl3): δ 163.9 (NCN), 138.3-123.6 (Ph), 118.7 (CN), 83.1 (Cp), 39.6, 39.5 (CH), 23.7, 23.5 (CH2). MS (FAB) m/z: 1700 (M+) 1437 (M+_{- PPh}

3) 1176 (M+- 2PPh3). Anal. Calcd for C96H78N10P4

-Ru2: C, 67.91; H, 4.63; N, 8.25. Found: C, 68.02; H, 4.54; N,

8.20.

Synthesis of 1,3,5-{[Ru]CtCC6H4CtC}3C6H3(9).

Com-plex [Ru]Cl (290 mg, 0.04 mmol) in methanol (25 mL) was heated to reflux for 40 min to give an orange-red solution, to which 1,3,5-(HCtCC6H4CtC)3C6H3(60 mg, 0.13 mmol) was

then added. The mixture was stirred and heated to reflux for 1 h and then cooled to room temperature. Addition of 10 equiv of triethylamine resulted in rapid precipitation of a yellow powder. The mixture was stirred for 1 h and filtered, and the yellow solid washed with cold methanol to give 9 (289 mg, 0.034 mmol, 86% yield). Spectroscopic data for 9 are as follows.

31_{P NMR (CDCl}

3): δ 50.88.1H NMR (CDCl3): δ 7.56-7.03 (m,

105H, Ph), 4.32 (s, 15H, Cp).13_{C NMR (CDCl}

3): δ 138.7 (t,

CR, JP-C) 20.9 Hz), 133.8-127.2 (Ph), 85.3 (Cp), 115.3 (tC),

91.5, 88.2 (tC). MS (FAB) m/z: 2521(M++ 1). Anal. Calcd for C159H120P6Ru3: C, 75.79; H, 4.80. Found: C, 75.92; H, 4.64.

Preparation of{1,3,5-{[Ru]dCdC(CH2CN)C6H4CtC}3C6 -H3}I3(10a). A Schlenk flask was charged with 9 (330 mg,

0.131 mmol) in 7 mL of CH2Cl2, and ICH2CN (282 µL 3.9

mmol) was added under nitrogen. The resulting solution was stirred at 40 °C for 24 h, then cooled to room temperature, and the solvent was reduced to about 2.5 mL. The mixture was slowly added to 25 mL of vigorously stirred diethyl ether. The pale red precipitate thus formed was filtered off and washed with diethyl ether, then dried under vacuum to give

10a (364 mg, 0.120 mmol, 92% yield). Spectroscopic data for 10a are as follows. 31_{P NMR (CDCl}

3): δ 40.94. 1H NMR

(CDCl3): δ 7.62-6.92 (m, 105H, Ph), 5.38 (s, 15H, Cp), 3.55 (s,

6H, CH2).13C NMR (CD3SOCD3): δ 345.7 (t, CR, JP-C) 15.0

Hz), 134.4-129.5 (m, Ph), 124.0 (Cβ), 119.7 (CN), 96.2 (Cp), 91.1, 88.8 (tC), 13.4 (CH2). Anal. Calcd for C165H126N3P6

-Ru3I3: C, 65.61; H, 4.20; N, 1.39. Found: C, 65.35; H, 4.31; N,

1.31.

Preparation of{1,3,5-{[Ru]dCdC(CH2CHdCH2)C6H4Ct C}3C6H3}I3(10b). Complex 10b (376 mg, 0.120 mmol, 92%

yield) was prepared from 9 (330 mg, 0.131 mmol) and ICH2

-CHdCH2in analogy with the synthesis of 10a. Spectroscopic

data for 10b are as follows. 31_{P NMR (CDCl}

3): δ 42.35. 1H NMR (CDCl3): δ 7.76-6.87 (m, 105H, Ph), 5.67-5.53 (m, 3H, dCH), 5.17 (s, 15H, C5H5), 5.01 (d, 3H, J ) 9.9 Hz, dCH2), 4.93 (d, 3H, J ) 17.1 Hz, dCH2), 2.79 (d, 4H, J ) 8.6 Hz, CH2). 13_{C NMR (CDCl} 3): δ 349.0 (t, CR, JP-C) 15.5 Hz), 140.6-122.9 (m, Ph), 117.9 (Cβ), 94.8 (Cp), 90.6, 88.9 (tC), 30.7 (CH2). Anal.

Calcd for C168H135P6Ru3I3: C, 66.73; H, 4.50. Found: C, 66.91;

H, 4.68.

Preparation of{1,3,5-{[Ru]dCdC(CH2Ph)C6H4CtC}3C6 -H3}Br3(10c). Complex 10c (354 mg, 0.117 mmol, 89% yield)

was prepared from 9 (330 mg, 0.131 mmol) and BrCH2Ph in

analogy with the synthesis of 10a. Spectroscopic data for 10c are as follows.31_{P NMR (CDCl} 3): δ 42.10.1H NMR (CDCl3): δ 7.57-6.90 (m, 120H, Ph), 5.21 (s, 15H, Cp), 3.59 (s, 6H, CH2). 13_{C NMR (CDCl} 3): δ 348.6 (t, CR, JP-C) 15.8 Hz), 137.7-126.7 (m, Ph), 122.0 (Cβ), 94.7 (Cp), 90.9, 88.6 (tC), 31.8 (CH2). Anal.

Calcd for C180H141P6Ru3Br3: C, 71.28; H, 4.69. Found: C, 71.62;

H, 4.55.

Preparation of{1,3,5-{[Ru]CdC(CHR)C6H4CtC}3C6H3} (11a, R ) CN). To a solution of 10a (302 mg, 0.10 mmol) in

10 mL of CH2Cl2was added NH4PF6(82 mg, 0.5 mmol). After

stirring at room temperature for 6 h, the mixture was filtered through Celite and the solvent was removed by vacuum. Then 4 mL of acetone and a solution of n-Bu4NOH (2 mL, 1 M in

MeOH) were added. After stirring for 8 h, the solvent was reduced to about 1.5 mL. The mixture was slowly added to 8 mL of vigorously stirred CH3CN. The yellow precipitate thus

formed was filtered off, washed with CH3CN, and dried under

vacuum to give 11a (217 mg, 0.082 mmol, 82%). Spectroscopic

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data for 11a are as follows.31_{P NMR (CDCl} 3): δ 51.5, 49.5 (d, JP-P) 35.0 Hz).1H NMR (CDCl3): δ 7.56-6.54 (m, 71H, Ph), 4.58 (s, 15H, Cp), 1.48 (s, 3H, CH).13_{C NMR (CDCl} 3): δ 138.6-127.4 (Ph), 122.3 (CN), 116.4 (tC), 90.7, 85.2 (tC), 86.5 (Cp), 8.13 (CH). Anal. Calcd for C165H123N3P6Ru3: C, 75.16; H, 4.07;

N, 1.59. Found: C, 75.43; H, 4.21; N, 1.44.

Complex 11b (R ) CHdCH2) (198 mg, 0.075 mmol, 75% yield) was prepared from 10b (302 mg, 0.10 mmol) in analogy with the synthesis of 11a. Spectroscopic data for 11b are as follows.31_{P NMR (C} 6D6): δ 53.0, 49.5 (d, JP-P) 36.5 Hz).1H NMR (C6D6): δ 7.61-6.84 (m, 71H, Ph), 6.34-6.22 (m, 3H, d CH), 5.73 (dd, JH-H) 17.0, 2.5 Hz, 2H, dCH2) 5.22 (dd, JH-H ) 10.0, 2.5 Hz, 2H, dCH2) 4.69 (s, 15H, Cp), 2.57 (d, JH-H) 8.6 Hz, 3H, CH).13_{C NMR (CDCl} 3): δ 153.1 (dCH), 143.1 (t, CR, JP-C) 20.7 Hz), 140.2-123.6 (Ph), 117.2 (Cβ), 106.4 (d CH2), 91.8, 87.4 (tC), 85.8 (Cp), 32.9 (CH). Anal. Calcd for

C168H132P6Ru3: C, 76.43; H, 5.04. Found: C, 76.98; H, 4.82. Complex 11c (R ) Ph) (173 mg, 0.062 mmol, 62% yield)

was prepared from 10c (303 mg, 0.10 mmol) in analogy with the synthesis of 11a. Spectroscopic data for 11c are as follows.

31_{P NMR (C} 6D6): δ 54.4, 47.6 (d, Jp-p) 36.7 Hz). 1H NMR (C6D6): δ 7.68-6.85 (m, 86H, Ph), 4.43 (s, 15H, Cp), 3.0 (s, 3H, CH).13_{C NMR (CDCl} 3): δ 143.1(t, CR, JP-C) 20.1 Hz), 140.6-127.4 (Ph), 117.2(Cβ), 91.8, 87.5 (tC), 85.3 (Cp), 33.0 (CH). Anal. Calcd for C180H138P6Ru3: C, 77.49; H, 4.99. Found: C,

77.26; H, 4.84.

Single-Crystal X-ray Diffraction Analysis of 2b. Single

crystals of 2b suitable for an X-ray diffraction study were grown as mentioned above. A single crystal of dimensions 0.40 × 0.20 × 0.15 mm3_{was glued to a glass fiber and mounted on}

an SMART CCD diffractometer. The diffraction data were collected using 3 kW sealed-tube molybdenum KR radiation (T ) 295 K). Exposure time was 5 s per frame. SADABS (Siemens area detector absorption) absorption correction was applied, and decay was negligible. Data were processed, and the structures were solved and refined by the SHELXTL program. The structure was solved using direct methods and confirmed by Patterson methods refining on intensities of all data (67 315 reflections) to give R1 ) 0.0531 and wR2 ) 0.1325 for 12 547 unique observed reflections (I > 2σ(I)). Hydrogen atoms were placed geometrically using the riding model with thermal parameters set to 1.2 times that for the atoms to

which the hydrogen is attached and 1.5 times that for the methyl hydrogens. (Data collection parameters are listed in Table 2.)

Acknowledgment. We thank the National Science

Council, Taiwan, Republic of China, for support of this

work.

Supporting Information Available: Tables of atomic

coordinates, bond lengths and angles, anisotropic thermal parameters, and hydrogen atom positions for 2b. This material is available free of charge via the Internet at http://pubs.acs.org. OM020913X

Table 2. Crystal and Intensity Collection Data for 1,4-{[Ru]CdC(CH2CHdCH2)}2C6H42+(2b) mol formula C104H84D6Cl18I2P4Ru2

mol wt 2563.68

cryst syst triclinic

space group P1h a, Å 9.5660(1) b, Å 15.2030(1) c, Å 20.8060(2) R, deg 101.413(1) β, deg 103.079(1) γ, deg 103.824(1) V, Å3 _2758.58(4) Z 1 cryst dimens, mm3 _0.40_{× 0.20 × 0.15} Mo KR radiation: γ, Å 0.71073 θ range, deg 1.04-27.47 limiting indices -12 e h e 12 -19 e k e 19 -26 e l e 26 no. of reflns collected 67 315 no. of ind reflns (Rint) 12 612 (0.0760)

max. and min. transmn 0.874 and 0.653

refinement method full-matrix least-squares on F2

no. of data/restraints/params 12547/0/587

GOF 1.020

final R indices [I > 2σ(Ι)] R1 ) 0.0531, wR2) 0.1325 R indices (all data) R1 ) 0.0936, wR2) 0.1630

∆F (in final map), e/Å-3 -0.888 and +0.967