A new family of organometallic rhodium complexes with [Rh(PiPr2Ph)2] and [Rh(PiPrPh2)2] as molecular units

Article abstract of DOI:10.1002/1099-0682(200206)2002:6<1377::aid-ejic1377>3.0.co;2-d

The π-allyl complexes [Rh(η³-C₃H₅) (PR₃)₂] [PR₃ = PiPr₂Ph (4), PiPrPh₂ (5)], prepared from RhCl(C₈H₁₄)₂]₂, PR₃ and the Grignard reagent C₃H₅MgBr, react with carboxylic acids and p-toluenesulfonic acid to give the chelate compounds [Rh(κ²O₂CR′)(PR₃)₂] (8-10) and [Rh{κ²-O₂S(O)-p-Tol}(PR₃)₂] (11, 12), respectively. While the reactions of 8, 10 and 12 with CO afford the square-planar rhodium(I) complexes 13-15 with monodentate carboxylato and tosylato ligands, treatment of 8-10 and 11, 12 with H₂ leads to the formation of the octahedral dihydridorhodium(III) derivatives [RhH₂ (κ²-O₂CR′)(PR₃)₂] (16-18) and [RhH₂{κ²-O₂S(O) -p-Tol}[PR₃)₂] (19, 20). Similarly to CO, internal alkynes RC≡CCO₂Me (R = CO₂Me, Me) react with 8 and 9 by partial opening of the chelate bond to yield the π-alkyne complexes 21-23, of which 23 with R = Me is quite labile and smoothly regenerates the starting material. In contrast, the reactions of 8 and 9 with terminal alkynes HC≡CR (R = Ph, CO₂Me) afford six-coordinate alkynyl(vinyl)rhodium(III) compounds 24-26 with a different stereochemistry at the C=C double bond depending on the substituent R. From 8 and HC≡CCH(Cl)Me the octahedral allenyl complex [RhCl(CH=C=CHMe)(κ²-O₂CR′) (PiPrPh₂)₂] (27) is obtained, the molecular structure of which has been determined by X-ray crystallography. The reaction of [Rh(κ¹O₂CR) {η²-C₂(CO₂Me)₂} (PiPrPh₂)₂] (21, 22) with HC≡CPh also leads to the six-coordinate alkynyl (vinyl)rhodium(III) compounds 28, 29, which upon treatment with Me₃SiCl and thermolysis are stepwise converted into the four-coordinate π-enyne complex trans-[RhCl{η²-PhC≡CC(CO₂Me)= CHCO₂Me}(PiPrPh₂)₂] (31). The reaction of 31 with CO generates the uncoordinated substituted enyne. The rhodium(I) vinylidene complexes trans-[Rh(C≡CR′)(=C=CHR)(PiPrPh₂)₂] (36-38) were prepared in two steps from the tosylato complex 12 and terminal alkynes; they react with CO via migratory insertion to give the square-planar enynyl compounds trans-[Rh{η¹-C(C≡CR)=CHR′}(CO) (PiPrPh₂)₂] (39-41). Wiley-VCH Verlag GmbH, 69451 Weinheim, Germany, 2002.

Full text of DOI:10.1002/1099-0682(200206)2002:6<1377::aid-ejic1377>3.0.co;2-d

FULL PAPER
A New Family of Organometallic Rhodium Complexes with [Rh(PiPr2Ph)2]
and [Rh(PiPrPh2)2] as Molecular Units
Helmut Werner,*[a] Frank Kukla,[a] and Paul Steinert[a]
Dedicated to Professor Walter Siebert on the occasion of his 65th birthday
Keywords: Allyl ligands / Alkyne ligands / Vinylidene complexes / Rhodium / Phosphanes
The π-allyl complexes [Rh(η3-C3H5)(PR3)2] [PR3 = PiPr2Ph (4),
PiPrPh2 (5)], prepared from [RhCl(C8H14)2]2, PR3 and the
Grignard reagent C3H5MgBr, react with carboxylic acids and
p-toluenesulfonic acid to give the chelate compounds [Rh(κ2-
O2CRЈ)(PR3)2] (8−10) and [Rh{κ2-O2S(O)-p-Tol}(PR3)2] (11,
12), respectively. While the reactions of 8, 10 and 12 with CO
afford the square-planar rhodium(I) complexes 13−15 with
monodentate carboxylato and tosylato ligands, treatment of
8−10 and 11, 12 with H2 leads to the formation of the octa-
hedral dihydridorhodium(III) derivatives [RhH2(κ2-O2CRЈ)-
(PR3)2] (16−18) and [RhH2{κ2-O2S(O)-p-Tol}(PR3)2] (19, 20).
substituent R. From 8 and HCϵCCH(Cl)Me the octahedral
allenyl complex [RhCl(CH=C=CHMe)(κ2-O2CRЈ)(PiPrPh2)2]
(27) is obtained, the molecular structure of which has been
determined by X-ray crystallography. The reaction of [Rh(κ1-
O2CR){η2-C2(CO2Me)2}(PiPrPh2)2] (21, 22) with HCϵCPh
also leads to the six-coordinate alkynyl(vinyl)rhodium(III)
compounds 28, 29, which upon treatment with Me3SiCl and
thermolysis are stepwise converted into the four-coordinate
π-enyne
complex
trans-[RhCl{η2-PhCϵCC(CO2Me)=
CHCO2Me}(PiPrPh2)2] (31). The reaction of 31 with CO gen-
erates the uncoordinated substituted enyne. The rhodium(I)
Similarly to CO, internal alkynes RCϵCCO2Me (R = CO2Me, vinylidene
complexes
trans-[Rh(CϵCRЈ)(=C=CHR)-
Me) react with 8 and 9 by partial opening of the chelate bond
to yield the π-alkyne complexes 21−23, of which 23 with R =
Me is quite labile and smoothly regenerates the starting mat-
erial. In contrast, the reactions of 8 and 9 with terminal al-
(PiPrPh2)2] (36−38) were prepared in two steps from the tosyl-
ato complex 12 and terminal alkynes; they react with CO via
migratory insertion to give the square-planar enynyl
compounds
trans-[Rh{η1-C(CϵCR)=CHRЈ}(CO)(PiPrPh2)2]
kynes HCϵCR (R = Ph, CO2Me) afford six-coordinate alkyn- (39−41).
yl(vinyl)rhodium(III) compounds 24−26 with different ( Wiley-VCH Verlag GmbH, 69451 Weinheim, Germany,
a
stereochemistry at the C=C double bond depending on the
2002)
Introduction
recent paper, some evidence for this assumption was already
presented.[4] The present article describes preparative routes
to four-coordinate carboxylato- and tosylatorhodium(I)
complexes with PiPrPh2 and PiPr2Ph as ligands and reports
in detail on their reactivity toward internal and terminal al-
kynes.
In the context of our investigations on low-valent
organorhodium compounds,[1] we recently reported a high-
yield synthesis of the π-allyl complexes [Rh(η3-2-
C3H4R)(PiPr3)2] (R ϭ H, Me, Ph) which readily react with
Brønsted acids by cleavage of the allyl-metal bond.[2] If ter-
minal alkynes HCϵCR were used as acidic substrates, the
alkynyl(vinylidene)rhodium(I)
[Rh(CϵCR)(ϭCϭCHR)(PiPr3)2] were obtained which, in
compounds
trans-
Results and Discussion
the presence of CO or isocyanides, undergo an intramolecu-
The method recently used by us for the synthesis of
lar CϪC coupling process.[3] Since we observed that the [Rh(η3-C3H5)(PiPr3)2][2] could also be applied for the pre-
course of the reactions of rhodium(I) compounds paration of the related complexes 4 and 5 (Scheme 1). Treat-
[Rh(X)(PiPr3)2] (where X could be a carboxylate or tosyl- ment of a suspension of 1 in toluene with PiPr2Ph or
ate) with HCϵCR depends on both the anionic ligand XϪ PiPrPh2 in 1:4 molar ratio, followed by the addition of a
and the substituent R of the alkyne, we became interested solution of the Grignard reagent C3H5MgBr in ether, re-
to find out whether the nature of the phosphane would also sults in the formation of the π-allylrhodium(I) compounds
have an influence on the composition of the products. In a 4 and 5, which were isolated as yellow solids in about 80%
yield. If the violet solution, formed upon the addition of
[a]
Institut für Anorganische Chemie der Universität
PiPr2Ph or PiPrPh2 to the starting material 1 in toluene, is
dried in vacuo, the bis(phosphane)rhodium(I) derivatives 2
and 3 were obtained. These dimeric complexes are some-
Am Hubland, 97074 Würzburg, Germany
Fax: (internat.) ϩ 49-(0)931/888-4623
E-mail: helmut.werner@mail.uni-wuerzburg.de
Eur. J. Inorg. Chem. 2002, 1377Ϫ1389  WILEY-VCH Verlag GmbH, 69451 Weinheim, Germany, 2002 1434Ϫ1948/02/0606Ϫ1377 $ 20.00ϩ.50/0
1377

H. Werner, F. Kukla, P. Steinert
FULL PAPER
what less air-sensitive than the triisopropylphosphane coun-
[5]
terpart [RhCl(PiPr3)2]2 and can be stored under argon at
room temperature without decomposition. The 31P NMR
spectra of 2 and 3 show the expected doublet with a large
31P-103Rh coupling constant of ca. 198 Hz that is typical for
rhodium(I) compounds with [Rh(PR3)2] as a building block
and cis-disposed phosphane ligands.[2,4,6]
Scheme 2
um(I) derivatives [{Rh(µ-O2CR)(C2H4)2}2] and [{Rh(µ-
O2CR)(CO)2}2], respectively.[9] We assume that a chelating
bonding mode also results for the RSO3 unit in the com-
Scheme 1
Ϫ
While the reactions of 2 and 3 with a twofold excess of plexes 11 and 12, as has been confirmed for the bis(triiso-
the Grignard reagent C3H5MgBr also lead to the generation propylphosphane) compound [Rh{κ2-O2S(O)R}(PiPr3)2]
of 4 and 5, the preparative route using 1 as the precursor is (R ϭ p-Tol; Tol ϭ C6H4Me) by X-ray crystallography.[10]
more convenient. It can also be applied for the synthesis of
With regard to the mechanism of formation of 8Ϫ10 and
6 and 7 with PHiPr2 and PtBu2Me as the phosphane li- 11, 12 from the π-allyl metal precursors 4 and 5, we assume
gands. The 1H NMR spectra of the π-allylrhodium(I) com- that the primary step consists of an oxidative addition of
plexes 4 and 6 exhibit, besides the expected sets for the the acid HX to the rhodium(I) center to give the six-coord-
C3H5 protons, four resonances for the protons of the dia- inate
rhodium(III)
intermediates
[RhH(κ1-X)(η3-
stereotopic methyl groups of the PiPr2 moieties, which are C3H5)(PR3)2] (X ϭ O2CR, O3SR), which upon reductive
1
split into doublets of doublets due to 31P-1H and H-1H elimination of propene afford the products. We note that
1
coupling. Moreover, the H NMR spectrum of 6 shows a upon treatment of [Rh(η3-C3H5)(PiPr3)2] with an equimolar
doublet of triplets at δ ϭ 4.06 with a large 31P-1H coupling amount of CF3CO2H in pentane at Ϫ20 °C a stable com-
constant of 256.5 Hz that is characteristic of a P-bonded pound [RhH(κ1-O2CCF3)(η3-C3H5)(PiPr3)2] has been isol-
hydrogen atom. The observation of two distinct signals for ated which reacts at 40 °C to give [Rh(κ2-O2CCF3)(PiPr3)2]
the nuclei of the syn and the anti protons of the terminal and C3H6.[2]
allylic CH2 groups indicate that in solution at room temper-
ature the (η3-C3H5)Rh unit is rigid and does not undergo as the tosylato derivatives are quite labile and react by par-
an η3-η1-η3 rearrangement.[7]
tial opening of the chelate bond. This behavior has been
In the presence of CO, the carboxylato complexes as well
The π-allylic complexes 4 and 5 react smoothly with equi- exemplified by the preparation of the mononuclear com-
molar amounts of carboxylic acids or p-toluenesulfonic acid pounds 13Ϫ15 (Scheme 3 and 4), which were isolated as
by cleavage of the allyl-metal bond (Scheme 2). The appar- pale-yellow, almost air-stable solids in 93Ϫ98% yield. In
ently more simple synthetic method, namely the reaction of contrast to 8 and 10, the IR spectra of 13 and 14 confirm
Ϫ
2 or 3 with RCO2Na or RSO3Na, led to mixtures of prod- that the RCO2 units are coordinated in a monodentate
ucts which could not be separated by fractional crystalliza- fashion. The two phosphane ligands of 13Ϫ15 are trans-
tion or chromatographic techniques. Both the rhodium disposed, which is illustrated by the appearance of one
carboxylates 8Ϫ10 and the rhodium tosylates 11 and 12 are doublet in the 31P NMR spectra, the respective 31P-103Rh
red air-sensitive solids which, with the exception of pentane, coupling constant being significantly smaller than for the
are readily soluble in common organic solvents. The IR starting materials 8, 10 and 12 with a cis-disposed
spectra of the carboxylato compounds 8Ϫ10 display two Rh(PR3)2 moiety.
bands in the region of 1425Ϫ1445 and 1480Ϫ1510 cmϪ1
The carboxylato compounds 8Ϫ10 also react at room
assigned to the symmetric and asymmetric OCO stretching temperature with dihydrogen to give the octahedral dihydri-
modes. According to various data from the literature,[8] dorhodium(III) complexes 16Ϫ18 by oxidative addition.
Ϫ
there is no doubt that the RCO2 ligands of 8Ϫ10 are co- The white solids are much less sensitive towards air than
ordinated in a chelating and not in a bridging fashion as the rhodium(I) precursors and can be stored under argon
found for the bis(ethene)rhodium(I) and dicarbonylrhodi- for weeks. The 31P NMR spectra of 16Ϫ18 show only one
1378
Eur. J. Inorg. Chem. 2002, 1377Ϫ1389

Rhodium Complexes with [Rh(PiPr2Ph)2] and [Rh(PiPrPh2)2] as Molecular Units
FULL PAPER
amount of the alkyne at room temperature leads to an al-
most instantaneous change of color from dark red to yellow
and finally affords the products 21 and 22 (see Scheme 5)
1
in about 85% yield. The H and 31P NMR spectra of 21
and 22 are, with respect to the PiPrPh2 ligands, quite similar
to those of the carbonyl compound 13, and thus there is
no doubt that the coordination geometry around the metal
center is square planar. The IR spectra of 21 and 22 show
the ν(CϵC) stretching mode at 1810 cmϪ1 (for 21) and 1785
cmϪ1 (for 22), the decrease of about 450 cmϪ1 relative to
free C2(CO2Me)2 being in agreement with the strong π-ac-
ceptor character of the electron-poor alkyne.
Scheme 3
Scheme 5
While compound 8 does not react with MeCϵCCO2Me
in toluene at Ϫ20 °C, the corresponding reaction for 9 with
MeCϵCCO2Me under the same conditions takes place but
is reversible. Only if the reaction mixture formed after stir-
Scheme 4
resonance, indicating that the two phosphanes remain in a ring a solution of 9 and the alkyne in toluene at Ϫ20 °C
trans disposition. In the 1H NMR spectra, there is also only for 2 h is worked-up rather quickly, and the crude product
one set of signals at δ ϭ Ϫ22.0 to Ϫ22.7 for the hydride recrystallized from hexane at Ϫ78 °C, can a light yellow
ligands, which is in agreement with the proposed structure solid with the analytical composition corresponding to 23
1
shown in Scheme 3.
be isolated. The H and 31P NMR spectra (measured in
The tosylato derivatives 11 and 12 have the same reactiv- [D8]toluene at Ϫ30 °C) differ only slightly from those of 22
ity towards H2 as the carboxylato derivatives. However, the and thus deserve no further comment.
isolated dihydrido complexes 19 and 20 are less stable than
The reactions of 8 and 9 with terminal alkynes take a
16Ϫ18 and in vacuo slowly lose dihydrogen to regenerate different course to those of the same starting materials with
the starting materials 11 and 12. Therefore, it is necessary C2(CO2Me)2. Treatment of the carboxylato rhodium(I)
that they are stored at low temperature under a H2 atmo- complexes with two equiv. of phenylacetylene in toluene at
1
sphere. Since the H and 31P NMR spectroscopic data of Ϫ50 °C leads unexpectedly to the formation of the octahed-
19 and 20 are similar to those of 16Ϫ18, we assume that at ral alkynyl(vinyl)rhodium(III) compounds 24 and 25
25 °C the two possible stereoisomers rapidly interconvert (Scheme 6), which were isolated as pale-yellow, only moder-
on the NMR time scale. At Ϫ78 °C in [D8]toluene, there is ately air-sensitive solids in excellent yields. Although we at-
only a slight broadening of the single resonance in the 31P tempted to detect the supposed intermediates
1
NMR spectra, which indicates that even under these condi- [RhH(CϵCPh)(κ2-O2CR)(PiPrPh2)2] by monitoring the H
tions the interconversion of the two isomers should be NMR spectra in [D8]toluene at low temperature, we failed
very fast.
to observe the characteristic signals for such hydridometal
The reactions of the carboxylato complexes 8 and 9 with species. Typical spectroscopic features of 24 and 25 are the
C2(CO2Me)2 proceed analogously to those with CO. Treat- two singlets for the stereochemically different protons of the
ment of the starting materials in benzene with an equimolar C(Ph)ϭCH2 ligand at about δ ϭ 5.4 to 6.0 in the 1H NMR
Eur. J. Inorg. Chem. 2002, 1377Ϫ1389
1379

H. Werner, F. Kukla, P. Steinert
FULL PAPER
Scheme 6. (L ϭ PiPrPh2)
spectrum and the doublet of triplets resonances for the al-
kynyl and vinyl carbon atoms in the region of δ ϭ 100 to
150 in the 13C NMR spectra. The 31P NMR spectra of 24
and 25 display a sharp doublet at about δ ϭ 30 with a 31P-
103Rh coupling constant of 105Ϫ106 Hz that is in agree-
ment with a trans-disposed Rh(PR3)2 unit.
Scheme 7. (L ϭ PiPrPh2)
rhodium compound [RhH2(κ2-O2CCH3)(PiPr3)2], con-
The reaction of the acetato compound 8 with methyl pro- taining two phosphane ligands that are more bulky than
piolate also affords an octahedral alkynyl(vinyl)rhodium- PiPrPh2, reacts with both HCϵCPh and HCϵCCO2Me to
(III) complex 26 but with a different stereochemistry at the give insertion products with a RhϪCHϭCHR stereochem-
1
CϭC double bond than 24. While the H NMR spectrum istry.[11,12] Moreover, the reaction of the six-coordinate hyd-
of 24 displays the signals for the vinylic protons at δ ϭ 5.87 ridoiridium(III) compound [IrHCl(CϵCCO2Me){κ1-P-
1
and 5.42, the H NMR spectrum of 26 exhibits the two iPr2P(CH2)2OMe}{κ2-P,O-iPr2P(CH2)2OMe}]
with
resonances at δ ϭ 9.18 and 6.33. Both are split into doub- HCϵCCO2Me also leads to an alkynyl(vinyl) complex with
1
1
1
lets of doublets of triplets due to H-1H, H-31P and H- an IrϪCHϭCHR linkage.[13]
103Rh coupling. There is no doubt, in particular owing to
In contrast to HCϵCPh and HCϵCCO2Me, the chloro-
the size of the H-1H coupling constant of 14.6 Hz, that in substituted alkyne HCϵCCH(Cl)Me reacts with one equiv.
1
26 the two protons at the CϭC double bond are trans to of 8 to give the allenylrhodium(III) compound 27 in 88%
each other. The same configuration has been found for the yield instead of an alkynyl complex (see Scheme 6). In this
bis(triisopropylphosphane) complex [Rh(κ2-O2CCH3)- process a migration of the chloride from the γ-carbon atom
(CϵCCO2Me){(Ε)-CHϭCHCO2Me}(PiPr3)2], which was of the alkyne to rhodium takes place, followed by the
prepared in a stepwise manner from [RhH2(κ2-O2CCH3)- formation of a σ bond between the metal and the remaining
(PiPr3)2] and three equiv. of HCϵCCO2Me under similar C3 unit. Although a variety of allenyl-transition metal com-
conditions.[11,12]
plexes have been prepared with allenyl halides as substrates,
A proposal for the mechanism of the reactions of 8 with there is ample evidence that propargylic chlorides or pro-
alkynes HCϵCR is outlined in Scheme 7. Although we pargylic alcohols can also be used to generate an MϪCHϭ
have no evidence for the formation of intermediate A, we CϭCRRЈ bond.[14,15] Characteristic spectroscopic data for
assume, in analogy to the reaction of [Rh(κ2-O2CCH3)- the allenyl ligand in 27 are the signals for the ϭCH and ϭ
(PiPr3)2] with phenylacetylene,[11] that in the first step such CCH3 protons at δ ϭ 4.96 and 1.53, respectively, which not
an alkynyl(hydrido)rhodium(III) species is generated. The only couple to each other but also exhibit a 1H-1H coupling
addition of a second molecule of HCϵCR should give in- with the proton at the α-carbon atom. The 13C NMR spec-
termediate B. With regard to the next step, it probably de- trum of 27 displays the resonances for the allenyl carbons
pends on steric as well as electronic effects whether pathway at δ ϭ 198.1, 87.4 and 83.0, of which only that of the metal-
(a) or (b) with the four-center transition states T1 and T2, bound C atom at δ ϭ 87.4 shows a 13C-31P and 13C-103Rh
respectively, is preferred. The above-mentioned dihydrido- coupling.
1380
Eur. J. Inorg. Chem. 2002, 1377Ϫ1389

Rhodium Complexes with [Rh(PiPr2Ph)2] and [Rh(PiPrPh2)2] as Molecular Units
FULL PAPER
The result of the X-ray crystal structure analysis of 27 under the conditions described in the Exp. Sect., the
is shown in Figure 1. The coordination geometry around branched enyne CH2ϭC(Ph)ϪCϵCPh almost exclusively.
1
rhodium is distorted octahedral with the two phosphanes According to the H NMR spectrum of the solution, taken
cis and the chloride and the allenyl ligand trans to each after 80% of phenylacetylene has been consumed, the iso-
other. Both the O1ϪRhϪO2 and P1ϪRhϪP2 bond angles mers (E)- and (Z)-PhCHϭCHϪCϵCPh are formed in less
deviate significantly from 90°, which is due on one hand to than 1% yield. In this context we note that Vinogradov et
the bite angle of the chelating acetate and on the other to al. previously reported that [RhCl(PMe3)3] catalyses the
steric hindrance between the substituents at the two phos- dimerization of terminal alkynes HCϵCR (R ϭ C3H7,
phorus atoms. The ClϪRhϪC1 axis is somewhat bent, the C4H9, C6H13) to afford a mixture of the enynes CH2ϭ
bond angle of 171.0(2)° being nearly identical to that of C(R)ϪCϵCR and (E)-RCHϭCHϪCϵCR with a selectiv-
the octahedral allenylosmium complex [OsCl2(η1-CHϭCϭ ity of 95Ϫ98%.[20] In this case the formation of alkynyl-
CPh2)(NO)(PiPr3)2] [170.5(1)°].[15] The RhϪC1 distance (vinyl)rhodium(III) compounds as intermediates has been
1
˚
[2.052(5) A] is slightly shorter than in trans-[Rh{η -(Z)- postulated.
[16]
˚
C(CHϭCH2)ϭCHPh}(CO)(PiPr3)2] [2.088(5) A]
and
˚
An enyne of the composition RCHϭC(R)ϪCϵCPh with
trans-[Rh{η1-C(CN)ϭCAn2}(CO)(PiPr3)2] [2.106(4) A; R ϭ CO2Me has been generated from the alkyne complexes
An ϭ p-C6H4OMe][17] but significantly longer than in the 21 and 22 in a stepwise manner. Treatment of a solution of
vinylrhodium
cation
[Rh{η1-(E)-CHϭCHCy}(κ2- 21 or 22 in dichloromethane at Ϫ20 °C with phenylacetyl-
acac)(PiPr3)2]ϩ [1.98(1) A].[18] The RhϪC1ϪC2 bond angle ene leads instantaneously to a change of color from pale-
is almost exactly 120° and thus in agreement with the sp2- yellow to red, followed quickly by a reverse change of color
hybridisation at the α-carbon atom of the C3 chain. In close from red to pale-yellow. After removal of the solvent and
analogy to uncoordinated allenes,[19] the two planes extraction of the residue with acetone, the pale-yellow air-
[Rh,C1,C2,H1] and [C2,C3,C4,H3] are nearly perpendi- sensitive solids 28 and 29, with an analytical composition
˚
cular to each other, with a dihedral angle of 88(2)°.
corresponding to 1:1 adducts of the starting materials and
Whereas attempts to reductively eliminate the enyne HCϵCPh, could be isolated (Scheme 8). Both the IR and
CH2ϭC(Ph)ϪCϵCPh by warming or irradiating solutions NMR spectra of 28 and 29 indicate that the two alkynes
of 24 or 25 failed, treatment of 25 with excess phenylacetyl- have been converted to an alkynyl and a vinyl ligand in the
ene in benzene at room temperature leads to the dimeriz- coordination sphere of the metal, the latter being generated
ation of the alkyne. The catalytic CϪC coupling process can from the coordinated disubstituted alkyne and the acidic
also be initiated by the carboxylatorhodium(I) compound 9 hydrogen atom of phenylacetylene. The supposed cis-posi-
(the starting material for the preparation of 25) and gives, tion of H and Rh at the CϭC double bond is supported by
˚
Figure 1. Molecular structure (ORTEP diagram) of 27; selected bond lengths [A] and angles [°]: RhϪP1 2.3050(17), RhϪP2 2.2910(19),
RhϪO1 2.178(4), RhϪO2 2.135(3), RhϪCl 2.4686(15), RhϪC1 2.051(5), C1ϪC2 1.263(7), C2ϪC3 1.336(8), C3ϪC4 1.475(9), O1ϪC5
1.255(6), O2ϪC5 1.264(6); P1ϪRhϪP2 100.61(6), P1ϪRhϪO1 103.41(11), P2ϪRhϪO1 155.78(10), P1ϪRhϪO2 163.94(12), P2ϪRhϪO2
95.11(12), P1ϪRhϪCl 96.30(5), P2ϪRhϪCl 98.12(5), P1ϪRhϪC1 87.73(15), P2ϪRhϪC1 89.08(15), ClϪRhϪC1 170.93(16),
ClϪRhϪO1 82.35(11), ClϪRhϪO2 84.62(10), O1ϪRhϪC1 88.81(18), O2ϪRhϪC1 89.27(18), O1ϪRhϪO2 60.74(14), RhϪC1ϪC2
120.8(4), C1ϪC2ϪC3 177.0(6), C2ϪC3ϪC4 122.8(6)
Eur. J. Inorg. Chem. 2002, 1377Ϫ1389
1381

H. Werner, F. Kukla, P. Steinert
FULL PAPER
doublet resonance for the equivalent phosphorus atoms is
observed in the 31P NMR spectrum of 30 at δ ϭ 18.9 and
thus shifted upfield by 12Ϫ15 ppm from 28 and 29. The
change of the coordination number at rhodium could be
responsible for this result. Although precise structural data
for 30 (which is a red air-sensitive oil) are missing, we as-
sume that the coordination geometry corresponds to a
square pyramid with the vinyl group in the apical position,
in analogy to [RhCl(CϵCPh){(Z)-CHϭCHPh}(PiPr3)2].[3]
The rearrangement of 30 to 31 by CϪC coupling occurs
smoothly and selectively in benzene at 60 °C and affords
the enyne complex 31 as an orange, relatively air-stable solid
in 75% isolated yield. The assumption that the enyne is co-
ordinated through the triple bond is mainly supported by
the IR spectrum, which shows the ν(CϵC) stretching mode
at 1835 cmϪ1, i.e. in a similar region as found for trans-
[RhCl(η2-PhCϵCPh)(PiPr3)2].[22] Passing a slow stream of
CO through a solution of 31 in CH2Cl2 at room temper-
ature results in a displacement of the enyne by CO and
leads to the carbonylrhodium(I) compound 32 and the free
enyne 33. The latter has been identified by comparison of
its spectroscopic data with those from the literature.[23] As
anticipated, 32 is also accessible from the dimer 3 and CO
in virtually quantitative yield.
Scheme 8. (L ϭ PiPrPh2)
In contrast to the carboxylato derivatives 8 and 9, the
the chemical shift of the resonance of the vinylic proton in sulfonate 12 reacts with terminal alkynes HCϵCR (R ϭ
1
the H NMR spectra, which is observed at δ ϭ 6.00 (for Ph, CMe2OH) to give the four-coordinate rhodium(I) vi-
28) and 6.04 (for 29) and thus at higher field than in the nylidene complexes 34 and 35 instead of alkynyl(vinyl)- or
case of a trans-position of H to rhodium.[3,16,21] The 13C allenylrhodium(III) complexes (Scheme 9). The reactions of
NMR spectroscopic data for the alkynyl and vinyl carbon 12 with HCϵCPh and HCϵCCMe2OH in a molar ratio of
atoms of 29 are quite similar to those of the structurally 1:1 were carried out in toluene at room temperature and
related compounds 24Ϫ26 and thus in agreement with the afford compounds 34 and 35 as violet air-sensitive solids
proposed structure. Regarding the course of the reaction of almost quantitatively. Although it is safe to assume that in
21 and 22 with phenylacetylene, we assume that a similar the initial step of the reaction an η2-alkynerhodium(I) spe-
mechanism is operative as suggested for the formation of cies is generated, which then rearranges, possibly via an al-
24 and 26. Treatment of the square-planar starting mat- kynyl(hydrido)rhodium(III) intermediate, to the isolated
erials 21 and 22 with HCϵCPh could lead via oxidative product,[24] we failed to detect such a species by NMR spec-
addition to a six-coordinate alkyne(alkynyl)hydridorhodium- troscopy. In analogy to the carboxylato complexes trans-
(III) species (see intermediate B in Scheme 7), which, after
insertion of the alkyne RCϵCR into the RhϪH bond and
concomitant closing of the chelate ring of the acetate, gives
the products.
The alkynyl(vinyl) complexes 28 and 29 are thermally
quite stable and even in the presence of CO do not react by
intramolecular CϪC coupling to yield trans-[Rh(κ1-
O2CR)(CO)(PiPrPh2)2] and the enyne. Such a reductive
elimination occurs if the related bis(triisopropylphosphane)
compound
[Rh(κ2-O2CCH3)(CϵCCO2Me){(Ε)-CHϭ
CHCO2Me}(PiPr3)2] is stirred in benzene under a CO at-
mosphere at 80 °C.[12] However, if a solution of 28 or 29 in
acetone is treated at Ϫ20 °C with an equimolar amount of
Me3SiCl, a fast reaction (illustrated by a quick change of
color from pale-yellow to red) takes place and the five-co-
ordinate chlororhodium(III) complex 30 is formed, along
with the corresponding silyl ester RCO2SiMe3 (R ϭ Me,
tBu; Scheme 8). While the signal for the vinylic proton in
the 1H NMR spectrum of 30 appears at practically the same
position (δ ϭ 6.04) as for the precursors 28 and 29, the Scheme 9. (L ϭ PiPr2Ph)
1382
Eur. J. Inorg. Chem. 2002, 1377Ϫ1389

Rhodium Complexes with [Rh(PiPr2Ph)2] and [Rh(PiPrPh2)2] as Molecular Units
[Rh(κ1-O2CR)(ϭCϭCHPh)(PiPr3)2] (R ϭ CH3, CF3),[11] generating
FULL PAPER
a
five-coordinate 18-electron intermediate,
the 13C NMR spectra of 34 and 35 display two low-field which, after migration of the alkynyl ligand to the α-carbon
resonances at δ ϭ 306.9 and 113.4 (for 34) and δ ϭ 308.2 atom of the vinylidene unit, transforms into the isolated
and 115.7 (for 35) assigned to the α- and β-carbon atoms product. The importance of steric factors probably explains
of the vinylidene units.
why the attack of the alkynyl moiety occurs only at that
The RhϪO bond in compounds 34 and 35 is quite labile side of the molecule that is opposite to the substituent RЈ.
and thus upon treatment of solutions of 34 or 35 in a 1:1 Compounds 39Ϫ41 are less air-sensitive than the precursors
mixture of toluene and triethylamine with an equimolar 36Ϫ38 both in the solid state and in solution. Typical spec-
amount of the corresponding alkyne HCϵCR at Ϫ50 °C a troscopic data of 39Ϫ41 are the intense ν(CO) and ν(CϵC)
substitution of the tosylate by the alkynyl anion takes place. stretching modes in the IR spectra at 1950Ϫ1955 cmϪ1 and
After warming to room temperature, removal of the solvent 2070Ϫ2160 cmϪ1, respectively, and the resonance for the
1
and extraction of the residue with ether the alkynyl(vinylid- vinylic ϭCH proton in the H NMR spectra at δ ϭ 8.07
ene) complexes 36 and 37 are isolated in 56Ϫ68% yield. (39), 7.18 (40) and 7.20 (41). The latter is split into a doub-
These compounds, which are turquoise or dark-green let of triplets due to 1H-103Rh and 1H-31P coupling. It
solids, can also be obtained directly from 12 and a twofold should also be mentioned that the methyl groups of the
excess of HCϵCR under similar conditions; in this case, PiPr2Ph ligands of 39Ϫ41 are diastereotopic and give rise
1
however, the yield is only 34Ϫ45%. Compounds 36 and 37 to four doublets of virtual triplets in the H NMR spectra.
are less stable in solution than the triisopropylphosphane We interpret this observation by assuming a hindered rota-
derivatives trans-[Rh(CϵCR)(ϭCϭCHR)(PiPr3)2],[3] which tion of the vinylic unit around the RhϪC σ-bond, probably
could be due to a reduced shielding of the metal center by caused by the steric requirements of the substituents at the
the smaller PiPr2Ph ligands. The alkynyl(vinylidene) com- phosphorus atoms and the CϭC bond.
pound 38, with different substituents at the β-C atom of the
In conclusion, the work described in this paper illustrates
carbon-bonded units, is accessible from 34 and the alkynol that a series of rhodium(I) and rhodium(III) complexes
HCϵCCMe2OH (see Scheme 10); it is significantly more with [Rh(PiPr2Ph)2] and [Rh(PiPrPh2)2] as molecular build-
air-sensitive than the counterparts 36 and 37. Attempts to ing blocks is accessible starting from the π-allylrhodium(I)
prepare the isomer of 38 with the composition trans- compounds 4 and 5. Protolytic cleavage of the allyl-metal
[Rh(CϵCPh)(ϭCϭCHCMe2OH)(PiPr2Ph)2] failed. Treat- bond by carboxylic acids or p-toluenesulfonic acid leads to
ment of a solution of 35 in toluene/NEt3 with one equiv. of the formation of carboxylato- and tosylatorhodium(I) de-
phenylacetylene affords a mixture of products which could rivatives, which easily undergo both addition and oxidative
not be separated by fractional crystallization or chromato- addition reactions. With terminal alkynes as substrates,
graphic techniques.
either alkynyl(vinyl)- or allenylrhodium(III) complexes were
obtained. Provided that CϵCPh is the alkynyl and
C(CO2Me)ϭCH(CO2Me) the vinyl ligand, the alkynyl(vi-
nyl) complexes react with Me3SiCl by intramolecular CϪC
coupling to give enynerhodium compounds from which the
free enyne is generated upon treatment with CO. The alkyn-
yl(vinylidene)rhodium(I) derivatives, which were prepared
in a stepwise manner from rhodium tosylates and terminal
alkynes, also react with CO by migratory insertion to afford
stereoselectively four-coordinate enynylrhodium(I) com-
plexes. Treatment of catalytic amounts of the pivalatorhod-
ium compounds 9 or 25 with excess phenylacetylene leads
to a dimerization of the alkyne and gives regioselectively
the branched enyne CH2ϭC(Ph)ϪCϵCPh.
Experimental Section
General: All operations were carried out under argon using Schlenk
techniques. The starting materials 1[25] and PHiPr2
were pre-
[26]
pared as described in the literature. NMR spectra were recorded at
room temperature on Bruker AC 200, Bruker AMX 400 and JEOL
FX 90 Q instruments, unless otherwise stated. Abbreviations used:
s, singlet; d, doublet; t, triplet; m, multiplet; vt, virtual triplet; br,
broadened signal; N ϭ JP,H ϩ JP,H or JP,C ϩ JP,C. The assign-
ment of protons for the π-allyl ligand in compounds 4Ϫ7 is as
follows: Hm ϭ proton at central carbon atom; Hs ϭ proton of
Scheme 10. (L ϭ PiPr2Ph)
The alkynyl(vinylidene) complexes 36Ϫ38 react quite
rapidly with CO in dichloromethane at Ϫ20 °C to give ex-
clusively the (Z) isomers of the enynylrhodium(I) com-
pounds 39؊41 in moderate to good yields (see Scheme 10).
2
3
2
4
We assume that initially CO adds to the metal center, thus terminal CH2 groups in syn position to Hm; Ha ϭ proton of ter-
Eur. J. Inorg. Chem. 2002, 1377Ϫ1389 1383

H. Werner, F. Kukla, P. Steinert
FULL PAPER
minal CH2 groups in anti position to Hm. Melting and decomposi-
tion points were measured by differential thermal analysis (DTA).
5.9 Hz, 2 H, Ha), 2.01, 1.93 (both m, 4 H, PCHCH3), 1.13 (dd,
3
3
3JP,H ϭ 13.5, JH,H ϭ 6.8 Hz, 6 H, PCHCH3), 1.11 (dd, JP,H
ϭ
3
3
16.2, JH,H ϭ 7.2 Hz, 6 H, PCHCH3), 1.04 (dd, JP,H ϭ 13.8,
Preparation of [RhCl(PiPr2Ph)2]2 (2): A suspension of 1 (250 mg,
0.35 mmol) in toluene (20 mL) was treated with PiPr2Ph (0.29 mL,
1.40 mmol) and stirred for 10 min at room temperature. The solv-
ent was evaporated in vacuo, the remaining violet solid was washed
three times with 5-mL portions of pentane and dried; yield 360 mg
3JH,H ϭ 6.9 Hz, 6 H, PCHCH3), 1.02 (dd, JP,H ϭ 16.5, JH,H
ϭ
3
3
7.1 Hz, 6 H, PCHCH3). 31P NMR (36.2 MHz, C6D6): δ ϭ 56.5 (d,
1JRh,P ϭ 187.6 Hz). C15H35P2Rh (380.3): calcd. C 47.38, H 9.28;
found C 47.23; H 9.35.
(98%); m.p. 105 °C (dec.). 1H NMR (200 MHz, C6D6): δ ϭ Preparation of [Rh(η3-C3H5)(PtBu2Me)2] (7): This compound was
7.37Ϫ6.79 (m, 20 H, C6H5), 2.28 (m, 8 H, PCHCH3), 1.70, 1.11 prepared as described for 4, with 1 (287 mg, 0.40 mmol), PtBu2Me
(both m, 48 H, PCHCH3). 31P NMR (81.0 MHz, C6D6): δ ϭ 58.9
(0.32 mL, 1.60 mmol) and a 0.5  solution of C3H5MgBr in ether
1
(d, JRh,P ϭ 197.7 Hz). C48H76Cl2P4Rh2 (1053.8): calcd. C 54.71, (1.6 mL, 0.80 mmol) as starting materials. Yellow air-sensitive
1
H 7.27; found C 54.49, H 7.79.
solid; yield 320 mg (86%); m.p. 86 °C (dec.). H NMR (400 MHz,
C6D6): δ ϭ 4.63 (dtt, 2JRh,H ϭ 2.1, 3JH,Ha ϭ 11.7, 3JH,Hs ϭ 6.7 Hz,
Preparation of [RhCl(PiPrPh2)2]2 (3): This compound was prepared
as described for 2, with 1 (250 mg, 0.35 mmol) and PiPrPh2
(0.32 mL, 1.40 mmol) as starting materials. Violet solid; yield
394 mg (95%); m.p. 98 °C (dec.). 1H NMR (200 MHz, CD2Cl2):
δ ϭ 7.36Ϫ7.06 (m, 40 H, C6H5), 2.22 (m, 4 H, PCHCH3), 0.92
3
3
1 H, Hm), 3.74 (d, JH,Hm ϭ 6.7 Hz, 2 H, Hs), 1.92 (dd, JH,Hm
ϭ
3
3
11.7, JP,H ϭ 6.1 Hz, 2 H, Ha), 1.22 (d, JP,H ϭ 12.0 Hz, 18 H,
2
3
PCCH3), 1.14 (d, JP,H ϭ 4.3 Hz, 6 H, PCH3), 1.11 (d, JP,H
ϭ
11.6 Hz, 18 H, PCCH3). 31P NMR (36.2 MHz, C6D6): δ ϭ 53.3 (d,
1JRh,P ϭ 196.4 Hz). C21H47P2Rh (464.5): calcd. C 54.31, H 10.20;
found C 54.82, H 10.32.
3
3
(dd, JP,H ϭ 14.4, JH,H ϭ 6.9 Hz, 12 H, PCHCH3). 31P NMR
1
(81.0 MHz, CD2Cl2):
δ
ϭ
55.2 (d, JRh,P
ϭ
197.6 Hz).
C60H68Cl2P4Rh2 (1189.8): calcd. C 60.57, H 5.76; found C 60.08,
H 5.81.
Preparation of [Rh(κ2-O2CCH3)(PiPrPh2)2] (8): A solution of 5
(180 mg, 0.30 mmol) in benzene (2 mL) was treated with acetic acid
(17 µL, 0.30 mmol) and stirred for 1 h at room temperature. A
change of color from yellow to dark red occurred. The solvent was
evaporated in vacuo, the residue was extracted with acetone
(20 mL) and the extract was concentrated to ca. 3 mL in vacuo. A
dark-red microcrystalline solid was obtained, which was filtered,
washed twice with 2-mL portions of acetone (0 °C) and dried; yield
165 mg (89%); m.p. 108 °C. IR (C6H6): ν(OCOas) ϭ 1510,
Preparation of [Rh(η3-C3H5)(PiPr2Ph)2] (4): A suspension of 1
(574 mg, 0.80 mmol) in toluene (5 mL) was treated with PiPr2Ph
(0.66 mL, 3.20 mmol) and stirred for 10 min at room temperature.
After cooling the solution to 0 °C, a 0.5  solution of C3H5MgBr
in ether (3.2 mL, 1.60 mmol) was added dropwise. A change of
color from brown-violet to yellow occurred. The solvent was evap-
orated in vacuo, the residue was extracted with pentane (30 mL)
and the extract was dried in vacuo. A yellow air-sensitive solid was
obtained which was washed three times with 2-mL portions of acet-
one (0 °C) and dried; yield 700 mg (82%); m.p. 77 °C (dec.). 1H
NMR (400 MHz, C6D6): δ ϭ 7.41Ϫ6.83 (m, 10 H, C6H5), 5.02
ν(OCOsym) ϭ 1445 cmϪ1 1H NMR (400 MHz, C6D6): δ ϭ
.
7.83Ϫ6.69 (m, 20 H, C6H5), 2.32 (m, 2 H, PCHCH3), 1.95 (s, 3 H,
O2CCH3), 1.10 (m, 12 H, PCHCH3). 31P NMR (162.0 MHz,
1
C6D6): δ ϭ 61.9 (d, JRh,P ϭ 199.7 Hz). C32H37O2P2Rh (618.5):
calcd. C 62.14, H 6.03; found C 61.75, H 5.98.
2
3
3
(dtt, JRh,H ϭ 2.1, JH,Ha ϭ 12.8, JH,Hs ϭ 6.8 Hz, 1 H, Hm), 3.36
(d, 3JH,Hm ϭ 6.8 Hz, 2 H, Hs), 2.49, 2.37 (both m, 4 H, PCHCH3),
Preparation of [Rh{κ2-O2CC(CH3)3}(PiPrPh2)2] (9): This com-
2.35 (dd, 3JH,Hm ϭ 12.8, 3JP,H ϭ 7.0 Hz, 2 H, Ha), 1.10 (dd, 3JP,H ϭ pound was prepared as described for 8, with 5 (150 mg, 0.25 mmol)
3
3
15.0, JH,H ϭ 7.0 Hz, 6 H, PCHCH3), 1.08 (dd, JP,H ϭ 14.4, and (CH3)3CCO2H (26 µL, 0.25 mmol) as starting materials; reac-
3JH,H ϭ 7.0 Hz, 6 H, PCHCH3), 0.99 (dd, JP,H ϭ 12.4, JH,H
ϭ
tion time: 6 h. Dark-red solid; yield 129 mg (78%); m.p. 93 °C
3
3
6.6 Hz, 6 H, PCHCH3), 0.90 (dd, JP,H ϭ 12.0, JH,H ϭ 6.8 Hz, 6 (dec.). IR (KBr): ν(OCOas) ϭ 1485, ν(OCOsym) ϭ 1430 cmϪ1. H
3
3
1
H, PCHCH3). 31P NMR (81.0 MHz, C6D6): δ ϭ 53.2 (d, JRh,P
ϭ
NMR (400 MHz, C6D6): δ ϭ 7.52Ϫ6.81 (m, 20 H, C6H5), 2.37 (m,
1
196.2 Hz). C27H43P2Rh (532.5): calcd. C 60.90, H 8.14; found C 2 H, PCHCH3), 1.34 [s, 9 H, C(CH3)3], 1.02 (m, 12 H, PCHCH3).
1
60.23; H. 8.01.
31P NMR (162.0 MHz, C6D6): δ ϭ 62.2 (d, JRh,P ϭ 226.0 Hz).
C35H43O2P2Rh (660.9): calcd. C 63.64, H 6.56; found C 64.03, H
6.81.
Preparation of [Rh(η3-C3H5)(PiPrPh2)2] (5): This compound was
prepared as described for 4, with 1 (287 mg, 0.40 mmol), PiPrPh2
(0.37 mL, 1.60 mmol) and a 0.5  solution of C3H5MgBr in ether
Preparation of [Rh{κ2-O2CC(CH3)3}(PiPr2Ph)2] (10): This com-
pound was prepared as described for 8, with 4 (149 mg, 0.28 mmol)
solid; yield 384 mg (80%); m.p. 76 °C (dec.). H NMR (400 MHz, and (CH3)3CCO2H (29 µL, 0.28 mmol) as starting materials; reac-
(1.6 mL, 0.80 mmol) as starting materials. Yellow air-sensitive
1
2
C6D6): δ ϭ 7.45Ϫ7.02 (m, 20 H, C6H5), 5.08 (dtt, JRh,H ϭ 2.1, tion time: 6 h. Dark-red solid; yield 123 mg (74%); m.p. 97 °C
3JH,Ha ϭ 12.2, 3JH,Hs ϭ 6.8 Hz, 1 H, Hm), 3.31 (d, 3JH,Hm ϭ 6.8 Hz, (dec.). IR (C6H6): ν(OCOas) ϭ 1480, ν(OCOsym) ϭ 1425 cmϪ1. H
1
3
3
2 H, Hs), 2.37 (dd, JH,Hm ϭ 12.2, JP,H ϭ 4.7 Hz, 2 H, Ha), 2.15 NMR (200 MHz, C6D6): δ ϭ 7.58Ϫ6.91 (m, 10 H, C6H5), 2.25 (m,
3
3
(m, 2 H, PCHCH3), 0.99 (dd, JP,H ϭ 14.7, JH,H ϭ 6.9 Hz, 6 H, 4 H, PCHCH3), 1.53 (m, 12 H, PCHCH3), 1.42 [s, 9 H, C(CH3)3],
PCHCH3), 0.91 (dd, 3JP,H ϭ 14.4, 3JH,H ϭ 7.0 Hz, 6 H, PCHCH3).
1.15 (m, 12 H, PCHCH3). 31P NMR (81.0 MHz, C6D6): δ ϭ 66.6
1
1
31P NMR (162.0 MHz, C6D6): δ ϭ 49.9 (d, JRh,P ϭ 197.3 Hz). (d, JRh,P ϭ 202.1 Hz). C29H47O2P2Rh (592.6): calcd. C 58.78, H
C33H39P2Rh (600.5): calcd. C 66.00, H 6.55; found C 65.90, H 6.56.
7.99; found C 58.51, H 8.02.
Preparation of [Rh(η3-C3H5)(PHiPr2)2] (6): This compound was
Preparation of [Rh{κ2-O2S(O)-p-Tol}(PiPrPh2)2] (11): A solution of
prepared as described for 4, with 1 (287 mg, 0.40 mmol), PHiPr2 5 (180 mg, 0.30 mmol) in toluene (2 mL) was treated with 4-
(0.24 mL, 1.60 mmol) and a 0.5  solution of C3H5MgBr in ether MeC6H4SO3H (57 mg, 0.30 mmol) and stirred for 1 h at room tem-
(1.6 mL, 0.80 mmol) as starting materials. Yellow air-sensitive
perature. A change of color from yellow to red occurred. The solv-
1
solid; yield 253 mg (83%); m.p. 65 °C (dec.). H NMR (400 MHz, ent was evaporated in vacuo, the residue was extracted with acetone
C6D6): δ ϭ 4.82 (dtt, 2JRh,H ϭ 1.9, 3JH,Ha ϭ 12.7, 3JH,Hs ϭ 7.2 Hz, (20 mL) and the extract was concentrated to ca. 2 mL in vacuo.
1
3
1 H, Hm), 4.06 (dt, JP,H ϭ 256.5, JH,H ϭ 4.8 Hz, 2 H, PH), 3.68
Red crystals precipitated which were filtered, washed twice with 2-
mL portions of acetone (0 °C) and dried; yield 185 mg (89%); m.p.
3
3
3
(d, JH,Hm ϭ 7.2 Hz, 2 H, Hs), 2.22 (dd, JH,Hm ϭ 12.7, JP,H
ϭ
1384
Eur. J. Inorg. Chem. 2002, 1377Ϫ1389

Rhodium Complexes with [Rh(PiPr2Ph)2] and [Rh(PiPrPh2)2] as Molecular Units
51 °C. 1H NMR (200 MHz, C6D6): δ ϭ 7.58Ϫ6.91 (m, 24 H, C6H4 Preparation of [RhH2{κ2-O2CC(CH3)3}(PiPrPh2)2] (17): This com-
FULL PAPER
and C6H5), 2.31 (m, 2 H, PCHCH3), 1.95 (s, 3 H, C6H4CH3), 0.96 pound was prepared as described for 16, with 9 (66 mg, 0.10 mmol)
(m, 12 H, PCHCH3). 31P NMR (81.0 MHz, C6D6): δ ϭ 63.3 (d, and H2 as starting materials. White solid; yield 58 mg (88%); m.p.
1JRh,P ϭ 212.2 Hz). C37H41O3P2RhS (730.7): calcd. C 60.82, H
5.66, S 4.39; found C 60.82, H 5.89, S 4.33.
76 °C (dec.). IR (KBr): ν(RhH) ϭ 2115, ν(OCOas) ϭ 1525,
ν(OCOsym) ϭ 1430 cmϪ1 1H NMR (200 MHz, C6D6): δ ϭ
.
6.99Ϫ6.71 (m, 20 H, C6H5), 2.33 (m, 2 H, PCHCH3), 1.08 (dvt,
Preparation of [Rh{κ2-O2S(O)-p-Tol}(PiPr2Ph)2] (12): This com-
N ϭ 16.7, 3JH,H ϭ 8.0 Hz, 12 H, PCHCH3), 0.79 [s, 9 H, C(CH3)3],
1
2
Ϫ21.13 (dt, JRh,H ϭ 21.8, JP,H ϭ 17.4 Hz, 2 H, RhH). 31P NMR
(81.0 MHz, C6D6): δ ϭ 49.8 (d, 1JRh,P ϭ 119.2 Hz). C35H45O2P2Rh
(662.6): calcd. C 63.45, H 6.85; found C 63.90, H 7.12.
pound was prepared as described for 11, with
4 (128 mg,
0.24 mmol) and 4-MeC6H4SO3H (46 mg, 0.24 mmol) as starting
materials. Red air-sensitive crystals; yield 138 mg (87%); m.p. 85 °C
(dec.). 1H NMR (200 MHz, C6D6): δ ϭ 8.46Ϫ6.79 (m, 14 H, C6H4
and C6H5), 2.10 (m, 4 H, PCHCH3), 1.97 (s, 3 H, C6H4CH3), 1.35,
1.03 (both m, 12 H each, PCHCH3). 31P NMR (81.0 MHz, C6D6):
Preparation of [RhH2{κ2-O2CC(CH3)3}(PiPr2Ph)2] (18): This com-
pound was prepared as described for 16, with 10 (65 mg,
0.11 mmol) and H2 as starting materials. Colorless oil; yield 65 mg
(99%). IR (KBr): ν(RhH) ϭ 2120, ν(OCOas) ϭ 1520, ν(OCOsym) ϭ
1
δ ϭ 63.3 (d, JRh,P ϭ 212.2 Hz). C31H45O3P2RhS (662.6): calcd. C
56.19, H 6.84, S 4.84; found C 55.82, H 6.53, S 4.71.
1
1420 cmϪ1. H NMR (200 MHz, C6D6): δ ϭ 7.88Ϫ6.92 (m, 10 H,
Preparation of trans-[Rh(κ1-O2CCH3)(CO)(PiPrPh2)2] (13): A slow
stream of CO was passed through a solution of 8 (62 mg,
0.10 mmol) in CH2Cl2 (10 mL) at room temperature for 10 s, lead-
ing to a rapid change of color from dark-red to light yellow. After
removal of the solvent in vacuo, a light yellow solid was obtained,
which was washed twice with 2-mL portions of acetone (0 °C) and
dried; yield (98%); m.p. 135 °C. IR (KBr): ν(CO) ϭ 1960,
3
C6H5), 2.26 (m, 4 H, PCHCH3), 1.28 (dvt, N ϭ 14.5, JH,H
ϭ
7.3 Hz, 12 H, PCHCH3), 1.14 [s, 9 H, C(CH3)3], 1.02 (dvt, N ϭ
3
1
13.1, JH,H ϭ 7.3 Hz, 12 H, PCHCH3), Ϫ22.73 (dt, JRh,H ϭ 23.3,
2JP,H ϭ 16.0 Hz, 2 H, RhH). 31P NMR (81.0 MHz, C6D6): δ ϭ
55.3 (d, 1JRh,P ϭ 119.1 Hz). C29H49O2P2Rh (594.6): calcd. C 58.58,
H 8.31; found C 58.45, H 8.28.
Preparation of [RhH2{κ2-O2S(O)-p-Tol}(PiPrPh2)2] (19): This com-
pound was prepared as described for 16, with 11 (73 mg,
0.10 mmol) and H2 as starting materials. White solid which has to
be stored under dihydrogen; yield 62 mg (85%); m.p. 86 °C (dec.).
IR (KBr): ν(RhH) ϭ 2100 cmϪ1. 1H NMR (200 MHz, C6D6): δ ϭ
7.87Ϫ6.49 (m, 24 H, C6H5 and C6H4), 3.08 (m, 2 H, PCHCH3),
1
ν(OCOas) ϭ 1595, ν(OCOsym) ϭ 1370 cmϪ1. H NMR (400 MHz,
C6D6): δ ϭ 7.83Ϫ7.41 (m, 20 H, C6H5), 2.93 (m, 2 H, PCHCH3),
1.36 (s, 3 H, O2CCH3), 1.21 (dvt, N ϭ 15.8, 3JH,H ϭ 7.4 Hz, 12 H,
1
PCHCH3). 31P NMR (162.0 MHz, C6D6): δ ϭ 40.7 (d, JRh,P
ϭ
147.4 Hz). C33H37O3P2Rh (646.5): calcd. C 61.31, H 5.77; found C
61.00, H 5.30.
3
1.80 (s, 3 H, C6H4CH3), 1.12 (dvt, N ϭ 15.8, JH,H ϭ 7.9 Hz, 12
1
2
Preparation of trans-[Rh{κ1-O2CC(CH3)3}(CO)(PiPr2Ph)2] (14):
This compound was prepared as described for 13, with 10 (59 mg,
0.10 mmol) and CO as starting materials. Yellow solid; yield 59 mg
(95%); m.p. 93 °C (dec.). IR (KBr): ν(CO) ϭ 1955 cmϪ1. 1H NMR
(200 MHz, C6D6): δ ϭ 7.77Ϫ7.07 (m, 10 H, C6H5), 2.42 (m, 4 H,
H, PCHCH3), Ϫ21.51 (dt, JRh,H ϭ 27.6, JP,H ϭ 15.8 Hz, 2 H,
RhH). 31P NMR (81.0 MHz, C6D6): δ ϭ 50.2 (d, JRh,P
ϭ
1
117.8 Hz). C37H43O3P2RhS (732.7): calcd. C 60.66, H 5.92; found
C 61.21, H 6.21.
Preparation of [RhH2{κ2-O2S(O)-p-Tol}(PiPr2Ph)2] (20): This com-
pound was prepared as described for 16, with 12 (60 mg,
0.09 mmol) and H2 as starting materials. Colorless oil which has to
be stored under dihydrogen; yield 59 mg (98%). IR (KBr):
ν(RhH) ϭ 2130 cmϪ1. 1H NMR (200 MHz, C6D6): δ ϭ 7.81Ϫ6.65
(m, 14 H, C6H5 and C6H4), 2.52 (m, 4 H, PCHCH3), 1.87 (s, 3 H,
C6H4CH3), 1.28 (dvt, N ϭ 14.5, 3JH,H ϭ 7.3 Hz, 12 H, PCHCH3),
0.98 (dvt, N ϭ 14.5, 3JH,H ϭ 7.3 Hz, 12 H, PCHCH3), Ϫ24.04 (dt,
1JRh,H ϭ 27.6, 2JP,H ϭ 16.0 Hz, 2 H, RhH). 31P NMR (81.0 MHz,
3
PCHCH3), 1.37 (dvt, N ϭ 16.1, JH,H ϭ 7.3 Hz, 12 H, PCHCH3),
3
1.14 [s, 9 H, C(CH3)3], 1.03 (dvt, N ϭ 14.2, JH,H ϭ 6.9 Hz, 12 H,
1
PCHCH3). 31P NMR (81.0 MHz, C6D6): δ ϭ 46.4 (d, JRh,P
ϭ
133.7 Hz). C30H47O3P2Rh (620.6): calcd. C 58.07, H 7.63; found C
57.60, H 7.46.
Preparation of [Rh{κ1-O2S(O)-p-Tol}(CO)(PiPr2Ph)2] (15): This
compound was prepared as described for 13, with 12 (66 mg,
0.10 mmol) and CO as starting materials. Yellow solid; yield 64 mg
(93%); m.p. 153 °C (dec.). IR (KBr): ν(CO) ϭ 1950 cmϪ1. 1H NMR
(200 MHz, C6D6): δ ϭ 7.96Ϫ6.82 (m, 14 H, C6H5 and C6H4), 2.81
1
C6D6): δ ϭ 51.8 (d, JRh,P ϭ 117.7 Hz). C31H47O3P2RhS (664.6):
calcd. C 56.02, H 7.13, S 4.82; found C 55.31, H 7.01, S 4.75.
Preparation of trans-[Rh(κ1-O2CCH3){η2-C2(CO2Me)2}(PiPrPh2)2]
(21): A solution of 8 (74 mg, 0.12 mmol) in benzene (5 mL) at room
temperature was treated dropwise with C2(CO2Me)2 (14 µL,
0.12 mmol) with continuous stirring. A quick change of color from
dark-red to yellow occurred. The solvent was evaporated in vacuo
and the oily residue dissolved in hexane (2 mL). After the solution
was stored at Ϫ78 °C for 12 h, a pale-yellow solid precipitated,
which was separated from the mother liquor, washed twice with 2-
mL portions of pentane and dried in vacuo; yield: 78 mg (85%);
m.p. 94 °C (dec.). IR (KBr): ν(CϵC) ϭ 1810, ν(CϭO) ϭ 1680,
ν(OCO) ϭ 1610 cmϪ1. 1H NMR (200 MHz, C6D6): δ ϭ 7.81Ϫ7.00
(m, 20 H, C6H5), 3.24 (s, 6 H, CO2CH3), 2.68 (m, 2 H, PCHCH3),
(m, 4 H, PCHCH3), 1.95 (s, 3 H, C6H4CH3) 1.44 (dvt, N ϭ 16.9,
3
3JH,H ϭ 7.5 Hz, 12 H, PCHCH3), 0.96 (dvt, N ϭ 14.5, JH,H
ϭ
7.0 Hz, 12 H, PCHCH3). 31P NMR (81.0 MHz, C6D6): δ ϭ 47.7
1
(d, JRh,P ϭ 125.0 Hz). C32H45O4P2RhS (690.6): calcd. C 55.65; H
6.57; found C 56.07, H 6.81.
Preparation of [RhH2(κ2-O2CCH3)(PiPrPh2)2] (16): A slow stream
of H2 was passed through a solution of 8 (62 mg, 0.10 mmol) in
CH2Cl2 (5 mL) at room temperature for 5 min. After removal of
the solvent in vacuo, a white solid was obtained which was washed
twice with 1-mL portions of acetone (0 °C) and dried; yield 56 mg
(90%); m.p. 84 °C (dec.). IR (KBr): ν(RhH) ϭ 2100, ν(OCOas) ϭ
1540, ν(OCOsym) ϭ1430 cmϪ1 1H NMR (400 MHz, C6D6): δ ϭ
.
3
1.55 (dvt, N ϭ 14.0, JH,H ϭ 7.0 Hz, 12 H, PCHCH3), 1.34 (s, 3
7.99Ϫ6.91 (m, 20 H, C6H5), 2.53 (m, 2 H, PCHCH3), 1.52 (s, 3 H,
1
H, O2CCH3). 31P NMR (81.0 MHz, C6D6): δ ϭ 34.6 (d, JRh,P
ϭ
3
O2CCH3), 1.21 (dvt, N ϭ 15.9, JH,H ϭ 8.0 Hz, 12 H, PCHCH3),
118.3 Hz). C38H43O6P2Rh (760.6): calcd. C 60.01, H 5.70; found C
60.48, H 5.95.
1
2
Ϫ22.01 (dt, JRh,H ϭ 22.4, JP,H ϭ 18.0 Hz, 2 H, RhH). 31P NMR
1
(162.0 MHz, C6D6):
δ
ϭ
49.7 (d, JRh,P
ϭ
119.4 Hz).
C32H39O2P2Rh (620.5): calcd. C 61.94, H 6.33; found C 62.20, H
6.48.
Preparation
of
trans-[Rh{κ1-O2CC(CH3)3}{η2-C2(CO2Me)2}
(PiPrPh2)2] (22): This compound was prepared as described for 21,
Eur. J. Inorg. Chem. 2002, 1377Ϫ1389
1385

H. Werner, F. Kukla, P. Steinert
with 9 (79 mg, 0.12 mmol) and C2(CO2Me)2 (14 µL, 0.12 mmol). 104.6 Hz). MS (70 eV, e-spray): m/z ϭ 864 [Mϩ]. C51H55O2P2Rh
FULL PAPER
Pale-yellow solid; yield 79 mg (86%); m.p. 84 °C (dec.). IR (KBr):
(864.9): calcd. C 70.83, H 6.41; found C 70.79, H 6.40.
ν(CϵC) ϭ 1785, ν(CϭO) ϭ 1685, ν(OCOas) ϭ 1610 cmϪ1 1H
.
Catalytic Dimerization of Phenylacetylene: A solution of either 9
(165 mg, 0.25 mmol) or 25 (260 mg, 0.25 mmol) in benzene (25 mL)
was treated with phenylacetylene (2.7 mL, 25 mmol) and hexane
(1 mL, as a reference for GC) and stirred whilst irradiating with an
Osram 500 W lamp (λ ϭ 300 nm) at room temperature. After 6 h,
the GC plot (measured with a Shimadzu GC-8A gas chromato-
graph and a FFAP column) revealed that 80% of phenylacetylene
had been consumed. The volatiles were removed in vacuo and the
remaining red-brown oil investigated by 1H NMR spectroscopy.
The 1H NMR spectrum showed that the major product was the
enyne PhCϵCC(Ph)ϭCH2, whereas the isomeric butenynes (E)-
and (Z)-PhCϵCCHϭCHPh were present in less than 1%. The red-
brown oil was dissolved in benzene (2 mL) and the solution chro-
matographed on Al2O3 (neutral, activity grade I, height of column
15 cm). A yellow fraction was eluted with hexane, which was then
dried in vacuo. The yellow oil (which slowly polymerizes at temper-
atures above Ϫ40 °C) was identified as PhCϵCC(Ph)ϭCH2 by
comparison of its NMR spectroscopic data with those of the liter-
ature.[27]
NMR (200 MHz, C6D6): δ ϭ 7.85Ϫ6.98 (m, 20 H, C6H5), 3.32 (s,
6 H, CO2CH3), 2.64 (m, 2 H, PCHCH3), 1.03 (dvt, N ϭ 12.8,
3JH,H ϭ 5.7 Hz, 12 H, PCHCH3), 0.75 [s, 9 H, C(CH3)3]. 31P NMR
(81.0 MHz, C6D6): δ ϭ 35.9 (d, 1JRh,P ϭ 120.0 Hz). C41H49O6P2Rh
(802.7): calcd. C 61.35, H 6.15; found C 60.97, H 5.98.
Preparation of trans-[Rh{κ1-O2CC(CH3)3}(η2-MeCϵCCO2Me)-
(PiPrPh2)2] (23): A solution of 9 (92 mg, 0.14 mmol) in toluene
(2 mL) was treated dropwise at Ϫ20 °C with MeC2CO2Me (14 µL,
0.14 mmol). After stirring the solution at Ϫ20 °C for 2 h and then
warming to room temperature, the solvent was evaporated in va-
cuo. The oily residue was dissolved in hexane (2 mL) and the solu-
tion worked up as described for 21. Pale-yellow solid; yield 67 mg
(63%); m.p. 64 °C (dec.). IR (KBr): ν(CϵC) ϭ 1900, ν(CϭO) ϭ
1705, ν(OCOas) ϭ 1670 cmϪ1 1H NMR (200 MHz, [D8]toluene,
.
243 K): δ ϭ 7.92Ϫ6.84 (m, 20 H, C6H5), 3.33 (s, 3 H, CO2CH3),
2.38 (m, 2 H, PCHCH3), 1.32 [s, 9 H, C(CH3)3], 1.30 (dvt, N ϭ
3
17.3, JH,H ϭ 8.6 Hz, 12 H, PCHCH3), 1.10 (s, 3 H, ϵCCH3).
1
31P NMR (81.0 MHz, [D8]toluene, 243 K): δ ϭ 36.4 (d, JRh,P
ϭ
123.5 Hz). C40H49O4P2Rh (758.7):calcd. C 63.33, H 6.51; found C
63.45, H 6.55.
Preparation
of
[Rh(κ2-O2CCH3)(CϵCCO2Me){(E)-CH؍
CHCO2Me}(PiPrPh2)2] (26): This compound was prepared as de-
scribed for 24, with 8 (74 mg, 0.12 mmol) and methyl propiolate
(22 µL, 0.24 mmol) as starting materials. Pale-yellow solid; yield
83 mg (88%); m.p. 132 °C (dec.). IR (KBr): ν(CϵC) ϭ 2090, ν(Cϭ
Preparation of [Rh(κ2-O2CCH3)(CϵCPh){C(Ph)؍CH2}(PiPrPh2)2]
(24): A solution of 8 (93 mg, 0.15 mmol) in toluene (5 mL) at Ϫ50
°C was treated dropwise with phenylacetylene (32 µL, 0.30 mmol).
After stirring the solution for 5 min at Ϫ50 °C and then warming
to room temperature, the solvent was evaporated in vacuo. The oily
residue was dissolved in hexane (20 mL) and the solution stirred at
0 °C for 2 h. A pale-yellow solid slowly precipitated, which was
filtered, washed twice with 2-mL portions of hexane and dried in
vacuo; yield 106 mg (86%); m.p. 81 °C (dec.). IR (KBr): ν(CϵC) ϭ
1
O) ϭ 1675, ν(OCOas) ϭ 1570 cmϪ1. H NMR (200 MHz, C6D6):
3
3
2
δ ϭ 9.18 (ddt, JH,H ϭ 14.6, JP,H ϭ 2.9, JRh,H ϭ 0.9 Hz, 1 H,
3
RhCH), 7.77Ϫ6.95 (m, 20 H, C6H5), 6.33 (ddt, JH,H ϭ 14.6,
4JP,H ϭ 1.5, 3JRh,H ϭ 1.5 Hz, 1 H, ϭCHCO2CH3), 3.38, 3.36 (both
s, 6 H, CO2CH3), 3.06 (m, 2 H, PCHCH3), 1.30 (dvt, N ϭ 15.7,
3
3JH,H ϭ 7.3 Hz, 6 H, PCHCH3), 1.06 (dvt, N ϭ 15.0, JH,H
ϭ
7.3 Hz, 6 H, PCHCH3), 1.05 (s, 3 H, O2CCH3). 13C NMR
2060, ν(CϭC) ϭ 1580, ν(OCOas) ϭ 1520 cmϪ1 1H NMR
.
(400 MHz, C6D6): δ ϭ 8.04Ϫ6.46 (m, 30 H, C6H5), 5.87, 5.42 (both
s, 1 H each, ϭCH2), 3.35 (m, 2 H, PCHCH3), 1.45 (dvt, N ϭ 14.8,
(100.6 MHz, C6D6): δ ϭ 184.7 (s, RhO2CCH3), 168.0 (dt, 1JRh,C ϭ
2
3
4
29.3, JP,C ϭ 9.8 Hz, RhCH), 162.7 (dt, JRh,C ϭ 2.7, JP,C
ϭ
3
4
1.3 Hz, CCO2CH3), 153.7 (dt, JRh,C ϭ 1.6, JP,C ϭ 1.3 Hz,
CO2CH3), 135.2, 134.7 (both vt, N ϭ 9.8 Hz, ortho-C of C6H5),
130.3, 130.2 (both s, para-C of C6H5), 129.2, 129.2 (both vt, N ϭ
41.8 Hz, ipso-C of C6H5), 128.0, 127.9 (both vt, N ϭ 9.4 Hz, meta-
C of C6H5), 127.5 (dt, 2JRh,C ϭ 9.3, 3JP,C ϭ 4.5 Hz, ϭCHCO2CH3),
3
3JH,H ϭ 7.4 Hz, 6 H, PCHCH3), 1.22 (dvt, N ϭ 14.6, JH,H
ϭ
7.2 Hz, 6 H, PCHCH3), 1.20 (s, 3 H, O2CCH3). 13C NMR
1
(100.6 MHz, C6D6): δ ϭ 182.2 (s, O2C), 148.4 [dt, JRh,C ϭ 30.4,
2JP,C ϭ 8.9 Hz, RhC(ϭCH2)Ph], 134.2Ϫ124.0 (m, C6H5), 128.6 [dt,
2JRh,C ϭ 1.2, JP,C ϭ 0.8 Hz, ϭCH2], 108.7 (dt, JRh,C ϭ 10.2,
3
2
1
2
109.1 (dt, JRh,C ϭ 50.5, JP,C ϭ 17.1 Hz, RhCϵC), 103.6 (dt,
3JP,C ϭ 2.3 Hz, ϵCPh], 98.5 [dt, JRh,C ϭ 50.7, JP,C ϭ 18.5 Hz,
RhCϵCPh], 25.6 (vt, N ϭ 25.3 Hz, PCHCH3), 22.9 (s, O2CCH3),
18.2, 17.4 (both s, PCHCH3). 31P NMR (81.0 MHz, C6D6): δ ϭ
31.0 (d, 1JRh,P ϭ 106.1 Hz). C48H49O2P2Rh (822.8): calcd. C 70.07,
H 6.00; found C 69.72, H 6.14.
1
2
2JRh,C ϭ 11.0, JP,C ϭ 2.4 Hz, RhCϵC), 50.4, 50.1 (both s,
3
CO2CH3), 26.9 (vt, N ϭ 26.5 Hz, PCHCH3), 23.9 (s, O2CCH3),
18.9, 18.8 (both s, PCHCH3). 31P NMR (81.0 MHz, C6D6): δ ϭ
1
33.6 (d, JRh,P ϭ 98.8 Hz). C40H45O6P2Rh (786.7): calcd. C 61.07,
H 5.77; found C 60.71, H 5.43.
Preparation
of
[Rh{κ2-O2CC(CH3)3}(CϵCPh){C(Ph)؍CH2} Preparation of [RhCl(κ2-O2CCH3)(CH؍C؍CHMe)(PiPrPh2)2]
(PiPrPh2)2] (25): This compound was prepared as described for 24,
(27): A solution of 8 (93 mg, 0.15 mmol) in CH2Cl2 (5 mL) was
with 9 (99 mg, 0.15 mmol) and phenylacetylene (32 µL, 0.30 mmol)
treated at Ϫ20 °C with 3-chloro-1-butyne (13 µL, 0.15 mmol), lead-
as starting materials. Pale-yellow solid; yield 109 mg (84%); m.p. 78 ing to a rapid change of color from dark-red to yellow. After warm-
°C (dec.). IR (KBr): ν(CϵC) ϭ 2050, ν(CϭC) ϭ 1580, ν(OCOas) ϭ ing the solution to room temperature, the solvent was evaporated
1
1485, ν(OCOsym) ϭ 1435 cmϪ1. H NMR (200 MHz, C6D6): δ ϭ in vacuo. A yellow solid was obtained which was washed twice with
8.02Ϫ6.83 (m, 30 H, C6H5), 5.96, 5.49 (both s, 1 H each, ϭCH2), 1-mL portions of acetone (0 °C) and dried; yield 93 mg (88%);
3
1
3.54 (m, 2 H, PCHCH3), 1.52 (dvt, N ϭ 10.2, JH,H ϭ 7.1 Hz, 6 m.p. 124 °C (dec.). IR (KBr): ν(OCOas) ϭ 1460 cmϪ1. H NMR
H, PCHCH3), 1.08 (dvt, N ϭ 14.8, 3JH,H ϭ 7.5 Hz, 6 H, PCHCH3),
(400 MHz, C6D6): δ ϭ 7.88Ϫ6.75 (m, 20 H, C6H5), 4.96 (dq,
1.73 [s, 9 H, C(CH3)3]. 13C NMR (100.6 MHz, C6D6): δ ϭ 190.3 3JH,H ϭ 6.8, JH,H ϭ 6.4 Hz, 1 H, ϭCHCH3), 4.71 (m, 1 H,
4
(s, O2C), 150.5 [dt, 1JRh,C ϭ 28.7, 2JP,C ϭ 18.5 Hz, RhC(ϭCH2)Ph], RhCH), 3.42, 3.23 (both m, 2 H, PCHCH3), 2.15 (s, 3 H, CO2CH3),
2
3
3
5
135.5Ϫ125.4 (m, C6H5), 125.7 (dt, JRh,C ϭ 4.4, JP,C ϭ 5.1 Hz, ϭ
1.53 (dd, JH,H ϭ 6.8, JH,H ϭ 2.7 Hz, 3 H, ϭCHCH3), 1.15 (dd,
2
3
3
3
CH2), 109.3 (dt, JRh,C ϭ 8.7, JP,C ϭ 4.7 Hz, ϵCPh), 99.9 (dt, 3JH,H ϭ 16.1, JP,H ϭ 7.0 Hz, 3 H, PCHCH3), 1.03 (dd, JH,H
ϭ
1JRh,C ϭ 50.1, 2JP,H ϭ 18.5 Hz, RhCϵCPh), 39.4 [s, C(CH3)3], 27.1
14.3, JP,H ϭ 7.0 Hz, 3 H, PCHCH3), 1.02 (dd, JH,H ϭ 16.0,
3
3
3
3
[s, C(CH3)3], 26.4 (vt, N ϭ 25.4 Hz, PCHCH3), 19.3, 19.0 (both s,
3JP,H ϭ 6.8 Hz, 3 H, PCHCH3), 0.89 (dd, JH,H ϭ 15.1, JP,H
ϭ
PCHCH3). 31P NMR (81.0 MHz, C6D6): δ ϭ 29.5 (d, JRh,P
ϭ
6.8 Hz, 3 H, PCHCH3). 13C NMR (100.6 MHz, C6D6): δ ϭ 198.1
1
1386
Eur. J. Inorg. Chem. 2002, 1377Ϫ1389

Rhodium Complexes with [Rh(PiPr2Ph)2] and [Rh(PiPrPh2)2] as Molecular Units
FULL PAPER
3
(s, RhCHϭC), 189.4 (s, O2CCH3), 134.6 (d, JP,C ϭ 7.5 Hz, meta-
108 mg (92%) from 28 and 110 mg (94%) from 29. IR (C6H6):
C of Ph), 134.3 (d, 3JP,C ϭ 6.6 Hz, meta-C of Ph), 133.9 (d, 3JP,C ϭ ν(CϵC) ϭ 2100, ν(CϭO) ϭ 1700 cmϪ1
7.4 Hz, meta-C of Ph), 133.7 (d, JP,C ϭ 6.3 Hz, meta-C of Ph),
129.3, 129.0, 128.8, 128.5 (all s, para-C of Ph), 126.1 (d, JP,C
.
1H NMR (400 MHz,
3
C6D6): δ ϭ 8.16Ϫ6.66 (m, 25 H, C6H5), 6.04 (s, 1 H, ϭ
CHCO2CH3), 3.98 (m, 2 H, PCHCH3), 3.12, 2.99 (both s, 3 H
2
ϭ
2
3
8.7 Hz, ortho-C of Ph), 125.9 (d, JP,C ϭ 9.0 Hz, ortho-C of Ph), each, CO2CH3), 1.44 (dvt, N ϭ 15.2, JH,H ϭ 7.8 Hz, 6 H,
125.5 (d, 2JP,C ϭ 10.0 Hz, ortho-C of Ph), 125.4 (d, 1JP,C ϭ 50.0 Hz, PCHCH3), 1.15 (dvt, N ϭ 14.6, JH,H ϭ 7.2 Hz, 6 H, PCHCH3).
3
1
1
ipso-C of Ph), 125.4 (d, JP,C ϭ 52.1 Hz, ipso-C of Ph), 125.3 (d,
31P NMR (162.0 MHz, C6D6): δ ϭ 18.9 (d, JRh,P ϭ 94.3 Hz);
C44ClH46O4P2Rh (839.2): calcd. C 62.98, H 5.53; found C 63.04,
H 6.00.
2JP,C ϭ 10.2 Hz, ortho-C of Ph), 124.5 (d, JP,C ϭ 46.0 Hz, ipso-C
1
1
1
of Ph), 124.4 (d, JP,C ϭ 48.2 Hz, ipso-C of Ph), 87.4 (dt, JRh,C
ϭ
17.7, 2JP,C ϭ 10.7 Hz, RhCH), 83.0 (s, ϭCHCH3), 25.9 (d, JP,C
ϭ
1
Preparation of trans-[RhCl{η2-PhCϵCC(CO2Me)؍CHCO2Me}
(PiPrPh2)2] (31): A solution of 30 (109 mg, 0.13 mmol) was stirred
for 1 h at 60 °C. A change of color from red to orange occurred.
After cooling the solution to room temperature, the solvent was
removed in vacuo, and the residue was extracted with acetone
(20 mL). The extract was dried in vacuo to give an orange solid
which was washed twice with 1-mL portions of acetone (0 °C) and
dried; yield 82 mg (75%); m.p. 104 °C (dec.). IR (KBr): ν(CϵC) ϭ
1835, ν(CϭO) ϭ 1704, ν(CϭC) ϭ 1565 cmϪ1. 1H NMR (200 MHz,
C6D6): δ ϭ 8.19Ϫ6.91 (m, 25 H, C6H5), 6.70 (s, 1 H, ϭ
CHCO2CH3), 3.48, 3.32 (both s, 3 H each, CO2CH3), 3.10 (m, 2
H, PCHCH3), 1.35 (dvt, N ϭ 15.0, 3JH,H ϭ 7.3 Hz, 6 H, PCHCH3),
1
25.9 Hz, PCHCH3), 25.7(s, O2CCH3), 25.4 (d, JP,C ϭ 26.5 Hz,
PCHCH3), 17.9, 17.7, 16.9, 16.7 (all s, PCHCH3), 13.3 (s, ϭ
CHCH3). 31P NMR (81.0 MHz, C6D6): δ(A) ϭ 51.8, δ(B) ϭ 51.3
(ABX spin system, JA,B ϭ 32.0 Hz, JA,X ϭ JB,X ϭ 139.4 Hz). MS
(70 eV, e-spray): m/z ϭ 671 [Mϩ Ϫ Cl]. C36H42ClO2P2Rh (707.0):
calcd. C 61.16, H 5.99, Rh 14.55; found C 61.14, H 6.19, Rh 14.21.
Preparation
of
[Rh(κ2-O2CCH3)(CϵCPh){(E)-C(CO2Me)؍
CHCO2Me}(PiPrPh2)2] (28): A solution of 21 (106 mg, 0.14 mmol)
in CH2Cl2 (5 mL) was treated at Ϫ20 °C with phenylacetylene (16
µL, 0.14 mmol) and stirred for 5 min at Ϫ20 °C. After a few se-
conds a change of color from yellow to red occurred, followed by
a subsequent change of color in the opposite direction. After
warming the solution to room temperature, the solvent was evapor-
ated in vacuo and the residue extracted with acetone (20 mL). The
extract was dried in vacuo to give a pale-yellow solid which was
washed twice with 1-mL portions of acetone (0 °C) and dried; yield
99 mg (82%); m.p. 140 °C (dec.). IR (KBr): ν(CϵC) ϭ 2100, ν(Cϭ
1.19 (dvt, N ϭ 15.4, JH,H ϭ 7.3 Hz, 6 H, PCHCH3). 13C NMR
3
(100.6 MHz, C6D6): δ ϭ 166.5, 165.7 (both s, CO2), 130.9 (s, ϭ
CCO2CH3), 173.0Ϫ124.9 (m, C6H5), 120.2 (s, ϭCHCO2CH3),
108.5 (dt, 1JRhC ϭ 15.3, 2JP,C ϭ 2.9 Hz, PhCϵC), 81.7 (dt, 1JRhC ϭ
2
16.2, JP,C ϭ 2.0 Hz, PhCϵC), 51.9, 51.5 (both s, CO2CH3), 25.4
(vt, N ϭ 23.5 Hz, PCHCH3), 19.9, 19.3 (both s, PCHCH3). 31P
O) ϭ 1695, ν(OCO) ϭ 1570 cmϪ1 1H NMR (200 MHz, C6D6):
.
δ ϭ 8.11Ϫ6.99 (m, 25 H, C6H5), 6.00 (s, 1 H, ϭCHCO2CH3), 3.80
(s, 3 H, CO2CH3), 3.52 (m, 2 H, PCHCH3), 3.37 (s, 3 H, CO2CH3),
1
NMR (81.0 MHz, C6D6): δ ϭ 36.6 (d, JRhP ϭ 117.7 Hz). MS
(70 eV, e-spray): m/z ϭ 803 [Mϩ Ϫ Cl]. C44H46ClO4P2Rh (839.2):
calcd. C 62.98, H 5.53; found C 63.03, H 6.01.
3
1.40 (dvt, N ϭ 15.4, JH,H ϭ 7.7 Hz, 6 H, PCHCH3), 0.99 (dvt,
N ϭ 14.6, 3JH,H ϭ 7.3 Hz, 6 H, PCHCH3), 0.98 (s, 3 H, O2CCH3).
Reaction of 31 with CO: A slow stream of CO was passed through
a solution of 31 (84 mg, 0.10 mmol) in CH2Cl2 (10 mL) at room
temperature for 10 s. An instantaneous change of color from or-
ange to yellow occurred. The 1H NMR spectrum of the solution
indicated that the enyne 33 was formed along with 32.[23] The solv-
ent was evaporated in vacuo, the remaining yellow solid was
washed twice with 1-mL portions of acetone (0 °C) and identified
as 32; yield 62 mg (98%).
31P NMR (81.0 MHz, C6D6): δ ϭ 34.3 (d, JRh,P ϭ 97.4 Hz).
1
C46H49O6P2Rh (862.7): calcd. C 64.04, H 5.72, Rh 11.93; found C
63.51, H 5.66, Rh 11.87.
Preparation of [Rh{κ2-O2CC(CH3)3}(CϵCPh){(E)-C(CO2Me)؍
CHCO2Me}(PiPrPh2)2] (29): This compound was prepared as de-
scribed for 28, with 22 (96 mg, 0.12 mmol) and phenylacetylene (14
µL, 0.12 mmol) as starting materials. Pale-yellow solid; yield 93 mg
(86%); m.p. 116 °C (dec.). IR (KBr): ν(CϵC) ϭ 2100, ν(CϭO) ϭ
Preparation of trans-[RhCl(CO)(PiPrPh2)2] (32): A slow stream of
CO was passed through a suspension of 3 (48 mg, 0.04 mmol) in
toluene (10 mL) at room temperature for 10 min. A change of color
from violet to yellow occurred. After evaporation of the solvent in
vacuo, the yellow solid was washed twice with 1-mL portions of
acetone (0 °C) and dried; yield 50 mg (99%); m.p. 140 °C. IR
1695, ν(OCO) ϭ 1570 cmϪ1 1H NMR (200 MHz, C6D6): δ ϭ
.
7.98Ϫ7.03 (m, 25 H, C6H5), 6.04 (s, 1 H, ϭCHCO2CH3), 3.89 (s,
3 H, CO2CH3), 3.54 (m, 2 H, PCHCH3), 3.40 (s, 3 H, CO2CH3),
1.33 (dvt, N ϭ 15.0, JH,H ϭ 7.5 Hz, 6 H, PCHCH3), 1.04 (dvt,
3
3
N ϭ 14.4, JH,H ϭ 7.5 Hz, 6 H, PCHCH3), 0.70 [s, 9 H, C(CH3)3].
(KBr): ν(CO) ϭ 1960 cmϪ1 1H NMR (200 MHz, C6D6): δ ϭ
.
13C NMR (100.6 MHz, C6D6): δ ϭ 192.1 [s, O2CC(CH3)3], 173.1,
1
2
7.79Ϫ6.96 (m, 20 H, C6H5), 3.48 (m, 2 H, PCHCH3), 1.10 (dvt,
162.2 (both s, CO2CH3), 162.2 [dt, JRh,C ϭ 33.9, JP,C ϭ 9.5 Hz,
N ϭ 15.5, 3JH,H ϭ 7.5 Hz, 12 H, PCHCH3). 31P NMR (81.0 MHz,
2
RhC(CO2CH3)], 136.5Ϫ125.4 (m, C6H5), 120.5 (dt, JRh,C ϭ 4.3,
1
2
3
3JP,C ϭ 4.3 Hz, ϭCHCO2CH3), 106.6 (dt, JRh,C ϭ 8.6, JP,C
ϭ
C6D6): δ ϭ 41.0 (d, JRh,P ϭ 123.5 Hz). C31H34ClOP2Rh (622.9):
calcd. C 59.77, H 5.50, Rh 16.52; found C 60.21, H 5.99, Rh 16.74.
1
2
1.9 Hz, ϵCC6H5), 100.2 (dt, JRhC ϭ 48.6, JP,C ϭ 20.5 Hz,
RhCϵC), 51.0, 50.3 (both s, CO2CH3), 39.6 [s, C(CH3)3], 27.0 (vt,
Preparation of [Rh{κ1-O2S(O)-p-Tol}(؍C؍CHPh)(PiPr2Ph)2] (34):
A solution of 12 (106 mg, 0.16 mmol) in toluene (2 mL) was treated
with phenylacetylene (19 µL, 0.16 mmol) and stirred for 3 h at
room temperature. A change of color from red to violet occurred.
The solvent was evaporated in vacuo and the residue extracted with
N ϭ 25.3 Hz, PCHCH3) 26.7 [s, C(CH3)3], 20.1, 19.1 (both s,
1
PCHCH3). 31P NMR (81.0 MHz, C6D6): δ ϭ 31.8 (d, JRh,P
ϭ
97.2 Hz). C49H54O6P2Rh (903.8): calcd. C 65.12, H 6.02; found C
65.44, H 6.18.
Preparation
of
[RhCl(CϵCPh){(E)-C(CO2Me)؍CHCO2Me} ether (25 mL). After drying the extract in vacuo, the remaining
violet solid was washed twice with 10-mL portions of pentane (0
(PiPrPh2)2] (30): A solution of either 28 (121 mg, 0.14 mmol) or 29
(127 mg, 0.14 mmol) in acetone (5 mL) was treated with freshly °C) and dried; yield 120 mg (98%); m.p. 67 °C (dec.). IR (CH2Cl2):
distilled Me3SiCl (18 µL, 0.14 mmol) and stirred for 10 min at Ϫ20
°C. A rapid change of color from pale-yellow to red occurred. After
warming the solution to room temperature and evaporating the
solvent in vacuo, a red, thermally labile oil was obtained; yield
ν(CϭC) ϭ 1650 cmϪ1. 1H NMR (200 MHz, C6D6): δ ϭ 7.75Ϫ6.56
(m, 19 H, C6H5 and C6H4), 2.82 (m, 4 H, PCHCH3), 1.93 (s, 3 H,
C6H4CH3), 1.40 (dvt, N ϭ 16.4, 3JH,H ϭ 6.9 Hz, 12 H, PCHCH3),
3
4
1.09 (dt, JRh,H ϭ 1.5, JP,H ϭ 3.5 Hz, 1 H, ϭCHPh), 0.93 (dvt,
Eur. J. Inorg. Chem. 2002, 1377Ϫ1389
1387

H. Werner, F. Kukla, P. Steinert
FULL PAPER
3
N
ϭ
13.9, JH,H
ϭ
9.1 Hz, 12 H, PCHCH3). 13C NMR
1.62 (s, 1 H, OH), 1.45 [s, 6 H, C(CH3)2OH], 1.36 (dvt, N ϭ 16.1,
1
3
(100.6 MHz, C6D6): δ ϭ 306.9 (dt, JRh,C ϭ 58.4, 2JP,C ϭ 18.1 Hz, 3JH,H ϭ 7.3 Hz, 12 H, PCHCH3), 1.06 (dvt, N ϭ 13.5, JH,H
ϭ
RhϭCϭC), 143.7, 139.4, 134.9, 129.9, 128.6, 128.5, 127.9, 127.7, 6.2 Hz, 12 H, PCHCH3), 0.92 [s, 6 H, C(CH3)2OH], 0.21 (dt,
4
126.8, 126.2, 125.3, 124.6 (all s, C6H5 and C6H4), 113.4 (dt, 3JRh,H ϭ 0.7, JP,H ϭ 3.7 Hz, 1 H, ϭCHR), signal of the second
2JRh,C ϭ 15.3, 3JP,C ϭ 6.7 Hz, RhϭCϭC), 30.4 (s, C6H4CH3), 23.2 OH proton not found. 31P NMR (81.0 MHz, C6D6): δ ϭ 45.7 (d,
(vt, N ϭ 22.3 Hz, PCHCH3), 20.0, 18.5 (both s, PCHCH3). 31P
NMR (81.0 MHz, C6D6): δ ϭ 43.3 (d, JRh,P ϭ 143.9 Hz). found C 61.59, H 8.10.
1JRh,P ϭ 142.4 Hz). C34H53O2P2Rh (658.7): calcd. C 62.00, H 8.11;
1
C39H51O3RhS (764.8): calcd. C 61.25, H 6.72; found C 60.87, H
6.68.
Preparation of [Rh(CϵCCMe2OH)(؍C؍CHPh)(PiPr2Ph)2] (38):
A solution of 34 (115 mg, 0.15 mmol) in a 1:1 mixture of toluene
and freshly distilled triethylamine (5 mL) was treated at Ϫ50 °C
with HCϵCCMe2(OH) (15 µL, 0.15 mmol) and stirred for 5 min
at this temperature. A change of color from violet to dark green
occurred. After warming the solution to room temperature, the
solvent was evaporated in vacuo. The residue was extracted with
25 mL of ether (0 °C) and the extract was dried in vacuo. The
residue was dissolved in 3 mL of acetone (0 °C) and the solution
stored for 3 min at this temperature. Dark green crystals precipit-
ated, which were filtered, washed twice with 1-mL portions of acet-
one (0 °C) and dried; yield 40 mg (39%); m.p. 98 °C (dec.). IR
(KBr): ν(OH) ϭ 3350, ν(CϵC) ϭ 2060, ν(CϭC) ϭ 1635 cmϪ1. 1H
NMR (200 MHz, C6D6): δ ϭ 7.44Ϫ7.04 (m, 15 H, C6H5), 3.12 (m,
Preparation
of
[Rh{κ1-O2S(O)-p-Tol}(؍C؍CHCMe2OH)-
(PiPr2Ph)2] (35): This compound was prepared as described for
34, with 12 (106 mg, 0.16 mmol) and HCϵCCMe2(OH) (16 µL,
0.16 mmol) as starting materials; reaction time 1 h. Violet solid;
yield 113 mg (95%); m.p. 58 °C (dec.). IR (CH2Cl2): ν(CϭC) ϭ
1635 cmϪ1. H NMR (200 MHz, C6D6): δ ϭ 7.59Ϫ6.81 (m, 14 H,
1
C6H5 and C6H4), 2.87 (s, 3 H, C6H4CH3), 2.57 (m, 4 H, PCHCH3),
1.43 (dvt, N ϭ 16.5, JH,H ϭ 7.3 Hz, 12 H, PCHCH3), 1.23 [s, 6
H, C(CH3)2OH], 1.05 (dvt, N ϭ 13.9, JH,H ϭ 6.9 Hz, 12 H,
3
3
3
4
PCHCH3), 1.00 (dt, JRh,H ϭ 0.6, JP,H ϭ 3.1 Hz, 1 H, ϭCHR),
signal of OH proton not found. 13C NMR (100.6 MHz, C6D6): δ ϭ
308.2 (dt, 1JRh,C ϭ 59.9, 2JP,C ϭ 16.4 Hz, RhϭCϭC), 143.9, 139.5,
135.2, 133.5, 130.1, 128.7, 128.1, 127.0 (all s, C6H5 and C6H4),
3
4 H, PCHCH3), 1.60 (dvt, N ϭ 15.7, JH,H ϭ 8.0 Hz, 12 H,
2
3
3
115.7 (dt, JRh,C ϭ 15.3, JP,C ϭ 5.9 Hz, RhϭCϭC), 43.0 [s,
C(CH3)2OH], 31.8 (s, C6H4CH3), 28.2 [s, C(CH3)2OH], 25.0 (vt,
PCHCH3), 1.20 (dvt, N ϭ 13.3, JH,H ϭ 6.6 Hz, 12 H, PCHCH3),
3
4
1.07 [s, 6 H, C(CH3)2OH], 0.96 (dt, JRh,H ϭ 0.8, JP,H ϭ 3.6 Hz,
1 H, ϭCHR), signal of OH proton not found. 31P NMR
(162.0 MHz, C6D6): δ ϭ 45.9 (d, 1JRh,P ϭ 141.0 Hz). C37H51OP2Rh
(676.7): calcd. C 65.68, H 7.60; found C 65.33, H 7.48.
N ϭ 25.9 Hz, PCHCH3), 20.2, 18.7 (both s, PCHCH3). 31P NMR
1
(81.0 MHz, C6D6):
C36H53O4P2RhS (746.7): calcd. 57.90, H 7.15; found C 58.06, H
6.97.
δ
ϭ
42.4 (d, JRh,P
ϭ
143.9 Hz).
Preparation of trans-[Rh{(Z)-C(؍CHPh)CϵCPh}(CO)(PiPr2Ph)2]
(39): A slow stream of CO was passed through a solution of 36
(97 mg, 0.14 mmol) in CH2Cl2 (5 mL) at Ϫ20 °C for 10 s. A change
of color from dark green to yellow occurred. After warming the
solution to room temperature, the solvent was evaporated in vacuo.
The residue was extracted with 25 mL of acetone (10 °C) and the
extract was dried in vacuo. The remaining yellow solid was washed
twice with 1-mL portions of acetone (0 °C) and dried; yield 87 mg
Preparation of [Rh(CϵCPh)(؍C؍CHPh)(PiPr2Ph)2] (36): a) A so-
lution of 12 (100 mg, 0.15 mmol) in a 1:1 mixture of toluene and
freshly distilled triethylamine (5 mL) was treated with phenylacetyl-
ene (34 µL, 0.30 mmol) and stirred for 5 min at Ϫ20 °C. A smooth
change of color from red to dark green occurred. After warming
the solution to room temperature, the solvent was evaporated in
vacuo and the residue was extracted with 25 mL of ether (0° C).
The extract was dried in vacuo, the remaining residue was dissolved
in 5 mL of pentane (0° C) and the solution stored at this temper-
ature. Turquoise crystals precipitated after 1 min, which were fil-
tered, washed twice with 1-mL portions of pentane (0 °C) and
dried; yield 35 mg (34%).
(86%); m.p. 144 °C (dec.). IR (KBr): ν(CϵC) ϭ 2120, ν(CO) ϭ
3
1955 cmϪ1
.
1H NMR (200 MHz, C6D6): δ ϭ 8.07 (dt, JRh,H
ϭ
4
2.2, JP,H ϭ 9.5 Hz, 1 H, ϭCHPh), 7.81Ϫ6.94 (m, 20 H, C6H5),
2.78, 2.41 (both m, 2 H each, PCHCH3), 2.26 (dvt, N ϭ 15.9,
3
3JH,H ϭ 7.0 Hz, 6 H, PCHCH3), 1.13 (dvt, N ϭ 15.0, JH,H
ϭ
3
b) A solution of 34 (107 mg, 0.14 mmol) in a 1:1 mixture of toluene
and freshly distilled triethylamine (5 mL) was treated at Ϫ50 °C
with phenylacetylene (15 µL, 0.14 mmol). A quick change of color
from violet to dark green occurred. After warming the solution to
room temperature, it was worked up as described for a). Turquoise
crystals were obtained; yield 54 mg (56%); m.p. 78 °C (dec.). IR
7.3 Hz, 6 H, PCHCH3), 0.87 (dvt, N ϭ 15.2, JH,H ϭ 6.6 Hz, 6 H,
3
PCHCH3), 0.65 (dvt, N ϭ 16.1, JH,H ϭ 7.3 Hz, 6 H, PCHCH3).
31P NMR (81.0 MHz, C6D6): δ ϭ 41.4 (d, JRh,P ϭ 145.3 Hz).
1
C41H49OP2Rh (722.7): calcd. C 68.14, H 6.83; found C 67.80, H
7.28.
(KBr): ν(CϵC) ϭ 2060, ν(CϭC) ϭ 1635 cmϪ1 1H NMR
.
Preparation of trans-[Rh{(Z)-C(؍CHCMe2OH)CϵCCMe2OH}
(CO)(PiPr2Ph)2] (40): This compound was prepared as described
for 39, with 37 (86 mg, 0.13 mmol) and CO as starting materials.
Yellow solid; yield 75 mg (84%); m.p. 80 °C (dec.). IR (KBr):
ν(CϵC) ϭ 2160, ν(CO) ϭ 1955 cmϪ1. 1H NMR (200 MHz, C6D6):
(200 MHz, C6D6): δ ϭ 7.78Ϫ6.78 (m, 20 H, C6H5), 2.87 (m, 4 H,
3
PCHCH3), 1.42 (dvt, N ϭ 17.9, JH,H ϭ 6.9 Hz, 12 H, PCHCH3),
3
4
1.28 (dt, JRh,H ϭ 0.7, JP,H ϭ 3.7 Hz, 1 H, ϭCHPh), 1.06 (dvt,
N ϭ 13.9, 3JH,H ϭ 6.9 Hz, 12 H, PCHCH3). 31P NMR (81.0 MHz,
C6D6): δ ϭ 46.8 (d, 1JRh,P ϭ 141.0 Hz). C40H49P2Rh (694.7): calcd.
C 69.16, H 7.11, Rh 14.81; found C 68.62, H 7.08, Rh 14.40.
3
4
δ ϭ 8.20Ϫ7.34 (m, 10 H, C6H5), 7.18 (dt, JRh,H ϭ 2.6, JP,H
ϭ
2.2 Hz, 1 H, ϭCHR), 4.64 (s, 1 H, OH), 3.00, 2.73 (both m, 2 H
each, PCHCH3), 2.00 (s, 1 H, OH), 1.97 [s, 6 H, C(CH3)2OH],
Preparation of [Rh(CϵCCMe2OH)(؍C؍CHCMe2OH)(PiPr2Ph)2]
(37): This compound was prepared as described for 36, either ac-
cording to method a) from 12 (106 mg, 0.16 mmol) and
HCϵCCMe2(OH) (32 µL, 0.32 mmol) or according to method b)
from 35 (106 mg, 0.14 mmol) and HCϵCCMe2(OH) (14 µL,
0.14 mmol). Dark green solid; yield 47 mg (45%) for a) and 63 mg
(68%) for b); m.p. 78 °C (dec.). IR (KBr): ν(OH) ϭ 3555, 3540,
3
1.70 (dvt, N ϭ 16.5, JH,H ϭ 9.5 Hz, 6 H, PCHCH3), 1.46 [s, 6 H,
C(CH3)2OH], 1.42 (dvt, N ϭ 13.9, 3JH,H ϭ 8.4 Hz, 6 H, PCHCH3),
3
1.35 (dvt, N ϭ 12.1, JH,H ϭ 6.6 Hz, 6 H, PCHCH3), 1.25 (dvt,
3
N ϭ 13.9, JH,H ϭ 7.3 Hz, 6 H, PCHCH3). 31P NMR (81.0 MHz,
1
C6D6): δ ϭ 39.1 (d, JRh,P ϭ 142.4 Hz). C35H53O3P2Rh (686.7):
calcd. C 61.22, H 7.78; found C 61.53, H 7.72.
ν(CϵC) ϭ 2060, ν(CϭC) ϭ 1625 cmϪ1 1H NMR (200 MHz, Preparation of trans-[Rh{(Z)-C(؍CHPh)CϵCCMe2OH}(CO)-
.
C6D6): δ ϭ 7.44Ϫ7.04 (m, 10 H, C6H5), 2.88 (m, 4 H, PCHCH3),
(PiPr2Ph)2] (41): This compound was prepared as described for 39,
1388
Eur. J. Inorg. Chem. 2002, 1377Ϫ1389

Rhodium Complexes with [Rh(PiPr2Ph)2] and [Rh(PiPrPh2)2] as Molecular Units
FULL PAPER
[6]
H. Werner, A. Hampp, K. Peters, E. M. Peters, L. Walz, H. G.
von Schnering, Z. Naturforsch., Teil B 1990, 45, 1548Ϫ1558.
K. Vrieze, H. C. Volger, P. W. N. M. van Leeuwen, Inorg. Chim.
Acta, Rev. 1977, 16, 211Ϫ239.
with 38 (101 mg, 0.15 mmol) and CO as starting materials. Yellow
oil; yield 40 mg (38%). IR (KBr): ν(CϵC) ϭ 2070, ν(CO) 1950
cmϪ1. 1H NMR (200 MHz, C6D6): δ ϭ 7.93Ϫ7.25 (m, 15 H, C6H5),
[7]
3
4
7.20 (dt, JRh,H ϭ 2.4, JP,H ϭ 2.2 Hz, 1 H, ϭCHR), 4.53 (s, 1 H,
[8] [8a]
S. D. Robinson, M. F. Uttley, J. Chem. Soc., Dalton Trans.
OH), 2.77, 2.51 (both m, 2 H each, PCHCH3), 1.46 (dvt, N ϭ 16.5,
[8b]
1973, 1912Ϫ1920.
G. B. Deacon, R. J. Phillips, Coord.
3
3JH,H ϭ 6.9 Hz, 6 H, PCHCH3), 1.25 (dvt, N ϭ 15.7, JH,H
ϭ
Chem. Rev. 1980, 33, 227Ϫ250. [8c] D. A. Tocher, R. O. Gould,
T. A. Stephenson, M. A. Bennett, J. P. Ennett, T. W. Matheson,
L. Sawyer, V. K. Shah, J. Chem. Soc., Dalton Trans. 1983,
1571Ϫ1581.
6.9 Hz, 6 H, PCHCH3), 1.23 [s, 6 H, C(CH3)2OH], 1.12 (dvt, N ϭ
13.5, 3JH,H ϭ 6.9 Hz, 6 H, PCHCH3), 1.00 (dvt, N ϭ 14.3, 3JH,H ϭ
6.6 Hz, 6 H, PCHCH3). 31P NMR (81.0 MHz, C6D6): δ ϭ 39.1 (d,
1JRh,P ϭ 140.9 Hz). C38H51O2P2Rh (704.7): calcd. C 64.77 H 7.29,
Rh 14.60; found C 64.68 H 7.34, Rh 14.22.
[9] [9a]
D. N. Lawson, G. Wilkinson, J. Chem. Soc. 1965,
1900Ϫ1907. [9b] F. Bianchi, M. C. Gallazzi, L. Porri, P. Diversi,
J. Organomet. Chem. 1980, 202, 99Ϫ105. [9c] M. A. Arthurs, S.
[9d]
Determination of the X-ray Crystal Structure of 27: Single crystals
were grown upon diffusion of ether into a saturated solution of 27
in CH2Cl2/methylcyclohexane. Crystal data (from 23 reflections,
10° Ͻ Θ Ͻ 14°): monoclinic; space group P21/c (No. 14); a ϭ
M. Nelson, J. Coord. Chem. 1983, 13, 29Ϫ40.
A. Martin, M. A. Esteruelas, E. Sola, J. L. Serrano, L. A. Oro,
Organometallics 1991, 10, 1794Ϫ1799.
H. Werner, M. Bosch, M. E. Schneider, C. Hahn, F. Kukla,
M. Manger, B. Windmüller, B. Weberndörfer, M. Laubender,
J. Chem. Soc., Dalton Trans. 1998, 3549Ϫ3558.
M. Schäfer, J. Wolf, H. Werner, J. Organomet. Chem. 1995,
485, 85Ϫ100.
H. Werner, M. Schäfer, J. Wolf, K. Peters, H. G. von Schnering,
Angew. Chem. 1995, 107, 213Ϫ215; Angew. Chem. Int. Ed.
Engl. 1995, 34, 191Ϫ194.
H. Werner, M. Schulz, B. Windmüller, Organometallics 1995,
14, 3659Ϫ3668.
F. J. Lahoz,
[10]
˚
10.496(5), b ϭ 17.455(5), c ϭ 18.629(7) A, β ϭ 97.33(2)°; V ϭ
3
3385(2) A , Z ϭ 4; dcalcd. ϭ 1.387 g cmϪ3; µ(Mo-Kα) ϭ 7.0 cmϪ1
;
˚
[11]
[12]
crystal size 0.23 ϫ 0.38 ϫ 0.48 mm; EnrafϪNonius CAD4, Mo-Kα
˚
radiation (0.71073 A), graphite monochromator; T ϭ 293(2) K; Θ-
scan, max. 2Θ ϭ 47.94°; 5011 reflections measured, 4691 independ-
ent, 3135 with I Ͼ 2σ(I). Intensity data were corrected for Lorentz
and polarization effects and an empirical absorption correction was
applied. The structure was solved by direct method (SHELXS-
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atoms were calculated according to ideal geometry and refined with
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CCDC-175652 contains the supplementary crystallographic data
for this paper. These data can be obtained free of charge at
www.ccdc.cam.ac.uk/conts/retrieving.html [or from the Cambridge
Crystallographic Data Centre, 12, Union Road, Cambridge
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This work was supported by the Deutsche Forschungsgemeinschaft
(SFB 347) and the Fonds der Chemischen Industrie. We thank Mrs.
R. Schedl and Mr. C. P. Kneis for elemental analysis and DTA
measurements, Mrs. M.-L. Schäfer and Dr. W. Buchner for NMR
spectra, Dr. G. Lange and Mr. F. Dadrich for mass spectra, and
Mr. C. D. Brandt for drawing the molecular diagram.
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