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Furthermore, because of the considerable increase in the radius of the metal ion, as well as the increased oxophilicity of the
metal compared to all other metal complexes containing this
type of ligand, three bridging SiO units link the two metal centers (unsymmetrically). One of the yttrium atoms (Yl) achieves
coordinative saturation by coordination to an oxygen atom in
the ligand framework (021 ; Fig. 2). This type of framework
Fig. 2. Simplified representation of the coordination spheres of the yttrium atoms
to emphasize the structural features of 4. The framrivork oxygen atom 0 2 1 acts as
a donor atom and completes the coordination sphere of Y I .
coordination is unknown for any of the known metal complexes
of sesquisiloxanes, not even for any of the other lanthanoid
siloxane cornplexe~.~'~
The distances from the yttrium center to
the terminal [2.117(8)-2.123(9)
and bridging oxygen atoms
[2.239(9)-2.422(7) A] lie within the expected range.17c1The Y
(021) distance of 2.509(9) corresponds to a typical donor
bond (cf. 2.374(20)-2.462(21) A in [Y(OSiR,),(THF),] .
(THF), R = C,H,17C1).
The Si-0-Si bridging oxygen atoms can act as Lewis bases in
zeolite systems as well.[*] The binuclear complex units 4 are
loosely packed in the solid state. Four crystallographically independent solvent molecules (toluene) are located in the resulting
channels. The size of these solvent channels leads to a considerable disorder of the toluene molecules and explains the facile
diffusion of the solvent out of the crystals even at low temperatures.
Organometallic compounds react preferentially with partially
dehydroxylated silica surfaces, that is with [Si(OH),] centers as
opposed to [SiOSi] sites, towards which they usually behave
indifferently.14d1The yttrium complex 4 shows, for the first time,
the coordination of [SiOSi] sites to an extremely oxophilic, electropositive metal center. This may permit interesting analogies
with the structural chemistry of metal-doped zeolites. For example, in investigations of Ga-exchanged zeolites by I R spectroscopy altered lattice vibrations are observed.[3'. 91 which
should correspond to a change in the catalytic properties. Furthermore, the attachment of neutral silicones of low molecular
weight such as (RSiO,,,), (R = iPr. tBu)"'] onto coordinatively
unsaturated organolanthanoid compounds indicates the possibility of supporting a catalyst following the example in
Scheme 1.
Experimental Procedure
In a glovehox (M. B. BrdUn) amides 2 and an equimolar quantity of 1 were weighed
into a 100-mL round-bottomed flask. Roughly 40 mL of T H F was added by condensation under high vacuum. The mixture was stirred for 1 h at 0 "C then allowed
to warm to 25 C. In the reaction of the yttrium amide a clear solution was obtained
immediately, in the reaction of the neodymium amide only after 30 h. After ca. 40 h
the solvent and the liberated amine were removed under vacuum ( I mbar). The
colorless or light blue residue was dried for 3 h under vacuum ( l o - ' mhar). The
residues are very soluble in n-pentane. Quantiative yields. 3a: Starting from 0.58 g
(0.92 mrnoi) 2a, 0.81 g (0.93 mmol) 1; light blue crystals; correct C,H.Si analysis
(for two THF/Nd: no N): IR: i'[cm-l] =1246 m. 1109 vs, 1088 (sh) vs. 1049 (sh)
s. 998 s. 929 m. 875 w. 846 w, 525 m. 514 m. 3b: Starting from 0.59g (1.04 mmol)
:c) VCH Verlugsp~~.s.sellsc~~ufi
n?hH.D-69451 W~~mheitn.
2b. 0.90 g (1.03mmol) 1; colorless crystals; m.p. 235 'C; correct C.H.N.Si analysis
=1244m. 1111 vs. 1 0 8 7 ~ s1051
(sh)s. 1009
m. 954 m. 926 m. 914 m. 886 m, 841 (sh) wp, 773 w. 519 m. 506 m. 483 m, 466 w.
C,,I H ) NMR (400 MHr. C,D,. 25 C). d
N M R (400 MHz, C,D,, 25 'C): 6
25 .C): 6 = 196.9.
(400 MHz. C,D,.
22.2-30.2 (complex pattern):
65.64. -64.61,
"Y N M R
Received: November 25, 1993
Revised version: February 5 , 1994 [Z 6512 lE]
German version: Anpeu. C'/irtn. 1994. l06. 1338
[ I ] F. T. Edelmann. Angmr. Ctwii. 1992, f04.600: .4ng?w. C/ t . €d €q/.
1992, 32, 586.
[2] a) F. J. Feher. T. A. Budzichowski. K. J. Weller, J Ant. C ' / i m / . So(. 1989. 111,
7288; h) F. J. Feher. S. L. Gonzales. J. M. Ziller. Inorg. Chenr. 1988, 27, 3440:
c) F. J. Feher. J. F. Walrer. i h d 1990. 29, 1604: d) T. A. Budzichowski. S. T.
Chacon. M. H. Chisholm. F. J. Feher, W. Streib. J. Am. Clieni. So(. 1991. f 13.
689; e) F. J. Feher, T. A. Budzichowski, J. W. Ziller. biorg. C'heni. 1992, 31.
5100; f ) G. Calzaferri. Nuchr. Clwm. 7i.r.h. Luh. 1992. 40. 1106.
[3] a) M. Brurzone in Firnrluinentul and Teho/ogicul Aspects of Orgnrio-/-E/rr?irnr
Chrniritr! (Eds.: T. J. Marks. I. L Fragali). Reidel. Dordrecht, 1985; h) W,
Holderich, M. Hesse. F. Niiumann. Angew. Chein. 1988. /IN). 232; Angol
Chem. h i t . 6 1 . En,?/. 1988.27. 226: c) S. L. Suih. Cheni. Re),.1993. Y3, 803: d) T.
Baba. R. Koide. Y. Ono. J. Clion. Soc. C/ieni. Cnnimuif. 1991. 691.
[4] Synthesis of oligosesquisiloxanes: a) J. F. Brown. Jr., L. H. Vogt. J r . . J. A ~ I .
Chrni. So<. 1965, 87, 4313: b) F J. Feher. T. A. Budzichowski. R. L. Blanski.
K. J. Weller. J. W. Ziller. O , g r r n n ~ i / ~ ~ t n
/ / ~ ~10,
s 2526; c) F. J. fisher. D A .
Newman, J. F. Walzer. J. An?. Ch~vn.Soc. 1989. If 1, 1741 : d) T. W. Hambley.
T. Maschmeyer. A. F Masters. Appl. Orgunonxv Clwn. 1992. 6. 253:
e ) G . K. 1. Magomedov, E. A. Chernyshev. L. V. Morozova, A. S. Frenkel.
B. V. Molchanov. S Y. Kochev, S A. Sigachev. A I. Shrodov. E. V. Bulycheva.
Mrlu1loor.g. Khiiii. 1992. 3, 151 ; Orpurlonlet. C h i ? . L,SSR fEngl!.sh [runs.,
1992. 3. XI
(51 P. S. Coan. L. G. Hubert-Pfalzgrat K. G. Caulton. h r g . Cliem. 1992, 31.
161 Growth, selection. and mounting of the crystals was curried out in a glove box
with an integrated polarization microscope and capillary sealing apparatus. 4
crystallized from toluene at -35'C in the triclinic space group Pf with
( I =1647.4(9). h = 2064.2(9), c = 2300.4(38) pm. a = 83.35(4). /r =71.83(4).
7 = 89.50(3)'. T = - 80 f 3 C . 2 = 2. V=7379 x 106 pm3,p = I 2 8 9 gcm-'.
F(000) = 3008. Mo,, radiation. Enraf-Nonius CAD4 diffractometer. w-scans.
max. 50s. lO634measured reflections ( 2 - iH < 30'). /1(-15:15). k ( 0 ' 2 0 ) .
I( - 21 2 1 ) . 8625 independant reflections of which 6156 with I > 3.0 ~ ( 1Mere
used for refinement; correction of intensity (30% decomposition). no correction for absorption (11 = 9.9 c m - ' ) . R = Cl'Fol lFLll);~lFol
= 0.079:
R, = [Xir(lFu] l ~ l ) ' ~ ~ ~ r l F
~ 2 ]residual
' ~ z electron driisity +0.80:
-0.98 e, A?. Further details of the crystal structure investigation may he
obtained from the Fachinformationszentrum Karlsruhe, D-76344 EggensteinLeopoldshafen ( F R G ) , on quoting the depository nuinher CSD-58155.
[7] a) P. S. Gradeff, K. Yunlu. A. Gleizes. J. Galy. Polvherlron 1989. 8. 1001;
b) W. J. Evans. T. A. tilibarri. J. W. Ziller. Orgunofwrullrt~~1991. (0, 134;
c) M. J. McCeary, P. S. Coan. K. Folting, W. E. Streib. K. G. Caulton. Inorg.
Clicin. 1991. 30, 1723.
[XI F. Liebau, Srrrrrfirml Chewnsfry of Siliu/fe.\, Springer, Berlin. 1985
[Y] D. H. Dompas, W. J. Mortier. 0. C. H. Kenter. M. J. G. Janssen. J. P. Verduijn.
J. Cotal. 19Y1, f29. 19.
[lo] a) E. Wiberg. W. Simmler. Z. Anorg. Allg. C h m . 1955,283. 330: b) R. Gewald,
U. Scheim. K. Ruhlinann. H. Goesman. D. Fenske. J Orgunofner.C/i<w.1993.
450. 73.
David B. Amabilino, Peter R. Ashton,
Anatoli S. Reder, Neil Spencer, and J. Fraser Stoddart*
The appearance. toward the end of last year. of a remarkable
paper in a special issue of the New Journal nf'Chemistry, edited by
Sauvage, has drawn attention to the fact that, as long ago as 1960,
[*] Prof. J. F. Stoddart. Dr. D. €3. Amahilino, P. R. Ashton, Dr. A. S. Reder.
Dr. N. Spencer
School of Chemistry, University of Birmingham
Edgbaston. GB-Birmingham B15 2TT (UK)
Telefax: lnt. code + (21)414-3531
[*'IThis work was supported in the tiK by the Science and Engineering Research
0570-0X33!94;f212-1286 d 10.00+ .25i0
Angms. Chen,.
In[. Ed. Engl. 1994, 33. N o . 12
van Gulick[’] had likened the well-known symbol of the International Olympics (Fig. l top)[’] to a pentacatenane, for which he
had gone as far as to suggest the trivial name olympiadane.
ca. 20°C
Fig. 1. The symbol of the International Olympics (top) and the structure of
olympiadane (bottom)
Here, we describe the self-assembly (Scheme 1) and the characterization (Figs. 4-6) of the first molecular compound consisting of a linear
offive interlocked rings. We propose to
call this [Slcatenane (Fig. 1 bottom) olympiadane.
Our first effortsL4I at making a [5]catenane culminated in a
two-step self-assembly route (Fig. 2), which produced a [4]catenane and a whiff (< 0.5 %) of a [5]catenane, which was only
characterized by mass spectrometry. The reason for the reluctance of the [4]catenane to accept the addition of a fifth ring is
enigmatic. Perhaps its templated formation is hindered by a
a - 1 2 ~ ~ ~
negative intramolecular allosteric effect. Whatever the reason, it
Scheme 1. The two-step template-directed synthesis of, firstly. the [3]catenane 44PF, from 1, 2-2PF6, and 3, and secondly, the [4]catenane 7-8PF6 and the [5]catewas clear that we needed to modify the recognition characterisnane 8-l2PF6 from 4-4PF6. 5-2PF6. and 6. The chemical cartoons are defined as
tics of the macrocyclic ether component. Since derivatives of
follows: p-phenylene rings: small blue rectangles; bipyridinium units: large blue
1.5-dihydroxynaphthalene are bound[’] within the receptor site
rectangles; 1,5-dioxynaphthalene rings: red rectangles.
of cyclobis(paraquat-p-phenylene)much more strongly than
the analogous hydroquinone derivatives, we decided to
temperature and atmospheric pressure afforded[’] a [3]catenane
replace the hydroquinone residues in the “failed” tris-pas well as a [2]catenane, an outcome which boded well for the
phenylene[5l]crown-l5 with 1,5-dioxynaphthalene units. Here,
self-assembly of a [Slcatenane under the same conditions. Next,
we describe how this modification improves dramatically the
templating features of the macrocyclic
polyether component and enables the
two-steD self-assembly, at ambient tempfrufurc and atmospheric pressure, of a
[5]catenane, which has been characterized conclusively by mass spectrometry
(LSI-MS) and variable-temperature
‘H N M R (400 MHz) spectroscopy.
trisnaphtho[ 571crown-15
TNP57C15 1 was prepared using a procedurer6]similar to that employed previo ~ s l y [ ~inI the preparation of tris-pphenylene[5l]crown-15. Reaction of 1
with two equivalents of 1.1’-[1,4-phenylenebis(methy1ene)lbis - 4,4 - bipyridinium
bis(hexaflu0rophosphate) (5-2 PF,) and
Fig. 2 . The structure of the [4]catenane (solid-line drawing) comprising two tris-p-phenylene[51]crown-l5macro1,4-bis(bromomethyl)benzene (6) in
cycles, and the cyclophanes, cyclobis(paraquat-p-phenylene) and cyclobis(paraquat-4.4-biphenylene).The
[5]catenane (solid- plus dotted-line drawing) contains an add~tionalcyclobis(paraquat-p-phenylene) macrocycle.
dimethylformamide (DMF) a t ambient
Arigebi. C/irni. Inr. Ed. Engl. 1994. 33, N o . I 2
(Q VCH Verlugsgesellschaft mhH, 0 - 6 9 4 j l Weinheim, 1994
0570-0833;9411212-1287 3 t0.00+ , 2 5 9
treatment of 2-2PF6 with equimolar amounts of 3 in the presence of an excess of 1 afforded['] the [3]catenane 4-4PF6
(Scheme I), albeit in a rather low yield.'91 The [3]catenane was
then treated with an excess of S-2PF6 and 6 at ambient temperature and atmospheric pressure. After just four days, the reaction
mixture was subjected to column chromatography on silica gel.
yielding, after counterion exchange, the unchanged [3]catenane
4-4 PF, (45 %), the intermediate [4]catenane 7-8 PF, (3 1 %). and
the [5]catenane 8-12 PF, (5 %), all beautiful violet-colored compounds (Fig. 3).
Fig. 4. The high-mass region of the positive-ion LSI mass spectrum of S-lZPF,.
showing the sequential loss of hexafluorophosphate counterions, as s e l l as the
step\*ise Loss of the two smaller tetracationic cyclophdnes and one of the macrocyclic polyethers
Fig. 3. The violet bands of the
[4]catenane 7-8PF, and the [5]catenane 812PF, after column chromatography of
the reaction mixture with M e 0 H ; 2 ~
NH,CI(aq):MeNOi ( 7 : 2 : 1 ) on silica gel
for 24 h. Nore that the unchanged
[.l]catsnane 4-4PF, has already been eluted from the column and is contained in
the tmo conical flasks.
The positive-ion FAB"'] and LSI mass spectra" 'I of 4-4PF,,
7-8 PF,, and 8-1 2PF6 show similar fragmentation patterns to
those previously reportedr4I for the analagous [3]-, [4]-. and
[5]catenanes, self-assembled from the appropriate components
with tris-p-phenylene[51]crown-l5as the template. In addition
to the sequential loss of PF; ions, there is also a stepwise loss
(Scheme 2) of macrocycles from the parent catenanes. Figure 4
5073 3978
Irel. 40
Scheme 2. Fragmentation sequence in the LSI mass spectrum of8-12 PF,. The large
red rectangle represents the macrocyclic polyether 1, the small blue rectangle, cyclobis(paraquat-p-phenylene) tetrakis(hexafluoroph0sphate). and the large blue
rectangle. cyc~obis-(pardquat-4.4'-biphen~~ene)
The masses given correspond to the peaks observed in the mass spectrum of 812PF,.
shows the high-mass region of the positive-ion LSI mass spectrum
of 8-12 PF,. A comparison of the theoretical and observed isotopic distributions in the [ M 2PF,]+ ion of8-12PF6 is shown
in Figure 5. By the use of peak matching at high resolution, and
Fig. 5. A comparison of the theoretical isotopic distribution (top) for the
- ?PF,]+ ion of the [Slcatenane 8-12PF, and its high-resolution LSI mass
spectrum (bottom).
with CsI as a reference, the most abundant peak of this ion.
which corresponds to '2C22,'3C,'H2,6160,,'9F6014N123tP
was observed at nziz 5073.3978, a value that is within 5 ppm of
the calculated mass.
The structure[l2]of the [5]catenane 8-12PF6 was confirmed
by variable-temperature 'H NMR spectroscopy.['31At ambient
temperature, the 400 MHz ' H N M R spectrum of 8-12PF6 recorded in CD,CN shows well-resolved resonances at 6 = 5.53,
6.19, 7.72. 1.95, and 8.58 arising from the protons associated
with the cyclobis(paraquat-4,4'-biphenylene)component, while
all the other resonances are broadened by exchange processes.
When the solution is warmed to 70°C (Fig. 6 ) . the four resonances for the nonequivalent protons in the two cyclobis(paraquat-p-phenylene) components become well resolved at 6 =, 7.94, and 8.58 as a result of relatively rapid movements
and reorientations of the naphthalene rings in the macrocyclic
polyether components out of and into the receptive cavities of
these two smaller cyclophanes. Despite this observation. the reso-
'Little Blue'
'Big Blue'
nane 7-8PF, display similar multiple temperature dependencies
in their 'H NMR spectra.
The self-assembly['61 of olympiadane from eight components
in two steps has been made possible as a result of programming
sufficient molecular recognition into the constituent molecular
components.[' 'I Reaching olympiadane-a structure some four
nanometers in length when fully contracted-is symbolic in relation to developing the concept of self-assembly in chemical synthesis. When we can self-assemble a high molecular weight, moiiodisperse polymer, for example a polycatenane," *I with muximum
efficiency, complete selectivity, and prescribed "it?f;7rimtion" rontent, then the molecular self-assembly procedure will be a finely
tuned and honed one. That is our ultimate goal.
Experimental Procedure
- 6
Fig. 6. The partial ' H NMR spectra (400 MHz. CD,CN) of the [Slcatenane 8-8PF6
recorded at 70 C and 0 C The assignments of all the well-resolved signals at 0 C
have been confirmed by a two-dimensional homonuclear shift correlation experiment (COSY45). Thc spectrum obtained at 7 0 - C reflects the averaged D,, symmetry of the molccule.
nances arising from the protons attached to the naphthalene rings
remain broadened on account of the presumably larger limiting
chemical shift differences associated with their resonances compared to those of the cyclophanes. Cooling the solution down to
0 "C results in a spectrum, wherein two sets of resonances are
observed for each set of equivalent protons in the cyclobis(paraquat-p-phenylene) component. This doubling of the number of signals for the smaller cyclophanes is a result of the locally
C,,,:symmetric 1.5-dioxynaphthalene units. which reside in their
cavities and impose lower symmetries upon them. The "freezing" of the 1.5-dioxynaphthalene units inside the smaller cyclophanes is indicated by the emergence of resonances in the
' H N M R spectrum at 6 = 2.10 (broad doublet for H-4/8), 5.82
(triplet for H-3;'7). and 6.10 (doublet for H-216) arising from the
naphthalene protons. The signals for the remaining two 1,5-dioxynaphthalene units in the polyether components remain broad,
as these groups presumably oscillate between the interior and
exterior of the larger tetracationic cyclophane. A AG:-value of
14.5 kcalmol-' (k 0.2 kcalmol-'), corresponding to the reorganization of the smaller cyclophanes with respect to the included
1 .5-dioxynaphthalene units, can be c a l c ~ l a t e d ~from
' ~ ] the k,value of 369 s- at the coalescence temperature (T, = + 37 'C)
for the doublets centered on 6 = 8.42 and 8.84 (0 'C, A>*=
166 Hz). which arise from the r-CH protons of the smaller cyclophane. A similar treatment of the coalescing doublets centered
on 6 = 6.97 and 7.07 (Av = 41 Hz) for the p-CH protons in the
smaller cyclophanes affords a AGT-value of 14.7 kcal mol-'
( k 0 . 2 kcalmol-') from a k , of 92 s-' at +23 "C. This common
free energy barrier of approximately 14.6 kcalmol- can be regarded as the one to be surmounted for the bound 1,5-dioxynaphthalene unit to be dislodged['51from the centers of the
smaller cyclophanes. The [3]catenane 4-4PF6 and the [4]cate-
1 : A solution of 1,5-bis[2-[2-[2-[2-(1-naphthoxy-5-hydroxy)ethoxy]erhoxy]ethoxyJethoxylnaphthalene (2.03 g. 2.55 mmol) in dry D M F (100mL) was added to 21
stirred suspension ofCs,CO, (19.39 g. 61.05 mmol) and CsOTs (1.98 g. 6.88 mmol)
in dry D M F (200 mL) under nitrogen. and the temperature raised to 50 C. After 1 h
a solution of the tetraethyleneglycol bistosylate (1.39 g. 2.77 mmol) in dry D M F
(100 mL) was then added during 1 h. and the temperature raised to 80 C. Stirring
and heating were continued for 4 d. The reaction mixture was then filtered. and the
residue washed with D M F (100 m L ) and EtOAc (100 mL). The solvent was removed under vacuum. and the residue was partitioned between CH,CI, (700 inL)
and H,O (250mLj. The CH2CII phase was extracted once more with H,O
(250 m L ) . after which the organic solution was dried (MgSO,) and concentrated
under vacuum to afford a residue which was purified by column chromatography
EtOAc (9. I)] t o yield 1
white solid (0.99 g. 40%. m.p. X 1
-ion FAB-MS: n : z = 954 for [MI'; 'H NMR (CDCI,). 6 = 3.64
3.74 (m. 24H). 3.89 (t. J = 5 Hr, 12Hj. 4.17 (t. J = 5 Hr. 12H). 6.72 (d.
J = 8.5 Hz, 6H), 7.28 (t. J = X.5 Hz. 6H). 7.84 (d, J = 8.5 HI. 6H): "C NMR
(CDC1,):6 =,70.X.,1146.,154.4. Whenthesame
reaction procedure &as repeated with 1 .I l-bis(l-naphthoxy-5-hydroxy)-3.6.9-trioxaundecane and 1.5-bis[2-[2-[2-[2-(toluene-p-sulfonyl)-ethoxy]etli~~~y]ethoxy~ethoxylnaphthalene as starting materials. a 35% yield of 1 was obtained.
4-4PF6: 2-2PF6 (340mg. 0.44mniolj. 3 (152mg. 0.45mmol). end I (1.023 g,
1.07 mmol) were combined as solids. and a dry mixture of MeCN (22 mL). D M F
(1 mL), and CH2C12 (1 mL) was added. The suspension was allowed to stir at
ambient temperature for IOd, whereupon it was filtered. and the solvent was removed i n Yacuo yielding a purple solid. Column chromatography [SiOz: MeOH,
2~ NH,CI(aq):MeNO, (7:2: I)]. concentration in vacuo of the eluent containing
the product. followed by solubilization of the residue in an H,O:Me,CO mixture.
and precipitation by addition of aqueous NH,PF, solution afforded 4-4PF, as 'I
violet solid (83 mg, 6%. m.p. 109-111 "C) after filtration: positiv-ion FAB-MS
n.1: = 3016. 2871. 2062. 1917. and 1772 for [ M - PF,]'.
[ M - 2PFJ'.
[ M - I - P F , ] + . [ M - 1-2PF,]'.and[iM-l
(CD,CN): b = 3.69-3.74 (m. 48H). 3.75- 3.X1 (m. 24H). 3.82--3.88 (m. 24H). 5.51
JkR = 8 Hz. SH), 8.42 (d. J = 7 Hz. 8H): "C N M R (CD,COCD,): d = 65.6. 68.5.
70.5. 71.4. 71.5. 105.8. 114.2, 125.4. 125.9. 126.4, 128.7. 131.2. 134 5. 141.5. 144.7.
145.0, 154.0. See also ref. [9].
8-12PF,: 5-2PF, (58.4mg. 0.083 mmol), 6 (24.2 mg. 0.092mmol). and 4-4PF,
(62.9 mg. 0.020 mmol) were dissolved in dry D M F (6 mL). and the solution was
stirred for 2 d at room temperature and atmospheric pressure. Then. further quantities of 5-2PF6 (60.2 mg. 0.085 mmol) and 6 (25.5 mg, 0.096 mmol) were added to
the reaction mixture. which was stirred for an extra 2 d. The reaction w a s worked
up as described above for 4-8PF6, except that column chromatography was performed using a gradient elution [SiO,: MeOH;2M NH,CI(aq):MeNO, (7:2: 1 ) ini(12: 10:7:1)].
tially, increased slowly to 2~ NH.CI(aq):DMF:MeOH;MeNO,
Counterions were exchanged by repeated precipitation from aqueous NH,PF,:
Me,CO mixtures, followed by thorough washing with water to remove all traces 01
ammonium salts. 4-4PF, was recovered from the column and was purified b>
crystalliration from CH,CI,'EtiO (28.2 mg, 45%). Pure 7-8PF, was isolated 21s it
violet solid (26.3 mg. 31%. m.p. ~ 2 5 0 - C )UV:VIS
(MeCN. 25 C ) :
transfer) = 531 nm. e = 2190 niol-' dm3cin-': LSI-MS: m:z = 41 18. 3973. 382X.
3699. and 3554 for [ M - PF,]+. [M - 2PFJ'. [ M - 3PF6]+,[M - 4PF,Ji. and
[M --5PFJ+.
respectively: ' H NMR (CD,CN, 70 C): 6 = 3.60-4.00 (m.96H).
5.55 (s, 8H). 5.68 (s. 8H). 6.00-6.20 (br. m. 18H), 6.32 (d. J = 8 Hr. 6H). 6.47 (d.
J = 8 Hz. 6Hj. 6.61 (t. J = X Hz. 6H). 6.70-6.85 (br. m , 8Hj, 7.16 7.20 (m. XH).
7.70 (d. JAH= 8 Hz, 8H). 7.92-7.99 (m. 16H). 8.45-8.55 (m, XH). 8 . 6 8 ~8.76
(m. 8Hj. Pure 8-l2PF6 was isolated as a violet solid (5.1 mg. 5%. m.p.
>250'C): UV'VIS (MeCN, 25-C): &,a.
(charge transfer) = 534 nm. i; =
2640 mol ' dm'cni- I : LS1-MS: PI?:: = 5072. 4928, 4783. and 4673 for
[ M - 2PF61+. [k-3PFJ'.
[ M - 4 P F 6 ] + . and [ M - S P F , ] ' . respectively;
' H N M R (CD,CN, 70 C): 6 = 3.60-4.10 (m, 96H). 5.58 (s, XH). 5.68 (s. 16H).
5.95-6.25 (br. m. 24H). 6.89 (d. J = 7 Hz. 8H). 7.17 (d. J = 7 Hz. 16H). 7.75 (d.
(d. J = 7 Hz. 16H). (The remaining 12H belong to one set of protons attached to the
naphthalene rings The resonances of these protons are broadened into the baseline
by exchange processes.)
Received: January 18. 1994 [Z6627IE]
German version: Angeiv. Chem. 1994. 106. 1316
[ l ] The trivial name olympiadane has been proposed for the pentacatenane which
resembles the symbol of the International Olympics. See N.van Gulick. Nrn.
J Cirem. 1993.17.619 and the preface to this paper by D . M. Walba on p. 618.
The special issue (Ed.: J.-P. Sauvage) of the Nen. Journal of Chemirtr.v published in 0ctober;November 1993 on "Topology in Molecular Chemistry"
contains many excellent papers relating to catenanes.
[2] It has been pointed out (A. Nickon, E. F. Silversmith. Ougunie Chemistry: The
Nunie Gume, Pergamon. New York, 1987. p. 160) that the coat of arms of the
Ciba Foundation displays a [5]catenane with its rings portrayed slightly differently than the symbol of the International Olympics. It is noted that although
"neither of these concatenated emblems has chemical significance". . . "both
symbol? promote universal brotherhood among the five continents-the former in athletics and the latter in education and knowledge."
[3] A single macrocyclization afforded a series of catenanes containing three. four.
five. six. and seYen rings, in which one large ring was encircled by two. three.
four. five and six small rings. respectively. The structure of these catenanes is
different from the linear ones described in this communication. See C. 0.
Dietrich-Buchecker. J. Guilhem. A,-K. KhCmiss. J.-P. Kintzinger. C. Pascard,
JLP. Sauvage. Angeii~Chem. 1987. 99. 711: Angcn. Cheni. Inr. Ed. Engl. 1987,
26.661: J.-P. Sauvage. Ace. Chem. Re.!. 1990.23. 319: F. Bitsch. C. 0. DietrichBuchecker, A.-K. Khemiss. J.-P. Sauvage. A. Van Dorsselear. J Am. Chrni.
So<. 1991.113.4023:C. Dietrich-Buchecker. J.-P. Sauvage. Bull. Soc. Chim Fv.
1992. 129. 113. Most recently. three rings have been templated around a bicyclic core. See C. 0. Dietrich-Buchecker. B. Frommberger. I Luer. J:P.
Sauvage. F. Vogtle. Angeiv. C/iem. 1993. 105. 1526: A n p i < , Chem. fnr. Ed. EngI.
1993.32. 1434.
D. B. Amabilino, P. R. Ashton. A. S. Reder, N. Spencer. J. F. Stoddart, Angebr.
Chem 1994. 106. 450: Angeii. Chem. Inr. Ed. Engl. 1994. 33. 433.
P. R. Ashton. M. Blower. D. Philp. N. Spencer. J. F. Stoddart, M. S. Tolley.
R. Ballardini, M. Ciano. V. Baizani, M. T. Gandolfi, L. Prodi, C. H. McLean.
,Ves J. Chrni. 1993. i7. 689.
P. R Ashton. C. L. Brown. E. J. T. Chrystal. K. P. Parry. M. Pietraszkiewicz.
N Spencer. J. F. Stoddart. Angeii.. Cheni. 1991. 103. 1058: Angeii.. Chem. fnt.
Ed. EnxI. 1991. SO. 1042.
D. B. Amabilino. J. F. Stoddart. unpublished results.
A minor product of this reaction was shown to be the [2]catenane comprising
a cyclobis(paraquat-4,4'-biphenylene)cyclophaneand one macrocycle 1. The
compound was isolated as a purple solid ( 2 % . m.p. 159-161 -C); positive-ion
FAB-MS: IWJ = 2062. 1916. and 1770 for [ M - PF,]', [ M 2PF,]+, and
[ M - 3PFJ'. respectively; ' H N M R (CD,CNj: 6 = 3.72-3.76 (m. 24H).
3.81-3.86 (m. 12H). 3.97-4.02 (m, 12H). 5.69 (s, XH). 6.43-6.53 (m. 12H).
the [3]catenane. so as to create a cyclic [4]catenane. All these and other possibilities can be discounted on the basis of the spectroscopic data obtained for
8-12 PF, .
(131 The ' H and I 3 t NMR spectra were recorded on a Bruker AMX400 spectrometer operating at 400.13 MHz and at 100.63 MHz. respectively. All chemical
shifts are referenced by means of the residual CHD,COCHD, or CHD2CN
signals to Me,Si.
[14] The values of k, were obtained ( I . 0. Sutherland. Annu. Rrp. N M R Specrrusc.
1971. 4. 71) from the limiting chemical shift differences for exchanging signals
by using the approximate expression k , = n(A~);(2)"*. Rate constants were
employed, along with the observed coalescence temperatures of the doublets
for the a-CH and /j-CH protons (attached to the smaller tetracationic cyclophanes in 8-12PF6j. to calculate the AGc*-values at the coalescence temperatures using the Eyring equation.
[I51 In a highly ordered [2]catenane. in which the crown ether component
(DNP38C10) incorporates two 15dioxynaphthalene units. two processes corresponding to movement of the cyclic polyether through cyclobis(paraquat-pphenylene) were observed: one wjhere the included naphthalene ring is displaced. reorients itself. and then enters the cavity once again [AG: =
15.8 kcalmol-'). and the other where the crown ether circumrotates through
the cavity of the tetracationic cyclophane (ACT = 17.2 kcalmol-'). See
P. R. Ashton. C. L. Brown. E. J. T. Chrystal. T. T. Goodnow. A. E. Kaifer.
K. P. Parry, D. Philp. A . M . 2. Slawin, N . Spencer, J. F. Stoddart.
D. J. Williams. J Chen7. Sot. Clieni. Connnun. 1991. 634.
1161 J. F. Stoddart. Ho.51- Guest lWt~/rcnlurInrrvaction.~.From C/7emirti:v to Biolog).
iCihtr Fuund Sjvnp. 1991, f58, 5-22): J. S. Lindsey. .Vew J Chem. 1991, t j ,
153, G. M. Whitesides. J. P. Mathias. C. T. Seto. Science 1991. 254, 1312; J.
Rebek. Jr. ,Molecu/or Recugnirioti: Chmncal and Biochrmicul ProhlemJ I1
(Spec. Puhl. R. Soc. Ci7em. 1992. 111. 65-73).
(171 JLM. Lehn, Sciencr 1993. 261). 1762.
[IS] D . B. Amabilino. J. F Stoddart. Pure Appl. Cherii. 1993. 65. 2351
81 9
a New Phosphorus-Bridged Copper Cluster**
Dieter Fenske* and Werner Holstein
Cluster complexes can be synthesized by treating halogeno(phosphane) transition metal complexes with silylated phosphanes.I'] For example, reactions of silylphosphanes R,PSiMe,
or RP(SiMe,), (R = organic group) with MCI and M'CI,
6.7X(t.J=8Hz.6H).7.51(d.J=6.5H~.8H).7.56(d.J,,=8H~.8H).7.64(M = Cu. Ag; M' = Zn, Cd) in the presence of phosphane lig(d. J,,, = 8 Hz, 8H). 8.75 (d, J = 6.5 Hz. 8H); 13C N M R (CD,CN): 6 = 65.7,
ands PR, result in a large number of cluster complexes that
68.7, 70.3. 71.2. 71.4. 106.4. 114.0. 126.5. 126.6. 126.7. 128.8. 130.7. 134.3,
contain bridging phosphido and phosphinidene ligands.r2]Sev141.6, 145.5. 147.4. 154.2.
The low solubility of I in acetonitrile makes the self-assembly procedure leaderal examples are summarized in Scheme 1. The steric bulk of
ing to the [3]catenane difficult to perform in an efficient manner.
the organic groups at the bridging P atoms has a stabilizing
FAB-MS (Fast Atom Bombardment Mass Spectrometry) for 4-4PF, was caron the framework of the cluster; however, this also preeffect
ried out on a Kratos MSXORF mass spectrometer (accelerating voltage, 3 kV:
vents the formation of larger units.
resolution. 1000) coupled to a DS90 data system and off-line Sun Workstation
for processing the raw data experiments. The atom gun was an adapted saddlefield source (Ion Tech Limited) operated at ca. 8 keV and a tube current ofca.
2 mA. Krypton was used to provide a primary bedm of atoms. and the samples
were dissolved in a small volume of 3-nitrobenzyl alcohol which had previously
been coated onto a staiiiiess steel probe tip. Spectra were recorded in the
positive-ion mode at a scan speed of 30 s per decade.
For samples 7-8 PF, and 8-12PF, LSI-MS (Liquid Secondary Ion Mass Spectrometry) was carried out on a Kratos Concept 1H mass spectrometer (accelerating voltage. 8 kV: resolution, 1000) coupled to a Sun Sparc Station with
Mach3 software. The samples were dissolved in acetone. and a small volume
(1 - 2 pL) was added to the 3-nitrobenzyl alcohol matrix. Spectra were recorded
in the positive-ion mode at a scan speed of 5 s per decade. We gratefully
acknowledge the assistance of Kratos Analytical, and in particular Dr. M.
Kimber, Dr. H. Wight. and Dr. J. Moncur. in the collection of the mass spectra
for these compounds.
Apart from the linear sequence of macrocycles. several different topological
isomers could be formed in the reaction that self-assembles the [5]catenane
8-12PF6. In particular, we may consider the possibility that an isomeric
[5]catenane is formed where two cyclobis(paraquat-p-phenylene)rings clip onto nnr and the same component 1. Further. it is possible that the same clipping
procedure could occur simultaneously on the other ring 1. yielding both a [6]and a [7]catenane. There is preliminary evidence that. under appropriate conditions. these products are indeed formed. Alternatively. a cyclic dimer of the
tetracationic cyclophane may also form. threading through macrocycles I in
C VCH Vrrlug.~gi~.~ell.~chutt
mhH. 0-69451 Weinlirirn, 1994
We have now investigated analogous reactions of CuCl in the
presence of phosphanes PR, with P(SiMe,), . If these reactions
are carried out in THF, with the exception of PEt, which gave
[*I Prof. Dr. D. Fenske, DipLChem. W. Holstein
lnstitut fur Anorganische Chemie der Universitiit
Engesserstrasse, Geb. Nr. 30.45. D-76128 Karlsruhe (FRG)
Telefax: Int. code (721)661921
[**I This work was supported by the Deutsche Forschungsgemeinschaft (SFB 195)
and the Fonds der Chemischen Industrie.
OS70-OX33~94."212-1290B 10.00f . Z j 0
Angel,' Cfietn. Inr. Ed. Engl. 1994, 33. No. 12
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