Synthesis and reactivity of palladium(II) fluoride complexes containing nitrogen-donor ligands

Article abstract of DOI:10.1039/b914426a

This article describes the synthesis, characterization, and reactivity of palladium(II) fluoride complexes containing sp² and sp³ nitrogen-containing supporting ligands. Both cis and trans complexes of general structure (N)(N′)Pd^II(R)(F) (R = Ar or CH₃) as well as cis-(N)₂Pd^II(F)₂ are reported. Crystallographic characterization of these molecules has allowed structural comparisons to related phosphine-ligated species. Furthermore, these studies have revealed that nitrogen-donor ligands support some of the longest and the shortest Pd-F bonds reported to date. The thermal decomposition of (N)(N′)Pd^II(R)(F) has also been examined, and no products of C-F bond-forming reductive elimination were obtained in any case. The Royal Society of Chemistry.

Full text of DOI:10.1039/b914426a

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www.rsc.org/dalton | Dalton Transactions
Synthesis and reactivity of palladium(II) fluoride complexes containing
nitrogen-donor ligands†
Nicholas D. Ball, Jeff W. Kampf and Melanie S. Sanford*
Received 17th July 2009, Accepted 30th September 2009
First published as an Advance Article on the web 26th November 2009
DOI: 10.1039/b914426a
This article describes the synthesis, characterization, and reactivity of palladium(II) fluoride complexes
containing sp2 and sp3 nitrogen-containing supporting ligands. Both cis and trans complexes of general
structure (N)(N¢)PdII(R)(F) (R = Ar or CH3) as well as cis-(N)2PdII(F)2 are reported. Crystallographic
characterization of these molecules has allowed structural comparisons to related phosphine-ligated
species. Furthermore, these studies have revealed that nitrogen-donor ligands support some of the
longest and the shortest Pd–F bonds reported to date. The thermal decomposition of (N)(N¢)PdII(R)(F)
has also been examined, and no products of C–F bond-forming reductive elimination were obtained in
any case.
remain rare.7 Early reports suggested that phosphines might
be essential to stabilize the M–F bond; however, very recent
Introduction
communications by our group2i and by Grushin8 have shown
that sp2 nitrogen-donors can also support stable PdII(Ar)(F)
species. Such adducts could be valuable intermediates for C–F
bond-forming transformations, since competing P–F coupling
is clearly not possible in these systems. Herein, we report the
synthesis, characterization, and reactivity of a series of aryl and
alkyl palladium fluorides containing both sp2 and sp3 nitrogen
donor ligands. X-ray crystallographic characterization of many
of these complexes has allowed structural comparisons to related
phosphine-containing species. In addition, the thermal decompo-
sition of the new compounds has been investigated.
Organopalladium complexes containing fluoride ligands are of
significant current interest due to their potential intermediacy in
both C–F activation and C–F bond-forming transformations.1,2
Grushin and coworkers published the first example of an isolable
aryl palladium fluoride complex, trans-(PPh3)2PdII(Ph)(F), in
1997.3 Following this seminal report, a variety of related com-
pounds bearing phosphine supporting ligands have been prepared
and characterized.2-5 The thermal decomposition of all of these
complexes has been studied in detail, with the ultimate goal of
achieving C–F bond-forming reductive elimination to generate
aryl fluorides. However, this transformation has proven chal-
lenging, as P–F bond-formation typically predominates over the
desired C–F coupling in these PdII phosphine complexes.4,6
Results and discussion
In contrast to the extensive literature on PdII(R)(F) phosphine
complexes, palladium fluorides bearing nitrogen-donor ligands
Our general synthetic approach to the palladium(II) fluoride
complexes described herein involved reaction of the corresponding
PdII iodides with AgF, using a procedure very similar to that
developed by Grushin.2a The palladium(II) iodide precursors,
in turn, were prepared using three different synthetic strategies
that are summarized in Scheme 1. The cyclometalated C–N
complexes 2–5 were generated by reaction of the readily available
Department of Chemistry, University of Michigan, 930 N. University Ave.,
Ann Arbor, Michigan, USA. E-mail: mssanfor@umich.edu; Fax: +1 734-
647-4865; Tel: +1 734-615-0451
† Electronic supplementary information (ESI) available: Full details of the
crystallographic data for compounds 8, 10–13, and 15. CCDC reference
numbers 733308–733309 & 741019–741022. For ESI and crystallographic
data in CIF or other electronic format see DOI: 10.1039/b914426a
9
cyclopalladated dimers [(phpy)Pd(I)]2 (1a) and [(bzq)Pd(I)]2
Scheme 1 Synthesis of palladium(II) iodide complexes 2–7.
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©

(1b) (phpy = 2-phenylpyridine; bzq = benzo[h]quinoline) with
2,6-lutidine, 4-tert-butylpyridine (tBu-py), or PPh3, respectively.
Complex 6 was accessed by reaction of the known pincer
complex (NCN)Pd(Br)10 (NCN = N,N,N¢,N¢-tetramethyl-1,3-
xylylenediamine) with NaI. Finally, 7 was prepared by reaction of
(tBu-bpy)Pd(Me)2 (tBu-bpy = 4,4¢-di-tert-butylbipyridine) with
11
MeI.
Synthesis of (phpy)Pd(lutidine)(F), 8 and (phpy)Pd(tBu-py)(F), 9
The 2-phenylpyridine complexes 8 and 9 were prepared by
sonication of 2 and 3 with AgF in benzene under an N2 atmosphere
for 5 h at 25 ◦C. The products were isolated by filtration through
R
Celiteꢀ and recrystallization from CH2Cl2/pentanes to afford 8 as
a yellow solid (47%) and 9 as a white solid (45%). Analysis of 8 and
9 by 19F NMR spectroscopy revealed characteristic PdII fluoride
resonances as broad singlets at -260.3 ppm and -243.4 ppm,
respectively. The 1H NMR spectrum of 8 shows signals indicative
of an unsymmetrical square planar complex, with Ha and Hb of
the 2-phenylpyridine ligand appearing as doublets at 8.70 and
5.77 ppm, respectively. Similar diagnostic upfield and downfield
Fig. 1 X-ray crystal structure of 8. Thermal ellipsoids are drawn
at 50% probability, hydrogen atoms are omitted for clarity. Selected
˚
bond lengths (A): Pd1-C11 1.960(3), Pd1-N1 2.017(2), Pd1-N2 2.055(2),
Pd1-F1 2.1024(17). Selected bond angles (◦): C11-Pd1-N1 82.13(11),
C11-Pd1-N2 93.68(10), N1-Pd1-N2 175.36(9), C11-Pd1-F1 173.88(9),
N1-Pd1-F1 92.32(8), N2-Pd1-F1 91.95(8).
1
peaks were observed in the H NMR spectrum of 9 at 8.96 (Ha)
1
and 6.50 ppm (Hb). Notably, the H NMR resonances for Ha in
8 and 9 appear approximately 1 ppm upfield from those in the
corresponding palladium(II) iodides 2 and 3 (9.89 and 9.91 ppm,
respectively). Literature precedent suggests that this large Dd is
indicative of a cis orientation between the fluoride ligand and the
pyridine nitrogen of the phpy (Scheme 2).9
Scheme 3 Synthesis of complexes 10 and 11.
indicating an unsymmetrical square planar complex, with Ha and
Hb of the benzo[h]quinoline ligand appearing as doublets at 9.03
and 5.95 ppm, respectively. Similar to 8 and 9, the chemical shift
of Ha in 10 is nearly 1 ppm upfield from that of the corresponding
Pd iodide (4), indicative of a cis orientation of the fluoride and
bzq nitrogen ligands.
Scheme 2 Synthesis of complexes 8 and 9.
It is particularly notable that both 3 and 9 are stable, isolable
complexes that do not undergo loss of the 4-tert-butylpyridine
ligand (with concomitant generation of halide bridged Pd dimers)
upon work up. In contrast, previous reports have suggested that
alkyl/aryl substituents at the 2- and/or 6-positions of the pyridine
ligand are frequently necessary to limit formation of halide bridged
dimers in related systems.9
Recrystallization of 8 by slow diffusion of pentanes into a THF
solution at -35 ◦C afforded colorless needles suitable for X-ray
crystallographic analysis. The X-ray structure of 8 is shown in
Fig. 1, and it confirms the predicted cis configuration of the phpy
nitrogen atom and the fluoride ligand. Interestingly, the Pd–F
Slow diffusion of pentanes into a CH2Cl2 solution of 10 in
CH2Cl2 at -35 ◦C provided yellow blocks of this complex. An
X-ray crystal structure was obtained, and the structure of 10
is shown in Fig. 2. As predicted on the basis of the NMR
spectral data, this complex contains cis fluoride and bzq nitrogen
substituents. Notably, the sole difference between complexes 8
and 10 is the nature of the cyclometalated ligand. In the 2-
phenylpyridine complex 8, this ligand is slightly twisted out of
the square plane with a C11-C6-C5-N1 dihedral angle of 6.16◦.
In contrast, the more rigid benzo[h]quinoline13 of 10 is essentially
planar (the C11-C12-C13-N1 dihedral angle in 10 is 0.75◦). The
increased rigidity of 10 may account for the significantly shorter
˚
bond distance of 2.1024(17) A in 8 is the longest reported for
an isolable monomeric PdII(Ar)(F) complex. The next closest is
˚
˚
(by 0.042 A) Pd–F bond (2.0604(12) A) and significantly longer
3,12
˚
˚
˚
(by 0.017 A) Pd–C bond (1.9769(19) A) in this complex relative to
2.085(3) A in trans-(PPh3)2Pd(Ph)(F).
those in 8.
Synthesis of (bzq)Pd(lutidine)(F), 10
Synthesis of (bzq)Pd(PPh3)(F), 11
Compound 10 was prepared as a yellow solid (57% yield) using an
analogous procedure to the synthesis of 8 and 9 (Scheme 3). Its 19
F
Compound 11 was isolated as a pale yellow solid in 84% yield from
the reaction of 5 with AgF (Scheme 3). In this case, the fluoride
ligand appears as an apparent singlet at -247.2 ppm by 19F NMR
NMR spectrum contains a broad singlet at -270.4 ppm for the Pd-
bound fluoride ligand. The 1H NMR spectrum of 10 shows signals
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©

cis PPh3 and s-arylbzq groups. Correspondingly, the Pd–F bond of
˚
11 was shorter (by 0.030 A) in 11 versus 10.
Synthesis of (NCN)Pd(F), 12
Pincer complex 12 was synthesized in 63% yield using an analo-
gous procedure to that for 8–11. Complex 12 is the first example
of an isolable palladium fluoride containing sp3 nitrogen donor
ligands.14 This molecule shows a broad singlet at -243.7 ppm for
the Pd–F bond by 19F NMR spectroscopy.
Colorless crystals of 12 were generated by slow diffusion of
◦
pentanes in a CH2Cl2 solution of this compound at -35 C. An
X-ray crystal structure was obtained and is shown in Fig. 4.
˚
Intriguingly, the Pd–F bond distance in 12 of 2.0959(7) A is
comparable to that in complex 8.12 The other metric parameters
(for example, the Pd–N and Pd–C bond lengths) are very similar
to those in related (NCN)Pd–Cl species.15
Fig. 2 X-ray crystal structure of 10. Thermal ellipsoids are drawn at
50% probability, hydrogen atoms and CH2Cl2 are omitted for clarity.
˚
Selected bond lengths (A): Pd1-C11 1.9769(19), Pd1-N1 2.0325(15),
Pd(1)-N(2) 2.0519(15), Pd1-F1 2.0604(12). Selected bond angles (◦):
C11-Pd1-N1 82.89(7), C11-Pd1-N2 92.46(7), N1-Pd1-N2 174.46(6),
C11-Pd1-F1 174.14(6), N1-Pd1-F1 91.29(6), N2-Pd1-F1 93.32(5).
spectroscopy. In addition, the 31P NMR spectrum of 11 shows a
corresponding broad doublet at 40.7 ppm. The 31P/19F coupling
constant (JPF = 8 Hz) is similar to that observed for other cis
fluoride and phosphine ligands at PdII centers.2a,3,16
X-ray quality crystals of 11 were obtai◦ned by slow diffusion of
pentanes into a CH2Cl2 solution at -35 C, and the structure of
11 is shown in Fig. 3. Compound 11 is unique in that it is the first
example of a PdII aryl fluoride containing both P- and N-donor
ligands. Replacing the 2,6-lutidine of 10 with a PPh3 in 11 leads
˚
˚
to a 0.027 A increase in the Pd–Cbzq bond length to 2.004(2) A.
This may be due to unfavourable steric interactions between the
Fig. 4 X-ray crystal structure of 12. Thermal ellipsoids are drawn at 50%
probability, hydrogen atoms and CH2Cl2 are omitted for clarity. Selected
bond lengths Pd1-C7 1.9068(11), Pd1-N1 2.0954(9), Pd(1)-N(2) 2.1019(9),
Pd1-F1 2.0959(7). Selected bond angles (◦): C7-Pd1-N1 81.69(4),
C7-Pd1-N2 81.61(4), N1-Pd1-N2 163.27(4), C7-Pd1-F1 176.62(4),
N1-Pd1-F1 96.89(3), N2-Pd1-F1 99.74(3).
Synthesis of (tBu-bpy)Pd(4-FC6H4)(F), 13
Complex 13 was prepared by reaction of (tBu-bpy)Pd(p-FC6H4)(I)
with AgF as previously reported in the literature (Scheme 4).2i The
19F NMR spectrum of 13 shows two resonances—a broad singlet
at -340.7 ppm for the Pd–F and a multiplet at -122.9 ppm for the
Ar–F.
Fig. 3 X-ray crystal structure of 11. Thermal ellipsoids are drawn at
50% probability, hydrogen atoms and CH2Cl2 are omitted for clarity.
Two polymorphs were present (only one is shown, see ESI† for more
˚
information). Selected bond lengths (A): Pd1-C11 2.004(2), Pd1-F1
2.0301(15), Pd1-N1 2.0762(19), Pd1-P1 2.2458(6). Selected bond angles
(◦): C11-Pd1-F1 169.77(8), C11-Pd1-N1 82.52(9), F1-Pd1-N1 87.36(7),
C11-Pd1-P1 96.97(7), F1-Pd1-P1 93.23(5), N2-Pd1-P1 176.20(6).
Scheme 4 Synthesis of complexes 13–15.
634 | Dalton Trans., 2010, 39, 632–640
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Crystallization of 13 was achieved by diffusion of pentanes into
a fluorobenzene solution of the complex at -35 ◦C. This afforded
yellow blade-like crystals, and the structure of 13 is shown in
Fig. 5. This X-ray structure confirms the square planar geometry
of 13 as well as the cis orientation of the p-F phenyl and fluoride
ligands. Complex 13 is a rare example of a monomeric Pd–F
compound with the F trans to an L-type ligand.6,16 Notably, the
Analysis by 19F NMR spectroscopy revealed a broad singlet at
-354.06 ppm corresponding to Pd–F. The H NMR spectrum
1
shows signals indicative of a symmetrical square planar complex
with the protons at the 6-position of the tBu-bpy ligand appearing
at 8.51 ppm.
Complex 15 was crystallized by vapor diffusion of pentanes into
an acetone solution of the compound at -35 ◦C to afford colorless
blocks for X-ray crystallographic analysis. The X-ray structure of
this complex is shown in Fig. 6.
˚
˚
Pd–F bond in 13 (1.999(4) A) is significantly (0.078 A) shorter
than that in the closely related trans-configured complexes trans-
t
˚
(py)2Pd(Ph)(F) and trans-( Bu-py)2Pd(Ph)(F) (Pd–F = 2.077(4) A
˚
and 2.079(2) A, respectively). Indeed, 13 contains the shortest
known Pd–F bond for a monomeric PdII(Ar)(F) complex,12
with the closest being in trans-(iPr3P)2Pd(F)(4-C5F4N) (Pd–F =
1e
˚
2.0158(16) A). Interestingly, the Pd–C bond distance in 13 of
˚
1.981(8) A is nearly identical to that in trans-(py)2Pd(Ph)(F) and
trans-( Bu-py)2Pd(Ph)(F) (1.982(3) and 1.978(2) A, respectively).
t
8
˚
Fig. 6 X-ray crystal structure of 15. Thermal ellipsoids are drawn at 50%
probability, hydrogen atoms and CH2Cl2 are omitted for clarity. Selected
˚
bond lengths (A): Pd1-F1 1.9708(11), Pd1-N1 1.9722(15). Selected bond
angles (◦): F1-Pd1-F1A 91.70(7), F1-Pd1-N1A 174.52(6), F1A-Pd1-N1A
93.64(6), F1-Pd1-N1 93.64(6), F1A-Pd1-N1 174.52(6), N1A-Pd1-N1
81.04(9). Symmetry transformations used to generate equivalent atoms:
#1-x+3/2,-y+1/2,z #2-x+1/2,-y+1/2,z.
Fig. 5 X-ray crystal structure of 13. Thermal ellipsoids are drawn at
50% probability, hydrogen atoms and CH2Cl2 are omitted for clarity. The
structure was solved as two identical structures in a unit cell (only one is
˚
shown, see ESI† for more information). Selected bond lengths (A): Pd1-C1
Intriguingly, the observed Pd–F length in 15 (1.9708(11))
is very similar to those in trans-(tBu-py)2Pd(F)2 (1.947(4) and
1.958(4) A), which contains the shortest Pd–F bonds ever observed
1.981(8), Pd1-F1 1.999(4), Pd1-N2 2.026(6), Pd1-N1 2.086(7). Selected
bond angles (◦): C1-Pd1-F1 89.9(3), C1-Pd1-N2 96.6(3), F1-Pd1-N2
173.5(2), C1-Pd1-N1 174.3(3), F1-Pd1-N1 93.8(2), N2-Pd1-N1 79.7(3).
˚
in a molecular Pd fluoride complex.8 In the case of trans-
(tBu-py)2Pd(F)2, Grushin and Marshall reasonably argued that
the short Pd–F distances resulted from field/inductive effects
associated with the two trans fluoride ligands. They suggested
that these ligands increased the ionic character of the PdII–F
interaction and thereby enhanced electrostatic contributions to the
bonding.8 The observation of nearly identical Pd–F bond lengths
in the cis complex 15 suggests that a trans orientation of the two
fluoride ligands is not essential to see a similar structural effect.17
A comparison of the Pd–F bond length in 15 to that for other
complexes reported herein (as well as selected examples from the
literature) is shown in Fig. 7 and 8.
Synthesis of (tBu-bpy)Pd(CH3)(F), 14
Compound 14 was synthesized in 69% yield similarly to 8–13 by
sonication of palladium iodide 7 with AgF in benzene (Scheme 4).
19F NMR spectroscopy shows a resonance for the fluorine bound
1
to palladium as a broad singlet at -347.4 ppm. The H NMR
spectrum shows the methyl ligand as a doublet at 0.84 ppm with
JHF = 6 Hz. The 13C NMR signal for the Me group appears as a
doublet at 0.0039 ppm with JCF = 1.3 Hz. Notably 14 is the first
example of an alkyl PdII–F containing N-donor ligands.2a
Synthesis of (tBu-bpy)Pd(F)2, 15
Thermolysis of aryl PdII fluorides
Compound 15 was accessed by stirring PdII diiodide 7 and AgF in
Palladium fluorides 8–14 are potential intermediates in C–F bond-
CH2Cl2 according to a previously reported procedure (Scheme 4).2i
forming reactions.2 Thus, a final set of experiments was conducted
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Dalton Trans., 2010, 39, 632–640 | 635
©

Fig. 7 Comparison of Pd–F bond lengths of selected literature PdII–F compounds (grey) and compounds (8, 13, 15, white). Error bars demonstrate
three standard deviations (95% confidence level) in the error of the bond lengths.
Fig. 8 Comparison of Pd–F bond lengths of literature PdII–F compounds (grey) and the new complexes 8, 10–13, and 15 (white).
636 | Dalton Trans., 2010, 39, 632–640
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©

to study the thermal decomposition of these complexes. Heating
compounds 8–14 in nitrobenzene at 150 ◦C for 16 h resulted
in the precipitation of palladium black, indicating that the Pd
centers were reduced from PdII to Pd0. However, analysis of the
crude reaction mixtures by gas chromatography and 19F NMR
spectroscopy showed that no products of C–F bond-forming
reductive elimination were formed. Instead, the major organic
products were biaryls resulting from coupling between two of the
s-aryl ligands. This process likely proceeds via well-precedented
Ar transfer between Pd centers, followed by C–C bond-forming
reductive elimination.2i,8,18 Notably, these results are similar to
those reported by Grushin for the thermal decomposition of trans-
(tBu-py)2Pd(Ph)(F).8
column. Sonication was performed using a VWR Model 75H7
ultrasound bath, with the temperature regulated by a Neslab RTE-
111 recirculating chiller.
Materials and reagents
The palladium complexes Pd(dba)2,21 (NCN)PdBr,10 (tBu-
bpy)PdMe2,11 [(phpy)Pd(OAc)]2,22 [(bzq)Pd(OAc)]2,23 (bzq)2,24
(phpy)2,24 and (4,4¢-difluoro-1,1¢-biphenyl)25 were prepared ac-
cording to literature procedures. Palladium fluorides (tBu-
bpy)Pd(p-FC6H4)(F) and (tBu-bpy)PdF2 were prepared accord-
ing to previously reported procedures.2i AgF and 1-fluoro-4-
t
iodobenzene were obtained from Matrix Chemicals. MeI, Bu-
t
bpy, 2,6-lutidine, and LiI were obtained from Aldrich. Bu-py
was obtained from TCI America. PPh3 was obtained from Strem
Chemicals. All reagents were used as received. Nitrobenzene-d5,
CD2Cl2, and CDCl3 were obtained from Cambridge Isotope Lab-
oratories. All other solvents were obtained from Fisher Chemical.
Dichloromethane and pentane were purified using an Innovative
Technologies (IT) solvent purification system consisting of a
copper catalyst, activated alumina, and molecular sieves. Benzene
was distilled from Na0/benzophenone and stored over activated
Conclusions
In summary, this report described the synthesis, characterization,
and reactivity a series of PdII–F complexes containing sp2 and
sp3 nitrogen donor ligands. We have disclosed the first examples
of isolable PdII fluorides containing (a) sp3 nitrogen ligands, (b)
both s-alkyl and nitrogen ligands, and (c) both phosphorus and
nitrogen ligands. Structural analysis of these compounds by X-
ray crystallography has revealed both the longest (complex 8) and
shortest (complex 13) Pd–F bonds reported to date for monomeric
PdII aryl fluorides. In addition, we report the intriguing finding that
cis-(tBu-bpy)Pd(F)2 has Pd–F bond distances within the error of
the related complex trans-(tBu-py)2Pd(F)2. Finally, thermolysis of
all of these new complexes was shown to result in C–C rather than
C–F bond-forming reactions. These results further highlight the
challenges associated with achieving C–F bond forming reductive
elimination from PdII centers.
˚
4 A molecular sieves. Acetone was distilled from CaSO4. All
syntheses were conducted using standard Schlenk techniques or
in an inert atmosphere glovebox unless otherwise noted.
Preparations
[(phpy)Pd(I)]2 (1a). In air, [(phpy)Pd(OAc)]2 (1.5 g, 2.2 mmol,
1 equiv) was weighed into a 250 mL Erlenmeyer flask and dissolved
in acetone (100 mL). In a separate flask, LiI (1.2 g, 8.8 mmol) was
dissolved in water (50 mL). The LiI solution was added slowly
to the stirring solution of [(phpy)Pd(OAc)]2, and the resulting
mixture was stirred at room temperature overnight. The reaction
mixture was filtered, and the solid obtained was washed with a 1 : 1
solution of MeOH–H2O (3 ¥ 10 mL) followed by a 1 : 1 mixture
of hexanes–Et2O (3 ¥ 3 mL). The resulting material was dried in
vacuo, yielding the product (1a) as a yellow solid (1.7 g, 95% yield).
Spectroscopic data for this complex matched that reported in the
literature.9
Experimental section
General
NMR spectra were obtained on a Varian Inova 400 (399.96 MHz
1
for H; 376.34 MHz for 19F; 100.57 MHz for 13C) or a MR400
(400.53 MHz for H: 376.87 MHz for 19F; 100.71 MHz for 13C)
1
spectrometer. 1H, 19F and 13C chemical shifts are reported in parts
per million (ppm) relative to TMS, with the residual solvent peak
used as an internal reference. 19F NMR spectra are referenced on
a unified scale, where the single primary reference is the frequency
[(bzq)Pd(I)]2 (1b). Complex 1b was synthesized via an analo-
gous procedure to the preparation of 1a, with [(bzq)Pd(OAc)]2
(1.5 g, 2.2 mmol) as the starting material. The product was
obtained as a dark yellow solid (1.6 g, 88% yield). 1H NMR (95%
CDCl3, 5% C5D5N): d 9.87 (br s, 2H), 8.17 (d, J = 8 Hz, 2H),
7.65 (d, J = 9 Hz, 2H), 7.52 (d, J = 9 Hz, 4H), 7.54 (m, 2H),
7.21 (d, J = 8 Hz, 2H), 6.14 (br s, 2H); 13C NMR (CDCl3, 1
drop of C5D5N): d 154.84, 149.34, 141.34, 136.95, 135.43, 133.42,
128.62, 128.42, 126.84, 123.50, 123.11, 121.72 (two aromatic 13C
resonances appear to be coincidentally overlapping). (Found: C,
38.07, H, 1.93, N, 3.50. C22H16I2N2Pd2 requires 37.94, H, 1.96, N,
3.40).
of the residual solvent peak in the H NMR spectrum.19 Several
1
19F NMR experiments were conducted using “No-D” parameters
and are noted accordingly.20 1H and 19F multiplicities are reported
as follows: singlet (s), broad singlet (br s), doublet (d), doublet of
doublets (dd), triplet (t), and multiplet (m). Elemental analyses
were conducted by Atlantic Microlabs in Norcross, Georgia.
Microanalysis for many of the Pd–F complexes described herein
was consistently low in C. This is believed to result from the
hygroscopic nature of these materials because of the possibility of
strong H-bonding interactions between the Pd–F and H2O.2a,2i The
amount of water could not be accurately quantified by 1H NMR
analysis due to broadening of the signal via rapid exchange. Full
1H,19F and 13C NMR spectra are provided for each of these Pd–F
compounds in the ESI.† Gas chromatographs were obtained on a
(phpy)Pd(lutidine)(I), 2. Complex 2 was prepared under am-
bient conditions using a modification of the literature procedure.9
To a stirring suspension of dimer 1a (0.50 g, 0.65 mmol, 1 equiv)
in acetone (16 mL) was added 2,6-lutidine (0.30 mL, 4 equiv)
dropwise. The resulting clear solution was stirred for 15 min.
The solvent was then removed under vacuum, and the resulting
solid was recrystallized from CH2Cl2–hexanes and dried in vacuo
R
Shimadzu 17A using a Restek Rtxꢀ-5 (crossbond 5% diphenyl
polysiloxane, 15 m, 0.25 mm ID, 0.25 mm ID, 0.25 mm df)
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The Royal Society of Chemistry 2010
Dalton Trans., 2010, 39, 632–640 | 637
©

yielding 2 as a yellow solid (0.53 g, 83% yield). 1H NMR (CDCl3):
d 9.89 (d, J = 5 Hz, 1H), 7.79 (t, J = 8 Hz, 1H), 7.66 (multiple
peaks, 2H), 7.43 (d, J = 8 Hz, 1H), 7.22 (multiple peaks, 2H), 7.10
(multiple peaks, 2H), 6.85 (t, J = 8 Hz, 1H), 5.58 (d, J = 6 Hz,
1H), 3.12 (s, 6H). 13C NMR (CDCl3): d 165.07, 159.79, 156.94,
154.03, 145.92, 138.29, 130.25, 129.65, 124.97, 123.37, 123.02,
122.83, 118.48, 28.57 (two aromatic 13C resonances appear to be
coincidentally overlapping). (Found: C, 43.44, H, 3.31, N, 5.88.
C18H17IN2Pd requires C, 43.70, H, 3.36, N, 5.63).
and the product was further purified by recrystallization from
CH2Cl2–hexanes. The product was obtained as a microcrystalline
yellow solid (0.71 g, 90% yield). 1H NMR (CDCl3): d 6.97 (t, J =
8 Hz, 1H), 6.74 (d, J = 8 Hz, 2H), 3.98 (s, 4H), 2.99 (s, 12H);
13C NMR (CDCl3): d 159.19, 145.15, 124.60, 119.75, 73.94, 54.84.
(Found C, 33.95, H, 4.34, N, 6.59. C12H19IN2Pd requires C, 33.94,
H, 4.51, N, 6.60).
(tBu-bpy)Pd(Me)(I), 7. In the glovebox, (t-Bu-bpy)PdMe2
(0.77 g, 3.1 mmol, 1.9 equiv) was weighed into a 20 mL
scintillation vial and dissolved in acetone (2 mL). MeI was added
dropwise to this solution. The reaction was stirred for 30 min,
during which time it changed from a clear yellow solution to
a cloudy suspension. Pentanes (8 mL) was added to completely
precipitate the product, and the solids were collected, and washed
with pentanes (3 ¥ 2 mL). The resulting material was dried
in vacuo to yield 7 as a yellow solid. Further purification by
recrystallization from CH2Cl2/hexanes afforded analytically pure
compound (0.86 g, 52% yield). 1H NMR (CDCl3): d 9.29 (d, J =
6 Hz, 1H), 8.46 (d, J = 6 Hz, 1H), 8.08 (d, J = 2 Hz, 1H), 8.02 (d,
J = 2 Hz, 1H), 7.59 (dd, J = 6, 2 Hz, 1H), 7.44 (dd, J = 6, 2 Hz,
1H), 1.45 (s, 9H), 1.42 (s, 9H), 0.738 (s, 3H). 13C NMR (CDCl3):
d 163.93, 163.27, 157.29, 154.01, 152.21, 146.93, 124.39, 123.94,
120.09, 118.98, 36.01, 35.87, 30.63, 30.57, 7.63. (Found C, 44.19,
H, 5.31, N, 5.61. C19H27IN2Pd requires C, 44.16, H, 5.27, N, 5.42).
(phpy)Pd(tBu-py)(I), 3. Complex 3 was prepared via an analo-
gous procedure to the preparation of 2, using 1a (1.0 g, 1.3 mmol, 1
equiv) and tBu-py (1.5 mL, 5.1 mmol, 4 equiv) as starting materials.
The product was obtained as a pale yellow solid (0.93 g, 69% yield).
1H NMR (CDCl3): d 9.91 (d, J = 5 Hz, 1H), 8.80 (d, J = 6 Hz,
2H), 7.76 (m, 1H), 7.64 (d, J = 8 Hz, 1H), 7.43-7.39 (multiple
peaks, 3H), 7.10-7.07 (multiple peaks, 2H), 6.92 (m, 1H), 5.87
(d, J = 8 Hz, 1H), 1.34 (s, 9H). 13C NMR (CDCl3): d 165.24,
162.67, 157.36, 155.96, 153.02, 145.88, 138.37, 131.28, 129.47,
125.05, 123.42, 122.71, 118.55, 35.22, 30.32 (two aromatic 13C
resonances appear to be coincidentally overlapping). (Found: C,
45.65, H, 4.15, N, 5.26. C22H21IN2Pd requires C, 45.95, H, 4.05,
N, 5.36).
(bzq)Pd(lutidine)(I), 4. Complex 4 was prepared via an anal-
ogous procedure to the preparation of 2, using 1b (0.50 g,
0.61 mmol, 1 equiv) and 2,6-lutidine (0.30 mL, 4.5 equiv) as
starting materials. The product was obtained as a yellow solid
(phpy)Pd(lutidine)(F), 8. In the glovebox, 2 (0.66 g 1.3 mmol,
1 equiv) and AgF (0.66 g, 5.2 mmol, 3.9 equiv) were weighed into
an amber glass jar. Benzene (27 mL) was added, and the reaction
was sonicated for 5 h. Under N2, the resulting mixture was then
1
(0.52 g, 82% yield). H NMR (CDCl3): d 10.1 (d, J = 6 Hz,
1H), 8.27 (d, J = 8 Hz, 1H), 7.73-7.68 (multiple peaks, 2H), 7.62-
7.56 (multiple peaks, 2H), 7.47 (m, 1H), 7.28-7.19 (multiple peaks,
3H), 5.81 (d, J = 8 Hz, 1H), 3.12 (s, 6H). 13C NMR (CDCl3):
d 160.09, 155.39, 155.19, 152.63, 141.59, 138.32, 136.92, 133.54,
128.64, 128.58, 127.33, 126.96, 123.71, 123.12, 123.03, 122.11,
28.67. (Found: C, 45.48, H, 3.16, N, 5.40. C20H17IN2Pd requires
C, 46.31, H, 3.30, N, 5.40).
R
filtered through Celiteꢀ and washed with CH2Cl2 (3 ¥ 5 mL). This
filtration was repeated, and then the solvent removed in vacuo. The
resulting solid was recrystallized from CH2Cl2–pentanes, and the
1
product was obtained as a yellow solid (0.23 g, 47% yield). H
NMR (CDCl3): d 8.70 (br d, J = 6 Hz 1H), 7.72 (t, J = 8 Hz,
1H), 7.58-7.52 (multiple peaks, 2H), 7.32 (d, J = 8 Hz, 1H), 7.13-
7.08 (multiple peaks, 3H), 6.93 (m, 1H), 6.70 (m, 1H), 5.77 (d,
J = 8 Hz, 1H), 3.13 (s, 6H). 19F NMR (CDCl3): d -260.3 (br s,
1F). 13C NMR (CDCl3): d 164.55, 160.11, 149.35, 145.72, 138.71,
138.31, 133.12, 129.19, 128.12, 124.07, 123.09, 122.76, 121.80,
117.80, 27.76. (Found C, 53.40, H, 4.66, N, 6.61. C18H17FN2Pd
requires C, 55.90, H, 4.43, N, 7.24%).
(bzq)Pd(PPh3)(I), 5. Complex 5 was prepared via an anal-
ogous procedure to the preparation of 4, using 1b (0.50 g,
0.61 mmol, 1 equiv) and PPh3 (0.72 g, 2.7 mmol, 4.5 equiv) as
starting materials. The product was obtained as a yellow solid
1
(0.53 g, 65% yield). H NMR (CDCl3): d 10.46 (br s, 1H), 8.27
(d, J = 8 Hz, 1H), 7.87-7.83 (multiple peaks, 6H), 7.70 (m, 1H),
7.60 (m, 1H), 7.50 (m, 1H), 7.45-7.40 (multiple peaks, 4H), 7.36-
7.33 (multiple peaks, 6H), 6.87 (t, J = 8 Hz, 1H), 6.65 (t, J =
8 Hz, 1H). 31P NMR (CDCl3): d 44.67 (1P). 13C NMR (CDCl3):
d 155.41, 155.18, 154.46, 143.06, 137.19, 135.82, 135.63 (d, J =
12 Hz), 133.92, 133.43 (d, J = 52 Hz), 130.74, 129.07, 128.01 (d,
J = 11 Hz), 127.87, 127.17, 123.42, 123.31, 122.12 (d, J = 3 Hz).
(Found C, 55.01, H, 3.39, N, 2.14. C31H23INPPd requires C, 55.26,
H, 3.44, N, 2.08).
(phpy)Pd(tBu-py)(F), 9. Complex 9 was prepared via an anal-
ogous procedure to the preparation of 8, using 3 (0.60 g, 1.2 mmol,
1 equiv), AgF (0.57 g, 4.5 mmol, 3.9 equiv), and benzene (23 mL)
as starting materials and conducting the sonication for 3 h. The
1
product was obtained as a white solid (0.22 g, 45% yield). H
NMR (CDCl3): d 8.96 (d, J = 5 Hz, 1H), 8.82 (d, J = 6 Hz,
2H), 7.82 (m, 1H), 7.62 (d, J = 8 Hz, 1H), 7.44-7.41 (multiple
peaks, 3H), 7.17 (m, 1H), 7.06 (m, 1H), 6.94 (m, 1H), 6.50 (d,
J = 8 Hz, 1H), 1.34 (s, 9H); 19F NMR (CD2Cl2): d -243.4; 13C
NMR (CD2Cl2): d 164.71, 162.80, 152.06, 149.56, 145.98, 138.73,
133.76, 129.10, 128.21, 124.19, 123.17, 122.45, 121.69, 117.83,
35.08, 30.18. (Found : C, 57.95, H, 5.01, N, 6.67. C20H21FN2Pd
requires C, 57.91, H, 5.10, N, 6.75).
(NCN)Pd(I), 6. In air, (NCN)PdBr (2.0 g, 3.1 mmol, 1.0 equiv)
was weighed into a 250 mL Erlenmeyer flask and dissolved in
acetone (141 mL). In a separate 100 mL Erlenmeyer flask, LiI
(1.7 g, 13 mmol, 4 equiv) was dissolved in water (71 mL). The
aqueous LiI solution was added slowly to the stirring solution of
(NCN)PdBr in acetone, and the resulting solution was stirred at
23 ◦C for an additional 12 h. The reaction mixture was then filtered
through a frit, and the resulting solid washed with water (3 ¥ 5 mL)
and diethyl ether (3 ¥ 5 mL). The solvent was removed in vacuo,
(bzq)Pd(lutidine)(F), 10. Complex 10 was prepared via an
analogous procedure to the preparation of 8, using 4 (0.40 g,
0.77 mmol, 1 equiv) and AgF (0.38 g, 3.0 mmol, 3.9 equiv) as
starting materials and conducting the sonication for 5 h. The
638 | Dalton Trans., 2010, 39, 632–640
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The Royal Society of Chemistry 2010
©

1
1
product was obtained as a yellow solid (0.18 g, 57% yield). H
affording the product (8) as a white solid (0.24 g, 63% yield). H
NMR (CDCl3): d 9.03 (br d, J = 5 Hz, 1H), 8.19 (d, J = 8 Hz,
1H), 7.62-7.59 (multiple peaks, 2H), 7.50 (d, J = 8 Hz, 1H), 7.46-
7.40 (multiple peaks, 2H), 7.17 (d, J = 8 Hz, 2H), 7.05 (d, J =
8 Hz, 1H), 5.95 (d, J = 8 Hz, 1H), 3.20 (s, 6H). 19F NMR (CDCl3):
d -270.4. 13C NMR (CDCl3): d 160.52, 154.66, 148.40, 141.58,
138.45, 137.04, 133.15, 130.19, 128.69, 128.38, 128.27, 126.31,
123.31, 122.88, 122.29, 121.15, 27.99. (Found: C 54.76; H, 4.53
N, 6.35. C20H17FN2Pd requires 58.48; H, 4.17 N, 6.82).
NMR (CD2Cl2): d 6.90 (t, J = 8 Hz, 1H), 6.72 (d, J = 8 Hz, 2H),
3.95 (s, 4H), 2.84 (s, 12H). 19F NMR (CD2Cl2): d -243.7 (br s,
1F). 13C NMR (CD2Cl2): d 145.76, 129.48, 124.14, 119.97, 74.57,
52.28. (Found : C, 42.55, H, 6.30, N, 8.04. C12H19FN2Pd requires
C, 45.51, H, 6.05, N, 8.85).
(tBu-bpy)Pd(Me)(F), 14. Complex 14 was prepared via an
analogous procedure to the preparation of 8, using 7 (0.40 g,
0.77 mmol, 1 equiv) and AgF (0.38 g, 3.0 mmol, 3.9 equiv) as
starting materials and conducting the sonication for 3 h. The
(bzq)Pd(PPh3)(F), 11. Complex 11 was prepared via an analo-
gous procedure to the preparation of 8, using 5 (0.40 g, 0.59 mmol,
1 equiv) and AgF (0.29 g, 2.3 mmol, 3.9 equiv) as starting materials
and conducting the sonication for 5 h. The product was obtained
1
product was obtained as a yellow solid (0.22 g, 69% yield). H
NMR (CDCl3): d 8.69 (d, J = 6 Hz, 1H), 8.48 (d, J = 6 Hz,
1H), 7.98 (s, 1H), 7.97 (s, 1H), 7.59 (dd, J = 5 Hz, 2 Hz, 1H),
7.42 (dd, J = 6 Hz, 2 Hz, 1H), 1.43 (s, 9H), 0.84 (d, J = 6 Hz,
3H). 19F NMR (CDCl3): d -347.4 (br s, 1F). 13C NMR (CDCl3):
d 163.96, 163.37, 157.75, 152.92, 150.75, 148.08, 124.15, 124.02,
119.77, 118.32, 36.01, 35.92, 30.72, 30.49, 0.039 (d, J = 1.3 Hz).
(Found: C, 54.04, H, 6.65, N, 6.56. C19H27FN2Pd requires C, 55.82,
H, 6.66, N, 6.85).
1
as a white solid (0.28 g, 84% yield). H NMR (CDCl3): d 9.30
(m, 1H), 8.29 (d, J = 8 Hz, 1H), 7.82-7.77 (multiple peaks, 6H),
7.70 (d, J = 9 Hz, 1H), 7.60 (d, J = 8 Hz, 1H), 7.55 (m, 1H)
7.47-7.42 (multiple peaks, 4H), 7.39-7.34 (multiple peaks, 6H),
7.33 (s, C6H6, 6H), 6.79 (t, J = 8 Hz 1H), 6.54 (m, 1H). 19F NMR
(CDCl3): d -247.2 (apparent s, 1F). 31P NMR (CDCl3): d 40.7 (d,
J = 8 Hz, 1P). 13C NMR (CDCl3): d 153.34, 147.37, 147.31, 142.94,
137.52, 135.37 (d, J = 12 Hz), 133.67, 130.85, 130.82, 129.91 (d,
J = 50 Hz), 129.04, 128.32 (C6H6), 128.23 (d, J = 8 Hz), 128.07,
126.46, 123.09, 122.64, 121.16 (J = 4 Hz). (Found: C, 68.43, H,
4.47, N, 2.38. C31H23FNPPd·C6H6 requires C, 69.00, H, 4.54, N,
2.95).
General procedure for the thermolysis of compounds 8–13. In
the glovebox, each Pd–F (10 mg) was weighed into a 4 mL
scintillation vial and dissolved in nitrobenzene-d5 to generate a
0.03 M solution. The vials were sealed with TeflonTM-lined caps,
and the reactions were stirred at 150 ◦C for 16 h. The reactions were
cooled to room temperature, 4-fluoronitrobenzene was added as an
internal standard, and the distribution of products was analyzed
by 19F NMR spectroscopy and gas chromatography.
(NCN)Pd(F), 12. In the glovebox, 6 (0.50 g, 1.2 mmol, 1 equiv)
and AgF (0.59 g, 4.6 mmol, 3.9 equiv) were dissolved in benzene
(23 mL) in a 50 mL amber glass jar. The jar was sealed with a
TeflonTM-lined cap, and the reaction was sonicated in the dark at
25 ◦C for 3 h. The resulting suspension was filtered through a plug
Crystallographic data. X-ray diffraction data were collected
with a Bruker SMART APEX CCD-based X-ray diffractometer
equipped with a low-temperature device and fine focus Mo-
target X-ray tube. The structures were solved and refined with
the Bruker SHELXTL (version 6.12) software package.26 The
crystallographic data, details of data collection and refinement,
R
of Celiteꢀ in the drybox. The plug was washed with benzene (1 ¥
5 mL) and then with CH2Cl2 (5 ¥ 2 mL). The solvent was removed
under reduced pressure. The solid was collected and dried in vacuo
Table 1 Crystallographic data, details of data collection and refinement for 8, 10–13, and 15
8
10a
11a
12c
13b
15a
Molecular Formula
M
C18H17FN2Pd
386.74
Monoclinic
C21H19Cl2FN2Pd C32H25Cl2FNPPd C13H21Cl2FN2Pd C57H65F4N4Pd2
C19H26Cl2F2N2Pd
497.72
Orthorhombic
495.68
Monoclinic
P21/c
650.80
Triclinic
¯
P1
401.62
Triclinic
¯
P1
1094.93
Monoclinic
Ia
Crystal system
Space group
(standard setting)
P21/c
Pccn
˚
a/A
9.6607(11)
9.2742(10)
17.810(2)
13.904(4)
11.409(3)
14.366(4)
8.7399(5)
17.2959(9)
20.3468 (11)
96.861(1)
98.293(1)
104.123(1)
2913.0(3)
4, 1.484
8.4407(6)
9.5451(6)
11.5693(8)
105.314(1)
95.629(1)
116.010(1)
782.97(9)
2, 1.704
17.9592(12)
17.5332(12)
20.2950(14)
11.1616(9)
11.9919(9)
15.6096(10)
˚
b/A
˚
c/A
a/◦
b/◦
g /◦
96.023(2)
117.158(3)
95.135(1)
90
3
˚
V/A
1586.9(3)
2027.8(9)
4, 1.624
1.195
6364.9(8)
4, 1.143
0.610
2089.3(3)
4, 1.582
1.166
Z, calculated density/Mg m-3 4, 1.619
Absorption coefficient/mm-1 1.177
0.904
1.525
Crystal size/mm
T/K
Reflections collected
Independent reflections (Rint
Data/parameters
wR2 (obs. and all data)
R1 (obs. and all data)
0.33 ¥ 0.14 ¥ 0.07 0.34 ¥ 0.20 ¥ 0.16 0.25 ¥ 0.24 ¥ 0.05 0.32 ¥ 0.30 ¥ 0.22 0.25 ¥ 0.10 ¥ 0.09 0.10 ¥ 0.10 ¥ 0.10
85
108
85
85
85
85
39833
4339 (0.0578)
4339/211
44848
5037 (0.0379)
5037/246
128348
14487 (0.0328)
14487/79
38567
4384 (0.0282)
4084/176
70232
11189 (0.0652)
11189/682
92957
6735 (0.0631)
6735/128
)
0.0797 and 0.0842 0.0508 and 0.0551 0.0934 and 0.0961 0.0386 and 0.0387 0.1553 and 0.1651 0.1032 and 0.1102
0.0323 and 0.0383 0.0214 and 0.0307 0.0367 and 0.0403 0.0147 and 0.0150 0.0552 and 0.0700 0.0386 and 0.0507
a Crystal structure contains an equivalent of CH2Cl2. b There are two independent palladium complexes in the asymmetric unit, ref. 1e. c There are two
independent palladium complexes and two equivalents of CH2Cl2 in the asymmetric unit.
This journal is
The Royal Society of Chemistry 2010
Dalton Trans., 2010, 39, 632–640 | 639
©

for the X-ray structures reported herein is summarized in Table 1.
Structures 8 and 15 were twinned. The twin domains were related
by a 4.2◦ rotation about the direct (0.900 0.100 1) axis or reciprocal
(0.048 0.031 1) axis and a refined twin volume fraction of 0.281(1)
for 8. Structure 15 twin domains were refined by a 180◦ rotation
about the direct (1 1 0) axis and a refined twin volume fraction
of 0.886(2). Further experimental details as well as full tables of
bond distances and bond angles are included for structures 8,
10–12 and, 15 in the ESI.† Full experimental details for 13 were
previously reported by our group (see ref. 2i). In addition, Pd–F
bond distances from all reported monomeric Pd–F complexes are
shown in Fig. 8.27
4 (a) W. J. Marshall, D. L. Thorn and V. V. Grushin, Organometallics,
1998, 17, 5427–5430; (b) V. V. Grushin, Organometallics, 2000, 19, 1888–
1900; (c) V. V. Grushin, Chem.–Eur. J., 2002, 8, 1006–1014; (d) V. V.
Grushin and W. J. Marshall, J. Am. Chem. Soc., 2006, 128, 12644–
12645.
5 (a) There are also several examples of organopalladium fluorides of
which the Pd–F bond is a part of a Lewis acid/base complex (e.g., Pd–
FBF3 or Pd–FHF). See: A. L. Rheingold, G. Z. Wu and R. F. Heck,
Inorg. Chim. Acta, 1987, 131, 147–150; (b) D. C. Roe, W. J. Marshall,
F. Davidson, P. D. Soper and V. V. Grushin, Organometallics, 2000, 19,
4575–4582.
6 P–F bond formation predominates upon thermolysis of both trans
and cis-PdII aryl fluorides: W. J. Marshall and V. V. Grushin,
Organometallics, 2003, 22, 555–562.
7 V. V. Grushin and W. J. Marshall, Organometallics, 2008, 27, 4825–4828.
8 V. V. Grushin and W. J. Marshall, J. Am. Chem. Soc., 2009, 131, 918–
919.
Abbreviations
9 D. S. Black, G. B. Deacon and G. L. Edwards, Aust. J. Chem., 1994,
47, 217–227.
dba
= dibenzylidene acetone
= N,N,N¢,N¢-tetramethyl-1,3-xylylenediamine
= 4,4¢-di-tert-butyl-2,2¢-bipyridine
= 2-phenylpyridine
10 P. L. Alsters, P. J. Baesjou, M. D. Janssen, H. Kooijman, A. Sicherer-
Roetman, A. L. Spek and G. Van Koten, Organometallics, 1992, 11,
4124–4135.
11 G. Liu and R. J. Puddephatt, Inorg. Chim. Acta, 1996, 251, 319–323.
12 Determined by computing the bond length 3 standard deviations; 95%
confidence level.
NCN
tBu-bpy
phpy
bzq
= benzo[h]quinoline
p-FPh
= 4-fluorophenyl
13 J. M. Racowski, A. R. Dick and M. S. Sanford, J. Am. Chem. Soc.,
tBu-py
= 4-tert-butylpyridine
2009, 131, 10974.
14 (NH3)2PdF2 has been implicated but not fully characterized. H.
Mu¨eller, Liebigs Ann. Chem., 1853, 86, 341–368.
15 M. Q. Slagt, G. Rodr´ıguez, M. M. P. Grutters, R. J. M. Klein Gebbink,
W. Klopper, L. W. Jenneskens, M. Lutz, A. L. Spek and G. van Koten,
Chem.–Eur. J., 2004, 10, 1331–1344.
Acknowledgements
We thank the NIH NIGMS (R01-GM073836 and F31-
GM089141) and the Research Corporation Cottrell Scholar
Program for support of this research. We also thank Matthew
Remy for experimental assistance in the preparation of 7.
16 (a) This is a rare example of a monomeric PdII(Ar)(F) monomer with the
fluoride trans to an L-type ligand. However, there are several examples
of this orientation in PdII(F)2 complexes and PdII fluoride bridged
dimers. See: A. Yahav, I. Goldberg and A. Vigalok, J. Am. Chem. Soc.,
2003, 125, 13634–13635; (b) A. W. Kaspi, A. Yahav-Levi, I. Goldberg
and A. Vigalok, Inorg. Chem., 2008, 47, 5–7; (c) V. V. Grushin and
W. J. Marshall, Angew. Chem., Int. Ed., 2002, 41, 4476–4479; (d) V. V.
Grushin and W. J. Marshall, Organometallics, 2007, 26, 4997–5002.
17 The molecular orbital basis for the observed short Pd–F bonds in 15
is not fully understood and may be different from that leading to the
similar structural features in trans-(tBu-py)2Pd(F)2.
Notes and references
1 (a) For reviews and examples, see: M. Hudlicky, J. Fluorine Chem., 1989,
44, 345–359; (b) N. M. Doherty and N. W. Hoffman, Chem. Rev., 1991,
91, 553; (c) J. L. Kiplinger, T. G. Richmond and C. E. Osterberg, Chem.
Rev., 1994, 94, 373–431; (d) E. F. Murphy, R. Murugavel and H. W.
Roesky, Chem. Rev., 1997, 97, 3425–3468; (e) N. A. Jasim, R. N. Perutz,
A. C. Whitwood, T. Braun, J. Izundu, B. Neumann, S. Rothfeld and
H. G. Stammler, Organometallics, 2004, 23, 6140–6149; (f) T. Braun,
A. Steffen, V. Schorlemer, B. Neumann and H. G. Stammler, Dalton
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640 | Dalton Trans., 2010, 39, 632–640
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