Synthesis and reactivity of Ir(I) and Ir(III) complexes with MeNH 2, Me2C=NR (R = H, Me), C,N-C6H 4{C(Me)=N(Me)}-2, and N,N′-RN=C(Me)CH2C(Me 2)NHR (R = H, Me) ligands

Article abstract of DOI:10.1021/ic801184v

Complexes [Ir(Cp*)Cl_n(NH₂Me) _3-n]X_m (n = 2, m = 0 (1), n = 1, m = 1, X = Cl (2a), n = 0, m = 2, X = OTf (3)) are obtained by reacting [Ir(Cp*)Cl(μ-Cl)] ₂ with MeNH₂ (1:2 or 1:8) or with [Ag(NH ₂Me)₂]OTf (1:4), respectively. Complex 2b (n = 1, m = 1, X = ClO₄) is obtained from 2a and NaClO₄·H ₂O. The reaction of 3 with MeC(O)Ph at 80°C gives [Ir(Cp*){C,N-C₆H₄{C(Me)=N(Me)}-2}(NH ₂Me)]OTf (4), which in turn reacts with RNC to give [Ir(Cp*){C,N-C₆H₄{C(Me)=N(Me)}-2}(CNR)]OTf (R = ^tBu (5), Xy (6)). [Ir(μ-Cl)(COD)]₂ reacts with [Ag{N(R)=CMe₂}₂]X (1:2) to give [Ir{N(R)=CMe ₂}₂(COD)]X (R = H, X = ClO₄ (7); R = Me, X = OTf (8)). Complexes [Ir(CO)₂(NH=CMe₂)₂]ClO ₄ (9) and [IrCl{N(R)=CMe₂}(COD)] (R = H (10), Me (11)) are obtained from the appropriate [Ir{N(R)=CMe₂}₂(COD)]X and CO or Me₄NCl, respectively. [Ir(Cp*)Cl(μ-Cl)]₂ reacts with [Au(NH=CMe₂)(PPh₃)ClO₄ (1:2) to give [Ir(Cp*)(μ-Cl)(NH=CMe₂)]₂(ClO ₄)₂ (12) which in turn reacts with PPh₃ or Me₄NCl (1:2) to give [Ir(Cp*)Cl(NH=CMe₂)(PPh ₃)]ClO₄ (13) or [Ir(Cp*)Cl₂(NH=CMe ₂)] (14), respectively. Complex 14 hydrolyzes in a CH ₂Cl₂/Et₂O solution to give [Ir(Cp*) Cl₂(NH₃)] (15). The reaction of [Ir(Cp*)Cl(μ-Cl)] ₂ with [Ag(NH=CMe₂)2]ClO₄ (1:4) gives [Ir(Cp*)(NH=CMe₂)₃](ClO₄)₂ (16a), which reacts with PPNCl (PPN = Ph₃P=N=PPh₃) under different reaction conditions to give [Ir(Cp*)(NH=CMe₂) ₃]XY (X = Cl, Y = ClO₄ (16b); X = Y = Cl (16c)). Equimolar amounts of 14 and 16a react to give [Ir(Cp*)Cl(NH=CMe₂) ₂]ClO₄ (17), which in turn reacts with PPNCl to give [Ir(Cp*)Cl(H-imam)]Cl (R-imam = N,N′-N(R)=C(Me)CH ₂C(Me)₂NHR (18a)]. Complexes [Ir(Cp*)Cl(R-imam)] ClO₄ (R = H (18b), Me (19)) are obtained from 18a and AgClO ₄ or by refluxing 2b in acetone for 7 h, respectively. They react with AgClO₄ and the appropriate neutral ligand or with [Ag(NH=CMe₂)₂]ClO₄ to give [Ir(Cp*)(R- imam)L](ClO₄)₂ (R = H, L = ^tBuNC (20), XyNC (21); R = Me, L = MeCN (22)) or [Ir(Cp*)(H-imam)(NH=CMe ₂)](ClO₄)₂ (23a), respectively. The later reacts with PPNCl to give [Ir(Cp*)(H-imam)(NH=CMe₂)]Cl(ClO ₄) (23b). The reaction of 22 with XyNC gives [Ir(Cp*)(Me-imam) (CNXy)](ClO₄)₂ (24). The structures of complexes 15, 16c and 18b have been solved by X-ray diffraction methods.

Full text of DOI:10.1021/ic801184v

Inorg. Chem. 2008, 47, 9592-9605
Synthesis and Reactivity of Ir(I) and Ir(III) Complexes with MeNH2,
Me2CdNR (R ) H, Me), C,N-C6H4{C(Me)dN(Me)}-2, and
N,N′-RNdC(Me)CH2C(Me2)NHR (R ) H, Me) Ligands
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, Facultad de Qu´ımica,
UniVersidad de Murcia, Aptdo. 4021, 30071 Murcia, Spain, and UniVersidad de Murcia, SAI,
Aptdo. 4021, 30071 Murcia, Spain
Received June 26, 2008
Complexes [Ir(Cp*)Cln(NH2Me)3-n]Xm (n ) 2, m ) 0 (1), n ) 1, m ) 1, X ) Cl (2a), n ) 0, m ) 2, X ) OTf
(3)) are obtained by reacting [Ir(Cp*)Cl(µ-Cl)]2 with MeNH2 (1:2 or 1:8) or with [Ag(NH2Me)2]OTf (1:4), respectively.
Complex 2b (n ) 1, m ) 1, X ) ClO4) is obtained from 2a and NaClO4 ·H2O. The reaction of 3 with MeC(O)Ph
at 80 °C gives [Ir(Cp*){C,N-C6H4{C(Me)dN(Me)}-2}(NH2Me)]OTf (4), which in turn reacts with RNC to give [Ir(Cp*){C,N-
t
C6H4{C(Me)dN(Me)}-2}(CNR)]OTf (R ) Bu (5), Xy (6)). [Ir(µ-Cl)(COD)]2 reacts with [Ag{N(R)dCMe2}2]X (1:2) to
give [Ir{N(R)dCMe2}2(COD)]X (R ) H, X ) ClO4 (7); R ) Me, X ) OTf (8)). Complexes [Ir(CO)2(NHdCMe2)2]ClO4
(9) and [IrCl{N(R)dCMe2}(COD)] (R ) H (10), Me (11)) are obtained from the appropriate [Ir{N(R)dCMe2}2(COD)]X
and CO or Me4NCl, respectively. [Ir(Cp*)Cl(µ-Cl)]2 reacts with [Au(NHdCMe2)(PPh3)]ClO4 (1:2) to give [Ir(Cp*)(µ-
Cl)(NHdCMe2)]2(ClO4)2 (12) which in turn reacts with PPh3 or Me4NCl (1:2) to give [Ir(Cp*)Cl(NHdCMe2)(PPh3)]ClO4
(13) or [Ir(Cp*)Cl2(NHdCMe2)] (14), respectively. Complex 14 hydrolyzes in a CH2Cl2/Et2O solution to give
[Ir(Cp*)Cl2(NH3)] (15). The reaction of [Ir(Cp*)Cl(µ-Cl)]2 with [Ag(NHdCMe2)2]ClO4 (1:4) gives [Ir(Cp*)(NHd
CMe2)3](ClO4)2 (16a), which reacts with PPNCl (PPN ) Ph3PdNdPPh3) under different reaction conditions to
give [Ir(Cp*)(NHdCMe2)3]XY (X ) Cl, Y ) ClO4 (16b); X ) Y ) Cl (16c)). Equimolar amounts of 14 and 16a
react to give [Ir(Cp*)Cl(NHdCMe2)2]ClO4 (17), which in turn reacts with PPNCl to give [Ir(Cp*)Cl(H-imam)]Cl (R-
imam ) N,N′-N(R)dC(Me)CH2C(Me)2NHR (18a)]. Complexes [Ir(Cp*)Cl(R-imam)]ClO4 (R ) H (18b), Me (19))
are obtained from 18a and AgClO4 or by refluxing 2b in acetone for 7 h, respectively. They react with AgClO4 and
t
the appropriate neutral ligand or with [Ag(NHdCMe2)2]ClO4 to give [Ir(Cp*)(R-imam)L](ClO4)2 (R ) H, L ) BuNC
(20), XyNC (21); R ) Me, L ) MeCN (22)) or [Ir(Cp*)(H-imam)(NHdCMe2)](ClO4)2 (23a), respectively. The later
reacts with PPNCl to give [Ir(Cp*)(H-imam)(NHdCMe2)]Cl(ClO4) (23b). The reaction of 22 with XyNC gives [Ir(Cp*)(Me-
imam)(CNXy)](ClO4)2 (24). The structures of complexes 15, 16c and 18b have been solved by X-ray diffraction
methods.
Introduction
ammonia mixtures or from R-aminonitriles it is rather
unstable and decomposes quickly on storage (even at 0 °C)
to give acetonine (2,2,4,4,6-pentamethyl-2,3,4,5-tetrahydro-
pyrimidine) with ammonia loss.2 In turn, N-methyl substi-
Our interest in the study of metal imino complexes is
mainly based on the fact that imines participate in many
interesting chemical transformations including carbon-carbon
bond formation and ring construction processes.1 In particu-
lar, although acetimine can be obtained from acetone/
(1) (a) Robertson, G. M. ComprehensiVe Organic Functional Group
Transformations; Robertson, G. M., Ed.; Pergamon: Oxford, U.K.,
1995; Vol. 3. (b) Yamago, S.; Miyazoe, H.; Nakayama, T.; Miyoshi,
M.; Yoshida, J. Angew. Chem., Int. Ed. 2003, 42, 117. (c) Kaluza, Z.;
Mostowicz, D.; Dolega, G.; Mroczko, K.; Wojcik, R. Tetrahedron
2006, 62, 943. (d) Noguchi, M.; Matsumoto, S.; Shirai, M.; Yamamoto,
H. Tetrahedron 2003, 59, 4123. (e) Zhang, G.; Huang, X.; G., L.;
Hang, L. J. Am. Chem. Soc. 2008, 130, 1814.
* To whom correspondence regarding the synthesis and properties of
complexes should be addressed. E-mail: mch@um.es (M.T.C.), jvs1@
um.es (J.V.).
†
Grupo de Qu´ımica Organometálica.
‡ SAI. To whom correspondence regarding the X-ray diffraction studies
should be addressed. E-mail: dbc@um.es.
(2) Findeisen, K.; Heitzer, H.; Dehnicke, K. Synthesis 1981, 702.
9592 Inorganic Chemistry, Vol. 47, No. 20, 2008
10.1021/ic801184v CCC: $40.75  2008 American Chemical Society
Published on Web 09/23/2008

Synthesis and ReactiWity of Ir(I) and Ir(III) Complexes
Chart 1
tuted imines RR′CdNMe are very difficult to prepare from
azides,3,4 silazanes or silyl amines,5 N-chloroalkylamines or
R-aminonitrile6 and tend to polymerize.4 The difficulties in
preparing and handling these imines Me2CdNR (R ) H,
Me) must be associated with the scarcity of their metal
complexes which have been obtained through a variety of
methods none of them using the free ligands or being of
general application. Therefore, the synthesis of [M]-N(R)d
CMe2 complexes offers an effective means for studying the
properties of these ligands. A different type of NH-imines,
R(R′O)CdNH, R(R′NH)CdNH, and R{R′C(O)(Ph3Pd)C}-
CdNH, also unstable in the free state, has been obtained by
nucleophilic additions to metal-bound nitriles.7
We have previously described a family of acetimino
complexes of Ag(I),8 Au(I, III),9-11 Pt(II, IV),12 and Rh(I,
III)8,13,14 as well as the N-methylacetimino derivatives
[Au{N(Me)dCMe2}(PPh3)]OTf10 and[Ag{N(Me)dCMe2}2]-
X (X ) ClO4, OTf)15 which, along with [Pt(N,C,N-
L){N(Me)dCMe2}]OTf16 [LH ) 1,3-bis(piperidylmethyl)-
benzene], are the only N-methylacetimino complexes reported
so far. We have also reported the synthesis of the first
heteronuclear complexes bearing a bridging acetimido ligand,
namely cis- and trans-[PtCl{µ-N(AuPPh3)dCMe2}(PPh3)2]-
ClO4,12 and the first intramolecular aldol-like condensation
of two acetimino ligands into a 2-methyl-2-amino-4-imino-
pentano ligand that we found to occur at a Rh(III) center.13,14
With these precedents we intended the synthesis of acetimino
and N-methylacetimino complexes of Ir, which were un-
precedented, with the aim of finding new reactivity patterns.
This paper describes the first iridium complexes with the
iminoligandsMe2CdNR(R)H,Me),C,N-C6H4{C(Me)dNMe}-
2, and N,N′-RNdC(Me)CH2C(Me2)NHR (R-imam, R ) H,
Me) as well as some new methylamino derivatives that we
prepared with the purpose to use them as precursors of
N-methylacetimino complexes.
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 about 5 × 10-4 mol·L-1 acetone solutions with a
Crison Micro CM2200 conductimeter. IR spectra were recorded
on a Perkin-Elmer 16F PC FT-IR 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). In some cases the assignments were performed
with the help of APT, HMBC, and HMQC experiments and those
of the R-imam complexes 18-24 follow the atom numbering
scheme depicted in Chart 1. [IrCl(COD)]217 (COD ) 1,5-cyclooc-
18
tadiene), [Ir(Cp*)Cl(µ-Cl)]2 (Cp* ) pentamethylcyclopentadi-
enyl), [Ag(NH2Me)2]X15 (X ) ClO4, CF3SO3 (OTf)), [Ag{N(R)d
CMe2}2]X (R ) H, X ) ClO4,8 R ) Me, X ) ClO4, OTf15), and
[Au(NHdCMe2)(PPh3)]ClO410 were prepared according to literature
methods. TlOTf was obtained from OTfH and Tl2CO3 (Fluka).
t
XyNC (Xy ) C6H3Me2-2,6), BuNC, PPh3 (Fluka), MeNH2 (33%
wt 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 [Ir(Cp*)Cl2(NH2Me)] (1). To a suspension of
[Ir(Cp*)Cl(µ-Cl)]2 (100 mg, 0.13 mmol) in acetone (15 mL) was
added MeNH2 (31 µL, 0.26 mmol). The reaction mixture was stirred
for 4 h and filtered through Celite. The solution was concentrated
to 1 mL and Et2O (25 mL) was added. The resulting suspension
was filtered and the solid was washed with Et2O (3 × 5 mL) and
suction dried to give 1 as an orange powder. Yield: 100 mg, 0.23
mmol, 93%. Mp: 185 °C (dec). Molar conductivity: 1.1 Ω-1 cm2
mol-1. Anal. Calcd for C11H20Cl2IrN: C, 30.77; H, 5.69; N, 3.26.
(3) (a) Dunkin, I. R.; Thomson, P. C. P. Tetrahedron Lett. 1980, 21, 3813.
(b) Bock, H.; Dammel, R. J. Am. Chem. Soc. 1988, 110, 5261.
(4) Bock, H.; Dammel, R. Chem. Ber. 1987, 120, 1961.
(5) Duffaut, N.; Dupin, J. P. Bull. Soc. Chim. Fr. 1966, 3205.
(6) Guillemin, J. C.; Denis, J. M. Tetrahedron 1988, 44, 4431.
(7) (a) Bokach, N. A.; Kukushkin, V. Y.; Haukka, M.; Frausto da Silva,
J. J. R.; Pombeiro, A. J. L. Inorg. Chem. 2003, 42, 3602. (b)
Kukushkin, V. Y.; Pombeiro, A. J. L. Chem. ReV. 2002, 102, 1771.
(c) Michelin, R. A.; Mozzon, M.; Bertani, R. Coord. Chem. ReV. 1996,
147, 299. (d) Vicente, J.; Chicote, M. T.; Beswick, M. A.; Ram´ırez
de Arellano, M. C. Inorg. Chem. 1996, 35, 6592. (e) Vicente, J.;
Chicote, M. T.; Lagunas, M. C.; Jones, P. G. Inorg. Chem. 1995, 34,
5441. (f) Wagner, G.; Pakhomova, T. B.; Bokach, N. A.; Frausto da
Silva, J. J. R.; Vicente, J.; Pombeiro, A. J. L.; Kukushkin, V. Y. Inorg.
Chem. 2001, 40, 1683.
(8) Vicente, J.; Chicote, M. T.; Guerrero, R.; Vicente-Herna´ndez, I.; Jones,
P. G. Inorg. Chem. 2003, 42, 7644.
(9) Vicente, J.; Chicote, M.-T.; Abrisqueta, M.-D.; Guerrero, R.; Jones,
P. G. Angew. Chem., Int. Ed. Engl. 1997, 36, 1203.
(10) 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.
(11) Vicente, J.; Chicote, M. T.; Guerrero, R.; Ram´ırez de Arellano, M. C.
Chem. Commun. 1999, 1541.
1
Found: C, 30.73; H, 5.92; N, 3.02. H NMR (400 MHz, CDCl3,
δ): 1.70 (s, 15 H, Me, Cp*), 2.77 (t, 3 H, Me, 3JHH ) 6.7 Hz), 3.65
(br, 2 H, NH2). 13C{1H} NMR, APT (75 MHz, CDCl3, δ): 9.2 (Me,
Cp*), 32.9 (Me), 84.8 (C, Cp*).
Synthesis of [Ir(Cp*)Cl(NH2Me)2]Cl (2a). To a solution of
[Ir(Cp*)Cl(µ-Cl)]2 (300 mg, 0.38 mmol) in CH2Cl2 (10 mL) was
added MeNH2 (374 µL, 3.04 mmol). The resulting suspension was
stirred for 30 min and filtered. The solid was washed with Et2O (3
× 5 mL) and suction dried to give 2a, as a lemon-yellow powder.
Yield: 325 mg, 0.71 mmol, 94%. Mp: 185 °C (dec). Anal. Calcd
for C12H25Cl2IrN2: C, 31.30; H, 5.47; N, 6.08. Found: C, 31.36; H,
(12) Vicente, J.; Chicote, M. T.; Guerrero, R.; Vicente-Herna´ndez, I.; Jones,
P. G.; Bautista, D. Inorg. Chem. 2006, 45, 5201.
(13) Vicente, J.; Chicote, M. T.; Guerrero, R.; Vicente-Herna´ndez, I.;
´
Alvarez-Falco´n, M. M. Inorg. Chem. 2006, 45, 181.
(14) Vicente, J.; Chicote, M. T.; Guerrero, R.; Vicente-Herna´ndez, I.;
´
Alvarez-Falco´n, M. M.; Jones, P. G.; Bautista, D. Organometallics
2005, 24, 4506.
(15) Vicente, J.; Chicote, M. T.; Vicente-Herna´ndez, I.; Bautista, D. Inorg.
Chem. 2007, 46, 8939.
(16) Jude, H.; Bauer, A. K.; Connick, W. B. Inorg. Chem. 2002, 41, 2275.
(17) Herde, J. L.; Lambert, J. C.; Senoff, C. V. Inorg. Synth. 1974, 14, 18.
(18) White, C.; Yates, A.; Maitlis, P. M. Inorg. Synth. 1992, 29, 228.
Inorganic Chemistry, Vol. 47, No. 20, 2008 9593

Vicente et al.
1
5.58; N, 6.07. H NMR (200 MHz, dmso-d6, δ): 1.62 (s, 15 H,
concentrated to 1 mL and Et2O (25 mL) was added. The suspension
was filtered, and the solid was washed with Et2O (3 × 5 mL) and
suction dried to give 5·H2O or 6 as a yellow powder.
3
Me, Cp*), 2.46 (t, 6 H, Me, JHH ) 6.0 Hz), 5.02 (br, 2 H, NH2),
5.14 (br, 2 H, NH2). 13C{1H} NMR, APT (100 MHz, dmso-d6, δ):
8.4 (Me, Cp*), 32.8 (Me), 84.8 (C, Cp*).
5 · H2O: Yield: 45 mg, 0.07 mmol, 69%. Mp: 157 °C. Molar
conductivity: 125 Ω-1 cm2 mol-1. Anal. Calcd for C25H36F3IrN2O4S:
C, 42.30; H, 5.11; N, 3.95; S, 4.52. Found: C, 42.46; H, 4.88; N,
Synthesis of [Ir(Cp*)Cl(NH2Me)2]ClO4 (2b). To a suspension
of 2a (500 mg, 1.09 mmol) in acetone (30 mL) was added
NaClO4 ·H2O (610 mg, 4.34 mmol). The reaction mixture was
stirred for 30 min and concentrated to dryness. The residue was
stirred with CH2Cl2 (15 mL), and the resulting suspension was
filtered through Celite. The solution was concentrated to 2 mL,
Et2O (25 mL) was added, and the resulting suspension was filtered.
The solid was washed with Et2O (3 × 5 mL) and suction dried to
give 2b, as a yellow powder. Yield: 474 mg, 0.90 mmol, 83%.
Mp: 176 °C (dec). Molar conductivity: 158 Ω-1 cm2 mol-1. Anal.
Calcd for C12H25Cl2IrN2O4: C, 27.48; H, 4.80; N, 5.34. Found: C,
1
4.45; S, 4.38. H NMR (400 MHz, CDCl3, δ): 1.33 (s, 9 H, Me,
tBu), 1.57 (s, 2 H, H2O), 1.88 (s, 15 H, Me, Cp*), 2.63 (s, 3 H,
CMe), 3.90 (s, 3 H, NMe), 7.16-7.26 (m, 2 H, CH), 7.49-7.52
(m, 2 H, CH). 13C{1H} NMR, APT (100 MHz, CDCl3, δ): 9.1 (Me,
Cp*), 15.6 (CMe), 30.7 (Me, tBu), 48.4 (NMe), 58.4 (C, tBu), 96.2
(C, Cp*), 123.6 (CH), 129.0 (CH), 132.1 (CH), 135.0 (CH), 147.7
(ipso-C, Ar), 155.4 (C-Ir), 184.5 (C)N).
6: Yield: 47.5 mg, 0.06 mmol, 78%. Mp: 165 °C (dec). Molar
conductivity: 156 Ω-1 cm2 mol-1. Anal. Calcd for C29H34F3IrN2O3S:
C, 47.08; H, 4.63; N, 3.79; S, 4.33. Found: C, 46.71; H, 4.46; N,
1
27.67; H, 4.72; N, 5.68. H NMR (200 MHz, acetone-d6, δ): 1.75
3
1
(s, 15 H, Me, Cp*), 2.75 (t, 6 H, Me, JHH ) 6.4 Hz), 4.63 (br, 4
3.92; S, 4.40. H NMR (300 MHz, CDCl3, δ): 1.97 (s, 15 H, Me,
H, NH2). 13C{1H} NMR, APT (50 MHz, acetone-d6, δ): 8.4 (Me,
Cp*), 33.1 (Me), 86.2 (C, Cp*).
Cp*), 2.04 (s, 6 H, Me, Xy), 2.66 (s, 3 H, CMe), 3.98 (s, 3 H,
3
NMe), 7.04 (d, 2 H, CH, Xy, JHH ) 8.0 Hz), 7.14 (m, 1 H, CH,
3
4
Synthesis of [Ir(Cp*)(NH2Me)3](OTf)2 (3). To a suspension
of [Ir(Cp*)Cl(µ-Cl)]2 (103 mg, 0.13 mmol) in acetone (15 mL)
was added [Ag(NH2Me)2]OTf15 (165 mg, 0.52 mmol). The resulting
suspension was stirred for 30 min and filtered through Celite. The
solution was concentrated to 2 mL and Et2O (25 mL) was added.
The resulting suspension was filtered and the solid washed with
Et2O (3 × 5 mL) and suction dried to give 3, as a pale tan powder.
Yield: 156 mg, 0.22 mmol, 84%. Mp: 180 °C (dec). Molar
Xy), 7.21 (td, 1 H, CH, JHH ) 7.5 Hz, JHH ) 1.2 Hz), 7.28 (td,
1 H, CH, 3JHH ) 7.2 Hz, 4JHH ) 1.5 Hz), 7.53 (dd, 1 H, CH, 3JHH
) 7.5 Hz, 4JHH ) 1.5 Hz), 7.60 (dd, 1 H, CH, 3JHH ) 7.2 Hz, 4JHH
) 1.2 Hz). 13C{1H} NMR (300 MHz, CDCl3, δ): 9.3 (Me, Cp*),
15.7 (CMe), 18.2 (Me, Xy), 48.7 (NMe), 97.4 (C, Cp*), 124.1 (CH),
128.1 (meta-C, Xy), 129.2 (CH), 129.2 (para-C, Xy), 132.5 (CH),
134.7 (ortho-C, Xy), 135.4 (CH), 147.9 (ipso-C, Ph), 154.6 (C-Ir),
185.3 (C)N)
conductivity: 165 Ω-1 cm2 mol-1
C15H30F6IrN3O6S2: C, 25.07; H, 4.21; N, 5.85; S, 8.92. Found: C,
.
Anal. Calcd for
Synthesis of [Ir(NHdCMe2)2(COD)]ClO4 ·H2O (7·H2O). To
a solution of [IrCl(COD)]2 (313 mg, 0.47 mmol) in CH2Cl2 (20
mL) was added [Ag(NHdCMe2)2]ClO4 (300 mg, 0.93 mmol) under
nitrogen atmosphere. A suspension immediately formed which was
stirred for 30 min and filtered through Celite. The solution was
concentrated to 2 mL, Et2O (30 mL) was added, and the resulting
suspension was filtered. The solid was washed with Et2O (2 × 3
mL) and dried, first by suction and then in an oven at 60 °C for
24 h, to give 7·H2O, as a lemon-yellow solid. Yield: 438 mg, 0.82
mmol, 88%. Mp: 162 °C (dec). Molar conductivity: 163 Ω-1 cm2
mol-1. Anal. Calcd for C14H28ClIrN2O5: C, 31.73; H, 4.93; N, 5.37;
1
25.40; H, 4.49; N, 5.76; S, 8.70. H NMR (300 MHz, acetone-d6,
δ): 1.81 (s, 15 H, Me, Cp*), 2.76 (t, 9 H, Me, 3JHH ) 6.4 Hz), 4.93
(br, 6 H, NH2). 13C{1H} NMR, APT (75 MHz, acetone-d6, δ): 8.6
(Me, Cp*), 34.1 (Me), 88.4 (C, Cp*).
Synthesis of [Ir(Cp*){C,N-C6H4C(Me)dN(Me)-2}(NH2Me)]-
OTf·H2O (4·H2O). A yellow suspension of 3 (110 mg, 0.15 mmol)
in acetophenone (3 mL) was stirred at 80 °C for 4 h. The resulting
orange suspension was filtered through Celite, and the filtrate was
concentrated to 1 mL. Upon the addition of n-pentane (20 mL) an
oily solid formed. The mother liquor was decanted, and the residue
was stirred with Et2O (10 mL). The suspension was filtered, and
the solid was recrystallized from CH2Cl2/Et2O (1:10 mL) and dried,
first under nitrogen and then under vacuum for 4 h to give 4·H2O,
as a dark yellow powder. Yield: 75 mg, 0.11 mmol, 76%. Mp: 127
°C. Molar conductivity: 136 Ω-1 cm2 mol-1. Anal. Calcd for
C21H32F3IrN2O4S: C, 38.35; H, 4.90; N, 4.25; S, 4.87. Found: C,
1
Found: C, 31.60; H, 5.30; N, 5.27. H NMR (300 MHz, CDCl3,
δ): 1.62 (br, 2 H, H2O), 1.66 (m, 4 H, CH2), 2.22 (s, 6 H, Me),
2.26 (m, 4 H, CH2), 2.44 (s, 6 H, Me), 3.73 (br, 4 H, CH), 9.60
(br, 2 H, NH). 13C{1H} NMR, APT (75 MHz, CDCl3, δ): 28.1
(Me), 29.3 (Me), 31.1 (CH2), 67.6 (CH), 184.5 (C)N).
Synthesis of [Ir{N(Me)dCMe2}2(COD)]OTf ·H2O (8·H2O). A
solution containing AgOTf (125 mg, 0.47 mmol) and MeNH2 (121
µL, 0.97 mmol) in acetone (10 mL) was stirred in the dark for 1 h.
The solvent was removed under vacuum and CH2Cl2 (15 mL) and
[IrCl(COD)]2 (150 mg, 0.22 mmol) were succesively added to the
oily residue ([Ag{N(Me)dCMe2}2]OTf) under a nitrogen atmo-
sphere. A suspension immediately formed which was stirred for
30 min and filtered through Celite. The solution was concentrated
to 2 mL, Et2O (30 mL) was added, and the suspension was filtered
1
37.96; H, 4.70; N, 4.51; S, 4.92. H NMR (200 MHz, CDCl3, δ):
1.70 (s, 2 H, H2O), 1.74 (s, 15 H, Me, Cp*), 2.16 (t, 3 H, MeNH2,
3JHH ) 6.4 Hz), 2.56 (s, 3 H, CMe), 3.91 (s, 3 H, NMe), 7.13 (dt,
1 H, CH, JHH ) 7.5 Hz, JHH ) 1.2 Hz), 7.23 (dt, 1 H, CH,3JHH
3
4
) 7.5 Hz, 4JHH ) 1.2 Hz), 7.47 (dd, 1 H, CH, 3JHH ) 7.5 Hz, 4JHH
3
4
) 1.2 Hz), 7.71 (dd, 1 H, CH, JHH ) 7.5 Hz, JHH ) 1.2 Hz).
13C{1H} NMR, APT (100 MHz, CDCl3, δ): 9.0 (Me, Cp*), 15.1
(CMe), 34.6 (MeNH2), 46.2 (NMe), 89.2 (C, Cp*), 122.9 (CH),
128.6 (CH), 132.0 (CH), 134.5 (CH), 147.8 (ipso-C, Ar), 164.7
(C-Ir), 183.7 (C)N).
[Ir(Cp*){C,N-C6H4C(Me)dN(Me)-2}(CNR)]OTf ·nH2O [R )
tBu, n ) 1 (5·H2O); R ) Xy, n ) 0 (6)]. To a solution of 4·H2O
(for 5: 60 mg, 0.09 mmol; for 6: 50 mg, 0.08 mmol) in CHCl3 (20
mL) was added the appropriate RNC (for 5: R ) tBu, 65 µL, 0.58
mmol; for 6: R ) Xy, 15.4 mg, 0.12 mmol) and the reaction mixture
was heated in a Carius tube for 5 h at 75 °C (5) or refluxed for 8 h
(6). The resulting suspension was allowed to cool to room
temperature and then filtered through Celite. The filtrate was
under nitrogen. The solid was recrystallized from CH
2Cl2/Et2O (2:
25 mL), washed with Et2O (2 × 3 mL), and suction dried to give
8·H2O, as a yellow powder. Yield: 167 mg, 0.28 mmol, 63%. Mp:
125 °C (dec). Molar conductivity: 147 Ω-1 cm2 mol-1. Anal. Calcd
for C17H32F3IrN2O4S: C, 33.49; H, 5.29; N, 4.59; S, 5.26. Found:
1
C, 33.93; H, 5.39; N, 4.62; S, 4.67. H NMR (300 MHz, acetone-
d6, δ): Molar ratio A:B ) 2.25:1. Isomer A: 1.48-1.84 (m, 4 H,
CH2, overlapped with CH2 of isomer B), 2.11 (s, 6 H, CMe,
overlapped with Me of isomer B), 2.19-2.43 (m, 4 H, CH2,
overlapped with CH2 of isomer B), 2.81 (br, 2 H, H2O), 2.93 (s, 6
H, CMe), 3.34 (s, 6 H, NMe), 3.61 (m, 2 H, CH), 3.91 (m, 2 H,
9594 Inorganic Chemistry, Vol. 47, No. 20, 2008

Synthesis and ReactiWity of Ir(I) and Ir(III) Complexes
CH). Isomer B: 1.48-1.84 (m, 4 H, CH2, overlapped with CH2 of
isomer A), 2.11 (s, 6 H, CMe, overlapped with Me of isomer A),
2.19-2.43 (m, 4 H, CH2, overlapped with CH2 of isomer A), 2.71
(s, 6 H, CMe), 2.78 (br, 2 H, H2O), 3.48 (s, 6 H, NMe), 3.68 (m,
2 H, CH), 3.83 (m, 2 H, CH). (300 MHz, acetone-d6, 10 °C, δ):
Molar ratio A:B ) 2.25:1. Isomer A: 1.48-1.84 (m, 4 H, CH2,
overlapped with CH2 of isomer B), 2.10 (s, 6 H, CMe), 2.19-2.43
(m, 4 H, CH2, overlapped with CH2 of isomer B), 2.93 (q, 6 H,
CMe, 5JHH )1.2 Hz), 3.34 (s, 6 H, NMe), 3.59 (m, 2 H, CH), 3.87
(m, 2 H, CH). Isomer B: 1.48-1.84 (m, 4 H, CH2, overlapped with
CH2 of isomer A), 2.09 (s, 6 H, CMe), 2.19-2.43 (m, 4 H, CH2,
overlapped with CH2 of isomer A), 2.71 (s, 6 H, CMe), 3.47 (s, 6
H, NMe), 3.66 (m, 2 H, CH), 3.80 (m, 2 H, CH). (300 MHz,
acetone-d6, 50 °C, δ): 1.69 (br, 4 H, CH2), 2.13 (s, 6 H, CMe),
2.34 (br, 4 H, CH2), 2.93 (br, 6 H, CMe), 3.39 (br, 6 H, NMe),
3.64 (br, 2 H, CH), 3.91 (br, 2 H, CH). 13C{1H} NMR, APT (100
MHz, CDCl3, δ): Isomer A: 22.6 (CMe), 30.7 (CH2), 31.2 (CH2),
31.3 (CMe), 43.7 (NMe), 66.6 (CH), 67.2 (CH), 180.2 (C)N).
Isomer B: 22.6 (CMe), 31.0 (CH2), 31.1 (CH2), 31.6 (CMe), 43.3
(NMe), 65.9 (CH), 67.7 (CH), 180.2 (C)N).
3 H, Me), 2.25 (m, 4 H, CH2), 2.69 (s, 3 H, Me), 3.13 (m, 1 H,
CH), 3.26 (m, 1 H, CH), 3.32 (s, 3 H, NMe), 4.29 (m, 2 H, CH).
13C{1H} NMR, APT (100 MHz, CDCl3, δ): 22.2 (Me), 30.7 (Me),
30.8 (CH2), 31.0 (CH2), 31.9 (CH2), 32.3 (CH2), 42.5 (NMe), 57.2
(CH), 57.3 (CH), 68.4 (CH), 68.9 (CH), 175.3 (C)N).
Synthesis of [Ir(Cp*)(µ-Cl)(NHdCMe2)]2(ClO4)2 (12). To a
solution of [Ir(Cp*)Cl(µ-Cl)]2 (300 mg, 0.375 mmol) in CH2Cl2 (4
mL) was added [Au(NHdCMe2)(PPh3)]ClO4 (463 mg, 0.751
mmol). The reaction mixture was stirred for 1 h and filtered. The
solid was washed with CH2Cl2 (2 mL) and suction dried to give
12, as an orange powder. Yield: 280 mg, 0.27 mmol, 72%. Mp:
190 °C (dec). Anal. Calcd for C26H44Cl4N2O8Ir2: C, 30.06; H, 4.27;
1
N, 2.70. Found: C, 29.79; H, 4.14; N, 2.87. H NMR (300 MHz,
dmso-d6, δ): 1.65 (s, 15 H, Me, Cp*), 2.34 (s, 3 H, Me), 2.49 (s,
3 H, Me), 10.49 (br, 1 H, NH). 13C{1H} NMR, APT (75 MHz,
dmso-d6, δ): 8.2 (Me, Cp*), 27.0 (Me), 28.2 (Me), 93.8 (C, Cp*),
191.2 (C)N).
Synthesis of [Ir(Cp*)Cl(NHdCMe2)(PPh3)]ClO4 (13). To a
suspension of 12 (140 mg, 0.13 mmol) in CH2Cl2 (20 mL) was
added PPh3 (70.7 mg, 0.27 mmol). The reaction mixture was stirred
for 2 h and filtered through Celite. The solution was concentrated
to 1 mL, and Et2O (25 mL) was added. The suspension was filtered,
and the solid was suction dried to give 13, as a yellow powder.
Yield: 180 mg, 0.23 mmol, 85%. Mp: 198 °C (dec). Molar
cis-[Ir(NHdCMe2)2(CO)2]ClO4 (9). CO was bubbled for 10 min
through a solution of 7·H2O (400 mg, 0.75 mmol) in CH2Cl2 (20
mL). The solution was stirred for 20 min, concentrated to 1 mL,
and Et2O (20 mL) was added. The suspension was filtered under
nitrogen, and the solid was suction dried to give 9, as a pale yellow
solid. Yield: 332 mg, 0.72 mmol, 96%. Mp: 126 °C (dec). Molar
conductivity: 123 Ω-1 cm2 mol-1. Anal. Calcd for C8H14ClIrN2O6:
conductivity: 150 Ω-1 cm2 mol-1
.
Anal. Calcd for
C31H37Cl2IrNO4P: C, 47.63; H, 4.77; N, 1.79. Found: C, 47.68; H,
4.72; N, 1.93. 1H NMR (300 MHz, CDCl3, δ): 1.51 (d, 15 H, Me,
Cp*, 4JHP ) 2.4 Hz), 2.00 (d, 3 H, Me, 4JHH ) 0.9 Hz), 2.22 (s, 3
H, Me), 7.48 (br, 15 H, Ph), 9.14 (br, 1 H, NH). 13C{1H} NMR,
APT (75 MHz, CDCl3, δ): 8.7 (Me, Cp*), 26.5 (Me), 29.9 (Me),
94.2 (d, C, Cp*, 2JCP ) 2 Hz), 128.6 (d, ortho-Ph, 2JCP ) 15 Hz),
131.4 (meta-Ph), 134.7 (para-Ph,), 190.10 (C)N). 31P{1H} NMR
(121 MHz, CDCl3, δ): 8.9.
1
C, 20.80; H, 3.06; N, 6.07. Found: C, 20.54; H, 3.03; N, 6.42. H
NMR (400 MHz, CDCl3, δ): 2.38 (s, 3 H, Me), 2.47 (s, 3 H, Me),
9.64 (br, 1 H, NH). 13C{1H} NMR, APT (100 MHz, CDCl3, δ):
29.1 (Me), 29.5 (Me), 171.5 (CO), 193.4 (C)N).
Synthesis of [IrCl(NHdCMe2)(COD)] ·H2O (10 ·H2O). A
suspension containing Me4NCl (15 mg, 0.13 mmol) in acetone (60
mL) was treated for 5 min in an ultrasound bath. 7·H2O (60 mg,
0.11 mmol) was then added, and the reaction mixture was stirred
under nitrogen atmosphere for 5 h and concentrated under vacuum
to dryness. The residue was extracted with Et2O (2 × 20 mL), and
the suspension was filtered through Celite. The filtrate was
concentrated under vacuum to dryness, and the residue was stirred
with n-pentane (10 mL). The suspension was filtered, and the solid
was recrystallized from CH2Cl2/pentane (2:25 mL), and suction
dried to give 10 ·H2O as a yellow powder. Yield: 35 mg, 0.09 mmol,
Synthesis of [Ir(Cp*)Cl2(NHdCMe2)] · H2O (14 · H2O). A
suspension containing 12 (168 mg, 0.16 mmol) and Me4NCl (43
mg, 0.39 mmol) in acetone (40 mL) was stirred under nitrogen for
6 h. The reaction mixture was concentrated to dryness, and the
residue was stirred with CH2Cl2 (10 mL). The resulting suspension
was filtered through Celite, the solution was concentrated to 1 mL,
and n-pentane (25 mL) was added. The suspension was filtered,
the solid was recrystallized from CH2Cl2/Et2O (2:25 mL), and dried,
first by suction and then in an oven at 60 °C for 14 h, to give
14·H2O, as a yellow powder. Yield: 120 mg, 0.26 mmol, 81%.
Mp: 167 °C (dec). Molar conductivity: 1.5 Ω-1 cm2 mol-1. Anal.
Calcd for C13H24Cl2IrNO: C, 32.98; H, 5.11; N, 2.96. Found: C,
82%. Mp: 149 °C (dec). Molar conductivity: 1.7 Ω-1 cm2 mol-1
.
Anal. Calcd for C11H21ClIrNO: C, 32.15; H, 5.11; N, 3.41. Found:
1
C, 32.33; H, 4.92; N, 3.76. H NMR (400 MHz, CDCl3, δ): 1.53
1
(br, 4 H, CH2), 1.73 (br, 2 H, H2O), 2.19 (s, 3 H, Me), 2.22 (m, 4
H, CH2), 2.48 (s, 3 H, Me), 3.27 (br, 2 H, CH), 4.30 (br, 2 H, CH),
8.99 (br, 1 H, NH). 13C{1H} NMR, APT (75 MHz, CDCl3, δ):
27.5 (Me), 30.2 (Me), 31.0 (CH2), 32.0 (CH2), 57.4 (CH), 70.0
(CH), 183.2 (C)N).
32.83; H, 4.98; N, 3.09. H NMR (400 MHz, CDCl3, δ): 1.61 (s,
2 H, H2O), 1.66 (s, 15 H, Me, Cp*), 2.38 (d, 3 H, Me, 4JHH ) 1.3
Hz), 2.38 (s, 3 H, Me), 9.35 (br, 1 H, NH). 13C{1H} NMR, APT
(100 MHz, CDCl3, δ): 9.1 (Me, Cp*), 26.0 (Me), 30.5 (Me), 85.6
(C, Cp*), 184.4 (C)N).
Synthesis of [Ir(Cp*)Cl2(NH3)] (15). In an attempt to grow
single crystals of 14·H2O by the liquid diffusion method, using
CH2Cl2 and Et2O, orange crystals of the hydrolysis product 15 grew
instead which allowed its crystal structure to be determined.
Additionally, after washing a crop of crystals with n-pentane and
drying them under nitrogen, they were used to obtain the data
reported below. Mp: 182 °C (dec). Anal. Calcd for C10H18Cl2NIr:
Synthesis of [IrCl{N(Me)dCMe2}(COD)] ·0.5H2O (11 ·
0.5H2O). To a solution of 8·H2O (91 mg, 0.15 mmol) in CH2Cl2
(15 mL) was added PPNCl (88.3 mg, 0.15 mmol). The reaction
mixture was stirred for 5 h and concentrated under vacuum to
dryness. Et2O (30 mL) was added, and the resulting suspension
was filtered through Celite. The filtrate was concentrated to dryness,
and the residue was stirred with n-pentane (10 mL). The suspension
was filtered under a nitrogen atmosphere, and the solid collected
was suction dried to give 11·0.5H2O as a yellow powder. Yield:
40 mg, 0.10 mmol, 64%. Mp: 133 °C (dec). Molar conductivity:
1.5 Ω-1 cm2 mol-1. Anal. Calcd for C12H22ClIrNO0.5: C, 34.65; H,
1
C, 28.91; H, 4.37; N, 3.37. Found: C, 28.91; H, 4.26; N, 3.30. H
NMR (300 MHz, CDCl3, δ): 1.71 (s, 15 H, Me, Cp*), 3.19 (br, 3
H, NH3).
Synthesis of [Ir(Cp*)(NHdCMe2)3](ClO4)2 (16a). To a suspen-
sion of [Ir(Cp*)Cl(µ-Cl)]2 (180 mg, 0.225 mmol) in acetone (10
mL) was added [Ag(NHdCMe2)2]ClO4 (302 mg, 0,901 mmol). The
1
5.33; N, 3.37. Found: C, 34.89; H, 5.32; N, 3.22. H NMR (400
MHz, CDCl3, δ): 1.48 (m, 4 H, CH2), 1.83 (s, 1 H, H2O), 2.04 (s,
Inorganic Chemistry, Vol. 47, No. 20, 2008 9595

Vicente et al.
reaction mixture was stirred for 5 min, filtered through Celite, and
the yellow solution was concentrated to 2 mL. Et2O (25 mL) was
added, the resulting suspension was filtered, and the solid was
recrystallized from acetone/Et2O (5 × 25 mL), washed successively
with CHCl3 (3 × 5 mL) and Et2O (3 × 5 mL), and suction dried
to give 16a, as a pale tan solid. Yield: 298 mg, 0.427 mmol, 90%.
Mp: 195 °C (dec). Molar conductivity: 185 Ω-1 cm2 mol-1. Anal.
Calcd for C19H36Cl2IrN3O8: C, 32.71; H, 5.20; N, 6.02. Found: C,
1 H, NH). 13C{1H} NMR, APT, HMQC, HMBC (75 MHz, dmso-
d6, δ): 8.4 (Me, Cp*), 23.6 (Me6), 29.3 (Me7), 29.6 (Me5), 46.4
(C2), 47.3 (C3), 86.9 (C, Cp*), 183.0 (C1).
Synthesis of [Ir(Cp*)Cl(H-imam)]ClO4 (18b). To a suspension
of 18a (100 mg, 0.19 mmol) in acetone (20 mL) was added
NaClO4 ·H2O (109 mg, 0.77 mmol), and the reaction mixture was
stirred for 1 h. It was then concentrated under vacuum to dryness,
the residue was stirred with CH2Cl2 (20 mL), and the resulting
suspension was filtered through Celite. The solution was concen-
trated to 2 mL, Et2O (25 mL) was added, the suspension was
filtered, and the solid was washed with Et2O (3 × 5 mL) and suction
dried to give 18b as a yellow powder. Yield: 103 mg, 0.18 mmol,
1
32.34; H, 5.52; N, 5.89. H NMR (200 MHz, acetone-d6, δ): 1.74
4
(s, 15 H, Me, Cp*), 2.16 (d, 9 H, Me, JHH ) 0.6 Hz), 2.54 (d, 9
H, Me, 4JHH ) 1.4 Hz), 10.25 (br, 3 H, NH). 13C{1H} NMR, APT
(100 MHz, acetone-d6, δ): 8.8 (Me, Cp*), 26.2 (Me), 29.5 (Me),
91.0 (C, Cp*), 192.8 (C)N).
91%. Mp: 232 °C (dec). Molar conductivity: 157 Ω-1 cm2 mol-1
.
Synthesis of [Ir(Cp*)(NHdCMe2)3]Cl(ClO4) (16b). To a
suspension of 16a (141 mg, 0.20 mmol) in acetone (5 mL) was
added PPNCl (116 mg, 0.20 mmol). After 2 h of stirring, the
suspension was filtered, and the solid was washed with Et2O (3 ×
5 mL) and suction dried to give 16b, as a white powder. Yield:
109 mg, 0.17 mmol, 85%. Mp: 180 °C (dec). Molar conductivity:
133 Ω-1 cm2 mol-1. Anal. Calcd for C19H36Cl2IrN3O4: C, 36.02;
H, 5.73; N, 6.63. Found: C, 36.11; H, 5.90; N, 6.66. 1H NMR (300
MHz, dmso-d6, δ): 1.60 (s, 15 H, Me, Cp*), 1.83 (s, 9 H, Me),
2.39 (s, 9 H, Me), 11.38 (br, 3 H, NH). (300 MHz, dmf-d7, δ):
1.73 (s, 15 H, Me, Cp*), 2.02 (s, 9 H, Me), 2.52 (s, 9 H, Me),
12.04 (br, 3 H, NH). (300 MHz, dmf-d7, -58 °C, δ): 1.63 (br, 3
H, Me), 1.72 (s, 15 H, Me, Cp*), 2.16 (s, 6 H, Me), 2.33 (br, 3 H,
Me), 2.48 (s, 6 H, Me), 10.94 (br, 1 H, NH), 12.52 (br, 2 H, NH).
13C{1H} NMR, APT (400 MHz, dmso-d6, δ): 8.2 (Me, Cp*), 25.4
(Me), 28.2 (Me), 89.0 (C, Cp*), 188.9 (C)N). MS (FAB+): (m/z,
%) [M+] 534.1, 34; [M+ - Cl - Me2CdNH] 441.2, 100.0.
[Ir(Cp*)(NHdCMe2)3]Cl2 (16c). In an attempt to grow single
crystals of 16b by slow diffusion of an acetone solution of 16a
through another of PPNCl in the same solvent, crystals of 16c grew
instead which were used for measuring its 1H NMR spectrum (300
MHz, dmso-d6, δ: 1.60 (s, 15 H, Me, Cp*), 1.83 (s, 9 H, Me), 2.40
(s, 9 H, Me), 11.54 (br, 3 H, NH)) and for an X-ray diffraction
study.
Anal. Calcd for C16H29Cl2IrN2O4: C, 33.33; H, 5.07; N, 4.86. Found:
1
C, 33.72; H, 5.33; N, 4.93. H NMR (400 MHz, acetone-d6, δ):
1.19 (s, 3 H, Me6), 1.54 (s, 3 H, Me7), 1.75 (s, 15 H, Me, Cp*),
2.36 (d, 3 H, Me5, 4JHH ) 2 Hz), 2.63 (s, 2 H, CH2), 4.21 (br, 1 H,
NH2), 5.31 (br, 1 H, NH2), 10.84 (br, 1 H, NH). Crystals of 18b
suitable for an X-ray diffraction study grew from acetone/Et2O by
the liquid diffusion method.
Synthesis of [Ir(Cp*)Cl(Me-imam)]ClO4 (19). A solution of
2b (161 mg, 0.31 mmol) in acetone (15 mL) was refluxed for 7 h,
and the reaction mixture was filtered through Celite. The solution
was concentrated to 2 mL, and Et2O (25 mL) was added. The
resulting suspension was filtered, and the solid washed with Et2O
(3 × 5 mL) and suction dried to give 19 as a yellow powder. Yield:
174 mg, 0.29 mmol, 94%. Mp: 200 °C (dec). Molar conductivity:
158 Ω-1 cm2 mol-1. Anal. Calcd for C18H33Cl2IrN2O4: C, 35.76;
H, 5.50; N, 4.63. Found: C, 35.39; H, 5.35; N, 4.36. 1H NMR (400
MHz, acetone-d6, δ): Molar ratio A:B ) 1:1.7. Isomer A: 0.99 (s,
3 H, Me6), 1.51 (s, 3 H, Me7), 1.68 (s, 15 H, Me, Cp*), 2.38 (d,
2
1 H, CH2, JHH ) 15 Hz), 2.55 (s, 3 H, Me5), 2.79 (d, 3 H, Me8,
2
3JHH ) 6 Hz), 2.94 (d, 1 H, CH2, JHH ) 15 Hz), 3.70 (br, 1 H,
NH), 3.76 (s, 3 H, Me4). Isomer B: 1.36 (s, 3 H, Me6), 1.46 (s, 3
2
H, Me7), 1.73 (s, 15 H, Me, Cp*), 2.35 (d, 1 H, CH2, JHH ) 13
Hz), 2.58 (s, 3 H, Me5), 2.93 (d, 3 H, Me8, 3JHH ) 6 Hz), 3.13 (d,
1 H, CH2, 2JHH ) 13 Hz), 3.64 (s, 3 H, Me4), 5.13 (br, 1 H, NH).
13C{1H} NMR, APT, HMQC, HMBC (100 MHz, acetone-d6, δ):
Isomer A: 8.6 (Me, Cp*), 19.6 (Me6), 25.8 (Me5), 26.4 (Me7),
36.9 (Me8), 48.6 (Me4), 55.2 (C2), 56.6 (C3), 88.3 (C, Cp*), 183.6
(C1). Isomer B: 9.7 (Me, Cp*), 25.1 (Me5 + Me6), 25.5 (Me7),
37.1 (Me8), 47.3 (Me4), 58.1 (C2), 60.0 (C3), 88.2 (C, Cp*), 184.4
(C1).
Synthesis of [Ir(Cp*)Cl(NHdCMe2)2]ClO4 (17). A suspension
containing 14·H2O (185 mg, 0.39 mmol) and 16a (271 mg, 0.39
mmol) in CH2Cl2 (25 mL) was stirred for 24 h. It was then filtered
through Celite, the solution was concentrated to 2 mL, and Et2O
(25 mL) was added. The resulting suspension was filtered, and the
solid was washed with Et2O (3 × 5 mL) and suction dried to give
17, as a yellow powder. Yield: 413 mg, 0.72 mmol, 92%. Mp: 147
°C. Molar conductivity: 156 Ω-1 cm2 mol-1. Anal. Calcd for
C16H29Cl2IrN2O4: C, 33.33; H, 5.07; N, 4.86. Found: C, 33.12; H,
Synthesis of [Ir(Cp*)(H-imam)(CNR)](ClO4)2 (R ) tBu,
20; Xy, 21). To a solution of 18b (for 20: 25 mg, 0.04 mmol; for
21: 48 mg, 0.08 mmol) in acetone (10 mL) were successively added
equimolar amounts of AgClO4 and RNC. The resulting suspension
was stirred for 1 h and filtered through Celite. The solution was
concentrated to 1 mL, Et2O (25 mL) was added, the suspension
was filtered, and the solid collected was washed with Et2O (3 × 5
mL) and suction dried to give 20 or 21 as a white powder.
20: Yield: 25 mg, 0.03 mmol, 80%. Mp: 162 °C (dec). Molar
conductivity: 210 Ω-1 cm2 mol-1. Anal. Calcd for C21H38Cl2IrN3O8:
1
5.55; N 4.72. H NMR (400 MHz, acetone-d6, δ): 1.66 (s, 15 H,
4
Me, Cp*), 2.43 (s, 6 H, Me), 2.47 (d, 6 H, Me, JHH ) 1.1 Hz),
9.83 (br, 2 H, NH). 13C{1H} NMR, APT (100 MHz, acetone-d6,
δ): 9.0 (Me, Cp*), 26.7 (Me), 29.9 (Me), 88.1 (C, Cp*), 190.3
(C)N).
Synthesis of [Ir(Cp*)Cl(H-imam)]Cl (18a). To a solution of
17 (90 mg, 0.156 mmol) in acetone (3 mL) was added PPNCl (89.6
mg, 0.156 mmol), and the reaction mixture was stirred for 24 h.
The resulting suspension was filtered, and the solid washed with
Et2O (3 × 5 mL) and suction dried to give 18a as a yellow powder.
Yield: 36 mg, 0.07 mmol, 45%. Mp: 230 °C (dec). 18a is not
soluble enough in acetone for conductivity measurements. Anal.
Calcd for C16H29Cl2IrN2: C, 37.49; H, 5.70; N, 5.47. Found: C,
37.75; H, 5.88; N, 5.36. 1H NMR (300 MHz, dmso-d6, δ): 0.92 (s,
3 H, Me6), 1.39 (s, 3 H, Me7), 1.66 (s, 15 H, Me, Cp*), 2.36 (s,
3 H, Me5), 2.40 (s, 1 H, CH2), 2.42 (s, 1 H, CH2), 4.21 (d, 1 H,
NH2, 2JHH ) 12 Hz), 5.67 (d, 1 H, NH2, 2JHH ) 12 Hz), 11.27 (br,
1
C, 34.86; H, 5.29; N, 5.81. Found: C, 34.65; H, 5.58; N, 5.57. H
NMR (400 MHz, dmso-d6, δ): 1.13 (s, 3 H, Me6), 1.21 (s, 3 H,
t
Me7), 1.53 (s, 9 H, Me, Bu), 1.85 (s, 15 H, Me, Cp*), 2.26, 2.53
(AB system, 2 H, CH2, JAB ) 17 Hz), 2.40 (s, 3 H, Me5), 4.77 (d,
1 H, NH2, 2JHH ) 12 Hz), 6.19 (d, 1 H, NH2, 2JHH ) 12 Hz), 11.02
(br, 1 H, NH). 13C{1H} NMR, APT, HMQC, HMBC (100 MHz,
t
dmso-d6, δ): 8.2 (Me, Cp*), 25.9 (Me6 + Me7), 29.5 (Me, Bu),
t
30.0 (Me5), 47.3 (C2), 49.2 (C3), 59.4 (C, Bu), 94.8 (C, Cp*),
187.6 (C1).
9596 Inorganic Chemistry, Vol. 47, No. 20, 2008

Synthesis and ReactiWity of Ir(I) and Ir(III) Complexes
21: Yield: 59 mg, 0.07 mmol, 92%. Mp: 150 °C (dec). Molar
conductivity: 206 Ω-1 cm2 mol-1. Anal. Calcd for C25H38Cl2IrN3O8:
C, 38.91; H, 4.96; N, 5.45. Found: C, 38.80; H, 5.18; N, 5.31. H
NMR, (300 MHz, acetone-d6, δ): 1.34 (s, 3 H, Me6), 1.51 (s, 3 H,
Me7), 2.09 (s, 15 H, Me, Cp*), 2.48 (s, 6 H, Me, Xy), 2.62 (d, 3
H, Me5, 4JHH ) 1 Hz), 2.80, 2.96 (AB system, 2 H, CH2, JAB ) 18
conductivity: 23b is poorly soluble in acetone. Anal. Calcd for
C19H36Cl2IrN3O4: C, 36.02; H, 5.73: N, 6.63. Found: C, 35.96; H,
6.03; N, 6.43. 1H NMR (300 MHz, dmso-d6, δ): 0.82 (s, 3 H, Me6),
1.49 (s, 3 H, Me7), 1.67 (s, 15 H, Me, Cp*), 1.77 (d, 1 H, CH2,
2JHH ) 15 Hz), 2.04 (s, 3 H, Me), 2.29 (s, 3 H, Me5), 2.38 (s, 3 H,
1
Me), 5.32 (d, 1 H, NH2, 2JHH ) 12 Hz), 6.03 (d, 1 H, NH2, 2JHH
)
2
2
12 Hz), 11.50 (br, 1 H, NH), 11.56 (br, 1 H, NH). 13C{1H} NMR,
APT, HMQC, HMBC (75 MHz, dmso-d6, δ): 8.2 (Me, Cp*), 23.0
(Me6), 25.7 (Me), 28.3 (Me), 28.7 (Me7), 29.5 (Me5), 46.5 (C2),
47.3 (C3), 88.2 (C, Cp*), 184.9 (C1), 188.7 (C)N).
Hz), 4.80 (d, 1 H, NH2, JHH ) 9 Hz), 6.08 (d, 1 H, NH2, JHH
)
9 Hz), 7.26-7.36 (m, 3 H, CH, Xy), 10.89 (br, 1 H, NH). 13C{1H}
NMR, APT, HMQC, HMBC (75 MHz, acetone-d6, δ): 8.2 (Me,
Cp*), 18.0 (Me, Xy), 24.9 (Me6), 26.7 (Me7), 30.1 (Me5), 47.9
(C2), 50.1 (C3), 97.1 (C, Cp*), 128.1 (meta-C), 130.2 (para-C),
136.2 (ortho-C, Xy), 189.6 (C1).
Synthesis of [Ir(Cp*)(Me-imam)(CNXy)](ClO4)2 (24). To a
solution of 22·H2O (60 mg, 0.08 mmol) in acetone (10 mL) was
added XyNC (11 mg, 0.08 mmol). The reaction mixture was stirred
for 2 h, filtered through Celite, and the solution was concentrated
to 2 mL. Et2O (25 mL) was added, and the suspension was filtered.
The solid collected was washed with Et2O (3 × 5 mL) and suction
dried to give 24 as a pale tan powder. Yield: 62 mg, 0.077 mmol,
Synthesis of [Ir(Cp*)(Me-imam)(NCMe)](ClO4)2 ·H2O (22 ·
H2O). To a solution of 19 (150 mg, 0.25 mmol) in MeCN (15 mL)
was added AgClO4 (51.4 mg, 0.25 mmol). The resulting suspension
was stirred for 2 h, filtered through Celite, and the solution
concentrated to 2 mL. Et2O (25 mL) was added, and the suspension
was filtered. The solid collected was washed with Et2O (3 × 5
mL) and suction dried to give 22 ·H2O as a pale tan powder. Yield:
158 mg, 0.22 mmol, 87%. Mp: 161 °C (dec). Molar conductivity:
130 Ω-1 cm2 mol-1. Anal. Calcd for C20H38Cl2IrN3O9: C, 33.01;
H, 5.26; N, 5.77. Found: C, 33.20; H, 5.03; N, 5.93. 1H NMR (300
MHz, acetone-d6, δ): Molar ratio A:B ) 1.7:1. Isomer A: 1.02 (s,
3 H, Me6), 1.58 (s, 3 H, Me7), 1.82 (s, 15 H, Me, Cp*), 2.34 (d,
1 H, CH2, 2JHH ) 16 Hz), 2.62 (s, 3 H, Me5), 2.84 (br, 2 H, H2O),
92%. Mp: 157 °C (dec). Molar conductivity: 218 Ω-1 cm2 mol-1
.
Anal. Calcd for C27H42Cl2N3IrO8: C, 40.55; H, 5.29; N, 5.25. Found:
C, 40.60; H, 5.59; N, 5.36. 1H NMR (300 MHz, dmso-d6, δ): Molar
ratio A:B ) 3.7:1. Isomer A: 0.90 (s, 3 H, Me6), 1.47 (s, 3 H,
Me7), 1.88 (s, 15 H, Me, Cp*), 2.01 (d, 1 H, CH2, 2JHH ) 16 Hz),
2.47 (s, 6 H, Me, Xy), 2.52 (s, 3 H, Me5), 2.92 (d, 3 H, Me8, 3JHH
2
) 5 Hz), 3.00 (d, 1 H, CH2, JHH ) 16 Hz), 3.80 (s, 3 H, Me4),
3
5.42 (q, 1 H, NH, JHH ) 5 Hz), 7.34-7.43 (m, 3 H, CH, Xy).
3
Isomer B: 1.16 (s, 3 H, Me6), 1.30 (s, 3 H, Me7), 1.89 (s, 15 H,
Me, Cp*), 2.49 (br, 3 H, Me5), 2.51 (s, 6 H, Me, Xy), 2.80 (d, 3
H, Me8, 3JHH ) 6 Hz), 3.10 (d, 1 H, CH2, 2JHH ) 14 Hz), 3.73 (s,
3 H, Me4), 6.34 (br, 1 H, NH), 7.34-7.43 (m, 3 H, CH, Xy).
13C{1H} NMR, APT, HMQC (75 MHz, dmso-d6, δ): Isomer A:
8.5 (Me, Cp*), 18.7 (Me, Xy), 19.2 (Me6), 24.5 (Me7), 26.3 (Me5),
43.2 (Me8), 52.6 (Me4), 54.1 (C2), 56.3 (C3), 97.4 (C, Cp*), 126.6
(ipso-C), 128.4 (meta-C), 130.5 (para-C), 136.0 (ortho-C), 188.5
(C1). Isomer B: 9.3 (Me, Cp*), 18.6 (Me, Xy), 23.9 (Me6), 24.0
(Me7), 24.9 (Me5), 39.9 (Me8), 52.0 (Me4), 57.0 (C2), 60.0 (C3),
96.8 (C, Cp*), 128.4 (meta-C), 129.4 (ipso-C), 131.1 (para-C),
136.4 (ortho-C), 187.1 (C1).
2.94 (s, 3 H, Me, MeCN), 2.95 (d, 3 H, Me8, JHH ) 6 Hz), 3.09
2
(d, 1 H, CH2, JHH ) 16 Hz), 3.92 (s, 3 H, Me4), 5.28 (br, 1 H,
NH). Isomer B: 1.35 (s, 3 H, Me6), 1.50 (s, 3 H, Me7), 1.83 (s, 15
2
H, Me, Cp*), 2.20 (d, 1 H, CH2, JHH ) 14 Hz), 2.55 (s, 3 H,
Me5), 2.89 (s, 3 H, Me, MeCN), 2.96 (d, 3 H, Me8, 3JHH ) 5 Hz),
2
3.19 (d, 1 H, CH2, JHH ) 14 Hz), 3.75 (s, 3 H, Me4), 4.68 (br, 1
H, NH). 13C{1H} NMR, APT, HMQC, HMBC (75 MHz, acetone-
d6, δ): Isomer A: 4.4 (MeCN), 8.7 (Me, Cp*), 19.8 (Me6), 26.0
(Me7), 26.2 (Me5), 38.9 (Me8), 49.4 (Me4), 55.5 (C2), 57.2 (C3),
92.1 (C, Cp*), 187.4 (C1). Isomer B: 4.8 (MeCN), 9.6 (Me, Cp*),
24.6 (Me7), 24.8 (Me6), 25.3 (Me5), 38.1 (Me8), 47.9 (Me4), 58.3
(C2), 60.3 (C3), 91.7 (C, Cp*), 187.4 (C1).
X-ray Structure Determinations of 15, 16c, and 18b. Crystal
data and refinement details for 15 and 16c are presented in Table
1. The three crystals were measured on a Bruker Smart APEX
diffractometer. Data were collected using monochromated Mo KR
radiation in ω scan mode. Absorption corrections were applied on
the basis of multiscans (Program SADABS). All of the non-
hydrogen atoms were refined anisotropically on F2 (program
SHELX-97, G. M. Sheldrick, University of Go¨ttingen, Go¨ttingen,
Germany). The NH hydrogens were refined freely with SADI, the
methyl groups were refined using rigid groups (AFIX 137), and
the other hydrogens were refined using a riding model. Special
features: For 18b, the crystal structure of 18b was solved in Pna21
(a ) 26.6907(53) Å, b ) 8.1806(16) Å, c ) 27.9305(56) Å,
orthorhombic, T ) 100(2) K, Z ) 12, 67515 reflections measured,
14190 unique (Rint ) 0.038). Although the connectivity of the cation
could be established unambiguously, some irregularities in the bond
distances and angles of the different molecules made it impossible
to refine the structure properly. The pseudosymmetry problem along
with the presence of heavy atoms, impeded the direct location of
the hydrogen atoms.
Synthesis of [Ir(Cp*)(H-imam)(NHdCMe2)](ClO4)2 (23a). To
a solution of 18b (60 mg, 0.10 mmol) in CH2Cl2 (10 mL) was
added [Ag(NHdCMe2)2]ClO4 (33.5 mg, 0.10 mmol). The resulting
suspension was stirred for 1 h and filtered through Celite. The
solution was concentrated to 1 mL, Et2O (25 mL) was added, the
suspension was filtered, and the solid collected was washed with
Et2O (3 × 5 mL) and suction dried to give 23a as a white powder.
Yield: 66 mg, 0.09 mmol, 91%. Mp: 217 °C (dec). Molar
conductivity: 180 Ω-1 cm2 mol-1. Anal. Calcd for C19H36Cl2IrN3O8:
1
C, 32.71; H, 5.20; N, 6.02. Found: C, 32.64; H, 5.43; N, 5.92. H
NMR (400 MHz, acetone-d6, δ): 1.17 (s, 3 H, Me6), 1.55 (s, 3 H,
Me7), 1.81 (s, 15 H, Me, Cp*), 2.23 (d, 1 H, CH2, 2JHH ) 17 Hz),
4
2.34 (s, 3 H, Me trans-Ir), 2.46 (d, 3 H, Me5, JHH )1 Hz), 2.52
4
2
(d, 3 H, Me trans-H, JHH ) 1 Hz), 2.70 (d, 1 H, CH2, JHH ) 17
Hz), 4.61 (d, 1 H, NH2, 2JHH ) 11 Hz), 5.36 (d, 1 H, NH2, 2JHH
)
11 Hz), 10.10 (br, 1 H, NH), 11.08 (br, 1 H, NH). 13C{1H} NMR
APT, HMQC, HMBC (100 MHz, acetone-d6, δ): 8.7 (Me, Cp*),
24.1 (Me6), 26.8 (Me, trans-Ir), 29.7 (Me7 + Me trans-H), 31.0
(Me5), 47.5 (C2), 49.6 (C3), 90.3 (C, Cp*), 188.2 (C1), 193.2
(C)N).
Synthesis of [Ir(Cp*)(H-imam)(NHdCMe2)]Cl(ClO4) (23b).
To a solution of 23a (50 mg, 0.07 mmol) in acetone (10 mL) was
added PPNCl (41.2 mg, 0.07 mmol). The resulting suspension was
stirred for 4 h and filtered. The solid collected was washed with
Et2O (3 × 5 mL) and suction dried to give 23b as a white powder.
Yield: 37 mg, 0.06 mmol, 81%. Mp: 185 °C (dec). Molar
Discussion
Synthesis of Imino Iridium Complexes. To prepare
iridium imino complexes we have studied two alternative
methods, the reaction of iridium methylamino complexes
Inorganic Chemistry, Vol. 47, No. 20, 2008 9597

Vicente et al.
Table 1. Crystal Data and Structure Refinement of 15 and 16c
Scheme 1
15
16c
formula
fw
C10H18Cl2IrN
415.35
C19H36Cl2IrN3
569.61
T(K)
100(2)
monoclinic
P2(1)/c
8.6828(6)
7.7401(5)
19.4092(13)
101.791(2)
1276.89(15)
4
298(2) K
monoclinic
P2(1)/n
10.6457(6)
13.6922(7)
15.9691(8)
99.821(2)
2293.6(2)
4
cryst syst
space group
a (Å)
b (Å)
c (Å)
ꢀ (deg)
V (Å3)
Z
Fcalcd (Mg m-3
)
2.161
10.839
784
1.650
6.061
1128
µ(Mo KR) (mm-1
F(000)
)
cryst size (mm)
θ range (deg)
reflns collected
0.08 × 0.07 × 0.06
2.14 to 28.13
14215
0.29 × 0.27 × 0.09
1.97 to 28.09
25654
independent reflns (Rint
)
2964 (0.021)
0.562 and 0.478
3/144
1.134
0.0208
5278 (0.020)
0.611 and 0.272
3/249
1.051
0.0187
max. and min. transmsn
restraints/parameters
goodness-of-fit on F2
R1 (I > 2σ(I)]
wR2 (all reflns)
0.0465
0.0471
largest diff. peak
1.563 and -0.762
0.795 and -0.534
and hole (e Å-3
largest diff. peak
and hole (e Å-3
)
1.563 and -0.762
0.795 and -0.534
)
with ketones and the transmetalation of imino ligands from
silver or gold imino complexes to iridium chloro complexes.
(1) Synthesis of Methylamino Iridium(III) Complexes
and their Reactions with Ketones. In contrast with the many
methylamino complexes described for transition elements,
only two iridium derivatives have been reported, namely
[Ir{C,C-C4(CO2Me)4}H(NH2Me)(PPh3)2]19 and [Ir(dCHd
CdCH2)Cl(CO)(NH2Me)(PPh3)2]20 prepared by reacting the
appropriate precursors with MeNH2.
[Ir(Cp*)Cl(µ-Cl)]2 reacts with MeNH2 and MOTf (M )
Ag, Tl) (1:6:4, in CH2Cl2) to give a mixture of
[Ir(Cp*)(NH2Me)3](OTf)2 (3) and [Ir(Cp*)Cl(NH2Me)2]OTf
that we could not separate. However, 3 was obtained in
almost quantitative yield by reacting [Ir(Cp*)Cl(µ-Cl)]2 with
[Ag(NH2Me)2]OTf15 (1:4, in acetone). When solutions of 3
were stirred in acetone for 4 h, at room or refluxing
temperature, mixtures formed that we could not separate.
Their 1H NMR spectra, showed the presence of 3 and other
unidentified species.
On reaction of [Ir(Cp*)Cl(µ-Cl)]2 with MeNH2 in a 1:2
molar ratio in CH2Cl2, the amino complex [Ir(Cp*)Cl2-
(NH2Me)] (1) was prepared (Scheme 1). Complex 1 was also
obtained using acetone as solvent and was recovered
unchanged after refluxing it in acetone for 6 h. Complex
[Ir(Cp*)Cl(NH2Me)2]Cl (2a) precipitated almost quantita-
tively in CH2Cl2 only when an excess of the amine (8:1)
was used because, otherwise, it forms along with a small
amount of 1. The reaction of 2a with an excess of
NaClO4 · H2O in THF allowed the synthesis of [Ir(Cp*)-
Cl(NH2Me)2]ClO4 (2b). Like 1, complexes 2 do not react
with acetone at room temperature, although 2b converts into
an (imino)amino (Me-imam) complex through an aldol-like
reaction after refluxing it in acetone for 7 h (see below).
This contrasts with the behavior of the Rh homologue
[Rh(Cp*)Cl(NH2Me)2]ClO4, which converts into the corre-
sponding Me-imam derivative upon stirring it in acetone at
room or refluxing temperature for 24 or 2 h, respectively.15
This difference proves that the metal plays a key role in the
aldol-like reaction and that the more inert nature of the Ir
metal center is responsible for the slow down of the reaction.
When suspensions of 1 or 2a in MeC(O)Ph were stirred
at room or refluxing temperature, formation of [Ir(Cp*)Cl(µ-
Cl)]2 took place with MeNH2 loss. Complex 3 was recovered
unchanged upon stirring it in MeC(O)Ph for 24 h at room
temperature. However, when it was heated in a small volume
of MeC(O)Ph at 80 °C for 4 h, the orthometallated complex
[Ir(Cp*){C,N-C6H4{C(Me)dN(Me)}-2}(NH2Me)]OTf (4)
formed along with [MeNH3]OTf. Complex 4 results from
the condensation reaction of one of the amino ligands in 3
with acetophenone and orthometalation of the phenyl group.
These reactions with acetophenone parallel those of their
homologue rhodium complexes, previously reported by us.15
t
Complex 4 does not react with RNC (R ) Bu, Xy) at
room temperature, even if a large excess of isocyanide is
used.However,complexes[Ir(Cp*){C,N-C6H4{C(Me)dN(Me)}-
t
2}(CNR)]OTf [R ) Bu (5), Xy (6)] can be obtained by
refluxing a mixture of 4 and the isocyanide (1:6 or 1:1.5,
respectively, in CHCl3, 5 h). The result of these reactions
do not change if a larger excess of isocyanide is used (1:12)
and the refluxing is prolonged for 24 h which is a difference
with respect to its homologue rhodium complex (R ) Xy)
which, under the same reaction conditions inserts isocyanide
(19) O′Connor, J. M.; Pu, L.; Rheingold, A. L. J. Am. Chem. Soc. 1990,
112, 6232.
(20) Chen, J.-T.; Chen, Y.-K.; Chu, J.-B.; Lee, G.-H.; Wang, Y. Organo-
metallics 1997, 16, 1476.
9598 Inorganic Chemistry, Vol. 47, No. 20, 2008

Synthesis and ReactiWity of Ir(I) and Ir(III) Complexes
Scheme 2
the solid state. In an attempt to prepare [Ir(CO)2{N-
(Me)dCMe2}2]OTf, we bubbled CO through a solution of
8 in CH2Cl2 but, in this case, massive decomposition was
observed.
The reaction of 7 or 8 with Me4NCl (1:1.1) produces the
substitution of one imino ligand by chloro to give the neutral
mono(imino) derivative [IrCl{N(R)dCMe2}(COD)] [R ) H
(10) or Me (11), respectively] (Scheme 2). When PPNCl or
Bu4NCl were used instead of Me4NCl, complex 10 or 11
could not be separated from the corresponding ammonium
perchlorate even after repeated recrystallizations.
When [Ir(Cp*)Cl(µ-Cl)]2 was reacted with [Au(NHd
CMe2)(PPh3)]ClO410 (1:2, in CH2Cl2), quantitative precipita-
tion of [Ir(Cp*)(µ-Cl)(NHdCMe2)]2(ClO4)2 (12) occurred.
The soluble byproduct, [AuCl(PPh3)], was removed by
filtration (Scheme 3). The homologous Rh(III) complex was
prepared by the same method,13 and both syntheses support
our10,12,13,24 and others’25 previous observations on the utility
of gold(I) complexes as transmetallating agents. The reaction
of 12 with PPh3 or Me4NCl in 1:2 molar ratio produces
complexes [Ir(Cp*)Cl(NHdCMe2)(PPh3)]ClO4 (13) or
[Ir(Cp*)Cl2(NHdCMe2)] (14), respectively. In an attempt
to get single crystals of 14 by the liquid diffusion method,
using CH2Cl2 and Et2O, orange crystals of the hydrolysis
product [Ir(Cp*)Cl2(NH3)] (15) grew instead.
The reaction of [Ir(Cp*)Cl(µ-Cl)]2 with [Ag(NHd
CMe2)2]ClO4 (1:4) gives [Ir(Cp*)(NHdCMe2)3](ClO4)2
(16a). When a 1:2 molar ratio of the same reagents was used,
a mixture formed of the expected bis(imino) complex
[Ir(Cp*)Cl(NHdCMe2)2]ClO4 (17) and (16a) that we could
not separate. The analogous reaction with the corresponding
rhodium complex gave only the Rh analog of 17.13 The
attempt to prepare 17 by reaction of 16a with PPNCl
produces instead the substitution of one perchlorate coun-
teranion by chloride to give [Ir(Cp*)(NHdCMe2)3]Cl(ClO4)
(16b) which precipitated in the reaction mixture. This
behavior contrasts with that of the rhodium analog
[Rh(Cp*)(NHdCMe2)3](ClO4)2, which reacts with PPNCl to
give an H-imam complex13 resulting from the aldol-like
condensation of two imino ligands. In an attempt to grow
single crystals of 16b by slow diffusion of an acetone
solution of 16a through another of PPNCl in the same
solvent, crystals of [Ir(Cp*)(NHdCMe2)3]Cl2 (16c) grew
instead, which were used for an X-ray diffraction study.
into the Rh-Caryl bond to give the imino(iminoacyl) complex
[Rh(Cp*){C,N-C(dNXy)C6H4{C(Me)dN(Me)}-2}(CNXy)]OTf.15
Apart from our [Rh(Cp*){C,N-C6H4{C(Me)dN(Me)}-
2}(NH2Me)]OTf,15and[Sm(Cp*)2{C,N-C6H4{C(Me)CdN(Me)}-
2],21 no complex of any metal with this orthometallated imino
ligand has been reported so far in spite of the existence of a
large number of complexes derived from the orthometalation
of arylimino ligands, many of them structurally characterized
by X-ray crystallography.22 The related complexes [Ir-
(C•N)2Cl]2 and [Ir(C•N)2(R-acac)] [C•N ) C,N-C6H3{C(Me)-
CdN(Me)}-2-tBu-5, R-acac ) O,O′-OC(Me)CHC(O){(CH2)2-
C6H4CHdCH2-4}] have been used to prepare polymers with
interesting optical properties.23 The samarium complex and
its halogenated (X ) H, Cl, Br) derivatives [Sm(Cp*)2{C,N-
C6H3{{C(Me)CdN(Me)}-2}X-4] were obtained by reacting
[Sm(Cp*)2H]2withtheappropriateimineC6H3{C(Me)CdN(Me)}-
2,X-4 in a process producing H2 evolution.
(2) Synthesis of Imino Iridium Complexes by
Transmetalation Reactions. On the basis of our previous
experience on the ability of silver and gold complexes
[Ag{N(R)dCMe2}2]X (R ) H, X ) ClO4; R ) Me, X )
ClO4, OTf)8,15 and [Au{N(R)dCMe2}PPh3]X (R ) H, X )
ClO4; R )Me, X ) OTf),10 to act as efficient transmetallating
agents toward chloro complexes of Rh(I),8 Rh(III),13,14 and
Pt(II),12 we decided to extend this method to the synthesis
of [Ir]{N(R)dCMe2} complexes.
The reaction of the appropriate [Ag{N(R)dCMe2}2]X
complex and [Ir(µ-Cl)(COD)]2 in 2:1 molar ratio, allowed
the syntheses of complexes [Ir{N(R)dCMe2}2(COD)]X (R
) H, X ) ClO4 (7); R ) Me, X ) OTf (8)) in good yields
(Scheme 2). 8 was also obtained directly from AgOTf,
MeNH2, and [IrCl(COD)]2 (2:4:1) in acetone. The reaction
of 7 with excess CO produces the replacement of COD to
give cis-[Ir(CO)2(NHdCMe2)2]ClO4 (9) which is stable in
solution under a CO atmosphere but decomposes slowly in
(24) (a) Vicente, J.; Chicote, M. T.; Abrisqueta, M. D.; Jones, P. G.
Organometallics 1997, 16, 5628. (b) Vicente, J.; Chicote, M. T.;
Abrisqueta, M. D. J. Chem. Soc., Dalton Trans. 1995, 497. (c) Vicente,
J.; Chicote, M. T.; Abrisqueta, M. D.; Alvarez-Falco´n, M. M. J.
Organomet. Chem. 2002, 663, 40. (d) Vicente, J.; Chicote, M. T.;
Jones, P. G. Inorg. Chem. 1993, 32, 4960.
(25) (a) Singh, A.; Sharp, P. R. Dalton Trans. 2005, 2080. (b) Bruce, M. I.;
Humphrey, P. A.; Melino, G.; Skelton, B. W.; White, A. H.; Zaitseva,
N. N. Inorg. Chim. Acta 2005, 358, 1453. (c) Contel, M.; Stol, M.;
Casado, M. A.; van Klink, G. P. M.; Ellis, D. D.; Spek, A. L.; van
Koten, G. Organometallics 2002, 21, 4556. (d) Ferrer, M.; Rodr´ıguez,
L.; Rossell, O.; Lima, J. C.; Go´mez-Sal, P.; Mart´ın, A. Organometallics
2004, 23, 5096. (e) Gregory, J.; Ingold, C. K. J. Chem. Soc. B 1969,
276. (f) Bennett, M. A.; Bhargava, S. K.; Griffiths, K. D.; Robertson,
G. B.; Wickramasinghe, W. A.; Willis, A. C. Angew. Chem., Int. Ed.
Engl. 1987, 26, 258.
(21) Radu, N.; Buchwald, S. L.; Scott, B.; Burns, C. J. Organometallics
1996, 15, 3913.
(22) Cambridge Structural Database, version 5.29; Cambridge Crystal-
lographic Data Centre: Cambridge, U.K., November 2007; www.
ccdc.cam.ac.uk.
(23) Otsubo, A.; Takahashi, Y. Jpn. Kokai Tokkyo Koho 2007, CAN 147:
265388.
Inorganic Chemistry, Vol. 47, No. 20, 2008 9599

Vicente et al.
Scheme 3
Scheme 4
The synthesis of the bis(imino)complex 17 was achieved
expected complexes [Ir(Cp*)Cl2{N(Me)dCMe2}] (A) and
[Ir(Cp*)Cl{N(Me)dCMe2}2]ClO4 (B) that are unstable.
Hydrolysis of the imino ligand in A would account for the
formation of 1, while 19 would form upon the aldol-like
condensation of the two imino ligands in B.
(3) Imam Complexes. In an attempt to prepare [Ir(Cp*)Cl2-
(NHdCMe2)] by reacting [Ir(Cp*)Cl(NHdCMe2)2]ClO4 (17)
with PPNCl (1:1, in acetone), a suspension of the complex
by refluxing in CH2Cl2, for 24 h, a mixture containing
equimolar amounts of the mono- and tris(imino) derivatives
14 and 16a, respectively (Scheme 3). When acetone was used
instead, condensation processes of the acetimino ligands took
place, as we will discuss below.
We have made different unsuccessful attempts to prepare
Ir(III) complexes with the Me2CdNMe ligand by transmeta-
lation reactions. Thus [Ir(Cp*)Cl(µ-Cl)]2 was reacted in
acetone under nitrogen with [Ag{N(Me)dCMe2}2]ClO4 in
1:4 or 1:2 molar ratio to produce, respectively, massive
decomposition or mixtures in which [Ir(Cp*)Cl2(NH2Me)]
(1), [Ir(Cp*)Cl(Me-imam)]ClO4 (19, Me-imam ) N,N′-
N(Me)dC(Me)CH2C(Me)2NHMe, see below), and Me2C-
[Ir(Cp*)Cl(H-imam)]Cl (18a, H-imam
) N,N′-NHd
C(Me)CH2C(Me)2NH2), resulting from the aldol-like con-
densation of two acetimino ligands, was obtained (Scheme
4). The homologue [Ir(Cp*)Cl(H-imam)]ClO4 (18b) was
isolated in almost quantitative yield by reacting 18a with
NaClO4·H2O (1:1, acetone, 30 min). Complexes of Rh
homologous of 18a, b have been prepared by us using the
same method,13 although Rh and Ir acetimino complexes
differ in other aspects. Thus, the reaction of PPNCl with
[M(Cp*)(NHdCMe2)3](ClO4)2 (1:1, in acetone) gives, when
M ) Rh, [Rh(Cp*)Cl(H-imam)]ClO4, while when M ) Ir
(16a), it produces the substitution of one perchlorate anion
1
(OH)CH2C(O)Me were identified by H NMR. When the
same iridium complex was reacted with [Au{(N(Me)d
CMe2)}(PPh3)]ClO4 (1:2, in acetone, under nitrogen) a
mixture was obtained of [AuCl(PPh3)] (identified by 31P
NMR) along with 1 and 19. These results suggest that the
transmetalation reactions effectively occur producing the
9600 Inorganic Chemistry, Vol. 47, No. 20, 2008

Synthesis and ReactiWity of Ir(I) and Ir(III) Complexes
by chloride to give 16b, as we have mentioned above. After
refluxing a suspension of 16b in acetone, [Ir(Cp*)Cl(H-
imam)]ClO4 (18b) formed as the result of substitution of one
acetimino ligand by the chloride counterion and the con-
densation of two acetimino ligands. On the other hand,
[Rh(Cp*)Cl(NHdCMe2)2]ClO4 remains unchanged after stir-
ring it in acetone at room temperature for 24 h and converts
into [Rh(Cp*)Cl(H-imam)]ClO4 when it is stirred in acetone
for 24 h under a CO atmosphere (1.8 bar), or is treated with
a catalytic amount of Ph2CdNH (1:0.1) or SMe2 (1:0.1), or
when it is reacted with the equimolar amount of AsPh3 in
acetone, or when it is heated at 70 °C in solution (CH2Cl2
or acetone, in a Carius tube) for 24 h.15 However, none of
these reactions work the same way when starting from its
homologue iridium complex 17, which was recovered
unchanged after refluxing it in acetone for 24 h, does not
react with CO (3 days) or reacts with AsPh3 to give a mixture
containing 17 and 18b among other products that we could
not identify.
When an acetone solution of [Ir(Cp*)Cl(NH2Me)2]ClO4
(2b) was refluxed in acetone for 7 h, with the purpose of
preparing [Ir(Cp*)Cl{N(Me)dCMe2}2]ClO4, the complex
[Ir(Cp*)Cl(Me-imam)]ClO4 (19) formed instead and was
isolated in 91% yield. The reaction is likely to occur through
the expected bis(imino) complex that would be unstable
toward the intramolecular 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 acetimine [Ir(Cp*)Cl(NHdCMe2)2]ClO4
(17) that could be isolated and is stable in acetone solution
for 24 h at room temperature.
Figure 1. Thermal ellipsoid representation plot (50% probability) of 15.
Me hydrogens are omitted for clarity. Selected bond lengths (Å) and angles
(deg): Ir(1)-C(11) 2.165(3), Ir(1)-C(12) 2.133(3), Ir(1)-C(13) 2.122(3),
Ir(1)-C(14) 2.139(3), Ir(1)-C(15) 2.164(3), Ir(1)-N(1) 2.127(3), Ir(1)-Cl(2)
2.4271(8),Ir(1)-Cl(3)2.4289(8),N(1)-Ir(1)-Cl(2)83.73(9),N(1)-Ir(1)-Cl(3)
82.76(9), Cl(2)-Ir(1)-Cl(3) 88.55(3).
In all previous reports on the formation of H-imam
complexes,26 the ligand forms from the condensation of
acetone or mesityl oxide with ammonia in a base assisted
template reaction. The formation of 18a and its Rh analogue
shows for the first time that the H-imam ligand can also form
by intramolecular aldol-type condensation of two acetimino
ligands, and a reasonable mechanism for this process has
been previously proposed by us.15
Complexes [Ir(Cp*)Cl(R-imam)]ClO4 react with AgClO4
and the appropriate neutral ligand or with [Ag(NHd
CMe2)2]ClO4 to give [Ir(Cp*)(R-imam)L](ClO4)2 [R ) H,
L ) tBuNC (20), XyNC (21); R ) Me, L ) MeCN (22)] or
[Ir(Cp*)(H-imam)(NHdCMe2)](ClO4)2 (23a), respectively
(Scheme 4).
We reacted 23a with PPNCl in acetone with the purpose
of exploring if a second aldol-like condensation process could
take place to give a complex with a tridentate mixed-imam
ligand. However, substitution of one of the perchlorate
anions by chloride took place to give [Ir(Cp*)(H-
imam)(NHdCMe2)]Cl(ClO4) (23b). When a suspension of
this complex was refluxed in acetone for 24 h, the imino
ligand was replaced by the chloride counterion to give 18b.
Figure 2. Thermal ellipsoid representation plot (30% probability) of the
cation of complex 16c. Me hydrogens are omitted for clarity. Selected bond
lengths (Å) and angles (deg): Ir(1)-C(11) 2.188(2), Ir(1)-C(12) 2.187(2),
Ir(1)-C(13) 2.183(2), Ir(1)-C(14) 2.179(2), Ir(1)-C(15) 2.155(2), Ir(1)-N(1)
2.085(2), Ir(1)-N(2) 2.092(2), Ir(1)-N(3) 2.110(2), N(1)-C(2) 1.273(4),
N(2)-C(5) 1.272(3), N(3)-C(8) 1.279(3), N(1)-Ir(1)-N(2) 82.60(8),
N(1)-Ir(1)-N(3) 87.83(8), N(2)-Ir(1)-N(3) 88.21(8).
The reaction of [Ir(Cp*)(Me-imam)(NCMe)](ClO4)2 (22)
with XyNC produced the replacement of the labile MeCN
ligand to give [Ir(Cp*)(Me-imam)(CNXy)](ClO4)2 (24).
X-ray Crystal Structures. The crystal structures of 15
(Figure 1, Table 1) and 16c (Figure 2, Table 1) have been
solved by X-ray diffraction methods and show the iridium
atom in a pseudo-octahedral “three-legged piano stool”
environment, with the Cp ligand occupying three fac
coordination sites. Although the structure of 18b (Figure 3)
(26) (a) Curtis, N. F. Coord. Chem. ReV. 1968, 3, 3. (b) Curtis, N. F.;
Powell, H. K. J.; Puschmann, H.; Rickard, C. E. F.; Waters, J. M.
Inorg. Chim. Acta 2003, 355, 25.
Inorganic Chemistry, Vol. 47, No. 20, 2008 9601

Vicente et al.
angles, while the two shortest ones (2.122(3) and 2.133(3)
Å) correspond to CCp*-Ir-N angles of 95.43(12) and
110.61(13)°, that is, to Ctrans to Cl-Ir-N angles. These data
suggest that the trans influence of chloro is slightly smaller
than that of NH3. In dicationic 16c, the Ir-CCp* bond
distances are longer (2.155(2)-2.188(2) Å) than in 15
(2.122(3)-2.165(3) Å), probably because of the decrease of
π back-bonding.
Spectroscopic Properties. The 1H NMR spectra of
complexes containing MeNH2 ligands (1-4) show the Me
protons as a triplet in the interval 2.16-2.77 ppm with 3JHH
coupling constants of 6-7 Hz. As expected, complexes 1
and 3 show only one broad28 NH resonance at 3.65 and 4.93
ppm, respectively, while in the spectrum of 2a two NH
resonances are observed, at 5.02 and 5.14 ppm. In complex
2b, both appear together at 4.63 ppm as a broad resonance
while in 4 they must be so broad that they cannot be
observed. The deshielding of the NH2 protons in 2a with
respect to those in 2b suggests the existence of some
N-H · · · Cl interaction in the former. The 13C{1H} NMR
spectra of complexes 1-3 show one NMe resonance
(32.8-34.0 ppm). A broad resonance at 3.19 ppm is observed
in the 1H NMR spectrum of 15 because of the NH3 protons.
In the NMR spectra of complexes 4-6, containing a
chelating acetophenone-N-methylimino orthometallated ligand,
the resonances due to the NMe (3.90-3.98 (1H), 146.2-48.7
(13C) ppm), C-Me (2.56-2.66 (1H), 15.1-15.7 (13C) ppm)
and C)N (183.7-185.3 ppm) fragments are in the same
regions as in their rhodium homologues.15
Figure 3. Unrefined structure of the cation in 18b showing the atom
connectivity. Figures 4 and 5 show the various hydrogen bonds present in
15 and 16c.
The 1H NMR spectrum of free acetimine (in acetonitrile-
d3) has been reported2 to show one singlet for both Me
groups while the NH resonance seems to be absent. With
the only exception of 16b, all the acetimino complexes show
one NH (8.99-11.56 ppm), two Me (1H: 1.83-2.54, 13C:
25.7-30.5 ppm) and one C)N (183.2-193.2 ppm) reso-
nances as expected for mono(imino) (10, 13, 14, 23)
complexes or some bis- (7, 9, 12) or tris(imino) (16a, c)
1
derivatives. In some cases, the coupling between the H
resonance of the Me group trans to the NH proton is observed
(0.9 < 4JHH < 1.4 Hz; 13, 14, 16a, 17, 23a); in addition, in
16a the cis coupling is also observed (4JHH ) 0.6 Hz). Similar
couplings have been previously observed in acetimino
complexes of rhodium,13 gold,9,10 or platinum.12 In contrast
Figure 4. (a) Zig-zag ribbons along the a axis in complex 15 formed by
intermolecular N-H· · ·Cl interactions. (b) Two-ribbon interactions formed
by C-HMe · · ·Cl contacts. Only the two CH groups involved in these contacts
are represented. (c) View of the layers.
could not be refined, the atom connectivity in the cation was
established unequivocally.
1
to the H NMR spectrum of 16a, which is temperature
independent, we have found that each of the resonances
observed in the room temperature spectrum of 16b splits into
two signals of 2:1 relative intensities when it is measured at
-58 °C (in dmf-d7, see Experimental Section) showing that
one of the imino ligands is inequivalent to the two others
probably because of its participation in a N-H· · ·Cl bonding.
The C)N carbon nuclei are more shielded when the
remaining ligands are less electron-withdrawing. This is
In 15, the Ir-N and Ir-Cl bond distances are similar to
those found in the only two other “Ir(Cp*)(NH3)2+” com-
plexes structurally characterized.22,27 The CdN bond dis-
tances in 16c are similar to those found in other acetimino
complexes (range 1.271(7)-1.285(4) Å)8,10,12,13,15 regardless
of the nature of the metal ions, its formal oxidation state,
the charge of the complex, or the other ligands. The Ir-N
bond distances in 16c are similar to those found in the only
two other structurally characterized complexes bearing the
Ir(Cp*)NHdC fragment, none of which contain an acetimino
ligand.22
(27) (a) Rais, D.; Bergman, R. G. Chem.sEur. J. 2004, 10, 3970. (b)
Hughes, R. P.; Smith, J. M.; Incarvito, C. D.; Lam, K. C.; Rhatigan,
B.; Rheingold, A. L. Organometallics 2002, 21, 2136. (c) Hughes,
R. P.; Smith, J. M.; Incarvito, C. D.; Lam, K. C.; Rhatigan, B.;
Rheingold, A. L. Organometallics 2004, 23, 3362.
(28) Gu¨nter, H. NMR Spectroscopy. An Introduction; John Wiley & Sons:
New York, 1980.
The longest Ir-CCp* bond distances in 15 (2.164(3) and
2.165(3) Å) correspond to the widest CCp*-Ir-N angles
(149.39(13) and 155.02(13)°), that is, to Ctrans N-Ir-N
to
9602 Inorganic Chemistry, Vol. 47, No. 20, 2008

Synthesis and ReactiWity of Ir(I) and Ir(III) Complexes
Figure 5. Formation of dimers (a) and chains (b) via C-H· · ·Cl and N-H· · ·Cl contacts between cations and chloride anions in 16c. (c) View showing
contacts between dimers to give a 3D framework.
Chart 2. Isomers of Complex 8
observed when complex 7 (L2 ) cyclooctadiene, 184.5 ppm)
or 14 (L ) L′ ) Cl, 184.4 ppm) is compared with its
homologue 9 (L ) CO, 193.4 ppm) or 13 (L ) Cl, L′ )
PPh3, 190.1 ppm), respectively.
29
1
The H NMR spectrum of the free imine Me2CdNMe
shows three signals of 1:1:1 relative intensities. The reso-
nances of the Me groups in cis- or trans- to the NMe group
appear as quartets (1.80 ppm, 5JHH ) 0.7 Hz; 1.98 ppm, 5JHH
)1.3 Hz, respectively) while the NMe protons give a
resonances indicating that the activation barrier for the
isomerization process is exceeded at that temperature.
The H NMR spectra of the R-imam complexes 18-24
1
multiplet at 3.06 ppm. However, in the H NMR spectra of
complexes 8 and 11, the three Me resonances are singlets.
The NMe nuclei (1H: 3.32-3.48; 13C: 42.5-43.7 ppm) are,
as in the free imine, less shielded than the CMe2 ones
(2.04-2.11, 2.69-2.93 (1H) or 22.2-22.6, 30.7-31.6 (13C)
ppm). The NMR spectra of 11 show the expected resonances
for the imino ligand (2.04, 2.69, 3.32 (1H), 22.2, 30.7, 42.5,
175.3 (13C) ppm). However, the 13C NMR spectrum shows
four resonances for the methylenic (30.8, 31.0, 31.9, 32.3
ppm) and for the olefinic (57.2, 57.3, 68.4, 68.9 ppm)
cyclooctadiene carbons which means that the Me2CdNMe
ligand is out of the metal coordination plane, trying to
minimize its repulsion with the chloro ligand. As this must
also be the case for both imino ligands in 8, two isomers,
syn and anti (Chart 2), have to be observed in its NMR
1
show the protons of Me5 (Chart 1), bonded to a sp2 carbon
(2.36-2.62 ppm), less shielded than those of Me6 and Me7
(0.90-1.36, 1.21-1.58 ppm, respectively), both attached to
a sp3 carbon, and the same trend is observed in the 13C NMR
spectra (24.9-31.0 (Me5), 19.2-25.9 and 24.0-29.3 ppm).
The proton resonances are singlet except those of Me5 in
18b, 20, and 23a which are doublet due to coupling to the
NH proton (4JHH 1-3 Hz). The CH2 protons give two
doublets (19, 22-24) or an AB system (in the interval
2
1.77-3.91 ppm, JHH 13-18 Hz) except in complexes 18
where they are isocronous (18b, 2.63 ppm) or resonate very
close to each other (in 18a, only the central resonances of
the expected AB system are observed at 2.40 and 2.42 ppm).
The resonances due to the Me4 nuclei (3.64-3.92 (1H),
47.3-52.6 (13C) ppm) and C1 (183.0-189.6 ppm), both
bonded to the iminic nitrogen, are considerably less shielded
than those of Me8 (2.79-2.97 (1H), 36.9-43.2 (13C) ppm)
and C3 (47.3-60.3 ppm) bonded to the aminic nitrogen,
respectively.
1
spectra. In fact, both the imino and cyclooctadiene H and
13C NMR resonances are duplicated in 8. As one of the
isomers is more abundant than the other (2.25:1) we could
assign the resonances of both isomers except when they
coincide accidentally. We tentatively assign the more intense
resonances to the anti isomer which is less crowded. A VT
1H NMR study shows that at 10 °C one of the Me resonances
In the H-imam complexes, the inequivalent NH2 protons
5
of the major isomer splits into a quartet (at 2.93 ppm, JHH
2
give two doublets (4.21-5.32, 5.21-6.19 ppm; JHH 9-12
) 1 Hz) while at 50 °C the spectrum shows only one set of
Hz) with the exception of 18b which shows two very broad
(29) Nelson, D. A.; Atkins, R. Tetrahedron Lett. 1967, 51, 5197.
resonances. The iminic NH proton gives a broad signal
Inorganic Chemistry, Vol. 47, No. 20, 2008 9603

Vicente et al.
(10.1-11.5 ppm) in the same region where the NH appears
in the acetimino complexes. In the Me-imam complexes the
aminic NH resonance (3.70-6.34 ppm) is generally broad,
although in the spectrum of one of the isomers of 24 it is a
quartet due to coupling to the Me8 protons (3JHH ) 5 Hz).
Additionally, Me-imam complexes 19, 22, and 24 contain
two chiral centers, and all the resonances of the RR+SS and
RS+SR diastereoisomers could be assigned since they are
in different molar ratios (see Experimental Section).
The MeCp* (1.5-2.1 (1H), 8.2-9.2 (13C) ppm) and the
C5Me5 (84.8-97.4 ppm) nuclei give singlet resonances. The
position of the latter seems not to depend on the charge of
the complex since neutral complexes 1 or 14 compared to
cationic 2a or 17, respectively, give similar δ values (85-88
ppm). Replacement of Cl in 14 by PPh3 to give 13 causes
the deshielding of the quaternary Cp* carbon nuclei from
85.6 to 94.2 ppm, which can be attributed to the change of
a π-donor by a π-acceptor ligand. The high δ values
(94.8-97.4 ppm) found in complexes bearing a RNC ligand,
show that isocyanides act mainly as σ-donor ligands.
The NMR spectra of complex 8 shows the above-
mentioned four )CH (3.59, 3.66, 3.78, 3.80 (1H), 65.9, 66.6,
67.2, 67.7 (13C) ppm) and CH2 (two extended multiplets
1.48-1.83 and 2.19-2.43 (1H), 30.7, 31.0, 31.1, 31.2 (13C)
ppm) resonances and duplicated CMe2 and NMe resonances,
which requires the existence ot two isomers in solution. This
behavior is not observed in complex 7 because the smaller
nitrogen substituent (H vs Me) allows the free rotation of
the imino ligand around the Ir-N bond.
effect has also been observed when comparing the 31P NMR
spectra of homologous Pd and Pt complexes36 and has been
attributed to stronger Pt-P than Pd-P bonds.
The IR spectrum of the carbonyl complex 9 (C2V) shows
two ν(CO) bands at 2078 and 2009 cm-1, shifted by some
20 cm-1 toward lower energy with respect to those in the
homologous Rh complex (at 2092 and 2026 cm-1),8 which
must be due to a slightly greater π-donor character of Ir. A
strong absorption is observed in the spectra of the isocyanide
complexes in the 2132-2206 cm-1 assignable to the ν(CtN)
stretching mode. Only one such band is observed for the
two diastereoisomers of 24, as it occurs in its Rh homo-
logue.15 None of the two expected ν(CtN) bands is observed
in the acetonitrilo complex 22 in spite of the fact that its
rhodium homologue shows two weak absorptions at 2136
and 2288 cm-1. Bands due to the counteranion are observed
in the spectra of cationic complexes at around 1100 and 620
(ClO4 ) cm-1 or in the 1150-1370 cm-1 (OTf) region.
-
Conclusion
We have prepared the first family of Ir(III) methylamino
complexes including a neutral and the first mono- and
dicationic species with the purpose of reacting them with
ketones to prepare the first iridium methylimino complexes.
The reactions of the neutral complex with acetone did not
take place but, after refluxing an acetone solution of the
monocationic complex [Ir(Cp*)Cl(NH2Me)2]+ an (imino)am-
ino (Me-imam) complex was obtained. This contrasts with
the behavior of its Rh homologue, which converts into the
corresponding Me-imam derivative at room temperature. The
Me-imam Ir complex must be the result of an aldol-like
condensation reaction from the nonisolated methylimino
complex [Ir(Cp*)Cl{N(Me)dCMe2}2]+. The dicationic meth-
ylamino complex [Ir(Cp*)(NH2Me)3]2+ reacts with acetone
to give an unidentified mixture of products but with ac-
etophenone one of the few orthometallated complexes of the
corresponding imine was obtained. Transmetalation reactions
using acetimino or methyl acetimino Ag(I) or Au(I) com-
plexes and chloro Ir(I) or Ir(III) complexes have allowed us
to prepare the first imino complexes [Ir]{N(R)dCMe2} (R
) H, Me), except for [Ir(III)]{N(Me)dCMe2}, which at-
tempted syntheses always afforded mixtures of products or
Me-imam complexes. This is a difference with respect to
the chemistry of methylimino complexes of Rh(III). A family
of H-imam Ir(III) complexes has been prepared from the
The CtN resonance is not observed in any of the
isocyanide complexes here described, as is also the case in
other isocyanide complexes previously reported.30
Complexes of rhodium homologues of 1-7, 9, 12, 13,
16-19, and 21-24 have been previously reported by
us.8,13,15 When their NMR spetra are compared, it becomes
apparent that the resonances due to carbon or phosphorus
nuclei directly bonded to the metal are considerably shielded
in the iridium complexes compared to the rhodium ones
likely because of the stronger Ir-C or Ir-P bonds. In fact,
the quaternary C5Me5 (1-6, 12-24), CO (9), CHdCH (7,
8, 10, 11), or Caryl (4-6) 13C NMR resonances or the 31P
resonance in 13 appear at 84.8-97.4, 171.5, 57.2-70.0,
154.6-164.7 or 8.9 ppm, respectively, the mean shielding
with respect to their Rh homologues being of 7, 12, 15, 17,
or 27 ppm, respectively. Similar chemical shift differences
can be found in previously reported Rh/Ir couples of
homologous complexes with Cp*-,31,32 CO-,33 cyclooctadi-
ene,34 aryl-,32 or P-donor35 ligands although, as far as we
are aware, this observation has not been accounted for. This
(33) (a) Elgafi, S.; Field, L. D.; Messerle, B. A.; Turner, P.; Hambley, T. W.
J. Organomet. Chem. 1999, 588, 69. (b) Field, L. D.; Messerle, B. A.;
Rehr, M.; Soler, L. P.; Hambley, T. W. Organometallics 2003, 22,
2387. (c) Boyd, S. E.; Field, L. D.; Hambley, T. W.; Partridge, M. G.
Organometallics 1993, 12, 1720.
(34) Landaeta, V. R.; Peruzzini, M.; Herrera, V.; Bianchini, C.; Sa´nchez-
Delgado, R. A.; Goeta, A. E.; Zanobini, F. J. Organomet. Chem. 2006,
691, 1039.
(35) (a) Carmona, D.; Lahoz, F. J.; Elipe, S.; Oro, L. A.; Lamata, M. P.;
Viguri, F.; Sa´nchez, F.; Mart´ınez, S.; Cativiela, C.; Lo´pez-Ram de
V´ıu, M. P. Organometallics 2002, 21, 5100. (b) Vicente, J.; Abad,
J. A.; Lahoz, F. J.; Plou, F. J. J. Chem. Soc., Dalton Trans. 1990,
1459.
(36) (a) Vicente, J.; Chicote, M. T.; Huertas, S.; Bautista, D.; Jones, P. G.;
Fischer, A. K. Inorg. Chem. 2001, 40, 2051. (b) Vicente, J.; Chicote,
M. T.; Huertas, S.; Jones, P. G.; Fischer, A. K. Inorg. Chem. 2001,
40, 6193.
(30) (a) Vicente, J.; Gil-Rubio, J.; Guerrero-Leal, J.; Bautista, D. Orga-
nometallics 2005, 24, 5634. (b) Vicente, J.; Gil-Rubio, J.; Guerrero-
Leal, J.; Bautista, D. Organometallics 2004, 23, 4871.
(31) (a) Koike, T.; Ikariya, T. Organometallics 2005, 24, 724. (b) Pettinari,
C.; Pettinari, R.; Marchetti, F.; Macchioni, A.; Zuccaccia, D.; Skelton,
B. W.; White, A. H. Inorg. Chem. 2007, 46, 896. (c) Pettinari, C.;
Pettinari, R.; Fianchini, M.; Marchetti, F.; Skelton, B. W.; White, A. H.
Inorg. Chem. 2005, 44, 7933.
(32) Davies, D. L.; Al-Duaij, O.; Fawcett, J.; Giardiello, M.; Hilton, S. T.;
Russell, D. R. Dalton Trans. 2003, 4132.
9604 Inorganic Chemistry, Vol. 47, No. 20, 2008

Synthesis and ReactiWity of Ir(I) and Ir(III) Complexes
corresponding bis- or tris-acetimino complexes or by reacting
these products with various ligands.
Regio´n de Murcia 2007-2010, Grant 02992/PI/05) for
financial support.
Supporting Information Available: Crystallographic files in
CIF format for compounds 15 and 16c. This material is available
free of charge via the Internet at http://pubs.acs.org.
Acknowledgment. We thank Direccio´n General de In-
vestigacio´n/FEDER (Grants CTQ2004-05396 and CTQ2007-
60808/BQU, C-Consolider) and Fundacio´n Se´neca (Ayudas
a los Grupos y Unidades de Excelencia Cient´ıfica de la
IC801184V
Inorganic Chemistry, Vol. 47, No. 20, 2008 9605