On the reactivity toward ketones of new methyl amino complexes of Rh(III) and Ag(I). Synthesis of ortho-rhodiated acetophenone methyl imine complexes

Article abstract of DOI:10.1021/ic700963h

MeNH₂ reacts with silver salts AgX (2:1) to give [Ag(NH ₂Me)₂]X [X = TfO = CF₃SO₃ (1·TfO) and ClO₄ (1·ClO₄)]. Neutral mono(amino) Rh(III) complexes [Rh(Cp*)Cl₂(NH₂R)] [R = Me (2a), To = C₆H₄Me-4 (2b)] have been prepared by reacting [Rh(Cp*)Cl(μ-Cl)]₂ with RNH₂ (1:2). The following cationic methyl amino complexes have also been prepared: [Rh(Cp*)Cl(NH₂Me)(PPh₃)]TfO (3·TfO), from [Rh(Cp*)Cl₂(PPh₃)] and 1·TfO (1:1); [Rh(Cp*)Cl(NH₂R)₂]X, where R = Me, X = Cl, (4a·Cl), from [Rh(Cp*)Cl(μ-Cl)]₂ and MeNH₂ (1:4), or R = Me, X = ClO₄ (4a·ClO₄), from 4a·Cl and NaClO₄ (1:4.8), or R = To, X = TfO (4b·TfO), from [Rh(Cp*)Cl(μ-Cl)]₂, ToNH₂ and TlTfO (1:4:2); [Rh(Cp*)(NH₂Me)(^tBubpy)](TfO)₂ (Bubpy = 4,4′-di-tert-butyl-2,2′-bipyridine, 5·TfO), from 2a, TlTfO and ^tBubpy (1: 2:1) [Rh(Cp*)(NH₂Me) ₃](TfO)₂ (6·TfO) from [Rh(Cp*)Cl(μ-Cl)] ₂ and 1·TfO (1:4). 2-6 constitute the first family of methyl amino complexes of rhodium. 1 and 4a·ClO₄ react with acetone to give, respectively, the methyl imino complexes [Ag{N(Me)=CMe ₂}₂]X [X = TfO (7·TfO), ClO₄ (7·ClO₄)], and [Rh(Cp*)Cl(Me-imam)]ClO₄ [8·ClO₄, Me-imam = N,N′-N(Me)=C(Me)CH ₂C(Me)₂NHMe]. 7·X (X = TfO, ClO₄) are new members of the small family of methyl acetimino complexes of any metal whereas 8·ClO₄ results after a double acetone condensation to give the corresponding bis(methyl acetimino) complex and an aldol-like condensation of the two imino ligands. The acetimino complex [Ag(NH=CMe ₂)₂]ClO₄ reacts with [Rh(Cp*)Cl(imam)] ClO₄ [1:1, imam = N,N′-NH=C(Me)CH₂C(Me) ₂NH₂] to give [Rh(Cp*)(imam)(NH=CMe ₂)](ClO₄)₂ (9a·ClO₄). 8·ClO₄ reacts with AgClO₄ (1:1) in MeCN to give [Rh(Cp*)-(Me-imam)(NCMe)](ClO₄)₂ (9b·ClO ₄), which in turn reacts with XyNC (Xy = C₆H ₃Me₂-2,6) or with MeNH₂ (1:1) to give [Rh(Cp*)(Me-imam)L](ClO₄)₂ [L = XyNC (9c·ClO₄), MeNH₂ (9d·ClO₄)]. 6·TfO reacts with acetophenone to give [Rh(Cp*){C,N-C ₆H₄C(Me)=N(Me)-2}(NH₂Me)]TfO (10a·TfO), the first complex resulting from such a condensation and cyclometalation reaction. In turn, 10a·TfO reacts with isocyanides RNC (1:1) at room temperature to give [Rh(Cp*){C,N-C₆H₄C(Me)=NMe-2} (CNR)]TfO [R = ^tBu (10b·TfO), Xy (10c·TfO)], or 1:12 at 60°C to give [Rh-(Cp*){C,N-C(=NXy)C₆H₄C(Me)= N(Me)-2}(CNXy)]TfO (11·TfO). The crystal structures of 9a·ClO ₄·acetone-d₆,9c· ClO₄, and 10a·TfO have been determined.

Full text of DOI:10.1021/ic700963h

Inorg. Chem. 2007, 46, 8939−8949
On the Reactivity Toward Ketones of New Methyl Amino Complexes of
Rh(III) and Ag(I). Synthesis of Ortho-Rhodiated Acetophenone Methyl
Imine Complexes†
Jose´ Vicente,*,§ Mar´ıa Teresa Chicote,§ Inmaculada Vicente-Herna´ndez,§ and Delia Bautista‡
Grupo de Qu´ımica Organometa´lica, Departamento de Qu´ımica Inorga´nica, UniVersidad de
Murcia, Aptdo. 4021, 30071 Murcia, Spain, UniVersidad de Murcia, and SACE, Aptdo. 4021,
30071 Murcia, Spain
Received May 18, 2007
MeNH2 reacts with silver salts AgX (2:1) to give [Ag(NH2Me)2]X [X
Neutral mono(amino) Rh(III) complexes [Rh(Cp*)Cl2(NH2R)] [R Me (2a), To
by reacting [Rh(Cp*)Cl( -Cl)]2 with RNH2 (1:2). The following cationic methyl amino complexes have also been
prepared: [Rh(Cp*)Cl(NH2Me)(PPh3)]TfO (3 TfO), from [Rh(Cp*)Cl2(PPh3)] and 1 TfO (1:1); [Rh(Cp*)Cl(NH2R)2]X,
where R Me, X Cl, (4a Cl), from [Rh(Cp*)Cl( -Cl)]2 and MeNH2 (1:4), or R Me, X ClO4 (4a ClO4), from
4a Cl and NaClO4 (1:4.8), or R TfO (4b TfO), from [Rh(Cp*)Cl(
[Rh(Cp*)(NH2Me)(tBubpy)](TfO)2 (tBubpy
-di-tert-butyl-2,2 -bipyridine, 5
2:1); [Rh(Cp*)(NH2Me)3](TfO)2 (6 -Cl)]2 and 1 TfO (1:4). 2
methyl amino complexes of rhodium. 1 and 4a ClO4 react with acetone to give, respectively, the methyl imino
complexes [Ag N(Me) CMe2 2]X [X TfO (7 TfO), ClO4 (7 ClO4)], and [Rh(Cp*)Cl(Me-imam)]ClO4 [8 ClO4, Me-
imam N,N -N(Me) C(Me)CH2C(Me)2NHMe]. 7 X (X TfO, ClO4) are new members of the small family of
methyl acetimino complexes of any metal whereas 8 ClO4 results after a double acetone condensation to give the
corresponding bis(methyl acetimino) complex and an aldol-like condensation of the two imino ligands. The acetimino
complex [Ag(NH CMe2)2]ClO4 reacts with [Rh(Cp*)Cl(imam)]ClO4 [1:1, imam N,N -NH C(Me)CH2C(Me)2NH2]
to give [Rh(Cp*)(imam)(NH CMe2)](ClO4)2 (9a ClO4). 8 ClO4 reacts with AgClO4 (1:1) in MeCN to give [Rh(Cp*)-
(Me-imam)(NCMe)](ClO4)2 (9b ClO4), which in turn reacts with XyNC (Xy C6H3Me2-2,6) or with MeNH2 (1:1) to
give [Rh(Cp*)(Me-imam)L](ClO4)2 [L XyNC (9c ClO4), MeNH2 (9d ClO4)]. 6 TfO reacts with acetophenone to
give [Rh(Cp*) C,N-C6H4C(Me) N(Me)-2 (NH2Me)]TfO (10a TfO), the first complex resulting from such a condensation
and cyclometalation reaction. In turn, 10a TfO reacts with isocyanides RNC (1:1) at room temperature to give
[Rh(Cp*) C,N-C6H4C(Me) NMe-2 (CNR)]TfO [R TfO), Xy (10c TfO)], or 1:12 at 60 C to give [Rh-
tBu (10b
(Cp*) C,N-C( NXy)C6H4C(Me) N(Me)-2 (CNXy)]TfO (11 TfO). The crystal structures of 9a ClO4 acetone-d6, 9c
ClO4, and 10a TfO have been determined.
)
TfO
)
CF3SO3 (1‚TfO) and ClO4 (1‚ClO4)].
)
) C6H4Me-4 (2b)] have been prepared
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‚
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Introduction
poses after short periods of storage to give acetonine
(2,2,4,4,6-pentamethyl-2,3,4,5-tetrahydropyrimidine),2 we have
prepared a family of acetimino complexes of Au(I), Au(III),3,4
The synthesis of imino metal complexes is interesting
because some of these ligands are very unstable, and its
coordination offers an opportunity to study their properties.1
Thus, in spite of the instability of acetimine, which decom-
(1) Kukushkin, V. Y.; Pombeiro, A. J. L. Coord. Chem. ReV. 1999, 181,
147. Kukushkin, V. Y.; Pombeiro, A. J. L. Chem. ReV. 2002, 102,
1771.
(2) Findeisen, K.; Heitzer, H.; Deehnicke, K. Synthesis 1981, 702.
(3) Vicente, J.; Chicote, M. T.; Guerrero, R.; Saura-Llamas, I. M.; Jones,
P. G.; Ram´ırez de Arellano, M. C. Chem.sEur. J. 2001, 7, 638.
(4) Vicente, J.; Chicote, M.-T.; Abrisqueta, M.-D.; Guerrero, R.; Jones,
P. G. Angew. Chem., Int. Ed. Engl. 1997, 36, 1203. Vicente, J.;
Chicote, M. T.; Guerrero, R.; Ram´ırez de Arellano, M. C. Chem.
Commun. 1999, 1541.
† Dedicated to Profs. Juan Fornie´s, Jose´ Gimeno, and Miguel Yus on
the occasion of their 60th birthdays.
* To whom correspondence should be addressed. E-mail: jvs1@um.es
(J.V.), mch@um.es (M.T.C.).
§ Grupo de Qu´ımica Organometa´lica.
‡ SACE. To whom correspondence regarding the X-ray diffraction studies
should be addressed. E-mail: dbc@um.es.
10.1021/ic700963h CCC: $37.00
Published on Web 09/20/2007
© 2007 American Chemical Society
Inorganic Chemistry, Vol. 46, No. 21, 2007 8939

Vicente et al.
Ag(I),5 Rh(I),5 Rh(III),6,7 Pt(II), and Pt(IV),8 using in some
cases [Ag(NHdCMe2)2]+ or [Au(NHdCMe2)(PPh3)]+ as
efficient transmetalating agents. These complexes have
offered us the possibility of preparing the first heteronuclear
µ-acetimino complex of any metal, resulting from the
substitution of the NH proton in an acetimino complex of
platinum by the isolobal AuPPh3 fragment8 and also to
observe, for the first time, the metal-assisted aldol-type
condensation of two acetimino ligands to give a 4-imino-2-
methylpentan-2-amino (imam) Rh(III) complex.6
Chart 1. The New Ligands Present in the Reported Rh(III) Complexes
and an Atom Numbering Scheme for the Me-imam Ligand
acetone. Among the many complexes of Rh(III) with primary
amine ligands described so far, those with MeNH2 are rather
scarce.17
In this article, we also report the synthesis of new [Rh-
(III)]Cp* complexes containing the ligands (a) N,N′-MeNd
C(Me)CH2CMe2NHMe (Me-imam), (b) C,N-C6H4{C(Me)d
N(Me)}-2, or (c) C,N-C()NXy)C6H4{C(Me)dN(Me)}-2
(Chart 1). As far as we are aware, no complex of any of
these ligands has been reported so far for any metal.
To know more about the limits of such an aldol condensa-
tion reaction, we decided to study the synthesis and reactivity
of methyl acetimino Rh(III) complexes [Rh]N(Me)dCMe2
and related species. However, methanimines RR′CdNMe
(R, R′ ) H, Me) are very difficult to prepare; they require,
for example, pyrolysis of alkyl azides,9,10 reactions of ketones
with silazanes and silyl amines at 165 °C in the presence of
a catalyst,11 photolysis of azides in nitrogen at 12 K,12
vacuum gas-solid dehydrochlorination of N-chloroalky-
lamines or dehydrocyanation of alpha-aminonitriles,13 etc.
In addition, they tend to polymerize.9 For these reasons, the
methods for the synthesis of their few reported metal
complexes do not use the free imines. Thus, the unstable
methyl imino chromium complex [Cr(CO)4{N(Me)dCHMe}-
(PPh3)] was serendipitously obtained by irradiation of the
carbene complex [Cr(CO)4{C(Me)NHMe}(PPh3)],14 and the
methyl acetimino complexes [Pt(L){N(Me)dCMe2}]TfO
[LH ) 1,3-bis(piperidylmethyl)benzene, TfO ) CF3SO3],15
or [Au{N(Me)dCMe2}(PPh3)]TfO3 were prepared by react-
ing the corresponding [PtCl(L)] with AgTfO and MeNH2 in
acetone or [Au(NH2Me)(PPh3)]TfO with acetone, respec-
tively. The usually named η2-N,C-imino complexes, [M](η2-
N,C-CH2NMe), obtained by deprotonation of a dimethyl
amido ligand, Me2N-, do not actually contain the imine
H2CdNMe but the ligand (H2C-NMe)2-.16 In this article,
we report the synthesis of a new member of this small family,
[Ag{N(Me)dCMe2}2]+ and its use, along with that of our
complex [Au{N(Me)dCMe2}PPh3]TfO, to prepare methyl
acetimino Rh(III) complexes. With the same objective, we
describe reactions of methyl amino Rh(III) complexes with
Experimental Section
When not stated, the reactions were carried out at room
temperature without precautions to exclude light or atmospheric
oxygen or moisture. Melting points were determined on a Reichert
apparatus and are uncorrected. Elemental analyses were carried out
with a Carlo Erba 1106 microanalyzer. Molar conductivities were
measured on a ca. 5 × 10-4 mol‚L-1 acetone solution with a Crison
Micro CM2200 conductimeter. IR spectra were recorded on a
PerkinElmer 16F PC FTIR spectrometer with Nujol mulls between
polyethylene sheets. When not stated otherwise, NMR spectra were
recorded at room temperature in Bruker 200, 300, or 400 NMR
spectrometers. Chemical shifts are referred to TMS (1H, 13C) or
H3PO4 (31P). When needed, NMR assignments were performed with
the help of APT, HMBC, and HMQC experiments. The assignment
in 8‚ClO4 and 9‚ClO4 was made according to the numbering shown
18
in Chart 1. [Rh(Cp*)Cl(µ-Cl)]2 and [Rh(Cp*)Cl2(PPh3)]19 were
prepared according to literature methods. The complex [Rh(Cp*)-
Cl(tBubpy)]TfO (tBubpy ) 4,4′-di-tert-butyl-2,2′-bipyridine) was
prepared from [Rh(Cp*)Cl(µ-Cl)]2, TlTfO, and tBubpy (1:2:2, 2 h,
in CH2Cl2).20 Its homologous BF4 salt was mentioned in a previous
article,21 but no synthetic procedure or any other data were reported.
TlTfO was obtained from CF3SO3H and Tl2CO3 (Fluka). XyNC,
tBuNC, PPh3 (Fluka), ToNH2 (Merck), MeNH2 (33% in abs EtOH),
and AgClO4‚H2O (Aldrich) were purchased and used as received.
CH2Cl2 and acetone were distilled under nitrogen before use from
CaH2 and B2O3, respectively. The reactions involving silver
compounds were carried out protected from light.
Caution: Perchlorate salts of organic cations may be explosive.
Preparations on a larger scale than that reported herein should be
avoided.
Synthesis of [Ag(NH2Me)2]X [X ) TfO (1‚TfO), ClO4 (1‚
ClO4)]. AgX (X ) TfO, 500 mg, 1.95 mmol, X ) ClO4, 500 mg,
2.4 mmol) was reacted with MeNH2 (1‚TfO: 485 µL, 3.89 mmol;
(5) Vicente, J.; Chicote, M. T.; Guerrero, R.; Vicente-Herna´ndez, I.; Jones,
P. G. Inorg. Chem. 2003, 42, 7644.
(6) Vicente, J.; Chicote, M. T.; Guerrero, R.; Vicente-Herna´ndez, I.;
AÄ lvarez-Falco´n, M. M.; Jones, P. G.; Bautista, D. Organometallics
2005, 24, 4506.
(7) Vicente, J.; Chicote, M. T.; Guerrero, R.; Vicente-Herna´ndez, I.;
AÄ lvarez-Falco´n, M. M. Inorg. Chem. 2006, 45, 181.
(8) Vicente, J.; Chicote, M. T.; Guerrero, R.; Vicente-Herna´ndez, I.; Jones,
P. G.; Bautista, D. Inorg. Chem. 2006, 45, 5201.
(9) Bock, H.; Dammel, R. Chem. Ber. 1987, 120, 1961.
(10) Bock, H.; Dammel, R. J. Am. Chem. Soc. 1988, 110, 5261.
(11) Duffaut, N.; Dupin, J. P. Bull. Soc. Chim. Fr. 1966, 3205.
(12) Dunkin, I. R.; Thomson, P. C. P. Tetrahedron Lett. 1980, 21, 3813.
(13) Guillemin, J. C.; Denis, J. M. Tetrahedron 1988, 44, 4431.
(14) Sierra, M. A.; Fernandez, I.; Manchen˜o, M. J.; Gomez-Gallego, M.;
Torres, M. R.; Cossio, F. P.; Arrieta, A.; Lecea, B.; Poveda, A.;
Jimenez-Barbero, J. J. Am. Chem. Soc. 2003, 125, 9572.
(15) Jude, H.; Bauer, A. K.; Connick, W. B. Inorg. Chem. 2002, 41, 2275.
(16) Mayer, J. M.; Curtis, C. J.; Bercaw, J. E. J. Am. Chem. Soc. 1983,
105, 2651. Ahmed, K. J.; Chisholm, M. H.; Folting, K.; Huffman, J.
C. J. Am. Chem. Soc. 1986, 108, 989. Cai, H.; Chen, T.; Wang, X.;
Schultz, A. J.; Koetzle, T. F.; Xue, Z. Chem. Commun. 2002, 230.
(17) Hambley, T. W.; Lay, P. A. J. Chem. Soc., Chem. Commun. 1987,
865.
(18) White, C.; Yates, A.; Maitlis, P. M. Inorg. Synth. 1992, 29, 228.
(19) Kang, J. W.; Moseley, K.; Maitlis, P. M. J. Am. Chem. Soc. 1969, 91,
5970.
(20) 1H NMR (200 MHz, acetone-d6): δ 1.46 (s, 18 H, Me, tBu), 1.78 (s,
15 H, Me, Cp*), 7.92 (dd, 2 H, H5, 3JHH ) 6 Hz, 4JHH ) 2 Hz), 8.69
4
3
(d, 2 H, H3, JHH ) 2 Hz), 9.00 (d, 2 H, H6, JHH ) 6 Hz.
(21) Marx, T.; Wesemann, L.; Hagen, S. Z. Anorg. Allg. Chem. 2001, 627,
1146.
8940 Inorganic Chemistry, Vol. 46, No. 21, 2007

Ortho-Rhodiated Acetophenone Methyl Imine Complexes
1‚ClO4: 600.5 µL, 4.8 mmol) in Et2O (15 mL). The resulting
supension was stirred for 15 min, filtered, and the white solid
collected was washed with Et2O (3 × 5 mL) and suction dried.
1‚TfO. Yield: 584 mg, 94%, mp (dec): 147 °C. 1H NMR (400
MHz, dmso-d6): δ 2.40 (s, 3 H, Me), 3.40 (br, 2 H, NH2). 13C-
{1H} APT NMR (50 MHz, dmso-d6): δ 30.9 (Me). IR (cm-1):
νNH, 3326, 3282, 3178. ΛM (Ω-1 cm2 mol-1): 173. Anal. Calcd
for C3H10AgF3N2O3S: C, 11.29; H, 3.16; N, 8.78; S, 10.05.
Found: C, 11.40; H, 3.10; N, 8.40; S, 10.00.
1‚ClO4. Yield: 602 mg, 93%, mp (dec): 140 °C. 1H NMR (400
MHz, dmso-d6): δ 2.39 (s, 3 H, Me), 3.51 (br, 2 H, NH2). 13C-
{1H} NMR (75 MHz, dmso-d6): δ 31.02 (Me). IR (cm-1): νNH
3332, 3294, 3164. ΛM (Ω-1 cm2 mol-1): 140. Anal. Calcd for
C2H10AgClN2O4: C, 8.92; H, 3.74; N, 10.40. Found: C, 8.91; H,
3.78; N, 10.16.
an orange solid. Yield: 496 mg, 97%. mp (dec): 170 °C. 1H NMR
(300 MHz, dmso-d6): δ 1.63 (s, 15 H, Me, Cp*), 2.34 (t, 6 H, Me,
3JHH ) 6.0 Hz), 4.10 (br, 2 H, NH2), 4.25 (br, 2 H, NH2). 13C{1H}
APT NMR (75 MHz, dmso-d6): δ 8.4 (Me, Cp*), 31.4 (Me), 93.5
(d, C, Cp*, 1JCRh ) 8 Hz). IR (cm-1): νNH 3552, 3408, 3216, 3140.
Anal. Calcd for C12H25Cl2N2Rh: C, 38.83; H, 6.79; N, 7.55.
Found: C, 38.67; H, 6.96; N, 7.21.
Synthesis of [Rh(Cp*)Cl(NH2Me)2]ClO4 (4a‚ClO4). To a
suspension of 4a‚Cl (245 mg, 0.66 mmol) in THF (25 mL) was
added NaClO4‚H2O (443 mg, 3.15 mmol). The suspension was
stirred for 30 min and then concentrated under a vacuum to dryness.
The residue was stirred with CH2Cl2 (20 mL), and the suspension
was filtered through a short pad of Celite. The solution was
concentrated under a vacuum (5 mL) and Et2O (25 mL) was added.
The suspension was filtered, and the orange solid was washed with
Et2O (3 × 5 mL) and suction dried to give 4a‚ClO4. Yield: 250
Synthesis of [Rh(Cp*)Cl2(NH2R)] [R ) Me (2a), To (2b)].
To a solution of [Rh(Cp*)Cl(µ-Cl)]2 (2a: 250 mg, 0.40 mmol; 2b:
102.5 mg, 0.16 mmol) in CH2Cl2 (15 mL) was added NH2R (2a:
R ) Me, 100.7 µL, 0.81 mmol; 2b: R ) To, 35.5 mg, 0.33 mmol).
After 1 (2a) or 24 (2b) h of being stirred, the solution was
concentrated under a vacuum (1 mL) and Et2O (25 mL) was added.
The resulting suspension was filtered and the solid washed with
Et2O (3 × 5 mL) and dried by suction (2a) or under a vacuum for
12 h (2b) to give an orange solid.
1
mg, 87%, mp (dec): 190 °C. H NMR (400 MHz, dmso-d6): δ
1.61 (s, 15 H, Me, Cp*), 2.35 (t, 6 H, Me, 3JHH ) 6 Hz), 3.95 (br,
2 H, NH2), 4.02 (br, 2 H, NH2). 13C{1H} NMR (300 MHz, dmso-
d6): 8.3 (Me, Cp*), 31.3 (Me), 93.5 (d, C, Cp*, 1JCRh ) 8 Hz). IR
(cm-1): νNH 3280, 3242, 3164. ΛM (Ω-1 cm2 mol-1): 160. Anal.
Calcd for C12H25Cl2N2O4Rh: C, 33.12; H, 5.79; N, 6.44. Found:
C, 33.01; H, 6.03; N, 6.40.
Synthesis of [Rh(Cp*)Cl(NH2To)2]TfO (4b‚TfO). To a solution
of [Rh(Cp*)Cl(µ-Cl)]2 (100 mg, 0.16 mmol) in CH2Cl2 (15 mL)
was added ToNH2 (69.4 mg, 0.65 mmol) and TlTfO (114.4 mg,
0.32 mmol). The resulting suspension was stirred for 1h and then
filtered through a short pad of Celite. The solution was concentrated
under a vacuum (1 mL), Et2O (25 mL) was added, and the resulting
suspension was filtered. The orange solid collected was washed
with Et2O (3 × 5 mL) and suction dried to give 4b‚TfO. Yield:
163 mg, 79%, mp (dec): 270 °C. 1H NMR (400 MHz, CDCl3): δ
1.13 (s, 15 H, Me, Cp*), 2.31 (s, 6 H, Me, To), 4.59 (br, 2 H,
NH2), 6.37 (br, 2 H, NH2), 7.07 (m, 4 H, CH, To), 7.42 (m, 4 H,
CH, To). 13C{1H} APT NMR (100 MHz, CDCl3): δ 8.1 (Me, Cp*),
2a. Yield: 266 mg, 97%, mp (dec): 185 °C. 1H NMR (200 MHz,
3
CDCl3): δ 1.71 (s, 15 H, Me, Cp*), 2.64 (t, 3 H, Me, JHH ) 6
Hz), 3.01 (br, 2 H, NH2). 13C{1H} APT NMR (50 MHz, CDCl3):
1
δ 9.26 (Me, Cp*), 31.5 (Me), 93.3 (d, C, Cp*, JCRh ) 9 Hz). IR
(cm-1): νNH 3318, 3202, 3126. ΛM (Ω-1 cm2 mol-1): 2.5. Anal.
Calcd for C11H20Cl2NRh: C, 38.85; H, 5.93; N, 4.12. Found: C,
38.99; H, 6.15; N, 4.22.
2b. Yield: 130 mg, 94%, mp (dec): 300 °C. 1H NMR (400 MHz,
CDCl3): δ 1.44 (s, 15 H, Me, Cp*), 2.31 (s, 3 H, Me, To), 4.70
(br, 2 H, NH2), 7.09 (br, 4 H, CH, To). 13C{1H} APT NMR (50
MHz, CDCl3): δ 8.8 (Me, Cp*), 20.8 (Me, To), 93.7 (d, C, Cp*,
1JCRh ) 9 Hz), 120.2 (CH, To), 129.6 (CH, To), 139.6 (C). IR
(cm-1): νNH 3294, 3196, 3146, 3100. ΛM (Ω-1 cm2 mol-1): 1.
Anal. Calcd for C17H24Cl2NRh: C, 49.06; H, 5.81; N, 3.37.
Found: C, 49.53; H, 6.01; N, 3.24.
1
20.9 (Me, To), 95.1 (d, C, Cp*, JCRh ) 9 Hz), 121.5 (CH, To),
129.6 (CH, To), 135.4 (C), 139.0 (C). IR (cm-1): νNH 3214, 3188,
3126. ΛM (Ω-1 cm2 mol-1): 127. Anal. Calcd for C25H33ClF3N2O3-
RhS: C, 47.14; H, 5.22; N, 4.40: S, 5.03. Found C, 46.80; H,
5.33; N, 4.30; S, 4.68.
Synthesis of [Rh(Cp*)Cl(NH2Me)(PPh3)]TfO‚H2O (3‚TfO).
To a solution of [Rh(Cp*)Cl2(PPh3)]19 (200 mg, 0.35 mmol) in CH2-
Cl2 (25 mL) was added 1‚TfO (112 mg, 0.35 mmol). The resulting
white suspension was stirred for 30 min and filtered through a short
pad of Celite. The solution was concentrated under a vacuum (2
mL) and Et2O (20 mL) was added. The suspension was filtered,
and the solid was washed with Et2O (3 × 5 mL) and suction dried
to give 3‚TfO as an orange solid. Yield: 225 mg, 90%, mp (dec):
Synthesis of [Rh(Cp*)(NH2Me)(tBubpy)](TfO)2 (5‚TfO). To
a solution of [Rh(Cp*)Cl2(NH2Me)](2a)(100 mg, 0.29 mmol) in
acetone (15 mL) was added TlTfO (208 mg, 0.59 mmol) and
tBubpy (80 mg, 0.29 mmol). After stirring the suspension for 7 h,
it was filtered through a short pad of Celite. The solution was
concentrated under a vacuum to dryness, and Et2O (5 mL) was
added. The suspension was filtered, and the solid was suction dried
to give 5‚TfO as a yellow solid. Yield: 238 mg, 97%, mp (dec):
1
140 °C. H NMR (300 MHz, CDCl3): δ 1.49 (d, 15 H, Me, Cp*,
1
t
3
4JHP ) 1 Hz), 1.71 (s, 2 H, H2O), 2.44 (t, 3 H, Me, JHH ) 6 Hz),
214 °C. H NMR (400 MHz, acetone-d6) δ 1.45 (s, 18 H, Me, -
Bu), 1.81 (s, 15 H, Me, Cp*), 1.94 (t, 3 H, Me, 3JHH ) 6 Hz), 4.42
(br, 2 H, NH2), 8.04 (dd, 2 H, H5, JHH ) 5.93 Hz, JHH ) 1.80
5.03 (br, 2 H, NH2), 7.52-7.63 (m, 15 H, Ph). 13C{1H} APT NMR
3
4
3
(75 MHz, CDCl3): δ 8.9 (d, Me, Cp*, JCP ) 1 Hz), 32.5 (Me),
4
3
100.4 (dd, C, Cp*, 1JCRh ) 7 Hz, 2JCP ) 3 Hz). 127.4 (ipso-C, 1JCP
) 45 Hz), 129.1 (d, ortho- or meta-C, JCP ) 8 Hz), 131.6 (d, para-
C, 4JCP ) 2 Hz), 134.6 (m, ortho- or meta-C). 31P{1H} NMR (162
MHz, CDCl3): δ 34.55 (d, 1JPRh ) 141 Hz). IR (cm-1): νNH 3306,
3232, 3151. ΛM (Ω-1 cm2 mol-1): 132. Anal. Calcd for C30H37-
ClF3NO4PRhS: C, 49.09; H, 5.08; N, 1.91; S, 4.37. Found: C,
48.94; H, 5.07; N, 1.99; S, 3.96.
Hz), 8.81 (d, 2 H, H3, JHH ) 1.80 Hz), 9.13 (d, 2 H, H6, JHH
)
5.93 Hz). 13C{1H} NMR (75 MHz, acetone-d6): 8.5 (Me, Cp*),
t
t
3.36 (Me, Bu), 30.67 (Me, NH2Me), 36.5 (C, Bu), 99.0 (d, C,
Cp*, JCRh ) 8 Hz), 122.7 (C3), 126.9 (C5), 153.1 (C6), 156.1
1
(C2), 166.8 (C4). IR (cm-1): νNH 3267, 3239, 3158. ΛM (Ω-1 cm2
mol-1): 210. Anal. Calcd for C31H44N3O6S2F6Rh: C, 44.55; H,
5.31; N, 5.03; S, 7.67. Found: C, 44.60; H, 5.26; N, 4.74; S, 7.20.
Synthesis of [Rh(Cp*)(NH2Me)3](TfO)2 (6‚TfO). To a solution
of [Rh(Cp*)Cl(µ-Cl)]2 (250 mg, 0.40 mmol) in CH2Cl2 (25 mL)
was added 1‚TfO (516 mg, 1.62 mmol). The resulting suspension
was stirred for 30 min and then concentrated under a vacuum to
dryness. The residue was stirred with acetone (15 mL), and the
Synthesis of [Rh(Cp*)Cl(NH2Me)2]Cl (4a‚Cl). To a solution
of [Rh(Cp*)Cl(µ-Cl)]2 (400 mg, 0.65 mmol) in CH2Cl2 (15 mL)
was added MeNH2 (322.3 µL, 2.59 mmol). The resulting orange
suspension was stirred for 1 h and then filtered. The solid was
washed with Et2O (3 × 5 mL) and suction dried to give 4a‚Cl as
Inorganic Chemistry, Vol. 46, No. 21, 2007 8941

Vicente et al.
1
suspension was filtered through a short pad of Celite. The solution
was concentrated under a vacuum (2 mL), and Et2O (25 mL) was
added. The resulting suspension was filtered, and the yellow solid
collected was washed with Et2O (3 × 5 mL) and suction dried to
187 °C. H NMR (300 MHz, acetone-d6): δ 1.19 (s, 3 H, Me),
1.45 (s, 3 H, Me), 1.81 (s, 15 H, Me, Cp*), 2.07 (d, 1 H, CH2, 2JHH
) 17 Hz), 2.28 (s, 3 H, Me), 2.41 (s, 3 H, Me), 2.45 (d, 3 H, Me,
4JHH ) 2 Hz), 2.63 (d, 1 H, CH2, JHH ) 17 Hz), 2.83 (br, 2 H,
2
1
2
2
give 6‚TfO. Yield: 479 mg, 94%, mp (dec): 198 °C. H NMR
H2O), 4.04 (d, 1 H, NH2, JHH ) 12 Hz), 4.58 (d, 1 H, NH2, JHH
) 12 Hz), 9.68 (s, 1 H, NH), 10.76 (s, 1 H, NH). 13C{1H} APT,
HMQC, NMR (50 MHz, acetone-d6): δ 8.9 (Me, Cp*), 24.7 (Me6),
26.8 (NdCMe trans to Rh), 30.0 (NdCMe trans to H), 30.1 (Me7),
31.3 (d, Me5, 3JCRh ) 1 Hz) 47.5 (C2), 49.7 (C3), 98.2 (d, C, Cp*,
(300 MHz, dmso-d6): δ 1.62 (s, 15 H, Me, Cp*), 2.33 (t, 9 H, Me,
3
3JHH ) 6 Hz), 4.00 (d, 6 H, NH2, JHH ) 6 Hz). 13C{1H} APT
NMR (75 MHz, dmso-d6): δ 8.0 (Me, Cp*), 31.1 (Me), 94.7 (d,
C, Cp*, 1JCRh ) 8 Hz), 120.7 (q, C, TfO, 1JCF ) 322 Hz). IR (cm-1):
νNH 3288, 3264, 3184. ΛM (Ω-1 cm2 mol-1): 225. Anal. Calcd
for C15H30F6N3O6RhS2: C, 28.62; H, 4.80; N, 6.68; S, 10.19.
Found: C, 28.88; H, 5.08; N, 6.67; S, 10.19.
1JCRh ) 8 Hz), 189.4 (d, CdN, JCRh ) 1 Hz), 193.5 (CdN). IR
2
(cm-1): νNH 3281, 3251, 3161; νCdN 1653, 1651. ΛM (Ω-1 cm2
mol-1): 213. Anal. Calcd for C19H38Cl2N3O9Rh: C, 36.43; H, 6.11;
N, 6.70. Found: C, 36.36; H, 5.97; N, 6.83. Crystals suitable for
an X-ray diffraction study were obtained from acetone-d6 and Et2O
by the liquid diffusion method.
Synthesis of [Ag{N(Me))CMe2}2]X [X ) TfO (7‚TfO), ClO4
(7‚ClO4)]. 1‚TfO or 1‚ClO4 (ca. 100 mg) was stirred in acetone
(10 mL) for 1 h, in the dark. The solvent was removed under a
vacuum to give an oily material, which was shown by 1H NMR to
contain only the title complex. Although the acetone solutions of
7‚TfO are stable for longer periods than those of 7‚ClO4, we
recommend in both cases to use them freshly prepared.
Synthesis of [Rh(Cp*){N,N′-N(Me)dC(Me)CH2C(Me)2NHMe}-
(NCMe)] (ClO4)2 (9b‚ClO4). To a solution of 8‚ClO4 (354 mg,
0.69 mmol) in MeCN (15 mL) was added AgClO4 (142.4 mg, 0.69
mmol). A suspension immediately formed, which was stirred for
15 min and then concentrated under a vacuum to dryness. The
residue was stirred with CH2Cl2 (20 mL), and the suspension was
filtered through a short pad of Celite. The solution was concentrated
under a vacuum (2 mL) and Et2O (25 mL) was added. The resulting
suspension was filtered, and the yellow solid collected was washed
with Et2O (3 × 5 mL) and suction dried to give 9b‚ClO4. Yield:
7‚TfO. 1H NMR (400 MHz, CDCl3): δ 2.06 (q, not well
5
resolved, 3 H, CMe trans to Ag, JHH ) 0.4 Hz), 2.33 (q, 3 H,
5
CMe trans to NMe, JHH ) 1.2 Hz), 3.35 (m, 3 H, NMe). The
nature of 7‚TfO was confirmed by reacting it with [AuCl(PPh3)]
and isolating [Au{N(Me)dCMe2}(PPh3)]TfO (82% yield).3
7‚ClO4. 1H NMR (200 MHz, CDCl3): δ 2.09 (q, not well
1
5
374 mg, 88%. mp (dec): 170 °C. H NMR (400 MHz, acetone-
d6): δ 0.88 (s, 3 H, Me6), 1.53 (s, 3 H, Me7), 1.84 (s, 15 H, Me,
Cp*), 2.39 (d, 1 H, CH2, JHH ) 18 Hz), 2.46 (s, 3 H, Me5), 2.78
resolved, 3 H, CMe trans to Ag, JHH ) 0.4 Hz), 2.36 (q, 3 H,
CMe trans to NMe, 5JHH ) 1.2 Hz), 3.36 (m, 3 H, NMe). 13C{1H}
NMR (75 MHz, dmso-d6): δ 18.93 (Me), 32.44 (Me), 41.93 (Me),
178.01 (CMe2).
2
(d, 3 H, Me8, 3JHH ) 5.7 Hz), 2.99 (d, 1 H, CH2, 2JHH ) 17.5 Hz),
3.81 (s, 3 H, Me4), 4.65 (br, 1 H, NH). 1H NMR (400 MHz,
acetone-d6, -80 °C): A/B molar ratio ) 1:3.6. Isomer A: δ 0.73
(s, 3 H, Me6), 1.41 (s, 3 H, Me7), 1.78 (s, 15 H, Me, Cp*), 2.40
(s, 3 H, Me5), 2.71 (s, 3 H, MeCN or Me7), 3.98 (s, 3 H, Me4),
5.20 (br, 1 H, NH). Isomer B: δ 0.77 (s, 3 H, Me6), 1.40 (s, 3 H,
Me7), 1.85 (s, 15 H, Me, Cp*), 2.30 (d, 1 H, CH2, 2JHH ) 16 Hz),
2.38 (s, 3 H, Me5), 2.72 (s, 3 H, MeCN or Me8), 2.98 (d, 1 H,
Synthesisof[Rh(Cp*)Cl{N,N′-N(Me)dC(Me)CH2C(Me)2NHMe}]-
ClO4 (8‚ClO4). A solution of 4a‚ClO4 (145 mg, 0.33 mmol) in
acetone (15 mL) was refluxed for 2 h and then filtered through a
short pad of Celite. The solution was concentrated under a vacuum
(2 mL) and, upon the addition of Et2O (25 mL), a suspension
formed, which was filtered, and the orange solid collected washed
with Et2O (3 × 5 mL) and suction dried to give 8‚ClO4. Yield:
CH2, JHH ) 16 Hz), 3.77 (s, 3 H, Me4), 4.84 (br, 1 H, NH). 13C-
2
1
157 mg, 91%. mp (dec): 221 °C. H NMR (300 MHz, CDCl3):
{1H} APT NMR (100 MHz, acetone-d6): δ 4.0 (MeCN), 9.1 (Me,
Cp*), 19.8 (Me6), 26.2 (Me5), 26.6 (Me7), 37.3 (Me8), 47.2 (Me4),
54.7(C2), 56.7 (C3), 100.0 (br, C, Cp*), 186.9 (C1). IR (cm-1):
νNH 3248 (br); νCtN 2316, 2288; νCdN 1708, 1658. ΛM (Ω-1 cm2
mol-1): 210. Anal. Calcd for C20H36Cl2N3O8Rh: C, 38.72, H, 5.85;
N, 6.77. Found: C, 38.30; H, 6.05; N, 6.45. MS (FAB+): (m/z,
%) [M+ - MeCN] 379.1, 100; [M+ + H2O] 219.2, 15.
A/B molar ratio ) 1:1. Isomer A: δ 0.82 (s, 3 H, Me6), 1.56 (s,
3 H, Me7), 1.71 (s, 15 H, Me, Cp*), 2.33 (s, 3 H, Me5), 2.66 (d,
3
2
3 H, Me8, JHH ) 6 Hz), 2.71 (d, 1 H, CH2, JHH ) 14 Hz), 2.97
2
(d, 1 H, CH2, JHH ) 14 Hz), 3.62 (s, 3 H, Me4), 4.24 (br, 1 H,
NH). Isomer B: δ 1.21 (s, 3 H, Me6), 1.36 (s, 3 H, Me7), 1.74 (s,
15 H, Me, Cp*), 2.42 (s, 3 H, Me5), 2.51 (m, 2 H, CH2), 2.73 (d,
3
3 H, Me8, JHH ) 6 Hz), 3.55 (s, 3 H, Me4). 13C{1H} APT NMR
(75 MHz, CDCl3): Isomer A: δ 8.9 (Me, Cp*), 19.8 (Me6), 26.0
(Me5), 27.0 (Me7), 36.0 (Me8), 46.6 (Me4), 54.2 (C2), 55.8 (C3),
96.0 (d, C, Cp*, 1JCRh ) 8 Hz), 182.9 (C1). Isomer B: δ 9.8 (Me,
Cp*), 25.0 (Me5), 25.3 (Me7), 26.0 (Me6), 34.9 (Me8), 45.5 (Me4),
Synthesis of [Rh(Cp*){N,N′-N(Me)dC(Me)CH2C(Me)2NHMe}-
(CNXy)] (ClO4)2 (9c‚ClO4). To a solution of 9b‚ClO4 (100 mg,
0.16 mmol) in acetone (15 mL) was added XyNC (21.2 mg, 0.16
mmol). After 2 h of being stirred, the yellow solution was
concentrated under a vacuum (1 mL) and, upon addition of Et2O
(25 mL), a suspension formed, which was filtered. The lemon-
yellow solid collected was washed with Et2O (3 × 5 mL) and air-
dried to give 9c‚ClO4. Yield: 106 mg, 92%. mp (dec): 185 °C.
1H NMR (400 MHz, dmso-d6): A/B molar ratio ) 1:1. Isomer A:
δ 0.81 (s, 3 H, Me6), 1.42 (s, 3 H, Me7), 1.85 (s, 15 H, Me, Cp*),
2.07 (d, 1 H, CH2, 2JHH ) 15 Hz), 2.38 (s, 3 H, Me5), 2.47 (s, 6 H,
Me, Xy), 2.65 (d, 3 H, Me8, 3JHH ) 6 Hz), 2.92 (d, 1 H, CH2, 2JHH
) 15 Hz), 3.64 (s, 3 H, Me4), 4.8 (br, 1 H, NH), 7.34-7.48 (various
m, 3 H, CH, Xy). Isomer B: δ 1.21 (s, 3 H, Me6), 1.22 (s, 3 H,
Me7), 1.85 (s, 15 H, Me, Cp*), 1.99 (d, 1 H, CH2, 2JHH ) 14 Hz),
2.35 (s, 3 H, Me5), 2.51 (s, 6 H, Me, Xy), 2.62 (d, 3 H, Me8, 3JHH
) 6 Hz), 2.98 (d, 1 H, CH2, 2JHH ) 4 Hz), 3.56 (s, 3 H, Me4), 5.25
(br, 1 H, NH), 7.34-7.48 (various m, 3 H, CH, Xy). 13C{1H} APT
NMR (50 MHz, dmso-d6): δ 8.90 (Me, Cp*), 9.6 (Me), 18.7 (Me,
1
56.6 (C2), 57.1 (C3), 95.9 (d, C, Cp*, JCRh ) 8 Hz), 183.4 (C1).
IR (cm-1): νNH 3256, 3240; νCdN 1659, 1652. ΛM (Ω-1 cm2 mol-1):
158. Anal. Calcd for C18H33Cl2N2O4Rh: C, 41.96, H, 6.46; N,
5.44. Found: C, 41.71; H, 6.49; N, 5.33. MS (FAB+): (m/z, %)
415 (M+, 100) 380 (M+ - Cl, 10).
Synthesis of [Rh(Cp*){N,N′-NHdC(Me)CH2C(Me)2NH2}-
(NHdCMe2)] (ClO4)2‚H2O (9a‚ClO4). To a solution of [Rh(Cp*)-
7
Cl{NHdC(Me)CH2C(Me)2NH2}]ClO4 (101 mg, 0.21 mmol) in
CH2Cl2 (25 mL) was added [Ag(NHdCMe2)2]ClO4 (67 mg, 0,21
mmol). A white suspension immediately formed that was stirred
for 30 min and then filtered through a short pad of Celite. The
solution was concentrated under a vacuum (1 mL), and Et2O was
added to precipitate a yellow solid that was filtered, washed with
Et2O (3 × 5 mL), and dried by suction and then in an oven at 60
°C for 8 h to give 9a‚ClO4‚H2O. Yield: 121 mg, 96%. mp (dec):
8942 Inorganic Chemistry, Vol. 46, No. 21, 2007

Ortho-Rhodiated Acetophenone Methyl Imine Complexes
Xy), 25.5 (Me), 26.4 (Me), 39.4 (Me8), 49.7 (Me4), 53.3 (C3),
55.7 (C2), 103.3 (d, C, Cp*, 1JCRh ) 7 Hz), 128.5 (meta-C), 130.9
(para-C), 136.1 (orto-C), 187.6 (C1). IR (cm-1) Isomer A: νNH
3240; νCtN 2166; νCdN 1656. ΛM (Ω-1 cm2 mol-1): 227. Anal.
Calcd for C27H42Cl2N3O8Rh: C, 45.65; H, 5.96; N, 5.91. Found:
C, 45.40; H, 6.05; N, 5.74. Crystals of 9c‚ClO4 suitable for an
X-ray diffraction study were obtained from acetone and Et2O by
the liquid diffusion method.
mixture was refluxed for 3 h (10b‚TfO) or 3 days (10c‚TfO) and
then filtered through a short pad of Celite. In the case of 10b‚TfO,
the solution was concentrated under a vacuum to dryness, and the
residue was washed with n-pentane (3 × 5 mL) and suction dried
to give a yellow solid. In the case of 10c‚TfO, the solution was
concentrated to 1 mL, and Et2O (30 mL) was added. The resulting
suspension was filtered, and the yellow solid collected was washed
with Et2O (3 × 10 mL) and suction dried.
1
10b‚TfO. Yield: 117 mg, 71%. mp (dec): 152 °C. H NMR
Synthesis of [Rh(Cp*){N,N′-N(Me)dC(Me)CH2C(Me)2NHMe}-
(NH2Me)](ClO4)2 (9d‚ClO4). To a suspension of 9b‚ClO4 (242
mg, 0.39 mmol) in CH2Cl2 (15 mL) was added NH2Me (48.5 µL,
0.39 mmol). After 1 h of stirring, the suspension was filtered and
the solid collected was washed successively with CH2Cl2 (2 × 5
mL) and Et2O (2 × 5 mL). It was dried by suction and then in an
oven at 60 °C for 3 days to give 9d‚ClO4‚H2O as a yellow solid.
t
(300 MHz, CDCl3): δ 1.32 (s, 9 H, Me, Bu), 1.78 (s, 15 H, Me,
Cp*), 2.49 (s, 3 H, Me), 3.74 (s, 3 H, Me), 7.18 (td, 1 H, CH, 3JHH
4
3
4
) 8 Hz, JHH ) 1 Hz), 7.28 (td, 1 H, CH, JHH ) 8 Hz, JHH ) 1
Hz), 7.47-7.51 (m, 2 H, CH). 13C{1H} APT NMR (75 MHz,
CDCl3): δ 9.5 (Me, Cp*), 15.8 (d, CMe, 3JCRh ) 2 Hz), 30.4 (Me,
tBu), 46.0 (Me, NMe), 58.9 (C, Bu), 101.2 (d, C, Cp*, JCRh ) 5
t
1
Hz), 124.3 (CH, Ph), 128.4 (CH, Ph), 131.4 (d, CH, Ph, 2JCRh ) 1
1
Yield: 230 mg, 97%. mp (dec): 168 °C. H NMR (200 MHz,
1
Hz), 135.7 (CH, Ph), 146.73 (ipso-C, Ph), 174.0 (d, C-Rh, JCRh
acetone-d6): A/B molar ratio ) 2.5:1. Isomer A: δ 1.02 (s, 3 H,
Me), 1.56 (s, 3 H, Me), 1.81 (s, 15 H, Me, Cp*), 2.40 (d, 1 H,
CH2, 2JHH ) 16 Hz) 2.51 (s, 3 H, Me), 2.67-2.72 (m, 6 H, MeNH2
) 29 Hz), 182.0 (CdN). IR (cm-1): νCtN 2182; νCdN 1602. ΛM
(Ω-1 cm2 mol-1): 158. Anal. Calcd for C25H34F3N2O3RhS: C,
49.84; H, 5.69; N, 5.65; S, 5.32. Found: C, 49.52; H, 5.86; N,
5.78; S, 5.15.
2
+ Me8), 3.02 (br, 2 H, H2O), 3.14 (d, 1 H, CH2, JHH ) 16 Hz),
3.84 (s, 3 H, Me4), 3.98 (br, 2 H, NH2), 4.67 (br, 1 H, NH). Isomer
B: δ 1.41 (s, 3 H, Me), 1.48 (s, 3 H, Me), 1.82 (s, 15 H, Me,
Cp*), 2.43 (d, 1 H, CH2, 2JHH ) 15 Hz), 2.47 (s, 3 H, Me5), 2.67-
1
10c‚TfO. Yield: 281 mg, 79%. mp: 117 °C. H NMR (300
MHz, CDCl3): δ 1.88 (s, 15 H, Me, Cp*), 2.04 (s, 6 H, Me, Xy),
3
2.53 (s, 3 H, Me), 3.82 (s, 3 H, Me), 7.04 (d, 2 H, CH, Xy, 3JHH
)
2.72 (m, 3 H, MeNH2), 2.97 (d, 3 H, Me8, JHH ) 4 Hz), 3.17 (d,
1 H, CH2, 2JHH ) 15 Hz), 3.56 (s, 3 H, Me4), 4.22 (br, 2 H, NH2),
the NH resonance is not observed. 13C{1H} APT NMR (75 MHz,
acetone-d6): Isomer A: δ 8.9 (Me, Cp*), 20.8 (Me6), 26.5 (Me5),
28.3 (Me7), 32.8 (NH2Me), 35.8 (Me8), 47.2 (Me4), 56.1 (C2),
56.2 (C3), 98.2 (d, C, Cp*, 1JCRh ) 7.8 Hz), 187.7 (C1). Isomer B:
δ 9.6 (Me, Cp*), 25.7 (Me7), 25.8 (Me5), 26.0 (Me6), 32.9
(NH2Me), 37.4 (Me8), 44.7 (Me4), 57.5 (C2), 58.8 (C3), 98.1 (d,
C, Cp*, 1JCRh ) 7.8 Hz), 187.8 (C1). IR (cm-1): νNH 3302, 3270,
3177; νCdN 1652, 1604. ΛM (Ω-1 cm2 mol-1): 245. Anal. Calcd
for C19H40Cl2N3O9Rh: C, 36.32; H, 6.42; N, 6.69. Found: C, 36.25;
H, 6.53; N, 6.69.
3
3
7 Hz), 7.17 (t, 1 H, CH, Xy, JHH ) 7 Hz), 7.22 (t, 1 H, CH, JHH
3
3
) 7 Hz), 7.32 (t, 1 H, CH, JHH ) 7 Hz), 7.54 (d, 1 H, CH, JHH
) 7 Hz), 7.58 (d, 1 H, CH, 3JHH ) 7 Hz). 13C{1H} APT NMR (75
MHz, CDCl3): δ 9.7 (Me, Cp*), 16.0 (CMe), 18.2 (Me, Xy), 46.4
(Me, NMe), 102.2 (d, C, Cp*, 1JCRh ) 8 Hz), 124.7 (CH, Ph), 128.2
(meta-C, Xy), 128.7 (CH, Ph), 129.7 (para-C, Xy), 131.7 (CH,
Ph), 134.9 (orto-C, Xy), 136.1 (CH, Ph), 146.9 (ipso-C, Ph), 173.2
1
(d, C-Rh, JCRh ) 30 Hz), 182.6 (CdN). IR (cm-1): νCtN 2146;
ν
CdN 1600.ΛM (Ω-1 cm2 mol-1): 163.Anal.CalcdforC29H34F3N2O3-
SRh: C, 53.54; H, 5.27; N, 4.31; S, 4.93. Found: C, 53.50; H,
5.52; N, 4.40; S, 4.86.
Synthesis of [Rh(Cp*){C,N-C6H4C(Me)dN(Me)-2}(NH2Me)]-
TfO (10a‚TfO). A suspension of 6‚TfO(234 mg, 0.37 mmol) in
acetophenone (3 mL) was heated at 80 °C for 4 h. The resulting
brownish suspension was filtered, and upon the addition of Et2O
(30 mL) to the filtrate, a suspension formed, which was filtered.
The yellow solid collected was washed with Et2O (3 × 10 mL)
and suction dried to give 10a‚TfO. Yield: 191 mg, 93%. mp: 133
°C. 1H NMR (300 MHz, CDCl3): δ 1.68 (s, 15 H, Me, Cp*), 2.03
Synthesis of [Rh(Cp*){C,N-C(dNXy)C6H4{C(Me)dNMe}-
2}(CNXy)]TfO‚2H2O (11‚TfO). A solution containing 10a‚TfO
(60 mg, 0.11 mmol) and XyNC (172 mg, 1.30 mmol) in CHCl3
(15 mL) was refluxed for 1 day and then filtered through a short
pad of Celite. The solution was concentrated under a vacuum (1
mL), and Et2O (30 mL) was added. The resulting suspension was
filtered, and the orange solid collected was washed with Et2O (3
× 10 mL) and suction dried to give 11‚TfO. Yield: 53 mg, 62%.
3
1
(t, 3 H, Me, JHH ) 6 Hz), 2.42 (s, 3 H, Me), 3.80 (s, 3 H, Me),
mp: 92 °C. H NMR (400 MHz, CDCl3): δ 1.55 (s, 3 H, Me,
3
3
7.14 (t, 1 H, CH, JHH ) 8 Hz), 7.28 (t, 1 H, CH, JHH ) 8 Hz),
Xy), 1.60 (s, 19 H, Me, Cp*, H2O), 2.34 (s, 3 H, Me, Xy), 2.36 (s,
6 H, Me, Xy), 2.79 (s, 3 H, Me), 3.95 (s, 3 H, Me), 6.54-7.85 (m,
10 H). 13C{1H} APT NMR (75 MHz, CDCl3) δ 9.1 (Me, Cp*),
18.51 (Me, Xy), 18.8 (Me, Xy), 18.9 (Me, Xy), 20.5 (CMe), 52.2
(NMe), 102.8 (d, C, Cp*, 1JCRh ) 5 Hz), 122.3 (CH), 122.7 (CH),
127.5 (CH), 127.8 (CH), 128.2 (CH), 128.6 (CH), 129.6 (CH), 130.1
(CH), 131.3 (CH), 131.1 (C), 135.3 (C), 150.0 (C). IR (cm-1): νCt
3
3
7.44 (d, 1 H, CH, JHH ) 8 Hz), 7.72 (d, 1 H, CH, JHH ) 8 Hz).
13C{1H} APT NMR (75 MHz, CDCl3): δ 9.1 (Me, Cp*), 15.3
(CMe), 32.4 (Me, MeNH2), 44.5 (NMe), 96.3 (d, CdC, Cp*, 1JCRh
) 8 Hz), 123.7 (CH, Ph), 127.8 (CH, Ph), 131.3 (CH, Ph), 135.2
1
(CH, Ph), 147.3 (ipso-C, Ph), 181.0 (d, C-Rh, JCRh ) 30 Hz),
181.8 (d, CdN, JCRh ) 2 Hz). IR (cm-1): νNH 3292, 3256; νCdN
2
1602. ΛM (Ω-1 cm2 mol-1): 140. Anal. Calcd for C21H30F3N2O3-
RhS: C, 45.82; H, 5.49; N, 5.09; S, 5.83. Found: C, 45.34; H,
5.64; N, 4.83; S, 6.04. MS (FAB+): (m/z, %) [M+] 401.2, 9.67;
[M+ - MeNH2] 370, 100. Crystals of 10a‚TfO suitable for an X-ray
diffraction study were obtained from CH2Cl2 and Et2O by the liquid
diffusion method.
2134; νCdN 1620. ΛM (Ω-1 cm2 mol-1): 126. Anal. Calcd for
N
C38H47N3F3O5RhS: C, 55.81; H, 5.79; N, 5.14; S, 3.92. Found:
C, 55.52; H, 5.30; N, 5.52; S, 3.79. MS (FAB+): (m/z, %) [M+]
632.2, 100; [M+ - XyNC] 501.0, 37.55; [M+ - 2 XyNC] 370, 54.95.
From the CH3Cl/Et2O mother liquor from which 11‚TfO precipi-
tated, orange crystals grew, which were submitted for an X-ray
diffraction study (below).
X-ray Structure Determinations. 9a‚ClO4‚acetone-d6, 9c‚ClO4
10a‚TfO, and 11‚TfO were measured on a Bruker Smart APEX
machine. Data were collected using monochromated Mo-KR
radiation in w scan mode. Crystal data and refinement details for
9a‚ClO4‚acetone-d6, 9c‚ClO4, and 10a‚TfO are presented in Table
Synthesis of [Rh(Cp*){C,N-C6H4{C(Me)dNMe}-2}(CNR)]-
t
TfO [R ) Bu (10b‚TfO), Xy (10c‚TfO)]. To a solution of 10a‚
TfO (150 mg, 0.27 mmol for 10b‚TfO; 300 mg, 0.55 mmol for
10c‚TfO) in CHCl3 (10b‚TfO: 20 mL) or CH2Cl2 (10c‚TfO: 20
mL) was added the isocyanide RNC (10b‚TfO: R ) tBu, 185 µL,
1.64 mmol; 10c‚TfO: R ) Xy, 107 mg, 0.82 mmol). The reaction
Inorganic Chemistry, Vol. 46, No. 21, 2007 8943

Vicente et al.
Table 1. Crystal Data and Structure Refinement
complex
9a·ClO4·acetone-d6
9c·ClO4
10a·TfO
formula
fw
temperature (K)
cryst syst
space group
a (Å)
b (Å)
c (Å)
R (deg)
â (deg)
γ (deg)
V (Å3)
C22H36D6Cl2N3O9Rh
678.40
293(2)
triclinic
P1h
10.3800(5)
11.1724(5)
13.4906(6)
68.798(2)
86.115(2)
82.602(2)
1446.08(11)
2
1.558
0.827
692
0.32 × 0.22 × 0.12
1.97-26.73
16 361
6080
0.0167
C27H42Cl2N3O8Rh
710.45
100(2)
monoclinic
P 2(1)/n
11.3390(5)
15.8885(6)
17.0075(7)
90
C21H30F3N2O3RhS
550.44
100(2)
orthorhombic
P bca
12.1899(5)
14.9406(6)
24.7220(10)
90
90
90
4502.5(3)
8
1.624
0.901
2256
0.15 × 0.10 × 0.05
1.65-28.27
49 809
5362
0.0580
96.140(2)
90
3046.5(2)
Z
F
4
calcd (Mg m-3
)
1.549
0.788
1472
0.30 × 0.12 × 0.05
1.76-26.37
33 093
6225
0.0394
µ (Mo KR)(mm-1
F(000)
)
cryst size (mm3)
θ range (deg)
no. of rflns coll
no. of indep rflns
Rint
max. and min. transmsn
restraints/params
GOF on F 2
0.9073 and 0.7779
0/359
1.080
0.0291
0.0719
0.943 and
-0.811
0.9617 and 0.7979
22/432
1.088
0.0336
0.0744
0.641 and
0.454
0.9563 and 0.8766
1/296
1.080
0.0367
0.0744
0.784 and
-0.606
R1 [I > 2σ(I)]
wR2 (all reflns)
largest diff. peak
and hole (e.Å-3
)
Scheme 1
1. The structure of 9a‚ClO4 was solved by direct methods and 9c‚
ClO4 and 10a‚TfO were solved by the heavy-atom method. All of
the non-hydrogen atoms were refined anisotropically on F 2
(program SHELX-97m, G. M. Sheldrick, Univerity of Go¨ttingen:
Go¨ttingen, Germany). Restraints to local aromatic ring symmetry
or light atom displacement factor components were applied in some
cases. Hydrogen atoms were refined as free (NH) or using a rigid
(Me) or a riding (all other hydrogens) model. Special features: In
9a‚ClO4, the oxygen atoms of one of the perchlorate anions are
disordered over two positions (ca. 80:20). In 9c‚ClO4, the amino-
imino ligand is disordered over two positions (ca. 70:30). The NH
hydrogen of the minority part was not included in the refinement.
The crystal structure of 11‚TfO was measured at -173 °C, but
because it contains (1) eight unit formulas per asymmetric unit,
(2) some solvent (Et2O) of crystallization, (3) some phenyl rings
and triflate anions disordered over two positions, and (4) a Rint )
0.1032, convergence was found to be very slow. Additionally, there
was also some residual electron density as a solitary peak. All these
reasons made it impossible to refine the structure properly. Different
crystals were measured, trying to get better data, but all of them
gave the same problems. The unit cell parameters are: monoclinic,
a ) 39.3716(19), b ) 30.1642(15), c ) 26.5919(13) Å, â ) 98.868-
(2)°, V ) 31203.36 (6) Å3, T ) 100(2) K, space group P2(1)/c, Z
) 32, 198 853 reflections measured, 70 422 unique (Rint ) 0.1032).
Results and Discussion
Synthesis of Ag+ and Rh(III) Methyl Amino Com-
plexes. The reaction of AgX with MeNH2 (1:2, Et2O)
produces almost quantitative precipitation of [Ag(NH2Me)2]X
[X ) TfO (1‚TfO), ClO4 (1‚ClO4); Scheme 1]. Two
homologous complexes with N(CF3SO2)2- 22 or [Cr(NCS)4-
(NH2Ph)2]- 23 counterions have been reported, and other salts
have been studied theoretically.24
Neutral mono(amino) Rh(III) complexes [Rh(Cp*)Cl2-
(22) Jing-Fang, H.; Huimin, H.; Sheng, D. J. Electrochem. Soc. 2006, 153,
j9.
(NH2R)] [R ) Me (2a), To (2b)] were prepared by reacting
8944 Inorganic Chemistry, Vol. 46, No. 21, 2007

Ortho-Rhodiated Acetophenone Methyl Imine Complexes
Scheme 2
[Rh(Cp*)Cl(µ-Cl)]2 with the stoichiometric amount of RNH2
(R ) Me, To ) C6H4Me-4, Scheme 1). The synthesis of 2b
was reported long ago,19 although no NMR data were
provided and it was said to be unstable in solution, which
we cannot corroborate.
Monocationic mono(amino) complex [Rh(Cp*)Cl(NH2-
Me)(PPh3)]TfO‚H2O (3‚TfO) was obtained by reacting
equimolar amounts of [Rh(Cp*)Cl2(PPh3)]19 and 1‚TfO in
CH2Cl2 (Scheme 1). The reaction of the same rhodium
complex with 1‚TfO (1:2, in CH2Cl2), intended to produce
[Rh(Cp*)(NH2Me)2(PPh3)](TfO)2, gave instead a mixture of
the expected product25 along with 3‚TfO and other species
that we could not separate and were shown by 31P NMR to
contain some [Ag+]PPh3 species.
The monocationic bis(amino) complexes [Rh(Cp*)Cl-
(NH2R)2]X [R ) Me, X ) Cl (4a‚Cl), ClO4 (4a‚ClO4), R
) C6H4Me-4 (To), X ) CF3SO3 (TfO) (4b‚TfO)] were
prepared, respectively, by reacting [Rh(Cp*)Cl(µ-Cl)]2 with
MeNH2 (1:4) in CH2Cl2, from 4a‚Cl and NaClO4‚H2O (1:
4.8) in THF, or by the one-pot reaction of [Rh(Cp*)Cl(µ-
Cl)]2, ToNH2 (To ) C6H4Me-4), and TlTfO (1:4:2) in
CH2Cl2. 4a‚Cl is insoluble in CH2Cl2 and was isolated
in almost quantitative yield by filtration of the reaction
mixture.
Dicationic mono(amino) complex [Rh(Cp*)(NH2Me)-
(tBubpy)](TfO)2 (5‚TfO) was prepared by reacting 2a with
TlTfO and tBubpy (1:2:1), and the dicationic tris(amino) [Rh-
(Cp*)(NH2Me)3](TfO)2 (6‚TfO) was obtained, in almost
quantitative yield, by reacting [Rh(Cp*)Cl(µ-Cl)]2 with 1‚
TfO (1:4). The reaction to prepare 6‚TfO from [Rh(Cp*)-
Cl(µ-Cl)]2, MeNH2, and XTfO (X ) Ag, Tl) (1:6:4, in
CH2Cl2) is not convenient because in this way it forms along
with 4a‚TfO. Additionally, massive decomposition took
place when AgTfO was used.
As mentioned in the Introduction, in spite of the many
known Rh(III) complexes with primary amine ligands, those
with MeNH2 are scarce, and only one organometallic
compound has been reported, without experimental details.
2-6 constitute the first family of methyl amino complexes
of rhodium. It includes neutral, mono-, and dicationic
complexes with 1 to 3 MeNH2 ligands. Silver complex 1 is
a key reagent in the synthesis of dicationic complex 6 and
could have application for the synthesis of other metal
complexes.
CMe2}2]X [X ) TfO (7‚TfO), ClO4 (7‚ClO4)] (Scheme 2).
In both complexes, the two Me groups bonded to carbon
give one quartet each. That at a lower δ value is not well
resolved, and we assign it to the Me group cis to the NMe
group, whereas the other, displaying a 5JHH coupling constant
of 1.2 Hz, is assigned to the CMe protons trans to NMe.
The expected quartet of quartets for NMe protons is observed
as a multiplet. The solutions of 7‚TfO are more stable in
acetone than in CHCl3, and both are more stable than those
of 7‚ClO4. We have always used them freshly prepared. The
reaction of 7‚TfO with [AuCl(PPh3)] (1:1, in acetone)
produced the previously reported complex [Au{N(Me)d
1
CMe2}(PPh3)]TfO3 in 82% yield which, along with the H
NMR spectra, offer sufficient evidence about the nature of
these oily compounds.
From the Rh(III) methyl amino complexes, we have
unfruitfully attempted the synthesis of the corresponding
imino complexes by reacting them with acetone under
different reaction conditions, as evidenced by the lack of
the resonance around 3.3-3.7 ppm expected for the CdNMe
protons in the reaction products. When reactions with acetone
at room temperature were attempted, the monoamino com-
plexes 2a (3 days), 3‚TfO (2h), and 5‚TfO (7h or 24 h
refluxing) were recovered unchanged irrespective their
charge, and 4a‚Cl (3 days) or 6‚TfO (5 h) gave mixtures of
species containing 2a or [Rh(Cp*)(Me-imam)(NH2Me)]-
(TfO)2 (9d‚ClO4, below), respectively. Refluxing 2a (1 day)
or 3‚TfO (2h) in acetone or by reacting [Rh(Cp*)Cl2(PPh3)]
with TlTfO and MeNH2 (1:2:2, 24 h) in acetone under N2,
afforded [Rh(Cp*)Cl(µ-Cl)]2 in the first case, or a complex
mixture, in the others.
Reactivity of Methyl Amino Complexes Toward
Acetone. Synthesis of [Ag{N(Me)dCMe2}2]+ and Me-
imam Rh(III) Complexes. Complexes 1 react with acetone
(1 h, at room temperature) to give solutions from which oily
1
materials are obtained. Their H NMR spectra show only
the three resonances expected for complexes [Ag{N(Me)d
(23) Mathur, P. K.; Srivastara, L. N. J. Inorg. Nucl. Chem. 1973, 35, 2112.
(24) El Aribi, H.; Rodr´ıguez, C. F.; Shoeib, T.; Y., L.; Hopkinson,
A. C.; Michel Siu, K. W. J. Phys. Chem. A 2002, 106, 8798. Widmer-
Cooper, A. N.; Lindoy, L. F.; Feimers, J. R. J. Phys. Chem. A 2001,
105, 6567.
Upon stirring an acetone solution of 4a‚ClO4 at room
temperature for 1 day or refluxing it for 2 h, the complex
[Rh(Cp*)Cl(Me-imam)]ClO4 (8‚ClO4) formed in 91% yield
(Scheme 2). The reaction is likely to occur through the
intermediate bis(imino) complex [Rh(Cp*)Cl{N(Me)d
CMe2}2]ClO4 that would be unstable toward the intramo-
4
(25) 1H NMR (400 MHz, dmso-d6): δ 1.62 (d, 15 H, Me, Cp*, JHP ) 2
Hz), 2.33 (t, 6 H, Me, 3JHH ) 6 Hz), 3.97 (br, 4 H, NH2), 7.37-7.59
(m, Ph, 30 H). 31P{1H} NMR (162 MHz, CDCl3): 33.53 (d, 1JP-Rh
142.8 Hz).
)
Inorganic Chemistry, Vol. 46, No. 21, 2007 8945

Vicente et al.
Scheme 3
lecular aldol-like condensation of its two imino ligands. This
intermediate, that we have not even detected after measuring
the NMR of the reaction mixture at different reaction times,
seems to be more reactive than its homologous with
6,7
acetimine [Rh(Cp*)Cl{NHdCMe2}2]ClO4 that could be
isolated and is stable in acetone solution for 24 h at room
temperature, although it also converts into the imino-amino
(“imam”) condensed product when it is refluxed in acetone
or treated with CO or with chloride or with catalytic amounts
of Ph2CdNH or SMe2 or with AsPh3 (1:1).
In conclusion, the reactions of neutral, mono, or dicationic
[Rh(III)]NH2Me complexes with acetone did not allow us
to isolate any [Rh(III)]N(Me)dCMe2 species. It seems that
the expected complexes are unstable and either decompose
to give unidentified species or hydrolyze back to the amino
starting complexes or undergo an aldol-like condensation
process to give “Me-imam” derivatives.
Attempts to Prepare Methyl Acetimino Complexes
through Transmetalation Reactions. We have prepared
different imino complexes through transmetalation reac-
tions.3,7 However, the analogous reactions of [Rh(Cp*)Cl-
(µ-Cl)]2, (1) with [Au{N(Me))CMe2}(PPh3)]TfO (1:2, in
dry acetone, under N2 or in the air) led to mixtures containing
[AuCl(PPh3)] and, among other species, 8‚TfO (reaction
under N2) or 2a (reaction in the air), (2) with 7‚TfO (1:4, in
dry acetone, N2) gave a mixture of both diastereoisomers of
[Rh(Cp*)(Me-imam)(NH2Me)](TfO)2 (9d‚TfO, below) plus
a small amount of 8‚TfO, or (3) with [Rh(Cp*)Cl(tBubpy)]-
TfO with 7‚TfO (1:1, in dry acetone, N2), afforded a 1:1
(Me-imam)L](ClO4)2 [L ) XyNC (9c‚ClO4), NH2Me (9d‚
ClO4)]. One of the diastereoisomers of 9c‚ClO4 is
insoluble in acetone, whereas the other is partially soluble,
which allowed us to isolate the first one in 58% yield by
washing the mixture with a small volume of acetone. The
1H NMR spectrum of 9d‚ClO4 in acetone-d6 (300 MHz)
shows the presence of two diastereoisomers in a 3:1 molar
ratio.
We have also failed to prepare complex [Rh(Cp*)(Me-
imam){N(Me)dCMe2}](ClO4)2 by reacting 9d‚ClO4 with
NH2Me in dry acetone (15 h, under nitrogen). We have
attempted to isolate the free Me-imam ligand by dis-
placing it from 8‚ClO4, but it does not react with NH2(CH2)2-
NH2 or with Ph2P(CH2)2PPh2 under different reaction condi-
tions.
1
mixture (by H NMR) of the desired complex [Rh(Cp*)-
26
{N(Me)dCMe2}(tBubpy)](TfO)2 and 5‚TfO, which con-
verted into pure 5‚TfO after recrystallization from acetone/
Et2O. Again, all these reactions strongly suggest that the
[Rh(Cp*)]-NMedCMe2 complexes are unstable and decom-
pose through aldol-like condensation or hydrolysis.
Synthesis of Acetophenone Methyl Imino Complexes.
When suspensions of 2a or 4a‚Cl in MeC(O)Ph were stirred
at room temperature or refluxed, formation of [Rh(Cp*)Cl-
(µ-Cl)]2 was observed. When 6‚TfO was stirred at room
temperature with MeC(O)Ph (1:6) in THF or in net ac-
etophenone for 2 or 24 h, respectively, it was recovered
unchanged. However, when a solution of 6‚TfO was heated
in a small volume of MeC(O)Ph at 80 °C for 4 h, the
orthometalated complex [Rh(Cp*){C,N-C6H4{C(Me)d
N(Me)}-2}(NH2Me)]TfO (10a‚TfO) formed along with
[MeNH3]TfO (Scheme 4). No complex of any metal with
this ligand has been reported so far, in spite of the existence
of a large number of complexes derived from the ortho-
metalation of arylimino ligands, many of them structurally
characterized by X-ray crystallography.27
We have also unfruitfully attempted to prepare complexes
containing a mixed-imam ligand resulting from the aldol
condensation of HNdCMe2 and MeNdCMe2 by reacting
6
in acetone, under N2 (1) [Rh(Cp*)Cl(NHdCMe2)2]ClO4
with 7‚ClO4 (1:1, 2 h), (2) [Rh(Cp*)(µ-Cl)(NHdCMe2)]2-
6
(ClO4)2 with MeNH2 (1:1, 5 h), (3) 3‚TfO and [Ag(NHd
CMe2)2]ClO4 (1:1, 1 h), and (4) 2a with [Ag(NHdCMe2)2]-
ClO4 (1:1, 1 h). The latter reaction gave a mixture of 4a‚
ClO4 and [Rh(Cp*)Cl(NHdCMe2)2]ClO4 (by NMR), which
converted into [Rh(Cp*)Cl(Me-imam)]ClO4 (8‚ClO4) and
[Rh(Cp*)Cl(imam)]ClO4 when the stirring was prolonged
for 3 days.
Reactivity of Rh(III) imam and Me-imam Complexes.
8‚ClO4 reacts with AgClO4 (1:1) in acetonitrile to give the
dicationic complex [Rh(Cp*)(Me-imam)(NCMe)](ClO4)2
(9b‚ClO4) in 92% yield (Scheme 3). The reaction of 9b‚
ClO4 with XyNC or with MeNH2 (1:1, in acetone for 2 h or
CH2Cl2 for 1 h, respectively; Xy ) C6H3Me2-1,6) produces
the replacement of the labile MeCN ligand to give [Rh(Cp*)-
t
The result of the reaction of 10a‚TfO with BuNC or
XyNC in refluxing CHCl3 depends on the isocyanide. Thus,
inthecaseoftBuNCcomplex[Rh(Cp*){C,N-C6H4{C(Me))N-
(Me)}-2}(CNtBu)]TfO (10b‚TfO) was the only species
isolated, even if a large excess of isocyanide was used and
the refluxing was prolonged for several days. However, in
(26) 1H NMR (300 MHz, acetone-d6): δ 1.44 (s, 18 H, Me, tBu), 1.80 (s,
15 H, Me, Cp*), 2.16 (s, Me), 2.38 (m, Me), 3.35 (s, N-Me), 8.10
3
4
4
(dd, 2 H, H5, JHH ) 6 Hz, JHH ) 2 Hz), 8.73 (d, 2 H, H3, JHH
)
(27) Cambridge Structural Database, version 5.27, Cambridge Crystal-
lographic Data Center: Cambridge, U.K., August, 2006.
3
2 Hz), 9.37 (d, 2 H, H6, JHH ) 6 Hz).
8946 Inorganic Chemistry, Vol. 46, No. 21, 2007

Ortho-Rhodiated Acetophenone Methyl Imine Complexes
Figure 2. Ellipsoid representation of the cation of 9c‚ClO4 (50%
probability). Selected bond lengths (Å) and angles (°): Rh(1)-N(1) )
2.191(8), Rh(1)-N(2) ) 2.110(11), Rh(1)-C(1) ) 2.211(2), Rh(1)-C(2)
) 2.165(2), Rh(1)-C(3) ) 2.180(2), Rh(1)-C(4) ) 2.203(2), Rh(1)-C(5)
) 2.195(2), Rh(1)-C(19) ) 1.992(3), N(1)-C(11) ) 1.498(9), N(1)-C(14)
) 1.510(8), N(2)-C(13) ) 1.275(10), N(2)-C(18) ) 1.451(10), N(3)-
C(19) ) 1.152(3), C(19)-Rh(1)-N(2) ) 91.3(4), N(2)-Rh(1)-N(1) )
89.8(3), N(1)-C(11)-C(12) ) 106.2(4), N(2)-C(13)-C(12) ) 120.9(6),
N(3)-C(19)-Rh(1) ) 170.3(2).
Figure 1. Ellipsoid representation of the cation of 9a‚ClO4 (50%
probability). Selected bond lengths (Å) and angles (°): Rh(1)-N(2) )
2.0771(19), Rh(1)-N(1) ) 2.1082(18), Rh(1)-N(3) ) 2.1571(19), Rh-
(1)-C(1) ) 2.170(2), Rh(1)-C(2) ) 2.160(2), Rh(1)-C(3) ) 2.174(2),
Rh(1)-C(4) ) 2.177(2), Rh(1)-C(5) ) 2.155(2), N(1)-C(17) ) 1.279-
(3), N(2)-C(11) ) 1.278(3), N(3)-C(13) ) 1.496(3), N(2)-Rh(1)-N(1)
) 90.73(7), N(2)-Rh(1)-N(3) ) 88.06(7), N(1)-Rh(1)-N(3) ) 85.06-
(7), C(17)-N(1)-Rh(1) ) 136.25(16), C(11)-N(2)-Rh(1) ) 130.99(16),
C(13)-N(3)-Rh(1) ) 121.91(14).
Scheme 4
Figure 3. Ellipsoid representation of the cation of 10a‚TfO (50%
probability). Selected bond lengths (Å) and angles (°): Rh(1)-C(1) ) 2.026-
(2), Rh(1)-N(1) ) 2.086(2), Rh(1)-N(2) ) 2.139(2), Rh(1)-C(11) )
2.252(2), Rh(1)-C(12) ) 2.153(2), Rh(1)-C(13) ) 2.177(2), Rh(1)-C(14)
) 2.165(2), Rh(1)-C(15) ) 2.263(2), N(1)-C(7) ) 1.294(3), N(2)-C(10)
) 1.477(3), C(1)-Rh(1)-N(1) ) 78.26(9), C(1)-Rh(1)-N(2) ) 87.11-
(9), N(1)-Rh(1)-N(2) ) 91.48(8), C(7)-N(1)-C(9) ) 122.4(2), C(7)-
N(1)-Rh(1) ) 117.35(17), C(9)-N(1)-Rh(1) ) 120.25(16), C(10)-N(2)-
Rh(1) ) 119.38(16).
the case of XyNC, the reaction produced the homologous
complex [Rh(Cp*){C,N-C6H4{C(Me)dN(Me)}-2}(CNXy)]
(10c‚TfO) when a 1:1.5 molar ratio of the reagents was used
and the reaction mixture was refluxed for 3 days, but when
a larger excess of XyNC (1:12) was used, complex [Rh-
(Cp*){C,N-C(dNXy)C6H4{C(Me)dN(Me)}-2}(CNXy)]-
TfO (11‚TfO) formed after 1 day of heating. Thus, XyNC,
apart from replacing the MeNH2 ligand, is also capable of
inserting into the Rh-C bond to give an iminoacyl fragment
and, consequently, an imino(iminoacyl) complex. As far as
we are aware, only one previous insertion of isocyanide into
a Rh(III)-Caryl bond has been reported.28
presented in Table 1. In all cases, the cations exhibit a
pseudo-octahedral three-leged piano-stool geometry, with the
Cp* group occupying three fac coordination sites. The Rh-
N(amino) [9a‚ClO4: 2.1571(19), 9c‚ClO4: 2.07(3), 10a‚
TfO: 2.139(2) Å], Rh-N(imino) [9a‚ClO4: 2.077(1),
2.1082(18), 9c‚ClO4: 2.110(11), 10a‚TfO: 2.026(2) Å] and
CdN [9a‚ClO4: 1.279(3), 1.278(3), 9c‚ClO4: 1.275(10),
10a‚TfO: 1.294(3) Å] bond distances are in the ranges found
for other Cp*-Rh(III) complexes (2.016-2.214, 2.067-
2.182, and 1.148-1.384 Å, respectively).27 The C-Rh-N
[9c‚ClO4: 91.3(4), 92.5(2), 10a‚TfO: 78.26(9), 87.11(9)°]
and N-Rh-N [9a‚ClO4: 90.73(7), 85.06(7), 88.06(7), 9c‚
ClO4: 89.8(3), 10a‚TfO: 91.48(8)°] angles are all close to
X-ray Crystal Structures. The crystal structures of 9a‚
ClO4‚acetone-d6 (Figure 1), 9c‚ClO4 (Figure 2), and 10a‚
TfO (Figure 3) have been determined. Numerical details are
(28) Jones, W. D.; Feher, F. J. Organometallics 1983, 2, 686.
Inorganic Chemistry, Vol. 46, No. 21, 2007 8947

Vicente et al.
Table 2. Hydrogen Bonds [Angstroms and Degrees] in
9a‚ClO4‚acetone-d6, 9c‚ClO4, and 10a‚TfOa
D-H‚‚‚A
d(D-H) d(H...A)
d(D...A)
<(DHA)
9a·ClO4·acetone-d6
10a·TfO
N(1)-H(01)‚‚‚Cl(2)#1
0.82(3)
2.98(3)
2.90(3)
2.25(3)
2.55
3.7721(19) 165(2)
N(3)-H(03B)‚‚‚Cl(2)#1 0.87(3)
3.726(2)
3.003(3)
3.462(4)
3.365(3)
3.296(3)
3.366(3)
160(2)
155(3)
157.9
139.4
145.5
167.7
N(2)-H(02)‚‚‚O(3)#2
C(7)-H(7B)‚‚‚O(3)#2
0.81(3)
0.96
C(19)-H(19C)‚‚‚O(2)#3 0.96
2.58
2.46
2.42
C(8)-H(8C)‚‚‚O(4)
0.96
0.96
C(99)-H(99B)‚‚‚O(2)
9c·ClO4
C(25)-H(25)‚‚‚O(8)#1
C(7)-H(7A)‚‚‚O(1)#2
0.95
0.98
2.53
2.57
3.375(4)
3.452(3)
147.5
149.2
10a·TfO
N(2)-H(0A)‚‚‚O(3)#1
N(2)-H(0B)‚‚‚O(1)#2
C(9)-H(9B)‚‚‚O(3)#2
0.85(2)
0.84(2)
0.98
2.25(2)
2.26(2)
2.50
3.055(3)
3.058(3)
3.452(3)
3.467(3)
159(3)
157(3)
163.9
151.4
C(20)-H(20B)‚‚‚O(1)#3 0.98
2.57
a Symmetry transformations used to generate equivalent atoms:
9a‚ClO4‚acetone-d6: #1 x, y - 1, z #2 x + 1, y, z #3 -x + 1, -y + 1,-z.
9c‚ClO4:#1 -x, -y, -z + 1 #2 -x + 1/2, y - 1/2, -z + 3/2. 10a‚TfO: #1
Figure 5. Hydrogen bonds in 10a‚TfO.
3
1
1
3
1
1
-x + /2, y - /2, z #2 -x + 1, y - /2, -z + /2 #3 -x + /2, y - /2, z.
Figure 6. The cation of 11‚TfO showing the connectivity pattern.
from a Xy-Me group, participate in CH‚‚‚O hydrogen bonds
to two different ClO4 anions. In 10a‚TfO (Figure 5), the
cations and the triflate anions are associated through two
hydrogen bonds (C9-H9B‚‚‚O1 and N2-H0B‚‚‚O1). Ad-
ditionally, the N2-H0A‚‚‚O3 and C20-H20B‚‚‚O1 hydro-
gen bonds link these aggregates, forming ribbons parallel to
the a axis.
Figure 4. View of some of the hydrogen bonds in 9a‚ClO4.
those expected for an octahedral disposition, with the
exception of the C(1)-Rh(1)-N(1) angle in 10a‚TfO, which
is narrow [78.26(9)°], likely imposed by the five-membered
metallacycle of which they form a part. The Cp*-Rh
moieties do not display special features.
The three crystal structures display various hydrogen
bonds, for which distances and angles are shown in Table
2. In 9a‚ClO4‚acetone-d6, the N-H‚‚‚Cl, N-H‚‚‚O, and
C-H‚‚‚O hydrogen bonds involve NH (acetimine), CH (Me,
from Cp* or from the acetone molecule), and ClO4 groups.
One perchlorate is linked to three different cations through
four hydrogen bonds (Figure 4). With two of them (C8-
H8C‚‚‚O4 and C19-H19C‚‚‚O2), two cations and two
anions generate macrocycles, which are extended with the
other hydrogen bonds to form a 3D network. In 9c‚ClO4,
two C-H bonds, one from a Cp*-Me and the other
As stated above, the structure of 11‚TfO could not be
refined because of the data quality, but the connectivity of
the cation could be established unambiguously (Figure 6).
NMR Spectra. The NMR spectra of all of the complexes
have been measured. 11‚TfO decomposes slowly in solution
1
and, although its H NMR spectrum is that of the pure
compound, the 13C shows some decomposition impurities,
making the assignment of some resonances difficult. In all
of the cases, the Cp* resonances appear in the 1.13-1.88
(Me protons), 8.0-9.5 (Me carbons), and 93.3-103.3
(quaternary carbons) ppm ranges. The later resonance is
usually a doublet with JCRh values of 5 to 9 Hz, although in
3‚TfO, it appears as a doublet of doublets because of
additional coupling to 31P (2JCP ) 3 Hz), whereas in
8948 Inorganic Chemistry, Vol. 46, No. 21, 2007

Ortho-Rhodiated Acetophenone Methyl Imine Complexes
9b‚ClO4, it is a broad singlet. In complexes with MeNH2
ligands (1-6 and 10a‚TfO), the Me protons give a singlet
(1) or a triplet in the 2.03-2.64 ppm region, with 3JHH values
of some 6 Hz; the NH2 protons give a broad resonance
between 3.01 and 4.70 ppm except in 10a‚TfO (two singlets),
and the Me carbons appear in the 30.9-32.5 ppm range.
bands. 9b‚ClO4 displays a very broad absorption that we
assume to include two νNH bands. For complexes 8‚ClO4
and 9b‚ClO4, the νNH bands along with two νCdN bands (Me-
imam ligand: 1650-1708 cm-1) and additionally, in 9b‚
ClO4, two νCtN bands due to the MeCN ligand at 2136 and
2288 cm-1, suggest the presence or both possible diastere-
oisomers of these complexes in the solid state. Correspond-
ingly, the isolated isomer of its homologous 9c‚ClO4 shows
only one band of each type in its spectrum.
Me-imam complexes 8 and 9b-d bear two chiral centers.
Their NMR spectra show, at room temperature for 8‚ClO4,
9c‚ClO4, and 9d‚ClO4, or at -80 °C for 9b‚ClO4, the
resonances of the two expected diastereoisomers, suggesting
that in the later, a fast interconversion process takes place
at room temperature, probably through dissociation of MeCN.
In complex 8‚ClO4, we have observed that the relative
proportion of both diastereoisomers depends on the solvent.
Thus, in CDCl3, they are in a 1:1 molar ratio, whereas in
acetone-d6 and in dmso-d6, one of them transforms into the
other, the difference of concentration being greater in dmso-
d6 (3:1) than in acetone (1.25:1). It is reasonable to assume
that this isomerization is catalyzed by the solvent through
the formation of the dicationic intermediate [Rh(Cp*)(Me-
imam)(S)]Cl(ClO4) (S ) acetone, dmso). The resonances of
the Me-imam ligand in 8 and 9 have been fully assigned by
means of HMQC and HMBC correlation experiments
(Experimental Section and Chart 1). All of these complexes
show (1) the Me protons and carbon nuclei on the iminic
nitrogen less shielded (Me4: 3.5-3.98 and 45.5-49.7 ppm,
respectively) than those on the aminic nitrogen (Me8: 2.65-
2.73 and 34.9-37.3 ppm, respectively); (2) the NdC carbon
nuclei (C1:182.9-187.6 ppm) less shielded than the NH-C
ones (C3: 53.3-57.1 ppm); (3) the inequivalent methylene
protons as two doublets in the 1.99-2.70 and 2.92-2.98
ppm regions with the exception of one isomer of 8‚ClO4
that unexpectedly shows this resonance as a singlet at 2.51
ppm; and (4) the NH proton in the 4.2-5.3 ppm region.
In the NMR spectra of 10‚TfO, the resonances due to the
NMe groups are deshielded (1H: 3.74-3.82, 13C: 44.5-
46.4 ppm) with respect to the CMe ones (1H: 2.42-2.53,
13C: 15.3-16.0 ppm). The XyNC ligand in 10c‚TfO is free
to rotate about the Rh-C or Xy-N bond, giving rise to a
single resonance for both Me groups (1H: 2.04; 13C: 18.2
ppm). In the 1H NMR spectrum of 11‚TfO, the same trends
are observed for the NMe, CMe (at 3.95 and 2.79 ppm,
respectively), and Me protons of the XyNC ligand. However,
one of the Xy groups shows two inequivalent Me groups
due to its prevented rotation around the Xy-N bond, owing
to its proximity to the Cp* ligand, if it is that of the XyNC
ligand, or to the aryl group, if it is that of the iminoacyl
group. We have also observed this behavior in some Xy
iminoacyl palladium(II) complexes.29
Conclusion
We have isolated and characterized the first family of
methyl amino complexes of rhodium, which includes neutral,
mono-, and dicationic complexes with 1 to 3 MeNH2 ligands,
and the silver complex [Ag(NH2Me)2]+, which is a key
reagent in the synthesis of the dicationic complex [Rh(Cp*)-
(NH2Me)3](TfO)2. We report the synthesis of [Ag{N(Me)d
CMe2}2]ClO4 and its use to prepare [Au{N(Me)dCMe2}-
(PPh3)]ClO4. Both are some of the few known methyl
acetimino metal complexes. However, many attempts to
prepare complexes [Rh(III)]N(Me)dCMe2 by condensation
of acetone with complexes [Rh(III)]NH2Me or by transmeta-
latation using [Au{N(Me)dCMe2}(PPh3)]ClO4 or [Ag-
{N(Me)dCMe2}2]ClO4 and different Rh(III) complexes gave
instead complexes [Rh(III)]NH2Me or [Rh(III)](Me-imam)
(Me-imam ) N,N′-N(Me)dC(Me)CH2C(Me)2NHMe. The
latter are the result of the aldol condensation of the non-
isolated [Rh(III)]{N(Me)dCMe2}2 complexes. The only [Rh-
(III)](Me-imam) complex isolated and characterized from
these reactions has been [Rh(Cp*)Cl(Me-imam)]ClO4, from
which dicationic [Rh(Cp*)(Me-imam)L](ClO4)2 have been
prepared. Acetophenone reacts with [Rh(Cp*)(NH2Me)3]-
(TfO)2 to give [Rh(Cp*){C,N-C6H4{C(Me)dN(Me)}-2}-
(NH2Me)]TfO, which is the first product of such a conden-
sation and cyclometalation reaction, from which an
adduct and an insertion product with XyNC have been
prepared.
Acknowledgment. We thank Direccio´n General de In-
vestigacio´n, Ministerio de Educacio´n y Ciencia, and FEDER
for financial support (Grant CTQ2004-05396) and for a
contract to I.V.H.
Supporting Information Available: CIF files for 9a‚ClO4‚
acetone-d6, 9c‚ClO4, and 10a‚TfO. This material is available free
of charge via the Internet at http://pubs.acs.org.
IC700963H
(29) Vicente, J.; Abad, J. A.; Fo¨rtsch, W.; Jones, P. G.; Fischer, A. K.
Organometallics 2001, 20, 2704. Vicente, J.; Abad, J. A.; Herna´ndez-
Mata, F. S.; Rink, B.; Jones, P. G.; Ram´ırez de Arellano, M. C.
Organometallics 2004, 23, 1292. Vicente, J.; Abad, J. A.; Lo´pez-Sa´ez,
M. J.; Fo¨rtsch, W.; Jones, P. G. Organometallics 2004, 23, 4414.
Vicente, J.; Abad, J. A.; Mart´ınez-Viviente, E.; Jones, P. G. Orga-
nometallics 2002, 21, 4454.
IR Spectra. In the 3100-3326 cm-1 region, the IR show
one (9c‚ClO4), two (8‚ClO4, 10a‚TfO), three (1, 5‚TfO, 3,
4a‚ClO4, 4b‚TfO, 9a‚ClO4, 9d‚ClO4), or four (4a‚Cl) νNH
Inorganic Chemistry, Vol. 46, No. 21, 2007 8949