Reactions of rhodium(II) and iridium(III) complexes bearing a P,O-coordination with tetracyanoethylene in the presence of KPF6

Article abstract of DOI:10.1016/j.ica.2004.04.014

Reactions of Cp*M(MDMPP-P,O)Cl (1a: M=Rh, 1b: M=Ir; MDMPP-P,O=PPh₂(2-O-6-MeOC₆H₃)) with tetracyanoethylene (tcne) in the presence of KPF₆ gave Cp*MCl[PPh₂{2-O-3-(C(CN)₂CH(CN)₂)-6- MeOC₆H₂}] (2), [{Cp*MPPh₂{2-O-3-(C(CN)= C(CN)₂)-6-MeOC₆H₂}}₂(CN)](PF ₆) (3), [{Cp*IrPPh₂{2-O-3-(C(CN)=C(CN) ₂)-6-MeOC₆H₂}}(CN){Cp*Ir(MDMPP-P,O)}] (PF₆) (4b) and [{Cp*Ir(MDMPP-P,O)}₂(CN)](PF ₆) (5b), depending on the reaction conditions. Reaction of 2 with KPF₆ or AgOTf in the absence and presence of xylyl isocyanide (XylNC) gave 3 or [Cp*MCl{PPh₂(2-O-3-(C(CN)₂-CH(CN) ₂)-6-MeOC₆H₂)}(XylNC)](OTf) (6). The structure of 3a (M=Rh) was confirmed by X-ray crystal analysis.

Full text of DOI:10.1016/j.ica.2004.04.014

Inorganica Chimica Acta 357 (2004) 2833–2840
www.elsevier.com/locate/ica
Reactions of rhodium(II) and iridium(III) complexes bearing a
P,O-coordination with tetracyanoethylene in the presence of KPF6
a,
a
b
b,1
Yasuhiro Yamamoto *, Asako Takahashi , Yusuke Sunada , Kazuyuki Tatsumi
a
Department of Chemistry, Faculty of Science, Toho University, Miyama, Funabashi, Chiba 274-8510, Japan
b
Research Center for Materials Science and Department of Chemistry, Graduate School of Science, Nagoya University, Furo-cho,
Chikusa-ku, Nagoya 454-8602, Japan
Received 2 December 2003; accepted 17 April 2004
Available online 15 June 2004
Abstract
Reactions of Cp*M(MDMPP-P,O)Cl (1a: M ¼ Rh, 1b: M ¼ Ir; MDMPP-P,O ¼ PPh2(2-O-6-MeOC6H3)) with tetracyanoethyl-
ene (tcne) in the presence of KPF6 gave Cp*MCl[PPh2{2-O-3-(C(CN)2CH(CN)2)-6-MeOC6H2}] (2), [{Cp*MPPh2{2-O-3-(C(CN)@
C(CN)2)-6-MeOC6H2}}2(CN)](PF6) (3), [{Cp*IrPPh2{2-O-3-(C(CN)@C(CN)2)-6-MeOC6H2}}(CN){Cp*Ir(MDMPP-P,O)}](PF6)
(4b) and [{Cp*Ir(MDMPP-P,O)}2(CN)](PF6) (5b), depending on the reaction conditions. Reaction of 2 with KPF6 or AgOTf in the
absence and presence of xylyl isocyanide (XylNC) gave 3 or [Cp*MCl{PPh2(2-O-3-(C(CN)2-CH(CN)2)-6-MeOC6H2)}(Xy-
lNC)](OTf) (6). The structure of 3a (M ¼ Rh) was confirmed by X-ray crystal analysis.
Ó 2004 Elsevier B.V. All rights reserved.
Keywords: Tetracyanoethylene; Pentamethylcyclopentadienyl; Rhodium(III); Iridium(III); C–CN bond cleavage
1. Introduction
positions have activated small molecules such as alkynes
and alkyl amines. For example, when complexes were
treated with 1-alkyne or disubstituted alkyne in the
presence of KPF6, novel single or double insertion of
alkyne into the Rh (or Ir)–O bond gave six- or seven-
membered metallacycles [5]. Reactions with tertiary or
secondary amines in the presence of KPF6 led to
cleavage of the C–N bond, generating the corresponding
primary alkyl amine complexes [6].
We have reported that the aforementioned complexes
were treated with electron-deficient olefins such as tcne
or 7,7,8,8-tetracyano-p-quinodimethane (tcnq), gener-
ating the complexes that the olefin inserted into weakly
activated C–H bonds on the phenyl ring of the phos-
phine ligand (Scheme 1) [7]. When they were treated
with an anion radical of 2,3,5,6-tetrafluoro-7,7,8,8-tet-
racyanoquinodimethane (F4-tcnq), spontaneous substi-
tution of the H atom adjacent to the metal–O bond with
the F4-tcnq anion radical and subsequent aromatization
of a quinodimethane ring occurred, followed by the final
formation of binuclear complexes by its dimerization
(Scheme 1) [8]. When these reactions were carried out in
the presence of KPF6 or AgOTf, we found an insertion
Tetracyanoethylene (tcne) affords a variety of charge
transfer and organometallic complexes as a result of its
strong electrophilicity [1]. Among them, the reactions
with metal–acetylide complexes are particularly interest-
ing: (i) insertion into M–C bonds [2]; (ii) [2 þ 2] addition
to acetylide groups to give cyclobutene–metal complexes
[3]; (iii) addition of dicyanomethylene fragments, derived
from cleavage of the double bond of tcne, to an acetylide
group [4]. In all cases except for (i), tcne is reactive to
strongly activated unsaturated groups on the ligands.
Pentamethylcyclopentadienyl rhodium(III) and irid-
ium(III) complexes with the P,O chelating coordination
derived from demethylation of tertiary aromatic phos-
phine ligands bearing the methoxy groups at the ortho-
* Corresponding author. Present address: The Institute of Scientific
and Industrial Research, Osaka University, 8-1 Mihogaoka, Ibaraki,
Osaka 567-0047, Japan. Tel.: +81-6-6879-8456; fax: +81-6-6879-8459.
E-mail addresses: yamamo24@sanken.osaka-u.ac.jp (Y. Yamam-
oto), i45100a@nucc.cc.nagoya-u.ac.jp (K. Tatsumi).
1
Fax: +81-52-789-2943.
0020-1693/$ - see front matter Ó 2004 Elsevier B.V. All rights reserved.
doi:10.1016/j.ica.2004.04.014

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Y. Yamamoto et al. / Inorganica Chimica Acta 357 (2004) 2833–2840
Scheme 1. Reactions of [Cp*MCl{PRPh(2-O-6-MeOC6H3)}] (M ¼ Rh, Ir; R ¼ Ph, 2,6-(MeO)2C6H3) with tcne or Li[F4-tcnq].
of tcne into a C–H bond and a subsequent a,b elimi-
nation from the C(CN)2–CH(CN)2 group to give com-
plexes bearing the 1-cyano-2,20-dicyanoethylene moiety.
In these reactions, we could isolate cyanometal com-
plexes by capture of an eliminated cyano group. Inser-
tion of tcne and subsequent dehydrocyanation have
been noted in the furanyl and thienyl platinum com-
plexes, however a fate of cyano group has not been
described [9]. Recently, Bruce et al. [10] have reported an
unusual formation of cyanoruthenium complex,
Cp*Ru(PPh3)[C(CH@CHPh)@CPhC{CPh@C(CN)2}-
C(CN)2}C(CN)(g2-CN)] (Cp* ¼ C5Me5), from tcne and
an allylic complex, Cp*Ru(PPh3)[g3-CHPhCHC@CPh-
(CCPh)].
2. Results and discussion
2.1. Reactions
When 1a was treated with an equivalence of tcne in
the presence of KPF6, 2a and 3a were isolated in 59.3%
and 4.1% yields, respectively (Scheme 2). Orange brown
complex (2a) has the structure that tcne inserted into the
C–H bond adjacent to the Rh–O bond by comparison
with the spectroscopic data of the known complex [7].
The IR spectrum of 3a showed m(CBN) bands at 2224
and 2152 cmꢀ1 together with a PF6 anion at 841 cmꢀ1
The molecular peak of m=z 1318 corresponded to the
value of [{Cp*Rh(MDMPP-P,O)(tcne)}2]-[HCN + H]
.
Scheme 2. Reactions of 1 with tcne in the presence of KPF6; the PF6 anion was omitted for clarity.

Y. Yamamoto et al. / Inorganica Chimica Acta 357 (2004) 2833–2840
2835
(MDMPP-P,O ¼ PPh2(2-O-6-MeOC6H3)). In the 1H
NMR spectrum, the Cp* protons appeared as two sets
(3a1: d 1.03 and 1.08, and 3a2: d 1.21 and 1.28) with two
kinds of resonances consisting of a 1:1 intensity ratio,
suggesting the presence of isomers. The isomer ratio of
3a1 and 3a2 is 1:5. The detailed structure was confirmed
by X-ray analysis of 3a2 (Fig. 1). The molecule has a
structure that two [Cp*RhPPh2{2-O-3-(C(CN)@C-
(CN)2)-6-(MeO)C6H2}] moieties were connected by a
CBN ligand, in which each of C and N atoms has an
occupancy of 0.5. Since the molecule has a crystallo-
graphically imposed inversion center in the middle of the
C(N)–N(C) bond, the complex has an anti-form to the
C–N triple bond. Complex (3a2) has two chiral centers
at the Rh atoms and the priority order of the ligands at
the Rh center is Cp* > P > O > C(N). Fig. 1 shows the
anti-structure with an RRhSRhꢁ/SRhRRhꢁ pair. Thus,
complex (3a1) is assumed to be an anti-structure with an
RRh
showed to prefer the anti-structure (3a1) with an
R
Rhꢁ/SRhSRhꢁ pair. The PM3 model calculation
R
R
RhRRhꢁ/SRhSRhꢁ to the anti-structure (3a2) with an
RhSRhꢁ/SRhRRhꢁ pair. Less stable complex (3a2), how-
ever, was preferably formed, probably being a result of
steric requirements.
When a similar reaction was performed for the irid-
ium analog 1b, complexes (2b, 3b and 4b) were isolated
in 62.2%, 3.8% and 5.5% yields, respectively. The IR
spectrum of 4b showed the presence of a C–N triple
bond and a PF6 anion. X-ray analysis of 4b was carried
out. Only a cationic molecular structure was found and
an anionic part (PF6 anion) could not be clearly
detected, because of poor single crystals. The cationic
part was solved as a structure in which [Cp*IrPPh2
{2-O-3-(C(CN)@C(CN)2)-6-(MeO)C6H2}] and [Cp*Ir-
(MDMPP-P,O)] moieties were connected by a CBN
ligand. Since the molecular peak of m=z 1396
Fig. 1. Molecular structure of 3a: (a) one molecular structure and (b) two independent molecular structures. The PF6 anions were omitted for clarity.

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Y. Yamamoto et al. / Inorganica Chimica Acta 357 (2004) 2833–2840
corresponded to the value of the cationic molecule, the
cationic molecular structure was assumed to be true.
Thus, 4b is an anti-form with an RIrSIrꢁ/SIrRIrꢁ pair.
In the reaction of 1b with tcne in a 2:1 molar ratio, 3b,
4b and 5b were isolated. The IR spectrum of 5b showed
the presence of the C–N triple bond at 2158 cmꢀ1 and
the PF6 anion at 841 cmꢀ1. In the FAB mass spec-
trometry, the value of m=z 1296 accorded with the value
of [{Cp*Ir(MDMPP-P,O)}2(CN)] (1297.5). The 1H
NMR spectrum showed the presence of two diastereo-
mers (5b1 and 5b2) with a 1:4 molar ratio; the Cp*
protons appeared as singlets at d 1.02 and 1.11 for 5b1
and at d 0.91 and 0.98 for 5b2, respectively. Based on the
structures of 3a and 4b, 5b2 was assumed to be the anti-
structure with an RIrSIrꢁ/SIrRIrꢁ pair and the diastereo-
mer 5b1 was the anti-form with an RIrRIrꢁ/SIrSIrꢁ pair.
Complex (2) reacted readily with KPF6 to eliminate
HCN, generating 3 in relatively high yields (Scheme 3).
Elimination of HCN from the HC(CN)2–C(CN)2–L
(L ¼ organic group bearing a metal) moiety on treat-
ment with alumina has been noted in platinum com-
plexes [9]. A similar reaction was carried out in the
presence of AgOTf instead of KPF6, generating an OTf
anion complex. Reaction of 2 with xylyl isocyanide
(XylNC) in the presence of AgOTf afforded 6 formu-
lated as [Cp*MPPh2{2-O-3-(C(CN)CH(CN)2)-6-MeO-
C6H2}(XylNC)](OTf) (6a: M ¼ Rh; 6b: M ¼ Ir)
(Scheme 3).
Scheme 3. Reactions of 2 with KPF6 or AgOTf in the absence and presence of xylyl isocyanide; the PF6 or OTf anion was omitted for clarity.
Scheme 4. A possible route for the reactions of 1 with tcne in the presence of KPF6.

Y. Yamamoto et al. / Inorganica Chimica Acta 357 (2004) 2833–2840
2837
Table 1
ꢀ
Selected bond lengths (A) and angles (°) for [{Cp*RhPPh2{2-O-3-(C(CN)@C(CN)2)-6-MeO-C6H2}}2(CN)](PF6) 3a2
Bond lengths
Rh(1)–P(1)
2.309(3)
1.10(2)
1.13(2)
2.103(8)
1.33(2)
1.07(2)
Rh(1)–O(1)
C(9)–C(10)
N(3)–C(13)
Rh(2)–N(8)
N(4)–C(46)
2.106(7)
1.37(1)
1.13(2)
2.059(9)
1.15(2)
Rh(1)–C(1) (N7)
N(1)–C(11)
Rh(2)–P(2)
2.057(9)
1.12(2)
2.317(3)
1.13(2)
1.13(2)
C(1)–C(1*) (N7)
N(2)–C(12)
Rh(2)–O(3)
C(44)–C(45)
N(6)–C(48)
N8–N8*(C)
N(5)–C(47)
Bond angles
P(1)–Rh(1)–O(1)
Rh(1)–P(1)–C(3)
Rh(1)–C(N)–N(C)
C(10)–C(9)–C(11)
C(12)–C(10)–C(13)
N(3)–C(13)–C(10)
O(3)–Rh(2)–N(C)
O(3)–C(37)–C(38)
C(42)–C(44)–C(46)
C(44)–C(45)–C(48)
N(5)–C(47)–C(45)
82.8(2)
96.7(1)
174(1)
116(1)
116(1)
178(1)
84.3(4)
121(1)
113(1)
120(1)
175(1)
P(1)–Rh(1)–N(C)
P(1)–C(3)–C(2)
86.6(2)
113.6(7)
124(1)
119(1)
170(1)
82.1(2)
99.1(4)
176(1)
119(1)
115(1)
174(1)
O(1)–Rh(1)–N(C)
O(1)–C(2)–C(3)
84.9(3)
124.2(9)
118.9(9)
124(1)
C(7)–C(9)–C(10)
C(9)–C(10)–C(12)
N(1)–C(11)–C(9)
P(2)–Rh(2)–O(3)
Rh(2)–P(2)–C(38)
Rh(2)–C(N)–N(C)
C(45)–C(44)–C(46)
C(47)–C(45)–C(48)
N(6)–C(48)–C(45)
C(7)–C(9)–C(11)
C(9)–C(10)–C(13)
N(2)–C(12)–C(10)
P(2)–Rh(2)–C(N)
P(2)–C(38)–C(37)
C(42)–C(44)–C(45)
C(44)–C(45)–C(47)
N(4)–C(46)–C(44)
178(1)
92.4(3)
113.6(8)
127(1)
123(1)
173(1)
A possible route was assumed from the reaction
products (Scheme 4). The UV–Vis spectrum of a mix-
ture of 1 with KPF6 is similar to that of 1, suggesting no
extraction of a Cl anion by KPF6. Thus, 2 was initially
generated by insertion of tcne into the C–H bond, ac-
companied by the formation of an intermediate A. Since
in the PM3 model calculation the electron density at the
5-position of the aromatic group in the metallacycle is
(119°), C9–C10–C13 (124°) for the molecule 1, C44–
C45–C47 (123°), C44–C45–C48 (120°) and C47–C45–
C48 (115°) for the molecule 2. The C9–C10 and
ꢀ
C44–C45 bond lengths are 1.37 and 1.33 A, respectively,
being in usual double bonding values. The C(CN)@
C(CN)2 moieties deviate somewhat from their planes as
shown in the torsion angles, for example, C11–C9–C10–
C12 ¼ 174(1)°, C11–C9–C10–C13 ¼ )10(1)°, C46–C44–
C45–C47 ¼ 1(2)° and C46–C44–C45–C48 ¼ )167(1)°. In
the furanyl complex the olefinic part (C(CN)@C(CN)2)
is nearly coplanar with the furan ring [9], whereas in 3a,
the dihedral angles between the aromatic ring and the
C(CN)@C(CN)2 plane are ca. 40°, relieving steric re-
pulsion between two moieties. The average Rh–P bond
2
greater than that at the 3-position, the substitution
reaction is expected to occur preferably at the 5-posi-
tion. It is assumed to be responsible for steric require-
ment of the methoxy group that the reaction occurred at
the 3-position.
The reaction of A with 1 and KPF6 generated 4, and
the reaction with 2 and KPF6 led to the formation of 3.
The CN anion eliminated in this process reacted with 1
to afford an intermediate B, followed by the formation
of 5 from the reaction of B with 1 and KPF6. In these
reactions, intermediates A and B could not be isolated.
ꢀ
ꢀ
length of 2.313 A and Rh–O bond length of 2.105 A are
not significantly different from those found in the related
complexes bearing P,O-coordination [11]. The average
ꢀ
Rh–C(N) bond length of 2.058(9) A is in usual M–C(N)
ꢀ
bond lengths, compared with that (2.077(8) A) found
in [Cp*Rh{P(2,6-(MeO)2C6H3){2-O-3-(1,4-{C(CN)2}2-
C6F4)-6-MeOC6H2}}]2 [8]. The average P–Rh–O bite
angle of 82.5° is similar to those found in rhodium,
iridium and ruthenium bearing this type of ligands
[5,7,11–13]. The average Rh–C(N)–N(C) angle of 175° is
linear and the average C(N)–N(C) length is in the value
of the typical triple bond lengths.
2.2. Crystal structure of 3a
A
perspective drawing with atomic numbering
schemes is given in Fig. 1 and selected bond lengths and
angles are listed in Table 1. Complex (3a) consists of two
independent molecules and each of them has two chiral
centers (two Rh atoms). Fig. 1 shows that the molecule
is an RRhSRhꢁ/SRhRRhꢁ pair. The adoption of the anti-
form is responsible for steric demand of the bulky P,O-
chelating ligand. The presence of the C(CN)@C(CN)2
groups was confirmed by the C10 (or C*10) (molecule 1)
and C45 (or C*45) (molecule 2) atoms with the sp2
carbon atoms; C12–C10–C13 (116°), C9–C10–C12
3. Experimental
3.1. General considerations
All reactions were carried out under a nitrogen atmo-
sphere. Dichloromethane was distilled from CaH2
and diethyl ether was distilled from LiAlH4. Com-
plexes Cp*MCl(MDMPP-P,O) (M ¼ Rh [11], Ir [12] and
2
The charges on the carbon atoms of the 3- and 5-positions are
)0.230 and )0.285, respectively, in the PM3 calculation of 1a.

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Y. Yamamoto et al. / Inorganica Chimica Acta 357 (2004) 2833–2840
[Cp*MCl{PPh2(2-O-3-(C(CN)CH(CN)2)-6-(MeO)-
C6H2)}] (M ¼ Rh, Ir) [7] were prepared according to the
literature. The infrared and electronic absorption spectra
were measured on FT/IR-5300 and U-best 30 instru-
ments, respectively. The 1H NMR spectra were measured
on a JEOL EPC400 instrument at 400 MHz.
(M ¼ cationic molecule).UV–Vis (CH2Cl2): kmax 520,
365, 236 nm. IR(nujol): 2197, 2145 (NBC), 842 (PF6)
cmꢀ1. Anal. Calc. for C64H61F6Ir2N4O4 P3: C, 49.86; H,
3.99; N, 3.63. Found: C, 50.39; H, 3.97; N, 3.46%.
Spectroscopic data of 3b are shown in Section 3.5.
In a 1:0.5 ratio, similarly to the preparation of 3.2, 3b
(3.1 mg, 3.6%), 4b (5.3 mg, 6.6%) and 5b (23.0 mg,
30.7%) were obtained from 1b (70.8 mg, 0.104 mmol),
tcne (7.9 mg, 0.052 mmol) and KPF6 (97.0 mg, 0.52
mmol). Complex (5b) was isolated by fractional recrys-
tallization from CH2Cl2 and hexane. The population
between 5b1 and 5b2 is 1:4. 5b: FAB mass: m=z 1296
([M ) 1]þ) (M ¼ cationic molecule). UV–Vis (CH2Cl2):
kmax 523, ca. 300 nm. IR(nujol): 2158, 2145 (NBC), 841
3.2. Reaction of Cp*RhCl(MDMPP-P,O) (1a) with
TCNE in the presence of KPF6
A mixture of 1a (113.4 mg, 0.195 mmol) and KPF6
(107.9 mg, 0.585 mmol) was stirred in CH2Cl2 (10 ml)
and acetone (10 ml) for 0.5 h at room temperature.
TCNE (25.7 mg, 0.195 mmol) was added to the reaction
mixture and stirred for 48 h. The solvent was removed
under reduced pressure and the residue was extracted
with CH2Cl2. The CH2Cl2 solution was dried and the
residue was washed with diethyl ether. Recrystallization
of the residue from CH2Cl2 and diethyl ether gave the
reddish violet crystals of 3a (5.5 mg, 4.1%) and orange-
brown crystals of the known complex (2a) (77.7 mg,
59.3%). The population between 3a1 and 3b1 is 1:5.
Spectroscopic data are shown in Section 3.3.
1
2
(PF6) cmꢀ1. H NMR (CDCl3): 0.91 (d, JPH ¼ 2:0 Hz,
2
Cp*, 15H)ꢁ2, 0.98 (d, JPH ¼ 2:0 Hz, Cp*, 15H)ꢁ2, 1.02
2
2
(d, JPH ¼ 2:0 Hz, Cp*, 15H)ꢁ1, 1.11 (d, JPH ¼ 2:0 Hz,
Cp*, 15H)ꢁ1, 3.46 (s, MeO, 3H)ꢁ1, 3.47 (s, MeO, 3H)ꢁ1,
3.58 (s, MeO, 6H)ꢁ2, 6.6–8.2 (m, Ph, 24H)ꢁ1 þ 2. Anal.
Calc. for C59H64F6Ir2NO4P3: C, 49.13; H, 4.47; N, 0.97.
Found: C, 48.78; H, 4.29; N, 1.17%.
3.5. Reaction of 2b with KPF6
Similarly to the preparation of 3.3, complex (3b) (15.7
mg, 52.8%) was obtained from the reaction of 2b (23.3 mg,
0.036 mmol) and KPF6 (20.0 mg, 0.11 mmol). FAB mass:
m=z 1498 ([M]þ) (M ¼ cationic molecule). UV–Vis
(CH2Cl2): kmax 519, 374, 328 nm. IR(nujol): 2216, 2148
3.3. Reaction of 2a with KPF6
A mixture of 2a (133.1 mg, 0.188 mmol) and KPF6
(172.8 mg, 0.936 mmol) was stirred in CH2Cl2 (10 mL)
and acetone (10 mL) at room temperature. After 24 h,
the solvent was removed under reduced pressure and the
residue was extracted with CH2Cl2. Removal of the
solvent and recrystallization of the residue from CH2Cl2
and hexane gave reddish violet complex of 3a (42.0 mg,
83.9%). FAB mass: m=z 1318 ([M]þ) (M ¼ cationic
molecule). UV–Vis (CH2Cl2): kmax 521, 367, 328 nm.
IR(nujol): 2224, 2152 (CBN), 841 (PF6) cmꢀ1. 1H NMR
(CDCl3): d 1.03 (d, JPH ¼ 3:7 Hz, Cp*, 15H)a1, 1.08 (d,
JPH ¼ 3:6 Hz, Cp*, 15H)a1, 1.21 (d, 2JPH ¼ 3:3 Hz, Cp*,
1
(NBC), 839 (PF6) cmꢀ1. H NMR (CDCl3): d 1.57 (d,
2JPH ¼ 1:8 Hz, Cp*, 30H)ꢁ1, 1.70 (d, 2JPH ¼ 1:8 Hz, Cp*,
15H)ꢁ2, 3.50 (s, Me, 3H)ꢁ1, 3.53 (s, Me, 3H)ꢁ2, 6.1-7.9 (m,
Ph, 24H)ꢁ1 þ 2. Anal. Calc. for C69H60F6Ir2N7O4 P3: C,
50.45;H, 3.68;N, 5.97. Found:C, 50.39;H, 3.97;N, 6.46%.
3.6. Reaction of 2a with xylyl isocyanide in the presence
of AgOTf
A mixture of 2a (70.1 mg, 0.099 mmol) and AgOTf
(52.7 mg, 0.205 mmol) was stirred in CH2Cl2 (10 mL)
and acetone (10 mL) at room temperature. After 1 h,
xylyl isocyanide (19.1 mg, 0.152 mmol) was added to the
reaction mixture. After the mixture was stirred for 24 h,
the solvent was removed under reduced pressure and the
residue was extracted with CH2Cl2. The solvent was
removed and the residue was washed with diethyl ether.
Recrystallization of the residue from CH2Cl2 and di-
ethyl ether gave an orange complex of 6a (54.7 mg,
58.1%). FAB mass: m=z 804 ([M]þ) (M ¼ cationic mol-
ecule). UV–Vis (CH2Cl2): kmax 350, 319 nm. IR(nujol):
2
15H)a2, 1.28 (d, JPH ¼ 3:3 Hz, Cp*, 15H)a2, 3.67 (s,
Me)a1 þ a2, 3.69 (s, Me)a1 þ a2, 5.27 (s, CH2Cl2), 9.95–8.12
(m, Ph, 24H). Anal. Calc. for C69H60F6N7O4P3Rh 2 ꢂ
2CH2Cl2: C, 52.19; H, 3.95; N, 6.00. Found: C, 51.94;
H, 4.10; N, 6.04%.
Analogously, the complex bearing an OTf anion was
obtained from 2a and AgOTf, identifying in comparison
with spectroscopic data of 3a.
3.4. Reaction of Cp*IrCl(MDMPP-P,O) (1b) with
TCNE in the presence of KPF6
1
2179 (NBC, CBN), 1261, 1155, 1030 (OTf) cmꢀ1. H
2
In a 1:1 ratio, similarly to the preparation of 3.2, 2b
(76.6 mg, 62.2%), 3b (5.6 mg, 3.8%) and 4b (8.2 mg, 5.5
%) were obtained from a mixture of 1b (130.7 mg, 0.195
mmol), tcne (25.7 mg, 0.195 mmol) and KPF6 (179.5
mg, 0.975 mmol). 4b: FAB mass: m=z 1396 ([M ) 1]þ)
NMR (CDCl3): d 1.87 (d, JPH ¼ 3:0 Hz, Cp*, 15H),
1.95 (s, o-Me 6H), 3.56 (s, MeO, 3H), 5.28 (s, CH2Cl2),
6.46 (s, CH@, 1H), 7.24–7.80 (m, Ph, 15H). Anal. Calc.
for C45H40F3N5O5PRhS ꢂ 0.25CH2Cl2: C, 55.74; H,
4.19; N, 7.18. Found: C, 55.59; H, 4.26; N, 7.13%.

Y. Yamamoto et al. / Inorganica Chimica Acta 357 (2004) 2833–2840
2839
3.7. Reaction of 2b with xylyl isocyanide in the presence
of AgOTf
Lorentz and polarization effects. Atomic scattering fac-
tors were taken from the usual tabulation of Cromer
and Waber [14]. Anomalous dispersion effects were in-
cluded in Fcalc [15]; the values of Df 0 and Df 00 were those
of Creagh and McAuley [16]. All calculations were
performed using the TEXSAN crystallographic software
package [17].
Similarly to the preparation of 6a, orange complex
(6b) (14.0 mg, 17.3%) was obtained from the reaction of
2bꢁ (50.0 mg, 0.078 mmol), xylyl isocyanide (15.8 mg,
0.116 mmol) and AgOTf (39.9 mg, 0.155 mmol). FAB
mass: m=z 894 ([M]þ) (M ¼ cationic molecule). UV–Vis
(CH2Cl2): kmax 312 nm. IR(nujol): 2179 (NBC, CBN),
1261, 1155, 1032 (OTf) cmꢀ1. 1H NMR (CDCl3): d 1.95
(d, 2JPH ¼ 2:5 Hz, Cp*, 15H), 2.10 (s, o-Me 6H), 3.60 (s,
MeO, 3H), 6.40 (s, CH@, 1H), 7.1–8.0 (m, Ph, 15H).
Anal. Calc. for C45H40F3IrN5O5PS: C, 51.82; H, 3.87;
N, 6.71. Found: C, 51.54; H, 3.93; N, 6.48%.
3.9. Determination of the structure
Complex was solved by Patterson methods (DIR-
DIF94 PATTY). The non-hydrogen atoms were refined
anisotropically using full-matrix least-squares based on
F values. All hydrogen atoms were calculated at the
ꢀ
ideal positions with the C–H distance of 0.97 A. The
3.8. Data collection
complex consists of two independent molecules. Each
crystal unit has a crystallographically imposed inver-
sion center in the middle of the C(N)–N(C) bond. The
C(N) and N(C) atoms were refined as the occupancy of
0.5. The CN group for the molecule 1 was calculated
as the C atoms and that for the molecule 2 as the N
atoms.
Complex (3a) was recrystallized from CH2Cl2/hex-
ane. The measurement was made on a Rigaku/MSC
Mercury CCD diffractometer, using Mo Ka radiation at
20 °C. Four preliminary data frames were measured at
0.5° increments of x, in order to assess the crystal
quality, and preliminary unit cell parameters were cal-
culated. The cell parameters were refined using all re-
flections measured in the range 2:8° < 2h < 55°. The
intensity images were measured at 0.5° intervals of x for
a duration of 20 s. The frame data were integrated using
4. Conclusion
Pentamethylcyclopentadienylrhodium(III) and -irid-
ium(III) complexes bearing a P,O-coordination reacted
readily with electron-withdrawing olefins, generating
various kinds of complexes under different reaction
conditions. For example, the reaction of 1 with neutral
tcne or tcnq led to insertion of olefin into the C–H bond
adjacent to the M–O bond, affording 2 [5]. Reactions
with Li[F4-tcnq] gave binuclear macrocyclic complexes
(Scheme 1) [8].
In this paper, the reactions with tcne in the presence
of KPF6 led to cleavage of the C–CN bond, generating
complexes (3–5) bearing CN and C(CN)–C(CN)2 moi-
eties. These reactions were found to proceed via an
initial formation of 2. Reactions described here are ad-
ded to the chemistry of electron withdrawing tcne.
Reactions of 1 with tcne in the presence of KPF6 are
not clean and the formation of various complexes except
isolated complexes should be considered. Thus, we
could not isolate all complexes that would be formed in
these reactions. Reactions of 2 with KPF6 generated 3 in
relatively high yields, but we could not confirm the fate
of HCN.
a
D*TREK program package and the data sets were
corrected for absorption using a REQAB program.
The crystal parameters along with data collections
are summarized in Table 2. Intensities were collected for
Table 2
Crystal data for [{Cp*RhPPh2{2-O-3-(C(CN) ¼ C(CN)2)-6-(MeO)-
a
C6H2}}2(CN)](PF6) 3a2
Formula
C90H90Cl2F6N4 O4P2Rh2
1744.38
triclinic
Formula weight
Crystal system
Space group
ꢁ
P1 (No. 2)
Lattice parameters
ꢀ
a (A)
ꢀ
13.616(4)
14.616(6)
19.845(9)
83.00(2)
76.69(2)
64.53(2)
3468(2)
2
b (A)
ꢀ
c (A)
a (°)
b (°)
c (°)
3
ꢀ
V (A )
Z
Dcalc (g/cm3)
1.670
6.77
l(Mo KaÞ (cmꢀ1
)
2hmax
55.0
15 154
No. measured (uniqueness)
No. observed
No. variables
5. Supplementary materials
8578 (I > 3:0rðIÞ)
857
R; Rwb
Goodness-of-fit
0.107; 0.146
2.08
Table listing detailed crystallographic data, atomic
positional parameters and bond lengths and angles an
be obtained from the authors upon request. CCDC:
224536 for 3a.
a Measured by Rigaku/MSC Mercury CCD at 20°.
P
P
P
P
2
1=2
b R ¼ jFoj ꢀ jFcj= jFoj and Rw ¼ ½ wðjFoj ꢀ jFcjÞ = wFo2ꢃ
.

2840
Y. Yamamoto et al. / Inorganica Chimica Acta 357 (2004) 2833–2840
(d) Y. Yamamoto, K. Sugawara, M. Kakeya, Inorg. Chim. Acta
340 (2002) 21.
Acknowledgements
[6] Y. Yamamoto, J. Seta, H. Murooka, X.-H. Han, Inorg. Chem.
Commun. 6 (2003) 202.
The work was partially supported by a Gant-in Aid
for Scientific Research, from the ministry of Education,
Science, Culture and Sports, Japan (12640545).
[7] (a) Y. Yamamoto, X.-H. Han, S. Nishimura, K. Sugawara, N.
Nezu, T. Tanase, Organometallics 20 (2001) 266;
(b) Y. Yamamoto, X.-H. Han, K. Sugawara, S. Nishimura,
Angew. Chem., Int. Ed. 38 (1999) 1242.
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