The first family of platinum(IV) acetonyl complexes. mono-, bis-, and tris(acetonyl) derivatives

Article abstract of DOI:10.1021/om0605027

[Hg{CH₂C(O)Me}₂] and K[PtCl₃(C ₂H₄)] react (2:1 molar ratio) to give K[Pt ₂{CH₂C(O)Me}₆(μ-Cl)₃] (1·K) through the intermediate K[Pt{CH₂C(O)Me}Cl

Full text of DOI:10.1021/om0605027

4404
Organometallics 2006, 25, 4404-4413
The First Family of Platinum(IV) Acetonyl Complexes. Mono-, Bis-,
and Tris(acetonyl) Derivatives†
Jose´ Vicente,* Aurelia Arcas,‡ and Jesu´s M. Ferna´ndez-Herna´ndez
Grupo de Qu´ımica Organometa´lica, Departamento de Qu´ımica Inorga´nica, Facultad de Qu´ımica,
UniVersidad de Murcia, Aptdo. 4021, E-30071 Murcia, Spain
Delia Bautista
SACE, UniVersidad de Murcia, Aptdo. 4021, E-30071 Murcia, Spain
ReceiVed June 6, 2006
[Hg{CH2C(O)Me}2] and K[PtCl3(C2H4)] react (2:1 molar ratio) to give K[Pt2{CH2C(O)Me}6(µ-Cl)3]
(1‚K) through the intermediate K[Pt{CH2C(O)Me}Cl2(η2-CH2dCH2)] (2‚K). The anionic complex 1 has
been also obtained as the [K(18-C-6)]+ salt (1‚C) by reacting 1‚K with 18-crown-6, and 2 has been
isolated as the Me4N salt (2‚NMe4) by reacting [Hg{CH2C(O)Me}2] and K[PtCl3(C2H4)] (1:2) in the
presence of an excess of (Me4N)Cl. The tris(acetonyl) Pt(IV) complexes fac-(PPN)2[Pt{CH2C(O)Me}3-
t
Cl3] (3), fac-[Pt{CH2C(O)Me}3(Cl)L2] (L ) BuNC (4), XyNC (5; Xy ) C6H3Me2-2,6)), and fac-[Pt-
{CH2C(O)Me}3Cl(N∧N)] (N∧N ) bpy (6), phen (7)) have been obtained by reacting 1‚K with (PPN)Cl,
L, and N∧N, respectively, and fac-[Pt{CH2C(O)Me}3(CNtBu)(bpy)]OTf (8) was obtained from 6, TlTfO,
t
and BuNC. The mono(acetonyl) complex mer-[Pt{CH2C(O)Me}Cl3(bpy)] (9) and the bis(acetonyl) Pt-
(IV) derivatives [OC-6-13]-[Pt{CH2C(O)Me}2Cl2(bpy)] (10) and [OC-6-43]-[Pt{CH2C(O)Me}2(Me)I-
(bpy)] (11) have been obtained by reacting [Pt{CH2C(O)Me}Cl(bpy)] with PhICl2 and by reacting
[Pt{CH2C(O)Me}2(bpy)] with PhICl2 and MeI, respectively. Room-temperature isomerization of 11 gives
[OC-6-34]-[Pt{CH2C(O)Me}2(Me)I(bpy)] (12). The first mixed ketonylmetal complex, [OC-6-33]-[Pt-
{CH2C(O)Me}2{CH2C(O)Ph}Br(bpy)] (13), has been obtained by reacting [Pt{CH2C(O)Me}2(bpy)] with
PhC(O)CH2Br. The crystal structures of 1‚C, 6, 8, and 9 have been determined.
irradiation of a [PtCl6]2-solution in acetone (no isolated yield
was reported),6 and by reacting K2[PtCl4] with iodoacetone in
water.7,8
Introduction
We are interested in the synthesis of ketonylmetal complexes,
M-CH2C(O)R (R ) hydrocarbyl),1,2 because they are involved
in important organic reactions.3 The chemistry of ketonyl Pt-
(IV) complexes is poorly developed, and none of the few
reported complexes has been characterized by X-ray diffraction
studies.4 Only the monoketonyl complexes [Pt{CH2C(O)Ph}-
Me2(X)(N∧N)]n+ (N∧N ) 2,9-dimethyl-1,10-phenanthroline;
X ) Br, I, n ) 0; X ) MeCN, n ) 1), (NH4)[Pt{CH2C(O)-
Me}Cl4(NH3)], and K2[Pt{CH2C(O)Me}Cl5] have been obtained
respectively by reacting [PtMe2L2] with XCH2C(O)Ph,5 by light
We are involved in the study of the reactivity of organomer-
cury complexes as transmetalating agents.9-12 In this context,
using [Hg{CH2C(O)Me}2] as the transmetalating agent, we have
reported the synthesis of the simple (acetonyl)palladium(II)
complex [Pd{CH2C(O)Me}Cl]n, which has allowed us to
prepare a variety of mono(acetonyl)palladium(II) complexes and
the first complexes containing the chelating κ2(C,O)-C(NHR)d
CHC(O)Me (R ) tBu, Xy) ligand, resulting from the insertion
of isocyanide into the Pd-CH2C(O)Me bond and a subsequent
â-ketoimine to â-ketoenamine tautomerization process.11,13 Here
we describe the reaction between [Hg{CH2C(O)Me}2] and
K[PtCl3(C2H4)] to give the tris(acetonyl)platinum(IV) complex
* To whom correspondence should be addressed. E-mail: jvs1@um.es.
Web: http://www.um.es/gqo/.
† Dedicated to Dr. Jose´-Antonio Abad, with best wishes, on the occasion
of his retirement.
‡ E-mail: aurelia@um.es.
(6) Nizova, G. V.; Serdobov, M. V.; Nikitaev, A. T.; Shul’pin, G. B. J.
Organomet. Chem. 1984, 275, 139. Shul’pin, G. B.; Nizova, G. V.; Shilov,
A. E. J. Chem. Soc., Chem. Commun. 1983, 671.
(7) Zamaschikov, V. V.; Rudakov, E. S.; Mitchenko, S. A.; Nizova, G.
V.; Kitaigorodskii, A. N.; Shul’pin, G. B. Bull. Acad. Sci. USSR, DiV. Chem.
Sci. 1984, 33 (part 2), 1520.
(8) Shilov, A. E.; Shul’pin, G. B. Chem. ReV. 1997, 97, 2879.
(9) Vicente, J.; Chicote, M. T.; Ram´ırez-de-Arellano, M. C.; Pelizzi, G.;
Vitali, F. J. Chem. Soc., Dalton Trans. 1990, 279. Vicente, J.; Martin, J.;
Solans, X.; Font-Altaba, M. Organometallics 1989, 8, 357. Vicente, J.;
Chicote, M. T.; Arcas, A.; Artigao, M. Inorg. Chim. Acta 1982, 65, L251.
(10) Vicente, J.; Arcas, A.; Ferna´ndez-Herna´ndez, J. M.; Sironi, A.;
Masciocchi, N. Chem. Commun. 2005, 1267.
(1) Vicente, J.; Bermu´dez, M. D.; Chicote, M. T.; Sa´nchez-Santano, M.
J. J. Chem. Soc., Chem. Commun. 1989, 141. Vicente, J.; Bermu´dez, M.
D.; Chicote, M. T.; Sa´nchez-Santano, M. J. J. Chem. Soc., Dalton Trans.
1990, 1945. Vicente, J.; Bermu´dez, M. D.; Escribano, J.; Carrillo, M. P.;
Jones, P. G. J. Chem. Soc., Dalton Trans. 1990, 3083. Vicente, J.; Abad,
J. A.; Cara, G.; Jones, P. G. Angew. Chem., Int. Ed. Engl. 1990, 29, 1125.
Vicente, J.; Bermu´dez, M. D.; Carrillo, M. P.; Jones, P. G. J. Chem. Soc.,
Dalton Trans. 1992, 1975.
(2) Vicente, J.; Abad, J. A.; Chicote, M. T.; Abrisqueta, M.-D.; Lorca,
J.-A.; Ram´ırez de Arellano, M. C. Organometallics 1998, 17, 1564.
(3) Culkin, D. A.; Hartwig, J. F. Acc. Chem. Res. 2003, 36, 234. Chen,
G. S.; Kwong, F. Y.; Chan, H. O.; Yu, W. Y.; Chan, A. S. C. Chem.
Commun. 2006, 1413. Sodeoka, M.; Hamashima, Y. Bull. Chem. Soc. Jpn.
2005, 78, 941.
(11) Vicente, J.; Arcas, A.; Ferna´ndez-Herna´ndez, J. M.; Bautista, D.
Organometallics 2001, 20, 2767.
(4) Cambridge Structural Database, version 5.27 (Jan 2006). Cambridge
Crystallographic Data Center: http://www.ccdc.cam.ac.uk.
(5) De Felice, V.; Giovannitti, B.; Derenzi, A.; Tesauro, D.; Panunzi,
A. J. Organomet. Chem. 2000, 594, 445.
(12) Vicente, J.; Abad, J. A.; Rink, B.; Herna´ndez, F.-S.; Ram´ırez de
Arellano, M. C. Organometallics 1997, 16, 5269.
(13) Vicente, J.; Arcas, A.; Ferna´ndez-Herna´ndez, J. M.; Bautista, D.;
Jones, P. G. Organometallics 2005, 24, 2516.
10.1021/om0605027 CCC: $33.50 © 2006 American Chemical Society
Publication on Web 07/29/2006

Platinum(IV) Acetonyl Complexes
Organometallics, Vol. 25, No. 18, 2006 4405
Synthesis of [K(18-C-6)][Pt2{CH2C(O)Me}6(µ-Cl)3] (1‚C). To
a suspension of 1‚K (35 mg, 0.04 mmol) in acetone (2 mL) was
added 18-C-6 (16 mg, 0.06 mmol). The resulting solution was
filtered through Celite, and the filtrate was concentrated to dryness.
The residue was stirred with Et2O (10 mL) for 15 min at 0 °C, the
suspension was filtered, and the solid was air-dried to give 1‚C as
a colorless solid. Yield: 36 mg, 80%. Mp: 148 °C. ΛM (acetone,
4.11 × 10-4 mol L-1): 83 Ω-1 cm2 mol-1. IR (Nujol, cm-1): ν-
(CO) 1682; ν(PtCl) 250, 232. 1H NMR (300 MHz, d6-acetone): δ
3.66 (s, 24 H, CH2, 18-C-6), 3.19 (s, 12 H, CH2, 2JHPt ) 103 Hz),
2.12 (s, 18 H, Me). 13C{1H} NMR (200 MHz, d6-acetone): δ 210.9
K[Pt2{CH2C(O)Me}6(µ-Cl)3], the crystal structure of which has
been solved by X-ray powder diffraction. This process represents
the first example of the use of a reagent in successive
transmetalation and redox reactions, and the complex itself is
the first fully characterized ketonyl Pt(IV) complex, the first
diplatinum(IV) complex containing three bridging halo ligands,
and the first tris(ketonyl)metal complex ever isolated. An inter-
mediate Pt(II) acetonyl complex, [Pt{CH2C(O)Me}Cl2(C2H4)]-,
has been detected and isolated as the Me4N salt. These results
have been the subject of a preliminary communication.10 In this
paper we report (i) full details of the aforementioned reaction
and the synthesis and single-crystal X-ray diffraction study of
[K(18-C-6)][Pt2{CH2C(O)Me}6(µ-Cl)3] (18-C-6 ) 18-crown-
6), whose data confirm those obtained for the anion in an X-ray
powder diffraction study of K[Pt2{CH2C(O)Me}6(µ-Cl)3], (ii)
the synthesis of the first family of tris(ketonyl) Pt(IV) com-
plexes, including neutral, anionic, and cationic derivatives, (iii)
the synthesis, through oxidative addition reactions, of mono-
(acetonyl), the first bis(ketonyl), and additional members of the
new family of tris(acetonyl) Pt(IV) complexes, and (iv) the first
X-ray single-crystal structures of ketonyl Pt(IV) complexes.
2
(CO, JCPt ) 48 Hz), 71.8 (CH2, 18-C-6), 33.9 (Me), 26.8 (CH2
1JCPt ) 657 Hz). 195Pt{1H} NMR (85.88 MHz, CDCl3): -1730 (s).
Anal. Calcd for C30H54Cl3KO12Pt2: C, 31.54; H, 4.76. Found: C,
31.81; H, 4.74. Single crystals of 1‚C were obtained by slow
diffusion of Et2O into an acetone solution of 1‚C.
Synthesis of cis-(Me4N)[Pt{CH2C(O)Me}Cl2(C2H4)] (2‚NMe4).
To a solution of K[PtCl3(C2H4)] (610 mg, 1.65 mmol) in acetone
(17 mL) were added (Me4N)Cl (340 mg, 3.1 mmol) and [Hg{CH2C-
(O)Me}2] (280 mg, 0.89 mmol). The suspension was stirred for
6.5 h and then was concentrated to dryness. The residue was stirred
in CH2Cl2 (10 mL), the suspension was filtered through Celite, and
the filtrate was concentrated to ca. 2 mL. The addition of Et2O (10
mL) gave a suspension, which was filtered, and the solid was air-
dried to give 2‚NMe4 as a pale yellow solid. Yield: 580 mg, 83%.
Experimental Section
Mp: 72 °C. ΛM (acetone, 5 × 10-4 mol L-1): 114 Ω-1 cm2 mol-1
.
The reactions were carried out without precautions to exclude
light or atmospheric oxygen or moisture. Melting points were
determined on a Reicher apparatus and are uncorrected. Elemental
analyses were carried out with a Carlo Erba 1106 microanalyzer.
Molar conductivities were measured on ca. 5 × 10-4 mol L-1
acetone solution with a Crison Micro CM2200 conductimeter. IR
spectra were recorded on a Perkin-Elmer 16F PC FT-IR spectrom-
eter with Nujol mulls between polyethylene sheets or KBr pellets.
NMR spectra were recorded on Varian Unity 300, Bruker AC 200,
Avance 300 and 400, and Bruker 600 spectrometers at room
temperature. Chemical shifts are referenced to TMS (1H, 13C), H3-
PO4 (31P), or Na2PtCl6 (195Pt). When needed, NMR assignments
were performed with the help of APT, DEPT, COSY, and one-
dimensional NOE experiments and HETCOR techniques. [Hg-
{CH2C(O)Me}2],14 K[PtCl3(C2H4)],15 [Pt{CH2C(O)Me}2(bpy)], [Pt-
{CH2C(O)Me}Cl(bpy)],2 and PhICl216 were prepared according to
literature methods.
1
IR (Nujol, cm-1): ν(CO) 1647, ν(CN) 947, ν(PtCl) 311, 264. H
NMR (400 MHz, d6-acetone): δ 3.73 (br, C2H4, 2JHPt ) 66.7 Hz),
3.45 (s, 12 H, NMe4), 2.34 (s, 2 H, PtCH2, 2JHPt ) 106.5 Hz), 2.10
1
(s, 3 H, MeCO). H NMR (400 MHz, CDCl3): δ 3.94 (br, 4 H,
C2H4, 2JHPt ) 67.8 Hz), 3.44 (s, 12 H, NMe4), 2.43 (s, 2 H, PtCH2,
2JHPt ) 106.8 Hz), 2.23 (s, 3 H, MeCO). 13C{1H} NMR (100.81
MHz, CDCl3): δ 213.4 (s, CO, 2JCPt ) 46 Hz), 64.91 (C2H4, 1JCPt
) 230 Hz), 56.4 (t {1:1:1}, Me4N, 1JNC ) 4 Hz), 31.0 (s, MeCO),
1
22.1 (s, PtCH2, JCPt ) 619 Hz). 195Pt{1H} NMR (86.18 MHz,
CDCl3): δ -3378.6 (s). Anal. Calcd for C9H21Cl2OPt: C, 25.42;
H, 4.98; N, 3.29. Found: C, 25.49; H, 4.95; N, 3.16.
Synthesis of fac-(PPN)2[Pt{CH2C(O)Me}3Cl3] (3). To a sus-
pension of 1‚K (23.7 mg, 0.03 mmol) in CH2Cl2 (3 mL) was added
(PPN)Cl (62 mg, 0.11 mmol). After 10 min of stirring, the
suspension was filtered through Celite and the filtrate was
concentrated (1 mL). Addition of Et2O (10 mL) gave a suspension
which was stirred for 1 h in a water/ice bath and filtered off. The
colorless solid was washed with Et2O (5 mL) and air-dried to give
3. Yield: 70 mg, 84%. Mp: 158 °C. ΛM (acetone, 3.87 × 10-4
mol L-1): 208 Ω-1 cm2 mol-1. IR (Nujol, cm-1): ν(CO) 1665,
Synthesis of K[Pt2{CH2C(O)Me}6(µ-Cl)3] (1‚K). To a solution
of K[PtCl3(C2H4)] (250 mg, 0.68 mmol) in acetone (10 mL) was
added [Hg{CH2C(O)Me}2] (430 mg, 1.37 mmol). The resulting
suspension was stirred for 20 h at room temperature and then
concentrated to dryness. The resulting gray solid was washed with
CH2Cl2 (3 × 5 mL) and refluxed for 40 min in MeCN (10 mL),
and the hot suspension was filtered through Celite. The yellow
filtrate was concentrated until a colorless solid started to precipitate.
Et2O (5 mL) was added, the suspension was filtered off, and the
solid was recrystallized from MeCN/Et2O to give 1 as a colorless
microcrystalline solid. Yield: 102 mg, 74%. Mp: 200 °C dec. ΛM
(acetone, 5 × 10-4 mol L-1): 106 Ω-1 cm2 mol-1. IR (cm-1): ν-
(CO) 1689, ν(PtCl) 245. 1H NMR (400 MHz, d6-acetone): δ 3.20
1
ν(PtCl) 265, 241(br). H NMR (300 MHz, CDCl3): δ 7.71-7.40
(m, 60 H, PPN), 3.30 (s, 6 H, CH2, 2JHPt ) 102 Hz), 2.19 (s, 9 H,
2
Me). 13C{1H} NMR (50.30 MHz, CDCl3): δ 211.9 (CO, JCPt
)
48 Hz), 133.9 (m, PPN, Cp), 131.9 (m, PPN, Cm), 129.5 (m, PPN,
1
3
Co), 126.7 (dd, PPN, Cipso, JCP ) 108 Hz, JCP ) 1.7 Hz), 32.9
(Me), 25.4 (CH2, JCPt ) 651 Hz). 31P{1H} NMR (121.50 MHz,
1
CDCl3): δ 21.1. 195Pt{1H} NMR (86.50 MHz, CDCl3): δ -1739.
Anal. Calcd for C81H75Cl3N2O3P4Pt: C, 62.77; H, 4.88; N, 1.81.
Found: C, 62.57; H, 4.90; N, 1.91.
2
(s, 2 H, CH2, JHPt ) 103 Hz), 2.12 (s, 3 H, Me). 13C{1H} NMR
Synthesis of fac-[Pt{CH2C(O)Me}3Cl(CNtBu)2] (4). To a
suspension of 1‚K (36 mg, 0.04 mmol) in acetone (3 mL) was added
tBuNC (30 µL, 0.26 mmol). The reaction mixture was stirred for 5
h and filtered through Celite. The filtrate was concentrated to give
a pale yellow oil that was washed with n-pentane (3 mL) and
vacuum-dried for 24 h to give 4 as a pale yellow solid. Yield: 30
mg, 64%. Mp: 74-80 °C. IR (Nujol, cm-1): ν(CN) 2242, 2227,
ν(CO) 1681, ν(PtCl) 271. 1H NMR (400 MHz, CDCl3): δ 3.04 (d,
2 H, CH2, 2JHH ) 7.0 Hz, 2JHPt ) 91.7 Hz), 2.98 (s, 2 H, CH2 trans
(50.30 MHz, d6-acetone): δ 210 (CO), 32.9 (Me), 25.8 (CH2, 1JCPt
) 657 Hz). 95Pt{1H} (85.88 MHz, d6-acetone): δ -1743 (s). ESI-
MS (-): m/z 839 [M - K+]-; 437 [Pt(CH2C(O)Me)3Cl2]-. Anal.
Calcd for C18H30Cl3KO6Pt2: C, 24.62; H, 3.44. Found: C, 24.62;
H, 3.44.
(14) Nesmeyanov, A. N. Selected Works in Organic Chemistry; Pergamon
Press: Oxford, U.K., 1963; p 385. Lutsenko, I. F.; Khomutov, R. M. Dokl.
Akad. Nauk SSSR 1953, 88, 837.
(15) Chock, P. B.; Halpern, J.; Paulik, F. E. Inorg. Synth. 1973, 14, 90.
(16) Vicente, J.; Chicote, M. T.; Gonza´lez-Herrero, P.; Jones, P. G. Inorg.
Chem. 1997, 36, 5735.
2
t
to Cl, JHPt ) 89.8 Hz), 2.27 (s, 6 H, MeC(O) trans to BuNC),
t
2
2
2.26 (d, 2 H, CH2 trans to BuNC, JHH ) 7.0 Hz, JHPt ) 67.5
Hz), 2.23 (s, 3 H, MeC(O), 3JHPt ) 4.8 Hz), 1.57 (s, 18 H, CMe3).

4406 Organometallics, Vol. 25, No. 18, 2006
Vicente et al.
13C{1H} NMR (150.9 MHz, CDCl3): δ 213.8 (CO trans to tBuNC,
Synthesis of fac-[Pt{CH2C(O)Me}3Cl(phen)] (7). To a suspen-
sion of 1‚K (32 mg, 0.04 mmol) in acetone (4 mL) was added
phen‚H2O (29 mg, 0.14 mmol), and the mixture was stirred for 6
h and then filtered through Celite. The filtrate was concentrated (1
mL), Et2O (10 mL) was added, and the resulting suspension was
stirred in a water/ice bath. The suspension was filtered, and the
solid was washed with Et2O (5 mL) and air-dried to give 7 as a
yellow solid. Yield: 32 mg, 75%. Mp: 167 °C. IR (Nujol, cm-1):
2
2JCPt) 33 Hz), 211.3 (CO, JCPt ) 42 Hz), 117.1 (t {1:1:1}, CN,
1JCN ) 18 Hz, 1JCPt ) 816 Hz), 58.8 (C(Me)3), 31.4 (MeC(O) trans
t
t
to BuNC), 31.1 (MeC(O) trans to Cl), 29.9 (CH2 trans to BuNC,
1JCPt ) 463 Hz), 29.6 (CMe3), 25.9 (CH2 trans to Cl, 1JCPt ) 548.0
Hz). 195Pt{1H} NMR (86.18 MHz, CDCl3): δ -3343 (q, {1:2:3:2:
1}, 2JNPt ) 22 Hz). Anal. Calcd for C19H33ClN2O3Pt: C, 40.18; H,
5.86; N, 4.93. Found: C, 39.83; H, 5.87; N, 5.03.
1
ν(CO) 1669, ν(PtCl) 265. H NMR (400 MHz, CDCl3): δ 9.89
Synthesis of fac-[Pt{CH2C(O)Me}3Cl(CNXy)2] (5). To a
suspension of 1‚K (33 mg, 0.04 mmol) in acetone (3 mL) was added
XyNC (27 mg, 0.20 mmol). The reaction mixture was stirred for 5
h and filtered through Celite. The filtrate was concentrated to
dryness to give a yellow oil which was washed with n-pentane (2
× 5 mL) and vacuum-dried for 24 h, to give 5 as a pale yellow oil.
Yield: 40 mg, 81%. 1H NMR (400 MHz, CDCl3): δ 7.25 (m, 2 H,
CH, Xy), 7.12 (m, 4 H, CH, Xy), 3.25 (s, 2 H, CH2 trans to Cl,
2JHPt ) 85.3 Hz), 3.23 (d, 2 H, CH2 trans to XyNC, 2JHH ) 7.5 Hz,
2JHPt ) 85.3 Hz), 2.52 (d, 2 H, CH2 trans to XyNC, 2JHH ) 7.5 Hz,
2JHPt ) 68.7 Hz), 2.49 (s, 12 H, Me, Xy), 2.33 (s, 3 H, MeC(O),
4JHPt ) 5.3 Hz), 2.26 (s, 6 H, MeC(O)). 13C{1H} NMR (100.8 MHz,
CDCl3): δ 213.8 (CO, trans to XyNC, 2JCPt ) 33 Hz), 211.4 (CO,
trans to Cl, 2JCPt ) 42 Hz), 136.5 (C, Xy), 130.5 (CH, Xy), 128.9
(t, {1:1:1}, XyNC), 128.1 (CH, Xy), 125.0 (br, C, Xy), 31.4 (MeC-
(O) trans to XyNC), 30.8 (MeC(O) trans to Cl, 3JCPt ) 8 Hz), 30.0
(CH2 trans to XyNC, 1JCPt ) 468 Hz), 26.8 (CH2 trans to Cl, 1JCPt
) 565 Hz), 18.4 (Me, Xy). 195Pt{1H} NMR (86.18 MHz, CDCl3):
δ -3307 (br). Anal. Calcd for C27H33ClN2O3Pt: C, 48.83; H, 5.01;
N, 4.22. Found: C, 48.70; H, 4.79; N, 4.13.
(dd, 2 H, CH, phen, 3JHH ) 5.2 Hz, 4JHH ) 1.3 Hz), 8.55 (dd, 2 H,
3
4
CH, phen, JHH ) 8.1 Hz, JHH ) 1.3 Hz), 8.03 (dd, 2 H, CH,
3
3
phen, JHH ) 8.1 Hz, JHH ) 5.2 Hz), 8.01 (s, 2 H, CH, phen),
2
3.75 (HA, AB system, 2 H, CH2 trans to phen, JH
2JH ) 92.7 Hz), 3.69 (HA, AB system, 2 H, CH2, JH
) 8.5 Hz,
AHB
AHB
2
) 8.5
APt
2
2
Hz, JH Pt ) 98.2 Hz), 2.66 (s, 2 H, CH2 trans to Cl, JHPt ) 92.1
B
Hz), 2.33 (s, 6 H, Me trans to phen), 1.08 (s, 3 H, Me trans to Cl).
13C{1H} NMR (100.81 MHz, CDCl3): δ 214 (CO trans to phen,
2JCPt ) 33 Hz), 210.0 (CO trans to Cl, 2JCPt ) 31 Hz), 150.1 (CH,
phen, JCPt ) 15 Hz), 146.2 (C, phen), 138.8 (CH, phen), 131.1 (C,
phen, JCPt ) 10 Hz), 127.7 (CH, phen), 125.9 (CH, phen, JCPt
)
17 Hz), 33.8 (Me trans to phen), 31.2 (Me trans to Cl), 24.4 (CH2
trans to Cl, 1JCPt ) 584 Hz), 19.9 (CH2 trans to phen, 1JCPt ) 586
Hz). 195Pt{1H} NMR (86.18 MHz, CDCl3): δ -2017. Anal. Calcd
for C21H23ClN2O3Pt: C, 43.34; H, 3.98; N, 4.81. Found: C, 42.85;
H, 3.94; N, 4.78.
Synthesis of fac-[Pt{CH2C(O)Me}3(CNtBu)(bpy)]OTf (8). To
a suspension of complex 6 (61.6 mg, 0.11 mmol) in acetone (5
mL) were added TlOTf (40 mg, 0.11 mmol) and tBuNC (12.5 µL,
0.11 mmol). The reaction mixture was concentrated to dryness, and
the residue was extracted with CH2Cl2 (10 mL) and filtered through
Celite. The filtrate was concentrated (3 mL), and Et2O (10 mL)
was added. The resulting oil was stirred for 1 h at 0 °C, and the
resulting solid was filtered, washed with Et2O (5 mL), and air-
dried to give 8 as a yellow solid. Yield: 54 mg, 65%. Mp: 122
°C. ΛM (acetone, 4.9 × 10-4 mol L-1): 124 Ω-1 cm2 mol-1. IR
Synthesis of fac-[Pt{CH2C(O)Me}3Cl(bpy)] (6). Method a. To
a suspension of 1‚K (40 mg, 0.05 mmol) in acetone (5 mL) was
added bpy (28 mg, 0.18 mmol), and the mixture was stirred for 6
h and filtered. The filtrate was concentrated (0.5 mL), and addition
of Et2O (10 mL) gave a suspension, which was filtered, and the
solid was washed with Et2O (5 mL) and air-dried to give 6. Yield:
43 mg, 85%.
1
(Nujol, cm-1): ν(CN) 2232, ν(CO) 1661. H NMR (400 MHz,
Method b. To a suspension of [Pt{CH2C(O)Me}2(bpy)] (205
mg, 0.45 mmol) in acetone (40 mL) was added [HgCl{CH2C(O)-
Me}] (150 mg, 0.51 mmol), and the reaction mixture was refluxed
for 24 h. The resulting suspension was filtered through Celite, the
filtrate was concentrated (3 mL), and Et2O (20 mL) was added.
The suspension was filtered, and the solid was recrystallized from
CH2Cl2/Et2O to give 6 as a yellow solid. Yield: 130 mg, 50%.
CDCl3): δ 8.95 (m, 4 H, CH, bpy), 8.39 (m, 2 H, CH, bpy), 7.87
(m, 2 H, CH, bpy), 3.34 (HA, AB system, 2 H, CH2 trans to bpy,
2
1JHH ) 12 Hz, JHPt ) 101 Hz), 3.19 (HB, AB system, 2 H, CH2
trans to bpy, 1JHH ) 12 Hz, 2JHPt ) 59 Hz), 2.36 (s, 6 H, MeC(O)
trans to bpy), 2.23 (s, 2 H, CH2 trans to tBuNC, 2JHPt ) 77.4 Hz),
1.26 (s, 9 H, tBu), 1.24 (s, 3 H, MeC(O) trans to tBuNC). 13C{1H}
2
NMR (100.81 MHz, CDCl3): δ 211.1 (CO trans to bpy, JCPt
)
t
2
Method c. To a solution of [Pt{CH2C(O)Me}2(bpy)] (93 mg,
0.20 mmol) in CH2Cl2 (7 mL) was added chloroacetone (0.5 mL,
6.20 mmol). The mixture was stirred at 90 °C for 62 h in a Carius
tube and, after cooling, filtered through Celite. The filtrate was
concentrated (2 mL), and addition of Et2O (15 mL) gave a
suspension that was filtered off, washed with Et2O (5 mL), and
air-dried to give complex 6 as a yellow solid. Yield: 80 mg, 73%.
Mp: 192-195 °C. IR (Nujol, cm-1): ν(CO) 1675, 1636; ν(PtCl)
35.3 Hz), 210.4 (CO trans to BuNC, JCPt ) 34.7 Hz), 154.8 (C,
bpy), 148.8 (CH, bpy, JCPt ) 14.3 Hz), 142.1 (CH, bpy), 128.5
(CH, bpy, JCPt ) 15.9 Hz), 126.5 (CH, bpy, JCPt ) 10.0 Hz), 59.6
(CMe3), 32.1 (MeC(O) trans to tBuNC), 31.3 (MeC(O) trans to bpy,
3JCPt ) 9.5 Hz), 29.3 (CH2 trans to BuNC, JCPt ) 482 Hz), 24.5
t
1
(CH2 trans to bpy, JCPt ) 595 Hz). 195Pt{1H} NMR (86.18 MHz,
1
CDCl3): δ -2670. Anal. Calcd for C25H32F3N3O6PtS: C, 39.79;
H, 4.27; N, 5.57; S, 4.25. Found: C, 39.66; H, 4.49; N, 5.62; S,
4.28. Single crystals of 8 were obtained by slow diffusion of Et2O
into an acetone solution of 8.
1
273. H NMR (400 MHz, CDCl3): δ 9.60-9.55 (m, 2 H, bpy),
8.20 (m, 2 H, bpy), 8.10-8.06 (m, 2 H, bpy), 7.74-7.71 (m, 2 H,
2
bpy), 3.62 (HA, AB system, 2 H, CH2 trans to bpy, J
) 8.8
HAHB
Synthesis of mer-[Pt{CH2C(O)Me}Cl3(bpy)] (9). To a suspen-
sion of [Pt{CH2C(O)Me}Cl(bpy)] (57 mg, 0.13 mmol) in CH2Cl2
(3 mL) was added PhICl2 (40 mg, 0.15 mmol), and the resulting
yellow suspension was filtered through Celite. The filtrate was
concentrated (2 mL), Et2O (10 mL) was added, and the suspension
was filtered off. The solid was washed with Et2O (5 mL) and air-
dried to give 9 as a yellow solid. Yield: 46 mg, 70%. Mp: 131-
134 °C. IR (Nujol, cm-1): ν(CO) 1673, ν(PtCl) 347. 1H NMR (400
MHz, CDCl3): δ 9.81 (m, 1 H, CH, bpy, 3JHPt ) 30 Hz), 9.63 (m,
1 H, CH, bpy), 8.20-8.25 (m, 2 H, CH, bpy), 7.84-7.88 (m, 2 H,
Hz, 2J Pt ) 93 Hz), 3.56 (HB, AB system, 2 H, CH2 trans to bpy,
HA
2
2JH H ) 8.8 Hz, JH Pt ) 97 Hz), 2.57 (s, 3 H, CH2 trans to Cl,
B
A
B
2JHPt ) 91.6 Hz), 2.27 (s, 3 H, Me trans to bpy), 1.31 (s, 3 H, Me
trans to Cl). 13C{1H} NMR (75.45 MHz, CDCl3): δ 214.2
2
2
(MeC(O)CH2, JCPt ) 30 Hz), 210.0 (MeC(O)CH2, JCPt ) 45.2
Hz), 155.0 (C, bpy), 149.7 (CH, bpy, JCPt ) 15 Hz), 139.8 (CH,
bpy), 127.3 (CH, bpy, JCPt ) 17 Hz), 123.7 (CH, bpy, JCPt ) 11
Hz), 33.7 (MeC(O) trans to bpy), 31.4 (MeC(O) trans to Cl), 24.6
1
(CH2 trans to Cl, JCPt ) 585 Hz), 19.9 (CH2 trans to bpy, JCPt
)
581 Hz). 195Pt{1H} NMR (86.18 MHz, CDCl3): δ -2012 (s). Anal.
Calcd for C19H23ClN2O3Pt: C, 40.90; H, 4.16; N, 5.02. Found: C,
40.63; H, 4.19; N, 5.05. Single crystals of 3 were obtained by slow
diffusion of Et2O into a CH2Cl2 solution of 3.
2
CH, bpy), 4.39 (s, 2 H, CH2, JHPt ) 85 Hz), 2.34 (s, 3 H, Me).
13C{1H} NMR (100.81 MHz, CDCl3): δ 214.2 (CO), 155.4 (C,
bpy), 153.0 (C, bpy), 151.6 (CH, bpy), 147.9 (CH, bpy), 141.2
(CH, bpy), 140.7 (CH, bpy), 129.0 (CH, bpy, JCPt ) 31 Hz), 128.2

Platinum(IV) Acetonyl Complexes
Organometallics, Vol. 25, No. 18, 2006 4407
(CH, bpy, JCPt ) 13 Hz), 124.1 (CH, bpy, JCPt ) 21 Hz), 123.6
CDCl3): δ 9.49-9.43 (m, 2 H, CH, bpy), 7.91-7.86 (m, 2 H, CH,
bpy), 7.71-7.68 (m, 2 H, CH, bpy), 7.65-7.61 (m, 2 H, CH, bpy),
7.22-7.17 (m, 1 H, Ph), 6.84-6.82 (m, 4 H, Ph), 3.72 (HA, AB
1
(CH, bpy), 32.6 (Me), 26.0 (CH2, JCPt ) 458.7 Hz). 195Pt{1H}
NMR (86.18 MHz, CDCl3): δ -937 (br). Anal. Calcd for C13H13-
Cl3N2OPt: C, 30.34; H, 2.55; N, 5.44. Found: C, 30.23; H, 2.46;
N, 5.43. Single crystals of 9 were obtained by slow diffusion of
Et2O into a CH2Cl2 solution of 9.
1
2
system, 2 H, MeC(O)CH2, JHH ) 8.2 Hz, JHPt ) 94.1 Hz), 3.69
1
2
(HB, AB system, 2 H, MeC(O)CH2, JHH ) 8.2 Hz, JHPt ) 98.6
2
Hz), 3.20 (s, 2 H, PhC(O)CH2, JHPt ) 91.2 Hz), 2.33 (s, 6 H,
Synthesis of [OC-6-43]-[Pt{CH2C(O)Me}2(Me)I(bpy)] (11). To
a solution of [Pt{CH2C(O)Me}2(bpy)] (80 mg, 0.17 mmol) in CH2-
Cl2 (2 mL) was added MeI (21.5 µL, 0.35 mmol). After 14 h the
solution was concentrated (0.5 mL) and cooled for 1 h in a water/
ice bath. The suspension was filtered and the solid washed with
Et2O (2 mL) and air-dried to give 11 as a pale yellow solid. Yield:
30 mg, 30%. A second crop of 11 was obtained by addition of
Et2O (10 mL) to the filtrate, but it contained traces of 12 as an
Me). 13C{1H} NMR (75.45 MHz, CDCl3): δ 214.6 (MeC(O)CH2,
2JCPt ) 31 Hz), 200.9 (PhC(O)CH2, 2JCPt ) 48 Hz), 154.8 (C, bpy,
JCPt ) 5 Hz), 149.5 (CH, bpy, JCPt ) 14 Hz), 139.2 (CH, bpy),
137.8 (Ph), 131.9 (Ph), 127.7 (Ph), 127.2 (CH, bpy, JCPt ) 17 Hz),
126.6 (Ph), 123.0 (CH, bpy, JCPt ) 11 Hz), 33.8 (Me), 21.3 (PhC-
(O)CH2, 1JCPt ) 568 Hz), 19.6 (MeC(O)CH2, 1JCPt ) 574 Hz). 195
-
Pt{1H} NMR (86.18 MHz, CDCl3): δ -2187. Anal. Calcd for
C24H25BrN2O3Pt: C, 43.38; H, 3.79; N, 4.22. Found: C, 43.21; H,
3.80; N, 4.20.
1
impurity. Mp: 153 °C. IR (cm-1): ν(CO) 1667. H NMR (400
MHz, CDCl3): δ 9.78 (m, 2 H, CH(6), bpy), 8.21 (m, 2 H, CH(3),
X-ray Structure Determinations. Crystals were mounted in
inert oil on glass fibers and transferred to the cold gas stream of
the diffractometer (Bruker Smart Apex CCD for 1‚C, 6, and 8 and
Siemens P4 for 9). Data were collected using monochromated Mo
KR radiation in the ω mode. Absortion corrections were based on
multi scans (program SADABS) for compounds 1‚C, 6, and 8 and
on ψ scans for compound 9. The structures were refined anisotro-
pically using the program SHELXL-97 (G. M. Sheldrick, University
of Go¨ttingen, Go¨ttingen, Germany). Hydrogen atoms were included
using rigid methyl groups or a riding model. Special features of
refinement are as follows. 1‚C: half of the crown ether is disordered
over two sites, ca. 0.57:0.43. The closeness of some atoms in the
two disordered components caused convergence to be slow.
bpy), 8.08 (m, 2 H, CH(4), bpy), 7.71 (m, 2 H, CH(5), bpy), 3.71
1
1
(HA, AB system, 2 H, CH2, JH
) 8.6 Hz, JH ) 101 Hz),
AHB
APt
3.42 (HB, AB system, 2 H, CH2, 1JH ) 8.6 Hz, 1JH Pt ) 98 Hz),
AHB
B
2.32 (s, 6 H, MeC(O)), 0.87 (s, 3 H, Me, 1JHPt ) 66 Hz). 13C{1H}
NMR (100.8 MHz, CDCl3): δ 215.2 (CO), 154.5 (C, bpy), 150.4
2
(CH(6), bpy, JCPt ) 17 Hz), 139.2 (CH(4), bpy), 127.5 (CH(5),
bpy, 3JCPt ) 17 Hz), 123.4 (CH(3), bpy, 3JCPt ) 11 Hz), 33.3 (MeC-
1
1
195
(O)), 17.9 (CH2, JCPt ) 593 Hz), 8.7 (Me, JCPt ) 588 Hz).
-
Pt{1H} NMR (86.18 MHz, CDCl3): δ -2491. Anal. Calcd for
C17H21IN2O2Pt: C, 33.62; H, 3.49; N, 4.61. Found: C, 33.40; H,
3.40; N, 4.69.
Synthesis of [OC-6-34]-[Pt{CH2C(O)Me}2(Me)I(bpy)] (12). A
solution of 11 (105 mg, 0.17 mmol) in CH2Cl2 (10 mL) was heated
at 70 °C for 24 h and then filtered through Celite. The filtrate was
concentrated (ca. 1 mL), Et2O (15 mL) was slowly added, and the
resulting suspension was filtered off. The solid was air-dried to
give 12 as a yellow solid. Yield: 70 mg, 70%. Mp: 144-147 °C.
Crystallographic data for complexes 1‚C, 6, 8, and 9 are given
in Table 1.
1
IR (Nujol, cm-1): ν(CO) 1665. H NMR (400 MHz, CDCl3): δ
Results and Discussion
3
9.41 (m, 1 H, H6, py trans to Me, JHPt ) 6.8 Hz), 8.87 (m, 1 H,
3
H6, py trans to acetonyl, JHPt ) 18.1 Hz), 8.24 (m, 2 H, H3 py
Reactivity of [Hg{CH2C(O)Me}2] toward K[PtCl3(C2H4)].
Synthesis of Q[Pt2{CH2C(O)Me}6(µ-Cl)3] (Q ) K (1‚K),
K(18-C-6) (1‚C)) and cis-(Me4N)[Pt{CH2C(O)Me}Cl2(η2-
CH2dCH2)] (2‚NMe4). The attempts to transmetalate an
acetonyl group from [Hg{CH2C(O)Me}2] to Pt(II) by reacting
it with (NMe4)2[PtCl4], [K(18-C-6)]2[PtCl4], [PtCl2(PhCN)2], or
(NMe4)2[Pt2Cl6] under different reaction conditions failed, since
only complex mixtures formed or no reaction took place.
However, [Hg{CH2C(O)Me}2] and K[PtCl3(C2H4)] react at
room temperature in a 2:1 molar ratio to give a gray precipitate,
from which K[Pt2{CH2C(O)Me}6(µ-Cl)3] (1‚K) was isolated as
a colorless and poorly soluble compound after washing with
CH2Cl2, to separate the other reaction product [Hg{CH2C(O)-
Me}Cl], and extracting with hot MeCN, to remove elemental
mercury. Using different solvents and conditions, 1‚K always
crystallized as small crystals not suitable for a single-crystal
X-ray diffraction study. In similar cases, it proved very
convenient to try to solve the structure using X-ray powder
diffraction (XRPD).17 With the aid of ab initio XRPD methods,
the structure of complex 1‚K was eventually solved (Scheme
1).10 Incidentally, we originally thought of a cubane [Pt4{CH2C-
(O)Me}12(µ3-Cl)4] species, in agreement with its reactivity
toward bpy (it gives [Pt{CH2C(O)Me}3Cl(bpy)] the single-
crystal structure of which was determined; see below), elemental
trans to acetonyl and H3 py trans to Me), 8.11-8.05 (m, 2 H, H4
py trans to acetonyl and H4 py trans to Me), 7.71-7.64 (m, 2 H,
H5 py trans to acetonyl and H5 py trans to Me), 3.62 (HA, AB
1
2
system, 2 H, CH2 trans to bpy, JHH ) 7.6 Hz, JHPt ) 104 Hz),
3.30 (HB, AB system, 2 H, CH2 trans to bpy, 1JHH ) 7.6 Hz, 2JHPt
1
) 96 Hz), 2.67 (HA, AB system, 2 H, CH2 trans to I, JHH ) 6.8
Hz, 2JHPt ) 93 Hz), 2.60 (HB, AB system, 2 H, CH2 trans to I, 1JHH
) 6.8 Hz, 2JHPt ) 93 Hz), 2.31 (s, 3 H, MeC(O) trans to bpy), 1.88
2
(s, 3 H, Me, JHPt ) 67.8 Hz), 1.39 (s, 3 H, MeC(O) trans to I).
13C{1H} NMR (100.8 MHz, CDCl3): δ 215.3 (CO, 2JCPt ) 33 Hz),
2
209.3 (CO, JCPt ) 48 Hz), 155.1 (C, bpy), 154.7 (C, bpy), 149.2
(C6, py trans to Me, 2JCPt ) 12 Hz), 147.0 (C6, py trans to acetonyl,
2JCPt ) 14 Hz), 139.5 (C4 py trans to Me or acetonyl), 139.2 (C4
py trans to Me or acetonyl), 127.1 (C5 py trans to Me or acetonyl,
3
3JCPt ) 14 Hz), 126.6 (C5 py trans to Me or acetonyl, JCPt ) 18
Hz), 124.0 (C3 py trans to Me or acetonyl, 3JCPt ) 11.5 Hz), 123.6
(C3 py trans to Me or acetonyl, 3JCPt ) 9.2 Hz), 33.7 (CH2 trans to
I, 1JCPt ) 550.1 Hz), 32.6 (MeC(O) trans to N), 31.4 (MeC(O) trans
to I), 19.1 (CH2 trans to N, 1JCPt ) 540.7 Hz), -4.05 (Me, 1JCPt
)
597 Hz). 195Pt{1H} NMR (86.18 MHz, CDCl3): δ -2692. Anal.
Calc for C17H21IN2O2Pt: C, 33.62; H, 3.49; N, 4.61. Found: C,
33.92; H, 3.50; N, 4.58.
Synthesis of [OC-6-33]-[Pt{CH2C(O)Me}2{CH2C(O)Ph}Br-
(bpy)] (13). To a solution of [Pt{CH2C(O)Me}2(bpy)] (123 mg,
0.26 mmol) in CH2Cl2 (4 mL) was added BrCH2C(O)Ph (105
mg, 0.53 mmol). The reaction mixture was stirred for 32 h and
then filtered through Celite. The filtrate was concentrated (ca. 1
mL), and Et2O (10 mL) was slowly added to give a suspension,
which was filtered off. The yellow solid was air-dried and
recrystallized in CH2Cl2/Et2O. Yield: 131 mg, 75%. Mp: 173-
175 °C. IR (Nujol, cm-1): ν(CO) 1667, 1645. 1H NMR (300 MHz,
(17) Masciocchi, N.; Sironi, A. J. Chem. Soc., Dalton Trans. 1997, 4643.
Masciocchi, N.; Ragaini, F.; Sironi, A. Organometallics 2002, 21, 3489.
Vicente, J.; Gil-Rubio, J.; Bautista, D. Inorg. Chem. 2001, 40, 2636. Vicente,
J.; Gil-Rubio, J.; Bautista, D.; Sironi, A.; Masciocchi, N. Inorg. Chem. 2004,
43, 5665.

4408 Organometallics, Vol. 25, No. 18, 2006
Table 1. Crystallographic Data for Complexes 1‚C, 6, 8, and 9
Vicente et al.
1‚C
6
8
9
formula
Mr
C30H54Cl3KO12Pt2
1142.36
C19H23ClN2O3Pt
557.93
C25H32F3N3O6PtS
C13H13Cl3N2OPt
754.69
514.69
needle
cryst habit
cryst size (mm)
cryst syst
space group
cell constants
a, Å
Block
needle
lath
0.32 × 0.28 × 0.08
triclinic
0.45 × 0.28 × 0.17
monoclinic
P21/n
0.37 × 0.15 × 0.08
monoclinic
P21/n
0.22 × 0.16 × 0.06
triclinic
P1h
P1h
16.3432(8)
13.3360(7)
19.0526(9)
7.7305(5)
27.1799(19)
9.7153(7)
10.7533(6)
11.5279(6)
12.4871(7)
89.267(2)
72.360(2)
78.155(2)
1441.71(14)
2
6.7239(8)
10.6002(7)
11.6152(11)
92.998(6)
105.748(9)
106.808(6)
755.03(13)
2
b, Å
c, Å
R, deg
â, deg
103.262(2)
111.032(1)
γ, deg
V (Å3)
4041.8(3)
4
19.05.3(2)
4
Z
λ (Å)
0.710 73
1.877
7.269
2224
100
0.710 73
1.945
7.526
1080
100
0.710 73
1.738
5.001
744
100
0.710 73
2.264
9.818
484
173
F(calcd) (Mg m-3
)
µ (mm-1
F(000)
T (K)
)
2θmax (deg)
26.37
43 594
8270
27.10
20 958
4167
26.37
16 047
5786
24.99
5282
2641
no. of rflns measd
no. of indep rflns
transmissions
Rint
0.3713-0.1384
0.0271
0/434
0.5843-0.1672
0.0283
6/238
0.6904-0.2975
0.9578-0.3865
0.0350
0.0193
0/182
0.0585
0.0237
0.996
1.433
no. of restraints/params
Rw(F2, all rflns)
R(F, > 4σ(F))
S
263/358
0.0713
0.0303
1.134
2.478
0.0537
0.0217
1.055
0.0509
0.0224
1.187
max ∆F (e Å-3
)
1.341
1.391
Scheme 1
C), which, unlike 1‚K, is soluble in most common organic
solvents. A single-crystal X-ray diffraction study of 1‚C shows
the anion to be the same as that in 1‚K and thus proves the
suitability of the previous X-ray powder diffraction study.10
The formation of 1‚K involves both the transmetalation of
the acetonyl group and the oxidation of Pt(II) to Pt(IV). A study
using different molar ratios and reaction times was carried out
in order to elucidate the mechanism of this process. The 1:1
reaction was followed by 1H NMR in d6-acetone. After 15 min,
the spectrum of the reaction mixture showed the presence of
[PtCl3(C2H4)]-, [Hg{CH2C(O)Me}Cl], traces of 1‚K, and the
platinum complex 2‚K, containing the acetonyl group and
ethylene. The presence of [Hg{CH2C(O)Me}2] could not be
detected, since the resonances of the methylene and methyl
protons overlap with those of [PtCl3(C2H4)]- and d6-acetone,
respectively. After 30 min, the spectrum showed the presence
of 2‚K and [Hg{CH2C(O)Me}Cl] and only traces of [PtCl3-
(C2H4)]- and 1‚K. The complex 2‚K could not be separated
from the other reaction product [Hg{CH2C(O)Me}Cl] when the
reaction was repeated on a preparative scale. In similar
circunstances, we have solved this problem by adding an excess
of (Me4N)Cl to the reaction mixture.19 The use of this reagent
has a double purpose: (i) to symmetrize12,20 [Hg{CH2C(O)-
Me}Cl], allowing us to recover half of [Hg{CH2C(O)Me}2]
(Scheme 1) and work with a [Pt]:[Hg] ) 1:0.5 molar ratio, and
(ii) to produce [HgCl3]- salts that can be separated, along with
the excess of (Me4N)Cl, from the reaction mixture, because both
are insoluble in CH2Cl2. This transmetalation/symmetrization
analyses, NMR, IR and ESI MS data, and in analogy with most
known PtIV(alkyl) complexes [Pt4R12X4] (R ) Me, Et, X )
halogen).18
The reaction between 1‚K and 18-crown-6 (18-C-6) (1:1.5
molar ratio) gives [K(18-C-6)][Pt2{CH2C(O)Me}6(µ-Cl)3] (1‚
(19) Vicente, J.; Chicote, M. T.; Bermu´dez, M. D.; Solans, X.; Font-
Altaba, M. J. Chem. Soc., Dalton Trans. 1984, 557. Vicente, J.; Chicote,
M. T.; Martin, J.; Jones, P. G.; Fittschen, C.; Sheldrick, G. M. J. Chem.
Soc., Dalton Trans. 1986, 2215. Vicente, J.; Arcas, A.; Jones, P. G.; Lautner,
J. J. Chem. Soc., Dalton Trans. 1990, 451. Vicente, J.; Abad, J. A.; Lahoz,
F. J.; Plou, F. J. J. Chem. Soc., Dalton Trans. 1990, 1459. Vicente, J.;
Arcas, A.; Chicote, M. T. J. Organomet. Chem. 1983, 252, 257. Vicente,
J.; Arcas, A.; Ga´lvez-Lo´pez, M. D.; Jones, P. G. Organometallics 2004,
23, 3521.
(18) Allmann, R.; Kucharczyk, D. Z. Kristallogr. 1983, 165, 227. Donath,
H.; Avtomonov, E. V.; Sarraje, I.; Vondahlen, K. H.; Elessawi, M.; Lorberth,
J.; Seo, B. S. J. Organomet. Chem. 1998, 559, 191. Ebert, K. H.; Massa,
W.; Donath, H.; Lorberth, J.; Seo, B. S.; Herdtweck, E. J. Organomet. Chem.
1998, 559, 203. Hargreaves, R. N.; Truter, M. R. J. Chem. Soc. A 1971,
90. Massa, W.; Baum, G.; Seo, B. S.; Lorberth J. Organomet. Chem. 1988,
352, 415. Rundle, R. E.; Sturdivant, J. H. J. Am. Chem. Soc. 1947, 69,
1561.
(20) Vicente, J.; Abad, J. A.; Shaw, K. F.; Gil-Rubio, J.; Ram´ırez de
Arellano, M. C.; Jones, P. G. Organometallics 1997, 16, 4557.

Platinum(IV) Acetonyl Complexes
Scheme 2
Organometallics, Vol. 25, No. 18, 2006 4409
followed by removal of KCl, gives the neutral complex fac-
[Pt{CH2C(O)Me}3Cl(CNR)2] (R ) tBu (4), Xy (5)) or fac-[Pt-
{CH2C(O)Me}3Cl(N∧N)] (N∧N ) bpy (6), phen (7)), respec-
tively. Complexes 4 and 5 are very soluble in organic solvents,
even in n-pentane. To isolate them, it was necessary to evaporate
the solvent, to wash the residue with the minimum volume of
n-pentane to remove the excess isocyanide, and to maintain the
residue under vacuum for 24 h. In this way, 4 or 5 was obtained
as a pale yellow solid or oil, respectively. The reaction of 6
t
with TlOTf and BuNC in a 1:1:1 molar ratio gives fac-[Pt-
{CH2C(O)Me}3(CNtBu)(bpy)]OTf (8; Scheme 2). The analo-
gous reaction of 7 and XyNC led to the formation of
[Pt{CH2C(O)Me}3(CNXy)(phen)]OTf, which could not be
isolated analytically pure; however, its 1H NMR spectrum is in
agreement with a structure similar to that proposed for 8.
Oxidative Addition Reactions. One of the most widely used
methods for the synthesis of Pt(IV) complexes is the oxidative
addition of halogens or alkyl/acyl halides to Pt(II) derivatives.21
Despite the fact that the reactivity of alkyl platinum(II)
complexes with alkyl halides has been widely studied, only two
examples of oxidative addition of an haloketone to a platinum-
(II) complex to give a ketonyl Pt(IV) complex have been
reported.5,7 Both are monoacetonyl derivatives, and only one is
an acetonyl complex.7 This moved us to apply the oxidative
addition reaction as a method to synthesize mono-, bis-, and
tris(ketonyl) Pt(IV) complexes by reacting our complexes2 [Pt-
{CH2C(O)Me}2(bpy)] and [Pt{CH2C(O)Me}Cl(bpy)] with dif-
ferent substrates (PhICl2,16 as a solid surrogate of chlorine, MeI,
or haloketones). Thus, the reaction between [Pt{CH2C(O)Me}-
Cl(bpy)] and PhICl2 gives the Pt(IV) complex mer-[Pt{CH2C-
(O)Me}Cl3(bpy)] (9; Scheme 3). PhICl2 must be added in small
excess (1:1.1) to ensure the total conversion of the Pt(II)
complex. The reaction of [Pt{CH2C(O)Me}2(bpy)] with PhICl2
in a 1:1.2 molar ratio gives the product of the trans addition of
two chloro ligands: [OC-6-13]-[Pt{CH2C(O)Me}2Cl2(bpy)]
(10). However, the product could not be obtained in analytically
pure form, even after several recrystallizations. Although several
isomers are possible, the IR and NMR spectra agree with the
proposed structure (see Scheme 3 and the Supporting Informa-
tion). We have recently reported the use of PhICl2 to oxidize
Pt(II) to Pt(IV) complexes.22
The reaction of [Pt{CH2C(O)Me}2(bpy)] with MeI at room
temperature yields the complex resulting from trans addition,
[OC-6-43]-[Pt{CH2C(O)Me}2(Me)I(bpy)] (11). This complex
slowly isomerizes in solution at room temperature to [OC-6-
34]-[Pt{CH2C(O)Me}2(Me)I(bpy)] (12). On a preparative scale,
complex 12 was obtained by warming a solution of 11 in CH2-
Cl2 at 70 °C in a Carius tube for 12 h. Similarly, [Pt{CH2C-
(O)Me}2(bpy)] reacts with PhC(O)CH2Br at room temperature
in CDCl3 to give the first mixed ketonylmetal complex, [OC-
6-33]-[Pt{CH2C(O)Me}2{CH2C(O)Ph}Br(bpy)] (13). In solu-
tion, complex 13 evolves to a mixture of complexes that could
not be separated. The complex 6 described above can also be
obtained by reacting [Pt{CH2C(O)Me}2(bpy)] with MeC(O)-
CH2Cl (90 °C in CH2Cl2) or [Pt{CH2C(O)Me}2(bpy)] with [Hg-
{CH2C(O)Me}Cl] in refluxing acetone. The latter takes place
with formation of Hg(0), and the product is obtained with traces
of the starting material that can be separated by recrystallization.
method gives the first anionic ketonyl Pt(II) complex, cis-
(Me4N)[Pt{CH2C(O)Me}Cl2(η2-CH2dCH2)] (2‚NMe4), the spec-
troscopic data of which agree with those of 2‚K. Therefore, we
propose that the first step in the synthesis of 1‚K is a
transmetalation reaction giving K[Pt{CH2C(O)Me}Cl2(η2-CH2d
CH2)] (2‚K; Scheme 1).
The 1:2 reaction between K[PtCl3(η2-CH2dCH2)] and [Hg-
1
{CH2C(O)Me}2] in d6-acetone was also followed by H NMR
spectroscopy. The initial formation of 2‚K was observed, but
its concentration decreased while the amount of 1‚K and free
CH2dCH2 increased. No other species were detected at room
temperature or below (-10 °C). We propose that, because [Hg-
{CH2C(O)Me}Cl] and 2‚K were in contact in the 1:1 reaction
and only traces of 1‚K were observed, this complex results from
the reaction of 2‚K with [Hg{CH2C(O)Me}2] through a redox
transmetalation reaction (Scheme 1). Alternatively, a normal
transmetalation reaction could lead to a unobserved Pt(II)
intermediate, K[Pt{CH2C(O)Me}2Cl(η2-CH2dCH2)] or K2[Pt-
{CH2C(O)Me}2(µ-Cl)]2, which would rapidly react with the
other reaction product, [Hg{CH2C(O)Me}Cl], to give 1‚K and
Hg through a redox transmetalation reaction. The Hg formed
is responsible for the gray color of the initial precipitate obtained
in the reaction. We have confirmed that the complex 2‚NMe4
reacts with [Hg{CH2C(O)Me}2] to give Hg and 1‚NMe4.
Reactivity of 1‚K. The complex 1‚K is a suitable precursor
for the synthesis of tris(acetonyl) Pt(IV) complexes. With neutral
or anionic ligands in organic solvents, the reactions take place
with bridge splitting and precipitation of KCl. Thus, 1‚K reacts
with (PPN)Cl to give fac-(PPN)2[Pt{CH2C(O)Me}3Cl3] (3;
Scheme 2). A slight excess of 1‚K over the stoichiometric
amount is recommended, because such an excess can be
removed, due to the insolubility of 1‚K in the reaction solvent
(CH2Cl2), while unreacted (PPN)Cl would contaminate 3 after
addition of the precipitating solvent (Et2O). The reaction of a
suspension of 1‚K in acetone with an excess of RNC or N∧N,
(21) Anderson, G. K. ComprehensiVe Organometallic Chemistry II;
Pergamon Press: New York, 1995; Vol. 9, p 431. Hartley, F. R.
ComprehensiVe Organometallic Chemistry; Pergamon Press: Oxford, U.K.,
1982; Vol. 6, p 471. Rendina, L. M.; Puddephatt, R. J. Chem. ReV. 1997,
97, 1735.
(22) Vicente, J.; Chicote, M. T.; Guerrero, R.; Vicente-Herna´ndez, I.;
Jones, P. G.; Bautista, D. Inorg. Chem. 2006, 45, 5201.

4410 Organometallics, Vol. 25, No. 18, 2006
Vicente et al.
Scheme 3
Figure 1. Ellipsoid representation of the anion of 1‚C (50%
probability). Selected bond lengths (Å) and angles (deg): Pt(1)-
C(1) ) 2.062(3), Pt(1)-C(4) ) 2.064(3), Pt(1)-C(7) ) 2.072(3),
Pt(1)-Cl(1) ) 2.4838(8), Pt(1)-Cl(3) ) 2.4961(8), Pt(1)-Cl(2)
) 2.5099(8), Pt(2)-C(10) ) 2.073(4), Pt(2)-C(13) ) 2.075(3),
Pt(2)-C(16) ) 2.062(4), Pt(2)-Cl(1) ) 2.4762(8), Pt(2)-Cl(3)
) 2.4851(8), Pt(2)-Cl(2) ) 2.5010(8), O(1)-C(2) ) 1.211(5),
O(2)-C(5) ) 1.217(4), O(3)-C(8) ) 1.211(4), O(4)-C(11) )
1.232(5), O(5)-C(14) ) 1.219(5), O(6)-C(17) ) 1.223(5), C(1)-
C(2) ) 1.488(5), C(2)-C(3) ) 1.499(6), C(4)-C(5) ) 1.498(5),
C(5)-C(6) ) 1.511(5), C(7)-C(8) ) 1.498(5), C(8)-C(9) )
1.501(5), C(10)-C(11) ) 1.488(6), C(11)-C(12) ) 1.461(6),
C(13)-C(14) ) 1.480(5), C(14)-C(15) ) 1.481(6), C(16)-C(17)
) 1.486(6), C(17)-C(18) ) 1.497(6); C(1)-Pt(1)-C(4) ) 85.79-
(14), C(1)-Pt(1)-C(7) ) 85.59(14), C(4)-Pt(1)-C(7) ) 86.25-
(14), C(4)-Pt(1)-Cl(1) ) 92.89(11), C(7)-Pt(1)-Cl(1) ) 98.80-
(10), C(1)-Pt(1)-Cl(3) ) 93.59(10), C(4)-Pt(1)-Cl(3) ) 99.14(10),
Cl(1)-Pt(1)-Cl(3) ) 82.19(3), C(1)-Pt(1)-Cl(2) ) 100.15(10),
C(7)-Pt(1)-Cl(2) ) 94.17(10), Cl(1)-Pt(1)-Cl(2) ) 81.19(3),
Cl(3)-Pt(1)-Cl(2) ) 80.59(3), C(16)-Pt(2)-C(10) ) 85.95(17),
C(16)-Pt(2)-C(13) ) 84.92(15), C(10)-Pt(2)-C(13) 95.36(15),
C(16)-Pt(2)-Cl(1) 93.52(11), C(10)-Pt(2)-Cl(1) ) 89.20(11),
C(10)-Pt(2)-Cl(3) ) 92.58(13), C(13)-Pt(2)-Cl(3) ) 99.10(10),
Cl(1)-Pt(2)-Cl(3) ) 82.56(3), C(16)-Pt(2)-Cl(2) ) 99.89(11),
C(13)-Pt(2)-Cl(2) ) 94.11(11), Cl(1)-Pt(2)-Cl(2) ) 81.52(3),
Cl(3)-Pt(2)-Cl(2) ) 80.97(3).
Crystal Structures. The crystal structure of 1‚K was solved
using ab initio X-ray powder diffraction (XRPD) methods,10
and those of 1‚C (Figure 1), 6 (Figure 2), 8 (Figure 3), and 9
(Figure 4) were solved by single-crystal X-ray diffraction
studies. For complex 13, the atom connectivity shown in Scheme
3 was established using crystals apparently suitable for an X-ray
crystallographic study. However, repeated attempts and data
collection at low temperature did not give satisfactory refinement
of the structure. All of the structures show the platinum atom
in a distorted-octahedral environment. The structures of the
anion in complexes 1‚C and 1‚K10 are analogous: two octahedra
with a common face containing the three bridging chloro ligands
(Figure 1) similar to what is observed in the Pt(II) complex
axial K(1)-O(6) distances of 2.711(3) Å, and K(2), with shorter
K(2)-O(1) distances of 2.625(3) Å. Both are shorter than the
equatorial distance (2.755(6)-2.841(3) Å). The coordination of
the acetonyl ligand to K+ does not cause the lengthening of the
C-O bond distances (1.223(5) and 1.211(5) Å) with respect to
those in the terminal acetonyl ligands (1.232(5)-1.211(4) Å),
and all are within the range observed for complexes 6, 8, and
9 (1.228(7)-1.212(5) Å) and for the ketonyl platinum(II)
complexes reported in the literature (1.25(3)-1.226(12) Å).2,25,26
The oxidation state of the metal has little effect on the Pt-C
distances, since the range in 1‚C, 6, 8, and 9 (2.100(4)-2.063-
(4) Å) is similar to that found in acetonyl platinum(II)
compounds (2.116(8)-2.03(4) Å).2,25,26 The same effect was
observed for methyl platinum(II) and platinum(IV) complexes.27
In 9, the Pt-Cl bond distance trans to N (2.3073(13) Å) is
shorter than the two mutually trans Pt-Cl bond distances
(2.3178(14), 2.3124(13) Å). These three distances are shorter
n
[Pt2{η4-C4 Pr4}2(µ-Cl)3]+ 23 and in the well-known isoelectronic
[Re2(µ-Cl)3(CO)6]-.24 The six Pt-C bond distances in 1‚C are
not significantly different (range 2.075(3)-2.062(4) Å), while
the Pt(1)-Cl bond lengths are in a wider range (2.4762(8)-
2.5099(8) Å). Due to the intrinsic low precision of power
diffraction, the corresponding values found in 1‚K (Pt-C )
2.20(2) Å and PtCl ) 2.533(7) Å) are barely comparable.10 In
1‚C, a hexagonal-bipyramidal environment for K is reached with
the oxygen atoms of 18-C-6 in equatorial positions and two
oxygen atoms of two acetonyl ligands of different anions in
axial positions; this results in the formation of a chain (Figure
5). The K cations adopt two different dispositions: K(1), with
(25) Falvello, L. R.; Garde, R.; Miqueleiz, E. M.; Tomas, M.; Urriola-
beitia, E. P. Inorg. Chim. Acta 1997, 264, 297.
(23) Canziani, F.; Galimberti, F.; Garlaschelli, L.; Malatesta, M. C.;
Albinati, A. Gazz. Chim. Ital. 1982, 112, 323.
(24) Davis, R. L.; Baenziger, N. C. Inorg. Nucl. Chem. Lett. 1977, 13,
475.
(26) Suzaki, Y.; Yagyu, T.; Yamamura, Y.; Mori, A.; Osakada, K.
Organometallics 2002, 21, 5254. Lai, S. W.; Chan, M. C. W.; Cheung, K.
K.; Che, C. M. Inorg. Chem. 1999, 38, 4262.
(27) Kettle, S. F. A. J. Chem. Soc. 1965, 5737.

Platinum(IV) Acetonyl Complexes
Organometallics, Vol. 25, No. 18, 2006 4411
Figure 2. Ellipsoid representation of 6 (50% probability). Selected
bond lengths (Å) and angles (deg): Pt(1)-C(11) ) 2.078(3), Pt-
(1)-C(14) ) 2.090(3), Pt(1)-C(17) ) 2.095(3), Pt(1)-N(2) )
2.122(3), Pt(1)-N(1) ) 2.135(3), Pt(1)-Cl(1) ) 2.4338(8), O(1)-
C(12) ) 1.218(4), O(2)-C(15) ) 1.214(5), O(3)-C(18) ) 1.219-
(4), C(11)-C(12) ) 1.498(5), C(12)-C(13) ) 1.503(5), C(14)-
C(15) ) 1.516(5), C(15)-C(16) ) 1.512(5), C(17)-C(18) )
1.494(5), C(18)-C(19) ) 1.510(5); C(11)-Pt(1)-C(14) ) 88.87-
(13), C(11)-Pt(1)-C(17) ) 86.43(13), C(14)-Pt(1)-C(17) )
87.11(13), C(14)-Pt(1)-N(2) ) 97.02(12), C(17)-Pt(1)-N(2) )
87.20(12), C(11)-Pt(1)-N(1) ) 96.77(12), C(17)-Pt(1)-N(1) )
96.49(11), N(2)-Pt(1)-N(1) ) 77.79(10), C(11)-Pt(1)-Cl(1) )
93.89(9), C(14)-Pt(1)-Cl(1) ) 92.31(9), N(2)-Pt(1)-Cl(1) )
92.55(8), N(1)-Pt(1)-Cl(1) ) 84.06(7).
Figure 4. Ellipsoid representation of 9 (50% probability). Selected
bond lengths (Å) and angles (deg): Pt(1)-N(2) ) 2.042(4), Pt-
(1)-C(1) ) 2.089(6), Pt(1)-N(1) ) 2.136(5), Pt(1)-Cl(3) )
2.3073(13), Pt(1)-Cl(2) ) 2.3124(13), Pt(1)-Cl(1) ) 2.3178(14),
O(1)-C(2) ) 1.228(7), C(1)-C(2) ) 1.479(8), C(2)-C(3) )
1.505(8); N(2)-Pt(1)-C(1) ) 96.4(2), N(2)-Pt(1)-N(1) ) 78.76-
(17), C(1)-Pt(1)-Cl(3) ) 89.15(16), N(1)-Pt(1)-Cl(3) ) 95.97-
(12), N(2)-Pt(1)-Cl(2) ) 87.03(13), C(1)-Pt(1)-Cl(2) ) 95.44-
(16), N(1)-Pt(1)-Cl(2) ) 91.82(12), Cl(3)-Pt(1)-Cl(2) ) 90.27(5),
N(2)-Pt(1)-Cl(1) ) 92.42(13), C(1)-Pt(1)-Cl(1) ) 85.19(16),
N(1)-Pt(1)-Cl(1) ) 87.50(12), Cl(3)-Pt(1)-Cl(1) ) 90.23(5).
Figure 3. Ellipsoid representation of 8 (50% probability). Selected
bond lengths (Å) and angles (deg): Pt(1)-C(10) ) 2.023(4), Pt-
(1)-C(7) ) 2.069(4), Pt(1)-C(1) ) 2.091(4), Pt(1)-C(4) ) 2.100-
(4), Pt(1)-N(1) ) 2.127(3), Pt(1)-N(2) ) 2.147(3), N(3)-C(10)
) 1.145(5), O(1)-C(2) ) 1.227(5), O(2)-C(5) ) 1.224(5), O(3)-
C(8) ) 1.212(5), C(1)-C(2) ) 1.501(6), C(2)-C(3) ) 1.499(6),
C(4)-C(5) ) 1.478(6), C(5)-C(6) ) 1.512(6), C(7)-C(8) )
1.509(6), C(8)-C(9) ) 1.499(6); C(10)-Pt(1)-C(7) ) 98.63(17),
C(10)-Pt(1)-C(1) ) 93.10(16), C(7)-Pt(1)-C(1) ) 87.50(17),
C(7)-Pt(1)-C(4) ) 83.03(17), C(1)-Pt(1)-C(4) ) 87.33(17),
C(10)-Pt(1)-N(1) ) 90.10(14), C(7)-Pt(1)-N(1) ) 97.99(15),
C(4)-Pt(1)-N(1) ) 89.29(15), C(10)-Pt(1)-N(2) ) 83.80(15),
C(1)-Pt(1)-N(2) ) 97.15(15), C(4)-Pt(1)-N(2) ) 94.51(15),
N(1)-Pt(1)-N(2) ) 77.18(13).
Figure 5. Ellipsoid representation of anions and cations in 1‚C
(50% probability). Selected K-O bond lengths (Å): K(1)-O(6)
) 2.711(3), K(1)-O18-C-6 (range) ) 2.755(6)-2.825(9), K(2)-
O(1) ) 2.625(3), K(2)-O18-C-6 (range) ) 2.806(2)-2.841(3).
1‚C, the PtCl bond distances (2.4762(8)-2.5099(8) Å) are much
longer than those in 6 and 9, mainly because they are bridging.
In complexes 6, 8, and 9, the Pt-N bond distance trans to the
acetonyl group (2.122(3)-2.147(3) Å) is longer than that
reported for acetonyl platinum(II) complexes (2.082(3), 2.091-
(4) Å),2,25 probably because of the greater π-acceptor character
of bpy in acetonyl Pt(II) complexes.
Spectroscopic Properties. The 1H and 13C{1H} NMR spectra
of all complexes are in agreement with the structures shown in
Schemes 1-3. For complex 10, these spectra would also agree
with a trans arrangement of the acetonyl ligands, but we discard
this geometry on the basis of the great transphobia28 between
than those trans to the acetonyl ligand in 6 (2.4338(8) Å),
showing that the trans influence decreases in the series acetonyl
> Cl > N-donor ligand. For the same reason, the Pt-N bond
trans to Cl (2.042(4) Å) in complex 9 is shorter than that trans
to the acetonyl group in 6, 8, or 9 (2.122(3)-2.147(3) Å). In

4412 Organometallics, Vol. 25, No. 18, 2006
Vicente et al.
two C-donor ligands.28,29 In fact, all Pt(IV) complexes [PtR2X2-
(L)(L′)] (R ) C-donor ligand, X ) any halogen, L, L′ ) any
ligand, except C-donor) contain the R ligands mutually cis.4,30,31
The 1H NMR spectrum of 12 shows the nonequivalence of the
halves of the bpy ligand, and the methylene protons as two AB
systems, with 195Pt satellites. This is only compatible with two
geometries having the Me group trans to bpy or to one acetonyl
group. The latter can be discarded, because the Me ligand has
an NOE effect only with the H6 proton of bpy. This is a new
example of the preference of two C-donor ligands to be cis
because of their mutual transphobia.28,29
attributed to the paramagnetic component of the shielding
constant, because the greater thermodynamic stability of 12 must
be associated with a larger excitation energy. The platinum
nucleus in the Pt(II) complex [Pt{CH2C(O)Me}2(bpy)] (-3351
ppm) is, as expected, more shielded than that in its Pt(IV)
derivatives 6 and 10-13 (range -1500 to -2692 ppm). The
195Pt{1H} spectrum of complex 4 shows a quintuplet at -3343
ppm due to the coupling with the 14N nuclei of the equivalent
tBuNC ligands. Replacement of bpy in 6 (-2012 ppm) or 7
(-2017 ppm) by isocyanide (4, -3343 ppm; 5, -3307 ppm)
increases the shielding of the 195Pt nuclei. This effect has been
reported previously.32
1
The H NMR spectra of complexes 6-8 and 12 show the
Me protons of one acetonyl (1.39-1.08 ppm) shielded by ca. 1
ppm with respect to the others (2.25-2.34 ppm) or to those in
complexes 4 and 5 (2.34-2.25 ppm), due to the induced
paramagnetic anisotropy of the bpy and phen ligands.
The chloro complexes show band(s) assignable to ν(PtCl)
modes at different wavenumbers depending on the nature of
the ligands in trans positions, the coordination mode of the
chloro ligand, and the charge of the complex. Thus, in
complexes 1, one (1‚K, 245 cm-1) or two (1‚C, 250, 232 cm-1
)
The values of δ(1H) and δ(13C) for the CH2 nuclei trans to
bpy and the corresponding δ(195Pt) values follow the order (in
ppm): 6 (3.62, 3.56; 19.9; -2012) < 10 (3.90; 21.4; -1500)
< 9 (4.39; 26.0; -937), due to the successive replacement of
bands appear in the lower energy region of the spectrum, as
expected for bridging chloro ligands trans to C-donor ligands
in an anionic complex. In complex 3 an increase in the energy
of the ν(PtCl) absorptions (265, 241(br) cm-1) is observed, due
to the terminal nature of the chloro ligands, but the shift is only
small because the complex is dianionic. In neutral complexes
containing terminal chloro ligands trans to acetonyl (4, 6, and
7), one band appears in the range 273-265 cm-1, while similar
complexes with chloro trans to ligands with low trans influence
such as chloro and bpy (9 and 10) show ν(PtCl) absorptions in
the range 347-341 cm-1. In trans-dichloroplatinum(IV) com-
plexes, characterized by X-ray diffraction studies, one band in
the region 344-360 cm-1 has been assigned.30,33 The cis
geometry of 2‚NMe4 is proposed on the basis of the IR
1
an acetonyl group by a Cl ligand. The JCPt value is greater in
complexes with the acetonyl ligand trans to Cl (585-568 Hz)
or N-donor ligands (593-541 Hz) than to ligands with greater
trans influence such as isocyanides (468-459 Hz).
As expected, the shielding of the platinum nuclei in the Pt-
(IV) complexes increases as chloro ligands are replaced by
acetonyl ligands, 9 (-937 ppm) > 10 (-1500 ppm) > 6 (-2012
ppm), or when, in complexes with three C-donor ligands and
one bpy, a chloro ligand is replaced by a bromo ligand, 6
(-2012 ppm) > 13 (-2187 ppm), or an iodo ligand, 11 (-2491
ppm), 12 (-2692 ppm). The significantly greater shielding of
12 with respect to its isomer 11 (∆ ) 200 ppm) must be
spectrum, which shows two bands at 311 and 264 cm-1
,
assignable to ν(PtCl) trans to ethylene and the acetonyl group,
respectively, in agreement with the assignment made for 3 and
the stronger trans influence of the acetonyl ligand with respect
to the ethylene ligand.
(28) Vicente, J.; Arcas, A.; Bautista, D.; Jones, P. G. Organometallics
1997, 16, 2127. Vicente, J.; Abad, J. A.; Frankland, A. D.; Ram´ırez de
Arellano, M. C. Chem. Eur. J. 1999, 5, 3066. Vicente, J.; Abad, J. A.;
Herna´ndez-Mata, F. S.; Jones, P. G. J. Am. Chem. Soc. 2002, 124, 3848.
Vicente, J.; Abad, J. A.; Mart´ınez-Viviente, E.; Jones, P. G. Organometallics
2002, 21, 4454.
The number of ν(CO) bands in the IR spectra of complexes
is usually lower than expected. Thus, while the two expected
ν(CO) bands in complexes 1 are observed in 1‚C (1686, 1682
cm-1), both are coincident in 1‚K (1689 cm-1). The other
complexes show one or two (only 6, 13) bands in the range
(29) Marshall, W. J.; Grushin, V. V. Organometallics 2003, 22, 555.
Lo´pez, C.; Caubet, A.; Pe´rez, S.; Solans, X.; Font-Bard´ıa, M. J. Organomet.
Chem. 2003, 681, 82. Jalil, M. A.; Fujinami, S.; Nishikawa, H. Dalton Trans.
2001, 1091. Fernandez-Rivas, C.; Cardenas, D. J.; Martin-Matute, B.;
Monge, A.; Gutierrez-Puebla, E.; Echavarren, A. M. Organometallics 2001,
20, 2998. Fernandez, A.; Vazquez Garcia, D.; Fernandez, J. J.; Lo´pez Torres,
M.; Suarez, A.; Castro Juiz, S.; Vila, J. M. Eur. J. Inorg. Chem. 2002,
2389. Crespo, M.; Granell, J.; Solans, X.; Fontbardia, M. J. Organomet.
Chem. 2003, 681, 143. Carbayo, A.; Cuevas, J. Y.; Garcia Herbosa, G.;
Garcia Granda, S.; Miguel, D. Eur. J. Inorg. Chem. 2001, 2361. Amatore,
C.; Bahsoun, A. A.; Jutand, A.; Meyer, G.; Ntepe, A. N.; Ricard, L. J. Am.
Chem. Soc. 2003, 125, 4212. Lohner, P.; Pfeffer, M.; Fischer, J. J.
Organomet. Chem. 2000, 607, 12. Fernandez, S.; Navarro, R.; Urriolabeitia,
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1689-1645 cm-1
.
Conclusions
We have found that acetonyl Pt(IV) complexes can be
prepared (i) by a transmetalation/oxidation reaction using [Hg-
{CH2C(O)Me}2] and K[PtCl3(C2H4)] and (ii) by oxidative
addition reactions of PhICl2, MeI, RX (R ) ketonyl, X ) Cl,
Br), or [Hg{CH2C(O)Me}Cl] to [Pt{CH2C(O)Me}Cl(bpy)] or
[Pt{CH2C(O)Me}2(bpy)]. The mechanism of the transmetala-
tion/oxidation reaction has been proved to occur in at least two
steps: formation of the anionic acetonyl Pt(II) complex K[Pt-
{CH2C(O)Me}Cl2(η2-CH2dCH2)] and a redox transmetalation
reaction leading to metallic Hg and K[Pt2{CH2C(O)Me}6(µ-
Cl)3]. The oxidative addition reactions give mono(acetonyl), the
first bis(acetonyl), and new tris(acetonyl) Pt(IV) complexes. The
last group, along with K[Pt2{CH2C(O)Me}6(µ-Cl)3] and its
neutral, anionic, and cationic substitution products, are the first
tris(ketonyl) complexes of any metal. One of them, [OC-
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Platinum(IV) Acetonyl Complexes
Organometallics, Vol. 25, No. 18, 2006 4413
Supporting Information Available: Text giving details of the
synthesisandspectroscopicpropertiesof[OC-6-13]-[Pt{CH2C(O)Me}2-
Cl2(bpy)] (10) and CIF files giving crystallographic data for 1‚C,
6, 8, and 9. This material is available free of charge via the Internet
at http://pubs.acs.org.
6-33]-[Pt{CH2C(O)Me}2{CH2C(O)Ph}Br(bpy)], is the first
mixed ketonylmetal complex.
Acknowledgment. We thank the Direccio´n General de
Investigacio´n, Ministerio de Educacio´n y Ciencia, and the
FEDER for financial support (Grant CTQ2004-05396). J.M.F.-
H. acknowledges grants from Fundacio´n Se´neca and Fundacio´n
Cajamurcia.
OM0605027