Synthesis of the first family of rhodium(I) perfluoroalkyl complexes from rhodium(I) fluoro complexes

Article abstract of DOI:10.1021/om049592a

The rhodium(I) fluoro complexes [RhF(COD)(PR₃)] (R = Ph (1a), C₆H₄OMe-4 (1b), i-Pr (1d), Cy (1e); COD = 1,5-cyclooctadiene) react with Me₃SiR_F to afford the rhodium(I) perfiuoroalkyl complexes [Rh(R_F)(COD)(PR₃)] (R_F = CF₃, R = Ph (2a), C₆H₄OMe-4 (2b), i-Pr (2d), Cy (2e); R_F = n-C₃F₇, R = Ph (2c)), of which 2a,c were isolated as pure solids. [Rh-(CF₃)(NBD) PPh₃)] (3) was prepared by reaction of 2a with norbornadiene. The reactions of 2a-c with 2,6-dimethylphenyl isocyanide (XyNC) or t-BuNC, in a 1:2 molar ratio, gave the compounds tarns-[Rh(R_F)CNR′) ₂(PR₃)] (R_F = CF₃, R′ = Xy, R = Ph (4a), C₆H₄OMe-4 (4b); R_F = CF₃) R′ = t-Bu, R = Ph (4a′); R_F = n-C₃F ₇, R′ = Xy, R = Ph (4c)). The reactions of 2a-c with an equimolar amount of XyNC gave mixtures containing complexes 4a-c as the major products. The peroxo complexes [Rh(CF₃)(η²-O ₂)(CNXy)₂(PR₃)], (R = Ph (7a), C ₆H₄OMe-4 (7b)) were isolated by reacting O₂ with 4a,b, respectively. The complexes [Rh(R_F)(CNR′) _3- (PR₃)] (R_F = CF₃, R′ = Xy, R = Ph (8a), C₆H₄OMe-4 (8b); R_F = n-C ₃F₇, R′ = Xy, R = Ph (8c)) were obtained by reaction of 2a-c with 3 equiv of XyNC. Formation of [Rh(CF₃)PPh ₃)-(CO)₃] (9) in the reaction of complex 2a with CO was spectroscopically observed. The crystal structures of complexes 4a, 7a, and 8a have been determined by single-crystal X-ray diffraction studies. The dynamic behavior in solution of the prepared complexes was studied by variable-temperature NMR.

Full text of DOI:10.1021/om049592a

Organometallics 2004, 23, 4871-4881
4871
Syn th esis of th e F ir st F a m ily of Rh od iu m (I)
P er flu or oa lk yl Com p lexes fr om Rh od iu m (I) F lu or o
Com p lexes1
J ose´ Vicente,*,† J uan Gil-Rubio,*,† J uan Guerrero-Leal,† and Delia Bautista‡
Grupo de Quı´mica Organometa´lica, Departamento de Qu´ımica Inorga´nica, Facultad de
Quı´mica, Universidad de Murcia, Apartado 4021, 30071 Murcia, Spain, and SACE,
Universidad de Murcia, Apartado 4021, 30071 Murcia, Spain
Received J une 7, 2004
The rhodium(I) fluoro complexes [RhF(COD)(PR3)] (R ) Ph (1a ), C6H4OMe-4 (1b), i-Pr
(1d ), Cy (1e); COD ) 1,5-cyclooctadiene) react with Me3SiRF to afford the rhodium(I)
perfluoroalkyl complexes [Rh(RF)(COD)(PR3)] (RF ) CF3, R ) Ph (2a ), C6H4OMe-4 (2b), i-Pr
(2d ), Cy (2e); RF ) n-C3F7, R ) Ph (2c)), of which 2a ,c were isolated as pure solids. [Rh-
(CF3)(NBD)(PPh3)] (3) was prepared by reaction of 2a with norbornadiene. The reactions of
2a -c with 2,6-dimethylphenyl isocyanide (XyNC) or t-BuNC, in a 1:2 molar ratio, gave the
compounds trans-[Rh(RF)(CNR′)2(PR3)] (RF ) CF3, R′ ) Xy, R ) Ph (4a ), C6H4OMe-4 (4b);
RF ) CF3, R′ ) t-Bu, R ) Ph (4a ′); RF ) n-C3F7, R′ ) Xy, R ) Ph (4c)). The reactions of 2a -c
with an equimolar amount of XyNC gave mixtures containing complexes 4a -c as the major
products. The peroxo complexes [Rh(CF3)(η2-O2)(CNXy)2(PR3)], (R ) Ph (7a ), C6H4OMe-4
(7b)) were isolated by reacting O2 with 4a ,b, respectively. The complexes [Rh(RF)(CNR′)3-
(PR3)] (RF ) CF3, R′ ) Xy, R ) Ph (8a ), C6H4OMe-4 (8b); RF ) n-C3F7, R′ ) Xy, R ) Ph (8c))
were obtained by reaction of 2a -c with 3 equiv of XyNC. Formation of [Rh(CF3)(PPh3)-
(CO)3] (9) in the reaction of complex 2a with CO was spectroscopically observed. The crystal
structures of complexes 4a , 7a , and 8a have been determined by single-crystal X-ray
diffraction studies. The dynamic behavior in solution of the prepared complexes was studied
by variable-temperature NMR.
In tr od u ction
alkyl iodides or bromides to low-valent metal complexes,
(b) decarbonylation of perfluoroacyl complexes, and (c)
transmetalation reactions.6,9,10 Method a is not suitable
for the synthesis of complexes in low oxidation states,
and method b is quite specific and frequently requires
heating at high temperatures.9 A limitation of method
c is the instability of the (perfluoroalkyl)lithium and
-magnesium reagents,11 especially for the trifluorometh-
yl derivatives, which has been solved by the use of toxic
(trifluoromethyl)cadmium or -mercury compounds.6,10
The selective functionalization of perfluoroorganic
compounds is a major challenge in chemistry and,
particularly, in organometallic and coordination chem-
istry.2 Transition-metal perfluoroalkyl complexes are
relevant in this context, due to the higher reactivity of
the C-F bond in a position R to the metal with respect
to perfluorocarbons.3-7 Hence, the study of the reactivity
of perfluoroalkyl complexes may play an important role
in the development of new reactions which allow the
substitution of fluorine by different functional groups
in perfluorocarbons.3,8
(5) Hughes, R. P.; Willemsen, S.; Williamson, A.; Zhang, D. Orga-
nometallics 2002, 21, 3085-3087. Albietz, P. J ., J r.; Houlis, J . F.;
Eisenberg, R. Inorg. Chem. 2002, 41, 2001-2003. Hughes, R. P.; Zhang,
D.; Zakharov, L. N.; Rheingold, A. L. Organometallics 2002, 21, 4902-
4904. Hughes, R. P.; Smith, J . M.; Incarvito, C. D.; Lam, K.-C.;
Rhatigan, B.; Rheingold, A. L. Organometallics 2002, 21, 2136-2144.
Hughes, R. P.; Kovacik, I.; Lindner, D. C.; Smith, J . M.; Willemsen,
S.; Zhang, D.; Guzei, I. A.; Rheingold, A. L. Organometallics 2001, 20,
3190-3197. Hughes, R. P.; Smith, J . M. J . Am. Chem. Soc. 1999, 121,
6084-6085. Michelin, R. A.; Ros, R.; Guadalupi, G.; Bombieri, G.;
Benetollo, F.; Chapuis, G. Inorg. Chem. 1989, 28, 840-846. Michelin,
R. A.; Facchin, G.; Ros, R. J . Organomet. Chem. 1985, 279, C25-C28.
(6) Brothers, P. J .; Roper, W. R. Chem. Rev. 1988, 88, 1293-1326.
(7) Huang, D.; Koren, P. R.; Folting, K.; Davidson, E. R.; Caulton,
K. G. J . Am. Chem. Soc. 2000, 122, 8916-8931. Huang, D.; Caulton,
K. G. J . Am. Chem. Soc. 1997, 119, 3185-3186.
(8) Richmond, T. G. Angew. Chem., Int. Ed. 2000, 39, 3241-3244.
Burdeniuc, J .; J edlicka, B.; Crabtree, R. H. Chem. Ber./ Recl. 1997,
130, 145-154.
(9) Bruce, M. I.; Stone, F. G. A. Fluorocarbon Complexes of Transi-
tion Metals. In Preparative Inorganic Reactions; J olly, W. L., Ed.;
Interscience: Bristol, U.K., 1968; Vol. 4, pp 177-235.
(10) Morrison, J . A. Adv. Organomet. Chem. 1993, 35, 211-239.
(11) Chambers, R. C. Fluorine in Organic Chemistry; Wiley-Inter-
science: New York, 1973. Burton, D. J .; Lu, L. Top. Curr. Chem. 1997,
193, 45-89.
The classical methods for the synthesis of perfluoro-
alkyl complexes are (a) oxidative addition of perfluoro-
* To whom correspondence should be addressed. Tel and fax: 34
968 364143. E-mail: jvs@um.es (J .V.), jgr@um.es (J .G.-R.). Web
address: http://www.um.es/gqo/.
† Departamento de Qu´ımica Inorga´nica.
‡ SACE.
(1) Synthesis and Reactivity of Fluoro Complexes. 3. Part 2: Vicente,
J .; Gil-Rubio, J .; Bautista, D.; Sironi, A.; Masciocchi, N. Inorg. Chem.
2004, 43, 5665-5675.
(2) Lemal, D. M. J . Org. Chem. 2004, 69, 1-11. Saunders, G. C.
Angew. Chem., Int. Ed. Engl. 1996, 35, 2615-2617. MacNicol, D. D.;
Robertson, C. D. Nature 1988, 332, 59-61. Mazurek, U.; Schwarz, H.
Chem. Commun. 2003, 1321-1326. Richmond, T. G. Top. Organomet.
Chem. 1999, 3, 243-269.
(3) Kiplinger, J . L.; Richmond, T. G.; Osterberg, C. E. Chem. Rev.
1994, 94, 373-431.
(4) Hughes, R. P.; Lindner, D. C.; Liable-Sands, L. M.; Rheingold,
A. L. Organometallics 2001, 20, 363-366. Hughes, R. P.; Lindner, D.
C. J . Am. Chem. Soc. 1997, 119, 11544-11545.
10.1021/om049592a CCC: $27.50 © 2004 American Chemical Society
Publication on Web 09/14/2004

4872 Organometallics, Vol. 23, No. 21, 2004
Vicente et al.
Sch em e 1
The reactions between fluoro complexes and silanes
of general formula Me3SiR allow the substitution of
fluorine by a wide variety of R groups under very mild
conditions.12,13 In particular, Me3SiCF3 has been suc-
cessfully used to transfer a CF3 group to Ru7 and Ti14
centers by reaction with the corresponding fluoro com-
plexes. We have preliminarily reported its use, for the
first time, to prepare a Rh(I) trifluoromethyl complex.15
Despite the fact that numerous examples of Rh(III)
perfluoroalkyl complexes have been reported,4,9,16-19 the
chemistry of Rh(I) perfluoroalkyls has been virtually
unexplored. To the best of our knowledge, the only
reported example is trans-[Rh(CF3)(CO)(PPh3)2], which
was prepared by Roper and co-workers by reaction of
[RhH(CO)(PPh3)3] with Hg(CF3)2.16 Related complexes
ucts were formed from which 2d ,e could not be sepa-
rated. Treatment of 2a with excess of norbornadiene
(NBD) gave [Rh(CF3)(NBD)(PPh3)] (3).
21
are trans-[Rh(CF2CF2H)L(PPh3)2] (L ) CO,20 PF3
)
which were obtained by reaction of [RhH(CO)(PPh3)3]
with tetrafluoroethylene. We have preliminarily re-
ported that the reaction between [RhF(COD)(PPh3)] and
Me3SiCF3 afforded cleanly the trifluoromethyl complex
[Rh(CF3)(COD)(PPh3)].15 Herein, we describe the syn-
thesis of a series of Rh(I) perfluoroalkyl complexes by
using the same method and their reactivity toward
isocyanides and CO.
Complexes 2a ,c and 3 were isolated as orange solids
in good yields and characterized by analytical and
spectroscopical methods. In addition, compound 2a was
also characterized by a single-crystal X-ray diffraction
study.15 Complex 2b could be characterized only by
NMR spectroscopy in solution, because it was always
isolated along with tris(4-methoxyphenyl)phosphine
oxide. Nevertheless, in situ prepared solutions of 2b as
well as of 2a ,c were used successfully in further reac-
tions (see below).
To synthesize a family of Rh(I) trifluoromethyl com-
plexes and to study the reactivity of the Rh-C bond
toward unsaturated organic molecules that could lead
to new C-C bond formation reactions involving the RF
group, the reactions of 2a -c with isocyanides and CO
were studied.
The products of the reactions with 2,6-dimethylphenyl
isocyanide (XyNC) were dependent on the isocyanide/
Rh complex molar ratio used. Thus, when complexes
2a -c were treated with an equimolar amount of XyNC
(Scheme 2), the main reaction products were trans-[Rh-
(RF)(CNXy)2(PR3)] (RF ) CF3, R ) Ph (4a ), C6H4OMe-4
(4b); RF ) n-C3F7, R ) Ph (4c)), together with unreacted
starting complexes. In addition, in the reaction with
2a ,b, complexes [Rh(CF3)(CNXy)(COD)] (5) and trans-
[Rh(CF3)(CNXy)(PR3)2] (R ) Ph (6a ) and R ) C6H4-
OMe-4 (6b), respectively), were detected in minor
amounts. Despite the fact that these mixtures could not
be separated, the presence of 4a -c could be unambigu-
ously determined, because these complexes were iso-
lated by reaction of 2a -c with XyNC in a 1:2 molar ratio
(see below). The structures of complexes 5 and 6a ,b were
proposed on the basis of their NMR signals in the
reaction mixture (see NMR and IR Spectroscopy). To
obtain additional support for the assignation of the
structures of compounds 6a ,b, the synthesis of 6a was
attempted by reaction of 2a with equimolar amounts of
XyNC and PPh3. However the reaction gave a mixture
which could not be separated.
Resu lts a n d Discu ssion
Syn th esis. The complexes [RhF(COD)(PR3)],1 where
R ) Ph (1a ), C6H4OMe-4 (1b), i-Pr (1d ), Cy (1e), react
at room temperature with Me3SiRF to give the perfluo-
roalkyl derivatives [Rh(RF)(COD)(PR3)] (RF ) CF3, R )
Ph (2a ), C6H4OMe-4 (2b), i-Pr (2d ), Cy (2e); RF
)
n-C3F7, R ) Ph (2c)) (Scheme 1). While the reactions
leading to 2a -c were complete after a few minutes, the
reactions of the trialkylphosphine complexes 1d ,e with
Me3SiCF3 were remarkably slower (the 2d :1d and 2e:
1e ratios determined by 19F NMR were 2 and 1.5,
respectively, after 24 h), probably due to the steric
hindrance of P(i-Pr)3 and PCy3. In addition, owing to
the instability of 2d ,e in solution, decomposition prod-
(12) Veltheer, J . E.; Burger, P.; Bergman, R. G. J . Am. Chem. Soc.
1995, 117, 12478-12488.
(13) Cooper, A. C.; Huffman, J . C.; Caulton, K. G. Inorg. Chim. Acta
1998, 270, 261-272. Hoffman, N. W.; Prokopuk, N.; Robbins, M. J .;
J ones, C. M.; Doherty, N. M. Inorg. Chem. 1991, 30, 4177-4181. Braun,
T.; Parsons, S.; Perutz, R. N.; Voith, M. Organometallics 1999, 18,
1710-1716. Doherty, N. M.; Critchlow, S. C. J . Am. Chem. Soc. 1987,
109, 7906-7908.
(14) Taw, F. L.; Scott, B. L.; Kiplinger, J . L. J . Am. Chem. Soc. 2003,
125, 14712-14713.
(15) Vicente, J .; Gil-Rubio, J .; Bautista, D. Inorg. Chem. 2001, 40,
2636-2637.
(16) Burrell, A. K.; Clark, G. R.; J effrey, J . G.; Rickard, C. E. F.;
Roper, W. R. J . Organomet. Chem. 1990, 388, 391-408.
(17) Bowden, A. A.; Hughes, R. P.; Lindner, D. C.; Incarvito, C. D.;
Liable-Sands, L. M.; Rheingold, A. L. J . Chem. Soc., Dalton Trans.
2002, 3245-3252.
(18) Hughes, R. P.; Le Husebo, T. Organometallics 1997, 16, 5-7.
Hyde, E. M.; Kennedy, J . D.; Shaw, B. L.; McFarlane, W. J . Chem.
Soc., Dalton Trans. 1977, 1571-1576. Van der Boom, M. E.; Ben-David,
Y.; Milstein, D. J . Am. Chem. Soc. 1999, 121, 6652-6656. Oliver, A.
J .; Graham, W. A. G. Inorg. Chem. 1971, 10, 1165-1169. Hughes, R.
P.; Lindner, D. C.; Smith, J . M.; Zhang, D.; Incarvito, C. D.; Lam, K.-
C.; Liable-Sands, L. M.; Sommer, R. D.; Rheingold, A. L. Dalton 2001,
2270-2278.
The reactions of 2a -c with XyNC or t-BuNC in a 1:2
molar ratio gave the compounds trans-[Rh(RF)(CNR′)2-
(PR3)] (RF ) CF3, R′ ) Xy, R ) Ph (4a ), C6H4OMe-4
(4b); RF ) CF3, R′ ) t-Bu, R ) Ph (4a ′); RF ) n-C3F7, R′
) Xy, R ) Ph (4c)), which were the result of the
substitution of the COD ligand by two XyNC ligands
(Scheme 2). Complexes 4a ,a ′,c were isolated in good
yields and spectroscopically and analytically character-
(19) Clark, H. C.; Reimer, K. J . Can. J . Chem. 1976, 54, 2077-2084.
Dart, J . W.; Lloyd, M. K.; Mason, R.; McCleverty, J . A. J . Chem. Soc.,
Dalton Trans. 1973, 2039-2045.
(20) Yagupsky, G.; Brown, C. K.; Wilkinson, G. Chem. Commun.
1969, 1244-1245.
(21) Nixon, J . F.; Swain, J . R. J . Organomet. Chem. 1974, 72, C15-
C17.

Rhodium(I) Perfluoroalkyl Complexes
Organometallics, Vol. 23, No. 21, 2004 4873
Sch em e 2
F igu r e 1. Molecular structure of 4a (50% thermal el-
lipsoids). Hydrogen atoms are omitted. Selected bond
lengths (Å) and angles (deg): Rh-C(1) ) 1.939(4), Rh-
C(2) ) 1.946(4), Rh-C(3) ) 2.076(3), Rh-P ) 2.3023(8),
N(1)-C(1) ) 1.164(4), N(2)-C(2) ) 1.152(4), C(3)-F(3) )
1.350(5), C(3)-F(2′) ) 1.365(6), C(3)-F(3′) ) 1.373(6),
C(3)-F(2) ) 1.391(6), C(3)-F(1) ) 1.396(6), C(3)-F(1′) )
1.413(6); F(2′)-C(3)-F(3′) ) 104.7(4), F(3)-C(3)-F(2) )
104.4(4), F(3)-C(3)-F(1) ) 104.0(3), F(2)-C(3)-F(1) )
98.7(3), F(2′)-C(3)-F(1′) ) 101.4(4), F(3′)-C(3)-F(1′) )
100.5(3), C(1)-Rh-C(2) ) 168.55(14), C(1)-Rh-C(3) )
ized. In addition, the structure of compound 4a was
established by a single-crystal X-ray diffraction study
(Figure 1). Owing to the elevated oxygen sensitivity of
complex 4b, it could be characterized only by NMR
spectroscopy. Thus, despite the the fact that the NMR
spectra of the reaction mixture showed that the reaction
of 2b with XyNC to give 4b is nearly quantitative, the
isolated solid after concentrating and adding n-pentane
always contained considerable amounts of tris(4-meth-
oxyphenyl)phosphine oxide and the peroxo complex [Rh-
(CF3)(η2-O2)(CNXy)2{P(C6H4OMe-4)3}] (7b), both impu-
rities arising from the reaction of 4b with residual
oxygen during its isolation. Complex 7b and the analo-
gous triphenylphosphine-containing complex 7a were
isolated by exposing THF solutions of 4b and 4a ,
respectively, to air and were characterized by spectro-
scopical and analytical means. A single-crystal X-ray
diffraction analysis of complex 7a (see Figure 2) revealed
unambiguously the presence of the peroxo ligand. The
formation of this complex seems to be irreversible,22
because it did not appreciably lose O2 in CDCl3 solution
under vacuum to regenerate compound 4a .
87.43(14), C(2)-Rh-C(3) ) 88.42(14), C(1)-Rh-P
)
95.25(10), C(2)-Rh-P ) 90.37(10), C(3)-Rh-P ) 171.59-
(10), N(1)-C(1)-Rh ) 173.8(3), N(2)-C(2)-Rh ) 173.9(3),
F(3)-C(3)-Rh ) 117.3(3), F(2′)-C(3)-Rh ) 116.8(3),
F(3′)-C(3)-Rh ) 117.8(3), F(2)-C(3)-Rh ) 113.2(3), F(1)-
C(3)-Rh ) 117.0(3), F(1′)-C(3)-Rh ) 113.2(3).
reactions were observed on treatment of 8a with 1 equiv
of XyNC or when complex 2a was treated with 4 equiv
of XyNC.
In the reaction of complex 2a with 3 equiv of t-BuNC,
1
the room-temperature H, 19F, and 31P{1H} NMR spec-
tra were consistent with the formation of [Rh(CF3)(CN-
t-Bu)3(PPh3)] (see Experimental Section). Unfortunately,
the attempts to isolate this complex gave an oily impure
material that could not be characterized, because its 19F
and 31P{1H} spectra showed broad signals even at low
temperatures.
Clean formation of [Rh(CF3)(PPh3)(CO)3] (9) and COD
in the reaction of complex 2a with CO in C6D6 was
1
observed by H, 19F, and 31P NMR and IR spectroscopy
When compounds 2a -c were treated with XyNC
using a 3:1 molar ratio of isocyanide to starting complex,
complexes [Rh(RF)(CNXy)3(PR3)] (RF ) CF3, R ) Ph
(8a ), C6H4OMe-4 (8b); RF ) n-C3F7, R ) Ph (8c)) were
obtained. Formation of 8a was also observed by NMR
when a C6D6 solution of complex 4a was treated with 1
equiv of XyNC. Compounds 8a -c were isolated in good
yields and characterized by spectroscopical and analyti-
cal means and, in the case of 8a , also by a single-crystal
X-ray diffraction study (see Figure 3). No further
(Scheme 3). However, the attempts to isolate 9 led to
mixtures of products that could not be separated nor
identified. The presence of three equivalent CO ligands
in 9 was confirmed by the 13C, 19F, and 31P{1H} NMR
spectra of its 13CO-containing analogue 9* (see below).
Cr ysta llogr a p h ic Stu d ies. The crystal structures
of complexes 4a , 7a , and 8a have been solved by single-
crystal X-ray diffraction studies. The crystal structure
of 2a has been preliminarily reported.15 These are the
first crystal structure determinations carried out on
Rh(I) perfluororalkyl complexes.
(22) Vaska, L. Acc. Chem. Res. 1976, 9, 175-183.

4874 Organometallics, Vol. 23, No. 21, 2004
Vicente et al.
F igu r e 3. Molecular structure of 8a (50% thermal el-
lipsoids). Hydrogen atoms are omitted. Selected bond
lengths (Å) and angles (deg): P(1)-Rh ) 2.3310(6), Rh-
C(3) ) 1.965(2), Rh-C(2) ) 1.986(2), Rh-C(1) ) 1.995(2),
Rh-C(4) ) 2.051(2), F(1)-C(4) ) 1.378(3), F(2)-C(4) )
1.371(3), F(3)-C(4) ) 1.379(3), C(1)-N(1) ) 1.165(3), C(2)-
N(2) ) 1.166(3), C(3)-N(3) ) 1.169(3); F(2)-C(4)-F(1) )
102.8(2), F(2)-C(4)-F(3) ) 102.9(2), F(1)-C(4)-F(3) )
102.8(2), C(3)-Rh-C(2) ) 127.48(9), C(3)-Rh-C(1) )
120.38(9), C(2)-Rh-C(1) ) 111.55(9), C(3)-Rh-C(4) )
87.55(9), C(2)-Rh-C(4) ) 87.85(9), C(1)-Rh-C(4) ) 86.88-
(9), C(3)-Rh-P(1) ) 90.22(7), C(2)-Rh-P(1) ) 92.87(7),
C(1)-Rh-P(1) ) 94.96(6), C(4)-Rh-P(1) ) 177.62(7),
N(1)-C(1)-Rh ) 173.0(2), N(2)-C(2)-Rh ) 176.5(2),
N(3)-C(3)-Rh ) 177.8(2), F(2)-C(4)-Rh ) 116.1(2), F(1)-
C(4)-Rh ) 114.9(2), F(3)-C(4)-Rh ) 115.5(2).
Sch em e 3
F igu r e 2. Molecular structure of 7a (top) (50% thermal
ellipsoids, hydrogen atoms are omitted) and packing dia-
gram showing the O‚‚‚H-C interactions (bottom). Selected
bond lengths (Å) and angles (deg): Rh(1)-C(9) ) 1.961(3),
Rh(1)-C(19) ) 1.968(3), Rh(1)-O(2) ) 2.010(2), Rh(1)-
O(1) ) 2.015(2), Rh(1)-C(10) ) 2.051(3), Rh(1)-P(1) )
2.3920(7), F(1)-C(10) ) 1.368(3), F(2)-C(10) ) 1.365(3),
F(3)-C(10) ) 1.357(3), N(1)-C(9) ) 1.158(4), N(2)-C(19)
) 1.152(4), O(1)-O(2) ) 1.438(3), C(18)‚‚‚O(2) ) 3.354(4),
C(17)‚‚‚O(2) ) 3.519(4), C(17)‚‚‚O(1) ) 3.649(4), C(23)‚‚‚
O(1) ) 3.263(4); F(3)-C(10)-F(2) ) 103.9(2), F(3)-C(10)-
F(1) ) 104.2(2), F(2)-C(10)-F(1) ) 103.6(2), C(9)-Rh(1)-
C(19) ) 90.86(11), C(9)-Rh(1)-C(10) ) 89.53(11), C(19)-
Rh(1)-C(10) ) 87.49(12), O(2)-Rh(1)-C(10) ) 87.88(10),
O(1)-Rh(1)-C(10) ) 91.13(10), C(9)-Rh(1)-P(1) ) 92.01(8),
C(19)-Rh(1)-P(1) ) 95.92(8), O(2)-Rh(1)-P(1) ) 89.30(6),
O(1)-Rh(1)-P(1) ) 85.10(6), C(10)-Rh(1)-P(1) ) 176.22-
(9), N(1)-C(9)-Rh(1) ) 177.2(2), F(3)-C(10)-Rh(1) )
114.37(19), F(2)-C(10)-Rh(1) ) 115.43(19), F(1)-C(10)-
Rh(1) ) 113.96(19), N(2)-C(19)-Rh(1) ) 177.1(3).
model,24,25 the F-C-F and Rh-C-F angles in the four
complexes are smaller (98.7-104.7°) and larger (113.2-
117.8°), respectively, than the ideal tetrahedral angle,
as has been observed for other perfluoroalkyl com-
plexes.17,26
In complex 4a , the metal is in a distorted-square-
planar environment (Figure 1), with C(1)-Rh-C(2)
(168.55(14)°) and C(3)-Rh-P (171.59(10)°) bond angles
appreciably lower than 180°. The CF3 group is disor-
dered between two positions, with a 50% probability for
each one. The Rh-CF3 and Rh-P bond distances
(2.076(3) and 2.3023(8) Å, respectively) are shorter than
those found in 2a (Rh-CF3, 2.097(2) and 2.112(2) Å;
Rh-P, 2.3245(5) and 2.3259(5) Å).15
Complex 7a has a distorted-octahedral geometry (see
Figure 2) in which the CF3 and PPh3 ligands are placed
trans to each other. The O-O (1.438(3) Å) and Rh-O
(2.010(2) and 2.015(2) Å) bond distances are typical
values for a Rh(III) peroxo complex.22,27-31 The Rh-
The mean C-F bond lengths are similar in the four
complexes (2a , 1.369(3) Å;15 4a , 1.381(6) Å; 7a , 1.363(3)
Å; 8a , 1.376(3) Å) and are slightly longer than the mean
C-F bond distances reported in compounds containing
trifluoromethyl groups bonded to nonmetallic atoms
(1.32223 and 1.33 Å24). In agreement with the VSEPR
(25) Purcell, K. F.; Kotz, J . C. Inorganic Chemistry; Holt-Saunders:
Philadelphia, PA, 1977.
(23) Allen, F. H.; Kennard, O.; Watson, D. G.; Brammer, L.; Orpen,
A. G.; Taylor, R. J . Chem. Soc., Perkin Trans. 2 1987, S1-S19.
(24) Yokozeki, A.; Bauer, S. H. Top. Curr. Chem. 1973, 53, 71-119.
(26) Hughes, R. P.; Smith, J . M.; Liable-Sands, L. M.; Concolino, T.
E.; Lam, K.-C.; Incarvito, C. D.; Rheingold, A. L. J . Chem. Soc., Dalton
Trans. 2000, 873-880.

Rhodium(I) Perfluoroalkyl Complexes
Organometallics, Vol. 23, No. 21, 2004 4875
Ta ble 1. Selected NMR Da ta of th e New Com p lexesa
δ(31P)
(ppm)
1J RhP
(Hz)
2J RhF
(Hz)
3J PF
(Hz)
compd
δ(19F) (ppm)
[Rh(CF3)(COD)(PPh3)] (2a )
[Rh(CF3)(COD)(P{C6H4OMe-4}3)] (2b)
[Rh(C3F7)(COD)(PPh3)] (2c)
-17.3 dd
-18.6 dd
33.3 dq
28.7 dq
31.2 dtt
26.7 dq
37.9 dq
33.2 dq
36.7 dq
31.7 dq
34.1 dt
36.2 dq
19.5 dq
15.8 dq
42.5 dq
38.3 dq
44.8 dt
31.7 dqq
177.9
175.7
175.7
159.1
161.4
186.3
102.3
102.2
103.7
146.1
68.3
19
20
21.4
20.8
38.5c
9.9
-86.9 m (F1), -116.4 br s (F2), -79.3 t (F3)b
[Rh(CF3)(COD)(Pi-Pr3)] (2d )
-17.8 dd
17.9
19.2
22.0
26.0
25.2
[Rh(CF3)(COD)(PCy3)] (2e)
-17.9 dd
10.6
13.4
46.2
45.9
20.3
45.5
68.9
70.0
60.1
61.4
37.8
60.9
[Rh(CF3)(NBD)(PPh3)] (3)d
-22.4 dd
trans-[Rh(CF3)(CNXy)2(PPh3)] (4a )d
trans-[Rh(CF3)(CNXy)2(P{C6H4OMe-4}3)] (4b)e
trans-[Rh(C3F7)(CNXy)2(PPh3)] (4c)
trans-[Rh(CF3)(CNt-Bu)2(PPh3)] (4a ′)
[Rh(CF3)(CNXy)2(η2-O2)(PPh3)] (7a )
[Rh(CF3)(CNXy)2(η2-O2)(P{C6H4OMe-4}3)] (7b)
[Rh(CF3)(CNXy)3(PPh3)] (8a )g
-5.7 dd
-5.1 dd
-82.3 br m (F1), -117.2 s (F2), -77.9 t (F3)f
-8.7 dd
27.4
10.4
10.7
8.1
-18.9 dd
-19.1 dd
71.1
76.5
76.1
75.9
3.1 dd
[Rh(CF3)(CNXy)3(P{C6H4OMe-4}3)] (8b)e
[Rh(C3F7)(CNXy)3(PPh3)] (8c)h
4.6 dd
7.5
-62.8 br m (F1), -112.6 s (F2), -76.9 s (F3)
8.2 ddq
[Rh(CF3)(13CO)3(PPh3)] (9*)i
68.9
8.0
a
Legend: s ) singlet, d ) doublet, t ) triplet, q ) quadruplet. The values correspond to room temperature unless the temperature is
given. 4J FF ) 11.1 Hz. 4J PF ) 4.6 Hz. T ) -20 °C. e T ) -60 °C. 4J FF ) 11.3 Hz. T ) -80 °C. T ) -84 °C. T ) -70 °C.
b
c
d
f
g
h
i
CNXy (1.961(3) and 1.968(3) Å) bond distances are
slightly longer than that found in [Rh(CN)(η2-O2)-
(CNXy)(PPh3)2]31 (1.935(4) Å), while the CtNXy bond
distances are close for both compounds (1.158(4) and
1.152(4) Å vs 1.159(5) Å). Short intermolecular C-
H‚‚‚O contacts were detected (i) between one oxygen
atom and methylic hydrogens of two neighboring mol-
ecules and (ii) between the other oxygen atom and C-H
groups of PPh3 and a methyl group of an adjacent
molecule. The C‚‚‚O distances are in the range 3.263-
3.649 Å. These contacts give rise to the formation of
layers of reciprocally interacting molecules.32 Hydrogen
bonding between a peroxo ligand and a N-H, O-H, or
C-H group in Rh(III) peroxo complexes has already
been reported.28,30,31 Whether the intermolecular con-
tacts observed for 7a originate from hydrogen bonding
or they are imposed by the packing of molecules cannot
be distinguished.
phosphine phenyl groups. Concerning the conformation
of the molecule, the CF3 and PPh3 groups are nearly
eclipsed with each other and alternated with respect to
the Rh(CNXy)3 unit. The C(2)-Rh-C(1) and C(3)-Rh-
C(2) (111.55(9) and 127.48(9)°, respectively) bond angles
are notably deviated from 120°. The Rh-CNXy bond
distances are longer for 8a (1.995(2), 1.986(2), and 1.965-
(2) Å) than for 4a (1.939(4) and 1.946(4) Å) and, as for
the CtN (1.165(3)-1.169(3) Å) bond distances, are
similar to the values found in other Rh(I) complexes
containing terminal isocyanide ligands.33
1
NMR a n d IR Sp ectr oscop y. The H NMR spectra
of the diene complexes 2a -e show two multiplets at
5.36-5.81 and 3.37-4.37 ppm corresponding to the
olefinic protons in positions trans to the phosphine34 and
CF3 ligands, respectively. The presence of only one
1
methyl resonance in the H NMR of complexes 4a -c,
4a ′, 7a ,b, and 8a -c is in agreement with the proposed
geometries (Scheme 2) and with those observed in the
crystal structures of 4a , 7a , and 8a .
Complex 8a has a trigonal-bipyramidal structure with
the XyNC ligands placed in the equatorial plane (Figure
3). The XyNC ligands are bent toward the CF3 ligand
(the C-Rh-CF3 angles are 87.55(9), 87.85(9), and 86.88-
(9)°), probably due to the steric repulsions with the
Especially useful for the characterization of the
complexes in solution were the 19F and 31P{1H} NMR
spectra (Table 1). The 19F NMR spectra of all trifluoro-
methyl complexes except 5 and 6a ,b gave doublets of
doublets by coupling with 103Rh and 31P, and the 31P-
{1H} NMR spectra gave doublets of quadruplets by
coupling with 103Rh and the three 19F atoms. In some
cases, the couplings were not observed at room temper-
ature due to ligand dissociation processes (see below),
but when the temperature was lowered, the expected
splitting patterns were observed in all cases. The 19F
NMR spectra of the n-heptafluoropropyl complexes 2c,
4c, and 8c gave three signals which were assigned by
means of a 19F,19F-COSY measurement for complex 8c
and by considering the usual order of magnitude of the
(27) Valentine, J . S. Chem. Rev. 1973, 73, 235-245.
(28) Bennet, M. J .; Donaldson, P. B. Inorg. Chem. 1977, 16, 1581-
1585. Takahashi, Y.; Hashimoto, M.; Hikichi, S.; Moro-ora, Y.; Akita,
M. Inorg. Chim. Acta 2004, 357, 1711-1724. Takahashi, Y.; Hash-
imoto, M.; Hikichi, S.; Akita, M.; Moro-ora, Y. Angew. Chem., Int. Ed.
Engl. 1999, 38, 3074-3077.
(29) Nolte, M. J .; Singleton, E. Acta Crystallogr., Sect. B 1975, 31,
2223-2227. Nolte, M. J .; Singleton, E. Acta Crystallogr., Sect. B 1976,
32, 1410-1413. Argouach, G.; Samuel, O.; Riant, O.; Daran, J . C.;
Kagan, H. B. Eur. J . Org. Chem. 2000, 2893-2899. Paneque, M.; Sirol,
S.; Trujillo, M.; Carmona, E.; Gutie´rrez-Puebla, E.; Monge, M. A.; Ruiz,
C.; Malbosc, F.; Serra-Le Berre, C.; Kalck, P.; Etienne, M.; Daran, J .
C. Chem. Eur. J . 2001, 7, 3868-3879. Nicasio, M. C.; Paneque, M.;
Pe´rez, P. J .; Pizzano, A.; Poveda, M. L.; Rey, L.; Sirol, S.; Taboada, S.;
Trujillo, M.; Monge, A.; Ruiz, C.; Carmona, E. Inorg. Chem. 2000, 39,
180-188. Osakada, K.; Hataya, K.; Yamamoto, T. Inorg. Chem. 1993,
32, 2360-2365. McGinnety, J . A.; Payne, N. C.; Ibers, J . A. J . Am.
Chem. Soc. 1969, 91, 6301-6310. Vigalok, A.; Shimon, L. J . W.;
Milstein, D. Chem. Commun. 1996, 1673-1674. Lindner, E.; Wang,
Q.; Mayer, H. A.; Fawzi, R.; Steinmann, M. J . Organomet. Chem. 1993,
453, 289-293.
(33) J ones, W. D.; Hessell, E. T. Organometallics 1990, 9, 718-727.
Yamamoto, Y.; Yamazaki, H. Inorg. Chim. Acta 1984, 85, 83-87.
Matubayashi, G.-E.; Tanaka, H.; Tanaka, T.; Nakatsu, K. Inorg. Chim.
Acta 1982, 63, 217-224. Hay-Motherwell, R. S.; Koschmieder, S. U.;
Wilkinson, G.; Hussain-Bates, B.; Hursthouse, M. B. J . Chem. Soc.,
Dalton Trans. 1991, 2821-2830. Yamamoto, Y.; Katsuyuki, A.;
Yamazaki, H. Inorg. Chem. 1979, 18, 1681-1687. Werner, H.; Schwab,
P.; Heinemann, A.; Steinert, P. J . Organomet. Chem. 1995, 496, 207-
216.
(34) Crabtree, R. H.; Gautier, A.; Giordano, G.; Khan, T. J . Orga-
nomet. Chem. 1977, 141, 113-121. Lahoz, F. J .; Martin, E.; Tiburcio,
J .; Torrens, H.; Terreros, P. Transition Met. Chem. 1994, 19, 381-
383.
(30) Ghilardi, C. A.; Midolini, S.; Moneti, S.; Orlandini, A.; Scapacci,
G. J . Chem. Soc., Dalton Trans. 1992, 3371-3376. Bianchini, C.;
Mealli, C.; Meli, A.; Proserpio, D. M.; Peruzzini, M.; Vizza, F. J .
Organomet. Chem. 1989, 369, C6-C10.
(31) Cˆırcu, V.; Fernandes, M. A.; Carlton, L. Polyhedron 2002, 21,
1775-1778.
(32) A drawing of the layer structure is given as Supporting
Information.

4876 Organometallics, Vol. 23, No. 21, 2004
Vicente et al.
F-F coupling constants in n-perfluoropropyl groups:
3J FF < 4J FF 35 Thus, the triplets observed from -78.1 to
.
-79.3 ppm were assigned to the CF3 fluorines, which
are coupled with the R-CF2 groups (4J FF ) 11.1-11.3
Hz), the multiplets observed from -81.8 to -86.9 ppm
were assigned to the R-CF2 groups, and the broad
singlets appearing from -112.6 to -117.2 ppm were
assigned to the â-CF2 groups. The room-temperature
31P{1H} NMR spectra gave a doublet of triplets of
triplets for 2c, due to coupling with 103Rh and the R-
and â-CF2 fluorine nuclei, a doublet of triplets for 4c,
due to coupling with 103Rh and the R-CF2 groups, and a
broad singlet for 8c, which was transformed into a
doublet of triplets at -84 °C.
The structures of complexes 5 and 6a ,b were proposed
on the basis of the 19F NMR spectra in the reaction
mixtures. Compounds 6a ,b gave doublets of triplets,36
which implies the presence of two equivalent phosphine
ligands, and 5 gave a doublet,37 which suggests the
2
absence of the phosphine ligand. The value of J RhF
,
which is similar to that found for 2a ,b, suggests the
presence of the COD ligand in a position trans to the
CF3 group.
All complexes containing isocyanide ligands gave
intense IR bands in the range 2028-2177 cm-1 corre-
sponding to the ν(CtN) vibrational mode. The carbonyl
complex 9 gave the ν(CO) band at 2012 cm-1. The O-O
stretching bands of peroxo complexes 7a ,b appear at 882
and 881 cm-1, respectively, which fall in the range
reported for Rh(III) peroxo complexes (833-893
cm-1).22,27,28,38 In the IR spectra of all isolated complexes,
several intense bands were observed in the region where
the C-F stretching modes of transition-metal perfluo-
roalkyl complexes usually appear (900-1350 cm-1).19,39
However, the unambiguous assignment of these bands
was complicated by the presence of absorptions in the
same region belonging to other ligands. For the triflu-
oromethyl complex 2a , several bands in the region 914-
1059 cm-1, which are typical of metal-bound CF3
groups,14,16,19,40 were assigned to ν(C-F) modes by
comparison with the IR spectrum of the related fluoro
complex 1a . The lowering of the C-F stretching wave-
numbers for transition-metal trifluoromethyl complexes
with respect to the values found in CF3X, where X )
Cl, Br, I (1058-1104 and 1117-1217 cm-1 for the A1
and E modes, respectively), has been taken as an
F igu r e 4. Variable-temperature 19F NMR (A) and 31P{1H}
NMR (B) spectra of 4a in d8-toluene measured at (from top
to bottom) 82, 23, -20, and -60 °C.
indication of the weakening of the C-F bond.6,41 The
perfluoropropyl complex 2c showed several bands in the
same region as for 2a which are assignable to the R-CF2
ν(C-F) modes, along with bands at higher wavenum-
bers (1143-1325 cm-1), which can be assigned to the
CF2CF3 group.42
Va r ia ble-Tem p er a tu r e NMR Stu d ies. The 19F and
31P{1H} NMR spectra of complexes 3, 4a ,b , 8, and 9
show at low temperatures the expected doublet of
doublets and doublet of quadruplets, respectively. At
room and higher temperatures, they show singlets or
broad doublets, suggesting that dynamic processes
involving phosphine dissociation take place. In addition,
the 19F NMR spectra of 4a and 8b show additional small
peaks (Figures 4 and 5). For 4a (-60 °C) they appear
as a doublet at -8.8 ppm (2J RhF ) 26.0 Hz), which we
assign to [Rh(CF3)(CNXy)3] (10), and a poorly resolved
multiplet at -9.2 ppm, assigned to complex 6a on the
basis of its chemical shift value (Scheme 4). Both signals
collapse at higher temperatures into a broad singlet,
indicating that the ligand exchange rates of the pro-
cesses shown in Scheme 4 are fast enough to average
these signals, which are close in frequency, but not fast
enough to average also the signal of 4a , which is far
away in the spectrum. Complex 4b shows a similar
behavior. In contrast, complexes 4c and 4a ′ show sharp
(35) Schorn, C.; Naumann, D.; Scherer, H.; Hahn, J . J . Fluorine
Chem. 2001, 107, 159-169. Foris, A. Magn. Reson. Chem. 2004, 42,
534-555.
(36) NMR data of 6a and 6b (C6D6). 6a : 19F NMR δ -10.4 (dt, 2J RhF
) 17.9 Hz, 3J PF ) 22.0 Hz). 6b: 19F NMR δ -10.4 (dt, 2J RhF ) 17.9 Hz,
3J PF ) 22.0 Hz). The 31P{1H} NMR spectra could not be assigned due
to overlapping with signals of other components of the mixture.
2
(37) NMR data of 5 (C6D6): 19F NMR δ -17.6 (d, J RhF ) 22.2 Hz).
(38) Pettinari, C.; Marchetti, F.; Pettinari, R.; Pizzabiocca, A.;
Drozdov, A.; Troyanov, S. I.; Vertlib, V. J . Organomet. Chem. 2003,
688, 216-226. Pettinari, C.; Marchetti, F.; Cingolani, A.; Bianchini,
G.; Drozdov, A.; Vertlib, V.; Troyanov, S. J . Organomet. Chem. 2002,
651, 5-14. Hill, A. F.; White, A. J . P.; Williams, D. J .; Wilton-Ely, J .
D. E. T. Organometallics 1998, 17, 3152-3154. Nakamura, A.; Tatsuno,
Y.; Otsuka, S. Inorg. Chem. 1972, 11, 2058-2064. Harris, R. O.; Powell,
J .; Walker, A.; Yaneff, P. V. J . Organomet. Chem. 1977, 141, 217-
229.
(39) Rosevear, D. T.; Stone, F. G. A. J . Chem. Soc. A 1968, 164-
167. Burrell, A. K.; Clark, G. R.; Rickard, C. E. F.; Roper, W. R. J .
Organomet. Chem. 1994, 482, 261-269.
(40) Greene, T. R.; Roper, W. R. J . Organomet. Chem. 1986, 299,
245-250. Clark, G. R.; Hoskins, S. V.; Roper, W. R. J . Organomet.
Chem. 1982, 234, C9-C12. Appleton, T. G.; Berry, R. D.; Hall, J . R.;
Neale, D. W. J . Organomet. Chem. 1989, 364, 249-273.
(41) Cotton, F. A.; Wing, R. M. J . Organomet. Chem. 1967, 9, 511-
517. Cotton, F. A.; McCleverty, J . A. J . Organomet. Chem. 1965, 4,
490.
(42) Richmond, T. G.; Shriver, D. F. Organometallics 1984, 3, 305-
314.

Rhodium(I) Perfluoroalkyl Complexes
Organometallics, Vol. 23, No. 21, 2004 4877
Sch em e 5
and, in the 31P{1H} NMR spectrum, a broad singlet
which is converted into the expected doublet of triplets
at low temperature. A shift to higher field of the 31P
NMR signal from low to high temperature is also
observed, suggesting the temperature dependence of the
PPh3 dissociation as in 8a ,b.
The 19F and 31P{1H} NMR spectra of compound 9
show a broad doublet and a doublet of quadruplets,
1
3
respectively, with J RhP ) 69.3 Hz and J PF ) 62.0 Hz,
which is in agreement with the presence of the CF3 and
PPh3 groups bonded to Rh, but did not allow us to
determine the number of CO ligands or the structure
of the complex. However, the coupling patterns of the
19F and 31P{1H} NMR spectra of the 13CO-containing
analogue 9* at -70 °C (a doublet of doublets of qua-
druplets and a doublet of quadruplets of quadruplets,
respectively) and the values of coupling constants (3J PF
) 60.8 Hz, 3J CF ) 10.3 Hz, 2J RhF ) 8.0 Hz, 1J RhP ) 68.9
F igu r e 5. Variable-temperature 19F NMR (A) and 31P{1H}
NMR (B) spectra of 8b in d8-toluene measured at (from
top to bottom) 77, 58, 23, and -60 °C. The peak around 25
ppm in the 31P spectra corresponds to OP(C6H4OMe-4)3.
2
Hz, J PC ) 15.4 Hz), similar to those found in the
pentacoordinate complexes 8a and 8b, were in full
agreement with the presence of three equivalent 13CO
ligands in a trigonal-bipyramidal structure. Because the
room-temperature 19F and 31P{1H} NMR spectra of 9*
are similar to those of 9 (i.e., couplings of 13CO with
103Rh, 19F, and 31P are not observed), fast 13CO dissocia-
tion on the NMR time scale takes place in solution, as
does that of isocyanide in 8a ,b. However, since the 31P-
103Rh and 31P-19F couplings in 9* were observed at all
temperatures, dissociation of the PPh3 does not occur
noticeably.
Sch em e 4
Con clu sion s
signals with the expected coupling patterns at room
temperature. We do not have an explanation for this
difference.
We report the synthesis of the perfluoroalkyl com-
plexes [Rh(RF)(COD)(PR3)] prepared by reacting the
corresponding fluoro complexes with (perfluoroalkyl)-
trimethylsilanes. This work represents the first applica-
tion of this synthetic method to the chemistry of Rh(I).
We have also studied the reactivity of some of these
perfluoroalkyl complexes toward norbornadiene, isocya-
nides, and carbon monoxide. Depending on the molar
ratio of complex to isocyanide used, tetra- or pentaco-
ordinated complexes containing diolefin, isocyanide, or/
and triarylphosphine ligands, in addition of the RF
group, have been isolated or detected in solution. The
reaction of [Rh(CF3)(COD)(PPh3)] with CO gives the
tricarbonyl complex [Rh(CF3)(PPh3)(CO)3]. All of the
above compounds form the first family of rhodium(I)
perfluoroalkyl complexes reported so far. trans-[Rh-
(CF3)(CNXy)2(PR3)] are very reactive species, giving the
rhodium(III) peroxo complexes [Rh(CF3)(η2-O2)(CNXy)2-
For 8b, the small signals appear (-60 °C) as a doublet
at -8.7 ppm (2J RhF ) 24.5 Hz) that we assigned to 10,
as we did in the low-temperature 19F NMR spectrum of
4a , and a doublet of doublets at -4.9 ppm (3J PF ) 46.0
2
Hz, J RhF ) 25.7 Hz), corresponding to 4b, indicating
that not only phosphine but also isocyanide dissociation
takes place (Scheme 5). In addition, both 19F and 31P-
{1H} signals of 8a shift at higher temperatures toward
the signal of 10 and that of the free phosphine (-9.5
ppm for P(C6H4OMe-4)3 in C6D6), respectively, suggest-
ing that the phosphine dissociation degree becomes
higher when the temperature increases. A similar
behavior is shown by 8a . The heptafluoropropyl complex
8c shows in its room-temperature 19F NMR spectrum
a broad multiplet for the R-fluorine nuclei, which is not
resolved in the temperature range from +80 to -84 °C,

4878 Organometallics, Vol. 23, No. 21, 2004
Vicente et al.
3
2
1J RhC ) 7.0 Hz, J FC ) 1.7 Hz), 30.8 (d, CH2, J RhC ) 1.7 Hz),
(PR3)] when in contact with O2. Fast phosphine, isocya-
nide, or CO ligand dissociation and exchange processes
in solution have been observed by variable-temperature
NMR in most of the reported complexes. We also
describe the first crystal structure determinations car-
ried out on Rh(I) perfluororalkyl complexes. Current
work in our laboratories is aimed at more studies on
the reactivity of these and other rhodium perfluoroalkyl
complexes. Given the growing number of transition-
metal fluoro derivatives which are being described in
the literature, and the lack of general synthetic methods
for the synthesis of perfluoroalkyl derivatives of transi-
tion metals in low oxidation states, the reported syn-
thetic approach is promising for the preparation of these
complexes, including those with RF * CF3. These
perfluoroalkyl derivatives are promising substrates for
the development of new C-F activation and C-C bond
formation reactions.
30.8 (s, CH2).19F NMR (188.3 MHz, C6D6): δ -17.3 (t, J RhF
)
2
3J PF ) 19 Hz). 31P{1H} NMR (81.0 MHz, C6D6): δ 33.3 (dq,
1J RhP ) 177.9 Hz, J PF ) 21.4 Hz).
3
The presence of Me3SiF in the reaction mixture was
confirmed by NMR-tube reactions (C6D6). 1H NMR: δ 0.02 (d,
3J FH ) 6.9 Hz). 19F NMR: δ -157.6 (decaplet).12,43
[Rh (CF 3)(COD){P (C6H4OMe-4)3}] (2b). A solution of 1b
(76 mg, 0.13 mmol) in THF (5 mL) was treated with Me3SiCF3
(0.13 mL of a 2.0 M solution in THF, 0.26 mmol) and stirred
for 5 min at room temperature. Due to the oxygen and
moisture sensitivity of 2b, we were unable to isolate it in pure
form. Nevertheless, solutions of 2b obtained by this method
were used successfully in subsequent reactions. 1H NMR (200.1
MHz, C6D6): δ 7.54 (m, 6 H, H2, C6H4), 6.88 (m, 6 H, H3, C6H4),
5.36 (m, 2 H, CH, COD), 3.78 (s, 9 H, OMe), 3.76 (m, 2 H, CH,
COD), 2.34, 2.18, 2.02 (3 m, 8 H, CH2). 13C{1H} NMR (100.8
2
MHz, CD2Cl2): δ 161.4 (s, C4, C6H4), 136.2 (d, C2, C6H4, J PC
1
) 13.6 Hz), 125.3 (d, C1, C6H4, J PC ) 44.4 Hz), 113.9 (d, C3,
3
1
2
C6H4, J PC ) 11.1 Hz), 96.9 (t, CH, COD, J RhC ) J PC ) 9.2
1
Hz), 89.0 (d, CH, COD, J RhC ) 7.4 Hz), 55.7 (s, OMe), 31.0,
30.9 (2s, CH2); the signal of the CF3 carbon was not observed.
Exp er im en ta l Section
19F NMR (188.3 MHz, C6D6): δ -18.6 (t, J RhF
)
3J PF ) 20
2
Hz). 31P{1H} NMR (81.0 MHz, C6D6): δ 28.7 (dq, 1J RhP ) 175.7
Gen er a l Con sid er a tion s. The preparation of compounds
1a ,b,d ,e was carried out as we described previously.1 Other
reagents were obtained from commercial sources and used
without further purification: Me3SiCF3, norbornadiene, XyNC,
and t-BuNC from Fluka and Me3SiC3F7 and 13CO (99% 13C)
from Aldrich.. All manipulations were carried out under an
inert atmosphere of nitrogen by using standard Schlenk
techniques. Tetrahydrofuran, toluene, and Et2O were distilled
over sodium-benzophenone, n-hexane was passed through a
basic alumina column and deoxygenated, and n-pentane was
distilled over CaH2. All solvents were stored under nitrogen
over 4 Å molecular sieves.
Infrared spectra were recorded in the range 4000-200 cm-1
on a Perkin-Elmer 16F PC FT-IR spectrometer with Nujol
mulls between polyethylene sheets. C, H, S analyses were
carried out with Carlo Erba 1108 and Perkin-Elmer 2400
microanalyzers. NMR spectra were measured on Bruker
Avance 200, 300, and 400 instruments. 1H chemical shifts were
referenced to residual C6D5H (7.15 ppm), C6D5-CD2H (2.09
ppm), CHDCl2 (5.29 ppm), or CHCl3 (7.26 ppm). 13C{1H} NMR
spectra were referenced to C6D6 (128.0 ppm), CDCl3 (77.1 ppm),
or external (CD3)2SO (40.4 ppm). 19F NMR spectra were
referenced to external CFCl3 (0 ppm). 31P{1H} NMR spectra
were referenced externally to H3PO4 (0 ppm). In cases where
19F and 31P{1H} NMR spectra were measured in nondeuterated
THF, a external CD3COCD3 capillary was used for locking and
referencing. The temperature values in NMR experiments
were not corrected. Melting points were determined on a
Reichert apparatus under an air atmosphere.
3
Hz, J PF ) 20.8 Hz).
[Rh (C3F 7)(COD)(P P h 3)] (2c). A solution of 1a (149 mg,
0.30 mmol) in THF (5 mL) was treated with Me3SiC3F7 (0.13
mL, 0.26 mmol) and stirred for 15 min at room temperature.
The resulting orange solution was concentrated under reduced
pressure to ca. 0.5 mL, and by addition of n-pentane (3 mL),
an orange solid precipitated. The solution was removed by
means of a pipet, and the solid was washed with n-pentane (3
× 1 mL) and dried under vacuum. Yield: 181 mg, 93.1%. Mp:
102 °C. Anal. Calcd for C29H27F7PRh: C, 54.22; H, 4.24.
Found: C, 53.97; H, 4.31. IR (CH2Cl2, cm-1): ν(C-F) 1325,
1219, 1184 (vs), 1143, 1071, 1009, 943 (s). 1H NMR (200.1 MHz,
C6D6): δ 7.82-7.72 (m, 6 H, Ph), 7.05-7.02 (m, 9 H, Ph), 5.73
(m, 2 H, CH, COD), 3.82 (m, 2 H, CH, COD), 2.20-1.60 (several
m, 8H, CH2). 13C{1H} NMR (75.4 MHz, C6D6): δ 134.9 (d, C2,
2
1
Ph, J PC ) 12.2 Hz), 134.0 (d, C1, Ph, J PC ) 38.6 Hz), 130.0
4
3
(d, C4, Ph, J PC ) 2.2 Hz), 128.2 (d, C3, Ph, J PC ) 9.4 Hz),
1
95.8 (m, CH, COD), 88.4 (d, CH, COD, J RhC ) 7.3 Hz), 30.9
2
(s, CH2), 30.5 (d, CH2, J RhC ) 1.7 Hz); the signals of the C3F7
carbons were not observed. 19F NMR (188.3 MHz, C6D6): δ
-79.3 (t, 3 F, CF3, 4J
) 11.1 Hz), -86.9 (m, 2 F, R-F), -116.4
FF
(br s, 2 F, â-F). 31P{1H} NMR (81.0 MHz, C6D6): δ 31.2 (dtt,
1J RhP ) 175.7 Hz, J PF ) 38.5 Hz, J PF ) 4.6 Hz).
3
4
[Rh (CF 3)(NBD)(P P h 3)] (3). A solution of 1a (134 mg, 0.27
mmol) in THF (3 mL) was treated with Me3SiCF3 (0.27 mL of
a 2.0 M solution in THF, 0.54 mmol) and stirred for 5 min at
room temperature. The volatiles were removed in vacuo, and
Et2O (10 mL) and norbornadiene were added (0.22 mL, 2.22
mmol) to give, after 1 h of stirring, a red solution containing
a small amount of a fine solid in suspension. The suspension
was concentrated under reduced pressure to ca. 0.5 mL, and
addition of n-pentane (5 mL) gave a precipitate of an orange
solid. The solution was removed by means of a pipet, and the
solid was washed with n-pentane (4 × 5 mL) and dried under
vacuum. Yield: 121 mg, 84.5%. Mp: 128 °C dec. Anal. Calcd
for C26H23F3PRh: 59.33; H, 4.40. Found: C, 58.98; H, 4.21.
1H NMR (200.1 MHz, C6D6): δ 7.64 (m, 6 H, H2, PPh3), 7.01
(s, 9 H, H3 and H4, PPh3), 5.51 (m, 2 H, CHdCH, NBD), 3.72
(m, 2 H, CH, NBD), 3.37 (m, 2 H, CHdCH, NBD), 1.17, 1.00
[Rh (CF 3)(COD)(P P h 3)] (2a ). A solution of 1a (180 mg, 0.37
mmol) in THF (12 mL) was treated with Me3SiCF3 (0.20 mL
of a 2.0 M solution in THF, 0.40 mmol) and stirred for 10 min
at room temperature. The resulting orange solution was
concentrated under reduced pressure to ca. 1 mL. On addition
of n-hexane (5 mL), an orange solid precipitated. The solution
was removed by means of a pipet, and the solid was washed
with n-hexane (2 × 5 mL) and dried under vacuum. Yield: 152
mg, 76%. Mp: 124-128 °C dec. Anal. Calcd for C27H27F3PRh:
C, 59.79; H, 5.02. Found: C, 59.42; H, 5.00. IR (Nujol, cm-1):
ν(C-F) 1059 (vs), 948, 935, 928, 914 (s). IR (CH2Cl2, cm-1):
1
(AB system, 2 H, CH2, J HH ) 7.8 Hz). 13C{1H} NMR (50.3
2
1065, 963, 921. H NMR (200.1 MHz, C6D6): δ 7.84-7.74 (m,
2
6 H, Ph), 7.06-7.02 (m, 9 H, Ph), 5.81 (m, 2 H, CH, COD),
MHz, C6D6): δ 134.6 (d, C2, PPh3, J PC ) 12.8 Hz), 133.7 (d,
3.87 (m, 2 H, CH, COD), 2.16-1.73 (several m, 8 H, CH2). 13C-
1
C1, PPh3, J PC ) 39.1 Hz), 130.3 (s, C4, PPh3), 128.7 (d, C3,
1
{1H} NMR (75.4 MHz, C6D6): δ 143.7 (qdd, CF3, J RhC ) 62.7
3
PPh3, J PC ) 11.0 Hz), 81.6, 77.8 (2 br s, CdC, NBD), 68.0 (s,
2
1
2
Hz, J PC ) 8.7 Hz, J FC ) 366.4 Hz), 134.9 (d, C2, Ph, J PC
)
1
12.8 Hz), 134.1 (d, C1, Ph, J PC ) 39.0 Hz), 130.1 (d, C4, Ph,
(43) Bassindale, A. R.; Baukov, Y. I.; Borbaruah, M.; Glynn, S. J .;
Negrebetsky, V. V.; Parker, D. J .; Taylor, P. G.; Turtle, R. J .
Organomet. Chem. 2003, 669, 154-163.
4J PC ) 1.7 Hz), 128.3 (d, C3, Ph, J PC ) 9.8 Hz), 97.4 (tq, CH,
3
COD, 1J RhC ) 2J PC ) 9 Hz, 3J FC ) 2.3 Hz), 88.9 (dq, CH, COD,

Rhodium(I) Perfluoroalkyl Complexes
Organometallics, Vol. 23, No. 21, 2004 4879
CH2), 53.0 (s, CH, NBD); the signal of the CF3 carbon was not
observed. 19F NMR (188.3 MHz, C6D6, 22 °C): δ -22.7 (br d,
2J RhF ) 21.3 Hz). 19F NMR (188.3 MHz, d8-toluene, -20 °C):
134.9 (s, C2, Xy), 127.9 (d, C1, C6H4, 1J PC ) 41.3 Hz), 127.7 (s,
C4, Xy), 127.5 (s, C3, Xy), 113.5 (d, C3, C6H4, J PC ) 9.9 Hz),
3
54.6 (s, OMe), 17.7 (s, Me); the signals corresponding to the
CF3 and Xy group C1 carbons were not observed. 19F NMR
(188.3 MHz): C6D6, 22 °C, δ -5.6 (br s); d8-toluene, -60 °C, δ
-5.1 (dd, 3J PF ) 45.9 Hz, 2J RhF ) 25.2 Hz). 31P{1H} NMR (81.0
MHz): C6D6, 22 °C, δ 30.7 (br s); d8-toluene, -60 °C, δ 31.7
2
3
δ -22.4 (dd, J RhF ) 22.0 Hz, J PF ) 13.4 Hz). 31P{1H} NMR
1
(81.0 MHz, C6D6, 22 °C): δ 32.8 (br d, J RhP ) 182.6 Hz). 31P-
1
{1H} NMR (81.0 MHz, d8-toluene, -20 °C): δ 33.2 (dq, J RhP
3
) 186.3 Hz, J PF ) 13.1 Hz).
1
3
(dq, J RhP ) 102.2 Hz, J PF ) 46.1 Hz).
tr a n s-[Rh (CF 3)(CNXy)2(P P h 3)] (4a ). A solution of 2a ,
obtained from 1a (168 mg, 0.34 mmol), THF (7 mL), and Me3-
SiCF3 (0.30 mL of a 2.0 M solution in THF, 0.60 mmol), was
treated with XyNC (89 mg, 0.68 mmol) at room temperature
and stirred for 1 h. The resulting yellow-orange solution was
concentrated under reduced pressure (ca. 0.5 mL), and Et2O
(5 mL) was added to give a yellow-orange precipitate. The
solution was removed by means of a pipet, and the solid was
washed with Et2O (3 × 2 mL) and dried under vacuum. Yield:
156 mg, 65.6%. Mp: 116-118 °C dec. Anal. Calcd for
tr a n s-[Rh (C3F 7)(CNXy)2(P P h 3)] (4c). A solution of 2c,
prepared from 1a (152 mg, 0.31 mmol) and Me3SiC3F7 (0.13
mL, 0.62 mmol) in THF (6 mL), was treated with XyNC (81
mg, 0.62 mmol) at room temperature and stirred for 1 h. The
resulting yellow solution was concentrated under reduced
pressure to 0.5 mL; addition of Et2O (2 mL) gave a suspension
containing a yellow solid. The solution was removed by means
of a pipet, and the solid was washed with Et2O (3 × 1 mL)
and dried under vacuum. Yield: 137 mg, 55.7%. Mp: 97 °C
dec. Anal. Calcd for C39H33N2F7PRh: C, 58.81; H, 4.18; N, 3.52.
Found: C, 58.52; H, 3.96; N, 3.52. IR (cm-1): ν(CtN) 2097
C
37H33N2F3PRh: C, 63.80; H, 4.78; N, 4.02. Found: C, 63.76;
H, 4.51; N, 4.05. IR (cm-1): ν(CtN) 2087 (vs). 1H NMR (400.9
MHz, CD2Cl2): δ 7.64 (m, 6 H, H2, Ph3P), 7.28 (m, 9 H, H3
and H4, Ph3P), 7.00 (AB2 m, 6 H, Xy), 1.95 (s, 12 H, Me). 13C-
{1H} NMR (100.8 MHz, THF/d6-DMSO (ext)): δ 162.5 (br d,
CtN, 1J RhC ) 59.7 Hz), 136.4 (d, C1, Ph, 1J PC ) 37.3 Hz), 135.3
1
(vs). H NMR (300.1 MHz, C6D6): δ 7.82 (m, 6 H, H2, Ph3P),
6.87 (m, 9 H, H3 + H4, Ph3P), 6.57 (AB2 m, 6 H, CH, Xy), 1.89
(s, 12 H, Me). 13C{1H} NMR (100.8 MHz, C6D6): δ 162.6 (br d,
1
1
CtN, J RhC ) 65.6 Hz), 137.5 (d, C1, PPh3, J PC ) 37.6 Hz),
2
(s, C2, Xy), 134.8 (d, C2, Ph, J PC ) 13.1 Hz), 129.9 (s, C4,
2
135.7 (s, C2, Xy), 135.3 (d, C2, PPh3, J PC ) 12.5 Hz), 130.3
3
Ph), 128.4 (d, C3, Ph, J PC ) 9.9 Hz), 128.0 (s, C4, Xy), 127.8
4
3
(d, C4, PPh3, J PC ) 1.5 Hz), 128.9 (d, C3, PPh3, J PC ) 8.8
Hz), 128.2 (s, C3, Xy), 18.9 (s, Me). The signals of the C3F7
carbons and C1 and C4 of Xy were not observed. 19F NMR
(282.4 MHz, C6D6): δ -77.9 (t, 3 F, CF3, 4J FF ) 11.3 Hz), -82.3
(br m, 2 F, R-F), -117.2 (s, 2 F, â-F). 31P{1H} NMR (121.5 MHz,
(s, C3, Xy), 17.1 (s, Me); the signals corresponding to the CF3
and Xy C1 carbons were not observed. 19F NMR (188.3 MHz,
d8-toluene): 23 °C, δ -6.1 (br d, 2J RhF ) 24 Hz); -20 °C, δ -5.7
3
2
(dd, J PF ) 45.9 Hz, J RhF ) 26.0 Hz). 31P{1H} NMR (162.3
MHz, d8-toluene): 23 °C, δ 36.6 (br s); -20 °C, δ 36.7 (dq, 1J RhP
) 102.3 Hz, J PF ) 46.2 Hz).
1
3
C6D6): δ 34.1 (dt, J RhP ) 103.7 Hz, J PF ) 20.3 Hz).
3
tr a n s-[Rh (CF 3)(η2-O2)(CNXy)2(P P h 3)] (7a ). A solution of
2a , prepared from 1a (129 mg, 0.26 mmol) and Me3SiCF3 (0.26
mL of a 2.0 M solution in THF, 0.52 mmol) in THF (5 mL),
was treated with XyNC (68 mg, 0.52 mmol) at room temper-
ature and stirred for 1 h. The volatiles were removed in vacuo,
the resulting residue was redissolved in THF (5 mL), and air
was bubbled through the solution for 30 min. A colorless solid
precipitated, which was filtered, washed with Et2O (4 × 10
mL), and dried under vacuum. Yield: 104 mg, 54.5%. Mp: 110
°C. Anal. Calcd for C37H33N2O2F3PRh: C, 60.95; H, 4.57; N,
3.62. Found: C, 61.00; H, 4.57; N, 3.85. IR (cm-1): ν(CtN)
2170 (s), 2145 (s), ν(O-O) 882 (s). 1H NMR (300.1 MHz,
CDCl3): δ 7.54 (m, 6 H, H2, Ph3P), 7.34 (m, 9 H, H3 + H4,
Ph3P), 7.14 (AB2 m, 6 H, CH, Xy), 2.06 (s, 12 H, Me). 13C{1H}
tr a n s-[Rh (CF 3)(CN-t-Bu )2(P P h 3)] (4a ′). A solution of 2a ,
prepared from 1a (161 mg, 0.33 mmol) and Me3SiCF3 (0.33
mL of a 2.0 M solution in THF, 0.66 mmol) in THF (5 mL),
was treated with t-BuNC (74 µL, 0.68 mmol) at room temper-
ature and stirred for 1 h. The resulting yellow-orange solution
was concentrated under reduced pressure (ca. 0.5 mL), and
an oil precipitated, which was converted into a yellow solid
upon stirring for 30 min at 0 °C. The solution was removed by
means of a pipet, and the solid was washed with n-pentane (2
× 5 mL) and dried under vacuum. Yield: 176 mg, 96.8%. Mp:
92 °C. Anal. Calcd for C29H33N2F3PRh: C, 58.01; H, 5.54; N,
4.67. Found: C, 57.74; H, 5.21; N, 4.56. IR (cm-1): ν(CtN)
2123 (vs). 1H NMR (300.1 MHz, C6D6): δ 7.78 (m, 6 H, H2,
Ph3P), 7.03 (m, 9 H, H3 + H4, Ph3P), 0.74 (s, 18 H, t-Bu). 13C-
1
NMR (75.5 MHz, CDCl3): δ 150.3 (br d, CtN, J RhC ) 60.6
1
{1H} NMR (75.5 MHz, C6D6): δ 150.1 (d, CtN, J RhC ) 49.2
2
Hz), 136.0 (s, C2, Xy), 134.7 (d, C2, PPh3, J PC ) 11.0 Hz),
1
Hz), 138.2 (d, C1, PPh3, J PC ) 35.4 Hz), 135.4 (d, C2, PPh3,
1
131.2 (d, C1, PPh3, J PC ) 43.1 Hz), 130.9 (s, C4, PPh3), 129.6
3
2J PC ) 12.2 Hz), 130.0 (s, C4, PPh3), 128.4 (d, C3, PPh3, J PC
3
(s, C4, Xy), 128.8 (d, C3, PPh3, J PC ) 9.4 Hz), 128.3 (s, C3,
) 5.0 Hz), 56.4 (s, CMe3), 30.2 (s, Me). 19F NMR (282.4 MHz,
Xy), 127.4 (s, C1, Xy) 18.5 (s, Me); the signal of the CF3 carbon
2
3
C6D6): δ -8.7 (dd, J RhF ) 27.4 Hz, J PF ) 39.5 Hz). 31P{1H}
was not observed. 19F NMR (282.4 MHz, CDCl3): δ -18.9 (dd,
1
3
NMR (121.5 MHz, C6D6): δ 36.2 (dq, J RhP ) 146.1 Hz, J PF
)
3
2J RhF ) 10.4 Hz, J PF ) 68.9 Hz). 31P{1H} NMR (121.5 MHz,
45.5 Hz).
1
3
CDCl3): δ 19.5 (quintuplet, J RhP ) J PF ) 68.3 Hz).
tr a n s-[Rh (CF 3)(CNXy)2{P (C6H4OMe-4)3}] (4b). A solu-
tion of 2b, prepared from 1b (190 mg, 0.33 mmol) and Me3-
SiCF3 (0.33 mL of a 2.0 M solution in THF, 0.66 mmol) in THF
(4 mL), was treated with XyNC (85 mg, 0.65 mmol) at room
temperature and stirred for 1 h. The orange solution was
concentrated under reduced pressure (ca. 0.5 mL), and n-
pentane (10 mL) was added. An oil precipitated, which was
converted into a yellow-orange solid upon stirring for 1 h at 0
°C. The solution was removed by means of a pipet, and the
solid was washed with n-pentane (3 × 5 mL) and dried under
vacuum. The isolated solid was a mixture of 4b, 7b, and OP-
(C6H4OMe-4)3, which could not be separated. The ratio between
the two first species, determined by integration of the 19F NMR
spectrum, was aproximately 8:1. Data for 4b are as follows.
1H NMR (200.1 MHz, C6D6): δ 7.83 (m, 6 H, H2, C6H4), 6.60
(m, 12 H, H3, C6H4 + CH, Xy), 3.14 (s, 9 H, OMe), 2.04 (s, 12
H, Me, Xy). 13C{1H} NMR (100.8 MHz, THF/d6-DMSO (ext)):
δ 162.4 (br d, CtN, 1J RhC ≈ 70 Hz, overlapped with an impurity
peak), 161.1 (s, C4, C6H4), 135.6 (d, C2, C6H4, 2J PC ) 14.2 Hz),
tr a n s-[Rh (CF3)(η2-O2)(CNXy)2{P (C6H4OMe-4)3}] (7b). This
compound was prepared as for 7a from 1b (109 mg, 0.19
mmol), Me3SiCF3 (0.20 mL of a 2.0 M solution in THF, 0.40
mmol) in THF (4 mL), and XyNC (49 mg, 0.38 mmol). Yield:
85 mg, 55.5%. Mp: 116 °C. Anal. Calcd for C40H39N2O5F3-
PRh: C, 58.69; H, 4.80; N, 3.42. Found: C, 58.43; H, 4.77; N,
3.23. IR (cm-1): ν(CtN) 2177 (s), 2151 (vs), ν(O-O) 881 (m).
1H NMR (300.1 MHz, CDCl3): δ 7.45 (m, 6 H, H2, C6H4), 7.14
3
(t, J HH ) 7.5 Hz, 2 H, H4, Xy), 7.02 (d, 4 H, H3, Xy), 6.83 (m,
6 H, H3, C6H4), 3.76 (s, 9 H, OMe, Xy), 2.09 (s, 12 H, Me, Xy).
4
13C{1H} NMR (100.8 MHz, CDCl3): δ 161.7 (d, C4, C6H4, J PC
1
) 2.2 Hz), 150.9 (br d, CtN, J RhC ) 54.4 Hz), 136.1 (d, CH,
C6H4, J PC ) 12.5 Hz), 136.0 (s, C2, Xy), 129.5 (s, C4, Xy), 128.3
1
(s, C3, Xy), 127.5 (br s, C1, Xy), 122.9 (d, C1, C6H4, J PC
)
43.5 Hz3), 114.4 (d, J PC ) 11.1 Hz, CH, C6H4), 55.6 (s, OMe),
18.6 (s, Me). 19F NMR (282.4 MHz, CDCl3): δ -19.1 (dd, 2J RhF
3
) 10.7 Hz, J PF ) 70.0 Hz). 31P{1H} NMR (121.5 MHz,
1
3
CDCl3): δ 15.8 (quintuplet, J RhP ) J PF ) 71.1 Hz).

4880 Organometallics, Vol. 23, No. 21, 2004
Ta ble 2. Cr ysta l Da ta for Com p lexes 4a , 7a , a n d 8a
Vicente et al.
4a
7a
8a
formula
Mr
C
37H33F3N2PRh
C38H35Cl2F3N2O2PRh
813.46
C46H42F3N3PRh
827.71
696.53
cryst size (mm)
cryst syst
space group
cell constants
a (Å)
0.46 × 0.37 × 0.18
monoclinic
P21/n
0.19 × 0.16 × 0.10
0.60 × 0.52 × 0.37
monoclinic
triclinic
P21/c
P1h
15.9615(9)
11.1136(9)
19.4852(12)
90
112.700(4)
90
3188.7(4), 4
0.710 73
1.424
17.8190(8)
9.5009(5)
21.6317(10)
90
103.809(1)
90
3556.3(3), 4
0.710 73
1.519
11.4854(6)
12.1920(5)
15.3971(6)
107.118(3)
93.460(4)
101.193(4)
2005.4(2), 2
0.710 73
b (Å)
c (Å)
R (deg)
â (deg)
γ (deg)
V (Å3), Z
λ (Å)
F(calcd) (Mg m-3
F(000)
)
1.371
852
2404
1656
T (K)
173(2)
0.632
100(2)
0.728
173(2)
0.515
µ (mm-1
)
transmissn
θ range (deg)
limiting indices
0.843-0.821
3.14-25.00
-17 e h e 18
-13 e k e 4
-23 e l e 0
0.931-0.874
1.94-28.17
-22 e h e 22
-12 e k e 12
-27 e l e 27
0.851-0.827
3.14-25.00
0 e h e 13
-13 e k e 13
-18 e l e 18
no. of rflns
measd
indep
7818
5591
39 930
8153
7335
6957
Rint
abs cor
refinement method
0.0296
ψ scans
0.0277
0.0110
ψ scans
semiempirical from equivalents
full-matrix least squares on F2
no. of data/restraints/params
5591/43/394
0.999
0.0361
0.0868
1.159
8153/40/446
1.214
0.0476
0.1023
0.907
6957/465/487
1.061
0.0283
0.0796
0.504
S (F2)
R1a
wR2b
largest diff peak (e Å-3
)
max Dr (e Å-3
)
-0.618
-0.996
-0.525
a
b
2
R1 ) ∑||Fo| - |Fc||/∑|Fo| for reflections with I > 2σ(I). wR2 ) [∑[w(Fo - Fc2)2]/∑[w(Fo2)2]0.5 for all reflections; w-1 ) σ2(F2) + (aP)2
+ bP, where P ) (2Fc + Fo2)/3 and a and b are constants set by the program.
2
[Rh (CF 3)(CNXy)3(P P h 3)] (8a ). A solution of 2a , prepared
from 1a (119 mg, 0.24 mmol) and Me3SiCF3 (0.18 mL of a 2.0
M solution in THF, 0.36 mmol) in THF (5 mL), was treated
with XyNC (97 mg, 0.74 mmol) at room temperature and
stirred for 1 h. The resulting orange solution was concentrated
(ca. 1 mL), n-hexane (5 mL) was added, and a yellow solid
precipitated. The solution was removed by means of a pipet,
and the solid was washed with n-hexane (2 × 5 mL) and dried
in vacuo. Yield: 170 mg, 85%. Mp: 104-106 °C. Anal. Calcd
for C46H42N3F3PRh: C, 66.73; H, 5.11; N, 5.10. Found: C,
66.69; H, 5.30; N, 5.15. IR (cm-1): ν(CtN) 2038 (vs). 1H NMR
(300.1 MHz, C6D6): δ 7.67 (m, 6 H, H2, Ph3P), 6.97 (m, 9 H,
H3 + H4, Ph3P), 6.70 (AB2 m, 9 H, CH, Xy), 2.12 (s, 18 H,
Me). 13C{1H} NMR (50.3 MHz, C6D6): δ 163.6 (br s, CtN),
(m, 15 H, CH, Xy, H3, C6H4), 3.22 (s, 9 H, OMe), 2.13 (s, 18 H,
Me, Xy). 13C{1H} NMR (100.8 MHz, THF/d6-DMSO (ext)): δ
2
164.0 (br s, CtN), 161.1 (s, C4, C6H4), 135.5 (d, J PC ) 14.2
Hz, C2, C6H4), 134.2 (s, C2, Xy), 129.1 (s br, C1, Xy), 128.2 (br
1
d, C1, C6H4, J PC ) 38.8 Hz), 127.4 (s, C3, Xy), 126.7 (s, C4,
3
Xy), 113.5 (d, C3, C6H4, J PC ) 9.9 Hz), 54.6 (s, OMe), 17.9 (s,
Me). The signal corresponding to the CF3 carbon was not
observed. 19F NMR (188.3 MHz, d8-toluene): 23 °C, δ 1.3 (br
2
3
s); -60 °C, δ 4.6 (dd, J RhF ) 7.5 Hz, J PF ) 61.4 Hz). 31P{1H}
NMR (81.0 MHz, d8-toluene): 23 °C, δ 32.3 (br s); -60 °C, δ
38.3 (dq, J RhP ) 76.1 Hz, J PF ) 61.0 Hz).
1
3
[Rh (C3F 7)(CNXy)3(P P h 3)] (8c). A solution of 2c, prepared
from 1a (128 mg, 0.26 mmol) and Me3SiC3F7 (0.11 mL, 0.52
mmol) in THF (5 mL), was treated with XyNC (102 mg, 0.78
mmol) at room temperature and stirred for 1 h. The resulting
orange solution was concentrated to ca. 0.5 mL, and n-pentane
(5 mL) was added. An oil precipitated, which was converted
into a yellow solid by stirring for 10 min at 0 °C. The solution
was removed by means of a pipet, and the solid was washed
with n-pentane (2 × 5 mL) and dried under vacuum. Yield:
199 mg, 82.5%. Mp: 78 °C. Anal. Calcd for C48H42N3F7PRh:
C, 62.14; H, 4.56; N, 4.53. Found: C, 62.02; H, 4.47; N, 4.54.
1
137.2 (d, C1, Ph, J PC ) 25.9 Hz), 134.8 (s, C2, Xy), 134.5 (d,
2
C2, Ph, J PC ) 14.2 Hz), 129.5 (s, C4, Ph), 129.2 (s, C1, Xy),
3
128.4 (d, C3, Ph, J PC ) 8.8 Hz), 127.8 (s, C4, Xy), 127.2 (s,
C3, Xy), 18.7 (s, Me). The signal corresponding to the CF3
carbon was not observed. 19F NMR (188.3 MHz, d8-toluene):
2
2
77 °C, δ -8.4 (d, J RhF ) 23.3 Hz); 58 °C, δ -7.1 (d, J RhF
)
2
21.5 Hz); 22 °C, δ -1.2 (br s); CD2Cl2, -80 °C, δ 3.1 (dd, J RhF
) 8.1 Hz, J PF ) 59.8 Hz). 31P{1H} NMR (81.0 MHz, d8-
3
1
toluene): 77 °C, δ 2.3 (br s); 58 °C, δ 4.1 (br s); 22 °C, δ 20.1
(v br s); CD2Cl2, -80 °C, δ 42.5 (dq, J RhP ) 76.5 Hz, J PF
IR (cm-1): ν(CtN) 2035 (vs). H NMR (200.1 MHz, C6D6): δ
1
3
)
7.51 (m, 6 H, H2, PPh3), 7.00 (m, 9 H, H3 + H4, PPh3), 6.64
(AB2 m, 9 H, CH, Xy), 2.12 (s, 18 H, Me). 13C{1H} NMR (100.8
MHz, C6D6): δ 160.9 (br s, CtN), 137.9 (br s, C1, PPh3), 135.7
60.1 Hz).
[Rh (CF 3)(CNXy)3{P (C6H4OMe-4)3}] (8b). This compound
was prepared as for 8a from 1b (115 mg, 0.22 mmol), Me3-
SiCF3 (0.22 mL of a 2.0 M solution in THF, 0.44 mmol) in THF
(7 mL), and XyNC (89 mg, 0.66 mmol). n-Pentane was used
instead of n-hexane to precipitate the complex. Yield: 191 mg,
94.5%. Mp: 106-108 °C dec. Anal. Calcd for C49H48O3N3F3-
PRh: C, 64.12; H, 5.27; N, 4.58. Found: C, 63.98; H, 5.67; N,
2
(s, C2, Xy), 134.9 (d, J PC ) 16.2 Hz, C2, PPh3), 129.8 (s, C4,
3
PPh3), 129.1 (d, J PC ) 8.1 Hz, C3, PPh3), 128.9 (s, C3, Xy),
128.5 (s, C4, Xy), 19.1 (s, Me); the signals of C3F7 group and
C1 Xy group carbons were not observed. 19F NMR (188.3 MHz,
d8-toluene): 80 °C, δ -78.3 (t, 3 F, CF3, 4J FF ) 10.3 Hz), -84.8
(br m, 2 F, R-F), -117.7 (s, 2 F, â-F); 25 °C, δ -78.1 (t, 3 F,
1
4
4.60. IR (cm-1): ν(CtN) 2028 (vs). H NMR (200.1 MHz, d8-
CF3, J FF ) 10.4 Hz), -81.8 (br m, 2 F, R-F), -116.7 (s, 2 F,
toluene, 23 °C): δ 7.84-7.69 (m, 6 H, H2, C6H4), 6.78-6.56
â-F); -84 °C, δ -62.8 (br m, 2 F, R-F), -76.9 (s, 3 F, CF3),

Rhodium(I) Perfluoroalkyl Complexes
Organometallics, Vol. 23, No. 21, 2004 4881
-112.6 (s, 2 F, â-F). 31P{1H} NMR (81.0 MHz, d8-toluene): 80
(br s, CO); d8-toluene, -70 °C, δ 184.3 (ddq, *CO; 1J RhC ) 71.1
1
2
3
°C, δ 12.4 (br s); 25 °C, δ 9.8 (br s); -84 °C, δ 44.8 (dt, J RhP
)
Hz, J PC ) 14.0 Hz, J CF ) 10.7 Hz). 19F NMR (188.3 MHz,
3
3
75.9 Hz, J PF ) 37.8 Hz).
d8-toluene): 25 °C, δ 7.8 (br d, J PF ) 61.7 Hz); -70 °C, δ 8.2
3
3
2
Rea ction of 2a w ith t-Bu NC in a 1:3 Mola r Ra tio. A
solution of 2a , prepared from 1a (11 mg, 0.022 mmol) and Me3-
SiCF3 (0.040 mmol) in d8-toluene or THF (0.5 mL), was treated
with t-BuNC (0.066 mmol) at room temperature, and the NMR
spectra were measured after 30 min. 1H NMR (200.1 MHz,
d8-toluene, 25 °C): δ 7.46 (m, 6 H, H2, Ph), 7.05 (m, 9 H, H3
+ H4, Ph), 0.97 (s, 27 H, t-Bu). 19F NMR (188.3 MHz): d8-
(ddq, J PF ) 60.8 Hz, J CF ) 10.3 Hz, J RhF ) 8.0 Hz). 31P{1H}
1
NMR (81.0 MHz, d8-toluene): 25 °C δ 32.2 (dq, J RhP ) 69.8
Hz, 3J PF ) 61.8 Hz); -70 °C, δ 31.7 (dqq, 1J RhP ) 68.9 Hz, 3J PF
2
) 60.9 Hz, J PC ) 15.4 Hz).
Cr ysta llogr a p h y. Data for compounds 4a and 8a were
measured on a Siemens P4/LT2 machine and for 7a on a
Bruker Smart Apex CCD machine. Data were collected using
monochromated Mo KR radiation in ω-scan mode. The struc-
tures were solved by the heavy-atom method, and all were
refined anisotropically on F2. Restraints to local aromatic ring
symmetry or light atom displacement factor components were
applied in some cases. Methyl groups were refined using rigid
groups, for compounds 4a and 7a . Other hydrogens were
refined using a riding mode. The fluorine atoms are disordered
over two sites in compound 4a . Crystal data for compounds
4a , 7a , and 8a are given in Table 2.
2
toluene, 25 °C, δ -9.9 (d, J RhF ) 24.6 Hz); d8-toluene, -70
°C, δ 3.7 (very broad), -7.9 (very broad); THF, 22 °C, δ -12.9
2
2
(d, J RhF ) 24.5 Hz); THF, -84 °C, δ 0.8 (br d, J RhF ) 60.1
Hz), -12.8 (very broad). 31P{1H} NMR (81.0 MHz): d8-toluene,
25 °C, δ 10.8 (br s); d8-toluene, -70 °C, δ 49.3 (very broad);
THF, 22 °C, δ 3.9 (br s); THF, -84 °C, δ 47.3 (br m).
[Rh (CF 3)(CO)3(P P h 3)] (9) a n d [Rh (CF 3)(13CO)3(P P h 3)]
(9*). Complex 1a (10 mg, 0.020 mmol) was placed in a NMR
tube fitted with a Young valve, and d8-toluene (0.5 mL) was
added. The yellow solution was treated with Me3SiCF3 (20 µL
of a 2.0 M solution in THF, 0.040 mmol) at room temperature,
the NMR tube was connected to the vacuum line, the solution
was frozen with N2(l), and the tube was then evacuated,
thawed, and then filled with CO (1 atm). The same steps were
repeated two times more to give an orange solution. Compound
9* was prepared in the same way using 13CO. Data for 9 are
as follows. IR (toluene, cm-1): ν(CÃ) 2012 (s). 1H NMR (200.1
MHz, C6D6, 25 °C): δ 7.34-7.25 (m, 6 H, H2, PPh3), 6.90 (m,
9 H, H3 + H4, PPh3). 19F NMR (188.3 MHz, C6D6, 25 °C): δ
Ack n ow led gm en t. We thank the Direccio´n General
de Investigacio´n and FEDER for financial support
(Grant BQU 2001-0133 and a “Ramo´n y Cajal” contract
to J .G.-R.).
Su p p or tin g In for m a tion Ava ila ble: Crystallographic
files in CIF format and crystallographic tables for compounds
4a , 7a , and 8a . This material is available free of charge via
the Internet at http://pubs.acs.org.
7.7 (br d, J PF ) 61.8 Hz). 31P{1H} NMR (81.0 MHz, C6D6, 25
3
1
3
°C): δ 31.9 (dq, J RhP ) 69.3 Hz, J PF ) 62.0 Hz). Data for 9*
are as follows. 13C{1H} NMR (50.3 MHz): C6D6, 25 °C, δ 188.5
OM049592A