The first complexes with two metallacycles fused around a common aryl substituent: akimbo complexes

Article abstract of DOI:10.1021/om300545k

Following the reaction sequence i) oxidative addition of RNHC(O)C ₆H₃I₂-2,6 (R = Me, Tol) to [Pd ₂(dba)₃]·dba in the presence of chelating ligands N^∧N or XyNC (Xy = C₆H₃Me₂-2,6), ii) treatment of the resulting complexes with TlTfO or Tl(acac) (acac = acetylacetonato), and iii) insertion of unsaturated molecules (CO, XyNC, MeO₂CC≡CCO₂Me, MeC(O)CH=CH₂) into one of the Pd-C_aryl bonds of the resulting complexes allowed the synthesis of aryldipalladated complexes containing the ligands L1 = μ-C,C-{C ₆H₃C(O)NHR}-2,6, L2 = μ-C,C-{C₆H ₃C(O)NHMe}(C=NXy)₂-2,6, L3 = μ-C,O,C-{C ₆H₃C(O)NHMe}-2,6, L4 = μ-C,O,C,N-{C₆H ₃C(O)NR}-2,6, L6 = μ-C,N,C,O-{C₆H₃C(O)NR}-2- (C=O)-6, L7 = μ-C,N,C,O-{C₆H₃C(O)NR}-2-{C(CO ₂Me)=C(CO₂Me)}-6, L8 = μ-C,N,C,O-{C₆H ₃C(O)NR}-2-(C=NXy)-6 and two arylmonopalladated complexes with the ligands L5 = C,O-{C₆H₄C(O)NHMe}-2 and L9 = C,N-{C ₆H₃C(O)NTol}-2-{CH=CHC(O)Me}-6. The complex with the ligand L7 inserted CO into the second Pd-C_aryl bond to give an L10-Pd₂ complex (L10 = μ-C,N,C,O-{C₆H ₃C(O)NTol}(C=O)-2-{C(CO₂Me)=C(CO₂Me)}-6. The dipalladated species display a different environment for each palladium atom and represent the first systems containing two 5 + 5, 5 + 6, 5 + 7, or 6 + 7-membered palladacycles condensed over the central benzamide group. The two arms of the ligands L4 and L6-L8 and L10 are akimbo , and we coin this name both for the ligands and for the dimetallic complexes bearing them. The crystal structure of a [{Pd(N^∧N)}₂L6]⁺ complex has been determined.

Full text of DOI:10.1021/om300545k

Article
pubs.acs.org/Organometallics
The First Complexes with Two Metallacycles Fused Around a
Common Aryl Substituent: “Akimbo” Complexes
María-Teresa Chicote,† Inmaculada Vicente-Hernandez,† Peter G. Jones,‡ and Jose Vicente*,†
́
́
†Grupo de Química Organometal
Spain
‡Institut fur Anorganische und Analytische Chemie der Technischen Universitat Braunschweig, Postfach 3329, 38023, Braunschweig,
́
ica, Departamento de Química Inorgan
́
ica, Universidad de Murcia, Apartado 4021, 30071 Murcia,
̈
̈
Germany
S
* Supporting Information
ABSTRACT: Following the reaction sequence i) oxidative addition of RNHC(O)C6H3I2-2,6 (R
= Me, Tol) to [Pd2(dba)3]·dba in the presence of chelating ligands N∧N or XyNC (Xy =
C6H3Me2-2,6), ii) treatment of the resulting complexes with TlTfO or Tl(acac) (acac =
acetylacetonato), and iii) insertion of unsaturated molecules (CO, XyNC, MeO2CCCCO2Me,
MeC(O)CHCH2) into one of the Pd−Caryl bonds of the resulting complexes allowed the
synthesis of aryldipalladated complexes containing the ligands L1 = μ-C,C-{C6H3C(O)NHR}-2,6,
L2 = μ-C,C-{C6H3C(O)NHMe}(CNXy)2-2,6, L3 = μ-C,O,C-{C6H3C(O)NHMe}-2,6, L4 = μ-
C,O,C,N-{C6H3C(O)NR}-2,6, L6 = μ-C,N,C,O-{C6H3C(O)NR}-2-(CO)-6, L7 = μ-C,N,C,O-
{C6H3C(O)NR}-2-{C(CO2Me)C(CO2Me)}-6, L8 = μ-C,N,C,O-{C6H3C(O)NR}-2-(C
NXy)-6 and two arylmonopalladated complexes with the ligands L5 = C,O-{C6H4C(O)-
NHMe}-2 and L9 = C,N-{C6H3C(O)NTol}-2-{CHCHC(O)Me}-6. The complex with the ligand L7 inserted CO into the
second Pd−Caryl bond to give an L10-Pd2 complex (L10 = μ-C,N,C,O-{C6H3C(O)NTol}(CO)-2-{C(CO2Me)
C(CO2Me)}-6. The dipalladated species display a different environment for each palladium atom and represent the first
systems containing two 5 + 5, 5 + 6, 5 + 7, or 6 + 7-membered palladacycles condensed over the central benzamide group. The
two arms of the ligands L4 and L6-L8 and L10 are “akimbo”, and we coin this name both for the ligands and for the dimetallic
complexes bearing them. The crystal structure of a [{Pd(N∧N)}2L6]+ complex has been determined.
substituent, which we call an “akimbo” complex. It was
obtained, along with the monopalladated derivative, from the
reaction of bis(pyrazolylmethyl)pyrimidine with Li2[PdCl4],
but the mixture could not be resolved and the dipalladated
complex was identified only by a peak in its FAB-MS spectrum
corresponding to the loss of HCl.
This work reports the synthesis of the first “akimbo”
complexes, which we have prepared from 2,6-diiodo-
benzamides. In addition, the insertion of unsaturated molecules
into the Pd−Caryl bonds in these complexes has allowed the
expansion of one or both palladacycles, giving rise to systems
containing three condensed 6+5+6, 6+5+7, or 6+6+7-
membered C∧O∧N∧C “akimbo” complexes. Related to them
is a complex resulting from the 3-fold cyclopalladation of a
single benzene ring.22
INTRODUCTION
■
Arylpalladium complexes have attracted great interest over the
last decades mainly because they are involved in many
important palladium-catalyzed organic reactions.1
We are currently studying the synthesis of ortho-function-
alized aryl metal complexes and their reactivity toward
unsaturated molecules, for example isocyanides,2−4 CO,4−6
alkynes,6−8 alkenes,9,10 allenes,9,11 carbodiimides,12,13 isothio-
cyanates,5,12 nitriles,12,14 and cyanamides.12 These reactions are
of interest because they are involved in the synthesis of new
cyclometalated or pincer palladium complexes and in many
stoichiometric and catalytic palladium-mediated organic trans-
formations.2,5,7,10,15,16
A few years ago we started exploring the possibility of
synthesizing polypalladated aryl derivatives with organic
substituents ortho to each palladium atom, in the hope that
they could open the way to the palladium-catalyzed syntheses
of polycyclic organic compounds. So far, we have reported a
few tripalladated17,18 and dipalladated17,19 aryl complexes, some
of them bearing the palladium moieties in meta position to each
other. The latter belong to a rather large family of symmetrical
complexes20,21 with both palladium atoms in identical environ-
ments. Only one such complex, [μ-[2-[4,6-bis(1H-pyrazol-1-
ylmethyl)-2-pyrimidinyl]-1,3-phenylene]]dichloro dipalladi-
um,21 has been said to display both palladium atoms
coordinated to the same aryl ligand and sharing a single
RESULTS AND DISCUSSION
■
Synthesis. The new benzamides RNHC(O)C6H3I2-2,6 (R
= Me (A1), Tol (A2)) were isolated in yields of over 75% from
the reaction of HO2CC6H3I2-2,6 with SOCl2, and the
appropriate amine RNH2, following a procedure previously
described for other amides.23
Received: June 15, 2012
Published: August 14, 2012
© 2012 American Chemical Society
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Dipalladated aryl derivatives of the type [{PdI(N∧N)}2L1]
Chart 1. Ligands L1−L10 Present in Complexes 1−11,
a
(Scheme 1. L1, see Chart 1, N∧N = 4,4′-di-tert-butyl-2,2′-
Showing the Numbering Scheme
Scheme 1
a
“Akimbo” ligands are shown in red.
bipyridine (tBubpy), R = Me (1a), C6H4Me-4 (Tol) (1b); N∧N
= tetramethylethylenediamine (tmeda), R = Me (1′a)) were
obtained by oxidative addition of the appropriate diiodobenza-
mide to “Pd(dba)2” ([Pd2(dba)3]·dba; dba = dibenzylidenea-
cetone) in the presence of an excess of N∧N. While complexes
1b·H2O and 1′a were prepared in good yields at room
temperature, to isolate pure compound 1a it was necessary to
heat the reaction mixture to 50 °C. Otherwise, it was
contaminated with a complex that was difficult to remove. A
small amount of this compound could be isolated from the
solution obtained by washing the impure compound with Et2O,
Chart 2. Numbering Scheme Used in the NMR Assignment
t
of the Resonances of Bubpy Ligand and
[PdI{C6H3{C(O)NHMe}-2-I-6}tBubpy]
24
1
and its elemental analyses and H NMR spectrum suggest it
to be [PdI{C6H3{C(O)NHMe}-2-I-6}tBubpy] (Chart 2).
When A1 and excess XyNC (Xy = C6H3Me2-2,6), instead of
the N∧N ligands, were used, the oxidative addition reaction and
the insertion of one XyNC molecule in each Pd−C bond took
place, to give complex [{PdI(CNXy)2}2L2] (2a) (Scheme 1.
L2, see Chart 1).
Treatment of complexes 1a and 1′a with two equiv of TlTfO
caused the removal of only one of the iodo ligands, together
with coordination of the amide oxygen to one of the palladium
atoms, to give the five-membered palladacyclic complexes
[{Pd2I(N∧N)2}L3]TfO (Scheme 1. L3, see Chart 1, N∧N =
tBubpy (3a), tmeda (3′a)), which were isolated in ca. 90%
yield. The reaction of 1b with two equiv of TlTfO gave a
mixture containing the corresponding complex 3b along with
some impurities that we could neither identify nor remove.
Surprisingly, elimination of both iodo ligands from complexes 1
could not be achieved, even when the reaction was carried out
using an even larger excess of TlOTf (2.5:1) at 60 °C for 1 h.
Probably, the equilibrium 1 ⇆ [{Pd2I(N∧N)2}L3]+ + I−
(Scheme 2), involving decoordination/recoordination of I−
caused by the amide oxygen coordination (see below), allows
the precipitation of TlI. However, the second iodo ligand does
not participate in a similar equilibrium because of the poor
donor ability of the NHMe group.
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its removal as TlI, to give [{Pd(tBubpy)}2L4]TfO (Scheme 1;
L4, see Chart 1, R = Me (4a, 88%), Tol (4b, 93%)). Complex
4a could also be obtained (92%) by reacting 3a with one equiv
of Tl(acac). Complexes 4 are the first “akimbo” complexes of
any metal. Various dinuclear palladium complexes bearing
bridging amidinato ligands N,O-R′C(O)NR ligands,25 have
been reported but, in contrast to 4, in none of them are the two
Pd atoms coordinated to the R′ group.
Scheme 2
The isolation of 4a gave us the opportunity to treat it with
TfOH in a new attempt to synthesize the dicationic complex
[{Pd(N∧N)}2{μ-C,O,N,C-C6H3C(O)NHMe-2,6}](TfO)2,
which, as mentioned above, could not be obtained from 1a and
excess of TlTfO (1:2). However, the addition of TfOH to 4a
(1:1) produced an orange solution containing the monop-
alladated complex [Pd(L5)(tBubpy)]TfO (5a) (Scheme 1. L5,
see Chart 1) along with some impurities that we could not
identify. Complex 5a results from the protonation of both the
amide nitrogen and the C2 carbon in 4a, with concomitant
depalladation, and could be isolated pure when two equiv of
TfOH were used (1:2). After removing a small amount of
Pd(0), complex 5a precipitated (56% yield) upon concentrat-
ing the CH2Cl2 solution, while some “Pd(TfO)2(tBubpy)”
species that we could not identify remained in the red solution.
Only a few mononuclear cyclopalladated derivatives of
benzamides ArC(O)NRR′ (Ar = C6H4OMe-3, R = Me, R′
= Ph, C6H4Me-2; Ar = C6H3(OMe)2-3,4, R = Me, R′ = Ph;26
Ar = C6H2(OMe)3-2,3,4, R = H, R′ = tBu);16 Ar = Ph, R = H,
R′ = Me, Ph)27 have been isolated. In all of them, the O-
coordination of the amide group was assumed27 or established
by X-ray diffraction.16,28 We have reported the only cationic
Surprisingly, when 1a was reacted with one equiv of TlTfO a
product X was isolated from the reaction mixture, the elemental
analyses and IR spectrum of which coincided with that of 3a,
while its 1H NMR spectrum showed two singlets corresponding
t
to the Bu protons instead of the four singlets observed in 3a.
The explanation for these apparently incongruent data was that
X contained 3a contaminated with 1a. When X was dissolved,
the amount of I−, generated from the traces of 1a through the
above-mentioned equilibrium, is enough to react with 3a,
triggering the fast equilibrium 3a + I− ⇆ 1a + TfO− thus
t
making both Bubpy ligands equivalent. Indeed, the low
1
temperature (−55 °C) H NMR spectrum of X is identical
to that of 3a, probably favored by the low solubility of 1 at low
1
temperature. Also, the H NMR spectrum of a mixture of 3a
with traces of NaI is the same as that of X.
Removal of both iodo ligands from complexes 1 could be
achieved by reacting them with TlTfO and a base, for example
Tl(acac), in 1:1:1 molar ratio. In this way, the benzamidato
group, a strong donor, displaced the other iodo ligand, allowing
Scheme 3
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complex homologous to 5a, [Pd(L′5)(bpy)]TfO (where L′5 is
an aryl ligand similar to L5; bpy =2,2′-bipyridine).16 When R =
H, the reactions of benzamides or ortho-halobenzamides with a
Pd(II) or Pd(0) complex, respectively, in the presence of a base
have been proposed to occur through the intermediacy of a
monopalladacyclic benzamidato complex.29 However when the
R′ group contains a donor atom (P,30 S31) in the appropriate
position, a pincer benzamidato complex could be isolated.
Insertion Reactions. The synthesis of akimbo complexes 4
offers the first opportunity to study whether unsaturated
molecules display different tendencies to insert into their two
Pd−Caryl bonds. Complexes 4 react with excess CO or
MeO2CCCCO2Me (DMAD) or with one equiv of XyNC
to produce good yields of monoinsertion products [{Pd-
(tBubpy)}2L]TfO (Scheme 3) where L = L6, (Chart 1, R = Me
(6a), Tol (6b)), L7 (Chart 1, R = Me (7a), Tol (7b)), L8
(Scheme 3, Chart 1, R = Me (8a), Tol (8b)), respectively.
When the reactions with DMAD were carried out in 1:1 molar
ratio, variable amounts of the unreacted cyclometalated
complexes 4 were recovered. No reaction was observed
between complexes 4 and RCCR (R = Me, Et), even if an
excess of the alkyne was used, while the reaction of 4a·H2O
with PhCCH (1:1 or 1:5 molar ratios) led to mixtures of
unidentified products.
Partial depalladation occurred in the reaction of complex 4b
with methyl vinyl ketone (MVK; 1:2), which afforded for the
first time a Heck reaction product in the form of a
cyclopalladated complex [{Pd(tBubpy)(CNXy)2}L9]TfO
(Scheme 3, L9, see Chart 1 (9b)), which was isolated in
moderate yield. When the reaction was carried out using
equimolar amounts of the reagents, a mixture formed
containing 4b and 9b among other unidentified products.
Some attempts to prepare complexes resulting from a second
insertion reaction were attempted starting from 6a or 7b.
However, 6a reacted with two equiv of XyNC to give the
substitution product [{Pd2(tBubpy)(CNXy)2}L6]TfO
(Scheme 3. L6, see Chart 1, (10a)). Using equimolar amounts
of the reagents, a mixture formed containing equimolar
amounts of 6a and 10a. In contrast, when a solution of
complex 7b was stirred in a CO atmosphere for 6 h, insertion of
CO into the TolNPd−C bond produced the complex
[{Pd(tBubpy)}2L10]TfO (Scheme 3, L10, see Chart 1
(11b)), which was isolated in moderate yield.
All insertion reactions, with the exception of that leading to
11b, occurred into the C6−Pd bond. This selectivity could be
favored by the weaker Pd−O bond in complexes 4 compared to
Pd−N, facilitating the coordination of the unsaturated
molecule, prior to its migratory insertion. The weaker CO−
Pd bond in 4b with respect to that in 4a, associated with the
higher electron-withdrawing ability of Tol compared to Me,
may favor in the former the coordination of the alkyne. This
must be the reason why the reaction 4b → 7b requires less
excess of alkyne and less time to complete than the analogous
reaction 4a → 7a (1:2, 24 h vs 1:5, 48 h). When both reactions
were carried out at 80 °C, mixtures of unidentified products
formed, regardless of the molar ratio of the reagents.
It is noteworthy that the same type of CO insertion that
afforded 11b from 7b did not occur starting from 4b, to give
6b. It is possible that the electron withdrawing −C(CO2Me)
C(CO2Me)− group favors the resonance form [Pd]O−
C(Ar)N(R)[Pd] weakening the N−Pd bond and facilitating
the coordination of the second molecule of CO and,
correspondingly, its insertion into the C2−Pd bond.
Crystal Structures. The crystal structure of 6b·0.36H2O
(Figure 1) shows the two condensed palladacycles resulting
Figure 1. Crystal structure of the cation of 6b·0.36H2O. The anion
and the solvent are omitted for clarity. The thermal ellipsoids are
displayed at 50% probability. Selected bond lengths (Å) and angles
(deg): Pd(1)−C(11) 1.997(4), Pd(1)−N(1) 2.019(3), Pd(1)−N(31)
2.059(3), Pd(1)−N(41) 2.146(3), Pd(2)−C(18) 1.970(4), Pd(2)−
O(1) 2.011(3), Pd(2)−N(61) 2.059(3), Pd(2)−N(51) 2.162(3),
O(1)−C(17) 1.271(5), C(13)−C(18) 1.519(6), O(2)−C(18)
1.208(5), N(1)−C(17) 1.324(5), N(31)−Pd(1)−N(41) 77.85(12),
C(11)−Pd(1)−N(1) 79.45(15), N(51)−Pd(2)−N(61) 77.94(13),
C(18)−Pd(2)−O(1) 94.20(14), C(17)−N(1)−Pd(1) 116.5(3),
O(1)−C(17)−N(1) 122.0(3), C(17)−O(1)−Pd(2) 129.1(3),
C(13)−C(18)−Pd(2) 119.4(3).
from the insertion of CO into the C−Pd bond of the C,O-ring
in its precursor. The longer Pd(1)−N(41) and Pd(2)−N(51)
bond distances (2.146(3) and 2.162(3) Å, respectively)
compared to Pd(1)−N(31) and Pd(2)−N(61) (2.059(3) and
2.059(3) Å, respectively), are consistent with the greater trans
influence of carbon- with respect to nitrogen- or oxygen-donor
ligands. The seventeen atoms comprising the four palladacycles
are roughly in a plane (mean deviation 0.15 Å), with respect to
which the C(11)−C(16) and C(21)−C(26) aryl groups are
rotated by 18.6 and 72.4°, respectively.
The number of structurally characterized benzamido or
benzamidato complexes of palladium is rather limited. In fact,
only one crystal structure has been reported of a mononuclear
C,N-benzamidato complex32 and five complexes containing C-
monocoordinated33 or C,O-chelating benzamide ligands.16,26
the later being trifluoroacetato-bridged dimeric complexes.26
The structure of 6b·0.36H2O shows for the first time a
benzamidato ligand acting, simultaneously, as chelating and
bridging in a monomeric dipalladated complex.
The crystal structure of 7b was also measured and the
connectivity of the cation could be established unambiguously,
proving that insertion of DMAD occurs also into the C−Pd
bond of the C,O-ring. However, it was impossible to refine it
satisfactorily (wR2 about 35%) even after measuring various
crystals which all presented the same problems, i.e. i) the
structure is very large, consisting of two independent molecules,
ii) some butyl groups are disordered, iii) the −CO2Me groups
have high thermal parameters, and iv) one of the two triflate
anions is badly disordered.
NMR Spectra. The NMR resonances were assigned based
on APT, HMBC, and HMQC experiments carried out for
complexes 5a, 6b, 8b, 9b, and 11b. Complex 2a decomposed
upon standing in solution, which impeded the measurement of
its 13C NMR spectrum. The C2 resonances are not observed in
the 13C NMR spectra of complexes 8. A sample of complex 11b
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was prepared using 13CO in order to assign its NMR spectra
unambiguously. The inequivalence of the two halves of the
N∧N ligands is shown by the duplication of some of the
resonances, although some others accidentally coincide.
However, the spectra of 1a does not show such duplication,
indicating the interchange of positions of the two nitrogens.
This process could be facilitated by the fast equilibrium 1a ⇆
[{Pd2I(tBubpy)2}L3]+ + I− (Scheme 2), which could occur
through a planar trigonal intermediate [{Pd2I(tBubpy)2}L1]I in
which the interchange would take place. Such equivalence is
not observed in the case of 1b, probably because of the poorer
donor ability of the carbonyl amide group caused by the
electron-withdrawing nature of the Tol group.
Replacement of the iodine atoms in A1 and A2 by two
PdI(tBubpy) groups in complexes 1a,b causes a marked
deshielding of the C2+6 resonance (from ∼92 to ∼149 ppm,
Δδ ≈ 57 ppm), but the C7 resonance changes only slightly (Δδ
= 3 ppm). The behavior of these complexes in solution differs
from that of the homologous 1′a which, at room temperature,
displays very broad 13C NMR resonances suggesting a fluxional
process. At −50 °C, the C2 and C6 nuclei are inequivalent
(150.2 and 155.7 ppm, respectively) and, along with C7 (180.1
ppm), more deshielded than those in 1a,b. The low
temperature spectrum of 1′a is very similar to those of
complexes 3 in which the amide oxygen is coordinated to
palladium. This suggests that in complex 1′a the equilibrium
1′a ⇆ [{Pd2I(tmeda)2}L3]+ + I− (Scheme 2) at low
temperature is displaced toward the right.
to Pd causes the ν(CO) band to shift from 1643 (1a) to 1631
cm−1 in 1′a or to 1615−1598 cm−1 in the remaining complexes,
as previously found in other benzamido complexes.16,35 The
ν(CN) and ν(CN) bands in the isocyanide (2a, 10a) and
in the iminobenzoyl (2a, 8) complexes appear in the ranges
2170−2184 and 1642−1662 cm−1, respectively and the
νasym(CO2) in complexes with inserted DMAD (7, 11b) at
1702−1722 cm−1. The ν(CO) band in complex 11b (1819
cm−1) was unambiguously assigned to the benzoyl ν(CO)
since it shifts to 1778 cm−1 when the spectrum is measured on
a sample prepared using labeled 13CO.
EXPERIMENTAL SECTION
■
General Procedures. When not stated, the reactions were carried
out at room temperature without precautions to exclude light or
atmospheric oxygen or moisture. NMR spectra were recorded on
Bruker Avance 300 or 400 spectrometers, at 298 K, unless otherwise
stated. Chemical shifts are referred to internal TMS (1H and 13C-
1
{1H}). The assignments of the H and 13C{1H} NMR spectra were
made with the help of APT, HMBC, and HMQC experiments.
Melting points were determined on a Reichert apparatus and are
uncorrected. Elemental analyses were carried out with a Carlo Erba
1106 microanalyzer. Infrared spectra were recorded in the range
4000−200 cm−1 on a Perkin-Elmer Spectrum 100 spectrophotometer
using Nujol mulls between polyethylene sheets. High-resolution ESI
mass spectra were recorded on an Agilent 6220 Accurate-Mass TOF
LC/MS. Molar conductivities were measured on about 5 × 10−4
mol·L−1 acetone solutions with a Crison Micro CM2200 conductim-
eter. Synthesis grade solvents were obtained from commercial sources.
Toluene, CH2Cl2, and THF were degassed and dried using a Pure Solv
MD-5 solvent purification system from Innovative Technology, Inc.
CO (Air Products); TfOH, XyNC (Xy = C6H3Me2-2,6, xylyl), tmeda
(N,N,N′,N′-tetramethylethylenediamine), SOCl2, MVK (methyl vinyl
Compared to 3, complexes 4 bearing anionic amide ligands
show the C7 resonance further deshielded (up to Δδ = 10
ppm), while the C2 and C6 resonances are shielded
(approximately 10 ppm), which could be attributed to the
electron delocalization in complexes 4 allowed by the planarity
of the palladacycles.
Based on NMR correlation experiments, we can assess that
the insertion of CO, DMAD, or XyNC occurs in the C6−Pd
(Chart 1) bond of complexes 4 to give complexes 6−8,
respectively which was confirmed for 6b in the solid state by its
crystal structure (see above).
t
ketone) (Fluka), MeNH2 (33 wt % in abs EtOH), Bubpy (4,4′-tert-
butyl-2,2′-bipyridine) (Aldrich), TolNH2 (Merck), and DMAD
(DiMethyl Acetylene Dicarboxylate) (Alfa Aesar) were obtained
from commercial sources. TlTfO was prepared by reacting of Tl2CO3
(Fluka) with TfOH (1:2) in water and recrystallized from acetone/
Et2O. The compounds [Pd2(dba)3]·dba (dba = dibenzylideneace-
tone),36 Tl(acac) (acacH = acetylacetone),37 and 2,6-diiodobenzoic
acid38 were prepared according to published procedures. All other
reagents were obtained from commercial sources and used without
further purification.
In complexes 6−8 and 10a the C2 and C6 resonances appear
in the ranges 131.0−133.6 and 150.6−159.3 ppm, respectively,
while 11b shows these resonances at 132.2 and 138.3 ppm,
respectively, the former appearing in the APT spectrum of a
sample prepared from 13CO as a doublet (1JCC = 64 Hz) with
inverted polarity, which is indicative of C2 being contiguous to
the inserted 13CO.34 The −C(CO2Me)CCO2Me group in
11b seems to withdraw electron density from the acyl group,
causing both the higher shielding of C6 with respect to its
precursor 7b and the large shift of the ν(CO) band in 11b
(1819 cm−1) compared to that in the other acyl complexes (6
and 10a, ca. 1645 cm−1).
The NMR correlation experiments did not unambiguously
determine which of the tBubpy ligands in 6a is replaced by two
XyNC ligands to give 10a, but we tentatively assign it the
structure depicted in Scheme 3, based on our assumption that
in this way the substitution is facilitated by the weaker Pd−O
bond.
Synthesis of RNHC(O)C6H3I2-2,6 (R = Me (A1), Tol (A2)).
SOCl2 (for A1: 2.80 mL, 38.7 mmol; for A2: 2.18 mL, 30.8 mmol) was
added dropwise under nitrogen to a stirred solution of HO2CC6H3I2-
2,6 (for A1: 804.0 mg, 2.50 mmol; for A2: 639 mg, 1.70 mmol) in
CH2Cl2 (20 mL). The solution was refluxed for 3 (A1) or 4 h (A2),
cooled to room temperature, and concentrated under vacuum to give a
pale yellow oil. Ethyl acetate (for A1: 3 mL; for A2: 2 mL) and a
solution of the appropriate amine (for A1: MeNH2, 3.8 mL, 30.10
mmol; for A2: TolNH2, 1.47 g, 13.70 mmol) in MeOH (for A1: 5
mL) or CH2Cl2 (for A2: 2 mL) were successively added dropwise.
After 5 min of stirring, the mixture was treated with an aqueous
solution of K2CO3 (for A1: 500.0 mg/80 mL; for A2: 400.0 mg/60
mL) and stirred for 5 min. For A1, the suspension was filtered, and the
solid was washed with water (2 × 5 mL) and vacuum-dried to give a
white powder. For A2, the solvent was poured off, the residue was
washed with water (3 × 10 mL), and the suspension was filtered. After
air drying the solid, it was stirred in n-hexane, the suspension was
filtered, and the solid was dissolved in CH2Cl2 (30 mL), filtered
through anhydrous MgSO4, and concentrated to 2 mL. Upon the
addition of n-hexane (30 mL) a suspension formed, which was filtered;
the solid was vacuum-dried to give a white powder.
IR Spectra. The variable position of the NH stretching
bands, appearing in the in the range 3219−3347 cm−1 in the IR
spectra of benzamides A1,2 and benzamido complexes 1−3 and
5, could be associated with the participation of the NH group in
intermolecular hydrogen bonding to the CO group (1) or
the triflato anion (3, 5). Coordination of the benzamide oxygen
A1: Yield: 613.0 mg, 74%. Mp: 241 °C. 1H NMR (300 MHz,
CDCl3): δ 7.79 (d, 2 H, H3+5, 3JHH = 8 Hz), 6.73 (t, 1 H, H4, 3JHH = 8
3
Hz), 5.61 (br, 1 H, NH), 3.05 (d, 3 H, Me, JHH = 5 Hz). 13C{1H}
NMR APT (75 MHz, CDCl3): δ 170.5 (C7), 147.4 (C1), 138.9 (C3+5),
6256
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Organometallics
Article
131.7 (C4), 92.2 (C2+6), 26.7 (Me). IR (cm−1): ν(NH), 3258; ν(CO),
1650. Anal. Calcd for C8H7I2NO: C, 24.83; H, 1.82; N, 3.62. Found:
C, 25.05; H, 1.61; N, 3.56.
filtrate was concentrated to 2 mL, Et2O (25 mL) was added, the
suspension was filtered, and the solid was washed with Et2O (3 × 5
mL) and dried, first by suction and then in an oven at 60 °C for 24 h,
to give 2a as a yellow powder. Yield: 163.0 mg, 45%. Mp: 179 °C
A2: Yield: 715.2 mg, 90%. Mp: 259 °C. 1H NMR (300 MHz,
CDCl3): δ 7.84 (d, 2 H, H3+5, 3JHH = 8 Hz), 7.52 (d, 2 H, o-CH, Tol,
3JHH = 8 Hz), 7.21 (d, 2 H, m-CH, Tol, 3JHH = 8 Hz), 6.78 (t, 1 H, H4,
3JHH = 8 Hz), 2.36 (s, 3 H, Me). 13C{1H} NMR APT (75 MHz,
CDCl3): δ 167.6 (C7), 147.0 (C1), 139.0 (C3+5), 135.1 (p-C, Tol),
134.4 (i-C, Tol), 132.0 (C4), 129.7 (m-C, Tol), 120.7 (o-C, Tol), 92.3
(C2+6), 21.0 (Me). IR (cm−1): ν(NH), 3252; ν(CO), 1656. Anal.
Calcd for C14H11I2NO: C, 36.31; H, 2.39; N, 3.02. Found: C, 36.05;
H, 2.23; N, 3.23.
1
3
(dec). H NMR (300 MHz, CDCl3): δ 7.77 (d, 2 H, H3+5, JHH = 8
Hz), 7.47 (t, 1 H, H4, 3JHH = 8 Hz), 7.19 (t, 4 H, p-CH, Xy, 3JHH = 8
3
Hz), 7.03 (d, 8 H, m-CH, Xy, JHH = 8 Hz), 6.84 (s, 6 H, CH, Xy),
6.65 (q, 1 H, NH, 3JHH = 5 Hz), 2.95 (d, 3 H, Me, 3JHH = 5 Hz), 2.21
(s, 24 H, Me, Xy), 2.17 (s, 12 H, Me, Xy). IR (cm−1): ν(NH), 3347;
ν(CN), 2184, 2175; ν(CN), 1662; ν(CO), 1636. Anal. Calcd for
C62H61I2N7OPd2: C, 53.70; H, 4.43; N, 7.07. Found: C, 53.87; H,
4.74; N, 7.06.
Synthesis of [{Pd2I(N∧N)2}L3]TfO (L3 = μ-C,O,C-{C6H3C(O)-
NHMe}-2,6, N∧N = tBubpy (3a), tmeda (3′a)). To a solution of the
appropriate compound 1 (for 3a: 1a, 300.0 mg, 0.26 mmol; for 3′a: 1c,
200.0 mg, 0.26 mmol) in dry CH2Cl2 (15 mL) was added TlTfO (for
3a: 233.3 mg, 0.66 mmol; for 3′a: 170.0 mg, 0.48 mmol). The
resulting suspension was stirred for 30 min and filtered through Celite.
The solution was concentrated to 2 mL, Et2O (25 mL) was added, and
the suspension was filtered. The solid was suction dried to give the
appropriate compound 3 as an orange powder.
t
Synthesis of [{PdI(N∧N)}2L1] (N∧N = Bubpy, L1 = μ-C,C-
{C6H3C(O)NHR}-2,6, R = Me (1a), Tol (1b); N∧N = tmeda, R = Me,
(1′a)). A suspension containing Pd(dba)2 (for 1a: 646.4 mg, 1.12
mmol; for 1b: 1.5 g, 2.66 mmol; for 1′a: 743 mg, 1.29 mmol), the
t
appropriate N∧N ligand (for 1a: Bubpy, 805.0 mg, 3 mmol; for 1b:
950.0 mg, 3.54 mmol; for 1′a: tmeda, 311 μL, 2.07 mmol), and the
appropriate compound A (for 1a: A1, 145.0 mg, 0.37 mmol; for 1b:
A2, 410.0 mg, 0.88 mmol; for 1′a: A1, 200.0 mg, 0.52 mmol) in dry
toluene (20 mL) was stirred under nitrogen atmosphere for 5 h or
heated in a Carius tube at 50 °C for 4 h (1a). The solvent was
removed under vacuum, and the residue was extracted with CH2Cl2
(20 mL) and filtered through Celite. The filtrate was concentrated
under vacuum to 2 mL, the residue was stirred for 10 min with Et2O
(25 mL, for 1b in an ice/water bath) or n-hexane (1a, 30 mL), and the
suspension was filtered. The solid collected was washed with hot n-
hexane (10 × 15 mL) and dried under vacuum to give an orange solid.
In the case of 1b, the hydrate 1b·H2O was obtained in spite of drying
the solid in a vacuum oven at 60 °C for 14 h. 1′a was recrystallized
from CH2Cl2/Et2O (2:25 mL) and dried by suction.
3a: Yield: 272.0 mg, 89%. Mp: 202 °C (dec). 1H NMR (400 MHz,
CDCl3): δ 9.99 (q, 1 H, NH, 3JHH = 5 Hz), 9.47 (d, 1 H, He, 3JHH = 6
3
3
Hz), 8.90 (d, 1 H, He, JHH = 6 Hz), 8.70 (d, 1 H, He, JHH = 6 Hz),
8.16 (s, br, 2 H, Hb), 8.09 (d, 1 H, Hb, 4JHH = 2 Hz), 8.05 (d, 1 H, Hb,
4JHH = 2 Hz), 7.72 (m, 2 H, Hd), 7.58 (dd, 1 H, Hd, 3JHH = 6 Hz, 4JHH
= 2 Hz), 7.54 (d, 1 H, H3 or 5, 3JHH = 8 Hz), 7.37 (dd, 1H, Hd, 3JHH = 6
Hz, 4JHH = 2 Hz), 7.06 (d, 1 H, He, 3JHH = 6 Hz), 6.95 (t, 1 H, H4, 3JHH
= 8 Hz), 6.89 (d, 1 H, H3 or 5, 3JHH = 8 Hz), 3.07 (d, 3 H, Me, 3JHH = 5
Hz), 1.50 (s, 9 H, CMe3), 1.48 (s, 9 H, CMe3), 1.47 (s, 9 H, CMe3),
1.38 (s, 9 H, CMe3). 13C{1H} NMR APT (100 MHz, CDCl3): δ 180.6
(C7), 164.7 (Cc), 164.5 (Cc), 164.3 (Cc), 157.2 (C6), 156.7 (Ca), 155.8
(Ca), 154.1 (Ca), 152.9 (Ca), 152.2 (Ce), 151.2 (Ce), 149.9 (C2), 149.0
(Ce), 148.4 (Ce), 144.2 (C1), 133.3 (C3 or 5), 130.3 (C3 or 5), 126.9
(C4), 124.6 (Cd), 124.4 (Cd), 124.3 (Cd), 124.2 (Cd), 120.4 (Cb),
119.2 (Cb), 119.1 (Cb), 118.9 (Cb), 35.9 (CMe3), 35.8 (CMe3), 35.6
(CMe3), 30.4 (CMe3), 30.3 (CMe3), 30.3 (CMe3), 30.1 (CMe3), 27.3
(Me). IR (cm−1): ν(NH), 3233; ν(CO), 1611. ΛM (Ω−1·cm2·mol−1):
132. Anal. Calcd for C45H55F3IN5O4Pd2S: C, 46.64; H, 4.78; N, 6.04;
S, 2.77. Found: C, 46.61; H, 4.88; N, 5.93; S, 2.45.
1a: Yield: 363.0 mg, 85%. Mp: 171 °C (dec). 1H NMR (400 MHz,
CDCl3): δ 9.46 (br, 4 H, Hb), 7.93 (br, 4 H, He), 7.47 (dd, 4 H, Hd,
3JHH = 6 Hz, 4JHH = 2 Hz), 7.26 (d, 2 H, H3+5, 3JHH = 7 Hz), 6.70 (t, 1
3
3
H, H4, JHH = 7 Hz), 2.75 (d, 3 H, Me, JHH = 5 Hz), 1.40 (br, 36 H,
CMe3). 13C{1H} NMR APT (75 MHz, CDCl3): δ 173.0 (C7), 163.1−
162.6 (Cc), 148.9 (C2+6), 132.6 (C3+5), 126.5 (C4), 123.8 (br, Cd),
118.2 (br,Ce), 35.4 (CMe3), 30.3 (CMe3), 26.3 (Me). IR (cm−1):
ν(NH), 3233; ν(CO), 1643. Anal. Calcd for C44H55I2N5OPd2: C,
46.50; H, 4.88; N, 6.16. Found: C, 46.23; H, 4.76; N, 5.78.
3′a: Yield: 186.0 mg, 91%. Mp: 138 °C (dec). 1H NMR (300 MHz,
1
1b·H2O: Yield: 865.0 mg, 80%. Mp: 228 °C (dec). H NMR (400
3
CDCl3): δ 10.26 (q, 1 H, NH, JHH = 5 Hz), 7.38 (d, 1 H, CH3 or 5
,
,
MHz, CDCl3): δ 9.45 (br, 3 H, NH + Hb), 7.85 (br, 6 H, Hb + He),
3
3JHH = 8 Hz), 6.80 (t, 1 H, C4, JHH = 8 Hz), 6.52 (d, 1 H, CH3 or 5
7.55 (d, 2 H, Tol, 3JHH = 8 Hz), 7.43 (dd, 4 H, Hd, 3JHH = 6 Hz, 4JHH
=
2 Hz), 7.34 (d, 2 H, H3+5, JHH = 8 Hz), 6.82 (d, 2 H, Tol, JHH = 8
Hz), 6.70 (t, 1 H, H4, 3JHH = 8 Hz), 2.11 (s, 3 H, Me, Tol), 1.73 (s, 2
H, H2O), 1.39 (s, 18 H, CMe3), 1.32 (s, 18 H, CMe3). 13C{1H} NMR
APT (75 MHz, CDCl3): δ 169.3 (C7), 162.7 (Cc), 155.3 (Ca), 154.1
(Ca), 152.3 (Cb), 150.6 (Cb), 147.9 (C2+6), 145.4 (C1), 137.2 (i-C,
Tol), 133.7 (C3+5), 131.5 (p-C, Tol), 128.5 (m-C, Tol), 126.0 (C4),
123.9 (Cd), 123.4 (Cd), 119.1 (o-C, Tol), 118.0 (Ce), 117.7 (Ce), 35.3
(CMe3), 30.3 (CMe3), 30.2 (CMe3), 20.6 (Me, Tol). IR (cm−1):
ν(NH), 3305; ν(CO), 1661. Anal. Calcd for C50H61I2N5O2Pd2: C,
48.80; H, 5.00; N, 5.69. Found: C, 48.50; H, 4.76; N, 5.55.
3
3
3
3JHH = 8 Hz), 3.16 (d, 3 H, Me, JHH = 5 Hz), 2.94 (s, br, 5 H, Me +
CH2, tmeda), 2.90 (s, br, 5 H, Me + CH2, tmeda), 2.75 (s, br, 13 H, 3
Me + 2 CH2, tmeda), 2.69 (s, br, 3 H, Me, tmeda), 2.31 (s, 3 H, Me,
tmeda), 2.18 (s, 3 H, Me, tmeda). 13C{1H} NMR APT (75 MHz,
CDCl3): δ 180.7 (C7), 154.8 (C6), 150.4 (C2), 144.6 (C1), 133.8
(C3 or 5), 129.3 (C4), 126.1 (C3 or 5), 65.2 (CH2), 62.3 (CH2), 58.6
(CH2), 57.4 (CH2), 51.9 (Me, tmeda), 51.7 (Me, tmeda), 50.7 (Me,
tmeda), 50.6 (Me, tmeda), 49.6 (Me, tmeda), 49.1 (Me, tmeda), 48.2
(Me, tmeda), 47.8 (Me, tmeda), 26.9 (Me). IR (cm−1): ν(NH), 3219;
ν(CO), 1598. ΛM (Ω−1·cm2·mol−1): 129.4. Anal. Calcd for
C21H39F3IN5O4Pd2S: C, 29.52; H, 4.60; N, 8.20; S, 3.75. Found: C,
29.14; H, 4.36; N, 8.04; S, 3.54.
1′a: Yield: 366.0 mg, 85%. Mp: 140 °C (dec). 1H NMR (200 MHz,
CDCl3, −50 °C): δ 6.91 (d, 2 H, H3+5, 3JHH = 7 Hz), 6.67 (t, 1 H, H4,
3JHH = 7 Hz), 3.14 (d, 3 H, Me, JHH = 5 Hz), 2.76 (br, 8 H, CH2,
3
Synthesis of [{Pd(tBubpy)}2L4]TfO (L4 = μ-C,O,C,N-{C6H3C-
(O)NMe}-2,6 (4a)). To a solution of 3a (72.0 mg, 0.06 mmol) in
acetone (20 mL) was added Tl(acac) (37.7 mg, 0.12 mmol). The
resulting suspension was stirred for 45 min, and the solvent was
removed under vacuum. The residue was extracted with CH2Cl2 (25
mL), and the suspension was filtered through Celite. The solution was
concentrated to 1 mL, Et2O (25 mL) was added, and the suspension
was filtered. The solid was washed with Et2O (2 × 5 mL) and dried
first by suction and then in a vacuum oven at 80 °C for 4 h to give
4a·H2O as a yellow powder. Yield: 58.0 mg, 92%. Mp: 210 °C (dec).
tmeda), 2.62 (br, 24 H, Me, tmeda). 13C{1H} NMR APT (100 MHz,
CDCl3): δ 128.1 (C3+5), 61.8 (CH2), 52.7 (Me, tmeda), 26.9 (Me).
13C{1H} NMR APT (75 MHz, CDCl3, −50 °C): δ 180.1 (C7), 155.7
(C6), 150.2 (C2), 144.2 (C1), 129.4 (C4), 125.8 (C3+5), 64.8 (CH2),
62.0 (CH2), 58.2 (CH2), 57.0 (CH2), 54.0−45.0 (Me, tmeda), 27.7
(Me). IR (cm−1): ν(NH), 3218; ν(CO), 1631. Anal. Calcd for
C20H39I2N5OPd2: C, 28.87; H, 4.72; N, 8.42. Found: C, 28.73; H,
4.90; N, 8.40.
Synthesis of [trans-{PdI(CNXy)2}2L2] (L2 = μ-C,C-{C6H3C(O)-
NHMe}(CNXy)2-2,6 (2a)). A suspension containing Pd(dba)2
(297.2 mg, 0.52 mmol), XyNC (237.4 mg, 1.81 mmol), and A1
(100 mg, 0.26 mmol) in dry toluene (20 mL) was stirred for 15 h. The
solvent was removed under vacuum, and the residue was extracted
with CH2Cl2 (20 mL). The suspension was filtered through Celite, the
3
1H NMR (400 MHz, CDCl3): δ 8.95 (d, 1H, He, JHH = 6 Hz), 8.82
(d, 1 H, He, 3JHH = 6 Hz), 8.81 (d, 1 H, He, 3JHH = 6 Hz), 8.67 (d, 1 H,
He, 3JHH = 6 Hz), 8.15 (d, 1 H, Hb, 4JHH = 2 Hz), 8.12 (s, br, 2 H, Hb),
8.09 (d, 1 H, Hb, 4JHH = 2 Hz), 7.75 (dd, 1 H, Hd, 3JHH = 6 Hz, 4JHH
=
2 Hz), 7.64 (dd, 1 H, Hd, 3JHH = 6 Hz, 4JHH = 2 Hz), 7.60 (dd, 2 H, Hd,
6257
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1
3JHH = 6 Hz, 4JHH = 2 Hz), 6.91 (d, 1 H, H3 or 5, 3JHH = 7 Hz), 6.84 (d,
6a·H2O: Yield: 493.0 mg, 95 Mp: 228 °C (dec). H NMR (300
MHz, CDCl3): δ 9.07 (d, 2 H, He, JHH = 6 Hz), 8.87−8.83 (m, 2 H,
3
1 H, H3 or 5, 3JHH = 7 Hz), 6.80 (t, 1 H, H4, 3JHH = 7 Hz), 3.16 (s, 3 H,
Me), 1.57 (s, 2 H, H2O), 1.478−1.47 (s, br, 36 H, CMe3). 13C{1H}
APT NMR (100 MHz, CDCl3): δ 190.9 (C7), 164.7 (Cc), 164.6 (Cc),
164.5 (Cc), 162.5 (C1), 157.0 (Ca), 156.4 (Ca), 154.5 (Ca), 153.1 (Ca),
152.1 (Ce), 151.2 (Ce), 149.6 (Ce), 148.6 (Ce), 143.4 (C2 or 6), 141.9
(C2 or 6), 127.1 (C3 or 5), 126.2 (C4), 125.9 (C3 or 5), 124.2 (Cd), 123.8
(Cd), 123.7 (Cd), 120.0 (Cb), 119.8 (Cb), 119.2 (Cb), 118.7 (Cb),
35.8−35.7 (CMe3), 34.3 (Me), 30.4−30.2 (CMe3). IR (cm−1): ν(CO),
1611. ΛM (Ω−1·cm2·mol−1): 123. Anal. Calcd for C45H56F3N5O5Pd2S:
C, 51.53; H, 5.38; N, 6.68; S, 3.06. Found: C, 51.45; H, 5.36; N, 6.58;
S, 2.74.
He), 8.07 (br, 1 H, Hb), 8.05 (br, 1 H, Hb), 8.01 (d, 1 H, Hb, 4JHH = 2
Hz), 8.00 (d, 1 H, Hb, JHH = 2 Hz), 7.92 (d, 1 H, Hd, JHH = 6 Hz),
7.81 (dd, 1 H, Hd, 3JHH = 6 Hz, 4JHH = 2 Hz), 7.63−7.61 (m, 2 H, Hd),
7.34 (d, 1 H, H3, 3JHH = 7 Hz), 7.21 (d, 1 H, H5, 3JHH = 7 Hz), 7.09 (t,
1 H, H4, 3JHH = 7 Hz), 3.60 (s, 3 H, Me), 1.57 (s, 2 H, H2O), 1.50 (s, 9
H, CMe3), 1.49 (s, 9 H, CMe3), 1.46 (s, 9 H, CMe3), 1.45 (s, 9 H,
CMe3). 13C{1H} APT NMR (75 MHz, CDCl3): δ 218.6 (CO),
175.7 (C7), 164.8 (Cc), 164.5 (Cc), 164.4 (Cc), 164.2 (Cc), 156.3 (Ca),
155.2 (Ca), 154.2 (Ca), 153.7 (C6), 152.6 (Ca), 151.5 (Ce), 150.6 (Ce),
150.2 (Ce), 147.6 (Ce), 143.2 (C1), 135.6 (C3), 131.6 (C2), 130.2
(C4), 124.9 (Cd), 124.1 (Cd), 124.0 (Cd), 123.3 (Cd), 121.3 (C5),
119.8 (Cb), 119.0 (Cb), 118.9 (Cb), 118.1 (Cb), 37.0 (Me), 35.7
(CMe3), 35.5 (CMe3), 30.3 (CMe3). IR (cm−1): ν(CO), 1643, 1612.
ΛM (Ω−1·cm2·mol−1): 126. Anal. Calcd for C46H56F3N5O6Pd2S: C,
51.31; H, 5.24; N, 6.50; S, 2.98. Found: C, 51.13; H, 4.86; N, 6.40; S,
3.19.
4
3
Synthesis of [{Pd(tBubpy)}2L4]TfO (L4 = μ-C,O,C,N-{C6H3C-
(O)NTol}-2,6 (4b)). To a solution of 1b·H2O (243.0 mg, 0.20 mmol)
in acetone (20 mL) was added TlTfO (70.8 mg, 0.20 mmol) and
Tl(acac) (60.8 mg, 0.20 mmol). The resulting suspension was stirred
for 1 h and filtered through Celite. The solution was concentrated to 1
mL, Et2O (25 mL) was added, and the suspension was filtered. The
solid was washed with Et2O (2 × 5 mL) and dried, first by suction and
then in an oven at 80 °C for 4 h, to give 4b·H2O as a yellow powder.
Yield: 210.0 mg, 93%. Mp: 217 °C (dec). 1H NMR (300 MHz,
1
6b·H2O: Yield: 97.0 mg, 93%. Mp: 225 °C (dec). H NMR (400
MHz, CDCl3): δ 9.12 (d, 1 H, He, 3JHH = 6 Hz), 8.95 (d, 1 H, He, 3JHH
= 6 Hz), 8.16 (d, 1 H, Hb, JHH = 2 Hz), 8.15 (d, 1 H, Hb, JHH = 2
4
4
3
3
CDCl3): δ 9.05 (d, 1H, He, JHH = 6 Hz), 8.88 (d, 1 H, He, JHH = 6
Hz), 8.01 (d, 1 H, Hb, 4JHH = 2 Hz), 7.97 (s, br, 1 H, Hb), 7.73 (d, 1 H,
Hz), 8.36 (d, 1 H, He, JHH = 6 Hz), 8.13 (d, 1 H, Hb, JHH = 2 Hz),
He, JHH = 6 Hz), 7.70 (dd, 1 H, Hd, JHH = 6 Hz, JHH = 2 Hz), 7.63
3
4
3
3
4
8.10 (br, 1 H, Hb), 8.07 (d, 1 H, Hb, JHH = 2 Hz), 8.05 (d, 1 H, Hb,
(dd, 1 H, Hd, JHH = 6 Hz, JHH = 2 Hz), 7.50 (m, 2 H, H3+5), 7.43,
4
3
4
4JHH = 2 Hz), 7.67 (dd, 1 H, Hd, 3JHH = 6 Hz, 4JHH = 2 Hz), 7.64 (dd, 1
7.41 (AAXX system, 4 H, CH, Tol, JAX = 8 Hz), 7.34 (t, 1 H, H4, 3JHH
= 8 Hz), 7.18 (dd, 1 H, Hd, 3JHH = 6 Hz, 4JHH = 2 Hz), 7.14 (dd, 1 H,
Hd, 3JHH = 6 Hz, 4JHH = 2 Hz), 6.80 (d, 1 H, He, 3JHH = 6 Hz), 2.57 (s,
3 H, Me, Tol), 1.56 (s, 2 H, H2O), 1.50 (s, 9 H, CMe3), 1.45 (s, 9 H,
CMe3), 1.42 (s, 9 H, CMe3), 1.40 (s, 9 H, CMe3). 13C{1H} APT NMR
(100 MHz, CDCl3): δ 216.8 (CO), 176.2 (C7), 165.2 (Cc), 164.8
(Cc), 164.6 (Cc), 164.5 (Cc), 156.5 (Ca), 155.1 (Ca), 154.8 (Ca), 154.2
(C6), 152.8 (Ca), 151.9 (Ce), 150.1 (Ce), 149.0 (Ce), 147.3 (Ce), 143.9
(i-C, Tol), 142.9 (C1), 136.1 (C3), 136.0 (p-C, Tol), 132.1 (C2), 131.5
(C4), 129.9 (m-C, Tol), 127.0 (o-C, Tol), 124.3 (Cd), 123.4 (Cd),
123.0 (Cd), 122.7 (Cd), 122.0 (C5), 120.3 (Cb), 119.3 (Cb), 119.1
(Cb), 118.2 (Cb), 35.8 (CMe3), 35.6 (CMe3), 35.5 (CMe3), 30.3
(CMe3), 30.2 (CMe3), 21.3 (Me, Tol). Single crystals of 6b·0.36H2O
suitable for an X-ray diffraction study were obtained by slow diffusion
of Et2O into a solution of 6b in CH2Cl2. IR (cm−1): ν(CO), 1648,
1614. ΛM (Ω−1·cm2·mol−1): 128. Anal. Calcd for C52H60F3N5O6Pd2S:
C, 54.17; H, 5.25; N, 6.07; S, 2.78. Found: C, 54.30; H, 5.15; N, 6.16;
S, 2.50.
́
́
H, Hd, 3JHH = 6 Hz, 4JHH = 2 Hz), 7.52 (dd, 1 H, Hd, 3JHH = 6 Hz, 4JHH
= 2 Hz), 7.38 (d, 2 H, o-CH, Tol, 3JHH = 8 Hz), 7.24 (d, 2 H, m-CH,
Tol, 3JHH = 8 Hz), 7.10 (dd, 1 H, Hd, 3JHH = 6 Hz, 4JHH = 2 Hz), 7.02−
6.91 (various m, 3 H, H3+4+5), 6.72 (d, 1 H, He, 3JHH = 6 Hz), 2.45 (s,
3 H, Me, Tol), 1.59 (s, 2 H, H2O), 1.49 (s, 9 H, CMe3), 1.48 (s, 9 H,
CMe3), 1.44 (s, 9 H, CMe3), 1.38 (s, 9 H, CMe3). 13C{1H} APT NMR
(75 MHz, CDCl3): δ 189.5 (C7), 164.9 (Cc), 164.9 (Cc), 164.8 (Cc),
164.3 (Cc), 162.8 (C1), 157.0 (Ca), 156.5 (Ca), 154.5 (Ca), 153.0 (Ca),
152.2 (Ce), 151.3 (Ce), 148.9 (Ce), 148.6 (Ce), 143.4 (C2 or 6), 142.7
(C2 or 6), 142.2 (i-C, Tol), 135.0 (p-C, Tol), 129.5 (m-C, Tol), 127.3
(C3 or 5), 127.2 (C3 or 5+4), 126.3 (o-C, Tol), 124.0 (Cd), 123.8 (Cd),
122.9 (Cd), 120.2 (Cb), 120.0 (Cb), 119.0 (Cb), 118.7 (Cb), 35.8
(CMe3), 35.5 (CMe3), 30.3 (CMe3), 30.2 (CMe3), 21.3 (Me, Tol). IR
(cm−1): ν(CO), 1614. ΛM (Ω−1·cm2·mol−1): 127. Anal. Calcd for
C51H60F3N5O5Pd2S: C, 54.45; H, 5.38; N, 6.28; S, 2.85. Found: C,
54.30; H, 5.52; N, 6.17; S, 2.77.
Synthesis of [PdL5(tBubpy)]TfO (L5 = C,O-{C6H4C(O)NMe}-2
(5a)). To a solution of 4a·H2O (100.0 mg, 0.10 mmol) in CH2Cl2 (10
mL) was added TfOH (17 μL, 0.19 mmol). The reaction mixture was
stirred for 2 h and filtered through Celite. Upon concentrating the
orange solution to 5 mL, a pale-yellow solid appeared. The suspension
was filtered, and the solid was washed with Et2O (3 × 5 mL) and
dried, first by suction and then in an oven at 55 °C for 10 h, to give
5a·H2O as a pale yellow powder. Yield: 36.0 mg, 56%. Mp: 218 °C
Synthesis of [{Pd(tBubpy)}2L7]TfO (L7 = μ-C,N,C,O-{C6H3C-
(O)NR}-2-{C(CO2Me)C(CO2Me)}-6, R = Me (7a), Tol (7b)). To a
solution of the appropriate complex 4 (4a·H2O, 62 mg, 0.06 mmol;
4b·H2O, 100.0 mg, 0.09 mmol) in CH2Cl2 (20 mL) was added
MeO2CCCCO2Me (for 7a: 37 μL, 0.30 mmol; for 7b: 22 μL, 0.18
mmol). The reaction mixture was stirred for 48 or 24 h, respectively,
filtered through Celite, and concentrated to 1 mL. Et2O (25 mL) was
added, and the suspension was filtered. The solid was washed with
Et2O (2 × 5 mL) and suction dried to give 7a·H2O or 7b·2H2O as a
yellow powder.
1
(dec). H NMR (400 MHz, d6-dmso): δ 9.57 (br, 1 H, NH), 8.60 (s,
br, 2 H, Hd), 8.52 (br, 2 H, He), 7.75 (br, 2 H, Hb), 7.51 (d, 1 H, H2,
3JHH = 7 Hz), 7.35 (d, 1 H, H5, 3JHH = 7 Hz), 7.30 (t, 1 H, H3, 3JHH = 7
Hz), 7.19 (t, 1 H, H4, 3JHH = 7 Hz), 3.31 (br, 2 H, H2O), 2.96 (d, 3 H,
1
7a·H2O: Yield: 44.0 mg, 62%. Mp: 195 °C (dec). H NMR (400
MHz, CDCl3): δ 8.93 (d, 1 H, He, 3JHH = 6 Hz), 8.89 (d, 1 H, He, 3JHH
3
Me, JHH = 4 Hz), 1.43 (s, 18 H, CMe3). 13C{1H} NMR APT (100
= 6 Hz), 8.84 (d, 1 H, He, JHH = 6 Hz), 8.41 (d, 1 H, He, JHH = 6
3
3
MHz, d6-dmso): δ 177.4 (C7), 165.1 (Cc), 151.4 (C6), 141.2 (C1),
131.8 (C5), 131.5 (C4), 126.3 (C2), 125.2 (C3), 124.1 (Cb), 123.8
(Ce), 122.3 (Ca), 121.4 (Cd), 35.8 (CMe3), 29.9 (CMe3), 26.6 (Me).
IR (cm−1): ν(NH), 3301; ν(CO), 1607. ΛM (Ω−1·cm2·mol−1): not
soluble in acetone. Anal. Calcd for C27H34F3N3O5PdS: C, 47.97; H,
5.07; N, 6.22; S, 4.74. Found: C, 48.11; H, 4.90; N, 6.03; S, 4.76.
Synthesis of [{Pd(tBubpy)}2L6]TfO (L6 = μ-C,N,C,O-{C6H3C-
(O)NR}-2-(CO)-6, R = Me (6a), Tol (6b)]. A solution of the
appropriate complex 4 (4a·H2O, 500.0 mg, 0.48 mmol; 4b·H2O, 105.0
mg, 0.09 mmol) in CH2Cl2 (15 mL) was stirred under a CO
atmosphere for 1 or 2 h, respectively. The suspension was filtered
through Celite, the yellow solution was concentrated to 1 mL, and
Et2O (25 mL) was added. The suspension was filtered, and the solid
was washed with Et2O (3 × 5 mL) and dried, first by suction and then
under vacuum at 55 °C for 10 h to give a yellow (6a·H2O) or orange
(6b·H2O) powder.
Hz), 8.12 (d, 1 H, Hb, JHH = 2 Hz), 8.02 (d, 1 H, Hb, JHH = 2 Hz),
7.95 (d, 1 H, Hb, 4JHH = 2 Hz), 7.93 (br, 2 H, Hb+d), 7.64 (d, 1 H, Hd,
3JHH = 6 Hz), 7.51 (dd, 1 H, Hd, 3JHH = 6 Hz, 4JHH = 2 Hz), 7.42 (dd, 1
H, Hd, 3JHH = 6 Hz), 6.92 (m, 2 H, H3+5), 6.76 (br, t, 1 H, H4), 3.84 (s,
3 H, OMe), 3.78 (s, 3 H, OMe), 3.45 (s, 3 H, Me), 1.69 (s, 2 H, H2O),
1.43 (s, 9 H, CMe3), 1.42 (s, 9 H, CMe3), 1.38 (s, 9 H, CMe3), 1.37 (s,
9 H, CMe3). 13C{1H} APT NMR (100 MHz, CDCl3): δ 182.2 (C7),
172.2 (CO2), 165.5 (Cc), 164.9 (Cc), 164.7 (Cc + CO2), 163.9 (Cc),
156.2 (Ca), 156.0 (Ca+9), 155.0 (Ce), 154.7 (Ca), 153.2 (Ca), 152.1
(C6), 151.9 (Ce), 149.9 (Ce), 147.6 (Ce), 141.0 (C1), 135.2 (C8),
131.5 (C2), 131.3 (C3 or 5), 128.3 (C3 or 5), 127.5 (C4), 124.5 (Cd),
124.4 (Cd), 124.1 (Cd), 123.9 (Cd), 120.9 (Cb), 119.6 (Cb), 119.3
(Cb), 118.7 (Cb), 52.1 (OMe), 52.0 (OMe), 37.1 (Me), 35.8−35.7
(CMe3), 30.4 (CMe3), 30.3 (CMe3), 30.2 (CMe3), 30.1 (CMe3). IR
(cm−1): ν(CO, CO2Me), 1722; ν(CO), 1615. ΛM (Ω−1·cm2·mol−1):
4
4
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131.2. Anal. Calcd for C51H62F3N5O9Pd2S: C, 51.43; H, 5.25; N, 5.88;
S, 2.69. Found: C, 51.32; H, 5.06; N, 6.05; S, 2.43.
119.1 (Cb), 118.8 (Cb), 118.2 (Cb), 35.8 (CMe3), 35.6 (CMe3), 35.5
(CMe3), 30.3 (CMe3), 30.2 (CMe3), 30.1 (CMe3), 21.3 (Me, Tol),
19.8 (Me, Xy). IR (cm−1): ν(CO), 1613. ΛM (Ω−1·cm2·mol−1): 133.4.
Anal. Calcd for C60H71F3N6O6Pd2S: C, 56.56; H, 5.62; N, 6.60; S,
2.52. Found: C, 56.36; H, 5.80; N, 6.50; S, 2.22.
7b·2H2O: Yield: 102.0 mg, 88%. Mp: 214 °C (dec). 1H NMR (300
MHz, CDCl3): δ 9.09 (d, 1 H, He, 3JHH = 6 Hz), 8.91 (d, 1 H, He, 3JHH
4
4
= 6 Hz), 8.05 (d, 1 H, Hb, JHH = 2 Hz), 8.02 (d, 1 H, Hb, JHH = 2
Hz), 7.92 (br, 2 H, Hb), 7.77 (dd, 1 H, Hd, 3JHH = 6 Hz, 4JHH = 2 Hz),
Synthesis of [Pd(L9)(tBubpy)] (L9 = C,N-{C6H3C(O)NTol}-2-
{CHCHC(O)Me}-6 (9b)). To a solution of 4b·H2O (100.0 mg, 0.09
mmol) in CH2Cl2 (15 mL) was added MeC(O)CHCH2 (14.6 μL,
0.18 mmol). The reaction mixture was stirred for 2 h and filtered
through a short pad of MgSO4. The solution was concentrated to 1
mL and Et2O (25 mL) was added. The suspension was filtered, and
the solid was recrystallized from CH2Cl2/pentane (1:25 mL) and
suction dried to give 9b·1.5H2O as a yellow powder. Yield: 26 mg,
43%. Mp: 193 °C (dec). 1H NMR (300 MHz, CDCl3): δ 9.61 (d, 1 H,
7.73 (d, 1 H, He, 3JHH = 6 Hz), 7.41 (dd, 1 H, Hd, 3JHH = 6 Hz, 4JHH
=
2 Hz), 7.30 (d, 2 H, Tol, 3JHH = 8 Hz), 7.26−7.13 (m, 7 H, 2 CH, Tol,
2 Hd, H3+54+5), 6.90 (d, 1 H, He, JHH = 6 Hz), 3.81 (s, 3 H, OMe),
3
3.71 (s, 3 H, OMe), 2.45 (s, 3 H, Me, Tol), 1.58 (s, 4 H, H2O), 1.47
(s, 9 H, CMe3), 1.38 (s, 27 H, CMe3). 13C{1H} APT NMR (75 MHz,
CDCl3): δ 181.7 (C7), 172.4 (CO2), 165.4 (Cc), 165.0 (Cc), 164.9
(Cc), 164.3 (Cc), 164.1 (CO2), 156.8 (C9), 156.3 (Ca), 156.0 (Ca),
154.9 (Ce), 154.7 (Ca), 153.1 (Ca), 152.6 (Ce), 150.6 (C6), 149.0 (Ce),
147.9 (Ce), 143.8 (i-C, Tol), 140.1 (C1), 136.9 (C8), 135.9 (p-C, Tol),
131.2 (C3 or 5), 131.0 (C2), 129.1 (C3 or 5), 128.7 (C4), 124.6 (Cd),
123.9 (Cd), 123.4 (Cd), 123.0 (Cd), 120.0 (Cb), 119.4 (Cb), 119.0
(Cb), 118.8 (Cb), 52.0 (OMe), 35.8 (CMe3), 35.7 (CMe3), 35.6
(CMe3), 35.5 (CMe3), 30.2 (CMe3), 30.1 (CMe3), 21.2 (Me, Tol). IR
(cm−1): ν(CO, CO2Me), 1702; ν(CO), 1615. ΛM (Ω−1·cm2·mol−1):
130. Anal. Calcd for C57H68F3N5O10Pd2S: C, 53.27; H, 5.33; N, 5.45;
S, 2.50. Found: C, 53.36; H, 5.26; N, 5.45; S, 2.30.
3
3
H9, JHH = 17 Hz), 9.03 (d, 1 H, He, JHH = 6 Hz), 7.94 (d, 1 H, Hb,
4JHH = 2 Hz), 7.93 (d, 1 H, Hb, 4JHH = 2 Hz), 7.61 (dd, 1 H, Hd, 3JHH
=
6 Hz, 4JHH = 2 Hz), 7.38 (m, 3 H, Tol + H5, 3JHH = 8 Hz), 7.29 (d, 1
H, H3, 3JHH = 8 Hz), 7.18 (d, 2 H, Tol, 3JHH = 8 Hz), 7.12 (t, 1 H, H4,
3JHH = 8 Hz), 7.07 (dd, 1 H, Hd, 3JHH = 6 Hz, 4JHH = 2 Hz), 6.62 (d, 1
H, He, JHH = 6 Hz), 6.51 (d, 1 H, H8, JHH = 17 Hz), 2.44 (s, 3 H,
Me), 2.37 (s, 3 H, Me, Tol), 1.57 (s, 3 H, H2O), 1.47 (s, 9 H, CMe3),
1.36 (s, 9 H, CMe3). 13C{1H} APT NMR (75 MHz, CDCl3): δ 201.3
(CO), 179.6 (C7), 163.6 (Cc), 163.3 (Cc), 156.3 (Ca), 154.6 (Ca),
152.1 (Ce), 151.4 (C6), 149.7 (Ce), 146.1 (i-C, Tol), 144.5 (C9), 141.5
(C1), 134.5 (C2), 134.1 (p-C, Tol), 132.9 (C3), 129.7 (m-C, Tol),
128.9 (C8), 128.2 (o-C, Tol), 127.7 (C4), 123.6 (Cd), 123.4 (C5),
122.7 (Cd), 119.2 (Cb), 118.1 (Cb), 35.6 (CMe3), 35.3 (CMe3), 30.3
(CMe3), 25.9 (Me), 21.2 (Me, Tol). IR (cm−1): ν(CO), 1665, 1615.
Anal. Calcd for C36H42N3O3.5Pd: C, 63.67; H, 6.23; N, 6.19. Found: C,
63.47; H, 6.18; N, 6.23.
3
3
Synthesis of [{Pd(tBubpy)}2L8]TfO (L8 = C,N,C,O-{C6H3C(O)-
NR}-2-(CNXy)-6, R = Me (8a), Tol (8b)). To a solution of the
appropriate complex 4 (4a·H2O: 250.0 mg, 0.24 mmol; 4b·H2O:
216.0 mg, 0.19 mmol) in CH2Cl2 (20 mL) was added XyNC (for 8a:
31.8 mg, 0.24 mmol; for 8b: 25.6 mg, 0.19 mmol). The reaction
mixture was stirred for 30 min or 1 h, respectively, and filtered through
Celite, and the solution was concentrated to 1 mL. Et2O (for 8a, 25
mL) or n-hexane (for 8b, 25 mL) was added; the suspension was
filtered. The solid was washed with Et2O (8a, 2 × 5 mL) or n-hexane
(8b, 2 × 5 mL) and suction dried to give 8a·H2O or 8b·2H2O as an
orange powder.
Synthesis of [{Pd2(tBubpy)(CNXy)2}L6]TfO (L6 = μ-C,N,C,O-
{C6H3C(O)NMe}-2-(CO)-6 (10a)). To a solution of 6a·H2O (125.0
mg, 0.12 mmol) in CH2Cl2 (20 mL) was added XyNC (31 mg, 0.24
mmol). The reaction mixture was stirred for 30 min and filtered
through Celite. The solution was concentrated to 1 mL, Et2O (25 mL)
was added, and the suspension was filtered. The solid was washed with
Et2O (3 × 5 mL) and suction dried to give 10a·H2O as a yellow
1
8a·H2O: Yield: 200.0 mg, 71%. Mp: 210 °C (dec). H NMR (400
3
MHz, CDCl3): δ 8.96 (m, 2 H, He, JHH = 6 Hz), 8.76 (d, 1 H, He,
3JHH = 6 Hz), 8.16 (d, 1 H, Hb, 4JHH = 2 Hz), 8.13 (d, 1 H, Hb, 4JHH
=
2 Hz), 7.92 (d, 1 H, Hb, 4JHH = 2 Hz), 7.84 (d, 1 H, Hb, 4JHH = 2 Hz),
7.81 (dd, 1 H, Hd, 3JHH = 6 Hz, 4JHH = 2 Hz), 7.78 (dd, 1 H, Hd, 3JHH
1
=
powder. Yield: 104.0 mg, 81%. Mp: 213 °C (dec). H NMR (400
6 Hz, 4JHH = 2 Hz), 7.64 (dd, 1 H, Hd, 3JHH = 6 Hz, 4JHH = 2 Hz), 7.18
(d, 2 H, H3+5, 3JHH = 7 Hz), 7.12 (t, 1 H, H4, 3JHH = 7 Hz), 6.88 (d, 2
H, m-CH, Xy, 3JHH = 7 Hz), 6.69 (t, 1 H, p-CH, Xy, 3JHH = 7 Hz), 3.56
(s, 3 H, Me), 2.57 (br, 6 H, Me, Xy), 1.58 (s, 2 H, H2O), 1.49 (s, 18 H,
CMe3), 1.44 (s, 9 H, CMe3), 1.36 (s, 9 H, CMe3). 13C{1H} APT NMR
(75 MHz, CDCl3): δ 179.2 (C7), 164.8 (Cc), 163.8 (Cc), 156.5 (Ca),
155.2 (Ca), 154.6 (Ca), 152.6 (Ca), 152.5 (Ce), 152.0 (Ce), 151.7 (C6),
150.1 (Ce), 147.9 (o-C, Xy), 147.5 (Ce), 142.8 (C1), 138.3 (C=NXy),
132.3 (C3), 130.3 (C4), 128.1 (m-C, Xy), 127.3 (i-C, Xy), 124.4 (Cd),
124.2 (Cd), 124.1 (Cd), 124.0 (Cd), 122.7 (p-C, Xy), 122.2 (C5), 120.0
(Cb), 119.4 (Cb), 118.7 (Cb), 118.2 (Cb), 36.8 (Me), 35.7 (CMe3),
35.5 (CMe3), 30.4 (CMe3), 30.3 (CMe3), 30.1 (CMe3), 19.9 (Me, Xy).
IR (cm−1): ν(CO), 1612. ΛM (Ω−1·cm2·mol−1): 121. Anal. Calcd for
C54H65F3N6O5Pd2S: C, 54.96; H, 5.55; N, 7.12; S, 2.72. Found: C,
54.62; H, 5.39; N, 7.01; S, 3.06.
MHz, CDCl3): δ 9.05 (d, 1 H, He, 3JHH = 6 Hz), 8.81 (d, 1 H, He, 3JHH
= 6 Hz), 8.05 (br, 2 H, Hb), 7.81 (d, br, 1 H, Hd, 3JHH = 6 Hz), 7.61 (d,
br, 1 H, Hd, 3JHH = 6 Hz), 7.54 (d, 1 H, H3, 3JHH = 7 Hz), 7.37 (m, 4
3
H, H5 + CH, Xy), 7.24 (m, 3 H, CH, Xy), 7.14 (t, 1 H, H4, JHH = 7
Hz), 3.67 (s, 3 H, Me), 2.53 (s, 6 H, Me, Xy), 7.51 (s, 6 H, Me, Xy),
1.59 (s, 2 H, H2O), 1.46 (s, 18 H, CMe3). 13C{1H} APT NMR (100
MHz, CDCl3): 217.8 (CO), 177.1 (C7), 165.2 (Cc), 164.5 (Cc),
155.2 (Ca), 153.9 (C6), 152.7 (Ca), 150.2 (Ce), 147.5 (Ce), 143.2 (C1),
140.4 (C3), 135.8 (o-C, Xy), 135.6 (o-C, Xy), 133.5 (C2), 131.5 (C4),
131.1 (p-C, Xy), 130.9 (p-C, Xy), 128.4 (m-C, Xy), 128.1 (m-C, Xy),
124.1 (Cd), 123.4 (Cd), 122.5 (C5), 119.1 (Cb), 118.3 (Cb), 40.2
(Me), 35.7 (CMe3), 35.6 (CMe3), 30.4 (CMe3), 30.3 (CMe3), 18.8
(Me, Xy). IR (cm−1): ν(CN), 2170; ν(CO), 1643, 1612. ΛM
(Ω−1·cm2·mol−1): 134.2. Anal. Calcd for C46H50F3N5O6Pd2S: C,
51.60; H, 4.71; N, 6.54; S, 2.99. Found: C, 51.92; H, 4.56; N, 6.89; S,
2.60.
8b·2H2O: Yield: 223.0 mg, 92%. Mp: 216 °C (dec). 1H NMR (300
MHz, CDCl3): δ 9.02 (d, 1 H, He, 3JHH = 6 Hz), 8.12 (d, 1 H, Hb, 4JHH
= 2 Hz), 8.10 (d, 1 H, Hb, 4JHH = 2 Hz), 7.87 (s, br, 1 H, Hb), 7.82 (s,
br, 1 H, Hb), 7.70 (dd, 1 H, Hd, 3JHH = 6 Hz, 4JHH = 2 Hz), 7.66 (d, 1
H, He, 3JHH = 6 Hz), 7.43 (d, 2 H, o-CH, Tol, 3JHH = 8 Hz), 7.36 (d, 2
H, m-CH, Tol, 3JHH = 8 Hz), 7.28 (d, 1 H, H3, 3JHH = 8 Hz), 7.23 (d, 1
H, H5, 3JHH = 8 Hz), 7.19−7.12 (m, 4 H, 2 Hd, He, H4), 6.88 (d, 2 H,
m-CH, Xy, 3JHH = 8 Hz), 6.77 (d, 1 H, He, 3JHH = 6 Hz), 6.69 (t, 1 H,
Synthesis of [{Pd(tBubpy)}2L10]TfO (L10 = μ-C,N,C,O-{C6H3C-
(O)NTol}(CO)-2-{C(CO2Me)C(CO2Me)}-6 (11b)). A solution
containing 7b·2H2O (72.0 mg, 0.06 mmol) in CH2Cl2 (15 mL) was
stirred under a CO atmosphere for 6 h. The resulting suspension was
filtered through Celite, the solution was concentrated to 1 mL, and
Et2O (25 mL) was added. The suspension was filtered, and the solid
was washed with Et2O (3 × 5 mL) and suction dried to give 11b·H2O
as a yellow powder. Yield: 42.0 mg, 58%. Mp: 226 °C (dec). 1H NMR
3
p-CH, Xy, JHH = 8 Hz), 2.55 (s, 9 H, Me, Xy, Tol), 1.58 (s, 4 H,
3
H2O), 1.49 (s, 9 H, CMe3), 1.40 (s, 9 H, CMe3), 1.39 (s, 9 H, CMe3),
1.35 (s, 9 H, CMe3). 13C{1H} APT NMR (75 MHz, CDCl3): δ 178.7
(C7), 165.0 (Cc), 164.6 (Cc), 164.5 (Cc), 163.9 (Cc), 156.5 (Ca), 155.0
(Ca), 154.7 (Ca), 152.6 (Ca), 152.3 (Ce), 152.0 (Ce), 151.9 (C6), 149.1
(Ce), 148.0 (o-C, Xy), 147.0 (Ce), 143.9 (i-C, Tol), 142.2 (C1), 139.0
(C=NXy), 135.7 (p-C, Tol), 132.6 (C3), 131.2 (C4), 129.7 (m-C, Tol),
128.1 (m-C, Xy), 127.1 (i-C, Xy), 126.9 (o-C, Tol), 124.1 (Cd), 123.1
(Cd), 123.0 (Cd), 122.7 (p-C, Xy), 122.2 (Cd), 121.7 (C5), 120.2 (Cb),
(300 MHz, CDCl3): δ 8.89 (d, 4 H, He, JHH = 6 Hz), 8.81 (d, 1 H,
H5, 3JHH = 8 Hz), 8.12 (s, 4 H, Hb), 7.70 (m, 5 H, 4 Hd + H3), 7.61 (t,
1 H, H4, 3JHH = 8 Hz), 7.19 (d, 2 H, o-CH, Tol, 3JHH = 8 Hz), 6.98 (d,
3
2 H, m-CH, Tol, JHH = 8 Hz), 3.88 (s, 3 H, OMe), 3.66 (s, 3 H,
OMe), 2.27 (s, 3 H, Me, Tol), 1.58 (s, 2 H, H2O), 1.44 (s, 36 H,
CMe3). 13C{1H} APT NMR (75 MHz, CDCl3): δ 213.6 (CO),
173.5 (CO2), 166.8 (C7), 164.9 (Cc), 163.4 (CO2), 154.2 (Ca), 148.5
(Ce), 145.3 (C9), 140.1 (C8), 138.3 (C6), 137.9 (p-C, Tol), 136.2
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Article
(C5), 134.3 (C4), 132.2 (C2), 129.7 (C1), 129.4 (o-C, Tol), 128.7 (i-C,
Tol), 125.9 (m-C, Tol), 123.8 (Cd), 123.2 (C3), 118.8 (Cb), 52.5
(OMe), 52.4 (OMe), 35.6 (CMe3), 30.3 (CMe3), 21.2 (Me, Tol).
13C{1H} APT NMR of complex 11 prepared using 13CO (100 MHz,
CDCl3): δ 213.6 (CO), 173.5 (CO2), 166.8 (C7), 164.9 (Cc), 163.4
(CO2), 154.2 (Ca), 148.5 (Ce), 145.3 (C9), 140.1 (C8), 138.3 (d, C6,
3JCC = 5 Hz), 137.9 (p-C, Tol), 136.2 (C5), 134.2 (d, C4, 3JCC = 5 Hz),
itself, or twinning (although all reflections seemed to be well indexed),
or residual absorption errors. A variety of data reduction and
absorption correction options were used, but the peak remained.
ASSOCIATED CONTENT
■
S
* Supporting Information
CIF files for compound 6b·0.36H2O. This material is available
132.2 (d, C2, JCC = 64 Hz), 129.7 (d, C1, JCC = 3 Hz), 129.4 (o-C,
Tol), 128.7 (i-C, Tol), 125.9 (m-C, Tol), 123.8 (Cd), 123.2 (d, C3,
2JCC = 3 Hz), 118.8 (Cb), 52.5 (OMe), 52.4 (OMe), 35.6 (CMe3), 30.3
(CMe3), 21.2 (Me, Tol). IR (cm−1): ν(CO), 1819 (the sample
prepared with 13CO shows this band at 1778 cm−1); νassym(CO2),
1721, 1709; ν(COPd), 1615. ΛM (Ω−1·cm2·mol−1): 129.5. Anal.
Calcd for C58H66F3N5O10Pd2S: C, 53.79; H, 5.14; N, 5.41; S, 2.48.
Found: C, 53.50; H, 4.98; N, 5.29; S, 2.40.
1
2
free of charge via the Internet at http://pubs.acs.org.
AUTHOR INFORMATION
Corresponding Author
*E-mail: jvs1@um.es. Web: www:http://www.um.es/gqo/.
■
Notes
The authors declare no competing financial interest.
X-ray Crystallography. Numerical details of crystal data, data
collection, and refinement are summarized in Table 1. The data for
ACKNOWLEDGMENTS
We thank the Spanish Ministerio de Ciencia e Innovacion
(grant CTQ2007-60808/BQU, with FEDER support) and
Fundacion Seneca (grants 02992/PI/05 and 04539/GERM/
́ ́
06) for financial support and I.V.-H. for a grant.
■
́
Table 1. Crystal Data and Structure Refinement of Complex
6b·0.36H2O
parameters
remarks
6b·0.36H2O
complex
formula
fw
REFERENCES
C52H58.72F3N5O5.36Pd2S
1141.38
■
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