Some cyclic ligands obtained from reactions of polycyanocarbon-metal complexes Dedicated to our friend and colleague Claude Lapinte on his 65th birthday, in recognition of his extensive contributions to organo-iron chemistry.

Article abstract of DOI:10.1016/j.jorganchem.2013.12.038

Several complexes containing Ru(dppe)Cp* fragments attached to heterocyclic ligands were obtained from polycyanocarbons. Reactions of Ru{CCC(CN)C(CN)₂}(dppe)Cp* with LiCCSiMe₃ and LiOCHCH₂ gave binuclear {[Ru(dppe)Cp*]CC-c-CC(CCSiMe ₃)N(Ha?OH₂)CCC(CN)}₂(NN) 2 and Ru{c-CCHC[C(CN)₂]CHCHO}(dppe)Cp* 4 [together with known Ru{CCCMeC(CN)₂}(dppe)Cp* 3], respectively, while lithiation of Ru(CCCCH)(dppe)Cp* and subsequent reaction with TCNE afforded Ru{CC-c-CC(CN)C(O)NH[C(CN)₂]}(dppe)Cp* 6 and Ru{CC-c-CCHC[C(CN)₂]NHCMeN}(dppe)Cp* 7, as well as known {Ru(dppe)Cp*}₂{μ-CCC[C(CN)₂]C[C(CN) ₂]CC} 5. A second product from the earlier described reaction between TCNE and Ru(CCCCI)(dppe)Cp* was identified as Ru{CC-c-CC(CN)C(CN) C(NH₂)C(CN)₂}(dppe)Cp* 9. X-ray determined structures of 2, 4, 6, 7 and 9 are reported together with plausible routes by which they may be formed.

Full text of DOI:10.1016/j.jorganchem.2013.12.038

Journal of Organometallic Chemistry 756 (2014) 68e78
Contents lists available at ScienceDirect
Journal of Organometallic Chemistry
journal homepage: www.elsevier.com/locate/jorganchem
Some cyclic ligands obtained from reactions of polycyanocarbone
metal complexes
,
a
a
a,b
Michael I. Bruce a , Alexandre Burgun , Martyn Jevric , Jonathan C. Morris
,
*
Brian K. Nicholson c, Christian R. Parker a, Nancy Scoleri a, Brian W. Skelton d
,
,
1
Natasha N. Zaitseva a
a School of Chemistry & Physics, University of Adelaide, Adelaide, South Australia 5005, Australia
b School of Chemistry, University of New South Wales, Kensington, NSW 2052, Australia
c Department of Chemistry, University of Waikato, Hamilton, New Zealand
d Chemistry M313, School of Biomedical, Biomolecular and Chemical Sciences, University of Western Australia, Crawley, Western Australia 6009, Australia
a r t i c l e i n f o
a b s t r a c t
Article history:
Several complexes containing Ru(dppe)Cp* fragments attached to heterocyclic ligands were
obtained from polycyanocarbons. Reactions of Ru{C^CC(CN)]C(CN)2}(dppe)Cp* with LiC^CSiMe3 and
LiOCH]CH2 gave binuclear {[Ru(dppe)Cp*]C^Cec-C]C(C^CSiMe3)N(H/OH2)CC]C(CN)}2(N]N) 2
and Ru{c-C]CHC[]C(CN)2]CH]CHO}(dppe)Cp* 4 [together with known Ru{C^CCMe]C(CN)2}(dppe)
Cp* 3], respectively, while lithiation of Ru(C^CC^CH)(dppe)Cp* and subsequent reaction with TCNE
Received 11 October 2013
Received in revised form
20 December 2013
Accepted 21 December 2013
afforded Ru{C^Cec-C]C(CN)C(O)NH[]C(CN)2]}(dppe)Cp*
NHCMe]N}(dppe)Cp* 7, as well as known {Ru(dppe)Cp*}2{
second product from the earlier described reaction between TCNE and Ru(C^CC^CI)(dppe)Cp* was
identified as Ru{C^Cec-CC(CN)C(CN)]C(NH2)C(CN)2}(dppe)Cp* 9. X-ray determined structures of 2, 4,
6, 7 and 9 are reported together with plausible routes by which they may be formed.
Ó 2014 Elsevier B.V. All rights reserved.
6
and Ru{C^Cec-C]CHC[]C(CN)2]
Dedicated to our friend and colleague
Claude Lapinte on his 65th birthday, in
recognition of his extensive contributions to
organo-iron chemistry.
m
-C^CC[]C(CN)2]C[]C(CN)2]C^C} 5. A
Keywords:
Ruthenium
Cyanocarbon
Crystal structure
Ligand reactivity
1. Introduction
An interesting structural feature of structure E is the presence of a
short RueC bond, consistent with some degree of multiple bonding
The reactions of tetracyanoethene [(NC)2C]C(CN)2, TCNE] with
alkynyl- and poly-ynyl-transition metal complexes have been
studied for many years [1]. Characteristic of these is cycloaddition
to an alkynylemetal complex to give a zwitterionic intermediate B
(possibly formed from an initially formed radical cationeanion salt
[{LnM}eCCeR]þꢀ[TCNE]ꢁꢀ A), which rapidly evolves via a [2 þ 2]-
cycloaddition reaction to the tetracyanocyclobutenyl derivative C,
which in turn undergoes a more or less ready ring-opening (retro-
character. This feature has been examined in more detail using DFT
calculations [2].
An alternative reaction path which has been detailed recently
involves the reactions of strongly nucleophilic ethynyl-metal
complexes, such as Ru(C^CH)(dppe)Cp*, which react with TCNE
to give tricyanovinylethynyl complexes F by substitution of one CN
group of the TCNE molecule (Scheme 1) [3]. The CN group in F that
is gem to the MLn group is readily displaced by other nucleophiles,
while addition of other M0L0m fragments to the CN group trans to
MLn can also occur. Protonation of the C^C triple bond affords a
vinylidene derivative which is easily deprotonated.
In the chemistry of TCNE itself, formation of cyclic systems oc-
curs readily, either by double displacement of CN groups, e.g., with
ethylene glycol, or by attack on one or more of the CN groups
themselves [4]. Much of this chemistry was uncovered during the
early comprehensive studies of the reactions of TCNE and has been
reviewed [5,6]. More fundamental have been the studies of
cycloaddition) to form a
h
1-tetracyanobuta-1,3-dienyl complex D
(Scheme 1). A further reaction occurs if a weakly bound 2-e donor
ligand is present on the metal centre, which can be displaced with
formation of the analogous
h
3-tetracyanobutadienyl complexes E.
* Corresponding author. Fax: þ61 8 8303 4358.
E-mail address: michael.bruce@adelaide.edu.au (M.I. Bruce).
Current address: Centre for Microscopy, Characterisation and Analysis M313,
1
hydrogen cyanide, which is
a potent source of heterocyclic
University of Western Australia, Crawley, Western Australia 6009, Australia.
0022-328X/$ e see front matter Ó 2014 Elsevier B.V. All rights reserved.
http://dx.doi.org/10.1016/j.jorganchem.2013.12.038

M.I. Bruce et al. / Journal of Organometallic Chemistry 756 (2014) 68e78
69
[LnM+]
R
R
[LnM]
NC
C
C
C
[LnM]
NC
C
C
C
C
R
C
CN
CN
NC
CN
C
C
C
C
CN
NC
NC
CN
NC
CN
A
B
CN
C
NC
C
NC
CN
[LnM]
NC
R
NC
C
C
CN
+ L
- L
[LnM]
C
C
R
C
R
[Ln-1M]
[LnM]
CN
C
C
CN
CN
C
F
NC
CN
NC
NC
CN
D
E
C
Scheme 1. [2 þ 2]-Cycloaddition of TCNE to alkynylemetal complexes. For F, [MLn] ¼ Ru(PPh3)2Cp, Os(PPh3)2Cp, Ru(dppe)Cp*.
HN
HN
OR
{Ln-1M}
{LnM}
CN
CN
{LnM}
C
OR
ROH
R = H, Me, Et
X
CN
X
X
CN
G
LnM = Mo(CO)3Cp, X = Cl, CN; LnM = W(CO)3Cp, X = CFc=C(CN)2
Scheme 2. Hydrolysis of tricyanovinyl ligands to imido chelates.
compounds [7]. This topic has also been surveyed by Donald and
Webster [8], who have emphasised the chemistry of HCN trimers,
including aminomalononitrile, diaminomaleonitrile (DAMN) and
the oxidation product of the latter, diiminosuccinonitrile (DISN).
Conversions of DAMN to imidazoles or pyrazines predominate,
while several other N-heterocyclic systems can be obtained from
HCN.
In the course of further studies of the chemistry of TCNE with
alkynylemetal complexes and related compounds, we have
discovered several products which contain new cyclic ligands. X-
ray structural studies of some of these complexes and plausible
routes by which they may be formed form the subject of this
account.
However, reports of further transformations of polycyanocarbon
ligands in their metal complexes are relatively rare. Ready hydrolysis
or alcoholysis of a CN group may afford chelate imido complexes G,
such as Mo{NH]C(OR)CX]C(CN)}(CO)2Cp (R ¼ H, Me, Et), from Mo
{CX]C(CN)2}(CO)3Cp (X ¼ Cl, CN) with ROH, or W{NH]C(OMe)
2. Results and discussion
2.1. Reactions of Ru{C^CC(CN)]C(CN)2}(dppe)Cp*
2.1.1. With LiC^CSiMe3
C(CN)]CCFc]C(CN)2}(CO)2Cp, from W{h
1-C[]C(CN)2]CFc]C(C
As mentioned above, reactions of the tricyanovinyl complex Ru
N)2}(CO)3Cp and MeOH (Scheme 2) [9,10].
{C^CC(CN)]C(CN)2}(dppe)Cp*
1 with nucleophiles, such as
Nu ¼ Hꢁ, Rꢁ, ORꢁ, NR2ꢁ or PRꢁ2 , result in displacement of a second CN
group, gem to the metal centre, to give Ru{C^CCNu]C(CN)2}(dppe)
Cp* 3 [3]. In extending these reactions to unsaturated carbon nu-
cleophiles, we have examined the reactions between 1 and several
lithiated alkynes. Most of these have given unresolved mixtures of
products, there being so far only one well-characterised replace-
ment of CN by an alkynyl group, namely from the reaction with
Ru(C^CC^CLi)(dppe)Cp*, which afforded the binuclear complex
More recently, we described cycloaddition of azide to a CN
group of the tetracyanobutadienyl ligand in E to give bicyclic sys-
tems such as Ru{C[CPh]C(CN)2]]C(CN)CN4}(PPh3)Cp H (Scheme
3) [2].
(NC)2C
[Ru]
Ph
(NC)2C
CN
N
Ph
{Cp*(dppe)Ru}{m-C^CC[]C(CN)2]C^CC^C}{Ru(dppe)Cp*} [11]. In
NaN3
contrast, the related reaction with LiC^CSiMe3 at room
temperature afforded as the major product the dark green sym-
metrical azo dimer {[Ru(dppe)Cp*]C^Cec-C]C(C^CSiMe3)
N(H/OH2)C(N]. )](CN)}2 2 (Chart 1) which was identified by a
single-crystal X-ray diffraction study. Chart 1 illustrates the struc-
tures of complexes whose structures have been determined crys-
tallographically during this work.
[Ru]
N
N
NC
CN
N
E
[Ru] = Ru(PPh3)Cp
H
Fig. 1 is a plot of a centrosymmetric binuclear molecule of 2;
selected bond parameters of all structures described herein are
Scheme 3. Cycloaddition of azide to an h
3-tetracyanobutadienyleruthenium complex.

70
M.I. Bruce et al. / Journal of Organometallic Chemistry 756 (2014) 68e78
SiMe3
30 / 31,32
C(CN)2
42
C
2
Ru
1
Ru
PPh2
1
C
Ph2P
Ph2P
41
C
4
3
PPh2
2
6
C
O
4
3
5
5
N
H
OH2
7
71
NC
6
4
6
N
2
2
Ru
PPh2
Ru
PPh2
40 / 41,42
C(CN)2
1
C
1
C
Ph2P
Ph2P
50 / 51,52
C(CN)2
2
4
2
C
C
3
3
4
5
NH
5
8
7
6
6
N
NH
7
NC
71
6
O
Me
71
6
7
Ru
PPh2
1
C
40 / 41,42
C(CN)2
Ph2P
2
C
3
7
4
51
5
CN
71
NC
6
NH2
6
9
Chart 1. Partial atom-numbering schemes for organic ligands in complexes 2, 4, 6, 7 and 9, whose crystallographically-determined structures are reported herein.
included in the respective Figure captions. The familiar Cp*(dppe)
RueC^Ce moiety is present in all molecules which have been
structurally characterised in this work. In the five structures
described below, the near octahedral Ru(dppe)Cp* fragment is
characterised by normal bond parameters for RueP(1,2) [2.262e
Spectroscopic data for 2 are in accord with the solid-state
structure. The IR spectrum contains
n
(CN) (2218 cmꢁ1),
n
(C^C)
(C]C)
[2050 with 1971 (sh) cmꢁ1], (N]N) (1464 cmꢁ1) and
n
n
bands (1421 and 1377 cmꢁ1). The 1H and 13C NMR spectra contain
the expected signals for the metaleligand fragment, together with
resonances at dH 0.23, dC 0.44 for the SiMe3 groups. The ES-MS
contained [M þ H]þ at m/z 1718 and [Ru(dppe)Cp*]þ at m/z 635;
while no elemental microanalyses have been obtained (the com-
pound is relatively unstable and rapidly turns brown), the dimeric
formulation is confirmed by HR-MS on [M þ H]þ (found m/z
1718.344, calcd 1718.442). However, the water molecule attached to
NH(5) could not be detected in the mass spectrum.
ꢀ
ꢀ
2.302(2) A] and RueC(cp) [2.248e2.271 A], with P(1)eRueP(2)
[81.66e84.10(4)ꢂ] and P(1,2)eRueC(1) [81.6e92.65(7)ꢂ]. For 2, this
ꢀ
group has Ru(1)eC(1) and C(1)eC(2) 1.996(5) and 1.198(7) A,
ꢀ
respectively, cf. similar values for RueC 2.025(2), C^C 1.202(3) A in
1 [3]. It is attached by C(2) to atom C(3) of a pyrrole ring (crystal-
lographic numbering). The heterocycle also carries trimethylsily-
lethynyl [at C(4)] and cyano [at C(7)] substituents. Short separations
ꢀ
between atoms C(3)eC(4) and C(6)eC(7) [1.403(7), 1.395(7) A,
A plausible mechanism for this unusual reaction is given in
Scheme 4. Attack by LiC^CSiMe3 at the CN attached to C(3) of 1,
followed by intramolecular attack at the cis CN on C(4) gives the
anion {Cp*(dppe)Ru}{c-C]C(CN)C(]Nꢁ) N]C(C^CSiMe3)} I.
Protonation of I (from either an excess of HC^CSiMe3 or THF
respectively] are consistent with localised C]C double bonds. The
pyrrole NH group is hydrogen-bonded to a water molecule [N(5)e
ꢀ
H/O(1) 2.845(8) A], and two pyrrole nuclei are joined through an
0
ꢀ
azo group [N(6)]N(6 ), 1.303(8) A] at C(6).

M.I. Bruce et al. / Journal of Organometallic Chemistry 756 (2014) 68e78
71
NC
solvent) forms the diazafulvene J, which would be a potent elec-
NC
C
N
C
trophile. A significant driving force may be the formation of the
aromatic pyrrole in J. Addition of a further equiv. of anion I at N(5)
of the imine and subsequent tautomerisation would generate the
diazo compound. Subsequent protonation (either from its sur-
roundings or upon work-up) gives 2.
C
C
N
C
C
C
C
[Ru*]
[Ru*]
C
C
N
C
C
N
C
1
Me3Si
C
H+
Me3Si
I
[Ru*]
2.1.2. With LiOCH]CH2 (a decomposition product formed by
reaction between LiBu and THF)
C
H
Me3Si
C
NC
C
N
C
While the reaction of LiC^CC^CLi, formed by double desilyla-
tion of Me3SiC^CC^CSiMe3 with LiBu in THF, with 1 does not
proceed at ꢁ78 ꢂC, two major products were isolated from a reac-
tion carried out at room temperature. These were identified as the
known orange Ru{C^CCMe]C(CN)2}(dppe)Cp* 3 (R ¼ Me)3 (24%)
and yellow Ru{c-C]CHC[]C(CN)2]CH]CHO}(dppe)Cp* 4 (17%).
The same products were also formed in the absence of
Me3SiC^CC^CSiMe3, suggesting that it was LiOCH]CH2 (formed
by elimination of ethene from THF in the presence of LiBu [12e14])
which reacted with 1. The structures of both compounds were
determined by single-crystal X-ray diffraction studies, that of 3
matching the previously determined structure [3c]. The formation
of the methyl adduct 3 (R ¼ Me) was initially surprising as LiBu
rather than LiMe was used for desilylation Me3SiC^CC^CSiMe3.
However, all the experimental data confirmed the identity as 3
(R ¼ Me) rather than the n-butyl analogue 3 (R ¼ Bu) [3].
The molecule of 4 (Fig. 2) contains a 4-(dicyanomethylene)py-
ran-2-yl ligand coordinated to the Ru(dppe)Cp* fragment via the
C
C
C
C
C
CN
C
C
C
[Ru*]
N
+ H+
N
C
C
N
C
NC
C
N
C
N
C
C
H
C
Me3Si
NC
C
C
C
[Ru*]
C
N
NH
J
C
base
C
C
C
C
C
C
C
[Ru*]
SiMe3
Me3Si
I
SiMe3
C
CN
[Ru*]
C
C
N
C
C
C
N
N
C
C
C
C
C
C
C
C
N
C
[Ru*]
NC
H
H+
C
Me3Si
HN
ꢀ
RueC(1) bond [2.038(2) A]. Within the planar six-membered ring,
SiMe3
ꢀ
ꢀ
Ph2P
Ru
C
short C(1)eC(2) [1.387(3) A] and C(4)eC(5) [1.328(3) A] separations
confirm the locations of C]C double bonds; the exocyclic C(3)e
PPh2
1
CN
C
2
C
C
7
6
C
3
C
C
ꢀ
6
6'
C(30) bond [1.401(3) A] is similar to the first of these. The differing
N
C
C
C
C
N
ꢀ
ꢀ
bonds from O(6) to C(1) [1.396(3) A] and to C(5) [1.347(3) A] suggest
that there is a degree of electron delocalisation onto the C(4)e
C(5)eO(6) fragment, perhaps indicating a degree of charge sepa-
ration (zwitter-ion). However, the normal RueC(1) bond length
C
C
NH
5
41
C
4
C
Ru
NC
42
Ph2P
C
PPh2
Me3Si
2
Scheme 4. A plausible mechanism for the formation of {[Ru(dppe)Cp*]C^Cec-C]C(
C^CSiMe3)N(H/OH2)C(N]. )](CN)}2 2. [Ru*] ¼ Ru(dppe)Cp*.
ꢀ
[2.038(1) A] indicates that there is no significant charge donation
from the Ru centre.
Spectroscopic data of 4 are generally in accord with its solid-
state structure, with the exception of the unusually downfield
singlet in the 31P NMR at dp 93.6 [which may be compared to the
usual value for Ru(C^CR)(dppe)Cp* of dp ca 80]. This feature may
indicate a partial zwitter-ionic structure for 4, with some positive
charge on the metal centre (see three resonance structures shown).
The IR spectrum has
n
(CN) [2194, 2170 cmꢁ1] and
n(C]C) bands
[1620, 1476, 1453, 1436 cmꢁ1], but no
n
(C^C) absorption. The 1H
NMR spectrum shows three ]CH resonances at dH 5.85(dd), 6.33(d)
and 6.54(s, br). The 13C NMR spectrum contains two CN singlets [dC
119.17, 119.63] with other carbons of the heterocyclic ring at dC
107.94, 124.19, 148.70 and 153.53. A peak at dC 217.04, broadened by
coupling to phosphorus, is assigned to RueC. The dppe singlet in
the 31P NMR spectrum is at
usual value for dP at ca 80 usually found for Ru(C^CR)(dppe)Cp*
complexes. The ES-MS contained Mþ and [Ru(dppe)Cp*]þ at m/z
778 and 635, respectively.
Possible routes for the formation of 3 and 4 (Scheme 5) involve
deprotonation (metallation) of solvent THF with the organolithium
reagent, which is a well-known reaction pathway, often occurring
to the detriment of intended syntheses run in this solvent [12e14].
Ether cleavage, following deprotonation at Ca to give either
LiOCH2CH2CH]CH2 [15], or ethene and LiOCH]CH2 (the lithiated
d 93.6, somewhat downfield from the
Fig. 1. Plot of
a molecule of {[Ru(dppe)Cp*]C^Cec-C]C(C^CSiMe3)N(H/OH2)
C(N]. )](CN)}2 2. One component of the disordered atoms and hydrogen atoms
[except those on N(5,50)] have been omitted. Selected bond parameters: RueC(1)
1.996(5), C(1)eC(2) 1.198(7), C(2)eC(3) 1.428(7), C(3)eC(4) 1.403(7), C(3)eC(7)
1.424(7), C(4)eN(5) 1.374(6), C(4)eC(41) 1.408(7), C(41)eC(42) 1.206(7), C(42)eSi(4)
1.845(5), N(5)eC(6) 1.353(6), C(6)eN(6) 1.369(7), C(6)eC(7) 1.395(7), N(6)eN(60)
ꢀ
1.303(8) A. RueC(1)eC(2) 177.3(4), C(1)eC(2)eC(3) 164.3(5), C(2)eC(3)eC(4) 126.4(5),
C(2)eC(3)eC(7) 127.0(5), C(3)eC(4)eN(5) 108.1(4), C(3)eC(4)eC(41) 130.1(5), C(4)e
N(5)eC(6) 110.1(4), N(5)eC(6)eC(7) 108.2(4), N(5)eC(6)eN(6) 126.6(5), N(6)eC(6)e
C(7) 125.0(5), C(3)eC(7)eC(6) 107.5(4), C(6)eN(6)eN(60) 112.0(5), C(4)eC(41)eC(42)
175.7(6), C(41)eC(42)eSi(4) 174.2(5)ꢂ.

72
M.I. Bruce et al. / Journal of Organometallic Chemistry 756 (2014) 68e78
C(CN)2]C^C} 5 was isolated as the major product in 32% yield [19].
This compound was characterised by the usual spectroscopic
methods (specifically, IR
(CN) bands at 2208 and 2075 cmꢁ1, an AB
n
quartet in the 31P NMR spectrum at
d 81.3, 79.9 [both d,
3J(PP) ¼ 13 Hz] and [M þ Na]þ at m/z 1493 in the ES-MS of a solution
in MeOH containing NaOMe).
Two other compounds were isolated from this reaction: blue Ru
{C^Cec-C]C(CN)C(O)NHC[]C(CN)2]}(dppe)Cp*
6
(20%) and
bright orange Ru{C^Cec-C]CHC[]C(CN)2]NHCMe]N}(dppe)Cp*
7 (16%). Single crystals of both complexes suitable for X-ray studies
were grown from CH2Cl2/hexane and Figs. 3 and 4 show molecular
projections of 6 and 7, respectively. Elemental microanalyses are in
accord with the solid-state structure of 6, while high resolution MS
measurements confirm [M þ Na]þ for 6, and [M ꢁ Me]þ for 7.
In 6, the organic ligand is a substituted methyleneepyrrolone
ꢀ
attached to the metal centre by an RueC(1) single bond [1.964(11) A].
ꢀ
The C(1)eC(2) separation of 1.22(1) A and angles RueC(1)eC(2) and
C(1)eC(2)eC(3), both close to linear at 175.2(8) and 166.9(12)ꢂ,
respectively, are consistent with the presence of a C^C triple bond
between atoms C(1) and C(2). Atom C(2) is attached to the cyclic C4N
ꢀ
portion of the ligand by a CeC single bond [C(2)eC(3) 1.43(2) A],
Fig. 2. Plot of
a molecule Ru{c-C]CHC[]C(CN)2]CH]CHO}(dppe)Cp* 4. Some
with atoms C(3)eC(4)eN(5)eC(6)eC(7) forming part of a cyano(di-
cyanomethylene)pyrrolone heterocycle, with double bonds located
between atoms C(4)eC(40), C(3)eC(7) [1.38(2), 1.43(2) A] and C(6)e
O(6) [1.26(2) A]. Some charge delocalisation is suggested by sepa-
rations between atoms C(4)eN(5) [1.32(1) A] and C(7)eC(71)
[1.34(2) A], which are both significantly shorter than single bonds.
hydrogen atoms have been omitted for clarity. Selected bond parameters: RueC(1)
2.038(2), C(1)eC(2) 1.387(3), C(1)eO(6) 1.396(3), C(2)eC(3) 1.416(3), C(3)eC(4)
1.429(3), C(3)eC(30) 1.401(3), C(30)eC(31,32) 1.419, 1.422(4), C(4)eC(5) 1.328(3),
ꢀ
ꢀ
ꢀ
C(5)eO(6) 1.347(3) A. RueC(1)eC(2) 126.2(2), RueC(1)eO(6) 118.9(2), C(2)eC(1)eO(6)
114.9(2), C(1)eC(2)eC(3) 124.9(2), C(1)eO(6)eC(5) 121.3(2), C(2)eC(3)eC(4) 115.5(2),
C(2)eC(3)eC(30) 122.9(2), C(3)eC(4)eC(5) 118.9(2), C(4)eC(5)eO(6) 124.5(2), C(4)e
C(3)eC(30) 121.6(2)ꢂ.
ꢀ
ꢀ
Internal angles in the C4N ring range between 106 and 110(1)ꢂ.
enol of MeCHO) [16], followed by retro-[3 þ 2]-cycloaddition, are
the commonly observed routes. In some instances, the O-nucleo-
phile may ketonise to the C-nucleophile, LiCH2CHO, which is more
reactive and hence less stable.
Here, attack of LiCH2CHO (alkyllithiums are more reactive than
alkoxides with 1 [3]) on 1 produces an intermediate aldehyde Ru
{C^CC(CH2CHO)]C(CN)2}(dppe)Cp* K which then reacts further
to give the two reaction products 3 (R ¼ Me) and 4, as shown.
Analysis (31P NMR) of the reaction mixture before work-up showed
a resonance at dp 81.6 corresponding to 3 (R ¼ Me) but not the
downfield singlet at dp 93.6 found for 4. There was no trace of the
butyl Ru{C^CCBu]C(CN)2}(dppe)Cp* 3 (R ¼ Bu) which implies all
the LiBu had reacted with the THF. Further attack on aldehyde K by
In 7 (Fig. 4), the RueC(1)eC(2)eC(3) separations [1.963(3),
ꢂ
ꢀ
1.232(4), 1.387(4) A] and angles at C(1) and C(2) [178.3(2), 168.3(3) ]
are again consistent with the presence of the RueC^Ce fragment,
which is attached to a C4N2 ring at C(3) (crystallographic numbering).
The ring geometry, with multiple bonds between C(3)eC(4)
ꢀ
ꢀ
ꢀ
[1.282(4) A], N(8)eC(7) [1.377(5) A] and C(5)eC(50) [1.396(4) A], is
consistent with its formulation as a substituted dihydropyrimidine,
containing a dicyanomethylene group in the 4-position.
In both molecules, short RueC(1) bonds, together with the long
C(5)eC(50) bond in 7, suggest that there is significant charge
transfer from the electron-rich Ru centre through the conjugated
links to the ]C(CN)2 moiety, which stabilises negative charge.
Spectroscopic features of 6 and 7 are consistent with the solid-
LiOCH]CH2 [pathway (i)] and
b-cleavage of the resulting allylic
state structures. For 6, these include IR bands assigned to n(NH),
alkoxide with elimination of propane-1,3-dial gives a
g-methylene
n
(CN) (broad), n(C^C), n(CO) and n(C]C) at 3058, 2212, 1954, 1716
and 1603 cmꢁ1, respectively, and the usual NMR signature for the
intermediate L in which the negative charge is stabilised on the
C(CN)2 group. Protonation then forms 3 (R ¼ Me) [3].
Ru(dppe)Cp* moiety, including a singlet in the 31P NMR spectrum at
In a competitive reaction [pathway (ii)], protonation of K to the
vinylidene M is followed by enolisation to vinyl alcohol M. This
evolves via rapid intramolecular attack on C(1) by the oxygen to form
the six-membered pyrylium cation N (possibly the source of a strong
singlet at dP 81.9 in the reaction mixture), and subsequent deproto-
nation to give the neutral product 4. Overall, this resembles the well-
known reaction of alcohols with vinylidenes [Ru(]C]CH2)(PP)Cp]
PF6 [where PP ¼ (PPh3)2 or dppe] to give the analogous alkox-
ycarbene complexes, which in the case of HC^C(CH2)nOH (n ¼ 2, 3)
undergo intramolecular cyclisations to give the cyclic carbenes [17].
In this case, the cyclisation is driven by the thermodynamically
preferred formation of the pyrylium species 4.
d
72.9 (dppe). The HR ES-MS contains [M þ Na]þ at m/z 851.1624
(calcd 851.1626). The IR spectrum of 7 contained n(NH), n(CN),
n
(C^C) and
respectively. Besides the usual resonances for the Ru(dppe)Cp*
group, the 1H NMR spectrum contains three singlets at
1.26 (Me),
n ,
(C]C) bands at 3060, 2204, 2024 and 1644 cmꢁ1
d
2.17 (CH) and 4.19 (NH). A high resolution ES-MS of 7 confirmed the
formulation of [M þ H]þ at m/z 817.211 (calcd. 817.216).
We have considered possible routes for the formation of these
three complexes in the reaction between TCNE and the lithiated
diynyl complex. A possible route to 6, shown in Scheme 7, involves
partial hydrolysis of the tetracyanobutadienyl O derived from
Ru(C^CC^CH)(dppe)Cp* and TCNE, with one CN group being
converted to an amide (cf. Scheme 2 above). Subsequent intra-
molecular attack would generate dihydrolactam P. As there is no
obvious oxidant in the reaction mixture (except for TCNE itself), it is
proposed that loss of a proton from P generates the intermediate
pyrrole Q, which by loss of hydride in a Cannizzaro-like process
then affords 6.
2.2. Reaction between Ru(C^CC^CLi)(dppe)Cp* and TCNE
Lithiation of Ru(C^CC^CH)(dppe)Cp* with LiBu affords the
presumed intermediate Ru(C^CC^CLi)(dppe)Cp* [18] which re-
acts at ꢁ78 ꢂC with one equivalent of TCNE in THF with an imme-
diate change in colour from yellow to dark green (Scheme 6). After
It is known that TCNE reacts with {Cp*(dppe)Ru}2{m-(C^C)3} to
purification,
known
{Ru(dppe)Cp*}2{m-C^CC[]C(CN)2]C[]
give 5 (above) [19], but clearly the question remains as to how the

M.I. Bruce et al. / Journal of Organometallic Chemistry 756 (2014) 68e78
73
Scheme 5. Postulated mechanisms for the formation of 3 (R ¼ Me) and 4. [Ru*] ¼ Ru(dppe)Cp*.
triynyl complex is generated in a reaction where the initial ruthe-
nium reagent is Ru(C^CC^CH)(dppe)Cp*. A possible route to 5
might involve the hydride generated in forming 6 triggering a
reductive dimerisation of Ru(C^CC^CH)(dppe)Cp* to give
{[Cp*(dppe)Ru]C^CC]CH2}2. Electrocyclic formation of the
cyclobutene, followed by loss of ethene, could then give {Cp*(dppe)
Ru}(C^C)3{(Rudppe)Cp*} which reacts with TCNE to give the
observed 5. However, the route to 7 is not so obvious. While [2 þ 2]-
cycloaddition of TCNE to either the proto- or lithio-butadiynyle
ruthenium complex and subsequent ring-opening is an attractive
possibility, it is not clear how the ]C(CN)2 group attached to C(3) in
the resulting product might have further reacted/rearranged to
afford the observed eN]CMeeNHe portion of the ring. Further
work is necessary to clarify these interesting rearrangements.
obtained in 46% yield (Scheme 8) [20]. A second, pink, product,
isolated in only 10% yield, has now been identified as the tetra-
cyano(amino)cyclopentadienyl complex Ru{C^Cec-C]C(CN)
C(NH2)]C(CN)C(CN)2}(dppe)Cp* 9 by a single-crystal X-ray struc-
ture determination.
As can be seen from the plot of a molecule of 9 in Fig. 5, the usual
Cp*(dppe)RueC^Ce group is attached to a penta-substituted
cyclopentadienyl ligand at C(3) (crystallographic numbering) with
ꢀ
C(2)eC(3) 1.367(5) A. Within the C5 ring, C]C double bonds occur
ꢀ
between C(3)eC(7) and C(5)eC(6) [1.376(5), 1.383(5) A, respec-
tively]. Atom C(4) is displaced from the C(3)eC(7)eC(6)eC(5) plane
ꢀ
by 0.028(8) A. Substituents on the C5 ring comprise the NH2 group
ꢀ
[C(6)eN(6) 1.319(5) A] and four CN groups, one each on C(5) and
C(7) and two on C(4).
Although there is no strongly electron-withdrawing ]C(CN)2
group to accommodate charge in 9, the dimensions of the Rue
C(1)eC(2)eC(3) moiety again suggest that some charge transfer
from the Ru centre to the polycyano ligand occurs, the short Rue
2.3. Reaction between TCNE and Ru(C^CC^CI)(dppe)Cp*
The major product from the reaction between TCNE and
Ru(C^CC^CI)(dppe)Cp* has previously been described: the deep
purple complex Ru{C^CC]C(CN)2CI]C(CN)2}(dppe)Cp*
ꢀ
ꢀ
C(1) bond [1.936(4) A], long C(1)eC(2) [1.234(5) A] and short C(2)e
ꢀ
8
is
C(3) [1.367(5) A] bonds suggesting some delocalisation, with the

74
M.I. Bruce et al. / Journal of Organometallic Chemistry 756 (2014) 68e78
[Ru*]
[Ru*]
C
C
C
C
LiBu
C
CH
lithiated butadiynyl ligand in R (an intermediate in the formation of
8, and also possibly formed by lithiation of 8), which replaces a CN
group in a second molecule of TCNE to give S. Addition of water to
this potent Michael acceptor, during the reaction or work-up, forms
the five-membered ring in T, from which loss of carbonyl cyanide
OC(CN)2 then generates the observed product 9.
C
CLi
TCNE
This reaction may be related to the earlier described formation
of Ru{]C]C5(CN)3[]C(CN)2]2}(dppe)Cp* in the reactions of Age
C^CC^Ce[Ru*] or (Ph3P)AueC^CC^Ce[Ru*] with TCNE [21]. The
proposed route to the cyclic product involves attack of a silvere
tetracyanobutadienyl on TCNE, followed by an intramolecular 5-
exo-trig cyclisation and elimination of AgCN.
CN
O
Ru
C
C
NH
CN
C
CN
Ph2P
PPh2
NC
Ru
CN
NC
CN
NC
6
C
C
3. Conclusions
C
Ru
The chemistry described above has given an indication of a
range of intramolecular cyclisation reactions which may occur with
polycyanocarbon ligands on an electron-rich ruthenium centre.
While the precise mechanisms of the transformations noted here
may not presently be known (although we have endeavoured to
present plausible routes), there is scope for considerable further
studies, which will be reported in due course.
This chemistry has developed from further investigation of the
reactions of the tricyanovinyl(ethynyl)ruthenium complex Ru
{C^CC(CN)]C(CN)2}(dppe)Cp* 1 which have been described in
detail elsewhere [3]. In devising possible routes to the various
complexes described above, we have had recourse to the following
types of reactions:
CN
PPh2
Ph2P
PPh2
Ph2P
C
C
Ru
NH
Ph2P
N
5
PPh2
Me
7
Scheme 6. Reaction of lithiated Ru(C^CC^CH)(dppe)Cp* with TCNE to give 5, 6 and 7.
[Ru*] ¼ Ru(dppe)Cp*.
negative charge residing within the C(3)eC(7)eCN fragment [cf.
ꢀ
the short C(3)eC(7) bond, 1.376(5) A].
Spectroscopic data are consistent with the solid-state structure.
The IR spectrum contains
n
(NH) [3453 (br) cmꢁ1],
n
(CN) [2200w
n(C]C) bands
(sh), 2185m cmꢁ1],
n
(C^C) [1984s cmꢁ1] and
(i) Attack of Me3SiC^Cꢁ on CN(3) of 1 rather than on C(3);
(ii) Hydrolysis of a CN group to C(O)NH2, possibly by water
adsorbed on the TLC matrix during work-up;
(iii) Several intramolecular cyclisation reactions following either
(i), (ii) or replacement of CN(3) by other nucleophiles.
[1654w, 1575w, 1507m cmꢁ1]. In addition to the usual Ru(dppe)Cp*
resonances, the 1H and 13C NMR spectra contained resonances for
NH2 (dH 5.10), CN (dC 110.53, 114.46, 114.70) and ring C atoms (dC
123.87, 162.59). The ES-MS contained ions at m/z 1496 and 862,
assigned to [M þ Na þ Ru(dppe)Cp*]þ and [M þ Na]þ, respectively,
with an HR-MS measurement on the latter confirming its overall
formulation.
This complex is unusual in having a highly substituted C5 ring. A
plausible route (Scheme 9) involves initial addition of TCNE to the
As mentioned above in the discussions of the molecular struc-
tures, the various bond parameters support some charge transfer
Fig. 4. Plot of a molecule of Ru{C^Cec-C]CHC[]C(CN)2]NHCMe]N}(dppe)Cp* 7.
Some hydrogen atoms have been omitted for clarity. Selected bond parameters: Rue
C(1) 1.963(3), C(1)eC(2) 1.232(4), C(2)eC(3) 1.387(4), C(3)eN(8) 1.456(4), C(3)eC(4)
1.282(4), N(8)eC(7) 1.377(5), C(7)eN(6) 1.472(6), C(7)eC(71) 1.486(6), N(6)eC(5)
Fig. 3. Plot of a molecule of Ru{C^Cec-C]C(CN)C(O)NHC[]C(CN)2]}(dppe)Cp* 6.
Hydrogen atoms have been omitted for clarity. Selected bond parameters: RueC(1)
1.964(11), C(1)eC(2) 1.22(1), C(2)eC(3) 1.43(2), C(3)eC(4) 1.42(2), C(3)eC(7) 1.43(2),
C(4)eN(5) 1.32(1), C(4)eC(40) 1.38(2), N(5)eC(6) 1.48(2), C(6)eC(7) 1.38(2), C(6)eO(6)
ꢀ
1.414(5), C(4)eC(5) 1.433(5), C(5)eC(50) 1.396(4), C(50)eC(51,52) 1.418, 1.430(4) A.
ꢀ
1.26(2), C(40)eC(41,42) 1.41, 1.40(2) A. RueC(1)eC(2) 175.2(8), C(1)eC(2)eC(3)
RueC(1)eC(2) 178.3(2), C(1)eC(2)eC(3) 168.3(3), C(2, 4)eC(3)eN(8) 109.3, 114.7(3),
C(2)eC(3)eC(4) 135.9(4), C(3)eN(8)eC(7) 118.4(3), N(6)eC(7)eN(8) 127.0(4), N(8)e
C(7)eC(71) 110.1(4), N(6)eC(7)eC(71) 122.9(4), C(5)eN(6)eC(7) 110.6(4), N(6)eC(5)e
C(4) 119.8(3), N(6)eC(5)eC(50) 118.2(3), C(3)eC(4)eC(5) 129.3(4), N(8)eC(3)eC(4)
114.7(3)ꢂ.
166.9(12), C(2)eC(3)eC(4) 124.8(12), C(2,4)eC(3)eC(7) 129, 106(2), C(3)eC(4)eN(5)
110(1), C(3)eC(4)eC(40) 130(2), N(5)eC(4)eC(40) 120(2), C(4)eN(5)eC(6) 109(1),
N(5)eC(6)eO(6) 122(2), N(5)eC(6)eC(7) 106(2), C(7)eC(6)eO(6) 133(2), C(3)eC(7)e
C(6) 109(2), C(6)eC(7)eC(71) 125(2)ꢂ.

M.I. Bruce et al. / Journal of Organometallic Chemistry 756 (2014) 68e78
75
Scheme 7. Proposed mechanism for the formation of 6. [Ru*] ¼ Ru(dppe)Cp*.
1) BuLi
2) [I(py)2]BF4
Ru
C
C
C
C
H
Ru
C
C
C
C
I
-78oC
THF
Ph2P
Ph2P
PPh2
PPh2
TCNE
CN
C
NC
C
C
(NC)2C
CN
I
+
Ru
PPh2
C
C
Ru
PPh2
C
C
Ph2P
Ph2P
NH2
C
CN
NC
NC
8 (46%)
9 (10%)
Scheme 8. Reaction of TCNE with lithiated Ru(C^CC^CH)(dppe)Cp*.
from the electron-rich Ru centre to the polycyano ligand, it being
readily accommodated on the ]C(CN)2 groups, or more dispersed
around the CN-substituted ring. This is a common feature of com-
plexes of this type and in other cases, the polarisation results in
solvatochromism [3c]. More detailed studies are warranted,
particularly to refine the degree of charge transfer and its potential
in the field of opto-electronics.
4. Experimental
4.1. General
All reactions were carried out under dry nitrogen, although
normally no special precautions to exclude air were taken during
subsequent work-up. Common solvents were dried, distilled under

76
M.I. Bruce et al. / Journal of Organometallic Chemistry 756 (2014) 68e78
spectrometer via a 10 ml injection loop. Nitrogen was used as the
drying and nebulising gas. Elemental analyses were by Campbell
Microanalytical Laboratory, University of Otago, Dunedin, New
Zealand.
4.3. Reagents
Ru(C^CC^CH)(dppe)Cp*
[23]
and
Ru{C^CC(CN)]C(C
N)2}(dppe)Cp* [5] were made by the cited methods. TCNE was a
commercial sample.
4.4. Reactions of Ru{C^CC(CN)]C(CN)2}(dppe)Cp* 1
4.4.1. With LiC^CSiMe3
LiBu(0.13 mlof1.5 Msolutioninhexane, 0.197mmol)was addedto
a stirred solution of HC^CSiMe3 (0.037 ml, 0.262 mmol) in THF (8 ml)
at ꢁ78 ꢂC. After warming to r.t. for 1 h, Ru{C^CC(CN)]C(CN)2}(dppe)
Cp* 1 (100 mg, 0.131 mmol) was added to the solution. After 3.5 h
solvent was removed and the residue was purified by preparative TLC
(acetone-hexane, 3/7) to give a green band (Rf ¼ 0.61) containing
{[Ru(dppe)Cp*]C^Cec-C]C(C^CSiMe3)N(H/OH2)C(N]. )](CN)
}2 2(16mg,15%). X-rayqualitycrystalsweregrownfrom C6H6eMeOH.
Fig. 5. Plot of a molecule of Ru{C^Cec-C]C(CN)C(NH2)]C(CN)C(CN)2}(dppe)Cp* 9.
Hydrogen atoms and one set of atoms of the disordered Cp* ring have been omitted for
clarity. RueC(1) 1.936(4), C(1)eC(2) 1.234(5), C(2)eC(3) 1.367(5), C(3)eC(4) 1.554(6),
C(3)eC(7) 1.376(5), C(4)eC(5) 1.507(5), C(5)eC(6) 1.383(5), C(5)eC(51) 1.405(6), C(6)e
ꢀ
C(7) 1.453(5), C(6)eN(6) 1.319(5) A. RueC(1)eC(2) 176.0(3), C(1)eC(2)eC(3) 177.2(4),
C(2)eC(3)eC(4) 123.0(3), C(2)eC(3)eC(7) 130.9(4), C(3)eC(4)eC(5) 103.8(3), C(4)e
C(5)eC(6) 109.5(3), C(5)eC(6)eC(7) 108.4(3), C(3)eC(7)eC(6) 112.2(3), C(4)eC(3)e
C(7) 106.1(3), C(5)eC(6)eN(6) 127.9(4), C(7)eC(6)eN(6) 123.7(4)ꢂ.
Anal. Calcd (C96H98N6P4Ru2Si2): M, 1718. IR (nujol, cmꢁ1):
2219w, 2142w, (C^C) 2050s, 1971w (sh), (N]N) 1464vs,
1546w, 1421m, 1377s. 1H NMR (C6D6):
0.23 (s, 18H, SiMe3); 1.75 (s,
30H, Cp*), 2.18, 3.25 (2ꢃ m, 8H, 4ꢃ CH2, dppe), 3.64 (s, 2H, NH), 7.01e
7.43 (m, 40H, Ph). 13C NMR (C6D6):
0.44 (s, SiMe3), 10.99 (s, C5Me5),
29.83e30.40 (m, dppe), 93.79 (s, C5Me5), 126.01e137.24 (m, Ph). 31
n(C^N)
n
n
n(C]C)
nitrogen and degassed before use. Separations were carried out by
preparative thin-layer chromatography on glass plates
(20 ꢃ 20 cm2) coated with silica gel (Merck, 0.5 mm thick).
d
d
P
NMR (C6D6):
d
82.2 [s, 4P, 2ꢃ Ru(dppe)]. ES-MS (MeOH, m/z): 1718,
4.2. Instruments
Mþ; 635, [Ru(dppe)Cp*]þ; HR-MS: [M þ H]þ 1718.344 (calcd
1718.442).
IR spectra were obtained on a Bruker IFS28 FT-IR spectrometer.
Spectra in CH2Cl2 were obtained using a 0.5 mm path-length so-
lution cell with NaCl windows. Nujol mull spectra were obtained
from samples mounted between NaCl discs. NMR spectra were
recorded on a Varian Gemini 2000 instrument (1H at 300.145 MHz,
13C at 75.479 MHz, 31P at 121.501 MHz). Unless otherwise stated,
samples were dissolved in CDCl3 contained in 5 mm sample tubes.
Chemical shifts are given in ppm relative to internal tetrame-
thylsilane for 1H and 13C NMR spectra and external H3PO4 for 31P
NMR spectra. Electrospray mass spectra (ES-MS) were obtained
from samples dissolved in MeOH, with added NaOMe to aid ion-
isation [22]. Solutions were injected into a Fisons VG Platform II
4.4.2. With LiOCH]CH2 (a decomposition product formed by
reaction of THF with BuLi)
To
a stirred solution of Me3SiC^CC^CSiMe3 (13 mg,
0.066 mmol) in THF (6 ml) was added of LiBu (0.061 ml of 2.15 M
solution in hexane, 0.131 mmol) at ꢁ78 ꢂC. This was allowed to
warm to r.t. at which point the solution turned from colourless to a
golden-yellow colour, which faded back to colourless after about
3
h. After 5 h, Ru{C^CC(CN)]C(CN)2}(dppe)Cp* 1 (34 mg,
0.045 mmol) was added and the mixture slowly turned from purple
to yellowebrown. After 17 h, solvent was removed and the residue
Scheme 9. Possible mechanism for the formation of 9. [Ru*] ¼ Ru(dppe)Cp*.

M.I. Bruce et al. / Journal of Organometallic Chemistry 756 (2014) 68e78
77
Table 1
Crystal data and refinement details for 2, 4, 6, 7, 9.
Complex
2
4
6
7
9
CCDC #
Formula
MW
887533
705436
C44H42N2OP2Ru
777.81
887534
C46H40N4OP2Ru$0.386CH2Cl2
860.61
887535
C46H44N4P2Ru$0.30CH2Cl2
841.09
887536
C47H41N5P2Ru
838.86
C96H98N6P4Ru2Si2$2H2O
1754.04
Crystal system
Space group
Monoclinic
P21/n
9.1099(1)
19.9990(5)
24.6501(5)
Monoclinic
P21
12.4183(2)
10.4022(2)
14.2891(2)
Tetragonal
P4/n
27.107(2)
27.107(2)
11.727(5)
Monoclinic
P21/n
12.0547(10)
20.0027(4)
16.9280(10)
Triclinic
P1
ꢀ
a/A
11.7031(11)
11.9711(10)
16.2496(10)
79.336(6)
87.205(6)
67.758(8)
2070.2(3)
1.346
ꢀ
b/A
ꢀ
c/A
a
/deg.
/deg.
b
96.403(2)
98.860(2)
101.042(8)
g
/deg.
3
ꢀ
V/A
4463.0(2)
1.305
2
1823.81(5)
1.416
2
8617(4)
1.327
8
4006.2(4)
1.394
4
rc (g cmꢁ3
)
Z
2
2
m
qmax/deg.
(Mo-K
)/mmꢁ1
135
4.07 [Cu-K
64
0.56
50
0.53
62
0.55
55
0.50
a
a
]
Tmin/max
0.72
0.94
0.98/1.03
0.26 ꢃ 0.07 ꢃ 0.05
35,352
7576 (0.092)
3152
0.94
0.81
Crystal dimensions/mm3
0.27 ꢃ 0.06 ꢃ 0.05
0.39 ꢃ 0.11 ꢃ 0.05
0.37 ꢃ 0.25 ꢃ 0.15
0.27 ꢃ 0.14 ꢃ 0.12
Reflections collected
55,036
27,774
64,047
17,407
Unique reflections (Rint
Reflections (I > 2 (I))
R1 (I > 2 (I))
wR2 (all data)
)
7959 (0.051)
5535
0.055
11,439 (0.038)
8485
0.033
12,760 (0.035)
9510
0.045
8604 (0.070)
6226
0.061
s
s
0.090
0.239
0.161
0.061
0.123
0.159
was purified by preparative TLC (acetone-hexane, 3/7). Two
major bands were collected: orange (Rf ¼ 0.46) containing Ru
7.62 (m, 20H, Ph). 31P NMR (CDCl3):
d
72.9 (s, dppe). ES-MS
(MeOH þ NaOMe, m/z): 659, [C2Ru(dppe)Cp*]þ; 635, [Ru(dppe)
{C^CCMe]C(CN)2}(dppe)Cp*
3
(R
¼
Me) (8 mg, 24%) [3]
Cp*]þ High resolution MS (m/z): 851.1624, [M þ Na]þ (calcd for
.
and yellow (Rf ¼ 0.38) containing Ru{c-C]CHC[]C(CN)2]CH]C
HO}(dppe)Cp* 4 (6 mg, 17%) as a bright yellow solid. X-ray quality
crystals were grown from CH2Cl2/hexane. IR (CH2Cl2, cmꢁ1):
C46H40N4NaOP2Ru 851.1618).
Band 3 (orange, Rf ¼ 0.23) contained Ru{C^Cec-C]CHC[]C(
CN)2]NHCMe]N}(dppe)Cp* 7 (8 mg,16%). Single crystals suitable for
n
(C^N) 2194m, 2170w,
NMR (CDCl3):
1.45 (s, 15H, Cp*), 2.48, 2.74 (2ꢃ m, 2ꢃ CH2, dppe),
5.85 [dd, J(HH) ¼ 5.6, 2.3 Hz, 1H, H], 6.33 [d, J(HH) ¼ 5.6 Hz, 1H, H],
6.54 (s, 1H, H), 7.13e7.38 (m, 20H, Ph). 13C NMR (CDCl3):
10.16 (s,
n
(C]C) 1620s, 1476m, 1453s, 1436w. 1H
X-ray studies were grown from CH2Cl2/hexane. IR (CH2Cl2, cmꢁ1):
d
n
(CH) 2926m,
1529 (w). 1H NMR (CDCl3):
3H, CH), 2.13e2.18, 2.27e2.31 (2ꢃ m, 2ꢃ 2H, CH2CH2), 4.19 (s, H, NH),
n
(CN) 2204m,
n
(C^C) 2024m;
n(C]C) 1644 (w); n(NH)
d
1.26 (s, H, Me), 1.54 (s, 15H, Cp*), 2.17 (s,
d
C5Me5), 28.66e31.16 (m, dppe), 95.61 (s, C5Me5), 107.94, 124.19,
148.70, 153.53 (4ꢃ s, C), 119.17, 119.63 (2ꢃ s, CN), 127.94e137.92 (m,
7.07e7.63 (m, 20H, Ph). 31P NMR (CDCl3):
d 79.7 (s, dppe). ES-MS
(MeOH, m/z): 816, [M]þ; 635, [Ru(dppe)Cp*]þ High resolution MS
.
Ph), 217.04 (m, RueC). 31P NMR (CDCl3):
d
93.6 [s, 2P, Ru(dppe)]. ES-
(m/z): 817.211, [M ꢁ Me]þ (calcd for C45H41N4OP2Ru, 817.180).
MS (MeOH, m/z): 778, Mþ (calcd C44H42N2OP2Ru, 778); 635,
[Ru(dppe)Cp*]þ; HR-MS: [M þ H]þ 779.201 (calcd 779.189);
[M þ Na]þ 801.184 (801.171).
4.5.2. With Ru(C^CC^CI)(dppe)Cp* 8
To a solution of Ru(C^CC^CH)(dppe)Cp* (156 mg, 0.23 mmol)
in THF (10 ml) at ꢁ78 ꢂC was added LiBu (0.10 ml, 2.5 M in hexanes,
0.25 mmol) and stirred for 5 min. [I(py)2]BF4 (88 mg, 0.24 mmol)
was then added and the mixture was stirred 20 min to give a so-
lution containing Ru(C^CC^CI)(dppe)Cp* 8. TCNE (33 mg,
0.26 mmol) was added at ꢁ78 ꢂC and the vessel allowed to warm to
r.t. Solvent was removed and the residue purified by preparative
TLC (1% acetone/dichloromethane) to afford dark purple Ru
{C^CC]C(CN)2CI]C(CN)2}(dppe)Cp* (99 mg, 46%) [20] and pink
Ru{C^Cec-C]C(CN)C(NH2)]C(CN)C(CN)2}(dppe)Cp* 9 (20 mg,
10%). X-ray quality crystals were grown from CH2Cl2/hexane. Anal.
Calcd (C47H41N5P2Ru): C, 67.29; H, 4.93; N, 8.35; M, 839. Found: C,
4.5. Reactions of TCNE
4.5.1. With Ru(C^CC^CLi)(dppe)Cp*
A solution of Ru(C^CC^CH)(dppe)Cp* (50 mg, 0.07 mmol) in
THF (5 ml) was treated with LiBu (70 mL, 1.5 M solution in hexanes)
and stirred for 30 min at ꢁ78 ꢂC. TCNE (9 mg, 0.07 mmol) was
added and the mixture was stirred at ꢁ78 ꢂC for 30 min and then at
r.t. for 4 h. Solvent was removed and the residue was dissolved in
minimum amount of CH2Cl2 and purified by preparative TLC. Three
bands separated with CH2Cl2 as eluant. Band 1 (red, Rf ¼ 0.33)
66.67; H, 4.88; N, 8.16. IR (Nujol, cmꢁ1):
2200w (sh), 2185m, (C^C) 1984s, (C]C) 1654w, 1575w, 1507m.
1H NMR (CDCl3):
1.61 (s, 15H, Cp*), 2.36, 2.95 (2ꢃ m, 2ꢃ CH2,
dppe), 5.10 (s, 2H, NH2), 7.15e7.58 (m, 20H, Ph). 13C NMR (CDCl3):
n(NH) 3453 (br), n(CN)
contained {Ru(dppe)Cp*}2{m-C^CC[]C(CN)2]C[]C(CN)2]C^C} 5
n
n
(35 mg, 32%). Anal. Calcd. (C82H80N4P4Ru2): C, 68.65; H, 5.35; N,
3.81. Found: C, 68.71; H, 5.79; N, 3.72. IR (CH2Cl2, cmꢁ1):
(CN)
1.51 [t,
d
n
2208w, 2075w; n d
(C^C) 1967 (sh), 1866m. 1H NMR (CDCl3):
4J(HP) ¼ 2 Hz, 30H, Cp*], 1.98, 2.44 (2ꢃ m, 2ꢃ 4H, CH2P), 6.77e7.71
d
10.01 (C5Me5), 29.69 (m, PCH2), 96.90 (s, C5Me5), 110.53, 114.46,
114.70 (3ꢃ s, CN),123.87,162.59 (2ꢃ s, C) 127.91e134.90 (m, Ph). 31
P
(m, 40H, Ph). 31P NMR (CDCl3):
d
79.9, 81.3 [AB q, 3J(PP) ¼ 13 Hz,
dppe]. ES-MS (m/z): 1493, [M þ Na]þ; 635, [Ru(dppe)Cp*]þ
NMR (CDCl3):
d
81.2 (s, dppe). ES-MS (MeOH þ NaOMe, m/z): 1496,
.
[M þ Na þ Ru(dppe)Cp*]þ; 862, [M þ Na]þ; 635, [Ru(dppe)Cp*]þ.
HR-MS: [M þ Na]þ, 862.183 (calcd 862.177).
Band 2 (blue, Rf ¼ 0.27) afforded Ru{C^Cec-C]C(CN)C(O)NHC
[]C(CN)2]}-(dppe)Cp* 6 (10 mg, 20%). Single crystals suitable for X-
ray studies were grown from CH2Cl2/hexane. Anal. Calcd.
(C46H40N4OP2Ru): C, 66.65; H, 4.87; N, 6.76. Found: C, 66.54; H,
4.6. Structure determinations
5.44; N, 6.44. IR (CH2Cl2, cmꢁ1):
(C^C) 1954m, (CO) 1716m,
1.68 (s, 15H, Cp*), 1.76e1.83, 2.68e2.74 (2ꢃ m, 4H, CH2CH2), 7.23e
n
(NH) 3058w;
n(CN) 2212w,
n
n
n
(C]C) 1603w. 1H NMR (CDCl3):
Crystallographic data for the structures were collected at
100(2) K on CCD diffractometers fitted with Mo-Ka radiation,
d

78
M.I. Bruce et al. / Journal of Organometallic Chemistry 756 (2014) 68e78
ꢀ
ꢀ
[2] M.I. Bruce, M.A. Fox, P.J. Low, B.W. Skelton, N.N. Zaitseva, Dalton Trans. 39
(2010) 3759.
l
¼ 0.71073 A (Cu-K
a
,
l
¼ 1.54184 A, for 2). Following multi-scan
absorption corrections and solution by direct methods, the struc-
tures were refined against F2 with full-matrix least-squares using
the program SHELXL-97 [24]. Anisotropic displacement parameters
were employed for the non-hydrogen atoms. All H-atoms were
added at calculated positions and refined by use of riding models
with isotropic displacement parameters based on those of the
parent atom. Pertinent results are given in the Figures, which show
non-hydrogen atoms with 50% probability amplitude displacement
envelopes, and in Table 1.
For the crystal structure of 2, the atoms of the Cp* ring and those
of one Ph ring (22n) are both disordered over two sets of sites, each
with occupancies constrained to 0.5 after trial refinement. For 6, the
solvent was modelled as a dichloromethane molecule with a
refined occupancy of 0.386(15). For 7, the site occupancy of the
dichloromethane solvent molecule refined to 0.297(3) with ge-
ometries restrained to ideal values. For 9, the Cp* ring was
modelled as being disordered over two sets of sites with occu-
pancies refined to 0.725(4) and its complement.
[3] (a) M.I. Bruce, A. Burgun, K.A. Kramarczuk, B.K. Nicholson, C.R. Parker,
B.W. Skelton, A.H. White, N.N. Zaitseva, Dalton Trans. (2009) 33;
(b) M.I. Bruce, M.A. Fox, P.J. Low, B.K. Nicholson, C.R. Parker, W.C. Patalinghug,
B.W. Skelton, A.H. White, Organometallics 31 (2012) 2639;
(c) M.I. Bruce, A. Burgun, B.K. Nicholson, C.R. Parker, B.W. Skelton, A.H. White,
Organometallics 31 (2012) 4174.
[4] T.L. Cairns, R.A. Carboni, D.D. Coffman, V.A. Engelhardt, R.E. Heckert, E.L. Little,
E.G. McGeer, B.C. McKusick, W.J. Middleton, R.M. Scribner, C.W. Theobald,
H.E. Winberg, J. Am. Chem. Soc. 80 (1958) 2775 and following 11 papers.
[5] E. Ciganek, W.J. Linn, O.W. Webster, in: Z. Rappoport (Ed.), Chemistry of the
Cyano Group, Wiley, New York, 1970, p. 423 (Chapter 9).
[6] (a) A. Fatiadi, Synthesis (1986) 249;
(b) A. Fatiadi, Synthesis (1987) 749;
(c) A. Fatiadi, Synthesis (1987) 959.
[7] A.I. Meyers, J.C. Sircar, in: Z. Rappoport (Ed.), Chemistry of the Cyano Group,
Wiley, New York, 1970, p. 341 (Chapter 8).
[8] D.S. Donald, O.W. Webster, Adv. Heterocycl. Chem. 41 (1987) 1.
[9] R.B. King, M.S. Saran, Inorg. Chem. 14 (1975) 1018.
[10] (a) M.I. Bruce, D.N. Duffy, M.J. Liddell, M.R. Snow, E.R.T. Tiekink, J. Organomet.
Chem. 335 (1987) 365;
(b) M.I. Bruce, M.J. Liddell, M.R. Snow, E.R.T. Tiekink, Organometallics 7 (1988)
343.
[11] M.I. Bruce, A. Burgun, M.A. Fox, M. Jevric, P.J. Low, B.K. Nicholson, C.R. Parker,
B.W. Skelton, A.H. White, N.N. Zaitseva, Organometallics 32 (2013) 3286.
[12] H. Gilman, B.J. Gaj, J. Org. Chem. 22 (1957) 1165.
[13] A. Maerker, Angew. Chem. Int. Ed. Engl. 26 (1987) 972.
[14] P. Stanetty, M.D. Mihovilovic, J. Org. Chem. 62 (1997) 1514.
[15] R.E. Mulvey, V.L. Blair, W. Clegg, A.R. Kennedy, J. Klett, L. Russo, Nat. Chem. 2
(2010) 588.
[16] J. Clayden, S.A. Yasin, New J. Chem. 26 (2002) 191.
[17] (a) M.I. Bruce, A.G. Swincer, Aust. J. Chem. 33 (1980) 1471;
(b) M.I. Bruce, A.G. Swincer, B.J. Thomson, R.C. Wallis, Aust. J. Chem. 3 (1980)
2605.
[18] (a) M.I. Bruce, N. Scoleri, B.W. Skelton, J. Organomet. Chem. 696 (2011) 3473;
(b) M.I. Bruce, A. Burgun, C.R. Parker, B.W. Skelton, J. Organomet. Chem. 695
(2010) 619.
[19] M.I. Bruce, A. Burgun, C.R. Parker, unpublished work.
[20] M.I. Bruce, M. Jevric, C.R. Parker, W. Patalinghug, B.W. Skelton, A.H. White,
N.N. Zaitseva, J. Organomet. Chem. 693 (2008) 2915.
[21] M.I. Bruce, J.C. Morris, B.K. Nicholson, B.W. Skelton, A.H. White, N.N. Zaitseva,
Organometallics 30 (2011) 653.
[22] W. Henderson, J.S. McIndoe, B.K. Nicholson, P.J. Dyson, J. Chem. Soc. Dalton
Trans. (1998) 519.
[23] M.I. Bruce, B.G. Ellis, M. Gaudio, C. Lapinte, G. Melino, F. Paul, B.W. Skelton,
M.E. Smith, L. Toupet, A.H. White, Dalton Trans. (2004) 1601.
[24] SHELXL97 G.M. Sheldrick, Acta Crystallogr. A64 (2008) 112.
Acknowledgements
We thank the Australian Research Council for support of this
work and Johnson Matthey plc, Reading, UK, for a generous loan of
RuCl3$nH2O.
Appendix A. Supplementary material
CCDC 887533 (2), 705436 (4), 887534 (6), 887535 (7) and
887536 (9) contain the supplementary crystallographic data for
this paper. These data can be obtained free of charge from The
Cambridge Crystallographic Data Centre via www.ccdc.cam.ac.uk/
data_request/cif.
References
[1] (a) M.I. Bruce, Aust. J. Chem. 64 (2011) 77;
(b) M.I. Bruce, J. Organomet. Chem. 730 (2013) 3.