New pentafluorophenyl complexes with phosphine-amide ligands

Article abstract of DOI:10.1016/j.ica.2005.11.014

A series of nickel(II) and palladium(II) complexes containing one or two pentafluorophenyl ligands and the phosphino-amides o-Ph₂PC ₆H₄CONHR [R = ⁱPr (a), Ph (b)] displaying different coordination modes have been synthesised. The chelating ability of these ligands and the influence of both coligands and the metal centre in their potential hemilabile behaviour have been explored. The crystal structure of (b) has been determined and reveals N-H?O intermolecular hydrogen bonding. Bis-pentafluorophenyl derivatives [M(C₆F₅) ₂(o-Ph₂PC₆H₄CO-NHR)] [M = Ni; R = ⁱPr (1a); R = Ph (1b); M = Pd; R = ⁱPr (2a); R = Ph (2b)] in which (a) and (b) act as rigid P, O-chelating ligands were readily prepared from the labile precursors cis-[M(C₆F₅) ₂(PhCN)₂]. X-ray structures of (1a), (1b) and (2a) have been established, allowing an interesting comparative structural discussion. Dinuclear [{Pd(C₆F₅)(tht)(μ-Cl)}₂] reacted with (a) and (b) yielding the monopentafluorophenyl complexes [Pd(C ₆F₅)Cl{PPh₂(C₆H₄-CONH-R)} ] (R = ⁱPr (3a), Ph (3b)) that showed a P, O-chelating behaviour of the ligands, confirmed by the crystal structure determination of (3a). New cationic palladium(II) complexes in which (a) and (b) behave as P-monodentate ligands have been synthesised by reacting them with [{Pd(C₆F ₅)(tht)(μ-Cl)}₂], stoichiometric Ag(O ₃SCF₃) and external chelating reagents such as cod [Pd(C₆F₅)(cod){PPh₂(C₆H ₄-CONH-R)}](O₃SCF₃)(R = ⁱPr (4a), Ph (4b)) and 2,2′-bipy [Pd(C₆F₅)(bipy){PPh ₂(C₆H₄-CONH-R)}](O₃SCF₃) (R = ⁱPr (5a), Ph (5b)). When chloride abstraction in [{Pd(C ₆F₅)(tht)(μ-Cl)}₂] is promoted by means of a dithioanionic salt as dimethyl dithiophospate in the presence of (a) or (b), the corresponding neutral complexes [Pd(C₆F₅){S(S)P(OMe) ₂}{PPh₂(C₆H₄-CONH-R)}] (R = ⁱPr (6a), Ph (6b)) were obtained.

Full text of DOI:10.1016/j.ica.2005.11.014

Inorganica Chimica Acta 359 (2006) 1650–1658
www.elsevier.com/locate/ica
New pentafluorophenyl complexes with phosphine-amide ligands
a,
a
a
b
b
*
´
´
´
´
´
Gregorio Sanchez , Joaquın Garcıa , David Meseguer , Jose L. Serrano , Luis Garcıa ,
b
a
´ ´
´
Jose Perez , Gregorio Lopez
a
Departamento de Quı´mica Inorga´nica, Universidad de Murcia, 30071 Murcia, Spain
Departamento de Ingenierı´a Minera, Geolo´gica y Cartogra´fica, Area de Quı´mica Inorga´nica, 30203 Cartagena, Spain
b
Received 20 October 2005; accepted 20 November 2005
Available online 4 January 2006
Abstract
A series of nickel(II) and palladium(II) complexes containing one or two pentafluorophenyl ligands and the phosphino-amides
o-Ph2PC6H4CONHR [R = iPr (a), Ph (b)] displaying different coordination modes have been synthesised. The chelating ability of these
ligands and the influence of both coligands and the metal centre in their potential hemilabile behaviour have been explored. The crystal
structure of (b) has been determined and reveals N–Hꢀ ꢀ ꢀO intermolecular hydrogen bonding. Bis-pentafluorophenyl derivatives
[M(C6F5)2(o-Ph2PC6H4CO-NHR)] [M = Ni; R = iPr (1a); R = Ph (1b); M = Pd; R = iPr (2a); R = Ph (2b)] in which (a) and (b) act
as rigid P, O-chelating ligands were readily prepared from the labile precursors cis-[M(C6F5)2(PhCN)2]. X-ray structures of (1a), (1b)
and (2a) have been established, allowing an interesting comparative structural discussion. Dinuclear [{Pd(C6F5)(tht)(l-Cl)}2] reacted
with (a) and (b) yielding the monopentafluorophenyl complexes [Pd(C6F5)Cl{PPh2(C6H4–CONH–R)}] (R = iPr (3a), Ph (3b)) that
showed a P, O-chelating behaviour of the ligands, confirmed by the crystal structure determination of (3a). New cationic palladium(II)
complexes in which (a) and (b) behave as P-monodentate ligands have been synthesised by reacting them with [{Pd(C6F5)(tht)(l-Cl)}2],
stoichiometric Ag(O3SCF3) and external chelating reagents such as cod [Pd(C6F5)(cod){PPh2(C6H4-CONH-R)}](O3SCF3)(R = iPr (4a),
Ph (4b)) and 2,20-bipy [Pd(C6F5)(bipy){PPh2(C6H4-CONH-R)}](O3SCF3) (R = iPr (5a), Ph (5b)). When chloride abstraction in
[{Pd(C6F5)(tht)(l-Cl)}2] is promoted by means of a dithioanionic salt as dimethyl dithiophospate in the presence of (a) or (b), the cor-
responding neutral complexes [Pd(C6F5){S(S)P(OMe)2}{PPh2(C6H4-CONH-R)}] (R = iPr (6a), Ph (6b)) were obtained.
Ó 2005 Elsevier B.V. All rights reserved.
Keywords: Phosphino-amide ligands; Coordination modes; Pentafluorophenyl ligands; Nickel; Palladium
1. Introduction
It is in this last field that phosphine-amide ligands have
received growing attention: the asymmetric 1,4-addition
reaction of arylboronic acids with cycloalkenones is catal-
ysed by an amidophosphine rhodium(I) complex [12],
new chiral amidophosphine ligands take part in palla-
dium-catalysed asymmetric allylic alkylation processes
[13–15], amide derived phosphines possessing various
N,N-dialkyl aromatic amide scaffolds have shown to be
highly effective in Suzuki cross-coupling reactions [16,17],
and 2-diphenylphosphinobenzamido nickel complexes
have found application in ethylene polymerization, show-
ing that slight variations in the ligand frame produce dras-
tic changes in the catalytic behaviour [18].
Hybrid ligands that contain distinct chemical functions
[1–5], such as soft phosphine and hard (e.g., N or O) donor
atoms, have attracted continuous interest during the last
few years as a result of their versatile coordination behav-
iour [6,7] and their potential hemilability [3–5]. These
properties have been exploited in several ways, as the
‘‘weak-link approach’’ for the synthesis of supramolecular
structures [8] or the use of some ligands and their com-
plexes in chemical sensings [9–11] and catalytic processes.
*
In this sense, both ligands design and studies about the
conditions in which the different bonding patterns may take
Corresponding author.
E-mail address: gsg@um.es (G. Sanchez).
´
0020-1693/$ - see front matter Ó 2005 Elsevier B.V. All rights reserved.
doi:10.1016/j.ica.2005.11.014

G. Sa´nchez et al. / Inorganica Chimica Acta 359 (2006) 1650–1658
1651
place are of considerable importance to understand and
then to make use of the properties exhibited by ligands
and complexes [5]. Thus, the influence of coligands in the
hemilability of a given ligand, or the variations in its coor-
dination behaviour towards different metal centres would
contribute to a deeper knowledge of the ligand itself and
its usefulness. We have recently reported the coordination
properties of the mixed-donor bidentate ligands a and b in
their first described palladium(II) complexes [19]. Ligands
were made to react to several cyclometallated precursors
[Pd(C^N)(l-X)]2 [C^N = phenylazophenyl, 2-pyridinin-
phenyl, 7,8-benzoquinolyl, and 2-(2-oxazolinyl)phenyl]
whose bridging units (X = Cl, AcO or OH) exhibited differ-
ent acid–base behaviour, and a marked influence of the pre-
cursor employed in the final adopted bonding pattern was
observed. Thus, a hemilabile behaviour of ligand b was just
detected against l-AcO precursors, while amide deprotona-
tion is only achieved when l-OH starting materials were
used. On the other hand, we have contributed to the large
body of work concerning pentafluorophenyl derivatives of
group 10 metals [20] with the synthesis of the precursors
cis-[M(C6F5)2(PhCN)2] M = Ni, Pd [21], that have been
used in the preparation and characterisation of a wide vari-
ety of complexes possessing the C6F5ꢁ ligand [22,23]. In
this paper, we present the preparation of new mono- and
bis-pentafluorophenyl complexes with phosphine-amide
ligands a and b, and our structural and solution investiga-
tions on their coordination properties.
2-diphenylphosphine-N-isopropylbenzamide (a compounds)
or 2-diphenylphosphine-N-phenylbenzamide (b com-
pounds) in molar ratio 1:1, using CH2Cl2 as solvent and
according to the following general method. To a dichloro-
methane solution (10 mL) of the corresponding precursor
[M(C6F52(PhCN)2] (60 mg) was added solid 2-diphenyl-
phoshinebenzamide. The resulting solution was stirred for
60 min, filtered through a short Celite column and then
concentrated to half the volume under reduced pressure.
Addition of hexane caused precipitation of the new com-
plexes, which were filtered off, air dried and recrystallised
from dicholoromethane–hexane.
[Ni(C6F5)2(o-Ph2PC6H4CO-NHiPr)] (1a): Yield 0.089 g
(72%). Anal. Calc. for C34F10H22NOPNi: C, 55.2; H, 3.0;
N, 1.9. Found: C, 55.0; H, 3.1; N, 1.8%. FT-IR (nujol mull
cmꢁ1): m(NH) 3422(s); m(CO) 1600(vs). 1H NMR
i
(200 MHz, CDCl3): d(ppm):0.87 (m, 6H, Pr), 3.63 (m,
i
1H, Pr), 6.11 (s, 1H, aromatic), 7.32–7.61 (m, 14H, aro-
matic +NH). 31P NMR (200 MHz, CDCl3): d(ppm): 18.3
(s). 19F NMR (200 MHz, CDCl3): d(ppm): ꢁ115.1 (d,
2Fo,Jom = 20.0), ꢁ118.9 (m, 2Fo, Jom = 20.0), ꢁ161.8 (t,
1Fp, Jpm = 19.8), ꢁ162.9 (t, 1Fp, Jpm = 19.8), ꢁ164.3 (m,
2Fm), ꢁ165.1 (m, 2Fm). FAB-MS (negative mode) m/z:
572 (MꢁC6F5), 405 (Mꢁ2C6F5).
[Ni(C6F5))2o-Ph2PC6H4CO-NHPh)] (1b): Yield 0.095 g
(74%). Anal. Calc. for C37F10H20NOPNi: C, 57.4; H, 2.6;
N, 1.8. Found: C, 57.3; H, 2.7; N, 1.8%. FT-IR (nujol mull
cmꢁ1): m(NH) 3439(s); m(CO) 1608(vs). 1H NMR (200 MHz,
CDCl3): d(ppm): 6.97–7.89 (m, 19H, aromatic + NH). 31P
NMR (200 MHz, CDCl3): d(ppm):7.5 (s). 19F NMR
(200 MHz, CDCl3): d(ppm): ꢁ115.8 (m, 2Fo), ꢁ118.9 (m,
2. Experimental
2.1. General remarks
2Fo), ꢁ161.9 (t, 1Fp, Jpm = 18.8), ꢁ163.2 (t, 1Fp, Jpm
=
18.8), ꢁ164.4 (m, 2Fm), ꢁ165.3 (m, 2Fm). FAB-MS (nega-
tive mode) m/z: 606 (MꢁC6F5), 439 (Mꢁ2C6F5).
C, H, and N analyses were carried out with a Carlo Erba
instrument. IR spectra were recorded on a Perkin–Elmer
spectrophotometer 16F PC FT-IR, using Nujol mulls
between polyethylene sheets. NMR data (1H, 13C, 31P)
were recorded on Bruker Avance 200, 300 and 400 spec-
trometers. Mass spectrometric analyses were performed
on a Fisons VG Autospec double-focusing spectrometer,
operated in negative mode. Ions were produced by fast
atom bombardment (FAB) with a beam of 25-keV Cs
atoms. The mass spectrometer was operated with an accel-
erating voltage of 8 kV and a resolution of at least 1000.
All the solvents were dried by conventional methods.
The pentafluorophenyl precursors [{Pd(C6F5)(tht)-
(l-Cl)}2] and cis-[M(C6F5)2(PhCN)2] (M = Ni, Pd) were
prepared as described in the literature [20a,21]. The diph-
enylphosphinobenzamides o-Ph2PC6H4CONHR (R = iPr
a, Ph b) were prepared adapting a reported procedure [13].
[Pd(C6F5)2(o-Ph2PC6H4CO-NHiPr)] (2a): Yield 0.083 g
(68%). Anal. Calc. for C34F10H22NOPPd: C, 51.8; H, 2.8;
N, 1.8. Found: C, 51.9; H, 3.0; N, 2.0%. FT-IR (nujol mull
cmꢁ1): m(NH) 3424(s); m(CO) 1600(vs). 1H NMR
i
(400 MHz, CDCl3): d(ppm): 0.88 (d, JHH = 8.8, 6H, Pr),
i
3.86 (m, 1H, Pr), 6.03 (m, 1H, aromatic), 7.37–7.52 (m,
14H, aromatic + NH). 31P NMR (200 MHz, CDCl3):
d(ppm): 20.0 (s). 19F NMR (200 MHz, CDCl3): d(ppm):
ꢁ113.6 (m, 2Fo), ꢁ116.7 (m, 2Fo), ꢁ160.9 (t, 1Fp,
Jpm = 19,8), ꢁ162.1 (t, 1Fp, Jpm = 19,8), ꢁ163.3 (m, 2Fm),
ꢁ164.0 (m, 2Fm). FAB-MS (negative mode) m/z: 620
(MꢁC6F5), 453 (Mꢁ2C6F5).
[Pd(C6F5)2(o-Ph2PC6H4CO-NHPh)] (2b): Yield 0.073 g
(58%). Anal. Calc. for C37F10H20NOPPd: C, 54.1; H, 2.4;
N, 1.7. Found: C, 54.2; H, 2.4; N, 1.8%. FT-IR (nujol mull
cmꢁ1): m(NH) 3398(s); m(CO) 1610(vs). 1H NMR
(400 MHz, CDCl3): d(ppm): 6.98–7.90 (m, 20H, aro-
matic + NH). 31P NMR (400 MHz, CDCl3): d(ppm): 19.1
(s). 19F NMR (400 MHz, CDCl3): d(ppm): ꢁ113.8 (m,
2Fo), ꢁ116.4 (m, 2Fo), ꢁ160.5 (t, 1Fp, Jpm = 19.8),
ꢁ161.9 (t, 1Fp, Jpm = 19.8), ꢁ163.1 (m, 2Fm), ꢁ163.8 (m,
2Fm). FAB-MS (negative mode) m/z: 654 (MꢁC6F5), 487
(Mꢁ2C6F5).
2.2. Preparation of complexes [M(C6F5)2(o-Ph2-
PC6H4CO-NHR)] [M = Ni; R = iPr (1a); R = Ph (1b);
M = Pd; R = iPr (2a); R = Ph (2b)]
The new complexes were obtained by treating cis-
[M(C6F5)2(PhCN)2] (M = Ni, Pd) with previously prepared

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i
2.3. Preparation of complexes [Pd(C6F5)(Cl)(o-Ph2-
PC6H4CO-NHR)] [R = i Pr (3a); R = Ph (3b)]
6H, Pr), 2.09 (m, 8H, cod), 2.98 (s, 4H, cod), 3.78 (m,
i
1H, Pr), 7.17 (m, 1H, aromatic), 7.38 (m, 9H, aromatic),
7.50 (m, 2H, aromatic), 7.78 (m, 1H, aromatic), 8.10 (m,
1H, aromatic), 9.36 (m, 1H, NH). 31P NMR (300 MHz,
CDCl3): d(ppm): 30.0 (t, 1P, JFP = 11,3). 19F NMR
(300 MHz, CDCl3): d(ppm): ꢁ78.1 (CF3SO3), ꢁ115.5
(dd, 2Fo, Jom = 21.2; JFP = 11.3), ꢁ157.0 (t, 1Fp,
Jpm = 19.8), ꢁ160.3 (m, 2Fm). FAB-MS (negative mode)
m/z: 728 (MꢁO3SCF3).
To a dichloromethane (10 mL) solution of the precursor
[{Pd(C6F5)(tht)(l-Cl)}2] (0.1 g, 0.126 mmol) was added the
stoichiometric amount (1:2 molar ratio) of the correspond-
ing 2-diphenylphoshinebenzamide. The reaction was stir-
red at room temperature for 2 h, filtered and then
concentrated under reduced pressure. The addition of pen-
tane caused the formation of the new complexes, which
were filtered off, air dried and recrystallised from ace-
tone–pentane.
[Pd(C6F5)(cod)(o-Ph2PC6H4CO-NHPh)](O3SCF3) (4b):
Yield 0.124 g (54%). Anal. Calc. for C40F8H32NO4PSPd:
C, 52.7; H, 3.5; N, 1.5. Found: C, 52.8; H, 3.7; N, 1.6%.
FT-IR (nujol mull cmꢁ1): m(NH) 3364(s); m(CO) 1608(vs).
1H NMR (300 MHz, CDCl3): d(ppm): 1.81 (m, 8H, cod),
2.79 (s, 4H, cod), 7.09 (m, 2H, aromatic), 7.26 (m, 4H, aro-
matic), 7.39 (m, 8H, aromatic), 7.52 (m, 2H, aromatic),
7.63 (m, 1H, aromatic), 7.87 (m, 1H, aromatic), 8.39 (m,
1H, aromatic), 11.14 (m, 1H, NH). 31P NMR (300 MHz,
CDCl3): d(ppm): 29.9 (t, 1P, JFP = 12.7). 19F NMR
(200 MHz, CDCl3): d(ppm): ꢁ77.9 (CF3SO3), ꢁ115.6
(dd, 2Fo, Jom = 21.2; JFP = 12.7), ꢁ156.9 (t, 1Fp,
Jpm = 19.8), ꢁ160.3 (m, 2Fm). FAB-MS (negative mode)
m/z: 763 (MꢁO3SCF3).
[Pd(C6F5)(Cl)(o-Ph2PC6H4CO-NHiPr)] (3a): Yield
0.142 g (86%). Anal. Calc. for C28ClF5H22NOPPd: C,
51.2; H, 3.4; N, 2.1. Found: C, 51.3; H, 3.4; N, 2.1%.
FT-IR (nujol mull cmꢁ1): m(NH) 3338(s); m(CO) 1594(vs).
1H NMR (300 MHz, CDCl3): d(ppm): 0.99 (d, JHH = 6.6,
i
i
6H, Pr), 4.06 (m, 1H, Pr), 6.98–7.97 (m, 14H, aromatic),
8.66 (m, 1H, NH). 31P NMR (300 MHz, CDCl3): d(ppm):
29,6 (t, 1P, JFP = 11,8). 19F NMR (300 MHz, CDCl3):
d(ppm): ꢁ115.5 (dd, 2Fo, Jom = 22.6; JFP = 11.8), ꢁ164.0
(t, 1Fp, Jpm = 19.7), ꢁ165.7 (m, 2Fm). FAB-MS (negative
mode) m/z: 620 (MꢁCl).
[Pd(C6F5)(Cl)(o-Ph2PC6H4CO-NHPh)]
(3b):
Yield
[Pd(C6F5)(bipy)(o-Ph2PC6H4CO-NHiPr)](O3SCF3) (5a):
Yield 0.163 g (72%). Anal. Calc. for C37F8H28N3O4PSPd:
C, 49.4; H, 3.1; N, 4.7. Found: C, 49.4; H, 3.2; N, 4.7%.
FT-IR (nujol mull cmꢁ1): m(NH) 3312(s); m(CO) 1636(s);
m(bipy)1540(m). 1H NMR (300 MHz, CDCl3): d(ppm):
0.111 g (64%). Anal. Calc. for C31ClF5H20NOPPd: C,
53.9; H, 2.9; N, 2.0. Found: C, 54.0, H, 3.0; N, 2.1%.
FT-IR (nujol mull cmꢁ1): m(NH) 3265(s); m(CO) 1608(vs).
1H NMR (400 MHz, CDCl3): d(ppm): 7.19–8.29 (m, 19H,
aromatic), 10.45 (m, 1H, NH). 31P NMR (400 MHz,
CDCl3): d(ppm): 30.7 (t, 1P, JFP = 11,8). 19F NMR
(400 MHz, CDCl3): d(ppm): ꢁ115.7 (dd, 2Fo, Jom = 23.5;
JFP = 11.8), ꢁ163.7 (t, 1Fp, Jpm = 19.8), ꢁ165.5 (m, 2Fm).
FAB-MS (negative mode) m/z: 654 (MꢁCl).
i
i
0.86 (d, JHH = 6.6, 6H, Pr), 3.50 (m, 1H, Pr), 7.43–8.75
(m, 22H, aromatic), 8.97 (br, 1H, NH). 31P NMR
(300 MHz, ((CD3)2CO)): d(ppm): 33.1 (br, 1P). 19F NMR
(300 MHz, ((CD3)2CO)): d(ppm): ꢁ78.6 (CF3SO3),
ꢁ115.5 (d, 2Fo, Jom = 22.6), ꢁ160.6 (t, 1Fp, Jpm = 19.8),
ꢁ163.0 (m, 2Fm). FAB-MS (negative mode) m/z: 776
(MꢁO3SCF3).
2.4. Preparation of complexes
[Pd(C6F5)(LL){PPh2(C6H4-CONH-R)}](O3 SCF3)
[LL = cod; R = i Pr (4a), Ph (4b); LL = bipy; R = i Pr
(5a), Ph (5b)]
[Pd(C6F5)(bipy)(o-Ph2PC6H4CO-NHPh)](O3SCF3) (5b):
Yield 0.176 g (75%). Anal. Calc. for C40F8H26N3O4PSPd:
C, 51.4; H, 2.8; N, 4.5. Found: C, 51.5; H, 2.9; N, 4.5%.
FT-IR (nujol mull cmꢁ1): m(NH) 3302(s); m(CO) 1660(s);
m(bipy)1538(m). 1H NMR (300 MHz, CDCl3): d(ppm):
6.85–8.37 (m, 27H, aromatic), 9.27 (br, 1H, NH). 31P
NMR (300 MHz, ((CD3)2CO)): d(ppm): 32.1 (br,1P). 19F
NMR (300 MHz, ((CD3)2CO)): d(ppm): ꢁ78.6 (CF3SO3),
ꢁ116.8 (d, 2Fo, Jom = 28.2), ꢁ160.3 (t, 1Fp, Jpm = 19.8),
ꢁ162.6 (m, 2Fm). FAB-MS (negative mode) m/z: 810
(MꢁO3SCF3).
To a dichloromethane (cod compounds) or acetone
(bipy compounds) (10 mL) solution of the precursor
[{Pd(C6F5)(tht)(l-Cl)}2] (0.1 g, 0.126 mmol) was added
the stoichiometric amount (1:2 molar ratio) of the corre-
sponding 2-diphenylphoshinebenzamide. The reaction
was stirred at room temperature for 1 h, and then
Ag(O3SCF3) and LL ligands (bipy in 5 mL acetonitrile)
were added, allowing the reaction to stir for 30 min. The
AgCl precipitate was filtered and the solution then concen-
trated under reduced pressure to half the volume. The addi-
tion of hexane caused the formation of the new complexes,
which were filtered off, air dried and recrystallised from
acetone–hexane.
2.5. Preparation of complexes
[Pd(C6F5){S(S)P(OMe)2}(o-Ph2PC6H4CONHR)]
[R = i Pr (6a), Ph (6b)]
To a dichloromethane (10 mL) solution of the precursor
[{Pd(C6F5)(tht)(l-Cl)}2] (0.1 g, 0.126 mmol) was added the
stoichiometric amount (1:2 molar ratio) of the correspond-
ing 2-diphenylphoshinebenzamide and (NH4) [S(S)-
P(OMe)2]. The reaction was stirred at room temperature
for 1/2 hour, and then filtrated to eliminate the NH4Cl
[Pd(C6F5)(cod)(o-Ph2PC6H4CO-NHiPr)](O3SCF3) (4a):
Yield 0.110 g (50%). Anal. Calc. for C37F8H34NO4PSPd:
C, 50.6; H, 3.9; N, 1.6. Found: C, 50.8; H, 4.0; N, 1.7%.
FT-IR (nujol mull cmꢁ1): m(NH) 3372(s); m(CO) 1594(vs).
1H NMR (300 MHz, CDCl3): d(ppm): 0.95 (d, JHH = 6.9,

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1653
formed. The resulting solution was then concentrated
under reduced pressure to half the volume and the addition
of a (1:1) mixture of Et2O–pentane resulted in the precipi-
tation of the new complexes, which were filtered off,
washed with water and pentane,air dried and recrystallised
from dichloromethane–hexane.
1H, aromatic), 7.86 (m, 2H, aromatic), 8.13 (m, 1H, aro-
matic), 9.60 (m, 1H, NH). 31P NMR (300 MHz,
((CD3)2CO)): d(ppm): 106.30 (d, 1P, m), 30.5 (m, 1P). 19F
NMR (300 MHz, ((CD3)2CO)): d(ppm): ꢁ114.1 (dd, 2Fo,
Jom = 21.2, JFP = 7.1) ꢁ162.8 (t, 1Fp, Jpm = 19.8), ꢁ164.7
(m, 2Fm). FABꢁMS (negative mode) m/z: (MꢁC6F5).
[Pd(C6F5){S(S)P(OMe)2}(o-Ph2PC6H4CONHiPr)] (6a):
Yield 0.098 g (50%). Anal. Calc. for C30F5H28NO3P2S2Pd:
C, 46.3; H, 3.6; N, 1.8. Found: C, 46.4; H, 3.7; N, 1.8%.
FT-IR (nujol mull cmꢁ1): m(NH) 3386(s); m(CO) 1650(s);
2.6. Crystal structure determination of (b) (1a), (1b), (2a)
and (3a)
1
m(PS) 690(m). H NMR (300 MHz, ((CD32CO)): d(ppm):
Crystals suitable for a diffraction study were prepared
by slow diffusion of hexane into their dichloromethane
solutions. Data collection was performed at ꢁ173 °C on
a Bruker Smart CCD diffractometer with a nominal crystal
to detector distance of 6.2 cm. Diffraction data were col-
lected based on a x scan run. A total of 2524 frames were
collected at 0.3° intervals and 10 s per frame. The diffrac-
tion frames were integrated using the SAINT package
[24] and corrected for absorption with SADABS [25]. The
structures were solved by direct (b, 2a and 3a) or heavy-
atom methods [26] (1a and 1b) and refined by full-matrix
least-squares techniques using anisotropic thermal parame-
ters for non-H atoms [26] (Table 1). Hydrogen atoms were
introduced in calculated positions and refined during the
last stages of the refinement.
0.86 (d, JHH = 6.7, 6H, iPr), 3.83 (d, 6H, P–OCH3,
i
JHP = 15.0), 4.20 (m, 1H, Pr), 7.48 (m, 14H, aromatic),
7.84 (m, 1H, NH). 31P NMR (300 MHz, ((CD3)2CO)):
d(ppm): 105.40 (d, 1P, Jpp = 32.8), 30.4 (m,1P). 19F NMR
(300 MHz, ((CD3)2CO)): d(ppm): ꢁ113.4 (dd, 2Fo, Jom
=
24.0; JFP = 7.1), ꢁ163.3 (t, 1Fp, Jpm = 19.8), ꢁ164.9 (m,
2Fm). FAB-MS (negative mode) m/z: 610 (MꢁC6F5).
[Pd(C6F5){S(S)P(OMe)2}(o-Ph2PC6H4CONHPh)] (6b):
Yield 0.125 g (61%). Anal. Calc. for C33F5H26NO3P2S2Pd:
C, 48.8; H, 3.2; N, 1.7. Found: C, 48.8; H, 3.3; N, 1.7%.
FT-IR (nujol mull cmꢁ1): m(NH) 3302(s); m(CO) 1660(s);
1
m(PS) 692(m). H NMR (300 MHz, ((CD3)2CO)): d(ppm):
3.61 (d, 6H, P–OCH3, JHP = 15.3), 7.05 (m, 1H, aromatic),
7.36 (m, 13H, aromatic), 7.55 (m, 1H, aromatic), 7.72 (m,
Table 1
Crystal data and structure refinement for compounds b, 1a, 1b, 2a and 3a
b
1a
1b
2a
3a Æ H2O
Empirical formula
Formula weight
C
381.39
25H20NOP
C34H22F10NOPNi
740.21
C37H20F10NOPNi
774.22
C34H22F10NOPPd
787.90
C28H24ClF5NO2PPd
674.30
Temperature (K)
Absorption coefficient (mmꢁ1
Crystal system
100(2)
0.154
100(2)
0.772
triclinic
100(2)
0.734
100(2)
0.729
100(2)
0.904
triclinic
)
monoclinic
P21/a
9.2011(4)
19.5847(8)
11.2092(5)
90
101.4790(10)
90
1979.50 (15)
4
monoclinic
C2/c
23.3095(16)
16.0000(11)
17.5878(12)
90
95.6550(10)
90
6527.5(8)
8
monoclinic
C2/c
19.1346(9)
13.5370(6)
26.0564(12)
90
110.9410(10)
90
6303.5(5)
8
ꢀ
ꢀ
Space group
P1
P1
˚
a (A)
11.0425(5)
11.6230(5)
13.6005(6)
81.8960(10)
66.2280(10)
74.9000(10)
1541.05(12)
2
9.2344(4)
12.1146(6)
12.8823(6)
87.9650(10)
71.1000(10)
83.6000(10)
1354.96(11)
2
˚
b (A)
˚
c (A)
a (°)
b (°)
c (°)
3
˚
V (A )
Z
Dcalc (Mg mꢁ3
F(000)
)
1.280
800
1.595
748
1.576
3120
1.660
3136
1.653
676
Reflections collected
Independent reflections (Rint
Parameters
22705
4564 (0.0608)
253
18173
6949 (0.0277)
418
37395
7587 (0.0257)
460
36123
7335 (0.0253)
433
15692
6056 (0.0156)
360
)
Refinement method
full-matrix
least-squares on F2
0.0457
0.1102
0.942
full-matrix
least-squares on F2
0.0418
0.1052
0.967
full-matrix
least-squares on F2
0.0391
0.0965
0.741
full-matrix
least-squares on F2
0.0342
0.0825
1.097
full-matrix
least-squares on F2
0.0235
0.0645
0.757
a
R1
wRb
Sc
Maximum,
minimum Dq (eA
0.450,ꢁ0.381
0.531, ꢁ0.345
0.341, ꢁ0.234
0.690, ꢁ0.380
0.449,ꢁ0.644
ꢁ3
˚
)
P
P
P
a
R1 = iFo|ꢁ|Fci/ |Fo| for reflections with I > 2rI.
P
P
2
2
1=2
b
wR2 ¼ f ½wðF o2 ꢁ F c2Þ ꢂ= ½wðF o2Þ ꢂg Þ for all reflections; wꢁ1 = r2(F2) + (aP)2 + bP, were P ¼ ð2F 2c þ F 2oÞ=3 and a and b are constants set by the
program.
c
S ¼ f ½wðF 2o ꢁ F 2c Þ ꢂ=ðn ꢁ pÞg1=2; n is the number of reflections and p the total number of parameters refined.
2

1654
G. Sa´nchez et al. / Inorganica Chimica Acta 359 (2006) 1650–1658
3. Results and discussion
coordination/dissociation, in which both the deuterated
solvent and probably its water may take part, conferring
on the ligand a behaviour of hemilabile P,O chelate.
Attempts to isolate the hypothetical [Pd(C6F5)2(o-
Ph2PC6H4CO-NHPh)(CH3CN)] complex were unsuccess-
ful and the parent complex 2b was always obtained. It is
worth to mention that, in agreement with our previous
results [19], a stronger chelating character is attributable
to a in comparison with b, since analogous studies in
CD3CN for compound 2a displayed after three weeks, a
(1/1/7) ratio for signals at 29 ppm, 22 ppm and 20 ppm.
The latter resonance (being always predominant) was
attributed to the P,O chelating mode. Regarding nickel
complexes 1a and 1b, the expected affinity between hard
metal-hard donor atom may explain the absence of
dynamic processes that imply O-dissociation.
X-ray diffraction analysis has confirmed the structures
of b, 1a, 1b and 2a, providing a set of structural data that
enrich some aspects discussed above. The molecular struc-
ture of b is shown in Fig. 1, showing similar values to those
reported for related compounds (searched at the Cam-
bridge Structural Database (CSD) v. 5.26. IVONOW
[28], DOVWIU [29], AJIFII [30] and CEMPOZ [31]).
The angle between planes O(1)–C(7)–C(6) and C(6)–
C(1)–P(1) is 53.11(13)°. This value slightly diminishes once
the ligand is complexed to Ni or Pd: 38.42(22)°, 33.29(20)°
In dichloromethane, the labile precursors cis-
[M(C6F5)2(PhCN)2] [M = Ni, Pd] react at room tempera-
ture with o-Ph2PC6H4CONHR: [R = iPr a or Ph b] (see
Section 2 for details) yielding the yellow (1a, 1b) or white
(2a, 2b) compounds of general formula [M(C6F5)2(o-
Ph2PC6H4CO-NHR)] [M = Ni; R = iPr 1a; R = Ph 1b;
M = Pd; R = iPr 2a; R = Ph 2b] in which the diphenyl-
phosphine-benzamidate ligands display a g2-P,O coordina-
tion mode. The characterising spectroscopic and analytical
data are in agreement with the proposed structures pre-
sented in Scheme 1.
Infrared spectroscopy provides full information of the
situation. All complexes show the characteristic absorp-
tions of the C6F5 group [27] at ca. 1630 m, 1500 vs, 1050
s and 950 vs cmꢁ1 and two bands in the 800–780 cmꢁ1
region for the so-called ‘‘X-sensitive’’ mode of C6F5, typi-
cal of the cis-M(C6F5)2 fragment, obviously found in com-
pounds containing bidentate chelate ligands. A medium
m(NH) vibration and a m(CO) absorption, lowered in energy
by approximately 30 cmꢁ1 with respect to those of the free
ligands (a: 1624 cmꢁ1. b: 1647 cmꢁ1), indicate that the
amide ligands are O-coordinated to the respective metals.
The FAB mass spectrometry displays fragments corre-
sponding to [MꢁꢁC6F5] and [Mꢁꢁ2C6F5]. The 31P{1H}
NMR spectra of the new complexes in CDCl3 consist of
singlets around 19 ppm, while their 19F spectra show the
expected pattern of three duplicated resonance signals,
consistent with the presence of two non-equivalent C6F5
groups, one trans to O and one trans to P. In our previous
work with a and b they coordinated to different cyclomet-
allated fragments, and we pointed out the hemilability
exhibited by ligand b under certain conditions [19]. Here
modifications in this behaviour as a result of a different
chemical environment could be expected, in which the large
trans-influence exerted by the C6F5 groups may play an
important role labilizing the O–M bond. Indeed, when
the 31P{1H}spectra of 2b was run in CD3CN, two reso-
nances at ca. 28 ppm and 23 ppm were growing with time,
reaching after three weeks a (3/1.5/1) ratio in relation to
the diminishing singlet at 19 ppm. This observation sug-
gests that the amidic oxygen is involved in processes of
Fig. 1.
Ph
Ph
M
CO-NH-R
C6F5
C6F5
P
[M(C6F5)2(PhCN)2]
+
CH2Cl2
PPh2
O
NH-R
M = Ni; R = iPr 1a, Ph 1b
M = Pd; R = iPr 2a, Ph 2b
Scheme 1.

G. Sa´nchez et al. / Inorganica Chimica Acta 359 (2006) 1650–1658
1655
and 41.26(19)° for 1a, 1b and 2a, respectively. The most sig-
nificant difference between the solid state conformation of
the free ligand b and the coordinated ligand in 1b is the
relative position of the phenyl rings bonded to the N–
CO-moiety. In the free ligand both rings are nearly perpen-
dicular (81.7°) while in the complex the phenyl bonded to
N rotates, causing both rings to be parallel (10.2°). The
crystal structure analysis reveals that b forms H-bonded
chains (Fig. 2) due to intermolecular hydrogen bonding
between NH and CO functions (distance N(1)ꢀ ꢀ ꢀO(1)
T-shaped conformation [32] with an angle of 82.7° between
˚
planes and centroid–centroid distance of 4.895 A.
Upon coordination, no remarkable changes in bond dis-
tances are observed with respect to free b, except the
expected elongation in the C–O distance found in the struc-
tures of the three complexes (Table 2). Neither variations in
the Ni environment are detected when varying the R
groups (iPr in 1a (Fig. 3) or Ph in 1b (Fig. 4)). Both struc-
tures have a shorter Ni(1)–C(1) compared to Ni(1)–C(7)
and may be described as nearly planar, with a moderate
tetrahedral distortion from the ideal square-plane [33]
(Table 3). A close Ni(1)–P(1) distance has been reported
in a related complex with ligand b and a PMe3 group trans-
to P instead of C6F5 [18].
˚
2.817(2) A and angle N(1)–Hꢀ ꢀ ꢀO(1) of 152.29°. In addi-
tion Ph–N and Ph–P rings from different chains adopt a
Selected bond distances and angles for complex 2a
(Fig. 5) are given in Table 2. The Pd(1)–O(1) distance is
very similar to the one we found for a cyclometallated ben-
zoquinolyl compound, also containing the carbonyl group
of a involved in P,O chelation to a palladium centre [19].
This fact confers a comparable trans-influence to C6F5ꢁ
and a orthometallated carbon in our complexes. Ligand a
does not behave in the same way coordinating Ni and
Pd. Thus, the difference between Pd(1)–O(1) and Ni(1)–
O(1) distances is higher than the difference in distances
obtained by the sum of covalent radii, confirming the
expected hard-hard affinity between Ni and O. Both com-
plexes 1a and 2a exist as dimer in the solid state, thanks
to hydrogen bonding between F(6) and N(1) atoms (dis-
˚
tance N(1)ꢀ ꢀ ꢀF(6) 2.984(2) A and angle N(1)–Hꢀ ꢀ ꢀF(6) of
˚
150.97° and 2.983(3) A and 151.56°, respectively).
The dinuclear complex [{Pd(C6F5)(tht)(l-Cl)}2] undergo
ready bridge cleavage with a and b ligands affording the
Fig. 2.
Table 2
˚
Selected bond lengths (A) and angles (°) for complexes 1a, 1b, 2a and 3a
1a
1b
2a
3a
Ni(1)–C(1)
Ni(1)–C(7)
1.872(2)
1.931(2)
1.880(2)
1.951(2)
Ni(1)–P(1)
Ni(1)–O(1)
2.1799(6)
1.9274(15)
2.1848(6)
1.9313(14)
89.02(9)
C(1)–Ni(1)–C(7)
C(1)–Ni(1)–P(1)
C(1)–Ni(1)–O(1)
C(7)–Ni(1)–P(1)
C(7)–Ni(1)–O(1)
P(1)–Ni(1)–O(1)
Pd(1)–C(1)
89.15(9)
93.90(7)
176.32(8)
174.26(7)
91.07(8)
86.20(5)
91.80(6)
177.95(8)
171.63(7)
92.81(7)
86.53(5)
1.978(2)
1.9823(17)
Pd(1)–C(7)
2.079(2)
Pd(1)–P(1)
Pd(1)–O(1)
Pd(1)–Cl(1)
2.2737(6)
2.1086(17)
2.2114(4)
2.0976(12)
2.3691(4)
C(1)–Pd(1)–C(7)
C(1)–Pd(1)–P(1)
C(1)–Pd(1)–O(1)
C(7)–Pd(1)–P(1)
C(7)–Pd(1)–O(1)
P(1)–Pd(1)–O(1)
C(1)–Pd(1)–Cl(1)
P(1)–Pd(1)–Cl(1)
O(1)–Pd(1)–Cl(1)
85.98(9)
95.26(7)
175.87(8)
178.72(6)
94.06(7)
84.73(5)
95.04(5)
178.08(6)
83.74(4)
89.08(5)
175.863(15)
92.14(4)

1656
G. Sa´nchez et al. / Inorganica Chimica Acta 359 (2006) 1650–1658
Fig. 5.
Fig. 3.
as inferred from the coupling constants obtained in their
31P and 19F NMR spectra, lies trans to the amidic oxygen.
In this case, the amidic oxygen stays firmly bonded to
palladium and no dynamic behaviour was detected when
running the spectra in CD3CN. Thus, the presence of a
Clꢁ coligand is more prone to be displaced than both
C6F5ꢁ, when comparing with 2a and 2b, or the chelating
O- may cause the observed situation. The characterisation
in solid state was completed with the FAB mass spectrom-
etry, that showed fragments at [MꢁꢁCl], and the X-ray
crystal structure determination of complex 3a, further con-
firmed the proposed arrangement of ligands. An ORTEP
representation of 3a is presented in Fig. 6, and selected
bond distances and angles are given in Table 2.
A very slight tetrahedral distortion of the planar palla-
dium environment is observed in both 2a and 3a structures
(Table 3) and a shorter Pd(1)–P(1) is found in complex 3a,
as expected from the weaker trans-influence of Clꢁ com-
˚
pared to C6F5ꢁ. A distance Pd(1)–O(1) of 2.0976(12) A,
almost identical to that in 2a and in the previously reported
[19] complex [Pd(Bzq)(o-Ph2PC6H4CO-NHiPr)][PF6], indi-
cates that the group situated in cis-position to this bond
does not hardly affect its length. Following the recent clas-
sification of Dance and Scudder [34] for PPh3 based on
measures of torsion angles M–P–Cipso-C (Table 4), the con-
formation of Pd–PPh2C6H4COR groups is described as
good rotor for all the new complexes, presenting values
close to those which would have the ideal rotor
(T1 = T2 = T3 = 44°). According to the classification of
Allen and Taylor [35], the six membered chelated rings
show a distorted screw-boat conformation. The torsion
angles in the four new complexes do not conform to the
ideal of around 10°, 8°, 14° and 7° for 1a, 1b, 2a and 3a,
respectively.
Fig. 4.
Table 3
Distortion parameters from square planar coordination
Improper torsion angles (°)
1a
1b
2a
3a
P(1)–C(1)–C(7)–Ni(1)
O(1)–C(7)–C(1)–Ni(1)
P(1)–C(1)–C(7)–Pd(1)
O(1)–C(7)–C(1)–Pd(1)
P(1)–C(1)–Cl(1)–Pd(1)
O(1)–Cl(1)–C(1)–Pd(1)
3.57
2.58
ꢁ6.23
ꢁ0.64
ꢁ0.25
ꢁ2.84
0.22
0.98
white neutral complexes [Pd(C6F5)Cl{PPh2(C6H4-CONH-
R)}] (R = iPr 3a, Ph 3b) displayed in Scheme 2. Formation
of a P,O chelate around the Pd centre is supported by the
appearance of the m(CO) vibration in the same range men-
tioned above for complexes 2a and 2b. A single band at ca.
800 cmꢁ1 indicates the presence of just one C6F5 ring that,
New cationic complexes of general formula [Pd(C6F5)-
(LL){PPh2(C6H4-CONH-R)}](O3SCF3) (LL = cod; R =
iPr 4a, Ph 4b; LL = bipy; R = iPr 5a, Ph 5b) were obtained
from the precursor [{Pd(C6F5)(tht)(l-Cl)}2] when it was

G. Sa´nchez et al. / Inorganica Chimica Acta 359 (2006) 1650–1658
1657
Ph
Ph
Pd
S
CO-NH-R
PPh2
C6F5
Cl
P
Cl
Cl
C6F5
Pd
+
Pd
CH2Cl2
O
C6F5
S
NH-R
R = iPr 3a, Ph 3b
i) 2 PPh2(o-C6H4NHR)
1h CH2Cl2
Ph
Ph
Ph
Ph
- 2NH4Cl
P
P
C6F5
C6F5
+ 2
2AgCl
2
(TfO)
Pd
Pd
ii)(NH4)[S(S)O(OMe)2]
ii) +2 LL + 2 AgtfO
O
O
NH-R
NH-R
S
L
S
L
R = iPr 6a, Ph 6b
LL = bipy; R = iPr 4a, Ph 4b
LL = cod; R = iPr 5a, Ph 5b
Scheme 2.
treated in successive steps with a or b, Ag(O3SCF3) and
neutral LL ligands (Scheme 2). An g1-phosphine coordina-
tion mode for diphenylphosphine-benzamide ligands is
induced under these conditions, in which, as expected, both
bipy and cod show a stronger chelating ability than our
ligands. The 31P{1H} NMR spectra consist of singlets at
ca. 30 ppm, and the 19F spectra display the three reso-
nances of C6F5ꢁ and a singlet at ꢁ78 ppm corresponding
to the triflate anion. Measurements of molar conductivity
in acetone solutions indicate that the new complexes
behave as 1:1 electrolytes [36], in accordance with the pro-
posed formulae.
Also in order to force the g1-phosphine coordination
mode in our ligands we reacted [{Pd(C6F5)(tht)(l-Cl)}2]
with amonic dimethyldithiophosphate, obtaining the
monopentafluorophenyl complexes [Pd(C6F5){S(S)P(O-
Me)2}{PPh2(C6H4-CONH-R)}] (R = iPr 6a, Ph 6b) shown
in Scheme 2. In their IR spectra, the carbonyl bands appear
Fig. 6.
Table 4
Torsion angles Pd–P–Cipso–C for the three phenyl rings in each of the complexes studied
1a
1b
2a
3a
Ring 1
Ring 2
Ring 3
T (ring 1)
T (ring 2)
T (ring 3)
T1
ꢁ47.04/133.16
144.88/ꢁ34.04
ꢁ66.24/102.35
ꢁ47.07
ꢁ42.09/126.82
ꢁ12.23/167.57
109.88/ꢁ59.28
ꢁ42.09
48.57/ꢁ133.35
ꢁ45.88/132.40
140.37/ꢁ35.06
ꢁ50.79/128.63
ꢁ45.88
ꢁ149.00/27.40
ꢁ121.88/51.14
48.57
ꢁ34.04
ꢁ12.23
27.40
51.14
27.40
ꢁ35.06
ꢁ66.24
ꢁ59.28
ꢁ50.79
34.04
12.23
35.06
T2
47.07
42.09
48.57
45.88
T3
66.24
59.28
51.14
50.79
T2–T1
T3–T2
13.03
19.17
29.86
17.19
21.17
2.57
10.82
4.91
Rotor type
Good rotor
Good rotor
Good rotor
Good rotor

1658
G. Sa´nchez et al. / Inorganica Chimica Acta 359 (2006) 1650–1658
[14] M. Tollabi, E. Framery, C. Goux-Henry, D. Sinou, Tetrahedron:
Asymmetry 14 (2003) 3329.
[15] N.W. Boaz, J.A. Ponasik, S.E. Large, S.D. Debenham, Tetrahedron:
Asymmetry 15 (2004) 2151.
[16] F.Y. Kwong, W.H. Lam, C.H. Yeung, K.S. Chan, A.S.C. Chan,
Chem. Commun. (2004) 1922.
[17] W.-M. Dai, Y. Zhang, Tetrahedron Lett. 46 (2005) 1377.
[18] H.Y. Kwon, S.Y. Lee, B.Y. Lee, D.M. Shin, Y.K. Chung, J. Chem.
Soc., Dalton Trans. (2004) 921.
in the range of non-coordinated oxygen, and the absorp-
tions attributed to the coordinated dithiophosphate are
observed in the 960–1050 and 630–690 regions [37]. The
presence of this group is also confirmed by 1H and
31P{1H} NMR spectroscopy, being observed a doublet res-
onance for the Me groups strongly coupled to P in the for-
mer, and a signal around 106 ppm that accompanies the
multiplet due to a or b at 30 ppm in the latter.
´
´
´
[19] G. Sanchez, J. Garcıa, D. Meseguer, J.L. Serrano, L. Garcıa, J.
´
´
Perez, G. Lopez, J. Chem. Soc., Dalton Trans. (2003) 4709.
4. Supplementary material
´
´
´
[20] (a) R. Uson, J. Fornies, R. Navarro, G. Garcıa, Inorg. Chim. Acta
33 (1979) 69;
´
´
´
´
(b) R. Uson, J. Fornies, F. Martınez, M. Tomas, J. Chem. Soc.,
Crystallographic data (excluding structure factors)
reported in this paper have been deposited with Cambridge
Crystallographic Data Centre as supplementary publica-
tions nos. CCDC-278159 (b), CCDC-278160(1a), CCDC-
278161 (1b), CCDC-278162 (2a) and CCDC-278163 (3a).
Copies of the data can be obtained free of charge on appli-
cation to CCDC, 12 Union Road, Cambridge CB21EZ
(fax: +44 1223 336 033; e-mail: deposit@ccdc.cam.ac.uk).
Dalton Trans. (1980) 888;
(c) R. Uson, J. Fornies, Adv. Organomet. Chem. 28 (1988) 219.
[21] (a) C. de Haro, G. Garcıa, G. Sanchez, G. Lopez, J. Chem. Res., S
´
´
´
´
´
(1986) 119;
(b) G. Lo´pez, G. Garc´ıa, J. Ruiz, G. Sa´nchez, J. Garc´ıa, C. Vicente,
Chem. Commun. (1989) 1045.
´
´
´
´
[22] (a) G. Lopez, G. Garcıa, C. de Haro, G. Sanchez, J. Garcıa, J.
Organomet. Chem. 317 (1986) C23;
(b) G. Lopez, G. Garcıa, M.D. Santana, G. Sanchez, J. Ruiz, J.A.
´
´
´
´
Hermoso, A. Vegas, M. Martınez-Ripoll, J. Chem. Soc., Dalton
Trans. (1990) 1621;
Acknowledgement
´
´
(c) G. Sanchez, J.L. Serrano, F. Ruiz, G. Lopez, J. Fluorine Chem.
91 (1998) 165;
´
Financial support of this work by Direccion General de
´
´
(d) G. Sanchez, J.L. Serrano, F. Momblona, F. Ruiz, J. Garcıa, J.
´
Investigacion (project-CTQ2005-09231-C02-01/02) is grate-
´
´
Perez, G. Lopez, P.A. Chaloner, P. Hitchcock, Polyhedron 20 (2001)
fully acknowledged.
571.
[23] R.P. Hughes, A.J. Ward, J.A. Golen, C.D. Incarvito, A.L. Rheingold,
L.N. Zakharov, J. Chem. Soc., Dalton Trans. (2004) 2720, and
references therein.
References
[24] SAINT, Version 6.22, Bruker AXS Inc.
[1] A. Bader, E. Lindner, Coord. Chem. Rev. 108 (1991) 27.
[2] G.R. Newkome, Chem. Rev. 93 (1993) 2067.
[3] C.S. Slone, D.A. Weinberger, C.A. Mirkin, Prog. Inorg. Chem. 48
(1999) 233.
[25] G.M. Sheldrick, SADABS, University of Gottingen, Germany, 1996.
[26] G.M. Sheldrick, SHELX-97. Programs for Crystal Structure Analysis
¨
(Release 97-2), University of Gottingen, Germany, 1998.
¨
[27] E. MaslowskyVibrational Spectra of Organometallic Compounds,
[4] P. Braustein, F. Naud, Angew. Chem. Int. Ed. 40 (2001) 680, and
references therein.
437, Wiley, New York, 1977.
[28] S. Burger, B. Therrien, G. Suss-Fink, Inorg. Chim. Acta 357 (2004)
[5] P. Braustein, J. Organomet. Chem. 689 (2004) 3953, and references
therein.
[6] G.M. Kapteijn, M.P.R. Spee, D.M. Grove, H. Kooijman, A.L. Spek,
G. van Koten, Organometallics 15 (1996) 1405.
1213.
[29] J.D.G. Correia, A. Domingos, I. Santos, Eur. J. Inorg. Chem. (2000)
1523.
[30] S. Burger, B. Therrien, G. Suss-Fink, Eur. J. Inorg. Chem. (2003)
¨
[7] P. Braunstein, C. Frison, X. Morise, R.A. Adams, J. Chem. Soc.,
Dalton Trans. (2000) 2205.
[8] M.S. Khoshbin, M.V. Ovchinnikov, C.A. Mirkin, L.N. Zakharov,
A.L. Rheingold, Inorg. Chem. 44 (2005) 496, and references therein.
[9] C.W. Rogers, Y. Zhang, B.O. Patrick, W.E. Jones Jr., M.O. Wolf,
Inorg. Chem. 41 (2002) 1162.
[10] C.W. Rogers, M.O. Wolf, Coord. Chem. Rev. 233–234 (2002) 341.
[11] C.W. Rogers, M.O. Wolf, Angew. Chem. Int. Ed. 41 (2002) 1898.
[12] M. Kuriyama, K. Nagai, K. Yamada, Y. Miwa, T. Taga, K.
Tomioka, J. Am. Chem. Soc. 124 (2002) 8932.
[13] T. Mino, K. Kashihara, M. Yamashita, Tetrahedron: Asymmetry 12
(2001) 287.
3099.
[31] C.P. Butts, J. Crosby, G.C. Lloyd-Jones, S.C. Stephen, Chem.
Commun. (1999) 1707–1708.
[32] M.J. Calhorda, Chem. Commun. (2000) 801.
[33] J. Pe´rez, L. Garc´ıa, E. Pe´rez, J.L. Serrano, J.F. Mart´ınez, G. Sa´nchez,
G. Lo´pez, A. Espinosa, M. Liu, F. Sanz, New J. Chem. 27 (2003)
1490.
[34] I. Dance, M. Scudder, J. Chem. Soc., Dalton Trans. (2000) 1579.
[35] F.H. Allen, R. Taylor, Acta Cryst. B 47 (1991) 404.
[36] W.J. Geary, Coord. Chem. Rev. 7 (1971) 81.
[37] R. Visalakshi, V.K. Jain, G.S. Rao, Spectrochim. Acta A 43 (1987)
1235.