Unsymmetrically substituted bis(carbene)platinum(II) complexes

Article abstract of DOI:10.1016/S0022-328X(98)00937-1

Consecutive nucleophillic attack by an alcohol and then an amine to a trans-diiodo[bis(isocyanide)]platinum(II) complex 1 gives an unsymmetrically substituted neutral bis(carbene)platinum complex, trans-diiodo{[diaminocarbene][(alkoxy)(amino)carbene]}-platinum(II) 4, some of which, bearing a long alkyl substituent on the carbene ligand, exhibit a liquid crystalline property.

Full text of DOI:10.1016/S0022-328X(98)00937-1

Journal of Organometallic Chemistry 574 (1999) 163–170
Unsymmetrically substituted bis(carbene)platinum(II) complexesꢀ
Shi-Wei Zhang, Fumie Motoori, Shigetoshi Takahashi *
The Institute of Scientific and Industrial Research, Osaka Uni6ersity, Mihogaoka, Ibaraki, Osaka 567-0047, Japan
Received 4 July 1998; received in revised form 3 August 1998
Abstract
Consecutive nucleophillic attack by an alcohol and then an amine to a trans-diiodo[bis(isocyanide)]platinum(II) complex 1 gives
an unsymmetrically substituted neutral bis(carbene)platinum complex, trans-diiodo{[diaminocarbene][(alkoxy)(amino)carbene]}
platinum(II) 4, some of which, bearing a long alkyl substituent on the carbene ligand, exhibit a liquid crystalline property. © 1999
Elsevier Science S.A. All rights reserved.
Keywords: Platinum; Hetero-bis(carbene); Mesomorphic property
1. Introduction
showed a reactivity for intramolecular metalation, but
they did not exhibit mesomorphic properties because of
their high melting temperature (decomposition at about
180°C), although chloro(carbene)gold complexes form
stable liquid crystals around 120°C.
The preparation of Fischer-type carbene complexes
involves the effective addition of nucleophiles to transi-
tion metal acetylide and isocyanide complexes, in which
nucleophiles HQ attack the positively charged h-carbon
atom of M–CꢀCR and M–CꢀNR to give carbene
complexes. The preparation of the type MꢁCQ–CHR
(M=Pt, Pd and Ni) carbene complexes from M–
CꢀCR complexes has extensively been studied by Clark
[1] and Okawara [2]. On the other hand, carbene com-
plexes of the type MꢁCQ–NHR with a variety of
transition metals were prepared from M–CꢀNR com-
plexes [3,4]. We also applied this method to the synthe-
sis of liquid-crystalline gold(I)-carbene complexes from
chloro(isocyanide)gold(I) [5,6]. Furthermore, we have
prepared first neutral trans-bis(diaminocarbene)plati-
num complexes by the nucleophilic addition of amines
to both of the CꢀN bonds in bis(isocyanide)platinum
complexes (Eq. (1)) [7]. These complexes have two
symmetrically substituted diaminocarbene ligands and
(1)
We have now found that treatment of trans-diiodo[-
bis(isocyanide)]platinum(II) complex 1 with alcohol and
then amine nucleophiles results in formation of a new
type of platinum carbene complexes, trans-diiodo
{[diaminocarbene][(alkoxy)(amino)]carbene]}plati-
num(II) 4 (Eq. (2)). This is the first example of unsym-
metrically substituted bis(carbene)metal complexes al-
though some symmetrical bis(carbene)metal complexes
are known [8]. We also found that comlexes 4 showed
a mesomorphic property when they have long alkyl
substituents on the carbene ligands.
ꢀ Dedicated to the memory of the late Professor Rokuro Okawara.
* Corresponding author. Fax: +81-6-879-8459.
0022-328X/99/$ - see front matter © 1999 Elsevier Science S.A. All rights reserved.
PII: S0022-328X(98)00937-1

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S.-W. Zhang et al. / Journal of Organometallic Chemistry 574 (1999) 163–170
Scheme 1.
(2)
2. Results and discussion
various kinds of solvents. When 2 was heated in
propanol under reflux, a mixture of products was ob-
tained but we could not isolate definite products. Then,
we adopted route B and found two kinds of methods
for the synthesis of bis{[diaminocarbene][(alkoxy)
(amino)carbene]}platinum(II) 4.
Two possible synthetic routes to unsymmetrically
substituted bis(carbene)platinum, trans-diiodo{[diam-
inocarbene][(alkoxy)(amino)carbene]}platinum(II)
4,
can be considered (Scheme 1). One is route A, in which
the nucleophilic attack of an amine to one of the CꢀN
bonds of 1 leads to mono-[(diamino)carbene]platinum
complex 2, and then the addition of an alcohol to the
other CꢀN bond of 2 would result in the formation of
4. In route B, the addition of an alcohol to 1 may form
monocarbene 3 and then the addition of an amine to 3
gives 4. At first according to route A we reacted
complex 1 (Y=C8H17 or C4H7) with propylamine (one
equivalent) in benzene at room temperature and iso-
lated monocarbenes 2 in 90% yields. However, no
reaction occurred when propanol was added to the
solution of monocarbene 2 at room temperature in
2.1. Synthesis of diiodo{[isocyanide][(alkoxy)(amino)
carbene]}-platinum(II) complexes
Propanol did not react with trans-diiodo[bis(4-
octylphenyl isocyanide)]platinum(II) 1e in solvents such
as benzene and dichloromethane even if the reaction
was carried out at the reflux temperature. However,
when a solution of complex 1e in propanol was heated
for 24 h at reflux temperature (89°C), a mixture of
complexes 3e and 5e were obtained in a ratio of 4:1
(Eq. (3)).
(3)

S.-W. Zhang et al. / Journal of Organometallic Chemistry 574 (1999) 163–170
165
Table 1
but we could not find a suitable method to isolate 3
from the product mixtures. Although most of com-
plexes 3 have not been isolated from the mixture of 3
and 5, complexes 3b–e were successfully separated by
means of recrystallization from hexane–dichlorome-
thane (entries 4, 7, 10 and 13). On the other hand, we
found that the reaction of isolated complex 3e with
propanol also gave a mixture of 3e and 5e with a ratio
of 4:1 (Eq. (4)), suggesting that there may be an equi-
librium between 3 and 5 in the reaction of 3 with
propanol in spite of the presence of large excess of
propanol.
Reaction of complex 1e with propanola
Entry Reaction time
(h)
Conversion of
1e (%)
Ratio of products
3e:5eb
1
2
3
4
5
6
0.5
3
11
55
1:1
2:1
4:1
4:1
4:1
4:1
16
84
20
24
48
92
100
100
a Complex 1e (0.1 mmol), propanol (5 ml), reflux.
b Determined by HPLC and 1H-NMR analysis.
Complex 3e was identified to be a mono(carbene) com-
plex, diiodo{[isocyanide][(alkoxy)(amino)carbene]}-
(4)
platinum(II), while complex 5e is a bis(carbene) com-
plex, diiodo-bis[(alkoxy)(amino)carbene]platinum(II).
As shown in Table 1, the production of 3e was always
accompanied with the formation of 5e although we
tried to find the reaction conditions for the selective
synthesis of mono(carbnene) 3e. Although the conver-
sion of substrate 1e reached 100% after 24 h, the
reaction gave a mixture of 3e and 5e with a ratio of 4:1,
and the ratio of 3e/5e was held constant at 4:1 even
after the reaction for 48 h. All the reactions of complex
1 with several kinds of alcohols gave a mixture of
complexes 3 and 5 (Table 2). For example, complex 1a
reacted with propanol, ethanol and methanol to give
the corresponding products 3 and 5 (entries 1, 2 and 3),
2.2. Synthesis of trans-diiodo{[diaminocarbene][(alkoxy)
(amino)carbene]}platinum 4 by the reaction of
monocarbene 3 with propylamine
To synthesize unsymmetrical bis(carbene) complexes,
we examined the reaction of mono(carbene) complex 3
with an amine and successfully obtained [diaminocar-
bene][(alkoxy)(amino)carbene] complexes 4 in an excel-
lent yield. Thus, isolated mono(carbene) complex 3b
was reacted with propylamine in benzene at room
temperature for 24 h to give complex 4b, after recrystal-
lization from hexane–dichloromethane, as pale yellow
powders in 97% yield (Eq. (5)).
Table 2
Reactions of complex 1 with alcoholsa
Entry
Complex 1
Y
Alcohol
R1
Conversion of 1
(%)
Ratio of products 3 and 5
(3:5)b
Isolated yield of 3
(%)
c
1
2
3
a
b
c
d
e
Me
Pr
Et
Me
100
100
65
3:1
5:1
2:1
–
–
–
c
c
4
5
6
OMe
Bu
Pr
Et
Me
100
100
67
8:3
2:1
1:1
33
c
–
–
c
7
8
9
Pr
Et
Me
100
100
60
4:1
4:1
8:3
29
c
–
–
c
10
11
12
OHex
Oct
Pr
Et
Me
100
100
63
4:1
4:1
2:1
34
c
–
–
c
13
14
15
Pr
Et
Me
100
100
65
4:1
4:1
4:1
54
c
–
–
c
a Complex 1 (0.1 mmol), alcohol (5 ml), reflux for 24 h.
b Determined by HPLC and 1H-NMR analysis.
c Not isolated from the mixture of complexes 3 and 5.

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S.-W. Zhang et al. / Journal of Organometallic Chemistry 574 (1999) 163–170
propanol and propylamine to the NꢀC bonds with the
formation of heterobis(carbene) complex 4. In the IR
spectra of 4, absorptions due to w(N–H) and w(NꢁC)
were found around 3276 and 1548 cm−1, respectively,
with complete disappearance of the absorption due to
w(NꢀC) at about 2186 cm−1 in 3. The structure of 4b
was finally confirmed by an X-ray crystallographic
study (Fig. 1) (see Section 4) as well as the results of
elemental analysis. The molecular structure shows that
4b possesses a trans square-planar configuration having
central metal platinum, which carries two iodo and two
carbene ligands with a typical bond distance of 2.027(1)
˚
A for trans PtꢁC ([3]c, [7,8]). It is a C2 symmetrical
structure irrespective of the two different carbene lig-
ands, diaminocarbene and (alkoxy)(amino)carbene.
This is the first example of neutral heterobis(car-
bene)metal complexes by a simple sequential nucle-
ophilic additions of alcohol and amine to bis(isocyan-
ide)platinum complexes.
2.3. Direct synthesis of trans-diiodo{[diamino-
carbene][(alkoxy)(amino)carbene]}platinum 4 by the
reaction of complex 1 with alcohol and then amine
Due to the difficulties in separating mono(carbene)
complexes 3 from the mixture of 3 and 5, we tried to
convert 3 to 4 by directly adding amine to the mixture
of 3 and 5. Successfully, a mixture of 4e and 5e was
obtained by the addition of propylamine (two equiva-
lents to 1e) to the mixture of 3e and 5e (3e:5e=4:1)
which was produced by the reaction of 1e with
propanol at reflux temperature (Eq. (6)). Heterobis(car-
bene) complex 4e can be easily separated from the
mixture of 4e and 5e by means of recrystallization from
hexane–dichloromethane. Surprisingly, on adding a
large excess of propylamine (20 equivalents to 1e) to the
mixture of 3e and 5e, heterobis(carbene) complex 4e
was obtained as a single product and no remaining
homobis[(alkoxy)(amino)carbene] complex 5e was de-
Fig. 1. ORTEP drawing of complex 4b (Y=OCH3, R=R%=C3H7).
Selected bond distances (A) and angles (°): Pt(1)–C(1), 2.027(1);
Pt(1)–I(1), 2.627(1); C(1)–O(1), 1.329(7); C(1)–N(1), 1.336(8); C(1)–
N(2), 1.329(6); I(1)–Pt(1)–I(1)*, 180.0; C(1)–Pt(1)–C(1)*, 180.0;
C(1)–Pt(1)–I(1), 89.9(2); C(1)–Pt(1)–I(1)*, 90.1(2); N(1)–C(1)–N(2),
113.3(5); O(1)–C(1)*–N(1)*, 113.3(5).
˚
The similar reaction of 3c, 3d and 3e gave the corre-
sponding heterobis(carbene) complexes 4c, 4d and 4e.
Consequently, both of two isocyanide ligands coordi-
nated to Pt(II) underwent consecutive 1,2-addition of
(5)
(6)

S.-W. Zhang et al. / Journal of Organometallic Chemistry 574 (1999) 163–170
167
tected (Eq. (6)). On the other hand, 5e which was isolated
3. Conclusion
from a mixture of 4e and 5e reacted with propylamine
(20 equivalents to 5e) in benzene to give 4e quantitatively
and no further reaction occurred (Eq. (7)). These exper-
imental facts show that only one alkoxy substituent on
the two carbene ligands was replaced by the amine to
form a diaminocarbene ligand although the reason why
the other does not undergo replacement with amine is not
clear at present.
Two kinds of methods for synthesizing unsymmetri-
cally substituted neutral bis(carbene)platinum complex,
trans - diiodobis{[diaminocarbene][(alkoxy)(amino)car -
bene]}platinum(II) have been developed. One of them is
the consecutive nucleophilic attack by an alcohol and
then an amine to a trans-diiodo[bis(isocyanide)]plati-
(7)
As shown in Table 3, the reactions of trans-diiodo[bi-
s(isocyanide)]platinum 1a–e with propanol and then
propylamine gave the corresponding unsymmetrically
substituted neutral bis(carbene)platinum complexes 4a–
e in good yields (entries 1–5). The reaction of 1e
(Y=Oct) with propanol and then ethylamine gave
diiodo{[(4-octylphenylamino)(ethylamino)carbene][(4-
octylphenylamino)(propoxy)carbene]}platinum(II) 4f in
84% yield.
Similarly, 1g reacted with propanol and then propy-
lamine to give 4g in 62% yield, which has a long
alkoxy-substituented biphenyl group on the carbene
ligands (Eq. (8)). Heterobis(carbene) complex 4g melts
at a lower temperature than the corresponding homo-
bis(carbene) complex and has been firstly demonstrated
to exhibit a mesomorphic property. Now a further effort
is being made to synthesize liquid crystalline heterobis(-
carbene)platinum complexes having long alkyl sub-
stituents on the carbene ligands by the present
methodology.
num(II) complex, which provides a simple and versatile
methodology for the synthesis of heterobis(car-
bene)metal complexes.
4. Experimental section
Melting points were recorded on a Yamato melting
point apparatus MP21 and are not corrected. Elemental
microanalyses were performed by the Material Analysis
Center, ISIR, Osaka University. IR spectra were ob-
tained with a Perkin Elmer 2000 FT-IR system. 1H-NMR
spectra were recorded on a JNM-LA400 FT NMR
system in CDCl3 with tetramethylsilane as an internal
standard.
4.1. Materials
Platinum–isonitrile complexes, trans-diiodo[bis(iso-
cyanide)]platinum(II), were prepared by the known
methods [7]. Solvents such as dichloromethane and
benzene were distilled before used. Amines and alcohols
were used as received from commercial sources.
4.2. General procedure for preparation of
mono(diaminocarbene)platinum complexes 3 by reaction
of bis(isocyanide)platinum(II) complexes 1 with alcohols
A solution of trans-bis(isocyanide)platinum 1 (0.3
mmol) in propanol (15 ml) was stirred for 20 h at reflux
temperature under argon. After the solvent was evapo-
rated, the resultant residue containing 3 and 5 was
purified by a short column. Recrystallization from
CH2Cl2/hexane gave monocarbenes 3.
4.2.1. Diiodo[(4-methoxyphenylamino)
(propoxy)carbene][4-methoxyphenylisocyanide]
platinum(II) (3b)
The general procedure was followed using trans-bis(4-
methoxyphenylisocyanide)platinum (0.215 g, 0.3 mmol)
(1b) and propanol (15 ml). 3b was obtained as pale yellow
(8)

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S.-W. Zhang et al. / Journal of Organometallic Chemistry 574 (1999) 163–170
Table 3
Reactions of complex 1 with propanol and aminesa
Entry
Complex 1
Y
Amine
R2
Isolated yield of 4
(%)
1
2
3
4
5
6
a
b
c
d
e
f
Me
OMe
Bu
Ohex
Oct
Oct
Pr
Pr
Pr
Pr
Pr
Et
86
84
78
79
82
84
a (1) Complex 1 (0.3 mmol), propanol (15 ml), reflux for 24 h. (2) Amine (6.0 mmol) in benzene for 24 h.
crystals (0.077 g, 33% yield). M.p. 75.1–75.6°C; IR(KBr):
4.2.4. Diiodo[(4-octylphenylamino)(propoxy)carbene]
[4-octylphenylisocyanide]platinum(II) (3e)
1
3325 w(N–H), 2193 w(CꢀN), 1540 w(CꢁN) cm−1; H-
NMR (400 MHz, CDCl3): l 8.18 (s, 1H, NHAr), 7.42
(d, 2H, J=9.0 Hz, Ar), 7.23 (d, 2H, J=9.2 Hz, Ar),
6.93–6.87 (m, 4H, Ar%), 4.93 (t, 2H, J=6.7 Hz,
OCH2C2H5), 3.85 (s, 3H, OCH3), 3.82 (s, 3H, OCH3),
1.90–1.80 (m, 2H, OCH2CH2CH3), 0.97 (t, 3H, J=7.3
Hz, OC2H4CH3); Mass (M+) 775.
Yellow powders, 54% yield. M.p. 67.3–68.0°C;
IR(KBr): 3263 w(N–H), 2186 w(CꢀN), 1538 w(CꢁN)
cm−1 1H-NMR (400 MHz, CDCl3): l 8.24 (s, 1H,
;
NHAr), 7.38 (d, 2H, J=8.3 Hz, Ar), 7.26–7.17 (m, 6H,
Ar), 4.95 (t, 2H, J=6.6 Hz, OCH2C2H5), 2.66–2.58 (m,
4H, 2×CH2C7H15), 1.91–1.82 (m, 2H, OCH2CH2CH3),
1.60–1.53 (m, 4H, 2×CH2CH2C6H13), 1.30–1.26 (m,
20H, 2×C2H4C5H10H3), 0.96 (t, 3H, J=7.3 Hz,
OC2H4CH3), 0.88 (m, 6H, 2×C7H14CH3); Mass (M+)
939; Anal. Calc. for C33H50N2O1I2Pt: C, 42.41; H, 5.16;
N, 2.77; I, 26.85. Found: C, 42.18; H, 5.36; N, 2.98; I,
27.10%.
4.2.2. Diiodo[(4-butylphenylamino)(propoxy)carbene]
[4-butylphenylisocyanide]platinum(II) (3c)
Yellow powders, 29% yield. M.p. 70.5–71.2°C;
IR(KBr): 3294 w(N–H), 2194 w(CꢀN), 1540 w(CꢁN)
cm−1 1H-NMR (400 MHz, CDCl3): l 8.28 (s, 1H,
;
NHAr), 7.39 (d, 2H, J=8.5 Hz, Ar), 7.27–7.18 (m, 6H,
Ar and Ar%), 4.96 (t, 2H, J=6.7 Hz, OCH2C2H5),
2.67–2.60 (m, 4H, 2×CH2C3H7), 1.92–1.83 (m, 2H,
OCH2CH2CH3), 1.64–1.56 (m, 4H, 2×CH2CH2C2H5),
1.40–1.31 (m, 4H, 2×C2H4CH2CH3), 1.01 (t, 3H, J=
7.4 Hz, OC2H4CH3), 0.96–0.92 (m, 6H, 2×C3H6CH3);
Mass (M+) 827.
4.3. General procedures for preparation of
[diaminocarbene][(alkoxy)(amino)carbene]platinum
complexes 4
4.3.1. Synthesis of 4 (4b–e) by the reaction of isolated
mono(diaminocarbene)platinum complexes 3 (3b–e)
with propylamine
4.2.3. Diiodo[(4-hexyloxyphenylamino)(propoxy)-
carbene][4-hexyloxyphenylisocyanide]platinum(II) (3d)
Yellow powders, 34% yield. M.p. 71.2–71.5°C; IR(K-
To a solution of 3e (94 mg, 0.1 mmol) in benzene (5
ml) was added propylamine (12 mg, 0.2 mmol). After
stirring for 24 h at room temperature under argon, the
solvent was evaporated and the resultant residue was
recrystallization from CH2Cl2/hexane to give 4e (99 mg,
98% yield) as yellow powders. In analogous manners, 4b,
4c and 4d were obtained in 97, 98 and 97% yield,
respectively.
Br): 3280 w(N–H), 2191 w(CꢀN), 1548 w(CꢁN) cm−1
;
1H-NMR (400 MHz, CDCl3): l 8.18 (s, 1H, NHAr), 7.39
(d, 2H, J=9.0 Hz, Ar), 7.21 (d, 2H, J=8.8 Hz, Ar), 6.90
(d, 2H, J=9.3 Hz, Ar), 6.87 (d, 2H, J=9.0 Hz, Ar), 4.92
(t, 2H, J=6.7 Hz, OCH2C2H5), 3.97 (t, 2H, J=6.6 Hz,
OCH2C5H11), 3.95 (t, 2H, J=6.6 Hz, OCH2C5H11),
1.88–1.74 (m, 4H, 2×OCH2CH2C4H9), 1.48–1.42 (m,
2H, OCH2CH2CH3), 1.36–1.34 (m, 12H, 2×OC2H4
C3H6CH3), 0.97 (t, 3H, J=7.4 Hz, OC2H4CH3), 0.91 (t,
3H, J=6.7 Hz, OC5H10CH3); Mass (M+) 915; Anal.
Calc. for C29H42N2O3I2Pt: C, 38.16; H, 4.64; N, 2.82; I,
27.45. Found: C, 38.04; H, 4.63; N, 3.06; I, 27.72%.
4.3.2. Direct synthesis of 4 by the reaction of complex
1 with alcohol and then amine
A solution of 1a (170 mg, 0.3 mmol) in propanol (15
ml) was stirred for 24 h at reflux temperature (89°C)
under argon. After the solvent was evaporated, the

S.-W. Zhang et al. / Journal of Organometallic Chemistry 574 (1999) 163–170
169
resultant residue was resolved in benzene (10 ml) and
then propylamine (360 mg, 6.0 mmol) was added to
the solution. After stirring for 24 h at room tempera-
ture under argon, the solvent was evaporated and the
resultant residue was recrystallized from CH2Cl2/hex-
ane to give 4a (210 mg, 86% yield) as yellow powders.
In analogous manners, 4b–h were obtained.
weighted agreement factors of: R=0.029, Rw=0.029.
Since 4b is exactly centrosymmetric, only 142 parame-
ters were used to model C11H16N2OIPt. A final differ-
ence-Fourier map possessed some peaks near the
platinum atom with the largest peak, –1.135Dz5
−3
˚
0.57 e A
4.3.5. Diiodo {[(4-buthylphenylamino)(propylamino)-
carbene][(4-buthylphenylamino)(propoxy)carbene]}
platinum(II) 4c
4.3.3. Diiodo{[(4-methylphenylamino)(propylamino)-
carbene][(4-methylphenylamino)(propoxy)
carbene]}platinum(II) 4a
Yellow powders, 78% yield. M.p. 139.4–140.0°C;
1
IR(KBr): 3272 w(N–H), 1563 w(CꢁN) cm−1; H-NMR
Yellow powders, 86% yield. M.p. 188.2–189.0°C;
1
IR(KBr): 3242 w(N–H), 1553 w(CꢁN) cm−1; H-NMR
(400 MHz, CDCl3): l 8.21 (bs, 2H, NHAr), 7.28–7.09
(m, 8H, Ar), 6.11 (bs, 1H, NHC3H7), 5.05 (m, 2H,
OCH2C2H5), 3.82 (m, 2H, NHCH2C2H5), 2.62 (m,
4H, 2×CH2C3H7), 1.89 (m, 2H, OCH2CH2CH3), 1.62
(m, 2H, NHCH2CH2CH3), 1.39–1.30 (m, 8H, 2×
CH2C2H4CH3), 1.11–0.87 (m, 12H, NHC2H4CH3+
(400 MHz, CDCl3): l 8.35 (bs, 1H, NHAr), 8.16 (bs,
1H, NHAr), 7.22–7.10 (m, 4H, Ar), 6.95–6.83 (m,
4H, Ar), 6.93–6.81 (m, 4H, Ar%), 5.94 (sb, 1H,
NHC3H7), 5.07 (m, 2H, OCH2C2H5), 3.81 (m, 2H,
NHCH2C2H5), 2.35 (bs, 6H, 2×CH3), 1.86 (m, 2H,
OCH2CH2CH3), 1.68 (m, 2H, NHCH2CH2CH3), 0.96
(t, 3H, J=7.6 Hz, NHC2H4CH3), 0.89 (t, 3H, J=7.3
Hz, OC2H4CH3); Mass (M+) 803; Anal. Calc. for
C22H31N3O1I2Pt: C, 33.22; H, 3.94; N, 5.29; I, 31.85.
Found: C, 32.93; H, 3.89; N, 5.24; I, 31.63%.
OC2H4CH3+2×C3H6CH3);
Anal.
Calc.
for
C28H42N3O1I2Pt: C, 38.30; H, 4.64; N, 4.47; I, 28.72.
Found: C, 37.93; H, 4.89; N, 4.74; I, 28.63%.
4.3.6. Diiodo {[(4-hexyloxyphenylamino)(propylamino)-
carbene][(4-hexyloxyphenylamino)(propoxy)carbene]}
platinum(II) 4d
4.3.4. Diiodo {[(4-methoxyphenylamino)(propylamino)-
carbene][(4-methoxyphenylamino)(propoxy)carbene]}
platinum(II) 4b
Yellow powders, 79% yield. M.p. 96.9–97.6°C;
IR(KBr): 3273 w(N–H), 1552 w(CꢁN) cm−1
;
1H-
NMR (400 MHz, CDCl3): l 8.14 (s, 1H, NHAr),
7.21 (d, 2H, J=9.0 Hz, Ar), 7.31 (sb, 1H, NHAr),
7.17 (d, 2H, J=8.8 Hz, Ar), 6.85 (d, 2H, J=9.0 Hz,
Ar), 6.82 (d, 2H, J=8.8 Hz, Ar), 5.96 (sb, 1H,
NHC3H7), 5.00 (t, 2H, J=6.7 Hz, OCH2C2H5), 3.97–
3.91 (m, 4H, 2×OCH2C5H11), 3.83 (m, 2H,
NHCH2C2H5), 1.89–1.74 (m, 6H, OCH2CH2CH3+
2×OCH2CH2C4H9), 1.65 (m, 2H, NHCH2CH2CH3),
1.53–1.46 (m, 4H, 2×OC2H4CH2C2H5), 0.97 (t, 3H,
J=7.4 Hz, OC2H4CH3), 0.93–0.87 (m, 9H,
NHC2H4CH3+2×OC5H10CH3); Mass (M+) 975;
Anal. Calc. for C32H51N3O3I2Pt: C, 39.20; H, 5.08; N,
4.20; I, 25.93. Found: C, 39.43; H, 5.27; N, 4.31; I,
26.04%.
Yellow powders, 84% yield. M.p. 186.0–186.7°C;
1
IR(KBr): 3250 w(N–H), 1548 w(CꢁN) cm−1; H-NMR
(400 MHz, CDCl3): l 8.37 (bs, 1H, NHAr), 8.18 (bs,
2H, NHAr), 7.25–7.12 (m, 4H, Ar), 6.96–6.83 (m,
4H, Ar), 6.93–6.87 (m, 4H, Ar%), 5.96 (sb, 1H,
NHC3H7), 5.05 (m, 2H, OCH2C2H5), 3.83–3.79 (m,
8H, 2×OCH3+NHCH2C2H5), 1.88 (m, 2H,
OCH2CH2CH3), 1.66 (m, 2H, NHCH2CH2CH3), 0.98
(t, 3H, J=7.6 Hz, NHC2H4CH3), 0.90 (t, 3H, J=7.3
Hz, OC2H4CH3); Anal. Calc. for C22H31N3O3I2Pt: C,
31.94; H, 3.56; N, 4.83; I, 30.24. Found: C, 31.66; H,
3.75; N, 5.04; I, 30.42%.
Crystal data for 4b (Y=OCH3, R=R%=C3H7):
C22H31N3O3I2Pt, M=834.40; crystal dimensions
0.25×0.25×0.30 mm, orthorhombic, space group
˚
Pccn(c56); a=12.51(5), b=25.3(1), c=8.47(6) A,
4.3.7. Diiodo{[(4-octylphenylamino)(propylamino)-
carbene][(4-octylphenylamino)(propoxy)carbene]}
platinum(II) 4e
3
V=2684(20) A , Z=4,
D
calc=2.065
g
cm−3
,
˚
F(000)=1568.00, v(Mo–Kh)=75.34 cm−1. The data
were collected on a Rigaku AFC7R diffractometer at
−81.0°C. The structure was solved by heavy-atom
Patterson methods (PATTY) and expanded using
Fourier techniques. Hydrogen atoms were included
but not refined. The range of transmission factors is
0.667–1.000. The method used for correction is
Lorentz-polarization absorption. The final cycle of
full-matrix least-squares refinement was based on 2330
observed reflections (I\3.00|(I)) and 142 variable
parameters and converged with unweighted and
Yellow powders, 82% yield. M.p. 123.4–124.0°C;
1
IR(KBr): 3276 w(N–H), 1548 w(CꢁN) cm−1; H-NMR
(400 MHz, CDCl3): l 8.19 (bs, 2H, NHAr), 7.30–7.09
(m, 8H, Ar), 6.12 (bs, 1H, NHC3H7), 5.10 (m, 2H,
OCH2C2H5), 3.85 (m, 2H, NHCH2C2H5), 2.61 (m, 4H,
2×CH2C7H15), 1.89 (m, 2H, OCH2CH2CH3), 1.69–
1.52 (m, 6H, NHCH2CH2CH3+2×CH2CH2C6H13),
1.30–1.26 (m, 20H, 2×C2H4C5H10CH3), 1.00 (t, 3H,
J=7.4 Hz, OC2H4CH3), 0.93–0.87 (m, 9H,
NHC2H4CH3+2×C7H14CH3); Mass (M+) 999;

170
S.-W. Zhang et al. / Journal of Organometallic Chemistry 574 (1999) 163–170
Acknowledgements
Anal. Calc. for C36H59N3O1I2Pt: C, 43.45; H, 5.77; N,
4.19; I, 25.32. Found: C, 43.29; H, 5.95; N, 4.21; I,
25.41%.
We thank the Material Analysis Center of ISIR,
Osaka University for mass spectrometric and elemental
analyses.
4.3.8. Diiodo{[(4-octylphenylamino)(ethylamino)-
carbene][(4-octylphenylamino)(propoxy)
carbene]}platinum(II) 4f
References
Yellow powders, 84% yield. M.p. 130.5–131.5°C;
IR(KBr): 3297 w(N–H), 1557, 1539 w(CꢁN) cm−1
;
[1] M.H. Chisholm, H.C. Clark, Accounts Chem. Res. 6 (1973) 202,
and references cited therein.
[2] K. Oguro, M. Wada, R. Okawara, J. Organomet. Chem. 159 (1978)
417.
1H-NMR (400 MHz, CDCl3): l 8.20 (bs, 2H, NHAr),
7.25–7.13 (m, 8H, Ar), 6.04 (sb, 1H, NHC2H5), 5.29
(m, 2H, OCH2C2H5), 3.94 (m, 2H, NHCH2CH3), 2.60
(m, 4H, 2×CH2C7H15), 1.89 (m, 2H, OCH2CH2CH3),
1.55 (m, 4H, 2×CH2CH2C6H13), 1.30–1.25 (m, 23H,
NHC2H4CH3+2×C2H4C5H10CH3), 1.00 (t, 3H, J=
7.5 Hz, OC2H4CH3), 0.93–0.87 (m, 6H, 2×
C7H14CH3); Mass (M+) 985.
[3] (a) M. Keeton, R. Mason, D.R. Russell, J. Organomet. Chem. 33
(1971) 259. (b) U.T. Struchkov, G.G. Aleksandrov, S.P. Sushchin-
skaya, M.G. Voronkov, J. Organomet. Chem. 172 (1979) 269. (c)
D.J. Cardin, B. Cetinkaya, M.F. Lappert, Chem. Rev. 72 (1992)
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[4] (a) M.H. Chisholm, H.C. Clark, Inorg. Chem. 10 (1971) 1711. (b)
E.M. Badley, J. Chatt, R.L. Richards, G.A. Sim, J. Chem. Soc.,
Chem. Commun. (1969) 1322. (c) F. Bonati, G. Minghetti, J.
Organomet. Chem. 24 (1970) 251. (d) J.S. Miller, A.L. Balch, Inorg.
Chem. 11 (1972) 2069. (e) J.E. Parks, A.L. Balch, J. Organomet.
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Valle, J. Organomet. Chem. 275 (1984) 153.
[5] (a) F. Bonati, G. Minghetti, Synth. Inorg. Metal-Org. Chem. 1
(1971) 299. (b) F. Bonati, G. Minghetti, J. Organomet. Chem. 59
(1973) 403.
[6] (a) R. Ishii, T. Kaharu, N. Pirio, S.-W. Zhang, S. Takahashi, J.
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Ishii, S. Takahashi, Organometallics 16 (1997) 20.
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Takahashi, J. Organomet. Chem. 489 (1995) C62. (b) S.-W. Zhang,
R. Ishii, F. Motoori, S. Takahashi, Inorg. Chim. Acta (1997).
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4.3.9. Diiodo {[(4-(4-octylphenyl)phenylamino)(propyl-
amino)carbene][(4-(4-octylphenyl)phenylamino)
(propoxy)carbene]}platinum(II) 4g
Yellow powders, 62% yield. M.p. C---144°C---N---
173---I; IR(KBr): 3196 w(N–H), 1577 w(CꢁN) cm−1
;
1H-NMR (400 MHz, CDCl3): l 8.39 (bs, 2H, NHAr),
7.87–7.36 (m, 12H, Ar), 7.26–6.95 (m, 4H, Ar), 6.20
(bs, 1H, NHC3H7), 5.05 (m, 2H, OCH2C2H5), 4.51–
3.99 (m, 6H, 2×OCH2C7H18+NHCH2C2H5), 1.88 (m,
2H, OCH2CH2CH3), 1.52–1.44 (m, 4H, 2×
OCH2CH2C6H13), 1.30 (m, 2H, NHCH2CH2CH3),
1.07–1.02 (m, 20H, 2×OC2H4(CH2)5CH3), 0.93 (m,
3H, OC2H4CH3), 0.89–0.83 (m, 9H, NHC2H4CH3+
2×OC7H14CH3); Anal. Calc. for C48H67N3O3I2Pt: C,
48.73; H, 5.72; N, 3.55; I, 21.45. Found: C, 49.00; H,
5.74; N, 3.31; I, 21.61%.
.
.