3-metalla-1,2-dioxolanes and their reactivity

FULL PAPER

3-Metalla-1,2-dioxolanes and Their Reactivity

Monique Krom,^[a]Theo P. J. Peters,^[a]Ruud G. E. Coumans,^[a]Timo J. J. Sciarone,^[a]

Johan Hoogboom,^[a]Sandra I. ter Beek,^[a]Paul P. J. Schlebos,^[a]Jan M. M. Smits,^[a]

[a]

´

Rene de Gelder, and Anton W. Gal*

Keywords: Formylmethyl complexes / Metallacycles / N ligands / Oxygenations / Rhodium

The ethene complexes [M^I(CH₂CH₂)]⁺(M = Ir, Rh) can be

oxygenated by molecular oxygen or air in the solid state, to

3-metalla-1,2-dioxolanes rearrange, both in the solid state

and in solution, to formylmethyl hydroxy complexes on

exposure to photons or protons. The isomeric 3-rhoda-1,2-

dioxolanes [(tpa)Rh(CH₂CH₂OO-κ²C¹,O²)]⁺8a⁺and 8b⁺dif-

fer in reactivity. On exposure of a solution of 8aPF₆/8bPF₆

to glass-filtered daylight, isomer 8b⁺rearranges to form the

formylmethyl hydroxy complex 9b⁺. This rearrangement is

three times faster than the rearrangement of 8a⁺to 9a⁺. The

form

isolable

unsubstituted

3-metalla-1,2-dioxolanes

[M^III(CH₂CH₂OO-κ²C¹,O²)]⁺. Such selectivity could not be

achieved in solution. The stereoselectivity of the oxygenation

process is highly dependent on the ligand, the metal and the

counterion used. Oxygenation of [(tpa)M(CH₂CH₂)]PF₆

{tpa = tri(2-pyridylmethyl)amine; 4PF₆, 7PF₆} results in the

formation of two isomeric 3-metalladioxolanes, whereas oxy- iridadioxolanes are much more reactive than the correspon-

genation of [(tpa)M(CH₂CH₂)]BPh₄(4BPh₄, 7BPh₄) only

yields one isomer. Furthermore, oxygenation of [(Metpa)-

Rh(CH₂CH₂)]PF₆{14PF₆, Metpa = [(6-methyl-2-pyridyl)me-

thyl]bis(2-pyridylmethyl)amine} proved to be much slower

than that of [(tpa)Rh(CH₂CH₂)]PF₆(7PF₆). The solid propene

complex [(tpa)Rh(CH₂CHCH₃)]BPh₄(23BPh₄) loses propene

on reaction with molecular oxygen, and selectively forms the

peroxo complex [(tpa)Rh(η²-O₂)]BPh₄(24BPh₄). The obtained

ding rhodadioxolanes, whereas the iridium formylmethyl hy-

droxy complexes are less reactive than the corresponding

rhodium formylmethyl hydroxy complexes. The tpa formyl-

methyl hydroxy complexes react reversibly with carbon di-

oxide to form formylmethyl hydrogen carbonate complexes.

( Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim,

Germany, 2003)

Introduction

epoxidation^[1dϪ1f]and oxidation to ketones.^[1aϪ1c]Mimoun

et al. have proposed that the rhodium-catalyzed olefin ox-

idation proceeds via a peroxo ethene complex. Insertion of

ethene into the rhodium dioxygen bond then results in the

formation of a 3-rhoda-1,2-dioxolane complex, which sub-

sequently decomposes to acetaldehyde and a rhodium oxo

complex (Scheme 1).^[1a]

Transition metal catalyzed oxidation of olefins is one of

the most important methods of converting these readily

available and cheap starting materials into useful chemicals.

For economical and environmental reasons, molecular oxy-

gen or air are the most interesting oxidants. However, not

much is known about the mechanisms involved in transition

metal catalyzed olefin oxidations. In an attempt to investig-

ate the validity of some of the earlier proposed mechanisms,

we have investigated the oxygenation of rhodium and iri-

dium ethene complexes by air.

3-Metalla-1,2-dioxolanes (κ²-C¹,O²-2-peroxyethyl metal

complexes, see Structure) have been proposed as interme-

diates in the catalytic oxygenation of olefins by group VI

and

VIII

metals.^[1]

These

reactions

include

[a]

Department of Inorganic Chemistry, University of Nijmegen

Toernooiveld 1, 6525 ED Nijmegen, The Netherlands

Fax: (internat.) ϩ31-24355-3450

E-mail: gal@sci.kun.nl

Supporting information for this article is available on the

WWW under http://ww w .eurjic.org or from the author.

Scheme 1. Mechanism proposed by Mimoun for the rhodium cata-

lyzed oxidation of ethene to acetaldehyde^[1a]

1072  2003 WILEY-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim 1434Ϫ1948/03/0306Ϫ1072 $ 20.00ϩ.50/0 Eur. J. Inorg. Chem. 2003, 1072Ϫ1087

3-Metalla-1,2-dioxolanes and Their Reactivity

FULL PAPER

In the molybdenum catalyzed oxidation of olefins, Mim-

oun proposed that decomposition of 3-molybdena-1,2-diox-

olanes results in the formation of a molybdenum oxo com-

plex and ethylene oxide.^[1e][1f]However, calculations by

Frenking et al. have indicated that this would lead to the

formation of acetaldehyde instead of ethylene oxide.^[2]

3-Metalla-1,2-dioxolanes containing an unsubstituted 3-

metalla-1,2-dioxolane fragment [M(κ²C¹,O²-CH₂CH₂OO-)]

have not been reported before. However, tri- and tetra-sub-

stituted 3-platina-1,2-dioxolanes, with substituents that pre-

vent β-hydrogen transfer, have been obtained from the reac-

tion of [(PPh₃)₂Pt(η²-O₂)] with electron-deficient olefins,

and have been structurally characterized (1 and 2).^[3]These

substituted platinadioxolanes cannot be used as models for

the further study of proposed metalladioxolane interme-

diates.

Scheme 2. Reactivity of bis(ethene) complex 3PF₆and mono-

ethene complex 4PF₆

The structure of complex 3^ϩ, as determined by X-ray dif-

fraction, is shown in Figure 1. The complex has a trigonal

bipyramidal conformation and contains the tpa ligand in a

meridional tridentate coordination mode. This coordination

mode has not been observed before for bis(olefin) metal

complexes stabilized by bpa-type ligands {bpa ϭ bis(2-

pyridylmethyl)amine}; in such complexes the bpa-type tri-

dentate nitrogen donor ligand usually adopts a facial coor-

1

dination mode.^[6,7]The H NMR spectrum of 3^ϩat room

temperature shows four triplets and its ¹³C NMR spectrum

shows four singlets for the ethene fragments, indicating that

the fragments are not rotating, probably due to steric hind-

rance.

We now report on the synthesis of unsubstituted 3-

metalla-1,2-dioxolanes, through the oxidation of rhodium

and iridium ethene complexes by air or molecular oxygen.

Oxidation by molecular oxygen was sometimes necessary

due to the reactivity of the oxidation products towards

water or carbon dioxide from the air. Rearrangement of the

3-metalla-1,2-dioxolanes to formylmethyl hydroxy com-

plexes is also reported. Part of this work has been commun-

icated previously.^[4]

Results and Discussion

Synthesis of Ethene Complexes

Rhodium tpa Complexes

Figure 1. X-ray structure of bis(ethene) complex 3^ϩ

The complexes [(tpa)Rh(CH₂CH₂)]BPh₄{7BPh₄, tpa ϭ

tris(2-pyridylmethyl)amine} and [(Metpa)Rh(CH₂CH₂)]-

PF₆{14PF₆, Metpa ϭ [(6-methyl-2-pyridyl)methyl]bis(2-

pyridylmethyl)amine} were synthesized according to a liter-

ature procedure. NaBPh₄and KPF₆were used to precipit-

ate 7BPh₄and 14PF₆, respectively.^[5]

Rhodium N₄Me₂Complexes

To test the influence of the nitrogen donor ligand on the

reactivity of the ethene complexes, bis(ethene) complex 5^ϩ

(Scheme 3) was synthesized as the PF₆-salt from

[{(ethene)₂RhCl}₂], N₄Me₂and KPF₆. Complex 5^ϩcon-

tains the rigid macrocyclic N₄ligand, N,NЈ-dimethyl-2,11-

Iridium tpa Complexes

Bis(ethene) complexes 3BPh₄and 3PF₆were synthesized diaza[3,3](2,6)pyridinophane^[8](N₄Me₂). As mentioned

from in situ generated IrCl(C₂H₄)₄, tpa, and NaBPh₄or earlier, reaction of tpa with IrCl(C₂H₄)₄initially gives a bis-

KPF₆, respectively. Whereas a mono-ethene complex (7^ϩ) (ethene) complex, which easily and reversibly loses one

is formed for rhodium, a bis(ethene) complex is initially ob- ethene molecule. The same reaction with [{(C₂H₄)₂RhCl}₂]

tained for iridium, probably due to the better π-back-donat- only produces the mono-ethene complex 7^ϩ, even when car-

ing ability of iridium. However, an ethene molecule is easily ried out at low temperature. Rhodium apparently does not

lost from the bis(ethene) complex; when N₂is bubbled bind the second ethene molecule as strongly as iridium.

through a solution containing 3^ϩ, the mono-ethene com- Therefore, the initial formation of the bis(ethene) complex

plex 4^ϩis obtained (Scheme 2). This reaction is reversible; 5PF₆with N₄Me₂was surprising. However, 5PF₆also loses

when ethene is bubbled through a solution containing 4^ϩ, an ethene molecule easily (see below). The synthesis of 5PF₆

the bis(ethene) complex 3^ϩis obtained.

is discussed in more detail in the supporting information.

Eur. J. Inorg. Chem. 2003, 1072Ϫ1087

1073

A. W. Gal et al.

FULL PAPER

irrespective of the counterion, the selectivity is higher in

acetone than in acetonitrile.

Since a square planar [(κ³-N₄Me₂)Rh(C₂H₄)]^ϩstructure

is not possible for complex 6^ϩdue to the rigidity of the

N₄Me₂ligand, we propose that the ligand has a κ⁴-coor-

dination mode, similar to tpa in 7^ϩ.^[5]Another indication

for tetradentate coordination is the fact that the signals for

1

the NMe groups in the H NMR and ¹³C NMR spectra

are at approximately the same chemical shifts [δ(¹H) ϭ

2.15 ppm, δ(¹³C) ϭ 49.8 ppm] as the signals for the coord-

inated NMe group in 5^ϩ[δ(¹H) ϭ 2.25 ppm, δ(¹³C) ϭ

52.6 ppm].

Complex 6PF₆is not stable in solution at room temper-

ature, and decomposes within hours to a mixture of uniden-

tified products. Thus, the formation of 6PF₆is always ac-

companied by some decomposition, and analytically pure

samples of it and its oxidation products (see below) could

not be obtained.

Scheme 3. Loss of ethene from bis(ethene) complex 5PF₆

1

The H NMR and ¹³C NMR resonances of the vinylic

groups of 5^ϩare broad at room temperature, which indic-

ates the rotation of the ethene fragments. At Ϫ60 °C this

1

rotation is frozen, resulting in an ABCD-pattern in the H

NMR spectrum. X-ray quality crystals of 5PF₆were ob-

tained by crystallization from acetone/diethyl ether (v/v ϭ

1:3) over a period of nine days at Ϫ70 °C. The X-ray struc-

ture of the cation 5^ϩis shown in Figure 2. This is the first

reported X-ray structure of a bis(ethene) rhodium complex

stabilized by three nitrogen donors.

Formation of 3-Metalla-1,2-dioxolanes from Ethene

Complexes

Rhodium tpa Complexes

Oxidation of 7BPh₄by air at room temperature in solu-

tion (acetone, acetonitrile, dichloromethane) results in the

dissociation of ethene and the formation of a mixture of

unidentified products. In marked contrast, exposure of solid

7BPh₄to air for two days results in the formation of 3-

rhoda-1,2-dioxolane 8aBPh₄(Scheme 4).^[11]

A

small

amount of the hydroperoxy hydroxy complex 25BPh₄is also

formed (see below).

The ESI-MS spectrum of 8aBPh₄shows a base peak at

m/z ϭ 453, corresponding to [(tpa)Rh(CH₂CH₂) ϩ O₂]^ϩ.

The ¹H NMR spectrum shows the presence of

a

RhϪCH₂ϪCH₂group. The ³J(H_α,H_β) coupling constant

for this group (6.1 Hz, Table 1) suggests that it is part of a

five-membered ring: the coupling constant is intermediate

in magnitude between that observed in the four-membered

Figure 2. X-ray structure of bis(ethene) complex 5^ϩ

Cation 5^ϩhas a pseudo square pyramidal geometry with 2-rhodaoxetane ring in 12b^ϩand the six-membered ring in

the amine occupying the apical position, and the N₄Me₂the rhodium 2-(acetimidoyloxy)ethyl complex 13b^2ϩ

ligand in a tridentate coordination mode. Three complexes (Scheme 5).^[5]

in which this coordination mode is found for N₄Me₂(or an

Crystals of 8aBPh₄suitable for X-ray diffraction were ob-

analogous ligand) have been reported earlier,^[9]but usually tained by slow diffusion of diethyl ether into a 1,2-dichloro-

this ligand adopts a tetradentate coordination mode.^[10]In ethane/acetonitrile solution. The unit cell contains two crys-

complex 5^ϩ, as well as in the earlier reported κ³-N₄Me₂tallographically independent units, which are almost mirror

complexes,^[9]the N₄Me₂ligand adopts a syn (chair-boat) images. The structure of one of the units is shown in Fig-

conformation. The X-ray structure of 5^ϩis discussed in ure 3. The five-membered ring has an envelope conforma-

more detail in the supporting information.

tion. The puckering of the 3-rhoda-1,2-dioxolane ring is vir-

Mono-ethene complex 6PF₆is easily obtained by al- tually the same as in the 3-platina-1,2-dioxolane ring of

lowing 5PF₆to stand in acetone solution under a nitrogen 1.^[3a],[^[12]The average O1ϪO2 distance [1.500(17) A] is nor-

˚

[3a]

˚

[13]

atmosphere at room temperature for approximately four mal compared with the OϪO distances in 1 [1.482(15) A]

˚

hours (Scheme 3). This is not a reversible reaction; bubbling and other MϪOϪO-C compounds (1.40Ϫ1.52 A);

the

˚

ethene through a solution of 6PF₆, or exposure of such a average O2ϪC2 distance [1.443(10) A] is also similar to that

solution to an ethene atmosphere does not lead to the in 1 [1.407(19) A] and other MϪOϪO-C compounds

˚

[14]

˚

formation of 5PF₆. The rate and selectivity of the conver- (1.40Ϫ1.47 A).

sion of 5^ϩto 6^ϩare highly dependent on the counterion

The nature of the counterion largely influences the select-

Ϫ

used. Formation of 6^ϩis slower and more selective if PF₆

ivity of this solid-gas oxygenation reaction. On changing

is used as the counterion, instead of BPh₄^Ϫ. Furthermore, the counterion of 7^ϩfrom BPh₄^Ϫto PF₆^Ϫ, a 1:1 mixture of

1074

Eur. J. Inorg. Chem. 2003, 1072Ϫ1087

3-Metalla-1,2-dioxolanes and Their Reactivity

FULL PAPER

Scheme 4. Formation and rearrangement of 3-metalla-1,2-dioxolanes

Table 1. ¹H NMR chemical shifts (ppm) and coupling constants

(Hz) of the RhCH₂CH_nO fragments in CD₃CN

Compound

δ(MCH₂)

δ(CH_nO)^[a]

³J_H,H

²J_H,Rh

8a^؉

2.57(dt)

3.55 (dt)

2.03(t)

3.25(t)

3.41(t)

2.54(t)

2.63(t)

3.66(t)

4.88(t)

9.26(t)

9.98(t)

9.21(t)

10.11(t)

9.57(t)

9.51(t)

9.53(t)

9.46(t)

9.70(t)

6.1

6.2

6.7

6.5

7.5

5.1

4.9

5.2

4.9

5.4

4.9

4.7

4.8

5.5

2.4

Ϫ

8b^؉

10a^؉

10b^؉

16^؉

2.69(t)

Ϫ

2.90(dt)

2.24(dt)

2.69(dd)

3.47(dd)

3.07(d)

3.66(d)

3.14(dd)

3.05(dd)

3.23(dd)

3.39(d)

3.21(dd)

2.5

2.9

Ϫ

12b^؉

9a^؉

9b^؉

Figure 3. X-ray structures of 3-rhoda-1,2-dioxolane 8a^ϩand rhod-

ium formylmethyl hydroxy complex 9a^ϩ

11a^؉

11b^؉

17^؉

Ϫ

3.2

2.7

2.5

Ϫ

20a^2؉

21a^؉

22a^؉

18^؉

8aPF₆and a new complex 8bPF₆is obtained after exposure

1

to air for two days.^[11]The ESI-MS and H NMR spectra

of the mixture of 8aPF₆and 8bPF₆in CD₃CN indicate that

8b^ϩis the isomeric 3-rhoda-1,2-dioxolane in Scheme 4. The

C_αresonances in the ¹³C NMR spectrum are at δ ϭ 35.0

and δ ϭ 44.8 ppm for 8a^ϩand 8b^ϩ, respectively, reflecting

the stronger donor capacity of a pyridine versus an amine

group (Table 2). The same trend is observed for 9a^ϩ/9b^ϩ,

10a^ϩ/10b^ϩ, and 11a^ϩ/11b^ϩ, which are discussed below.

The NOE contacts in 8a^ϩand 8b^ϩare consistent with

their proposed structures: isomer 8a^ϩshows NOE contacts

between RhϪCH₂ϪCH₂Ϫ and one proton each of the two

equivalent RhϪN_amineϪCH₂Ϫ groups, and between

RhϪCH₂ϪCH₂Ϫ and the two equivalent py-H6 atoms; iso-

mer 8b^ϩshows NOE contacts between RhϪCH₂ϪCH₂Ϫ

and all three py-H6 atoms, and between RhϪCH₂ϪCH₂Ϫ

and the two equivalent py-H6 atoms.

2.8

[a]

n ϭ 1,2.

Possibly, the different packing in (microcrystalline) 7BPh₄

and 7PF₆leads to the different accessibility of cation 7^ϩto

O₂. Remarkably, oxidation of 7^ϩby hydrogen peroxide only

leads to the formation of 2-rhodaoxetane 12b^ϩ(N_amine, C

trans) (Scheme 5).^[5]Thus far, a 2-rhodaoxetane, 12a^ϩ

(N_amine, O trans), has not been observed.

Besides the influence of the counterion, small ligand

changes also have a large effect on the reactivity of solid

rhodium-ethene complexes towards air. Substitution of one

Scheme 5. Typical ³J(H_α,H_β) for RhϪCH₂ϪCH₂fragments in four-

membered (12b^ϩ), five-membered (8a^ϩ, 8b^ϩ), and six-membered

(13b^2ϩ) rings

Eur. J. Inorg. Chem. 2003, 1072Ϫ1087

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A. W. Gal et al.

FULL PAPER

Table 2. ¹³C NMR chemical shifts (ppm) and coupling constants

(Hz) of the RhCH₂CH_nO fragments in CD₃CN

10aBPh₄(Scheme 4). Exposure of solid 4PF₆to air results

in the formation of a mixture of the isomeric iridadioxol-

anes 10aPF₆and 10bPF₆, in an approximate ratio of 2:5

(Scheme 4). Powder X-ray diffraction spectra of 4PF₆and

7PF₆show that these complexes are isomorphous, which

indicates that the different ratios in which the isomeric 3-

rhoda- and 3-iridadioxolanes are formed do not stem from

the different packing of the starting materials.

Compound

δ(MCH₂)

δ(CH_nO)^[a]

¹J_C,Rh

8a^؉

35.0(d)

44.8(d)

15.8(s)

23.9(s)

30.3(d)

1.3(d)^[b]

26.9(d)

34.5(d)

16.3(s)

20.7(s)

33.4(d)

27.8(d)

28.1(d)

14.8(s)

70.2(s)

72.8(s)

71.1 or 71.8(s)

71.6(s)

71.7(s)

78.7(d)

209.0(s)

210.8(s)

209.4(s)

211.2(s)

207.7(s)

206.7(d)

210.1(s)

211.1(s)

25.0

28.8

Ϫ

8b^؉

10a^؉

10b^؉

16^؉

Ϫ

25

ESI-MS spectra of 10aBPh₄and 10aPF₆/10bPF₆could

not be obtained because of the instability of these com-

plexes in solution at room temperature (see below). The ¹H

NMR spectra show two triplets for the IrϪCH₂ϪCH₂Ϫ

12b^؉

9a^؉

18.4^[b]

21.0

25.0

Ϫ

9b^؉

11a^؉

11b^؉

17^؉

3

fragment, with J(H_α,H_β) ϭ 6.2 and 6.7 Hz for 10a^ϩand

Ϫ

21.2

20.4

20.7

Ϫ

10b^ϩ, respectively. This indicates that the fragments are part

20a^2؉

21a^؉

22a^؉

1

of five-membered rings (Table 1, Scheme 5). The H NMR

signals for IrCH₂- and for ϪCH₂OϪ were assigned by ana-

logy with the 3-rhoda-1,2-dioxolanes (Table 1).

[a]

[b]

n ϭ 1,2. [D₆]Acetone.

Rhodium N₄Me₂Complexes

Py-H6 of tpa for a methyl group, for example, leads to a

large decrease in the reaction rate. According to the ¹H

NMR spectrum (Scheme 6), exposure of solid 14PF₆to

pure molecular oxygen for 7 months results in approxim-

ately 45% conversion into a 2:1 mixture of 15a^ϩand 15b^ϩ

(the remainder being starting material). Exposure of solid

14BPh₄to pure molecular oxygen for a similar period of

time also results in the formation of a mixture of 15a^ϩand

15b^ϩ. This was unexpected since exposure of the analogous

complex 7BPh₄only results in the formation of isomer 8a^ϩ.

Again, different packing in 7BPh₄and 14BPh₄might be

responsible for this difference in selectivity.

On reaction of solid 6PF₆with dioxygen (instead of air;

see below), at room temperature in the dark, 16PF₆was

formed within a few days.^[11]The H NMR spectrum of

1

16PF₆shows two double triplets at δ ϭ 2.94 ppm and at

δ ϭ 3.70 ppm, indicating the presence of a RhCH₂CH₂X

fragment (Table 1). A coupling constant of J_H,Hϭ 6.5 Hz

for these signals indicates that a five-membered ring is

formed (Table 1). The ESI-MS spectrum shows a base peak

at m/z ϭ 431, which is in accordance with the formation of

3-rhodadioxolane 16^ϩ(Scheme 7). All attempts to obtain

X-ray quality crystals of 16^ϩfailed, partly because of its

instability in solution.

3

Rearrangement of 3-Metalla-1,2-dioxolanes to

Formylmethyl Hydroxy Complexes

Rhodium tpa Complexes

Exposure of microcrystalline 8aBPh₄to glass-filtered

daylight under N₂results in the selective conversion into

the corresponding rhodium formylmethyl hydroxy complex

9aBPh₄, in several weeks (Scheme 4). Similarly, exposure of

a solution of 8aBPh₄in CD₃CN to the glass-filtered light

of a high-pressure mercury lamp at Ϫ30 °C results in the

1

conversion into 9aBPh₄. Monitoring of this reaction by H

NMR indicates that an optimum yield of 90% 9aBPh₄is

obtained after 90 minutes of illumination (see Supporting

Information).

The ESI-MS spectrum of 9a^ϩis similar to that of 8a^ϩ,

with the exception of a peak at m/z ϭ 435, which corre-

sponds to the loss of water from the parent cation. Such

loss of water in the gas-phase has been observed earlier

for the transient formylmethyl hydroxy complex

[(MeCN)(Bzbpa-κ³)Rh(CH₂CHO-κ¹)(OH)]BPh₄(19BPh₄),

Scheme 6. Oxygenation of rhodium ethene complex 14PF₆

Iridium tpa Complexes

Exposure of a solution of 4BPh₄to air leads to a mixture which is the only other formylmethyl hydroxy complex re-

of unidentified products, whereas exposure of solid 4BPh₄ported thus far,^[15,16]although several other formylmethyl

to air leads to the formation of 3-irida-1,2-dioxolane complexes have been reported.^[17]

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Eur. J. Inorg. Chem. 2003, 1072Ϫ1087

3-Metalla-1,2-dioxolanes and Their Reactivity

FULL PAPER

Scheme 7. Formation and rearrangement of rhodadioxolane 16PF₆and subsequent reaction with CO₂

1

The H NMR and ¹³C NMR spectra of 9aBPh₄show

signals typical of a metal-bound formylmethyl group, sim-

ilar to those found in 19BPh₄(Tables 1 and 2).^[16]Complex

9a^ϩshows a strong IR absorption at 1655 cm^Ϫ1, in accord-

ance with the presence of a carbonyl group.

After repeated attempts to obtain X-ray quality crystals

Scheme 8. Proposed mechanisms for rearrangement of 3-metalla-

1,2-dioxolanes: a) photochemically, to a formylmethyl hydroxy

complex b) proton assisted, to a formylmethyl hydroxy complex

of 9aBPh₄had failed, an attempt was made to photochem-

ically convert a single crystal of 8aBPh₄to a single crystal

of 9aBPh₄. The crystal that had been used for the X-ray c) directly, to an oxo complex species and acetaldehyde^[1a,2]and

d) directly, to an oxo complex and ethylene oxide^[1f]

structure determination of 8aBPh₄was exposed to glass-

filtered daylight for one week and its crystal structure was

re-determined. It was found that 8a^ϩhad been fully con- lattice. The mechanism, shown in Scheme 8 (see a), is sup-

verted into 9a^ϩleaving the crystal packing virtually un- ported by preliminary DFT calculations.^[19]

changed (a ‘‘topotactic’’ transformation).^[18]

Analogous to microcrystalline 3-rhoda-1,2-dioxolane

The crystal structure of 9a^ϩshows that the hydroxy 8aBPh₄, the microcrystalline mixture of the isomeric 3-

group forms a hydrogen-bond with the formyl fragment, rhoda-1,2-dioxolanes 8aPF₆and 8bPF₆(8aPF₆/8bPF₆) re-

thus forming a puckered six-membered ring (Figure 3). The arranges photochemically to a mixture of the isomeric for-

bridging hydrogen (H1) was refined at an O1ϪH1 distance mylmethyl hydroxy complexes 9aPF₆and 9bPF₆(9aPF₆/

˚

of 0.80(5) A [RhϪO1ϪH1 ϭ 99(4)°] and a H1ϪO2 distance 9bPF₆; Scheme 4). However, 8aBPh₄and 8aPF₆/8bPF₆re-

of 1.92(5) A [O1ϪH1ϪO2 ϭ 168(5)°]. The puckering of the act differently when exposed to a N₂atmosphere saturated

six-membered ring results from the rotation of the formyl with H₂O; complex 8aBPh₄proved to be stable, whereas

fragment around the C1ϪC2 bond [torsion angle 8aPF₆/8bPF₆rearranges to 9aPF₆/9bPF₆. Since 8aPF₆/

RhϪC1ϪC2ϪO2 ϭ Ϫ72(3)°]. The crystal structure of 9a^ϩ8bPF₆is stable under dry N₂, this reactivity must have been

is discussed in more detail in the supporting information.

triggered by the presence of H₂O. Since there is no obvious

We propose that the photochemical rearrangement of mechanism by which H₂O would directly cause OϪO bond

8a^ϩto 9a^ϩinvolves photolysis of the OϪO bond, followed breaking in the rhodadioxolane, we considered the possibil-

by abstraction of a β-hydrogen atom from ϪCH₂ϪCH₂ϪO^·ity that a trace of acid (possibly generated from hydrolysis

Ϫ

by ϪO^·(Scheme 8, a). In the solid state, the puckering of of a small amount of PF₆to PF₂O₂and HF) catalyzes

the 3-rhoda-1,2-dioxolane ring positions a β-hydrogen in the conversion. To investigate proton-assisted ring opening

close proximity of the O1 atom (Figure 3). Therefore, this in solution, 0.1 equivalent of the noncoordinating acid

reaction would not be hindered by the constraints of the [H(OEt₂)₂]B[C₆H₃(CF₃)₂]₄(HBAr₄^F) was added to a solu-

Eur. J. Inorg. Chem. 2003, 1072Ϫ1087

1077

A. W. Gal et al.

FULL PAPER

1

tion of 8aBPh₄in CD₃CN. In a typical experiment, the H

Formylmethyl hydroxy complexes 9a^ϩand 9b^ϩdecom-

NMR spectrum shows that 8a^ϩis converted into the for- pose to a mixture of unidentified products in solution at

mylmethyl hydroxy complex 8a^ϩ(87%) within 10 minutes, room temperature on prolonged exposure to light.

and a small amount (8%) of the formylmethyl aqua com-

plex 20a^2ϩ(i.e. protonated 9a^ϩ) is also formed.^[20]Likewise,

Iridium tpa Complexes

addition of 1.1 equivalent of HBAr₄^Fto a solution of

Both 10a^ϩand 10b^ϩrearrange to iridium formylmethyl

hydroxy complexes (11a^ϩand 11b^ϩ) on exposure to light.

The ESI-MS spectra of 11aBPh₄and 11aPF₆/11bPF₆show

the expected base peak at m/z ϭ 543. For 11aBPh₄, the

daughter ion spectrum from this base peak shows a peak

at m/z ϭ 525, corresponding to the loss of water.

8aBPh₄results in the formation of 20a^2ϩin approximately

85% yield within 10 minutes.^[20]In the latter case, any 9a^ϩ

formed is apparently directly protonated. This protonation

results in a downfield shift of the RhϪCH₂ϪCHO and

1

RhϪCH₂ϪCHO H NMR signals from δ ϭ 2.69 to δ ϭ

3.05 ppm and from δ ϭ 9.26 to δ ϭ 9.51 ppm, respectively.

The base-peak in the ESI-MS spectrum of the obtained so-

lution has the correct isotope distribution pattern and m/z

value (227) for 20a^2ϩ. As demonstrated by its formylmethyl

¹H NMR signals, a trace of 20a^2ϩis also formed in the

conversion of solid 8aPF₆/8bPF₆to 9aPF₆/9bPF₆under N₂

saturated with H₂O. This supports our hypothesis of an

acid-catalyzed ring opening.

There is a large difference in reactivity between the 3-

rhodadioxolanes and the 3-iridadioxolanes: 3-iridadioxol-

anes rearrange to form formylmethyl hydroxy complexes in

solution at room temperature, whereas 3-rhodadioxolanes

need to be exposed to light or protons before rearrangement

can take place. It is possible that the iridadioxolanes are

more sensitive to traces of adventitious acid, e.g. on glass

surfaces, than the rhodadioxolanes. Another possibility is

that for iridium, water is already a strong enough acid to

induce the conversion. Finally, an alternative conversion

mechanism, not requiring any acid, may be possible for iri-

dium.

The iridium formylmethyl hydroxy complexes 11a^ϩand

11b^ϩare stable in CH₃CN solution at room temperature

when exposed to light, whereas the rhodium analogues de-

compose under these conditions.

A possible mechanism for the acid-catalyzed ring open-

ing is shown in Scheme 8, b. Protonation of 8a^ϩat O_αin-

duces heterolytic splitting of the OϪO bond, followed by

the deprotonation at C_βby an external base and the forma-

tion of a carbonyl double bond. This mechanism was sup-

ported by preliminary DFT calculations.^[19]

Rhodium N₄Me₂Complexes

Both in the presence and absence of visible light, the solid

mono-ethene complex 6PF₆reacts with air, within a few

days at room temperature, to form a mixture of two formyl-

methyl complexes in an approximate ratio of 5:1, according

The isomeric 3-rhodadioxolanes 8a^ϩand 8b^ϩclearly dif-

fer in their photoreactivity: on exposure of a CD₃CN solu-

tion of 8a^ϩand 8b^ϩto glass-filtered daylight at room tem-

1

to the H NMR spectrum in CD₃CN. The ESI-MS spec-

trum of the mixture in CH₃CN shows a base peak at m/z ϭ

431, in accordance with the presence of the formylmethyl

hydroxy complex 17^ϩ, and a peak at m/z ϭ 475, corres-

ponding to the formylmethyl hydrogen carbonate complex

18^ϩ. Water present in the air probably induces an acid-cata-

lyzed rearrangement of the initially formed dioxolane to a

formylmethyl hydroxy complex. Although rearrangement

on exposure to a nitrogen atmosphere saturated with water

had been observed earlier for the tpa complexes (see above),

rearrangement on exposure to air was not observed. Fur-

thermore, the resulting formylmethyl hydroxy complex re-

acts with carbon dioxide from the air, forming 18^ϩ. This

has not been observed for the tpa complexes either. How-

ever, exposure of 9aBPh₄or 11aBPh₄to a CO₂atmosphere

leads to the full conversion into the formylmethyl hydrogen

carbonate complexes 21aBPh₄and 22aBPh₄, respectively

(Scheme 9). On removal of the CO₂atmosphere, CO₂is re-

leased and the formylmethyl hydroxy complexes 9aBPh₄or

11aBPh₄are regenerated. Formation of rhodium and iri-

dium hydrogen carbonate complexes from metal hydroxy

complexes and CO₂, and vice versa have been reported be-

fore.^[21]

1

perature, the relative intensities of the H NMR 2-peroxy-

ethyl signals show that the initial reaction rate of 8b^ϩis three

times faster than that of 8a^ϩ(Figure 4).

Figure 4. Relative intensities of the 2-peroxyethyl ¹H NMR signals

of 8a^ϩ(᭿) and 8b^ϩ(᭡) on exposure to glass-filtered daylight

1078

Eur. J. Inorg. Chem. 2003, 1072Ϫ1087

3-Metalla-1,2-dioxolanes and Their Reactivity

FULL PAPER

24BPh₄with water (see below), and subsequently with CO₂

occur. The ¹H NMR and ¹³C NMR spectra of 24BPh₄only

show signals for the (coordinated) tpa ligand. The ESI-MS

spectrum of 24BPh₄shows a base peak at m/z ϭ 425, cor-

responding to [(tpa)Rh ϩ O₂]^ϩ, and the loss of O₂from the

parent cation.^[22]

Exposure of complex 24BPh₄to a nitrogen atmosphere

saturated with water leads to the complete conversion into

25BPh₄. The H NMR and ¹³C NMR spectra of 25BPh₄

1

Scheme 9. Reversible reaction of formylmethyl hydroxy complexes

again only show signals for the (coordinated) tpa ligand.

The ESI-MS spectrum shows a base peak at m/z ϭ 443,

corresponding to 25^ϩ, and the loss of H₂O, HO₂, and H₂O₃

from the parent cation. Complex 25BPh₄is the first rhod-

ium hydroperoxy hydroxy complex reported, but other

metal hydroperoxy hydroxy complexes have been reported

earlier.^[23]Analytically pure samples of 24BPh₄and 25BPh₄

were not obtained, due to their instability in solution at

room temperature. Since the decomposition of 25BPh₄is a

problem in solution at Ϫ30 °C as well, no ¹³C NMR spec-

troscopic data were obtained for this complex.

9a^ϩand 11a^ϩwith CO₂

Exposure of solid 16PF₆(obtained from 6PF₆and dioxy-

gen; see above) to visible light and N₂leads to the conver-

1

sion into 17PF₆, as shown by the ESI-MS, H NMR and

¹³C NMR spectra in CD₃CN (Tables 1 and 2). Exposure of

16PF₆to water vapour/N₂also leads to the formation of

Ϫ

17PF₆, probably due to the PF₆counterion (see above).

Oxidation of a Rhodium Propene Complex to a Peroxo

Complex and Its Reactivity towards Water

As mentioned earlier, exposure of solid 7BPh₄to air not

only produces 3-rhoda-1,2-dioxolane 8aBPh₄, but also a

small amount of the hydroperoxy hydroxy complex 25BPh₄.

Conclusions

We have achieved selective oxidation of [M]^I(ethene)

Exposure of solid 7BPh₄to pure dioxygen, however, leads (M ϭ Rh, Ir) complexes by air or dioxygen to form isolable

to the formation of 8aBPh₄and a small amount of the per- 3-metalla-1,2-dioxolanes for the first time. Remarkably se-

oxo complex 24BPh₄. This peroxo complex can be obtained lective dioxygenation was only achieved for ethene com-

more efficiently by the oxidation of solid [(tpa)Rh- plexes embedded in a crystalline matrix. The reasons for

(CH₂CHCH₃)]BPh₄(23BPh₄) with molecular oxygen this difference between solid phase reactivity and solution

(Scheme 10).

phase reactivity have not yet been elucidated. However, our

Complex 23BPh₄was synthesized from [{(ethene)₂- results clearly indicate that solid-gas reactions should be

RhCl}₂], propene, tpa, and NaBPh₄. It is the first reported considered as a useful alternative to conventional solution

rhodium propene complex stabilized by a tetradentate ni- phase chemistry, not only under heterogeneous conditions

trogen donor ligand. Propene coordinates less strongly to (high pressures and temperatures), but also at room temper-

the rhodium center than ethene, resulting in an easier loss ature and atmospheric pressure.

of olefin from the complex and the quantitative formation

Small changes have a large effect on the reactivity of the

of 24BPh₄on oxidation with molecular oxygen. Oxidation ethene complexes. The dioxygenation of 14PF₆is much

with air results in a mixture of unidentified products. The slower than of 7PF₆. Using a completely different N₄-ligand

reason for this is still unclear. Possibly, further reactions of (N₄Me₂) results in a higher reactivity of not only the ethene

Scheme 10. Reaction of propene complex 23BPh₄with dioxygen

Eur. J. Inorg. Chem. 2003, 1072Ϫ1087

1079

A. W. Gal et al.

FULL PAPER

complex, but also of the 3-rhodadioxolane and the formyl- Experimental Section

methyl hydroxy complex. More interestingly, even the coun-

General Methods: All procedures were performed under a nitrogen

atmosphere using standard Schlenk techniques, unless indicated

otherwise. The solvents (p.a.) were deoxygenated by bubbling

through a stream of nitrogen.

terion affects the oxidation chemistry; oxygenation of 7PF₆

results in the formation of two isomeric 3-rhodadioxolanes,

whereas oxygenation of 7BPh₄only yields one isomer. Thus,

it appears that for these solid-gas reactions, new opportun-

ities for reaction tuning exist.

The observed rearrangement of 3-metalla-1,2-dioxolanes

to formylmethyl hydroxy complexes is in marked contrast

with the rearrangements proposed earlier for 3-metalla-1,2-

dioxolanes i.e. direct rearrangement to a metal oxo complex

and acetaldehyde, or to a metal oxo complex and ethylene

oxide.^[1f]However, the formylmethyl complexes may still be

intermediates in the formation of acetaldehyde and a rhod-

ium oxo or hydroxy complex.

In the 1980’s Read et al. proposed that 3-rhodadioxolanes

are intermediates in the co-oxygenation of terminal or cyc-

lic olefins and triphenylphosphane, to ketones and triphen-

ylphosphane oxide (Scheme 11).^[1b]The 3-rhodadioxolane

is converted into a 2-rhodaoxetane via the transfer of an O

atom to triphenylphosphane. The triphenylphosphane oxide

stabilized 2-rhodaoxetane then successively loses triphenyl-

phosphane oxide and a ketone. Our findings do not support

such a mechanism. 3-Rhoda-1,2-dioxolane 8aBPh₄does not

react with triphenylphosphane, and the formation of 2-rho-

daoxetanes from 3-rhoda-1,2-dioxolanes have not been ob-

served.

NMR experiments were carried out on Bruker DPX200, Bruker

AC300, Bruker WM400, and Bruker AM-500. Solvent shift refer-

ences for ¹H NMR are: CD₂Cl₂δ(¹H) ϭ 5.31 ppm, CD₃CN

δ(¹H) ϭ 1.94 ppm and [D₆]acetone δ(¹H) ϭ 2.05 ppm. Solvent shift

references for ¹³C NMR are: CD₃CN δ(¹³C) ϭ 118.1 ppm and

[D₆]acetone δ(¹³C) ϭ 206.18 ppm. Abbreviations used are: s ϭ

singlet, d ϭ doublet, dd ϭ double doublet, t ϭ triplet, dt ϭ double

triplet, q ϭ quadruplet, qq ϭ quadruplet of quadruplets, m ϭ mul-

tiplet, dm ϭ double multiplet, br. ϭ broad. Mass spectra (ESI)

were recorded on a Finnigan MAT 900S and a Finnigan TSQ 7000

mass spectrometer. Elemental analyses (C, H N) were carried out

on an Hanau Elementar-Analyzer CHN-O-Rapid. Infrared spectra

were measured on a PerkinϪElmer 1720X spectrometer.

Compounds [{(CH₂CH₂)₂RhCl}₂],^[24]tpa,^[25]Metpa,^[26][(Me-

tpa)Rh(CH₂CH₂)]BPh₄/PF₆,^[5]

[(tpa)Rh(CH₂CH₂)]BPh₄/PF₆,^[5]

N₄Me₂,^[27][{(C₈H₁₄)IrCl}₂],^[28]and [H(OEt₂)₂]B[C₆H₃(CF₃)₂]₄

(HBAr^F₄)^[29]were prepared according to literature procedures. All

other chemicals were obtained commercially and were used without

further purification.

X-ray Diffraction: Crystals of 3PF₆suitable for X-ray diffraction

were obtained by slow diffusion of diethyl ether into an acetonitrile

solution. Crystals of 5PF₆were obtained by crystallization from

acetone/diethyl ether (v/v ϭ 1:3) over a period of nine days at Ϫ70

°C. Crystals of 8aBPh₄were obtained through slow diffusion of

diethyl ether into a 1,2-dichloroethane/acetonitrile solution. A crys-

tal of 9aBPh₄was obtained by exposure of a crystal of 8aBPh₄to

glass-filtered daylight for one week.

X-ray diffraction data for 3PF₆and 5PF₆were collected at 208(2)

K on an EnrafϪNonius CAD4 diffractometer, using graphite mon-

˚

ochromatized Mo-K_αradiation (λ ϭ 0.71073 A) and Cu-Kα radi-

˚

ation (λ ϭ 1.54184 A), respectively. X-ray diffraction data for

8aBPh₄and 9aBPh₄were collected at 150(2) K on a Nonius

KappaCCD diffractometer with rotating anode, using graphite

˚

monochromatized Mo-K_αradiation (λ ϭ 0.71073 A). The struc-

tures were solved by the PATTY^[30]option of the DIRDIF^[31]pro-

gram system. All non-hydrogen atoms were refined with aniso-

tropic temperature factors. The bridging hydrogen atom of the for-

myl fragment in 9aBPh₄was taken from a difference Fourier map

and was freely refined. All other hydrogen atoms were placed at

calculated positions and were refined isotropically in riding mode.

Subsequently, for 5PF₆, the hydrogen atoms were freely refined.

Selected bond lengths and angles are shown in Tables 3 and 4.

Other relevant crystal data are summarized in Table 5. Drawings

were generated with the program PLATON.^[32]

Scheme 11. Mechanism proposed by Read for rhodium catalyzed

co-oxygenation of olefins and triphenylphosphane to ketones and

triphenylphosphane oxide^[1b]

Both Mimoun and Read proposed the formation of 3-

rhoda-1,2-dioxolanes from rhodium peroxo ethene com-

plexes.^[1a,1b]We have not observed such peroxo ethene inter-

mediates in the formation of 3-rhoda-1,2-dioxolanes. Our

group has isolated iridium peroxo ethene complexes, gener-

ated through the reaction of iridium ethene complexes with

dioxygen in solution, however, these complexes are quite

stable and the formation of 3-irida-1,2-dioxolanes is not ob-

served from these complexes.^[6c]

3PF₆: Geometrical calculations (PLATON, Spek 1995)^[33]revealed

neither unusual geometric features, nor unusual short intermolecu-

lar contacts. The calculations revealed no higher symmetry and no

solvent accessible areas.

5PF₆: There is a disordered solvent molecule present in the crystal

structure. Calculations (PLATON, Spek,1995)^[33]showed a void of

3

˚

95 A , containing 31 electrons, at 0.0032, 0.466, 0.842. Based on

the synthetic route, the electron density most probably represents

one acetone molecule (C₃H₆O, 32 electrons). The SQUEEZE pro-

1080

Eur. J. Inorg. Chem. 2003, 1072Ϫ1087

3-Metalla-1,2-dioxolanes and Their Reactivity

FULL PAPER

3

˚

ϩ

˚

y, 1/4; y ϭ Ϫ0.036), and one of 152 A , containing 44 electrons,

around an inversion center (position 4b: 1/2, 0, 0). Based on the

synthetic route and evidence from NMR spectroscopy, it is as-

sumed that these electron densities represent one molecule of di-

ethyl ether (C₄H₁₀O, 42 electrons) plus one molecule of acetonitrile

Table 3. Selected bond lengths [A] for 3 , 5 , 8aA , 8aB , and

9a^ϩ(M ϭ Rh or Ir)

3^ϩ

5^ϩ

8aA^؉

8aB^ϩ

9a^ϩ

3

˚

N1ϪM

N2ϪM

N3ϪM

N4ϪM

C1ϪM

C2ϪM

C3ϪM

C4ϪM

O1ϪM

O1ϪO2

O1ϪH1

H1ϪO2

O2ϪC2

C2ϪC1

C3ϪC4

2.175(8)

2.027(10)

Ϫ

2.311(5)

2.145(5)

2.163(5)

Ϫ

2.054(2)

2.015(3)

2.133(3)

2.030(3)

2.030(16)

Ϫ

2.054(2)

2.015(3)

2.133(3)

2.030(3)

2.076(16)

Ϫ

2.040(3)

2.018(4)

2.102(3)

2.033(4)

2.085(4)

Ϫ

(CH₃CN, 22 electrons) in the first void (64 electrons, 28.5 A /atom),

and one molecule of dichloroethane (C₂H₄Cl₂, 50 electrons) in the

3

˚

second void (30.2 A /atom). It was not possible to assign any phys-

ically meaningful parameters to the electron densities found in the

difference fourier map. Therefore the SQUEEZE procedure was ap-

plied to account for these electron densities.

2.056(8)

2.164(11)

2.126(13)

2.157(11)

2.118(10)

Ϫ

2.113(7)

2.143(7)

2.104(8)

2.125(8)

Ϫ

9aBPh₄: Hydrogen atom H1 was clearly visually observed in a dif-

ference fourier map and its position was subsequently determined

automatically. Its positional and thermal parameters were refined

freely and this refinement proved to be stable. The position of H1

is well outside the regions influenced by the SQUEEZE procedure

described later on.

2.01(2)

1.504(18)

Ϫ

1.97(2)

1.496(16)

Ϫ

2.014(3)

Ϫ

0.80(5)

1.92(5)

1.103(11)

1.245(12)

Ϫ

1.430(11)

1.563(11)

Ϫ

1.455(9)

1.534(11)

Ϫ

1.419(16)

1.416(16)

1.411(11)

1.341(11)

From the anisotropic thermal displacement parameters for C2 and

O2 it is clear that these atoms show a large positional disorder.

Although it is possible to use several partially occupied positions

for these atoms, no physically reasonable models result from these

parameters, at least not any better than the model presented here.

Splitting up these atoms serves no other purpose but to lower the

R-value. The calculated hydrogen positions on C2 are therefore

merely indications of possible positions.

Table 4. Selected angles and torsion angles [°] for 3^ϩ, 5^ϩ, 8aA^؉,

8aB^ϩ, and 9a^ϩ(M ϭ Rh or Ir)

3^ϩ

82.2(3)

5^ϩ

78.41(19)

78.2(2)

Ϫ

8aA^؉

8aB^ϩ

9a^ϩ

N1ϪMϪN2

N1ϪMϪN3

N1ϪMϪN4

N2ϪMϪN3

N2ϪMϪN4

N3ϪMϪN4

C1ϪMϪO1

C2ϪC1ϪM

O2ϪC2ϪC1

O1ϪO2ϪC2

MϪO1ϪO2

C1ϪMϪN1

C1ϪMϪN2

C1ϪMϪN3

C1ϪMϪN4

O1ϪMϪN1

O1ϪMϪN2

O1ϪMϪN3

O1ϪMϪN4

MϪO1ϪH1

O1ϪH1ϪO2

MϪC1ϪC2Ϫ

O2

84.04(10)

81.87(10)

82.91(10)

88.47(10)

84.04(10)

81.87(10)

82.91(10)

88.47(10)

83.54(13)

Calculations (PLATON, Spek 1995)^[33]showed two distinct voids,

Ϫ

82.83(12)

82.44(13)

87.78(13)

3

˚

one of 239 A , containing 58 electrons, around a two-fold axis (po-

82.1(3)

Ϫ

3

˚

sition 4e, 0, y, 1/4; y ϭ Ϫ0.041), and one of 152 A , containing 39

electrons, around an inversion center (position 4b: 1/2, 0, 0). Based

on the synthetic route and evidence from NMR spectroscopy, it is

assumed that these electron densities possibly represent one molec-

ule of diethyl ether (C₄H₁₀O, 42 electrons) plus one molecule of

acetonitrile (CH₃CN, 22 electrons) in the first void (64 electrons,

77.72(19)

Ϫ

164.1(4)

Ϫ

166.33(10) 166.33(10) 165.46(13)

Ϫ

93.70(10)

84.6(4)

106.0(9)

106.2(18)

106.1(15)

106.3(10)

99.3(3)

91.2(4)

178.7(3)

86.9(4)

175.9(4)

97.0(12)

94.2(3)

96.3(12)

Ϫ

93.70(10)

84.7(4)

102.2(8)

111.5(10)

101.7(11)

110.8(12)

95.9(3)

87.5(4)

175.6(4)

89.8(4)

179.1(7)

95.3(11)

97.5(3)

97.7(11)

Ϫ

94.27(13)

90.18(18)

111.4(5)

146(2)

Ϫ

69.2(6)

Ϫ

71.8(4)

Ϫ

3

Ϫ

˚

29.9 A /non-hydrogen atom), and one molecule of dichloroethane

Ϫ

3

˚

(C₂H₄Cl₂, 50 electrons) in the second void (38.0 A /non-hydrogen

atom). These assumptions are in accordance with the earlier crystal

structure determination of the original crystal of 8aBPh₄before its

exposure to glass-filtered daylight, and account for the calculated

physical molecular properties as reported in this paper.

95.7(4)

89.4(4)

Ϫ

95.3(3)

96.7(3)

172.1(3)

96.18(15)

89.26(16)

176.97(16)

88.44(17)

173.63(15)

96.19(15)

90.80(15)

98.17(15)

99(4)

90.1(4)

Ϫ

It was not possible to assign any physically meaningful parameters

to the electron densities found in the difference fourier map. There-

fore, the SQUEEZE procedure was applied to account for these

electron densities.

Ϫ

168(5)

Ϫ72(3)

Ϫ

CCDC-187013 (3PF₆), CCDC-187012 (5PF₆), CCDC-157414

(8aBPh₄), and CCDC-170096 (9aBPh₄) contain 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 CB2 1EZ, UK; Fax: (internat.) ϩ44Ϫ1223/336-

033; E-mail: deposit@ccdc.cam.ac.uk].

C1ϪMϪC3

C2ϪMϪC4

C1ϪC2ϪM

C3ϪC4ϪM

C4ϪC3ϪM

Ϫ

89.9(4)

84.4(4)

69.5(4)

70.7(5)

72.3(5)

Ϫ

72.1(7)

72.1(6)

69.2(6)

cedure was applied to account for the electron density of the sol-

vent molecule.

Synthesis

Bis(ethene)[N-(2-pyridylmethyl)-N,N-bis(2-pyridylmethyl-

8aBPh₄: The five-membered dioxolane ring has the envelope form

and occurs in two conformations. As expected there is considerable

positional overlap for some of the atoms (C1A and C1B, C2A and

C2B, O1A and O1B). Therefore, some geometrical constraints had

to be applied: the two conformations were ‘SAMEd’ and the aniso-

κN)amine-κN]iridium(I) Hexafluorophosphate (3PF₆): Ethene was

bubbled through a solution of [(C₈H₁₄)₂IrCl]₂(325 mg, 0.36 mmol)

in MeOH (13 mL) until a clear solution was obtained. Under an

ethene atmosphere, tpa (216 mg, 0.74 mmol) was added and the

reaction mixture was stirred for 10 minutes. KPF₆(167 mg,

tropic thermal displacement parameters were tied. Calculations 0.91 mmol) was then added under an ethene atmosphere, and after

(PLATON, Spek 1995)^[33]showed two distinct voids, one of 229 stirring for 1 hour, the solution was cooled to Ϫ78 °C. The cold

3

˚

A , containing 68 electrons, around a two-fold axis (position 4e, 0,

suspension was filtered under a nitrogen atmosphere and the white

1081

Eur. J. Inorg. Chem. 2003, 1072Ϫ1087

A. W. Gal et al.

FULL PAPER

Table 5. Crystallographic data

3^؉

5^؉

8a^؉

9a^؉

Empirical formula

Crystal color

Crystal shape

Crystal size [mm]

Molecular weight

T [K]

C₂₂H₂₆F₆IrN₄P

C₄₇H₅₄BN₄ORh

C₄₈H_50.50BClN_4.50O_2.50Rh C₄₈H_50.50BClN_4.50O_2.50Rh

Light yellow transparent Transparent yellow-brown Transparent yellow

Transparent yellow

Irregular fragment

0.29 ϫ 0.22 ϫ 0.13

879.60

Regular platelet

0.53 ϫ 0.46 ϫ 0.10

683.64

208(2)

Monoclinic

P 21/c

Irregular fragment

0.36 ϫ 0.24 ϫ 0.10

804.66

208(2)

Monoclinic

P 21/n

Irregular fragment

0.29 ϫ 0.22 ϫ 0.13

879.60

150(2)

Crystal system

Space group

Monoclinic

C 2/c

Monoclinic

C 2/c

Unit cell dim. from N refl. 23

21

11.555(2)

17.523(5)

19.686(5)

90

97.38(2)

90

3952.9(17)

1.352

4

17718

14986

˚

a [A]

7.538(2)

14.831(3)

20.753(10)

35.8688(5)

10.7328(2)

24.2609(4)

90

116.6660(10)

90

8346.4(2)

1.400

8

36.0362(2)

10.77600(10)

24.2975(2)

90

116.3883(4)

90

8452.21(11)

1.382

8

˚

b [A]

˚

c [A]

α [°]

β [°]

γ [°]

90

90.07(3)

90

2320.2(13)

1.957

4

3

˚

V [A ]

ρ_calcd.[g·cm^Ϫ3

Z

]

Diffractometer

EnrafϪNonius CAD4

Nonius Kappa CCD

with rotating anode

0.520

Area detector,

and ω scan

Mo-K_α

Nonius Kappa CCD

with rotating anode

0.514

Area detector,

and ω scan

Mo-K_α

Abs. Coefficient [mm^Ϫ1

Scan

]

5.890

ω-2θ

3.805

ω-2θ

Radiation (graphite mon.) Mo-K_α

Cu-Kα

1.54184

1688

˚

Wavelength [A]

F(000)

0.71073

1328

0.71073

3656

0.71073

3656

Θ range [°]

2.70Ϫ27.48

Ϫ9 Յ h Յ 0

Ϫ19 Յ k Յ 0

Ϫ26 Յ l Յ 26

Semi-empir. Ψ-scan^[a]

3.39Ϫ69.93

0 Յ h Յ 14

0 Յ k Յ 21

Ϫ23 Յ l Յ 23

Semi-empir. Ψ-scan^[a]

1.083, 0.947

7865

1.27Ϫ27.48

Ϫ46 Յ h Յ 46

Ϫ13 Յ k Յ 13

Ϫ31 Յ l Յ 31

None

Ϫ

17718

1.73Ϫ25.35

Ϫ43 Յ h Յ 43

Ϫ12 Յ k Յ 12

Ϫ29 Յ l Յ 29

None

Ϫ

14986

Index ranges

Abs. Corr.

Range of rel. transm. fac. 4.786, 0.696

Measured reflections

Unique reflections

5707

5314

7478

9548

7719

[R_int

]

[0.0481]

4542

[0.0633]

4765

[0.0508]

5801

[0.0294]

5510

Observed reflections

[I₀Ͼ 2σ(I₀)]

Data/restraints/parameters 5314/0/308

7478/0/485

1.004

0.0970, 0.0000

9548/184/506

0.963

0.0586, 0.0000

7719/0/473

1.054

0.0870, 6.0419

Goodness-of-fit on F²

SHELXL-97 weight

parameters

1.090

0.1169, 42.6696

Final R1, wR2 [I Ͼ 2σ(I)] 0.0657, 0.1843

0.0702, 0.1617

0.1140, 0.1815

1.635, Ϫ1.208

0.0459, 0.1080

0.0904, 0.1186

0.770, Ϫ0.508

0.0494, 0.1402

0.0721, 0.1492

0.899, Ϫ0.643

R1, wR2 [all data]

0.0766, 0.1992

Diff. Peak and hole [e·A^Ϫ3] 6.907, Ϫ3.638

˚

[a]

A. C. T. North, D. C. Philips, F. S. Mathews, Acta Crystallogr. 1968, A24, 351Ϫ359.

residue was washed with MeOH (3 ϫ 1 mL) and dried in vacuo.

Complex 3PF₆was obtained as a white powder. Yield: 290 mg

(58%). ¹H NMR (200 MHz, CD₂Cl₂, 300 K): δ ϭ 8.69 (ddd,

for 3PF₆(C₂₂H₂₆F₆IrN₄P; 683.66): calcd. C 38.65, H 3.83, N 8.20;

found C 38.78, H 3.90, N 8.36 %.

Bis(ethene)[N-(2-pyridylmethyl)-N,N-bis(2-pyridylmethyl-

4

5

³J_H,Hϭ 4.9, J_H,Hϭ 1.8, J_H,Hϭ 0.9 Hz, 1 H, Py_a-H6), 7.80 (dt,

κN)amine-κN]iridium(

I)

Tetraphenylborate (3BPh₄): Complex

4

3

³J_H,Hϭ 7.7, J_H,Hϭ 1.9 Hz, 1 H, Py_a-H4), 7.73 (dt, J_H,Hϭ 7.8,

3BPh₄was obtained by the same procedure as 3PF₆, using NaBPh₄

instead of KPF₆.

⁴J_H,Hϭ 1.6 Hz, 2 H, Py_b-H4), 7.60 (d, J_H,Hϭ 4.9 Hz, 2 H, Py_b-

H6), 7.37 (m, 3 H, Py-H3), 7.14 (t, J_H,Hϭ 7.0 Hz, 3 H, Py-H5),

3

2

(Ethene)[N,N,N-tris(2-pyridylmethyl-κN)amine-κN]-

iridium(I) Hexafluorophosphate (4PF₆): Complex 4PF₆was synthe-

sized according to the same procedure as bis(ethene) complex 3PF₆,

but nitrogen was bubbled through the MeOH solution before the

addition of KPF₆. Complex 4PF₆was obtained as a yellow/orange

powder. Yield: 83%. ¹H NMR (200 MHz, CD₃CN, 300 K): δ ϭ

5.50 (d[AB], J_H,Hϭ 15.4 Hz, 2 H, NCH₂Py_b), 4.65 (d[AB],

²J_H,Hϭ 15.6 Hz, 2 H, NCH₂Py_b), 4.39 (s, 2 H, NCH₂Py_a), 3.36

(br.t, ³J_H,Hϭ 9.4 Hz, 2 H, CH₂CH₂), 3.22 (t, ³J_H,Hϭ 9.7 Hz, 2 H,

3

CH₂CH₂), 1.94 (t, J_H,Hϭ 9.8 Hz, 2 H, CH₂CH₂), 1.85 (br.t,

³J_H,Hϭ 9.7 Hz, 2 H, CH₂CH₂) ppm; ¹³C{¹H} NMR (125 MHz,

CD₃CN, 243 K): δ ϭ 166.2 (Py_b-C2), 154.6 (Py_a-C2), 150.8 (Py_a-

C6), 150.4 (Py_b-C6), 138.8(Py_b-C4), 138.2 (Py_a-C4), 127.2 (Py_a-C3/

5), 126.6 (Py_b-C3/5), 124.8 (Py_b-C3/5), 124.5 (Py_a-C3/5), 65.4

(NCH₂Py_b), 65.3 (NCH₂Py_a), 39.8 (br., CH₂CH₂), 37.3 (br.,

CH₂CH₂), 34.8 (CH₂CH₂), 30.3 (CH₂CH₂) ppm; elemental analysis

3

9.19 (d, J_H,Hϭ 5.2 Hz, 1 H, Py_a-H6), 8.28 (d, J_H,Hϭ 5.3 Hz, 2

3

H, Py_b-H6), 7.64 (t, J_H,Hϭ 7.8 Hz, 3 H, Py-H4), 7.21 (m, 4 H,

3

Py-H3 and Py_a-H5), 7.05 (t, J_H,Hϭ 6.6 Hz, 2 H, Py_b-H5), 5.11

2

(d[AB], J_H,Hϭ 15.3 Hz, 2 H, NCH₂Py_b), 4.83 (d[AB], J_H,H

ϭ

1082

Eur. J. Inorg. Chem. 2003, 1072Ϫ1087

3-Metalla-1,2-dioxolanes and Their Reactivity

FULL PAPER

15.3 Hz, 2 H, NCH₂Py_b), 4.69 (s, 2 H, NCH₂Py_a), 1.28 (m, 4 H,

7BPh₄was ground with a mortar and exposed to air at room tem-

CH₂CH₂) ppm; ¹³C{¹H} NMR (75 MHz, CD₃CN, 300 K): δ ϭ perature and was left in the dark for 2 days at atmospheric pres-

165.5 (Py_b-C2), 161.1 (Py_a-C2), 152.4 (Py_a-C6), 151.4 (Py_b-C6),

sure.^[11]8aBPh₄was obtained in Ͼ 90% yield, as determined by ¹H

137.8 (Py_a-C4), 136.3 (Py_b-C4), 125.8 (Py_b-C3/5), 124.6 (Py_a-C3/5), NMR spectroscopy. Crystals obtained from a 1,2-dichloroethane

123.4 (Py_b-C3/5), 122.3 (Py_a-C3/5), 71.6 (NCH₂Py_b), 65.9 solution proved to be unsuitable for X-ray diffraction. However,

(NCH₂Py_a), 4.3 (CH₂CH₂), 4.1 (CH₂CH₂) ppm. ESI-MS (THF):

the crystals obtained were used for elemental analysis. Both ¹H

NMR spectroscopy and elemental analysis of these crystals showed

511 [M Ϫ PF₆]^ϩ, 483 [M Ϫ CH₂CH₂Ϫ PF₆]^ϩ; elemental analysis

for 4PF₆(C₂₀H₂₂F₆IrN₄P; 655.61): calcd. C 36.64, H 3.38, N 8.55; that they contained 1.5 molecules of 1,2-dichloroethane per cation.

found C 36.63, H 3.44, N 8.66 %.

¹H NMR (300 MHz, CD₃CN, 297 K): δ ϭ 8.75 (d, ³J_H,Hϭ 5.4 Hz,

3

1 H, Py_a-H6), 8.66 (d, J_H,Hϭ 5.5 Hz, 2 H, Py_b-H6), 7.81 (dt,

(Ethene)[N, N, N-tris(2-pyridylmethyl-κN)amine-κN]-

iridium(I) Tetraphenylborate (4BPh₄): Complex 4BPh₄was obtained

by the same procedure as 4PF₆, using NaBPh₄instead of KPF₆.

4

3

³J_H,Hϭ 7.8, J_H,Hϭ 1.7 Hz, 2 H, Py_b-H4), 7.69 (dt, J_H,Hϭ 7.8,

⁴J_H,Hϭ 1.7 Hz, 1 H, Py_a-H4), 7.40 (d, J_H,Hϭ 8.0 Hz, 2 H, Py_b-

3

H3), 7.35 (m, 3 H, Py_a-H5 and Py_b-H5), 7.28 (m, 8 H, BAr-H2),

3

4

Bis(ethene){3,11-dimethyl-3,11,17,18-tetraazatricyclo-

7.16 (dt, J_H,Hϭ 7.8, J_H,Hϭ 0.9 Hz, 1 H, Py_a-H3), 6.99 (t,

[11.3.1.1^5,9]octadeca-1(17),5(18),6,8,13,15-hexaene-κ⁴N¹,N²,N³}

³J_H,Hϭ 7.4 Hz, 8 H, BAr-H3), 6.84 (t, J_H,Hϭ 7.3 Hz, 4 H, BAr-

3

2

rhodium(

I)

Hexafluorophosphate (5PF₆): [Rh(µ-Cl)(C₂H₄)₂]₂

H4), 4.88 (d[AB], J_H,Hϭ 15.6 Hz, 2 H, NCH₂Py_b), 4.71 (d[AB],

²J_H,Hϭ 15.1 Hz, 2 H, NCH₂Py_b), 4.57 (s, 2 H, NCH₂Py_a), 3.25 (t,

(100 mg, 0.26 mmol) was added to a suspension of NaHCO₃

(100 mg, 1.2 mmol) in methanol (5 mL) at Ϫ20 °C. The reaction

mixture was stirred for 15 minutes, after which N₄Me₂(138 mg,

0.51 mmol) was added. After stirring for 5 minutes at Ϫ20 °C, the

reaction mixture was cooled to Ϫ78 °C and stirred for 30 minutes.

Undissolved material was removed by filtration. A solution of

KPF₆(100 mg, 0.54 mmol) in methanol (1 mL) was then added to

the filtrate at Ϫ78 °C, causing the precipitation of a light yellow

solid. After stirring for 1 hour, the solid was collected by filtration.

Additional KPF₆(60 mg, 0.33 mmol) was added to the filtrate. The

solution was warmed to room temperature for two minutes, after

which it was cooled to Ϫ78 °C again. This produced a second batch

of solid, which was collected by filtration after stirring for 15 mi-

nutes. The combined solids were washed with methanol and dried

under vacuum. Yield: 245 mg (83%). ¹H NMR (500 MHz, [D₆]ace-

³J_H,Hϭ 6.1 Hz, 2 H, RhCH₂CH₂OO), 2.57 (dt, J_H,Hϭ 6.1,

3

²J_H,Rhϭ 2.4 Hz, 2 H, RhCH₂CH₂OO) ppm; ¹³C{¹H} NMR

1

(75 MHz, CD₃CN, 297 K): δ ϭ 164.6 (q, J_C,Bϭ 49.5 Hz, BAr-

C1), 162.7 (Py_b-C2), 158.6 (Py_a-C2), 150.1 (Py_b-C6), 149.5 (Py_a-

C6), 139.4 (Py_a-C4), 139.3 (Py_b-C4), 136.5 (BAr-C2), 126.4 (q,

³J_C,Bϭ 2.8 Hz, BAr-C3), 125.5 (Py_b-C3), 125.4 (Py_a-C3), 124.2

(Py_b-C5), 122.6 (BAr-C4), 121.9 (Py_a-C5), 72.9 (NCH₂Py_a), 70.2

1

(N-CH₂-Py_band RhCH₂CH₂OO), 35.0 (d, J_C,Rhϭ 25.0 Hz,

RhCH₂CH₂OO) ppm. ESI-MS (CD₃CN): 453 [M Ϫ BPh₄]^ϩ, 425

[M Ϫ CH₂CH₂Ϫ BPh₄]^ϩ, 409 [M Ϫ C₂H₄O Ϫ BPh₄]^ϩ, 393 [M Ϫ

C₂H₄O₂Ϫ BPh₄]^ϩ, 391 [M Ϫ C₂H₄O₂Ϫ H₂Ϫ BPh₄]^ϩ; elemental

analysis for 8aBPh₄·1¹/₂C₂H₄Cl₂(C₄₇H₄₈BCl₃N₄O₂Rh; 921.00):

calcd. C 61.36, H 5.26, N 6.09; found C 61.36, H 5.44, N 6.17 %.

(2-Peroxyethyl-κ²C¹,O²)[N,N,N-tris(2-pyridylmethyl-κN)-

amine-κN]rhodium(III) Hexafluorophosphate (8aPF₆/8bPF₆): Com-

plex 7PF₆was ground with a mortar and exposed to air at room

temperature and was left in the dark for 2 days at atmospheric

pressure.^[11]A mixture of 8aPF₆and 8bPF₆in an approximate ratio

of 1:1 was obtained in Ͼ 90% yield, as determined by ¹H NMR

3

tone, 203 K): δ ϭ 7.73 (t, J_H,Hϭ 7.8 Hz, 2 H, Py-H4), 7.37 (d,

³J_H,Hϭ 7.5 Hz, 2 H, Py-H3/5), 7.28 (d, J_H,Hϭ 7.8 Hz, 2 H, Py-

3

2

H3/5), 6.06 (d[AB], J_H,Hϭ 14.1 Hz, 2 H, NCH₂Py), 5.17 (d[AB],

²J_H,Hϭ 16.7 Hz, 2 H, NCH₂Py), 4.51 (d[AB], J_H,Hϭ 16.9 Hz, 2

2

H, NCH₂Py), 4.46 (d[AB], ²J_H,Hϭ 14.1 Hz, 2 H, NCH₂Py), 3.84 (s,

3 H, NCH₃), 3.22 (m, 2 H, CH₂CH₂), 2.92 (br.t, ³J_H,Hϭ 10.3 Hz, 2

1

spectroscopy. The data for 8bPF₆are given: H NMR (500 MHz,

3

H, CH₂CH₂), 2.53 (br.t, J_H,Hϭ 10.9 Hz, 2 H, CH₂CH₂), 2.25 (s,

3

CD₃CN, 298 K): δ ϭ 8.86 (d, J_H,Hϭ 5.4 Hz, 1 H, Py_a-H6), 8.56

3 H, NCH₃), 1.72 (m, 2 H, CH₂CH₂) ppm; ¹³C{¹H} NMR

(100 MHz, [D₆]acetone, 243 K): δ ϭ 160.0 (Py-C2/6), 158.1 (Py-

C2/6), 138.4 (Py-C4), 126.3 (Py-C3/5), 121.9 (Py-C3/5), 68.1

(NCH₂Py), 65.4 (NCH₂Py), 57.7 (br., CH₂CH₂), 52.6 (NCH₃), 46.6

(br., CH₂CH₂), 37.7 (NCH₃) ppm. ESI-MS (CH₃CN): 427 [M Ϫ

PF₆]^ϩ, 399 [M Ϫ (CH₂CH₂) Ϫ PF₆]^ϩ.

3

4

(d, J_H,Hϭ 5.4 Hz, 2 H, Py_b-H6), 7.83 (dt, J_H,Hϭ 7.8, J_H,H

ϭ

3

1.4 Hz, 2 H, Py_b-H4),7.63 (t, J_H,Hϭ 7.3 Hz, 1 H, Py_a-H4), 7.48

3

(d, J_H,Hϭ 7.8 Hz, 2 H, Py_b-H3), 7.35 (t, J_H,Hϭ 6.6 Hz, 2 H,

Py_b-H5), 7.25 (m, 1 H, Py_a-H5), 7.14 (d, ³J_H,Hϭ 7.8 Hz, 1 H, Py_a-

2

H3), 5.12 (d[AB], J_H,Hϭ 15.6 Hz, 2 H, NCH₂Py_b), 5.00 (d[AB],

²J_H,Hϭ 15.6 Hz, 2 H, NCH₂Py_b), 4.80 (s, 2 H, NCH₂Py_a), 3.55

3

2

( E t h e n e ) { 3 , 1 1 - d i m e t h y l - 3 , 1 1 , 1 7 , 1 8 - t e t r a a z a t r i -

cyclo[11.3.1.1^5,9]octadeca-1(17),5(18),6,8,13,15-hexaene-

(dt, J_H,Hϭ 6.1, J_H,Rhϭ 2.4 Hz, 2 H, RhCH₂CH₂OO), 3.41 (t,

³J_H,Hϭ 6.1 Hz, 2 H, RhCH₂CH₂OO) ppm; ¹³C{¹H} NMR

(50 MHz, CD₃CN, 300 K): δ ϭ 164.6 (Py_b-C2), 162.7 (Py_a-C6),

152.5 (Py_a-C6), 150.5 (Py_b-C6), 139.7 (Py_b-C4), 138.7 (Py_a-C4),

125.9 (Py_b-C3), 125.5 (Py_a-C3), 124.6 (Py_b-C5), 122.6 (Py_a-C5),

72.8 (RhCH₂CH₂OO), 67.9 (NCH₂Py_b), 65.4 (NCH₂Py_a), 44.8 (d,

¹J_C,Rhϭ 28.8 Hz, RhCH₂CH₂OO) ppm. ESI-MS (CD₃CN): 453

[M Ϫ PF₆]^ϩ, 425 [M Ϫ CH₂CH₂Ϫ PF₆]^ϩ, 409 [M Ϫ C₂H₄O Ϫ

κ⁴N¹,N²,N³,N⁴}rhodium(

I) Hexafluorophosphate (6PF₆): After stir-

ring 5PF₆(245 mg, 0.43 mmol) in [D₆]acetone (10 mL) for 4 hours,

diethyl ether (40 mL) was added. A red solid precipitated and was

collected by filtration and washed with diethyl ether. The obtained

brick-red solid was isolated by filtration, washed with diethyl ether

and dried in vacuo. Yield 112 mg (48%). ¹H NMR (200 MHz,

3

PF₆]^ϩ, 393 [M Ϫ C₂H₄O₂Ϫ PF₆]^ϩ, 391 [M Ϫ C₂H₄O₂ϪH₂

Ϫ

CD₃CN, 298 K): δ ϭ 7.62 (t, J_H,Hϭ 7.9 Hz, 2 H, Py-H4), 7.11

3

2

PF₆]^ϩ.

(d, J_H,Hϭ 7.8 Hz, 4 H, Py-H3 and Py-H5), 4.01 (d[AB], J_H,H

ϭ

2

15.1 Hz, 4 H, NCH₂Py), 3.82 (d[AB], J_H,Hϭ 15.0 Hz, 4 H,

(2-Peroxyethyl-κ²C¹,O²)[N,N,N-tris(2-pyridylmethyl-κN)-

amine-κN]iridium(III Tetraphenylborate (10aBPh₄): Compound

2

NCH₂Py), 2.54 (d, J_H,Rhϭ 2.4 Hz, 4 H, CH₂CH₂), 2.15 (d,

)

³J_H,Rhϭ 1.3 Hz, 6 H, NCH₃) ppm; ¹³C{¹H} NMR (75 MHz,

[D₆]acetone, 297 K): δ ϭ 155.4 (Py-C2 and Py-C6), 136.6 (Py-C4),

121.3 (Py-C3 and Py-C5), 76.1 (NCH₂Py), 49.8 (NCH₃), 24.8 (d,

J_C,Rhϭ 18 Hz, CH₂CH₂) ppm. ESI-MS (CH₃CN): 399 [M Ϫ

PF₆]^ϩ, 371 [M Ϫ (CH₂CH₂) Ϫ PF₆]^ϩ.

4BPh₄was ground with a mortar and exposed to air for 5 days.

10aBPh₄was obtained in Ͼ 90% yield, as determined by ¹H NMR

spectroscopy.^{[11] 1}H NMR (500 MHz, CD₃CN, 243 K): δ ϭ 8.67

3

4

(m, 3 H, Py-H6), 7.77 (dt, J_H,Hϭ 7.8, J_H,Hϭ 1.6 Hz, 2 H, Py_b-

3

4

H4), 7.68 (dt, J_H,Hϭ 7.8, J_H,Hϭ 1.6 Hz, 1 H, Py_a-H4), 7.38 (d,

(2-Peroxyethyl-κ²C¹,O²)[N,N,N-tris(2-pyridylmethyl-κN)-

³J_H,Hϭ 7.7 Hz, 2 H, Py_b-H3), 7.30 (m, 3 H, Py-H5), 7.26 (m, 8 H,

3

amine-κN]rhodium(III

)

Tetraphenylborate (8aBPh₄): Compound

BAr-H2), 7.16 (d, J_H,Hϭ 7.7 Hz, 1 H, Py_a-H3), 6.98 (t, J_H,H

ϭ

Eur. J. Inorg. Chem. 2003, 1072Ϫ1087

1083

A. W. Gal et al.

7.5 Hz, 8 H, BAr-H3), 6.82 (t, ³J_H,Hϭ 7.3 Hz, 4 H, BAr-H4), 4.92 5.6 Hz, 2 H, Py_b-H6), 7.84 (dt, J_H,Hϭ 7.8, J_H,Hϭ 1.6 Hz, 2 H,

FULL PAPER

3

4

2

(d[AB], J_H,Hϭ 15.4 Hz, 2 H, NCH₂Py_b), 4.67 (d[AB], J_H,H

ϭ

Py_b-H4), 7.73 (dt, ³J_H,Hϭ 7.8, ⁴J_H,Hϭ 1.6 Hz, 1 H, Py_a-H4), 7.32

15.4 Hz, 2 H, NCH₂Py_b), 4.56 (s, 2 H, NCH₂Py_a), 2.54 (t, ³J_H,Hϭ (m, 6 H, Py-H3 and Py-H5), 7.27 (m, 8 H, BAr-H2), 6.99 (t,

3

6.2 Hz, 2 H, RhCH₂CH₂OO), 2.03 (t, J_H,Hϭ 6.2 Hz, 2 H, ³J_H,Hϭ 7.4 Hz, 8 H, BAr-H3), 6.83 (t, J_H,Hϭ 7.2 Hz, 4 H, BAr-

RhCH₂CH₂OO) ppm; ¹³C{¹H} NMR (125 MHz, CD₃CN, 243 K):

H4), 5.01 (d[AB], J_H,Hϭ 15.9 Hz, 2 H, NCH₂Py_b), 4.71 (d[AB],

2

1

δ ϭ 164.8 (Py_b-C2), 163.9 (q, J (C,B)ϭ 49.2 Hz, BAr-C1), 159.3 ²J_H,Hϭ 14.9 Hz, NCH₂Py_b), 4.67 (s, 2 H, NCH₂Py_a), 2.69 (dd,

(Py_a-C2), 149.0 (Py_b-C6), 148.1 (Py_a-C6), 138.5 (Py_a-C4), 138.0 ³J_H,Hϭ 5.1, J_H,Rhϭ 2.9 Hz, 2 H, RhCH₂CHO) ppm; ¹³C{¹H}

2

3

(Py_b-C4), 135.8 (q, J_C,Bϭ 1.3 Hz, BAr-C2), 126.1 (q, J_C,B

2.9 Hz, BAr-C3), 124.9 (Py_b-C3/5 and Py_a-C3/5), 123.9 (Py_b-C3/5), (q, ¹J_C,Bϭ 49.2 Hz, BAr-C1), 162.4 (Py_b-C2), 159.0 (Py_a-C2), 149.9

122.1 (BAr-C4), 121.3 (Py_a-C3/5), 72.1 (NCH₂Py_b), 71.8 (Py_b-C6), 147.2 (Py_a-C6), 139.3 (Py_b-C4), 139.2 (Py_a-C4), 135.7

(NCH₂Py_αor IrCH₂CH₂OO), 71.1 (NCH₂Py_αor IrCH₂CH₂OO), (BAr-C2), 126.1 (q, J_C,Bϭ 2.7 Hz, BAr-C3), 125.4 (Py_b-C5/C3),

ϭ

NMR (125 MHz, CD₃CN, 243 K): δ ϭ 209.0 (RhCH₂CHO), 163.9

3

15.8 (IrCH₂CH₂OO) ppm.

124.9 (Py_a-C5/C3), 124.4 (Py_b-C5/C3), 122.1 (BAr-C4), 121.2 (Py_a-

1

C5/C3), 70.7 (NCH₂Py_a), 68.3 (NCH₂Py_b), 26.9 (d, J_C,Rh

ϭ

(2-Peroxyethyl-κ²C¹,O²)[N,N,N-tris(2-pyridylmethyl-κN)-

21.0 Hz, RhCH₂CHO) ppm. ESI-MS (CD₃CN): 453 [M Ϫ BPh₄]^ϩ,

435 [M Ϫ H₂O Ϫ BPh₄]^ϩ, 425 [M Ϫ C₂H₄Ϫ BPh₄]^ϩ, 409 [M Ϫ

C₂H₄O Ϫ BPh₄]^ϩ, 393 [M Ϫ C₂H₄O₂Ϫ BPh₄]^ϩ, 391 [M Ϫ C₂H₄O₂

amine-κN]iridium(III

)

Hexafluorophosphate

(10aPF₆/10bPF₆):

Compound 4PF₆was ground with a mortar and exposed to air for

5 days.^[11]A mixture of the isomeric 3-irida-1,2-dioxolanes 10aPF₆

and 10bPF₆in an approximate ratio of 2:5 was formed in Ͼ 90%

yield, as determined by ¹H NMR spectroscopy. The data for

Ϫ H₂Ϫ BPh₄]^ϩ. IR (KBr): ν˜ ϭ 1655 cm^Ϫ1

.

(Formylmethyl-κC¹)(hydroxy)-[N,N,N-tris(2-pyridylmethyl-

κN)amine-κN]rhodium(III Hexafluorophosphate (9aPF₆/9bPF₆):

1

)

10bPF₆are given: H NMR (500 MHz, CD₃CN, 243 K): δ ϭ 8.93

3

Solid 8aPF₆/8bPF₆was exposed to a N₂atmosphere saturated with

H₂O for three days at room temperature. A mixture of 9aPF₆and

9bPF₆in an approximate ratio of 1:1 was obtained in Ͼ 90% yield,

according to ¹H NMR spectroscopy. The data for 9bPF₆are given:

¹H NMR (500 MHz, CD₃CN, 243 K): δ ϭ 9.98 (t, ³J_H,Hϭ 4.9 Hz,

1 H, RhCH₂CHO), 8.68 (d, ³J_H,Hϭ 5.5 Hz, 2 H, Py_b-H6), 8.53 (d,

³J_H,Hϭ 5.5 Hz, 1 H, Py_a-H6), 7.84 (m, 2 H, Py_b-H4), 7.66 (dt,

³J_H,Hϭ 7.7, ⁴J_H,Hϭ 1.5 Hz, 1 H, Py_a-H4), 7.48 (d, ³J_H,Hϭ 8.2 Hz,

(d, J_H,Hϭ 5.5 Hz, 1 H, Py_a-H6), 8.58 (d, J_H,Hϭ 5.13 Hz, 2 H,

Py_b-H6), 7.75 (dt, ³J_H,Hϭ 7.8, ⁴J_H,Hϭ 1.3 Hz, 2 H, Py_b-H4), 7.56

3

4

3

(dt, J_H,Hϭ 7.8, J_H,Hϭ 1.3 Hz, 1 H, Py_a-H4), 7.42 (d, J_H,H

ϭ

3

8.1 Hz, 2 H, Py_b-H3), 7.27 (t, J_H,Hϭ 6.2 Hz, 2 H, Py_b-H5), 7.15

(m, 2 H, Py_a-H5 and Py_a-H3), 5.04 (d[AB], J_H,Hϭ 15.4 Hz, 2 H,

2

NCH₂Py_b), 4.94 (d[AB], ²J_H,Hϭ 15.8 Hz, 2 H, NCH₂Py_b), 4.76 (s,

2 H, NCH₂Py_a), 2.69 (t, ³J_H,Hϭ 6.7 Hz, 2 H, IrCH₂CH₂OO), 2.63

(t, ³J_H,Hϭ 6.7 Hz, 2 H, IrCH₂CH₂OO) ppm. ¹³C NMR (125 MHz,

CD₃CN, 243 K): δ ϭ 165.9 (Py_b-C2), 162.6 (Py_a-C2), 152.4 (Py_a-

C6), 149.5 (Py_b-C6), 138.7 (Py_b-C4), 137.3 (Py_a-C4), 125.3 (Py_b-

C3/5), 125.1 (Py_a-C3/5), 124.2 (Py_b-C3/5), 121.8 (Py_a-C3/5), 71.6

(IrCH₂CH₂OO), 69.2 (NCH₂Py_b), 66.4 (NCH₂Py_a), 23.9 (IrCH_2-

CH₂OO) ppm.

3

2 H, Py_b-H3), 7.36 (t, J_H,Hϭ 6.6 Hz, 2 H, Py_b-H5), 7.28 (t,

3

³J_H,Hϭ 6.6 Hz, 1 H, Py_a-H5), 7.17 (d, J_H,Hϭ 8.8 Hz, 1 H, Py_a-

2

H3), 5.39 (d[AB], J_H,Hϭ 15.0 Hz, 2 H, NCH₂Py_b), 4.88 (s, 2 H,

2

NCH₂Py_a), 4.76 (d[AB], J_H,Hϭ 15.0 Hz, 2 H, NCH₂Py_b), 3.47

3

2

(dd, J_H,Hϭ 4.8, J_H,Rhϭ 2.9 Hz, 2 H, RhCH₂CHO) ppm;

¹³C{¹H} NMR (125 MHz, CD₃CN, 243 K): δ ϭ 210.8 (d, ²J_C,Rhϭ

9.6 Hz, RhCH₂CHO), 165.0 (Py_b-C2), 163.5 (Py_a-C2), 151.5 (Py_b-

C6), 150.2 (Py_a-C6), 139.6 (Py_b-C4), 138.8 (Py_a-C4), 125.4 (Py_b-

C5/C3), 125.1 (Py_a-C5/C3), 124.4 (Py_b-C5/C3), 122.1 (Py_a-C5/C3),

(2-Peroxyethyl-κ²C¹,O²){3,11-dimethyl-3,11,17,18-tetra-

azatricyclo[11.3.1.1^{5 , 9}]octadeca-1(17),5(18),6,8,13,15-

hexaene-κ⁴N¹,N²,N³,N⁴}rhodium(III) Hexafluorophosphate (16PF₆):

Complex 6PF₆was exposed to an oxygen atmosphere at room tem-

perature for 5 days at atmospheric pressure.^[11]The color changed

from red to yellow ochre. ¹H NMR (200 MHz, CD₃CN, 298 K):

1

66.4 (NCH₂Py_b), 66.2 (NCH₂Py_a), 34.5 (d, J_C,Rhϭ 25.0 Hz,

RhCH₂CHO) ppm. ESI-MS (CH₃CN): 453 [M Ϫ PF₆]^ϩ.

(Formylmethyl-κC¹)(aqua)[N,N,N-tris(2-pyridylmethyl-κN)-

amine-κN]rhodium(III) Tetraphenylborate Tetra[3,5-bis(trifluorome-

thyl)phenyl]borate (20a[BPh₄][BAr^F₄]): HBAr^F₄(57 mg, 0.11 mmol)

was added to a solution of 8aBPh₄(40 mg, 0.1 mmol) in CD₃CN

(1.0 mL) under N₂. 20a(BPh₄)(BAr^F₄) was obtained in approxim-

ately 85% yield, as determined by ¹H NMR spectroscopy. ¹H NMR

3

δ ϭ 7.75 (t, J_H,Hϭ 7.9 Hz, 1 H, Py-H4), 7.66 (t, J_H,Hϭ 7.9 Hz,

3

1 H, Py-H4), 7.28 (d, J_H,Hϭ 7.8 Hz, 2 H, Py-H3/5), 7.14 (d,

³J_H,Hϭ 7.8 Hz, 2 H, Py-H3/5), 4.57 (d[AB], ²J_H,Hϭ 15.3 Hz, 2 H,

2

NCH₂Py), 4.36 (d[AB], J_H,Hϭ 16.6 Hz, 2 H, NCH₂Py), 4.16

2

3

(d[AB], J_H,Hϭ 15.2 Hz, 4 H, NCH₂Py), 3.66 (dt, J_H,Hϭ 6.4,

³J_H,Rhϭ 0.7 Hz, 2 H, RhCH₂CH₂OO), 2.90 (dt, J_H,Hϭ 6.5,

3

(200 MHz, CD₃CN, 300 K): δ ϭ 9.51 (t, J_H,Hϭ 4.8 Hz, 1 H,

²J_H,Rhϭ 2.5 Hz, 2 H, RhCH₂CH₂OO), 2.71 (d, J_H,Rhϭ 1.2 Hz,

3

RhCH₂CHO), 8.96 (d, J_H,Hϭ 5.5 Hz, 1 H, Py_a-H6), 8.52 (d,

6 H, NCH₃) ppm; ¹³C{¹H} NMR (125 MHz, CD₃CN, 243 K): δ ϭ

157.0 (Py-C2/6), 155.0 (Py-C2/6), 139.3 (Py-C4), 138.2 (Py-C4),

121.6 (Py-C3/5), 120.8 (Py-C3/5), 74.4 (NCH₂Py), 72.5 (NCH₂Py),

71.7 (RhCH₂CH₂OO), 50.1 (NCH₃), 30.3 (d, J_C,Rhϭ 25 Hz,

RhCH₂CH₂OO) ppm. ESI-MS (CH₃CN): 431 [M Ϫ PF₆]^ϩ.

3

4

³J_H,Hϭ 5.7 Hz, 2 H, Py_b-H6), 7.95 (dt, J_H,Hϭ 7.8, J_H,H

ϭ

3

4

1.6 Hz, Py_b-H4), 7.81 (dt, J_H,Hϭ 7.8, J_H,Hϭ 1.6 Hz, Py_a-

H4),7.73 (m, 8 H, BAr^F₄-H2), 7.68 (s, 4 H, BAr^F₄-H4), 7.6Ϫ7.4 (m,

5 H, Py_b-H3, Py_b-H5 and Py_a-H3/5), 7.33 (m, 8 H, BAr-H2), 7.21

(m, 1 H, Py_a-H3/5), 7.01 (t, ³J_H,Hϭ 7.4 Hz, 8 H, BAr-H3), 6.85 (t,

³J_H,Hϭ 6.9 Hz, 4 H, BAr-H4), 5.15 (d[AB], ²J_H,Hϭ 16.4 Hz, 2 H,

NCH₂Py_b), 4.82 (s, 2 H, NCH₂Py_a), 4.69 (d[AB], ²J_H,Hϭ 16.6 Hz,

(Formylmethyl-κC¹)(hydroxy)[N,N,N-tris(2-pyridylmethyl-

κN)amine-κN]rhodium(III) Tetraphenylborate (9aBPh₄). Method A:

A stirred solution of 8aBPh₄in CD₃CN under nitrogen was ex-

posed to the glass-filtered light of a high pressure mercury vapor

lamp^[34]for 90 minutes at Ϫ30 °C. 9aBPh₄was obtained in Ͼ 90%

3

2

2 H, NCH₂Py_b), 3.05 (dd, J_H,Hϭ 4.9, J_H,Rhϭ 2.7 Hz, 2 H,

RhCH₂CHO) ppm; ¹³C{¹H} NMR (125 MHz, CD₃CN, 243 K):

2

1

δ ϭ 206.7 (d, J_C,Rhϭ 1.9 Hz, RhCH₂CHO), 164.0 (q, J_C,B

ϭ

1

49.2 Hz, BAr-C1), 161.9 (q, ¹J_C,Bϭ 49.8 Hz, BAr^F-C1), 161.6 (Py_b-

C2), 158.0 (Py_a-C2), 151.5 (Py_b-C6), 148.7 (Py_a-C6), 140.9 (Py_b-

C4), 140.4 (Py_a-C4), 135.8 (BAr-C2), 134.9 (BAr^F-C2), 129.0 (qq,

yield, as determined by H NMR spectroscopy.

Method B: HBAr^F₄(5.5 mg, 5.4 µmol) was added to a solution of

8aBPh₄(41.8 mg, 54 µmol) in CD₃CN (1 mL) under N₂. 9aBPh₄

was obtained in approximately 70% yield in approximately 1 hour,

²J_C,Fϭ 31.4, J_C,Bϭ 2.9 Hz, BAr^F-C3), 126.4 (Py_b-C5/C3), 126.2

3

as determined by ¹H NMR spectroscopy. ¹H NMR (200 MHz,

(q, ³J_C,Bϭ 2.6 Hz, BAr-C3), 125.8 (Py_a-C5/C3), 125.4 (Py_b-C5/C3),

3

CD₃CN, 300 K): δ ϭ 9.26 (t, J_H,Hϭ 5.0 Hz, 1 H, RhCH₂CHO), 124.6 (q, ¹J_C,Fϭ 271.9 Hz, BAr^F-CF₃), 122.3 (BAr-C4), 122.1 (Py_a-

3

1

9.21 (br.d, J_H,Hϭ 6.0 Hz, 1 H, Py_a-H6), 8.62 (br.d, J_H,H

ϭ

C5/C3), 73.5 (NCH₂Py_a), 69.6 (NCH₂Py_b), 27.8 (d, J_C,Rh

ϭ

1084

Eur. J. Inorg. Chem. 2003, 1072Ϫ1087

3-Metalla-1,2-dioxolanes and Their Reactivity

FULL PAPER

20.4 Hz, RhCH₂CHO) ppm. (The signal for BAr^F-C4 is obscured

by one of the solvent signals). ESI-MS (CH₃CN): 227 [M Ϫ BPh₄

Ϫ PF₆]^ϩ. ESI-MS (CH₃CN): 431 [M Ϫ PF₆]^ϩ, 413 [M Ϫ H₂O Ϫ

PF₆]^ϩ, 287 [M Ϫ C₂H₄O Ϫ PF₆]^ϩ, 371 [M Ϫ C₂H₄O₂Ϫ PF₆]^ϩ,

Ϫ BAr^F₄]^2ϩ, 218 [M Ϫ H₂O Ϫ BPh₄Ϫ BAr^F₄]^2ϩ

.

369 [M Ϫ C₂H₄O₂Ϫ H₂Ϫ PF₆]^ϩ. IR (CD₃CN): ν˜ ϭ 1651 cm^Ϫ1

.

(Formylmethyl-κC¹)(hydroxy)[N,N,N-tris(2-pyridylmethyl-

κN)amine-κN]iridium(III) Tetraphenylborate (11aBPh₄): A solution

of 10aBPh₄(85.2 mg, 99 µmol) in CH₃CN (1 mL) was stirred at

room temperature. After 4 hours, diethyl ether was added and a

yellow solid precipitated. After filtration, the solid was washed with

(Formylmethyl-κC¹)(hydrogen

carbonate)[N,N,N-tris(2-pyridyl-

methyl-κN)amine-κN]rhodium(III) Tetraphenylborate (21aBPh₄): A

solution of 9aBPh₄was left standing under a CO₂atmosphere.

21aBPh₄was formed within 5 minutes in a quantitative yield, ac-

cording to ¹H NMR spectroscopy. Isolation of 21aBPh₄was not

possible, since the insertion of CO₂is a reversible reaction. Precip-

1

diethyl ether and dried in vacuo. Yield: 49.1 mg (58%). H NMR

3

(500 MHz, CD₃CN, 298 K): δ ϭ 9.25 (br.d, J_H,Hϭ 5.7 Hz, 1 H, itation and filtration led to the isolation of 9aBPh₄. ¹H NMR

3

Py_a-H6), 9.21 (t, J_H,Hϭ 5.1 Hz, 1 H, IrCH₂CHO), 8.71 (d, (200 MHz, CD₃CN, 298 K): δ ϭ 9.53 (t, J_H,Hϭ 4.6 Hz, 1 H,

3

4

3

³J_H,Hϭ 5.7 Hz, 2 H, Py_b-H6), 7.78 (dt, J_H,Hϭ 7.8, J_H,H

ϭ

RhCH₂CHO), 8.99 (d, J_H,Hϭ 4.8 Hz, 1 H, Py_a-H6), 8.86 (d,

3

4

3

4

1.5 Hz, 2 H, Py_b-H4), 7.68 (dt, J_H,Hϭ 7.8, J_H,Hϭ 1.6 Hz, 1 H,

³J_H,Hϭ 5.8 Hz, 2 H, Py_b-H6), 7.85 (dt, J_H,Hϭ 7.8, J_H,H

ϭ

3

4

Py_a-H4), 7.4Ϫ7.1 (m, 6 H, Py-H3 and Py-H5), 7.29 (m, 8 H, BAr- 1.6 Hz, 2 H, Py_b-H4), 7.73 (dt, J_H,Hϭ 7.7, J_H,Hϭ 1.6 Hz, 1 H,

H2), 7.00 (t, ³J_H,Hϭ 7.4 Hz, 8 H, BAr-H3), 6.84 (t, ³J_H,Hϭ 7.2 Hz, Py_a-H4), 7.5Ϫ7.2 (m, 5 H, Py-H5 and Py_b-H3), 7.29 (m, 8 H, BAr-

4 H, BAr-H4), 4.86 (s, 2 H, NCH₂Py_b), 4.85 (s, 2 H, NCH₂Py_b), H2), 7.15 (d, ³J_H,Hϭ 7.9 Hz, 1 H, Py_a-H3), 6.99 (t, ³J_H,Hϭ 7.4 Hz,

4.56 (s, 2 H, NCH₂Py_a), 3.07 (d, ³J_H,Hϭ 5.3 Hz, 2 H, IrCH₂CHO) 8 H, BAr-H3), 6.84 (t, ³J_H,Hϭ 7.2 Hz, 4 H, BAr-H4), 4.99 (d[AB],

ppm; ¹³C{¹H} NMR (125 MHz, CD₃CN, 298 K): δ ϭ 209.4

²J_H,Hϭ 16.2 Hz, 2 H, NCH₂Py_b), 4.58 (s, 2 H, NCH₂Py_a), 4.50

1

2

3

(IrCH₂CHO), 165.8 (Py_b-C2), 164.6 (q, J (C,B)ϭ 49.3 Hz, BAr-

(d[AB], J_H,Hϭ 15.8 Hz, 2 H, NCH₂Py_b), 3.23 (dd, J_H,Hϭ 4.8,

C1), 160.8 (Py_a-C2), 149.7 (Py_b-C6), 146.3 (Py_a-C6), 139.2 (Py_a- ²J_H,Rh

ϭ

2.5 Hz,

2

H, RhCH₂CHO) ppm; ¹³C{¹H} NMR

3

1

C4), 139.0 (Py_b-C4), 136.5 (BAr-C2), 126.4 (q, J_C,Bϭ 2.8 Hz, (50 MHz, CD₃CN): δ ϭ 210.1 (RhCH₂CHO), 164.6 (q, J_C,B

ϭ

BAr-C3), 125.7 (Py_b-C3/5), 125.1 (Py_a-C3/5), 124.7 (Py_b-C3/5), 49.3 Hz, BAr-C1), 162.3 (Py_b-C2), 158.4 (Py_a-C2), 152.2 (Py_b-C6),

122.6 (BAr-C4), 121.5 (Py_a-C3/5), 72.9 (NCH₂Py_a), 71.4 148.4 (Py_a-C6), 140.4 (Py_b-C4), 140.1 (Py_a-C4), 136.5 (BAr-C2),

(NCH₂Py_b), 16.3 (IrCH₂CHO) ppm. ESI-MS (CH₃CN): 543 [M Ϫ

126.40 (q, ³J_C,Bϭ 2.6 Hz, BAr-C3), 125.9 (Py_b-C3/5), 125.5 (CO₂),

BPh₄]^ϩ, 525 [M Ϫ H₂O Ϫ BPh₄]^ϩ, 499 [M Ϫ C₂H₄O Ϫ BPh₄]^ϩ, 124.9 (Py_b-C3/5), 122.6 (BAr-C4), 121.9 (Py_a-C3/5), 73.2

483 [M Ϫ C₂H₄O₂Ϫ BPh₄]^ϩ, 391 [M Ϫ CH₂C₅H₄N Ϫ H₄O₂

Ϫ

(NCH₂Py_a), 70.0 (NCH₂Py_b), 28.1 (d, J_C,Rh

ϭ

20.7 Hz,

1

BPh₄]^ϩ. IR (KBr): ν˜ ϭ 1654 cm^Ϫ1

.

RhCH₂CHO) ppm. (The signal for Py_a-C3/5 is obscured by one of

the other signals). IR (CD₃CN): ν˜ ϭ 1694, 1664 cm^Ϫ1

.

(Formylmethyl-κC¹)(hydroxy)[N,N,N-tris(2-pyridylmethyl-

κN)amine-κN]iridium(III) Hexafluorophosphate (11aPF₆/11bPF₆): (Formylmethyl-κC¹)(hydrogen

carbonate)[N,N,N-tris(2-pyridyl-

11aPF₆/11bPF₆was prepared by a procedure similar to that of

methyl-κN)amine-κN]iridium(III

22aBPh₄was prepared by a procedure similar to that of 21aBPh₄,

)

Tetraphenylborate (22aBPh₄):

11aBPh₄, using 10aPF₆/10bPF₆instead of 10aBPh₄. Yield: 93%. ¹H

NMR (500 MHz, CD₃CN, 298 K): δ ϭ 10.11 (t, ³J_H,Hϭ 5.0 Hz, 1 using 11aBPh₄instead of 9aBPh₄. Complex 22aBPh₄was also ob-

3

H, IrCH₂CHO), 8.73 (d, J_H,Hϭ 5.9 Hz, 3 H, Py-H6), 7.81 (dt, tained in a quantitative yield, according to ¹H NMR spectroscopy,

4

3

³J_H,Hϭ 7.7, J_H,Hϭ 1.5 Hz, 2 H, Py_b-H4), 7.61 (dt, J_H,Hϭ 7.7,

but could not be isolated. ¹H NMR (500 MHz, CD₃CN, 298 K):

⁴J_H,Hϭ 1.5 Hz, 1 H, Py_a-H4), 7.48 (d, J_H,Hϭ 8.1 Hz, 2 H, Py_b- δ ϭ 9.46 (t, J_H,Hϭ 4.8 Hz, 1 H, IrCH₂CHO), 9.02 (d, J_H,H

H3), 7.30 (t, ³J_H,Hϭ 6.4 Hz, 2 H, Py_b-H5), 7.23 (t, ³J_H,Hϭ 6.8 Hz, 5.5 Hz, 1 H, Py_a-H6), 8.95 (d, J_H,Hϭ 5.5 Hz, 2 H, Py_b-H6), 7.82

ϭ

3

4

3

1 H, Py_a-H5), 7.17 (d, J_H,Hϭ 7.7 Hz, 1 H, Py_a-H3), 5.40 (d,

(dt, J_H,Hϭ 7.9, J_H,Hϭ 1.5 Hz, 2 H, Py_b-H4), 7.71 (dt, J_H,Hϭ

²J_H,Hϭ 15.0 Hz, 2 H, NCH₂Py_b), 4.82 (s, 2 H, NCH₂Py_a), 4.77 (d, 7.7, J_H,Hϭ 1.5 Hz, 1 H, Py_a-H4), 7.44 (d, J_H,Hϭ 7.7 Hz, 2 H,

4

3

²J_H,Hϭ 14.7 Hz, 2 H, NCH₂Py_b), 3.66 (d, J_H,Hϭ 4.8 Hz, 2 H,

Py_b-H3), 7.40 (t, J_H,Hϭ 6.6 Hz, 1 H, Py_a-H5), 7.33 (t, J_H,H

ϭ

3

IrCH₂CHO) ppm; ¹³C{¹H} NMR (125 MHz, CD₃CN, 300 K): δ ϭ 6.6 Hz, 2 H, Py_b-H5), 7.29 (m, 8 H, BAr-H2), 7.18 (d, J_H,H

3

211.2 (IrCH₂CHO), 167.1 (Py_b-C2), 164.9 (Py_a-C2), 152.0 (Py_b- 8.0 Hz, 1 H, Py_a-H3), 6.99 (t, J_H,Hϭ 7.3 Hz, 8 H, BAr-H3), 6.84

C6), 151.1 (Py_a-C6), 139.5 (Py_b-C4), 138.4 (Py_a-C4), 125.9 (Py_b-

(t, ³J_H,Hϭ 7.1 Hz, 4 H, BAr-H4), 4.93 (d[AB], ²J_H,Hϭ 15.3 Hz, 2

C3/5), 125.7 (Py_a-C3/5), 124.5 (Py_b-C3/5), 122.2 (Py_a-C3/5), 69.3 H, NCH₂Py_b), 4.75 (d[AB], ²J_H,Hϭ 15.7 Hz, 2 H, NCH₂Py_b), 4.55

(NCH₂Py_a), 68.6 (NCH₂Py_b), 20.7 (IrCH₂CHO) ppm. ESI-MS (s, 2 H, NCH₂Py_a), 3.39 (d, ³J_H,Hϭ 4.8 Hz, 2 H, IrCH₂CHO) ppm;

(CH₃CN): 543 [M Ϫ PF₆]^ϩ, 541 [M Ϫ H₂Ϫ PF₆]^ϩ.

¹³C{¹H} NMR (125 MHz, CD₃CN, 298 K): δ ϭ 211.1 (IrCH_2-

CHO), 164.6 (q, ¹J (C,B)ϭ 49.4 Hz, BAr-C1), 164.5 (Py_b-C2),

159.9 (Py_a-C2), 152.4 (Py_b-C6), 147.9 (Py_a-C6), 139.8 (Py_a-C4),

139.7 (Py_b-C4), 136.5 (BAr-C2), 126.4 (q, ³J_C,Bϭ 2.8 Hz, BAr-C3),

125.9 (Py_b-C3/5), 125.6 (Py_b-C3/5), 124.7 (Py_a-C3/5), 122.6 (BAr-

C4), 121.8 (Py_a-C3/5), 74.9 (NCH₂Py_a), 72.1 (NCH₂Py_b), 14.8

(IrCH₂CHO) ppm. ESI-MS (CO₂saturated CH₃CN): 587 [M Ϫ

BPh₄]^ϩ, 543 [M Ϫ CO₂Ϫ BPh₄]^ϩ. IR (CH₃CN): ν˜ ϭ 1663, 1635

(Formylmethyl-κC¹)(hydroxy){3,11-dimethyl-3,11,17,18-

tetraazatricyclo[11.3.1.1^5,9]octadeca-1(17),5(18),6,8,13,15-

hexaene-κ⁴N¹,N²,N³,N⁴}rhodium(III) Hexafluorophosphate (17PF₆):

Solid 16PF₆was put under a nitrogen atmosphere saturated with

1

H₂O vapor for 4 days. The product was dried in vacuo. H NMR

3

(400 MHz, CD₃CN, 297 K): δ ϭ 9.57 (t, J_H,Hϭ 5.4 Hz, 1 H,

3

CHO), 7.77 (t, J_H,Hϭ 7.8 Hz, 1 H, Py-H4), 7.66 (t, J_H,H

ϭ

cm^Ϫ1

(d, J_H,Hϭ 8.0 Hz, 2 H, Py-H3/5), 4.76 (d[AB], J_H,Hϭ 16.5 Hz, (Propene)[N,N,N-tris(2-pyridylmethyl-κN)amine-κN]-

2 H, NCH₂Py), 4.51 (d[AB], ²J_H,Hϭ 16.5 Hz, 2 H, NCH₂Py), 4.30 rhodium(

Tetraphenylborate (23BPh₄): Propene was bubbled

.

3

8.0 Hz, 1 H, Py-H4), 7.29 (d, J_H,Hϭ 8.0 Hz, 2 H, Py-H3/5), 7.18

3

2

I)

2

(d[AB], J_H,Hϭ 16.5 Hz, 2 H, NCH₂Py), 4.29 (d[AB], J_H,H

15.9 Hz, 2 H, NCH₂Py), 3.14 (dd, J_H,Hϭ 5.3, J_H,Rhϭ 3.2 Hz, 1

H, RhCH₂CHO), 2.95 (s, 6 H, NCH₃) ppm; ¹³C{¹H} NMR minutes. Tpa (81 mg, 0.28 mmol) was then added, and the reaction

ϭ

through a solution of [(ethene)₂RhCl]₂(54 mg, 0.14 mmol) and

NaHCO₃(50 mg) in MeOH (3 mL) at room temperature for 30

3

(125 MHz, CD₃CN, 243 K): δ ϭ 207.7 (RhCH₂CHO), 157.4 (Py-

C2/6), 155.7 Py-C2/6), 139.9 (Py-C4), 138.7 (Py-C4), 121.4 (Py-C3/ washed with methanol (2 ϫ 0.25 mL) and NaBPh₄(85.5 mg,

5), 74.7 (NCH₂Py), 72.6 (NCH₂Py), 50.8 (NCH₃), 33.4 (d, ¹J_C,Rhϭ

0.25 mmol) was added to the filtrate. The reaction mixture was

21.2 Hz, RhCH₂CHO) ppm. FAB-MS (NPOE, CH₃CN): 431 [M stirred for 1 hour, filtered, washed with MeOH (3 ϫ 1 mL) and

mixture was stirred for 1 hour. After filtration the residue was

Eur. J. Inorg. Chem. 2003, 1072Ϫ1087

1085

A. W. Gal et al.

FULL PAPER

dried in vacuo. Yield: 130 mg (69%). ¹H NMR (200 MHz, [D₆]ace-

for a generous loan of RhCl₃·3H₂O. S. Thewissen, P. M. van Galen,

3

tone, 300 K): δ ϭ 9.39 (d, J_H,Hϭ 4.7 Hz, 1 H, Py-H6), 8.33 (d, and H. I. V. Amatdjais-Groenen are gratefully acknowledged for

3

³J_H,Hϭ 5.5 Hz, 1 H, Py-H6), 8.03 (d, J_H,Hϭ 5.3 Hz, 1 H, Py-

the ESI-MS measurements. Prof. Dr. P. Chen from the ETH Zürich

H6), 7.67 (m, 3 H, Py-H4), 7.35 (m, 11 H, BAr-H2 and Py-H3/5), is kindly acknowledged for allowing us to use the Finnigan TSQ

7.17 (m, 3 H, Py-H3/5), 6.92 (t, ³J_H,Hϭ 7.2 Hz, 8 H, BAr-H3), 6.77 7000 mass spectrometer. Prof. Dr. Hans-Jörg Krüger (Universität

3

2

(t, J_H,Hϭ 6.9 Hz, 4 H, BAr-H4), 5.68 (d[AB], J_H,Hϭ 15.1 Hz, 1 Kaiserslautern, Germany) is kindly acknowledged for providing us

2

H, NCH₂Py), 5.57 (d[AB], J_H,Hϭ 15.1 Hz, 1 H, NCH₂Py), 4.93 with details on the synthesis of N₄Me₂.

(d[AB], J_H,Hϭ 15.3 Hz, 1 H, NCH₂Py), 4.92 (d[AB], J_H,H

2

ϭ

15.5 Hz, 1 H, NCH₂Py), 4.63 (s, 2 H, NCH₂Py), 2.47 (m, 1 H,

CH₂CHCH₃), 2.28 (dm, J_H,Hϭ 7.8 Hz, 1 H, CH₂CHCH₃), 1.93

[1] [1a]

H. Mimoun, M. M. P. Machirant, I. Seree de Roch, J. Am.

3

[1b]

Chem. Soc. 1978, 100(17), 5437Ϫ5444.

G. Read, J. Mol.

3

(dm, J_H,Hϭ 9.8 Hz, 1 H, CH₂CHCH₃), 0.87 (dd, J_H,Hϭ 6.2,

Catal. 1988, 44, 15Ϫ33. ^[1c]M. Bressan, F. Morandini, A. Mor-

villo, P. Rigo, J. Organomet. Chem. 1985, 280, 139Ϫ146. ^[1d]R.

A. Sheldon, J. A. van Doorn, J. Organomet. Chem. 1975, 94,

²J_H,Rh

ϭ

1.3 Hz,

3

H, CH₂CHCH₃) ppm; ¹³C{¹H} NMR

1

(100 MHz, [D₆]acetone, 297 K): δ ϭ 165.0 (q, J_C,Bϭ 49.7 Hz,

BAr-C1), 164.1 (Py-C2), 163.5 (Py-C2), 159.3 (Py-C2), 152.4 (Py-

C6), 151.9 (Py-C6), 151.2 (Py-C6), 138.3 (Py-C4), 137.5 (Py-C4),

137.4 (Py-C4), 137.1 (BAr-C2), 126.1 (m, BAr-C3), 125.5 (Py-C3/

5), 125.2 (Py-C3/5), 124.7 (Py-C3/5), 123.7 (Py-C3/5), 123.4 (Py-

115Ϫ129. ^[1e]H. Mimoun, Angew. Chem. 1982, 21, 734; Angew.

[1f]

Chem. Int. Ed. Engl. 1982, 94, 750Ϫ766.

H. Mimoun, I.

Seree de Roch, L. Sajus, Tetrahedron 1970, 26, 37Ϫ50.

D. V. Deubel, J. Sundermeyer, G. Frenking, J. Am. Chem. Soc.

2000, 122, 10101Ϫ10108.

[2]

C3/5), 122.4 (Py-C3/5), 122.4 (BAr-C4), 70.1 (NCH₂Py), 69.9

[3] [3a]

1

G. Read, M. Urgelles, A. M. R. Galas, M. B. Hursthouse,

(NCH₂Py), 64.6 (NCH₂Py), 40.3 (d, J_C,Rh

ϭ

19.7 Hz,

19.8 Hz,

[3b]

J. Chem. Soc., Dalton Trans. 1983, 911Ϫ913.

L. Pandolfo,

CH₂CHCH₃/CH₂CHCH₃), 33.8 (d, ¹J_C,Rh

ϭ

G. Paiaro, G. Valle, P. Ganis, Gazz. Chim. Ital. 1985, 115,

CH₂CHCH₃/CH₂CHCH₃), 20.6 (CH₂CHCH₃) ppm. ESI-MS

(acetone): 435 [M Ϫ BPh₄], 393 [M Ϫ C₃H₆Ϫ BPh₄], 301 [M Ϫ

C₃H₆Ϫ CH₂C₅H₄N Ϫ BPh₄].

59Ϫ63.

[4] [4a]

M. Krom, R. G. E. Coumans, J. M. M. Smits, A. W. Gal,

Angew. Chem. 2001, 113, 2164Ϫ2166; Angew. Chem. Int. Ed.

2001, 40(11), 2106Ϫ2108. ^[4b]M. Krom, R. G. E. Coumans, J.

M. M. Smits, A. W. Gal, Angew. Chem. 2002, 114, 595Ϫ599;

Angew. Chem. Int. Ed. 2002, 41(4), 575Ϫ579.

(Peroxo-κ²O¹,O²)[N,N,N-tris(2-pyridylmethyl-κN)amine-κN]-

rhodium(III) Tetraphenylborate (24BPh₄): Complex 23BPh₄was ex-

posed to air for 3 days. 24BPh₄was obtained in Ͼ 90% yield, as

determined by ¹H NMR spectroscopy. ¹H NMR (500 MHz,

[5]

B. de Bruin, M. J. Boerakker, J. A. W. Verhagen, R. de Gelder,

J. M. M. Smits, A. W. Gal, Chem. Eur. J. 2000, 6, 298Ϫ312.

3

[6] [6a]

CD₃CN, 233 K): δ ϭ 9.23 (d, J_H,Hϭ 5.5 Hz, 1 H, Py_a-H6), 8.37

B. de Bruin, J. A. Brands, J. J. J. M. Donners, M. P. J.

Donners, R. de Gelder, J. M. M. Smits, A. W. Gal, A. L. Spek,

3

4

(d, J_H,Hϭ 5.1 Hz, 2 H, Py_b-H6), 7.77 (dt, J_H,Hϭ 7.8, J_H,H

ϭ

3

4

[6b]

1.6 Hz, 2 H, Py_b-H4), 7.65 (dt, J_H,Hϭ 7.8, J_H,Hϭ 1.6 Hz, 1 H,

Py_a-H4), 7.34 (d, J_H,Hϭ 7.7 Hz, 2 H, Py_b-H3), 7.28 (m, 11 H,

Chem. Eur. J. 1999, 5, 2921Ϫ2936.

M. Kicken, N. F. A. Suos, M. P. J. Donners, C. J. den Reijer,

A. J. Sandee, R. de Gelder, J. M. M. Smits, A. W. Gal, A. L.

Spek, Eur. J. Inorg. Chem. 1999, 1581Ϫ1592.

B. de Bruin, R. J. N. A.

3

BAr-H2, Py-H5), 7.12 (d, J_H,Hϭ 7.7 Hz, 1 H, Py_a-H3), 6.98 (t,

[6c]

³J_H,Hϭ 7.3 Hz, 8 H, BAr-H3), 6.81 (t, J_H,Hϭ 7.2 Hz, 4 H, BAr-

3

B. de Bruin,

Th. P. J. Peters, J. B. M. Wilting, S. Thewissen, J. M. M. Smits,

A. W. Gal, Eur. J. Inorg. Chem. 2002, 2671.

The X-ray structures of three other iridium bis(ethene) com-

2

H4), 5.21 (d[AB], J_H,Hϭ 16.1 Hz, 2 H, NCH₂Py_b), 4.82 (d[AB],

²J_H,Hϭ 16.1 Hz, 2 H, NCH₂Py_b), 4.53 (s, 2 H, NCH₂Py_a) ppm;

[7]

¹³C{¹H} NMR (125 MHz, CD₃CN, 233 K): δ ϭ 163.8 (q, J_C,B

ϭ

1

plexes stabilized by tridentate nitrogen donor ligands have been

reported:

M. C. Nicasio, M. L. Poveda, P. J. Perez, C. Ruız, C. Bianchini,

E. Carmona, Chem. Eur. J. 1997, 3, 860Ϫ873.

[7a]

49.2 Hz, BAr-C1), 162.8 (Py_b-C2), 159.8 (Py_a-C2), 152.5 (Py_a-C6),

150.1 (Py_b-C6), 139.4 (Py_b-C4), 139.1 (Py_a-C4), 135.6 (BAr-C2),

´

Y. Alvarado, O. Boutry, E. Gutierrez, A. Monge,

´

3

[7b]

126.0 (q, J_C,Bϭ 2.7 Hz, BAr-C3), 125.4 (Py_b-C3/5), 123.4 (Py_b-

J. S. Wiley,

W. J. Oldham, Jr., D. M. Heinekey, Organometallics 2000, 19,

1670Ϫ1676. The third complex is stabilized by a tpa-type li-

gand.^[6c]

C3/5), 122.1 (BAr-C4), 121.8 (Py_a-C3/5), 70.4 (NCH₂Py_b), 67.6

(NCH₂Py_a) ppm. (The signal for Py_a-C3/5 is obscured by one of

the other signals). ESI-MS (CH₃CN): 425 [M Ϫ BPh₄]^ϩ, 393 [M

Ϫ O₂Ϫ BPh₄]^ϩ, (467 [?]^{ϩ [22]}).

[8]

N,NЈ-Dimethyl-2,11-diaza[3,3](2,6)pyridinophane

ϭ 3,11-di-

methyl-3,11,17,18-tetraazatricyclo[11.3.1.1^5,9]octadeca-1(17),

5(18),6,8,13,15-hexaene.

(Hydroperoxy)(hydroxy)[N,N,N-tris(2-pyridylmethyl-κN)-

[9] [9a]

H. Kelm, H. J. Kruger, Eur. J. Inorg. Chem. 1998,

amine-κN]rhodium(III

)

Tetraphenylborate (25BPh₄): Complex

[9b]

1381Ϫ1385.

T. Sciarone, J. Hoogboom, P. P. J. Schlebos, P.

24BPh₄was exposed to a N₂atmosphere saturated with water for

1

H. M. Budzelaar, R. de Gelder, J. M. M. Smits, A. W. Gal,

3 days. 25BPh₄was obtained in Ͼ 90% yield, as determined by H

[9c]

Eur. J. Inorg. Chem. 2002, 457Ϫ464.

S. Plentz Meneghetti,

NMR spectroscopy. ¹H NMR (200 MHz, CD₃CN, 300 K): δ ϭ

P. J. Lutz, J. Kress, Organometallics 2001, 20, 5050Ϫ5055.

3

8.76 (d, J_H,Hϭ 5.9 Hz, 1 H, Py_a-H6), 8.70 (d, J_H,Hϭ 5.7 Hz, 2

[10] [10a]

H. Sakaba, C. Kabuto, H. Horino, M. Arai, Bull. Chem.

3

4

H, Py_b-H6), 7.86 (dt, J_H,Hϭ 7.8, J_H,Hϭ 1.6 Hz, 2 H, Py_b-H4),

[10b]

Soc. Jpn. 1990, 63, 1822Ϫ1824.

H. Kelm, H. J. Kruger,

3

4

Inorg. Chem. 1996, 35, 3533Ϫ3540. ^[10c]W. O. Koch, V. Schune-

7.69 (dt, J_H,Hϭ 7.8, J_H,Hϭ 1.7 Hz, 1 H, Py_a-H4), 7.5Ϫ7.3 (m,

5 H, Py_b-H3 and Py-H5), 7.28 (m, 8 H, BAr-H2), 7.11 (d, ³J_H,Hϭ

mann, M. Gerdan, A. X. Trautwein, H. J. Kruger, Chem. Eur.

3

[10d]

7.8 Hz, 1 H, Py_a-H3), 6.99 (t, J_H,Hϭ 7.3 Hz, 8 H, BAr-H3), 6.83

J. 1998, 4(7), 1255Ϫ1265.

W. O. Koch, V. Schunemann,

3

2

M. Gerdan, A. X. Trautwein, H. J. Kruger, Chem. Eur. J. 1998,

(t, J_H,Hϭ 7.0 Hz, 4 H, BAr-H4), 5.35 (d[AB], J_H,Hϭ 15.5 Hz, 2

H, NCH₂Py_b), 4.75 (m, 4 H, NCH₂Py_band NCH₂Py_a) ppm. ESI-

MS (CH₃CN): 443 [M Ϫ BPh₄]^ϩ, 425 [M Ϫ H₂O Ϫ BPh₄]^ϩ, 410

[M Ϫ HO₂Ϫ BPh₄]^ϩ, 393 [M Ϫ OH Ϫ O₂H Ϫ BPh₄]^ϩ, 300 [M Ϫ

CH₂C₅H₄N Ϫ O₂H Ϫ H₂O Ϫ BPh₄]^ϩ.

[10e]

4(4), 686Ϫ691.

H. J. Krüger, Chem. Ber. 1995, 128,

531Ϫ539. ^[10f]W. O. Koch, H. J. Kruger, Angew. Chem. Int. Ed.

Engl. 1995, 34 (23/24), 2671Ϫ2674.

[11]

[12]

Samples as prepared required the reported reaction time for

full conversion. The different reaction times found for different

complexes could reflect differences in reactivity and/or differ-

ences in particle size distribution.

Acknowledgments

This work was supported by the Netherlands Organization for

Scientific Research (NWO-CW). We thank Johnson Matthey Ltd.

O_βand C_β(O2 and C2) are positioned above and below the

O1ϪMϪC1 plane: the displacement of O2 from this plane is

ϩ

˚

ϩ0.51 A in 8aA and Ϫ0.47 A in 8aB , versus ϩ0.49 A in the

1086

Eur. J. Inorg. Chem. 2003, 1072Ϫ1087

3-Metalla-1,2-dioxolanes and Their Reactivity

FULL PAPER

H. Büning, J. Altman, H. Zorbas, W. Beck, J.

[23]

[23a]

˚

3-platina-1,2-dioxolane 1. The displacement of C2 is Ϫ0.26 A

See e.g.:

ϩ

in 8aA^ϩand ϩ0.29 A in 8aB , versus Ϫ0.29 in the 3-platina-

Inorg. Biochem. 1999, 75(4), 269Ϫ279. ^[23b]K. Tajima, S. Oka,

T. Edo, S. Miyake, H. Mano, K. Mukai, H. Sakurai, K. Ishizu,

J. Chem. Soc., Chem. Commun. 1995, (15), 1507Ϫ1508. ^[23c]P.

N. Balasubramanian, E. S. Schmidt, T. C. Bruice, J. Am. Chem.

Soc. 1987, 109(25), 7865Ϫ7873.

˚

dioxolane.

[13]

[14]

This range is based on OϪO distances in 48 crystal structures

containing a MϪOϪOϪC fragment (M ϭ any metal); 4 out-

liers were not taken into account.

This range is based on OϪC distances in 48 crystal structures

containing a MϪOϪOϪC fragment (M ϭ any metal); 9 out-

liers were not taken into account.

[24]

[25]

R. Cramer, Inorg. Synth. 1990, 28, 86Ϫ88.

G. Anderegg, F. Wenk, Helv. Chim. Acta 1967, 50(243),

2330Ϫ2332.

[15]

[16]

[26]

Bzbpa ϭ N-benzyl-N,N-bis(2-pyridylmethyl)amine.

B. de Bruin, J. A. W. Verhagen, C. H. J. Schouten, A. W. Gal,

D. Feichtinger, D. A. Plattner, Chem. Eur. J. 2001, 7(2),

416Ϫ422.

H. Nagao, N. Komeda, M. Mukaida, M. Suzuki, K. Tanaka,

Inorg. Chem. 1996, 35, 6809Ϫ6815.

[27] [27a]

F. Bottino, M. De Grazia, P. Finocchario, F. R. Fronczek,

A. Mamo, S. Pappalardo, J. Org. Chem. 1988, 53, 3521Ϫ3529.

[17]

[18]

For some examples see: ^[17a]J. C. M. Ritter, R. G. Bergman, J.

[27b]

H. J. Krüger, personal communication.

[17b]

Am. Chem. Soc. 1997, 119, 2580Ϫ2581.

K. J. Del Rossi,

[28]

[29]

[30]

´

J. L. Herde, J. C. Lambert, C. V. Senoff, Inorg. Synth. 1974,

X. X. Zhang, B. B. Wayland, J. Organomet. Chem. 1995, 504,

15, 18Ϫ20.

47Ϫ56.

M. Brookhart, B. Grant, A. F. Volpe Jr., Organometallics 1992,

Space group before and after transformation: C2/c. Cell dimen-

11, 3920Ϫ3922.

sions before transformation: a ϭ 35.8688(5), b ϭ 10.7328(2),

P. T. Beurskens, G. Beurskens, M. Strumpel, C. E. Nordman,

in: Patterson and Pattersons (Eds.: J. P. Glusker, B. K. Pat-

terson, M. Rossi) Clarendon Press, Oxford, 1987, 356Ϫ367.

DIRDIF-96. A computer program system for crystal structure

determination by Patterson methods and direct methods ap-

plied to difference structure factors: P. T. Beurskens, G. Beur-

3

˚

c ϭ 24.2609(4) A, β ϭ 116.666(1)°, V ϭ 8346.4(2) A . Cell

dimensions after transformation:

a ϭ 36.0362(2), b ϭ

˚

10.7760(1), c ϭ 24.2975(2) A, β ϭ 116.3883(4)°, V ϭ 8452.2(2)

[31]

3

˚

A (see Table 5).

[19]

[20]

A. N. J. Blok, P. H. M. Budzelaar, M. Krom, A. W. Gal, paper

to be published.

´

skens, W. P. Bosman, R. de Gelder, S. Garcıa-Granda, R. O.

Yields and reaction times highly depend on the presence of

(small amounts of) water and protonation of the counterion,

which both influence the acidity of the solution.

Gould, R. Israe¨l, J. M. M. Smits, Crystallography Laboratory,

University of Nijmegen, The Netherlands, 1996.

A. L. Spek, Acta Crystallogr., Sect. A 1990, 46, C-34.

PLATON-93. Program for display and analysis of crystal and

molecular structures: A. L. Spek, University of Utrecht, The

Netherlands, 1995.

Immersion Lamp TQ 150 of Heraeus Noblelight GmbH;

power consumption: 150 W. The experimental setup is available

as Supporting Information.

[32]

[33]

[21] [21a]

B. R. Flynn, L. Vaska, J. Am. Chem. Soc. 1973, 95(15),

5081Ϫ5083. ^[21b]T. Yoshida, D. L. Thorn, T. Okano, J. A. Ibers,

[21c]

S. Otsuka, J. Am. Chem. Soc. 1979, 101(15), 4212Ϫ4221.

S. F. Hossain, K. M. Nicholas, C. L. Teas, R. E. Davis, J.

Chem. Soc., Chem. Commun. 1981, 268Ϫ269.

[34]

[22]

The ESI-MS spectrum also shows a peak at m/z ϭ 467, but

1

since both the H NMR and ¹³C NMR spectra (measured at

233 K) do not show any peaks that could stem from a second

product, we have no explanation for the origin of this peak.

Received July 23, 2002

[I02410]

Eur. J. Inorg. Chem. 2003, 1072Ϫ1087

1087

Article Doi

3-metalla-1,2-dioxolanes and their reactivity

DOI: 10.1002/ejic.200390139

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