para-Ethynyl aniline as a building block for fully π-conjugated ligands and acetylide complexes: Crystal structures of trans-[Pt(PPh3)2(C≡CC6H4NH2)2] and [(μ-H)Ru3(CO)9(μ3-C≡CC6H4NH2)]

Article abstract of DOI:10.1016/S0020-1693(00)00254-1

para-Ethynyl aniline has been prepared, structurally characterised and investigated as a building block towards fully π-conjugated multifunctional ligands and complexes. Palladium-copper catalysed coupling with aryl halides affords a number of new amino-substituted aryl acetylenes, while using [Ni(CO)₂(PPh₃)₂] as a catalyst, cyclotrimerisation and dimerisation to give an ene-yne were competitive. Reaction of para-ethynyl aniline with low-valent metal centres affords acetylide complexes trans-[Pt(PR₃)₂(C≡CC₆H₄NH₂)₂] (R = Ph, Bu(n)), cis-[Pt(η²-dppe)(C≡CC₆H₄NH₂)₂], all trans-[Ru(CO)₂(PEt₃)₂(C≡CC₆H₄NH₂)₂] and [(μ-H)Ru₃(CO)₉(μ₃C≡CC₆H₄NH₂)]. The bis(acetylide) trans-[Pt(PPh₃)₂(C≡CC₆H₄NH₂)₂] has been used to prepare extended chain complexes with amide, imine, imino-phosphorane and ferrocenyl imine units being generated. Attempts to prepare polymers via reaction with terephthaloyl chloride lead only to the formation of oligomers with an average of four monomer units. (C) 2000 Elsevier Science B.V.

Full text of DOI:10.1016/S0020-1693(00)00254-1

www.elsevier.nl/locate/ica
Inorganica Chimica Acta 309 (2000) 109–122
para-Ethynyl aniline as a building block for fully p-conjugated
ligands and acetylide complexes: crystal structures of
trans-[Pt(PPh3)2(CꢀCC6H4NH2)2] and
[(m-H)Ru3(CO)9(m3-CꢀCC6H4NH2)]
Antony J. Deeming a, Graeme Hogarth a,*, Mo-yin (Venus) Lee a, Malini Saha a,
Simon P. Redmond a, Hirihattaya (Taya) Phetmung b, A. Guy Orpen b
a Department of Chemistry, Uni6ersity College London, 20 Gordon Street, London, WC1H 0AJ, UK
b Department of Chemistry, Uni6ersity of Bristol, Bristol, BS8 1TS, UK
Received 24 March 2000; accepted 26 June 2000
Abstract
para-Ethynyl aniline has been prepared, structurally characterised and investigated as a building block towards fully
p-conjugated multifunctional ligands and complexes. Palladium–copper catalysed coupling with aryl halides affords a number of
new amino-substituted aryl acetylenes, while using [Ni(CO)2(PPh3)2] as a catalyst, cyclotrimerisation and dimerisation to give an
ene-yne were competitive. Reaction of para-ethynyl aniline with low-valent metal centres affords acetylide complexes trans-
[Pt(PR3)2(CꢀCC6H4NH2)2] (R=Ph, Bun), cis-[Pt(h2-dppe)(CꢀCC6H4NH2)2], all trans-[Ru(CO)2(PEt3)2(CꢀCC6H4NH2)2] and [(m-
H)Ru3(CO)9(m3-CꢀCC6H4NH2)]. The bis(acetylide) trans-[Pt(PPh3)2(CꢀCC6H4NH2)2] has been used to prepare extended chain
complexes with amide, imine, imino-phosphorane and ferrocenyl imine units being generated. Attempts to prepare polymers via
reaction with terephthaloyl chloride lead only to the formation of oligomers with an average of four monomer units. © 2000
Elsevier Science B.V. All rights reserved.
Keywords: Acetylide; Platinum complexes; p-Conjugated; Anilines
of a range of fully p-conjugated ligands leading to
multimetallic arrays. It is planar showing strong p-or-
bital overlap and thus potential extended p-conjugation
with metal centres and contains four possible reactivity
sites; (a) the acetylenic hydrogen; (b) alkyne; (c) arene;
and (d) amine, each capable of binding different types
of metal centres. For example, para-ethynyl aniline has
the potential to bind a low-valent metal centre in an
acetylenic fashion and a high-valent centre as an imido
complex thus allowing strong communication between
electronically divergent metal centres. Herein we report
studies of the chemistry of para-ethynyl aniline which
have focused primarily on its development as an
acetylide source. These include the synthesis of a num-
ber of new amino-substituted aryl acetylenes via cop-
per–palladium catalysed coupling reactions with aryl
halides, mono- and bis(acetylide) complexes of low-va-
lent transition metals and complexes in which the
1. Introduction
Ligands containing a number of different types of
metal binding sites are potentially useful building
blocks towards the synthesis of multimetallic arrays.
Further, if binding sites are electronically conjugated,
this may allow communication between diverse metal
centres and the development of new metallic systems of
academic interest and with potential applications in
new device technology.
para-Ethynyl aniline (1) [1,2] is a simple organic
molecule, relatively easy to prepare and handle, which
has potential as a building block towards the synthesis
* Corresponding author. Tel.: +44-171-504 4664; fax: +44-171-
380 7463.
E-mail
addresses:
g.hogarth@ucl.ac.uk
(G.
Hogarth),
guy.orpen@bristol.ac.uk (A.G. Orpen).
0020-1693/00/$ - see front matter © 2000 Elsevier Science B.V. All rights reserved.
PII: S0020-1693(00)00254-1

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A.J. Deeming et al. / Inorganica Chimica Acta 309 (2000) 109–122
amino groups of the latter have been utilised to prepare
extended conjugated chain complexes.
The coupling of primary alkynes and aryl halides
using [PdCl2(PPh3)2]–CuI as a catalyst is well-docu-
mented [3] and provides a useful route to new disubsti-
tuted alkynes. We have utilised this methodology in
order to couple para-ethynyl aniline 1 to a range of aryl
halides (Scheme 2). Yields of new alkynes 2–6 were
between 28 and 66%, products being isolated as yellow
or orange solids. With 1,2-diiodobenzene, a side-
product was the monosubstituted arene 5 (50%), while
with 1,2,4,5-tetrabromobenzene and hexabromobenzene
no tractable products were isolated. We also attempted
the homo-coupling of 1 in order to produce a diyne
following literature procedures using copper(II) acetate
in a methanol–pyridine mixture [4] and also via use of
a catalytic amount of a copper(I) salt [5]. Neither set of
conditions proved ideal as a mixture of unreacted 1 and
a second compound (presumed to be the diyne) were
always produced. As water might have a detrimental
effect on the coupling reaction, a reaction was carried
out in dry pyridine and this yielded diyne 7 as an
orange powder in 14% yield. Product characterisation
was generally straightforward. All gave molecular ions
2. Results and discussion
para-Ethynyl aniline (1) was prepared in a three step
sequence as described by Melissaris and Litt [1] starting
from para-iodo aniline (Scheme 1). In our hands overall
yields were around 50%, the most problematic step
being the flash chromatography at 0°C after deprotec-
tion. As the product was not very soluble in
dichloromethane it was placed on the column as a
suspension and sometimes this became blocked result-
ing in a colour change from pale yellow to brown and
a much decreased yield. The product was stored in the
freezer and used as required. It is easily identifiable
spectroscopically, the w(CꢀC) stretch appearing at 2098
cm−1 in the IR spectrum, while in the 1H NMR
spectrum a sharp singlet at l 2.95 is assigned to the
acetylenic proton and a broad resonance at l 3.8 to the
amine functionality. Large off-white crystals were
grown upon slow cooling of a hot toluene solution and
these proved suitable for X-ray analysis the results of
which are shown in Fig. 1. The molecule (Fig. 1(a))
contains a mirror plane which includes the amine and
alkyne substituents and bisects the arene ring. Hydro-
gen atoms were located from difference maps and all
atoms except the protons on nitrogen lie in a plane as
expected. It packs in a regular zig-zag pattern (Fig.
1(b)), with one array of molecules lying perpendicular
to the next and the amine groups of one layer pointing
towards those of the neighbouring layer. There are no
short intermolecular interactions.
1
in the mass spectrum and H NMR data were particu-
larly informative. The amine protons appear as a broad
resonance around l 3.8, while in the aryl region pro-
tons ortho to the amine group are found at characteris-
tic high fields, l 6.70–6.60.
A range of transition metal complexes are known to
act as catalysts for the cyclotrimerisation of alkynes,
with Ni(II) and Ni(0) catalysts being particularly active
[6]. The nickel(II) complex [NiCl2(PPh3)2] was not an
effective catalyst for the cyclotrimerisation of para-eth-
ynyl aniline, the unreacted alkyne being recovered even
after prolonged thermolysis. In contrast, in the presence
Scheme 1. Synthesis of para-ethynyl aniline.

A.J. Deeming et al. / Inorganica Chimica Acta 309 (2000) 109–122
111
,
Fig. 1. Molecular structure of para-ethynyl aniline (1) with selected bond lengths (A) and angles (°): C(1)ꢁN(1) 1.383(5), C(1)ꢁC(2) 1.375(5),
C(2)ꢁC(3) 1.386(4), C(3)ꢁC(4) 1.372(4), C(4)ꢁC(5) 1.437(4), C(5)ꢁC(6) 1.180(5), N(1)ꢁC(1)ꢁC(2) 121.0(2), C(1)ꢁC(2)ꢁC(3) 120.7(3), C(2)ꢁC(3)ꢁC(4)
121.5(3), C(3)ꢁC(4)ꢁC(4A) 117.5(3), C(3)ꢁC(4)ꢁC(5) 121.2(2), C(4)ꢁC(5)ꢁC(6) 179.4(3).
evidence for ene-ynes. Recently, the nature of this
reaction has been shown to be sensitive to conditions
employed, the solvent-free reaction affording a mixture
of cyclotrimers and polymer, but again no ene-yne [8].
Mechanistic details are fairly well-understood with oxi-
dative-addition of the CꢁH bond known to occur to
afford a Ni(II) hydridoꢁalkynyl intermediate, which is
prone to further alkyne insertion into the
nickelꢁalkynyl bond. Reductive-elimination forming a
new CꢁH bond terminates the chain growth and it is
the rate of this step as compared to the rate of alkyne
insertion into the alkynyl moiety which determines the
nature of the products. Clearly with 1, generation of
approximately equimolar amounts of ene-yne and arene
suggests that these processes have similar rates and are
thus competitive. The regioselective formation of ene-
yne 9 is a result of the regioselectivity of insertion of 1
into the alkynyl intermediate and results from steric
of the nickel(0) complex, [Ni(CO)2(PPh3)2], alkyne con-
sumption occurred over 4 h as monitored by IR spec-
troscopy,
yielding
after
chromatography
in
approximately equal amounts of the anticipated trisub-
stituted arene 8 and the ene-yne 9, a product of alkyne
dimerisation. On the basis of complexity of the aryl
1
region of the H NMR spectrum of 8, we believe it to
be a mixture of 1,2,4- and 1,3,5-isomers, 8a and 8b,
respectively, although we cannot determine the relative
amounts. Ene-yne 9 results from the regioselective
dimerisation of 1 and is easily characterised by 1H
NMR spectroscopy. The trans-arrangement of olefinic
protons is shown by a coupling constant of 16.2 Hz,
while the aromatic protons are seen as two pairs of
doublets showing that the arene rings are inequivalent.
In earlier work the reaction of phenylacetylene in
benzene with [Ni(CO)2(PPh3)2] was shown to yield both
cyclo- and linear-trimerisation products [7] with no

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A.J. Deeming et al. / Inorganica Chimica Acta 309 (2000) 109–122
control. Ene-ynes have previously been reported to
result from metal-catalysed dimerisation of primary
alkynes [9], although the catalysts employed normally
contain early transition metals [10].
CPh)2] has not been crystallographically characterised,
although its cis-isomer has been the subject of an X-ray
study [13] and there appear to be no significant differ-
ences in the structural parameters of this and 10.
Synthesis of cis-[Pt(h2-dppe)(CꢀCC6H4NH2)2] (12)
was not as straight-forward as the trans-complexes
10–11. An initial attempt was made using the same
methodology, namely via reaction of cis-[PtCl2(h2-
dppe)] with 1 in the presence of CuCl–Et2NH. An
orange precipitate was obtained but this was shown by
31P NMR to contain some unreacted 10, while the FAB
mass spectrum showed an ion at m/z 887 consistent
with the incorporation of Cu+ into the complex. The
binding of copper(I) to bis(acetylide) units is well-
known [15] and thus in order to avoid this complication
an alternative route to 12 was sought. The successful
synthesis of 12 as a yellow powder (36%) was accom-
plished upon deprotonation of 1 with butyllithium fol-
lowed by reaction with cis-[PtCl2(h2-dppe)]. The
somewhat smaller PtꢁP coupling of 2257 Hz in the 31P
NMR spectrum is indicative of a cis-acetylide arrange-
ment. In order to extend the synthesis of para-
aminoethynyl ligands to other low-valent centres and in
a manner analogous to that developed by Carty et al.
[16], deprotonated 1 was reacted with all trans-
A goal of our work was to incorporate metal centres
into potentially fully p-conjugated ligand systems and
this was achieved using para-ethynyl aniline 1 as an
acetylide source to incorporate low-valent metal centres
(Scheme 3). Reaction of trans-[PtCl2(PR3)2] (R=
Ph,nBu) with two equivalents of 1 in the presence of
CuI and base afforded bis(acetylide) complexes trans-
[Pt(PR3)2(CꢀCC6H4NH2)2] 10–11 in 80–90% yield.
Characterisation proved straight-forward and single
crystals of 10 (R=Ph) suitable for X-ray crystallogra-
phy were grown upon cooling of a saturated chloroben-
zene solution, the results of which are shown in Fig. 2.
The molecule has an inversion centre and shows the
expected trans arrangement of acetylides. The short
,
C(1)ꢁC(2) bond of 1.206(6) A is within the range found
in related Pt(II) acetylide complexes [11–14] is the
,
Pt(1)ꢁP(1) bond of 2.310(1) A. The acetylide ligand is
essentially linear [Pt(1)ꢁC(1)ꢁC(2) 177.00(37),
C(1)ꢁC(2)ꢁC(3) 175.24(46)°] and the bond angle be-
tween the phosphine and acetylide ligands,
P(1)ꢁPt(1)ꢁC(1) 88.83(12)°, is as expected for a square-
planar Pt(II) centre. The molecule co-crystallises with
chlorobenzene but there are no short intermolecular
contacts. As far as we are aware, the unsubstituted
trans phenylacetylide complex trans-[Pt(PPh3)2(Cꢀ
[RuCl2(CO)2(PEt3)2]
to
give
all
trans-[Ru-
(CO)2(PEt3)2(CꢀCC6H4NH2)] 13 as a sticky orange
solid in ca. 25% yield after chromatography. We were
Scheme 2. (i)–(iv) CuI–PdCl2(PPh3)2–NEt3; (i) para-IC6H4NH2; (ii) 1,2-IC6H4I; (iii) 1,4-C6H4I2; (iv) 1,3,5-C6H3Br3; (v) CuI–py–O2; (vi)
Ni(CO)2(PPh3)2.

A.J. Deeming et al. / Inorganica Chimica Acta 309 (2000) 109–122
113
Scheme 3. (i) trans-[PtCl2(PR3)2]–CuI–NEt2H; (ii) cis-[PrCl2(dppe)]–BuLi; (iii) all trans-[RuCl2(CO)2(PEt3)2]–BuLi; (iv) [Ru3(CO)12], 95°C; (v)
HBF4·Et2O or CF3CO2H; (vi) Ph3PBr2–NEt3.
,
Fig. 2. Molecular structure of trans-[Pt(PPh3)2(CꢀCC6H4NH2)2] (10) with selected bond lengths (A) and angles (°): Pt(1)ꢁP(1) 2.310(1), Pt(1)ꢁC(1)
2.005(4), C(1)ꢁC(2) 1.206(6), C(2)ꢁC(3) 1.449(6), N(1)ꢁC(6) 1.395(6), P(1)ꢁPt(1)ꢁC(1) 88.83(12), Pt(1)ꢁC(1)ꢁC(2) 177.00(37), C(1)ꢁC(2)ꢁC(3)
175.24(46).
unable to get an analytically pure sample of 13 and
characterisation was based on the observation of strong
CꢀC and CO bands in the IR spectrum at 2035 and
1972 cm−1, respectively.
Reaction of 1 with [Ru3(CO)12] affords a probe of the
relative reactivity of the different metal binding sites of
1 as acetylide [17], amide and imido [18], acetylene [19]
and arene [20] complexes can all potentially result.
Heating a heptane solution of [Ru3(CO)12] and 1 for 4
h resulted in complete reaction as shown by IR spec-
troscopy and the isolation after chromatography of the
acetylide complex [(m-H)Ru3(CO)9(m3-CꢀCC6H4NH2)]
(14) in moderate yield. Single crystals suitable for X-ray
crystallography were grown upon slow cooling of a

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A.J. Deeming et al. / Inorganica Chimica Acta 309 (2000) 109–122
1
saturated hexane solution, the results of which are
given in Fig. 3. The ruthenium triangle is capped by the
5-electron acetylide ligand, the a-carbon of which binds
to all three metal centres [Ru(1)ꢁC(10) 1.969(4),
(15). This was ascertained from both IR and H NMR
studies, the latter being most informative. Thus, upon
addition of CF3CO2H to a CDCl3 solution the amine
protons shifted downfield from l 3.89 to 6.20, the latter
integrating as three protons and although the hydride
resonance also shifted downfield significantly, from l
−20.41 to −6.47, it still integrated as one proton.
Haymore et al. have previously shown that
[Mo(NPh)Cl2(h2-S2CNEt2)2] can be prepared upon re-
action of [MoOCl2(h2-S2CNEt2)2] with Ph3PꢂNPh [22].
In an attempt to synthesise a related alkynyl-substituted
,
Ru(2)ꢁC(10) 2.221(4), Ru(3)ꢁC(10) 2.224(4) A], while
the b-carbon spans the Ru(2)ꢁRu(3) vector
,
[Ru(2)ꢁC(11) 2.318(4), Ru(3)ꢁC(11) 2.297(4) A]. The
latter is also bridged by a hydride which lies ca. trans-
to the a-carbon of the acetylide. As expected, the
acetylenic bond is elongated upon p-coordination [14,
,
C(10)ꢁC(11) 1.314(6); 10, C(1)ꢁC(2) 1.206(6) A] and
also deviates significantly from linearity [14,
C(10)ꢁC(11)ꢁC(12) 145.5(4); 10, C(1)ꢁC(2)ꢁC(3)
175.24(46)°]. The para-aminophenyl substituent lies ap-
proximately perpendicular to a plane which includes
Ru(1)ꢁC(10) and C(11) and bisects Ru(2) and Ru(3)
and the nitrogen is pyramidal as expected. General
structural features of the M3(m3-h2-perpendicular)
acetylide ligand are as found in related trinuclear
Group 8 complexes [21] and the parent acetylide com-
plex [(m-H)Ru3(CO)9(m3-CꢀCH)] [19]. Cluster 14 has a
number of possible protonation sites, namely, across a
metal–metal vector or at the amine functionality. In
order to determine the preferred site, protonation stud-
ies were carried out and resulted in the formation of the
ammonium salt [(m-H)Ru3(CO)9(m3-CꢀCC6H4NH3)][X]
molybdenum
imido
complex
we
prepared
Ph3PꢂNC6H4CꢀCH (16) in quantitative yield upon re-
action of para-ethynyl aniline with Ph3PBr2. Further
reaction of 16 with [MoOCl2(h2-S2CNEt2)2] in refluxing
toluene resulted in the formation of a deep red solution,
however, no pure product could be isolated. The IR
spectrum showed a strong peak at 1277 cm−1 indica-
tive of a the formation of a molybdenum imido com-
1
plex, but the H NMR spectrum was complex due and
all attempts to remove Ph3PO were unsuccessful. Direct
reaction of 1 and [MoOCl2(h2-S2CNEt2)2] in methanol
also afforded a dark red product with similar spectral
properties, but again no pure product could be isolated.
We have recently shown that a range of anilines react
with [MoOCl2(h2-S2CNEt2)2] to afford seven coordi-
,
Fig. 3. Molecular structure of [(m-H)Ru3(CO)9(m3-CꢀCC6H4NH2)] (14) with selected bond lengths (A) and angles (°): Ru(1)ꢁRu(2) 2.8163(11),
Ru(2)ꢁRu(3) 2.8113(10), Ru(1)ꢁRu(3) 2.8092(9), Ru(1)ꢁC(10) 1.969(4), Ru(2)ꢁC(10) 2.221(4), Ru(3)ꢁC(10) 2.224(4), Ru(2)ꢁC(11) 2.318(4),
Ru(3)ꢁC(11) 2.297(4), C(10)ꢁC(11) 1.314(6), C(11)ꢁC(12) 1.458(6), N(1)ꢁC(15) 1.402(6), Ru(1)ꢁRu(2)ꢁRu(3) 59.89(3), Ru(2)ꢁRu(3)ꢁRu(1)
60.14(3), Ru(3)ꢁRu(1)ꢁRu(2) 59.97(2), Ru(1)ꢁC(10)ꢁRu(3) 83.9(2), Ru(2)ꢁC(10)ꢁRu(3) 78.45(13), Ru(3)ꢁC(11)ꢁRu(2) 75.05(13),
C(10)ꢁC(11)ꢁC(12) 145.5(4).

A.J. Deeming et al. / Inorganica Chimica Acta 309 (2000) 109–122
115
Scheme 4. (i) Benzoyl chloride–NEt3; (ii) terephthaloyl chloride–NEt3; (iii) cyclohexanone–MgSO4; (iv) [Fe(C5H4CHO)(C5H5)]–MgSO4; (v)
Ph3PBr2–NEt3.
nate Mo(VI) imido complexes [Mo(NAr)Cl2(h2-
S2CNEt2)2] the majority of which are obtained as red
solids [23]. It seems likely that related alkynyl-substi-
tuted aryl imido complexes are being prepared here but
further attempts at purification were not made.
As the bis(acetylide) complex trans-[Pt(PPh3)2-
(CꢀCC6H4NH2)2] (10) is easily prepared it seemed a
potentially useful building block for the synthesis of
long chain compounds (Scheme 4). Accordingly, reac-
tion with two equivalents of benzoyl chloride in the
monomer units (1072 g). Thus it appears that only
oligomerisation has occurred and this is probably a
consequence of poor solubility. In an attempt to com-
bat this the more soluble bis(acetylide) complex trans-
[Pt(PnBu3)2(CꢀCC6H4NH2)2] (11) was reacted with
terephthaloyl chloride in a similar manner. Again a
precipitate 20 resulted which was shown to contain
1.86% of chlorine leading to a similar average molecu-
lar weight of ca. 4050 g. This solid was sparingly
soluble in DMF making it possible to run a 31P NMR
spectrum which showed a triplet at 4.02 (JPtꢁP 2361 Hz)
ppm.
Ketones and aldehydes are known to react with
amines to yield imines after removal of water. Heating
10 and cyclohexanone in presence of MgSO4 afforded
orange–brown trans-[Pt(PPh3)2(CꢀCC6H4NꢂC6H10)2]
(20) in 43% yield. Again the 31P NMR spectrum
showed two sets of signals but in a 4:1 ratio suggesting
that the ‘up-down’ configuration may be preferable to
the ‘up-up’ configuration on steric grounds. In the mass
spectrum a molecular ion was observed at m/z 1112.
Incorporation of ferrocene into molecular wires has
been widely studied as the redox chemistry of the iron
centres can be used to probe electronic communication
[24]. Addition of two equivalents of [Fe(h5-
C5H4CHO)(h5-C5H5)] to 10 resulted in the clean forma-
tion of trans-[Pt(PPh3)2(CꢀCC6H4NꢂCHꢁFc)2] (21) as
presence
of
base
afforded
trans-[Pt(PPh3)2-
{CꢀCC6H4NHC(O)Ph}2] (17) in 92% yield. In the 31P
NMR spectrum two signals of approximately equal
intensity were observed at 28.2 (JPtꢁP 2651) and 27.7
(JPtꢁP 3000 Hz) ppm and these are attributed to rac
(+ +) and meso (+ −) conformations at nitrogen.
Similarly, two carbonyl absorptions are seen in the IR
1
spectrum, although in the H NMR spectrum only a
single pair of aromatic doublets is observed. Attempts
to prepare polymers based on the above methodology
was not successful. Reaction of terephthaloyl chloride
and 10 afforded an insoluble yellow powder 18 in 65%
yield. In the FAB mass spectrum the highest peak was
at m/z 919 and by TOFSPEC 1101. Elemental analysis
showed 2.09% of chlorine and based on the assumption
that the ends of all molecules have a chlorine atom then
the average molecular weight is ca. 3400 g, i.e. four

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A.J. Deeming et al. / Inorganica Chimica Acta 309 (2000) 109–122
an orange solid in 63% yield. Incorporation of two
ferrocene units was clear from the H NMR and FAB
performed in the Chemistry Department of University
College London. para-Iodoaniline was purchased from
Lancaster and 1,2- and 1,4-diiodobenzene, 1,3,5-tribro-
mobenzene, 2-methyl-3-butyn-2-ol and Ph3PBr2 from
Aldrich. Metal complexes [PdCl2(PPh3)2] [25],
[Ni(CO)2(PPh3)2] [26], [PtCl2(PPh3)2] [27], [PtCl2-
(PnBu3)2] [28], [PtCl2(h2-dppe)] [29], [Ru(CO)2-
(PEt3)2Cl2] [30], [MoOCl2(h2-S2CNEt2)2] [31] and
[Fe(h5-C5H4CHO)(h5-C5H5)] [32] were prepared via lit-
erature methods.
1
mass spectra, the latter showing a molecular ion at m/z
1344. The phosphorus imine trans-[Pt(PPh3)2-
(CꢀC6H4C6H4NꢂPPh3)2] (22) was prepared in 65% yield
upon reaction with two equivalents of Ph3PBr2. In an
attempt to coordinate high-valent metal centres to the
Pt(II) centre, 10 was reacted with a slight excess of
[MoOCl2(h2-S2CNEt2)2]; however, results were incon-
clusive. An orange–brown solid was obtained which we
could not fully characterise. In the IR spectrum a
strong band at 1278 cm−1 showed that imido forma-
tion had occurred, while the 31P NMR spectrum gave a
4.2. Synthesis of N-trifluoroacetyl-4-iodoaniline
1
signal at 21.2 (JPtꢁP 3266 Hz) ppm. However, H NMR,
para-Iodoaniline (24.98 g, 0.114 mol) was placed in a
250 cm3 round bottom flask and this was flushed with
nitrogen and dried thf (150 cm3) was added by syringe.
The mixture was stirred until a nitrogen atmosphere
until all solid had dissolved. Trifluoroacetic anhydride
(31.87 g, 0.228 mol) was added dropwise via syringe at
0°C over 20 min and the mixture stirred overnight at
room temperature. Removal of volatiles under reduced
pressure gave an off-white solid which was washed with
2×120 cm3 of water, filtered and dried under vacuum.
N-Trifluoroacetyl-4-iodoaniline was obtained as off-
white flakes (36.97 g, 99% yield). M.p. 141.5–141.7°C;
1H NMR (CDCl3) l 7.84 (bs, 1H, NH), 7.76 (d, J 8.6,
2H, Ar), 7.34 (d, J 8.6, 2H, Ar).
mass spectral and analytical data proved confusing and
this was not pursued further.
3. Conclusions
We have shown in this contribution that para-eth-
ynyl aniline is a useful building block towards the
synthesis of fully p-conjugated multifunctional ligands,
including those which contain Pt(II) bis(acetylide) cen-
tres. Coordination of high-valent transition metals to
the amino groups via an imido linkage has proved more
problematic. One of the major drawbacks towards this
approach to building multifunctional molecules con-
taining both low- and high-valent metal centres and the
synthesis of fully p-conjugated metal containing poly-
mers is the insolubility of compounds formed. This is
almost certainly a function of the rigidity of the rod-
like chains and may be overcome by incorporating
alkyl phosphines into the chains. Early work in this
direction focused on the use of n-butyl phosphine and
while somewhat disappointing, is currently being pur-
sued. On a more positive note, coordination of techno-
logically important ferrocene units via an imine linkage
occurred cleanly to give a soluble and stable complex
and suggests that polymers may be accessible based on
this approach. In this regard we are currently exploring
the reactions of bis(aminoacetylide) complexes with
ferrocene dialdehyde and disubstituted ferrocenes with
groups known to react with primary amines.
4.3. Synthesis of 4-{N-(trifluoroacetyl)anilin-4-yl}-
2-methyl-3-butyn-2-ol
N-Trifluoroacetyl-4-iodoaniline (36.97 g, 0.117 mol),
PPh3 (0.74 g, 2.82 mmol), copper(I) iodide (0.19 g, 1.02
mmol) and 2-methyl-3-butyn-2-ol (25.04 g, 0.298 mol)
were placed into a two-necked 500 cm3 round bottom
flask and 250 cm3 of dry Et3N was added. An air-con-
denser was fitted and the mixture heated to 50°C under
a nitrogen atmosphere. Solid [PdCl2(PPh3)2] (0.195 g,
0.277 mol) was added and the reaction heated at 50°C
for 20 min and at reflux for a further 20 min. Cooling
to room temperature gave a yellow solution with a
copious precipitate. Diethyl ether (75 cm3) was added
and the mixture filtered to leave a white solid. The solid
was washed with a further 75 cm3 of diethyl ether and
the filtrates were combined. Removal of volatiles under
reduced pressure gave a viscous oil which was dried
further under vacuum overnight. Acetic acid (100 cm3)
was added in an ice-bath and the mixture left to stir at
room temperature producing a brown solution. This
was evaporated to produce a sticky red–brown solid.
Distilled water (300 cm3) was added and the mixture
stirred to give an orange solid and yellow solution
which was filtered. The product was crystallised from
hot toluene to give a yellow solid which was dissolved
in ca. 400 cm3 of dichloromethane (after ca. 3 h stir-
ring). This was then extracted with 3×120 cm3 of
4. Experimental
4.1. General
Unless otherwise stated, dried and degassed solvents
were used in all reactions. NMR spectra were recorded
on Bruker AC300 (1H) or Varian VXR400 (1H and 31P)
spectrometers, IR spectra on a Nicolet 205 FTIR spec-
trometer and mass spectra on a VG 7070 high resolu-
tion mass spectrometer. Elemental analyses were

A.J. Deeming et al. / Inorganica Chimica Acta 309 (2000) 109–122
117
water and the organic layer was dried with MgSO4 and
4.6. Synthesis of
evaporated to dryness to afford 4-{N-(trifluoro-
1,4-bis(2-(4-aminophenyl)ethynyl)benzene (3)
acetyl)anilin-4-yl}-2-methyl-3-butyn-2-ol as a yellow
1
solid (31.83 g, 99%). H NMR (CDCl3) l 7.53 (d, J 8.6,
The reaction was carried out in an analogous fashion
to that described above using 1 (0.58 g, 4.96 mmol) and
1,4-diiodobenzene (0.82 g, 2.48 mmol). Elution with
dichloromethane–acetone (1:1) gave a very slow mov-
ing yellow band which afforded orange 3 (0.70 g, 55%).
Recrystallisation from hot toluene afforded orange
2H, Ar), 7.42 (d, J 8.6, 2H, Ar), 1.60 (s, 6H, Me).
4.4. Synthesis of para-ethynyl aniline (1)
KOH pellets (16.44 g, 0.29 mol) was added to 200
1
needles. IR (KBr) 3361 (NH), 2206 (CꢀC) cm−1; H
cm3 of PrOH in a flask connected to a water condenser
i
NMR (CDCl3) l 7.46 (s, 4H, Ar), 7.35 (d, J 8.5, 4H,
Ar), 6.65 (d, J 8.5, 4H, Ar), 3.85 (brs, 4H, NH2); 13C
NMR (CDCl3) 146.8, 133.0, 131.2, 123.1, 114.7, 112.4,
91.8, 87.3 ppm; mass spectrum (EI): m/z 308 (M+).
Elemental analysis: Anal. Found: C, 85.12; H, 5.65; N,
8.82. Calc. for C22H16N2, C, 85.71; H, 5.19; N, 9.09%.
and brought to reflux. 4-{N-(trifluoroacetyl)anilin-4-
yl}-2-methyl-3-butyn-2-ol (31.83 g, 0.117 mol) was
added to the refluxing solution and the mixture heated
for 2.5 h. After cooling to room temperature the sol-
vent was removed under reduced pressure to give a
brown solid which was washed with 2×80 cm3 of cold
hexane. The resulting brown solid was taken up in
dichloromethane (400 cm3) and stirred for 1 h although
all solids did not dissolve. The resulting slurry was
poured onto a short (ca. 2 cm) ice-cooled silica column
made up with dichloromethane and eluted with more
dichloromethane until the eluent was colourless. Yellow
and orange bands were collected separately and solvent
removed to afford a fine yellow powder and sticky
orange solid respectively. Both were shown by 1H
NMR to be para-ethynyl aniline (1) (combined yield
7.44 g, 54%). IR (KBr) 3486 (NH), 3389, 3260, 2098
4.7. Synthesis of
1,2-bis(2-(4-aminophenyl)ethynyl)benzene (4) and
1-(2-iodophenyl)-2-(4-aminophenyl)ethyne (5)
The reaction was carried out in an analogous fashion
using 1 (0.50 g, 4.27 mmol) and 1,2-diiodobenzene (0.71
g, 2.14 mmol). Elution with light petroleum–di-
ethylether (1:2) gave a yellow band which afforded 5
(0.34 g, 50%) as a pale yellow solid. IR (KBr) 2211
(CꢀC), 1560 (NH2), 500 (CꢁI) cm−1; 1H NMR (CDCl3)
l 7.88 (dd, 1H, J 8.0, 1.1, 1H, Ar), 7.51 (dd, J 7.8, 1.7,
1H, Ar), 7.43 (d, J 8.7, 2H, Ar), 7.32 (dd, J 7.6, 1.2, 1H,
Ar), 6.99 (dd, J 7.8, 1.7, 1H, Ar), 6.66 (d, J 8.7, 2H,
Ar), 3.95 (brs, 2H, NH2); mass spectrum (EI): m/z 319
(M+). Elution with diethyl ether–dichloromethane
(1:1) gave an orange band which afforded 4 (0.29 g,
44%) as an oily orange solid. IR (KBr) 2210 (CꢀC),
(CꢀC) cm−1; H NMR (CDCl3) l 7.30 (d, J 9.0, 2H,
1
Ar), 6.60 (d, J 9.0, 2H, Ar), 3.79 (brs, 2H, NH2), 2.95
(s, 1H, HCꢀC); mass spectrum (EI): m/z 117 (M+).
Single crystals suitable for X-ray diffraction were
grown upon slow cooling of a saturated warm toluene
solution.
1
1560 (NH2) cm−1; H NMR (CDCl3) l 7.52 (dd, J 6.0,
4.5. Synthesis of 4,4%-diaminodiphenylethyne (2)
3.5, 2H, Ar), 7.39 (d, J 7.9, 4H, Ar), 7.25 (dd, J 5.9, 3.5,
2H, Ar), 6.63 (d, J 7.9, 4H, Ar), 3.92 (brs, 4H, NH2);
mass spectrum (EI): m/z 308 (M+).
para-Iodoaniline (0.78 g, 3.56 mmol), copper(I) io-
dide (0.01 g, 0.06 mmol) and 1 (0.50 g, 4.27 mmol) were
placed in a schlenk tube and dry NEt3 (40 cm3) was
added via cannula. [PdCl2(PPh3)2] (0.05 g, 0.07 mmol)
was added to this solution which was rigorously de-
gassed and stirred at room temperature overnight.
Volatiles were removed under reduced pressure and the
resulting yellow–brown solid was extracted with 2×50
cm3 of benzene. This was placed on an alumina chro-
matography column made up with hexane–benzene
(3:2). Elution with dichloromethane afforded a pale
yellow band which gave 2 as a yellow powder (0.21 g,
28%). This was recrystallised from hot benzene to af-
ford yellow needles. IR (KBr) w(NH) 3405, 3295, 3195
4.8. Synthesis of
1,3,5-tris(2-(4-aminophenyl)ethynyl)benzene (6)
Reaction was carried out as above using 1 (1.00 g,
8.54 mmol) and 1,3,5-tribromobezene (0.67 g, 2.14
mmol). The mixture was heated to 50°C for 10 h to give
a dark brown solid after removal of volatiles. Elution
with diethyl ether–dichloromethane (1:4) gave a yellow
band which afforded 6 (0.59 g, 66%) as an oily yellow
solid. This was washed with light petroleum to give a
somewhat less oily solid. IR (KBr) 3400 (NH), 2250
1
(CꢀC), 1620 (NH2) cm−1; H NMR (CDCl3) l 7.59 (s,
1
cm−1; H NMR (CDCl3) l 7.31 (d, J 8.3, 4H, Ar), 6.63
3H, Ar), 7.37 (d, J 8.4, 6H, Ar), 6.64 (d, J 8.4, 6H, Ar),
3.88 (brs, 6H, NH2); mass spectrum (EI): m/z 423
(M+). Elemental analysis: Anal. Found: C, 72.83; H,
5.04; N, 7.36. Calc. for C30H21N3·CH2Cl2, C, 73.23; H,
4.45; N, 8.27%.
(d, J 8.3, 4H, Ar), 3.78 (brs, 4H, NH2); mass spectrum
(EI): m/z 208 (M+). Elemental analysis: Anal. Found:
C, 79.80; H, 5.75; N, 13.06. Calc. for C14H12N2, C,
80.77; H, 5.77; N, 13.46%.

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A.J. Deeming et al. / Inorganica Chimica Acta 309 (2000) 109–122
4.9. Synthesis of 1,4-bis(4-aminophenyl)buta-1,3-diyne
(7)
diethylamine (40 cm3) was added by cannula. Copper(I)
iodide (10 mg) was added and the mixture was stirred
overnight at room temperature resulting in the slow
formation of a yellow precipitate. After removal of
volatiles the resulting yellow solid was washed with
water and air-dried to give 10 (0.53 g, 88%) as a fine
yellow powder. Recrystallisation from dichloromethane
gave yellow flakes while from chlorobenzene dark
brown blocks formed which were suitable for X-ray
crystallography. IR (KBr) 3432 (NH), 3325 (NH), 2105
Copper(I) chloride (0.54 g, 2.73 mmol) was placed in
a three-necked round bottom flask equipped with a stir
bar, water condenser and an adaptor connected to an
oxygen source. Pyridine (50 cm3) was added and the
mixture warmed in a water bath to 40°C while bubbling
oxygen vigorously through the solution until after 20
min a dark green solution was obtained. 1 (0.89 g, 7.57
mmol) was added to the solution and the reaction
mixture was stirred for 1.5 h at 40°C with oxygen
bubbling. The mixture became black and quite viscous
and after 2.5 h gave a black solid. Dilute ammonium
hydroxide (200 cm3) was added in several portions
giving a blue filtrate. The solid was washed with ammo-
nium hydroxide solution until the filtrate was colourless
1
(CꢀC) cm−1; H NMR (CDCl3) l 7.83–7.81 (m, 12H,
Ph), 7.39–7.34 (m, 18H, Ph), 6.26 (d, J 8.5, 4H, Ar),
6.10 (d, J 8.5, 4H, Ar), 3.42 (brs, 4H, NH2); 31P NMR
(CDCl3) 19.6 (t, JPtꢁP 2674); mass spectrum (FAB): m/z
952 (M+). Elemental analysis: Anal. Found: C, 64.80;
H, 4.27; N, 2.81. Calc. for PtP2C52H42N2, C, 65.62; H,
4.42; N, 2.94%.
and
the
residue
air-dried.
Extraction
with
dichloromethane (2×100 cm3) gave an orange solution
which was dried with MgSO4 and afforded 7 (0.07 g,
14%) as an orange–red solid upon removal of volatiles.
4.12. Synthesis of trans-[Pt(PnBu3)2(CꢀC-C6H4NH2)2]
(11)
IR (KBr) w(CꢀC) 2202, 2135 cm−1; H NMR (CDCl3)
This was prepared in an analogous fashion to 10
using 1 (0.32 g, 2.73 mmol) and [PtCl2(PnBu3)2] (0.83 g,
1.24 mmol) with stirring for 4 h. A viscous brown oil
resulted which was chromatographed on silica to give a
yellow band eluting with light petroleum–benzene (1:1).
Removal of volatiles gave 11 (0.80 g, 78%) as an orange
oil. IR (KBr) 3347 (NH), 3343 (NH), 2100 (CꢀC)
1
l 7.32 (d, J 8.6, 4H, Ar), 6.59 (d, J 8.6, 4H, Ar), 3.87
(brs, 4H, NH2); mass spectrum (EI): m/z 232 (M+).
4.10. Synthesis of 1,2,4- and
1,3,5-tris-(4-aminophenyl)benzene (8) and
1,4-bis(4-aminophenyl)buta-trans-1-en-2-yne (9)
1
cm−1; H NMR (CDCl3) l 7.09 (d, J 8.4, 4H, Ar), 6.56
[Ni(CO)2(PPh3)2] (0.043 g, 0.067 mmol) and 1 (0.50 g,
4.27 mmol) were placed in a two-necked round bottom
flask fitted with a water condenser and nitrogen by-pass
and purged thoroughly with nitrogen. Toluene (30 cm3)
was added and the resulting yellow solution was heated
to 80°C for 4 h. Removal of volatiles gave a dark
brown solid which was chromatographed on silica gel
with light petroleum. Elution with diethyl ether–light
petroleum (1:2) gave a yellow band which afforded 9
(0.17 g, 34%). IR (KBr) 3420 (NH), 3380 (NH), 2104
(d, J 8.4, 4H, Ar), 3.60 (brs, 4H, NH2), 2.18–2.15 (m,
12H, CH2), 1.42–1.46 (m,24H, CH2), 0.94–0.90 (m,
18H, Me); 31P NMR (CDCl3–CH2Cl2) 9.22 (t, JPtꢁP
2376); mass spectrum (FAB): m/z 831 (M+). Elemental
analysis: Anal. Found: C, 57.88; H, 7.99; N, 3.43. Calc.
for PtP2C40H66N2, C, 57.76; H, 7.94; N, 3.37%.
4.13. Synthesis of cis-[Pt(p2-dppe)(CꢀCC6H4NH2)2]
(12)
1
(CꢀC) 1650 (NH2) cm−1; H NMR (CDCl3) l 7.27 (d,
1 (0.56 g, 4.78 mmol) was placed into a three-necked
flask equipped with a condenser and bubbler. After
purging with nitrogen, diethyl ether (20 cm3) was added
to give a clear yellow solution. This was cooled in an
ice bath and butyllithium (1.2 ml, 2.99 mmol) was
added via syringe, resulting in formation of a yellow
solid and gas evolution. cis-[PtCl2(h2-dppe)] (0.20 g,
0.30 mmol) dissolved in thf (40 cm3) was added at
−78°C and after addition the solution was allowed to
warm slowly to room temperature and stirred for 48 h.
Aqueous NH4Cl (ca. 10 cm3) was added and the reac-
tion mixture transferred to a separating funnel. The top
orange layer was collected and washed with water,
dried with MgSO4 and pumped to dryness to yield 12
as a slightly sticky yellow solid. Dissolution in the
minimum amount of dichloromethane followed by ad-
dition of light petroleum gave a yellow precipitate
J 8.4, 2H, Ar), 7.23 (d, J 8.3, 2H, Ar), 6.89 (d, J 16.2,
1H, CꢂCH), 6.64 (d, J 8.2, 2H, Ar), 6.61 (d, J 8.3, 2H,
Ar), 6.17 (d, J 16.2, 1H, CꢂCH), 3.79 (brs, 4H, NH2);
mass spectrum (EI): m/z 234 (M+). Elution with
dichloromethane–acetone (4:1) gave broad orange
band which afforded 8a–b (0.15 g, 30%) as an oily
orange solid. IR (KBr) 3400 (NH), 3300 (NH), 1650
1
(NH2) cm−1; H NMR (CDCl3) l 7.70–6.70 (m, 15H,
Ar), 3.74–3.58 (br, 6H, NH2); mass spectrum (EI): m/z
351 (M+).
4.11. Synthesis of trans-[Pt(PPh3)2(CꢀC-C6H4NH2)2]
(10)
trans-[PtCl2(PPh3)2] (0.50 g, 0.63 mmol) and 1 (0.15
g, 1.28 mmol) were placed in a schlenk tube and

A.J. Deeming et al. / Inorganica Chimica Acta 309 (2000) 109–122
119
which was dried under vacuum to yield a dry yellow
powder (0.09 g, 36%). IR (KBr) 3424 (NH), 3332 (NH),
acetone (9:1) gave a second yellow band which afforded
103 mg of an orange–yellow solid as a mixture of
isomers and as yet not fully fully characterised. IR
(C6H14) w(CO) 2078s, 2049vs, 2016m, 2008s, 1995s,
1
2108 (CꢀC) cm−1; H NMR (CDCl3) l 8.00–6.97 (m,
20H, Ph), 6.61 (d, J 8.5, 4H, Ar), 6.46 (d, J 8.5, 4H,
Ar), 3.6 (br, 4H, NH2), 2.63–2.37 (m, 4H, CH2); 31P
NMR (CDCl3) 46.3 (t, JPtꢁP 2257); mass spectrum (EI):
m/z 826 (M+). Elemental analysis: Anal. Found: C,
60.90; H, 4.65; N, 3.46; P, 8.16. Calc. for
PtP2C42H36N2, C, 61.09; H, 4.36; N, 3.39; P, 7.52%.
1
1929m cm−1; H NMR (CDCl3) l 9.02 (s, NH, 0.6H),
8.88 (s, NH, 0.4H), 7.45–6.45 (m, 10H, Ph+CꢀCH),
3.92–3.70 (m); mass spectrum (FAB): m/z 606, 578,
550, 522, 494, 466, 438.
4.16. Synthesis of
4.14. Synthesis of all
trans-[Ru(CO)2(PEt3)2(CꢀCC6H4NH2)2] (13)
[(v-H)Ru3(CO)9(v3-CꢀCC6H4NH3)][X] (15)
Addition of a drop of HBF4·Et2O to a hexane solu-
tion of 14 resulted in a distinct lightening of the solu-
tion and complete loss of 14 as shown by IR. Similarly,
addition of CF3CO2H to a CDCl3 solution of 14 re-
sulted in rapid protonation as shown by 1H NMR
spectroscopy to give [(m-H)Ru3(CO)9(m3-CꢀCC6H4-
NH3)][X] (15). IR (C6H14) w(CO) 2134m, 2100s, 2075vs,
1 (0.38 g, 3.28 mmol) was placed into a three-necked
flask equipped with a condenser and bubbler. After
purging with nitrogen, diethyl ether (10 cm3) was added
to give a clear yellow solution. The solution was cooled
in an ice bath and butyllithium (2.2 ml, 5.48 mmol) was
added via syringe, resulting in formation of an orange
solution. All trans-[RuCl2(CO)2(PEt3)2] (0.76 g, 1.64
mmol) dissolved in thf (40 cm3) was added dropwise at
−78°C and after addition the yellow solution was
allowed to warm slowly to room temperature and
stirred for 18 h. The mixture was reduced to dryness to
give a slightly sticky orange solid. Chromatography on
silica eluting with dichloromethane–light petroleum
(1:1) gave an orange band which afforded 13 (ca. 25 g,
24%) as a slightly sticky orange solid. All attempts at
recrystallisation proved fruitless and thus we were un-
able to obtain satisfactory analytical data. IR (CH2Cl2)
2035 (CꢀC), 1972 (CO) cm−1; 1H NMR (CDCl3) l 7.06
(d, J 8.1, 4H, Ar), 6.51 (d, J 8.1, 4H, Ar), 3.55 (s, 4H,
NH2), 2.13–2.07 (m, 12H, CH2), 1.21 (quin, J 7.6, 18H,
CH3); 31P NMR (CDCl3) 24.3 (s).
1
2056s, 2026s, 1993sh cm−1; H NMR (CDCl3) l 7.58
(d, J 8.0, 2H, Ar), 7.18 (d, J 8.0, 2H, Ar), 6.20 (brs, 3H,
NH3), −6.47 (s, 1H, m-H).
4.17. Synthesis of Ph3PꢂNC6H4CꢀCH (16)
1 (1.00 g, 8.55 mmol) was dissolved in dry toluene (60
cm3) and dry NEt3 (4 cm3) was added via syringe. To
this was added slowly Ph3PBr2 (3.61 g, 8.55 mmol) in
toluene (40 cm3) to give a cloudy yellow solution which
was stirred for 18 h. The yellow precipitate formed was
removed by filtration and washed thoroughly with tolu-
ene and diethyl ether to afford 16 (3.22 g, 100%) as a
yellow flaky solid. IR (KBr) 2092w (CꢀC), 1596s,
1496vs, 1436s, 1327vs (P=N), 1259m, 1169m, 1104s,
1
1017m, 997m, 827m, 719s, 693s, 554m, 525s cm−1; H
4.15. Synthesis of [(v-H)Ru3(CO)9(v3-CꢀC6H4NH2)]
(14)
NMR (CDCl3) l 7.77–7.43 (m, 15H, Ph), 7.16 (d, J 8.6,
2H, Ar), 6.71 (d, J 8.6, 2H, Ar), 2.95 (s, 1H, CꢀCH);
31P NMR (CDCl3) 10.6 (s); mass spectrum (EI): m/z
377 (M+). Elemental analysis: Anal. Found: C, 82.59;
H, 5.38; N, 4.58. Calc. for PC26H20N, C, 82.76; H, 5.31;
N, 3.71%.
A heptane solution (30 cm3) of [Ru3(CO)12] (0.25 g,
0.39 mmol) and 1 (91 mg, 0.77 mmol) was heated at
95°C for 8 h resulting in the formation of an orange
solution and a yellow precipitate. After cooling to room
temperature, volatiles were removed under reduced
pressure to give a mustard solid. Chromatography on
silica eluting with hexane gave a yellow band which
afforded unreacted [Ru3(CO)12] (30 mg). Elution with
hexane–diethylether (3:2) gave a yellow band which
afforded 14 (73 mg, 32%). Crystals suitable for X-ray
crystallography were grown upon cooling a saturated
hexane solution to −20°C. IR (C6H14) w(CO) 2096w,
4.18. Attempted synthesis of
[Mo(NC6H4CꢀCH)Cl2(p2-S2CNEt2)2]
1 (0.20 g, 1.71 mmol) and [MoOCl2(h2-S2CNEt2)2]
(0.82 g, 1.71 mmol) were dissolved in dry methanol (50
cm3) and stirred for 16 h resulting in the formation of
a dark red solution. This was filtered and volatiles
removed under reduced pressure to afford a very sticky
red solid. This was washed with light petroleum and
dried to afford 16 (0.99 g, 86%) as a sticky red solid. IR
(KBr) 2098w (CꢀC), 1594w, 1526vs, 1457m, 1440m,
1380w, 1355m, 1277s, 1204m, 1150m, 1095m, 1075m,
1
2071s, 2053vs, 1989w cm−1; H NMR (CDCl3) l 7.39
(d, J 8.4, 2H, Ar), 6.64 (d, J 8.4, 2H, Ar), 3.89 (s, 2H,
NH2), −20.41 (s, 1H, m-H); mass spectrum (FAB): m/z
673 (M++1). Elemental analysis: Anal. Found: C,
29.71; H, 0.90; N, 1.95. Calc. for Ru3C17H7N1O9, C,
30.36; H, 1.04; N, 2.08%. Elution with diethylether–
1
945m, 847m cm−1; H NMR (acetone-d6) l 7.74 (d, J
8.8, Ar, a), 7.53 (d, J 8.7, Ar, b), 7.44 (d, J 8.7, Ar, b),

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A.J. Deeming et al. / Inorganica Chimica Acta 309 (2000) 109–122
6.68 (d, J 8.8, Ar, a), 4.05–3.87 (m, CH2), 2.57 (s,
ꢀCH, a), 2.40 (s, ꢀCH, b), 1.50–1.30 (m, CH3). The
ratio of peaks a:b was 3:5; mass spectrum (FAB): m/z
690 {Mo(h2-S2CNEt2)3(NC6H4C2H)+1}, 544. A mix-
ture of 16 (0.76 g, 2.00 mmol) and [MoOCl2(h2-
S2CNEt2)2] (0.64 g, 1.33 mmol) in toluene (50 cm3)
was refluxed for 24 h resulting in the formation of a
deep red solution. After filtration the volume was re-
duced to ca. 15 cm3 and light petroleum (ca. 20 cm3)
added which resulted in the precipitation of Ph3PꢂO.
This was filtered and volatiles removed under reduced
pressure to afford 16 (ca. 0.56 g) as a sticky red
solid. IR (KBr) 2094w (CꢀC), 1594w, 1520s, 1498vs,
1457m, 1437m, 1380w, 1341m, 1277s, 1204m, 1168m,
1150m, 1107s, 1074m, 998w, 837m cm−1; mass spec-
trum (FAB): m/z 657, 544, 509.
916, 718. Elemental analysis: Anal. Found: C, 64.94;
H, 4.18; N, 2.63; Cl, 2.09. 11 (0.30 g, 0.36 mmol) was
dissolved in dichloromethane (50 cm3) and to this was
added NEt3 (0.1 cm3) and terephthaloyl chloride (0.07
g, 0.34 mmol). The mixture was stirred at room tem-
perature for 24 h resulting in the deposition of a
yellow ppt. After filtration the yellow solid 19 was
washed thoroughly with water and light petroleum to
give as a yellow powder (0.33 g, 95%). 31P NMR
(DMF/CDCl3) 4.02 (t, JPtꢁP 2361 Hz); Mass spectrum
(FAB): m/z 1469, 984, 893, 597; mass spectrum
(TOFSPEC): m/z 2041, 1832, 1718, 1443, 1340, 1233,
1134, 1016, 902. Elemental analysis: Anal. Found: C,
58.56; H, 7.00; N, 3.23; Cl, 1.86%.
4.21. Synthesis of
4.19. Synthesis of
trans-[Pt(PPh3)2{CꢀCC6H4NHC(O)Ph}2] (17)
trans-[Pt(PPh3)2(CꢀCC6H4NꢂC6H10)2] (20)
Toluene (20 cm3) was added to a mixture of 10
(0.10 g, 0.11 mmol) and MgSO4 (ca. 0.1 g) and cyclo-
hexanone (0.06 ml, 0.63 mmol) was added via sy-
ringe. The solution was stirred at room temperature
for 18 h to give a yellow–orange solution. This was
filtered and volatiles were removed under reduced
pressure to give 20 (0.10 g, 86%) as an orange–brown
solid. All attempts to recrystallise this were unsuccess-
ful. IR (KBr) 2950w (CH), 2104w (CꢀC), 1702m
(CꢂN), 1619m (CꢂN), 1603m (CꢂN), 1510s, 1481m,
1430m, 1261s, 1096vs, 1018s, 802s, 750m, 710m, 694s,
10 (0.10 g, 0.11 mmol) was dissolved in
dichloromethane (70 cm3) and to this NEt3 (0.03 ml,
0.21 mmol) and benzoyl chloride (0.03 ml) were
added sequentially by syringe. The mixture was
stirred at room temperature for 18 h. Volatiles were
removed under reduced pressure to afford a sticky
brown solid. This was redissolved in dichloromethane
and washed thoroughly with water and finally dried
with MgSO4. Removal of volatiles gave 17 (0.11 g,
92%) as a brown solid. IR (KBr) 3560vs (NH),
3480vs (NH), 3416vs (NH), 2105w (CꢀC), 1640s
(CꢂO), 1618s (CꢂO), 1506s, 1481m, 1433m, 1392w,
1310w, 1261s, 1096vs, 1020s, 802s, 690s, 669m, 524m
1
525m cm−1; H NMR (CDCl3) l 7.82–7.15 (m, 30H,
Ph), 6.25 (d, J 8.6, 4H, Ar), 6.09 (d, J 8.6, 4H, Ar),
2.36 (m, 8H, CH2), 1.88 (m, 8H, CH2), 1.72 (m, 4H,
CH2); 31P NMR (CDCl3) 29.2 (t, JPtꢁP 2689, 20%),
26.4 (t, JPtꢁP 2686, 80%); mass spectrum (FAB): m/z
1112 (M++1).
1
cm−1; H NMR (CDCl3) l 8.10 (d, J 8.5, 4H, Ar),
7.90–7.29 (m, 40H, Ph), 6.15 (d, J 8.5, 4H, Ar); 31P
NMR (CDCl3) 28.2 (t, JPtꢁP 2651), 27.7 (t, JPtꢁP
3000); mass spectrum (FAB): m/z 1160 (M+). Ele-
mental analysis: Anal. Found: C, 62.89; H, 4.45; N,
1.73. Calc. for PtP2N2O2C66H50·1.5CH2Cl2, C, 62.91;
H, 4.12; N, 2.17%.
4.22. Synthesis of
trans-[Pt(PPh3)2(CꢀCC6H4NꢂCHꢁFc)2] (21)
4.20. Synthesis of oligomers 18–19
Ferrocenecarboxaldehyde (0.08 g, 3.58 mmol),
MgSO4 (0.09 g) and 10 (0.17 g, 0.18 mmol) were
dissolved in toluene (50 cm3) and refluxed for 60 h.
The red solution was filtered and volatiles removed
under vacuum. Sublimation at 30–40°C resulted in
removal of unreacted ferrocenecarboxaldehyde. The
remaining red solid was washed thoroughly with di-
ethyl ether to afford 21 (0.10 g, 63%) as a dry red
solid. IR (KBr) 2964m (CH), 2102w (CꢀC), 1638s
10 (0.17 g, 0.18 mmol) was dissolved in
dichloromethane (40 cm3) and to this was added
NEt3 (0.1 cm3) and terephthaloyl chloride (0.04 g,
0.18 mmol). The mixture was stirred at room temper-
ature for 60 h resulting in the deposition of a fine
yellow ppt. After filtration the yellow solid was
washed thoroughly with water to remove salts and
dried to afford 18 (0.13 g, 65%) as a fine yellow
powder. IR (KBr) 3050w (NH), 2106m (CꢀC), 1696w
(CꢂO), 1667m (CꢂO), 1587m, 1520m, 1506s, 1483m,
1435m, 1315m, 1099m, 835w, 740w, 700w, 693s, 520s
cm−1; mass spectrum (FAB): m/z 919, 764, 720, 613;
mass spectrum (TOFSPEC): m/z 1101, 1050, 984,
(CꢂN), 1627s (CꢂN), 1607s (CꢂN) cm−1 1H NMR
;
(CDCl3) l 8.22 (s, 2H, CHꢂN), 7.83 (m, 12H, Ph),
7.39 (m, 18H, Ph), 6.75 (d, J 8.2, 4H, Ar), 6.29 (d, J
8.2, 4H, Ar), 4.75 (s, 4H, C5H4), 4.46 (s, 4H, C5H4),
4.22 (s, 10H, C5H5); 31P NMR (CDCl3) 21.9 (t, JPtꢁP
2707); mass spectrum (FAB): m/z 1344 (M+).

A.J. Deeming et al. / Inorganica Chimica Acta 309 (2000) 109–122
121
4.23. Synthesis of trans-[Pt(PPh3)2-
(CꢀC6H4C6H4NꢂPPh3)2] (22)
detector diffractometer using graphite monochromated
Mo Ka radiation. For 1 and 14 the lattice vectors were
identified by application of the automatic indexing rou-
tine of the diffractometer to the positions of a number
of reflections taken from a rotation photograph and
centred by the diffractometer. The ꢀ–2q technique was
used to measure reflections in the range 552q550°
and three standard reflections (remeasured every 97
scans) showed no significant loss in intensity during
data collection. The data were corrected for Lorentz
and polarisation effects, and empirically for absorption.
For 10 a full hemisphere of reciprocal space was
scanned by 0.3° ꢀ steps and a SADABS absorption
correction was made. The unique data with I]2.0|(I)
were used to solve and refine the structures. Non-hy-
drogen atoms were refined anisotropically. Hydrogen
atoms in 14 were placed in idealised positions (CꢁH
10 (0.30 g, 0.32 mmol) was dissolved in toluene (70
cm3) and Ph3PBr2 (0.27 g, 0.63 mmol) and Et3N (0.32 g,
3.25 mmol) were added sequentially. The mixture was
refluxed for 18 h resulting in a gradual colour change
from yellow to orange and formation of a fine orange
precipitate. Upon cooling to room temperature this was
filtered and washed thoroughly with diethyl ether to
give 22 (0.30 g, 65%) as a fine orange solid. Recrystalli-
sation from dichloromethane–light petroleum gave yel-
low needles. IR (KBr) 2104w (CꢀC), 1595m, 1496s,
1482m, 1435s, 1400w, 1352m (PꢂN), 1335m (PꢂN),
1261m, 1173w, 1162m, 1101vs, 1035s, 802s, 720m, 692s,
1
548m, 528m, 525m cm−1; H NMR (CDCl3) l 7.80–
7.28 (m, 60H, Ph), 6.36 (d, J 8.0, 4H, Ar), 5.97 (d, J
8.0, 4H, Ar); 31P NMR (CDCl3–CH2Cl2) 26.3 (t, JPtꢁP
2705), 7.3 (s, PꢂN); mass spectrum (FAB): m/z 1473
(M++2). Elemental analysis: Anal. Found: C, 68.73;
H, 4.50; N, 1.70. Calc. for PtP4N2C88H68·CH2Cl2, C,
68.64; H, 4.24; N, 1.80%.
,
0.96 A) and assigned a common isotropic thermal
2
,
parameter (U=0.08 A ) while those of 1 and 10 were
located from difference maps and refined isotropically.
Selected crystallographic details are summarised in
Table 1.
4.24. Crystallographic data
Acknowledgements
Suitable single crystals were mounted in air onto
glass fibres, 10 being mounted using grease. Data col-
lections for 1 and 14 were performed at room tempera-
ture on a Nicolet R3 mV automated four-circle
diffractometer equipped with a Mo Ka radiation source
or for 10 at 173 K on a Siemens (Bruker) SMART area
We thank the EPSRC for partial funding of this
work and studentships to M.-Y.L. and S.P.R. and
Professor Peter J. Garratt for his help in the early
stages of the project.
Table 1
Selected crystallographic details for complexes 1, 10 a and 14
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1
10
14
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formula
C8H7N
C62H50.33C11·64
N2P2Pt
1138.50
hexagonal
R3
26.313(2)
26.313(3)
19.609(2)
90
90
120
11758(2)
9
2.872
-
C17H7NO9Ru3
Formula weight 117.15
Crystal system orthorhombic
672.45
monoclinic
P21/c
8.7073(5)
12.745(5)
19.288(7)
90
90.51(4)
90
2139(2)
4
Space group
Pman
7.0734(14)
9.037(2)
10.335(3)
90
90
90
660.7(3)
4
0.07
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4016
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Independent
reflections
Rint
3007
25172
821
6003
3761
0.0477
0.140
0.0266
0.0259
0.0339
0.0294
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