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Graphical Abstract (Angew. Chem. Int. Ed. Engl. 15161996)

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A Journal of the
GeselIschaft
Deutscher Chemiker
U i
1994133
15116
International Edition in English
Pages 1523- 1674
COVER PICTURE
The cover picture shows schematically the construction of two isostructural, adamantanoid. spacer-free, metallospherands [Fe,L,] (L = dianion of dialkyl2,5-dialkoxycarbonyl-3,4-dioxo-1.6-hexanedicarboxylate)
formed by self-assembly. An NH:
ion is encapsulated in its center. One Fe" (silver sphere) and three Fe"' ions (golden
spheres) form a regular tetrahedron, whose six edges are bridged by bis(bidentate)
ligands L (charcoal-colored angled rods). The cover picture was produced with the
program POV-Ray on a Silicon Graphics Indigo Workstation by Dr. R. Burdk.
Further details of the synthesis, characterization, and properties of these inclusion
compounds are reported by R. W. Saalfrank et al. on p. 1621ff.
REVIEWS
Contents
Redox transformations between O,/H,O, NJNH, ,
and H + / H , are extremely important biologically
and industrially. Natural enzymes containing one or
more transition metals catalyze these transformations. Functional mimics of enzymes can lead to a
better understanding of the biological mechanisms
of these processes and to the invention of new homogeneous catalysts.
G3
R1/
C\R2
1
( R )-Oxynitrilase
II
+
HCN
2
, 4 1 1 p i . C ' l i m i . I!!/. Ed. Enpl. 1994. 33. No. lS:16
1537-1554
metalloenzymes
NH3
N2
Immobilized enzymes in organic solvents are used in the enantioselective synthesis of
cyanohydrins (3, R' = alkyl. aryl, heteroaryl; R 2 = H, alkyl) from carbonyl compounds ( I ) and hydrogen cyanide (2). Enzymatic kinetic resolution of rac-3 is also
conducted in organic media. Chiral cyanohydrins can thus be prepared in high
optical purities and serve as valuable synthetic building blocks owing to the wide
range of subsequent conversions.
0
J. P. Collman,*
P. S. Wagenknecht,
J. E. Hutchison ......................
Molecular Catalysts for Multielectron Redox Reactions of Small Molecules: The
"Cofacial Metallodiporphyrin" Approach
F. Effenberger* ......................
1555- 1564
Synthesis and Reactions of Optically Active
Cyanohydrins
OH
I
RI,cL,/,
R2
CN
3
C' VCH
K4upspeseilschafi m h H , 0.69451 Weinherm,1994
OS70-~X33194!1jlS-ISrS$ /fl.OfJ+ . 3 : 0
1525
A triad representation and the competition between the x-donor ligands for the available dx symmetry orbitals on the metal can be used to explain the preferred orientations of alkene, alkyne. and alkylidene ligands in tetrahedral complexes. In complexes such as 1 with two strong n donors (Cp and N R ligand), for example. alkenes
point to the weakest n donor (PMe, ligand). With a few simple rules a qualitative
ordering of ligand n-donor bond strengths can be derived and structures can be
rationalized or predicted.
V. C. Gibson * ........................
1565- IS72
Ligands as “Compass Needles”: How
Orientations of Alkene, Alkyne, and
Alkylidene Ligands Reveal n-Bonding
Features in Tetrahedral Transition Metal
Complexes
c3
1
RN
RN
HIGHLIGHTS
The rapid identification of functional molecules that participate in specific
supramolecular interactions is a major problem in the screening of compound
libraries. The binary encoding developed by Still et al. allows the structure assignment of “active” compounds according to a simple encoding scheme, and is independent of the synthetic chemistry employed. The viability of this concept has already
been demonstrated, but the advantages will first be fully realized with libraries of
small organic molecules.
P. Eckes* ...............................
The linear arrangement of the atoms in CO, also occurs, in most cases, in its anionic
analogues NBN3-and CBN4-. as well as in the ions SNS’, PCS-, and PBP3- that
are analogous to CS,. Many of the findings and structures predicted by quantum
chemical calculations have since been confirmed by crystal structure analyses. This
should encourage the synthesis of additional isoelectronic analogues.
T. M. Klapotke ......................
1573- 1575
Binary Coding of Compound Libraries
2575-1576
New Ionic, Isoelectronic Analogues of CO,
and CS,
COMMUNICATIONS
The whole is greater than the sum of its parts-this adage holds for the new replication system composed of 1 and 2, which features a very high affinity between
complementary components. In this system all reactions proceed via complexes,
which minimizes the effects of background reactions. The autocatalysis displayed by
the system is shown to arise solely from template effects. R = -C,H,-C,H,COOC,F, .
M. M. Conn, E. A. Wintner.
J. Rebek, Jr.* .........................
1577-1579
Template Effects in New Self-Replicating
Molecules
Pr
Pr
k
Complementary surfaces and reactive functionalities
are the ingredients of a system that mimics the twostep replication process of DNA. Two separate coupling reactions each give a product that is a template
for the next reaction.
R . J. Pieters, I. Huc,
J. Rebek, Jr.* .........................
1579-1581
Reciprocal Template Effects in a Replication Cycle
Con tenis
Nucleophilic ring opening of cyclic carbonates 1 leads regioselectively to the less
substituted ester 2. Moreover, for molecules with several carbonyl groups the reaction is chemoselective: In a taxol precursor the carbonate group and not one of the
three additional carbonyl groups was attacked; the resulting esters were converted
into taxol analogues that displayed differing cytotoxicities.
I.">[
K. C. Nicolaou,*
E. A. Couladouros.
P. G . Nantermet, J. Renaud,
R. K. Guy,
W. Wrasidlo ...........................
ycni
NuO_ yCn&VCnl
0
1
-
mF
1581 - 1583
Synthesis of C-2 Taxol Analogues
OH O K N U
2
0
K. C. Nicolaou,* R. K. Guy,
E. N. Pitsinos,
W. Wrasidlo ............. . .... . ........ 1583 - 1587
Just as effective and not as toxic, taxol derivative
1 displays antitumor activity comparable to that
of the parent compound. Since 1 is water soluble,
complications that arise in clinical applications
of taxol may be avoided.
H
A Water-Soluble Prodrug of Taxol with
Self-Assembling Properties
6Ac
1
G. A. Downing, C. S. Frampton.
D. D. MacNicol,*
P. R. Mallinson .....................
1587 - 1589
The first versatile coronene-based host is the dodecathioether 1 . The structure of the highly crystalline
1,4-dioxane adduct of 1 was elucidated; it revealed
that the host molecule has the novel C,-symmetric
uuhbarihhauhh conformation.
xq
Trigonal Symmetry as a Host Design Element: Novel Conformation of Dodecakis(3,5-dimethylphenylthio)coronene in its
3.4-Dioxane Clathrate
1,x=s
Up to fourth-generation neutral phosphorus-containing dendrimers are
prepared in good yields in the synthesis outlined here. The only byproducts are NaCl and H,O, and the
products contain highly reactive
functional groups along the periphery. The first-generation dendrimer
is shown on the right.
i3p
N. Launay, A.-M. Caminade.
R. Lahana,
J.-P. Majoral* ___._................__.
1589-1592
S
/I
oypo
NXN/MC
I
M e \ I~ / N
S=P-CI
ct-p=s
c1
I
N
I
Me
S
,N,
A General Synthetic Strategy for Neutral
Phosphorus-Containing Dendrimers
c1
0
&I
CI
Intra- and intermolecular ferromagnetic interactions
characterize the dimeric manganese complexes 1
and 2. This unexpected behavior is attributed to ETI interactions between the phenoxy ligands, to 71-x
interactions within the chains present in the crystal,
and for 2, in addition, to TI-TC interactions between
bromine atoms of neighboring chains. These findings should be useful for the design of molecular
magnetic materials.
[Mn(OC,X,H,),(bpy),]
1, X
=
C1;
2, X
=
Angrii. Chwi?.Irrl. Ed. Enngl. 1994, 33. N o . 15i16
M. Wesolek, D. Meyer,
J. A. Osborn,* A. De Cian,
J. Fischer," A. Derory, P. Legoll,
M . Drillon* ..._._ __ _._ _ ..... ... ...., .. I592 - 1594
2
Ferromagneto-Structural Correlations
in [Mn(OC,X,H,),(bpy)],,
X = CI, Br
Compounds
Br
:(->
VC'H Verltigsgesellsrhuft m h f l , D-69451 Weinhein?, 1994
0570-0833/94~1515-1527.R lfJ.O0+ 2 W
1527
G. Alberti,* F. Marmottini,
S. Murcia-Mascaros,
R. Vivani ...............................
The computer-generated structural
model on the right clearly shows the
interlayer microporosity ( Vmicrop,=
0.12 cm"g- ' ) of the covalently
pillared y-zirconium phosphatediphosphonate. Thus, this type of
compound could be of interest as a
molecular sieve or for shape-selective
catalysis. The pillaring was achieved
by a simple topotactic reaction.
'4)
1594 1597
Preparation and Preliminary Characterization of a Covalently Pillared Zirconium
Phosphate- Diphosphonate with I nterlayer
Microporosi ty
H. Tdkekuma,
S. Takekuma,
Y. Matsubara .........................
Charge-transfer interactions stabilize the 1 :2 complex between C,,, and 7-cyclodextrin (schematic representation shown on the right). Since it is known
that C,,, derivatives inhibit. for instance, the HIV-1
protease, this result is also.important for the understanding of the molecular recognition of C,, by the
hydrophobic pocket of the active site of enzymes.
2. Yoshida,*
A novel mode of linkage of polyhedral
boranes is exhibited in the title anion
1 : The structure of 1 derives formally
from the fusion, with two common
vertices, of an cir~ic.hno-SB,and an
t r r c ~ l z n o - S B , ,subcluster.
,
Anion 1 is
lormed by treatment of unli-B,,H,,
with NaH in T H F followed by reaction with sulfur; i t crystallizes as the
PPh: salt.
T. Jelinek, J. D . Kennedy,*
B. Stibr,
M . Thornton-Pett .................. 1599 . 1601
I597 1599
Molecular Recognition of' C,,,, with
y-Cyclodextrin
Macropolyhedral Boron-Containing Cluster Chemistry: Isolation and C'haracterization of the First Macropolyhedral Thiaborane, the aracho-Type [9,9'-S2B,,H I ,]
Ion
36)
The opposite relative configuration to that observed i n the deuteration of deprotonated sulfoxides of type 2 results from the radical deuteration of sulfinylated
benzyl radicals of type I in the presence of bulky Lewis acids (methylaluminum
diphenoxide).
P. Renaud,* T. Bourquard,
M . Gerster, N . Moufid .......... 1601 . lh03
The substitution pattern determines whether distilbenylazobenzene compounds 1 or
their subsequent products, the dihydrocinnolines 2, are isolated in the cobalt-catalyzcd solvent-free reaction of azo compounds with diphenylacetylene. For several
derivatives ;I photochromic equilibrium exists between the two forms.
G . Halbritter, F. Knoch,
A. Wolski, H. Kisch* ............ 1603 1605
Ph
I
R*
R'
R' = H, CI
R 2 = H , Me
R3 = Me, CI,F
Stereoselective Reactions of Sulfinvlated
Benzyl Radicals: Effects of Solvents and
Lewis Acids
Functionalization o f Aromatic A m Compounds by the Cobalt-Catalyzed, Regioselective Double Addition o f Tolane:
2,6-Distilbenylazobenzenes and
2,3-Dihydrocinnolines
Contents
U. Rosenthal,* A. Ohff, W. Baumann,
tBu
The unexpected result of the reaction of “Cp,Zr”
with di-/eif-butadiyne was the formation of 1, the
smallest possible cyclic cumulene. Other disubstituted butadiynes reacted with “Cp2M” by cleavage,
dimerization. o r dinuclear complex formation.
$’
Cp2Zr
-
tBu
The transition state of the dienone-phenol rearrangement of 1 to 2 is mimicked by
hapten 3. An immune response to 3 yielded an antibody (62C7) which was found to
catalyze the rearrangement efficiently. It was shown that 62C7 does not act as a
simple acid catalyst, but rather selectively stabilizes the charge distribution in the
transition state.
R. Kempe, A. Tillack,
V. V. Burlakov .................___.._
1605-1607
Synthesis and Structure of the Smallest
Cyclic Cumulene; Reaction of 1,3-Diynes
with Zirconocene Complexes
Y. Chen, J.-L. Reymond,*
R . A. Lerner* ..______.__.............
1607- 1609
An Antibody-Catalyzed 1 -2-Rearrangement of Carbon-Carbon Bonds
0
1
2
3
A novel variant of the asymmetric oxidation of prochiral thioethers yields chiral
sulfoxides with selectivities of up to 98 % de. The thioether is first coordinated to an
enantiomerically pure auxiliary and then oxidized In the coordination sphere with
dimethyldioxirane [Eq. (a)]. Smooth decomplexation is achieved with NaI.
I
Ph,
Ru
A P p 7 g\
Ph,
R’
PF;
-
(4
W. A. Schenk,* J. Frisch,
W. Adam,* F. Prechtl ............. 1609-161 1
Oxidation of Metal-Coordinated
Thioethers with Dimethyldioxirane- A New Stereoselective Synthesis of Chiral
Sulfoxides
‘Me
Not only mechanistically interesting but also preparatively attractive- for example,
because of inexpensive starting materials-the olefination of aldehydes such as 1
catalyzed by Lewis acids is described here for the first time. This surprising one-pot
reaction leads to styrene 2.
H.-P. van Schaik,
R.-J. Vijn,
F. Bickelhaupt* .....................
1611 -1612
Acid-Catalyzed Olefination of Benzaldehyde
(4
,Tic,,
A third mode of reactivity for allylsilanes in their
reactions with a,&unsaturated carbonyl compounds has been found in addition to the Sakurai
reaction and the [3 + 21 cycloaddition. Silylmethylcyclobutanes are formed regioselectively via a siliranium ion intermediate (1). The reaction with methyl
propynoate provides bicyclo[2.2.0]hexanes in a onepot conversion.
+
d
R3Si
x
1
A formal role as monoene and also as diene by utilizing the mesityl substituent is
possible for the unstable silene 1. In the absence of scavengers, 1 dimerizes in an
unusual [2+4] reaction to form 2 as soon as it is prepared from (Me,Si),SiC(0H)Mes.
I
Angew. <’/win. In1 Ed. Engl. 1994, 33. N o . 15i16
h
H.-J. Knolker,* G. Baum,
R. Graf ..................................
1612-2615
+
21 CycloaddiLewis Acid Promoted [2
tion of Allylsilanes and Unsaturated Esters:
A Novel Method for Cyclobutane
Construction
C. Krempner, H. Reinke,
H. Oehme* ............................
1615-1618
The Formation and an Unusual Dimerization of 2-Mesityl-1 , I -bis(trimethylsilyl)silene
0 V C H V~rlugsgeseIlsc/iu/imhH, 0-69451 Weinheim, 1994
057O-OX33iY4/1S15-Is?Y$ 10.00+ 2 S 0
1529
Extremely soluble, briefly air-stable, and thermally
more robust than expected are Celv complexes such
as 1 containing the Me,Si-substituted cyclooctatetraene dianion as ligands. The metal atom in these
complexes is sterically well shielded by an organic
shell. The way is now free to investigate the reactivity of this class of compounds.
In a simple one-pot reaction the host-guest compounds 1 (white spheres Fe"'; black = Fe"; gray =
NH: ; angled rods = 2: R = Me, Et) are accessible
in gram quantities by self-assembly. They are the
only fully characterized redox isomers whose cyclic
voltammograms display four quasi-reversible waves
and whose mixed-valent character has been established by Mossbauer spectra. The endohedral complexation of one NH,f ion in 1 has been confirmed
by X-ray crystallography
U. Kilimann, R. Herbst-Irmer,
,,,,,3Me3
D. Stalke,
F. T. Edelmann* ....................
SiMe,
Me,Si
An Efficient Access to Organocerium(1v)
Complexes: Synthesis and Structure of
Bis[1,3,6-tris(trimethylsilyl)cyclooctatetraene]cerium(rv)
"'"SiMe,
Me,Si
1
0
2
Ro R02C
C02R
Agreement between theory and practice: Solid-state N M R studies on organic compounds with CH,CI, CHCI,, and CCI, groups show that residual dipolar coupling
between 35Cl/37C1and I3C nuclei influences the splitting of the signals depending on
the magnetic field strength B. When molecular motions are slow enough to prevent
self-decoupling, signals for C nuclei affected by a single C1 nucleus appear as symmetric doublets at B,> 5 T and as asymmetric triplets at lower fields.
R. W. Saalfrank,* R. Burak,
A. Breit, D. Stalke, R. Herbst-Irmer,
J. Daub. M. Porsch, E. Bill,
M. Miither,
A. X. Trautwein _.__.................
1621 -1623
Mixed-Valence, Tetranuclear Iron Chelate
Complexes as Endoreceptors: Charge
Compensation Through Inclusion of
Cations
S. H. Alarcon, A. C. Olivieri,*
S. A. Carss, R. K . Harris ....... 1624-1625
Effects of 35C1/37C1,'3CResidual Dipolar
Coupling on the Variable-Temperature
I3C CP/MAS NMR Spectra of Solid,
Chlorinated Sodium Acetates
B. R. Peterson,
F. Diederich * ... .... ..... ... ..... . ... . 1625 1628
A new therapeutic approach to treating atherosclerosis? The chiral. D,symmetrical cyclophane 1 is a selective receptor for cholesterol in water
and dissolves the insoluble solid
steroid efficiently through inclusion
complexation. The cavity of 1 with
dimensions of 9 x 13 x 11 8, has the
ideal shape and hydrophobic surface
for encapsulating steroids.
-
Dissolution of Cholesterol in Water by a
Synthetic Receptor
H. L. Anderson, C. Boudon,
E Diederich,* J.-P. Gisselbrecht,
M. Gross,* P. Seiler* ............ 1628-1632
The presence of a transannular bond at a methanobridged 6-6 ring junction in C,, was confirmed
conclusively with an accurate crystal structure of the
title compound 1, thus putting an end to a heated
debate. The length of the 6-6 bond is 1.574(3) A.
'b
k
*~*
* P
;&ab
%4
1
Oxidative addition to the antitumor agent cisplatin
yields the Pt" complex 1 , in which 1.1,3,3-tetramethylthiourea is coordinated to platinum. The
structure was determined primarily by impressive
high-resolution H and 195Pt N M R experiments
and by analysis of the IR spectrum.
1618-1621
1
I
N
, ,\
I
C
I!
U. Bierbach.*
J. Reedijk* ..............................
+
yN\
s
CI-
H3"*,,,,
j
",it
Pt"
\CI
1
CI
#C'
61.61 -Bis(trimethylsilylbutadiynyl)-l.2-dihydro- 1.2-methanofuIlerene[60] : Crystal
Structure at 100 K and Electrochemical
Conversion to a Conducting Polymer
1
1632-1634
An Unusual Route to Potential Platinum
Antitumor Compounds: Synthesis, Reactivity, and Spectroscopic Properties of the
Pt'" Complex ,foc-[PtCl,(NH,),L]Cl
Contents
The reactive cationic 14-electron complex 2 is stabilized by formation of methylbridged binuclear complexes of type 1 and 3. The compounds are highly active
catalysts for the polymerization of ethylene and propylene. As expected for the
dissociation equilibrium shown, neutral alkyl metal compounds in excess act as
inhibitors: thus. the activity of 3 decreases significantly with increasing AiMe,
concentration.
1
2
M. Bochmann,*
S. J. Lancaster ........................
1634-1637
Monomer- Dimer Equilibria in Homo- and
Heterodinuclear Cationic Alkylzirconium
Complexes and Their Role in Polymeriza-
3
D. Buchholz,
D. Astruc* .............................
Only with a second-row transition metal as the
central
atom
can
decamethylmetallocenes
[M(C,Me,)2]+ be fully perrnethylated to give
decaisopropylmetallocenes 1. The corresponding
rhodium complex, M = Rh, was isolated in 5 5 %
yield; in the analogous reaction of the cobalt sandwich complex, a maximum of 14 methyl groups were
introduced.
PF~-
1637- 1639
The First Decaisopropylmetallocene:
One-Pot Synthesis of [Rh(C,iPr,),]PF,
from [Rh(C,Me,),]PF, by Formation of
20 Carbon-Carbon Bonds
1
Two proximate bicyclobutane units are contained in the new hexacycle 3. Their
arrangement facilitates a transannular reaction in the radical addition of thiophenol
to give the cage compound 4. Starting from benzvalene ( l ) ,the route to 3 comprises
only five steps: the first (1 + 2) is a Pauson-Khand reaction.
&
-b
&
W
u
-b
H
a
C
CN
1
SPh
3
2
N
M. Christl,* M . Turk,
E.-M. Peters, K. Peters,
H. G. von Schnering .............. 1639- 1641
Octahydro-l,2,3 : 4,5,6-dimethenopentaIene-2-carbonitrile, the First Derivative of a
Yet-Unknown (CH),, Hydrocarbon
H
4
W. J. Evans,* R . Anwander,
R. J. Doedens, J. W. Ziller ...... 1641 - 1644
Hexane-soluble derivatives of neodymium amide Nd(NMe,), such as 1 or the unsolvated heterometallic
peralkyl compound 2 form in the reaction of MMe,
( M = Al. Ga) with 3. This provides a route to soluble lanthanide complexes with small ligands.
2
The Use of Heterometallic Bridging
Moieties To Generate Tractable
Lanthanide Complexes of Small Ligands
[ N ~ ( ( I I - ~ M ~ ~ ) ( I I - M C ) M M ~ ~ ~ , ( ~ ~ - N 1M ~ , ) ( M M ~ , ) ]
NdGa,{Me,,
2
" ~ ( N M ~ ~ ) , ( L I C I ) J3
Liquid-crystalline behavior over a wide temperature range and reversible phase transitions are observed for the polymer network 1. which is held together by hydrogen
bonds between benzoic acid and pyridyl units.
A.
H2::
HC-C 40
T. Kato,* H. Kihara, U. Kumar,
T.Uryu,
J. M. J. Frechet* ....................
1644- 1645
Liquid-Crystalline Polymer Network Built
by Molecular Self-Assembly through Intermolecular Hydrogen Bonding
0
yn ' o ~ c H 2 k
. , o
N ~
x Nc
....H-0
~ ~ ~ ~ .
> C O O ~ C H & O$-YH
0
CH2
1
Ladder oligomers of various lengths
containing metallomacrocycles as
structural elements (shown on the
right) have been synthesized in a controlled fashion for the first time. The
oligomers possess three, five, or
seven nickel atoms, the polymer at
least nine.
+i
M. Rack,
M . Hanack* ..........................
1646 --I648
Ladder Polymers and Oligomers Based on
Hemiporphyrazine
.&
An unexpected amino acid metabolism is used by a
subspecies of the soil bacterium Strepton7yces violuceoniger to produce the antifungal antibiotic pyridazomycin 1 4 . Feeding studies with isotopically
labeled precursors indicate that 1 is constructed
from ornithine, glycine. and probably oxaloacetate.
, N - N + v
H2N
0
COOH
NH2
1
H. Bockholt, J. M. Beale.
J. Rohr* .................................
1648-1651
Biosynthetic Investigations on Pyridazomycin
A sandwich-like structure. in which planes of closely
packed C,6 molecules are interleaved with layers of
S, rings, is formed by the fullerene-sulfur adduct,
C7h(S8)h(shown on the right). The structure of this
compound has been studied by single-crystal X-ray
diffraction. The results are consistent with a chiral
C,, molecule with D, symmetry.
R. H. Michel. M. M. Kappes,
P. Adelmann,
G. Roth* ...............................
1651-1654
Increased stability towards enzymatic degradation is
observed for oligonucleotides if they contain the
thymidine analogue 1. Its binding ability for complementary RNA is not decreased significantly,
which makes 1 interesting as a building block for
antisense oligonucleotides. Compound 1 can be prepared in a nineteen-step synthesis starting from Dserine.
K.-H. Altmann,* S. M. Freier,
U. Pieles, T. Winkler .............. 1654-1657
Preparation and Structure of C,h(S8)6:
A First Step in the Crystallographic
Investigation of Higher Fullerenes
oy
"vNrH
&O
Synthesis of an Azathymidine and Its
Incorporation into Oligonucleotides
**
HO
1
Pulse chemisorption studies reveal that a subsequent reaction is part of the mechanism of the formation of synthesis gas from CH, and CO,, known since 1928. In the
first step CH, is decomposed on a Rh/AI,O, catalyst into reactive surface carbon C ,
and H,; in the second step C, reacts with CO, to give CO, but it is still not clear
whether this step is also catalyzed by Rh.
N
One monodentate and two bidentate carboxylato ligands link the central Fe" ion in the cation of 1
(shown on the right) with each of the three neighboring Fe" ions. This arrangement results in a complex
with threefold symmetry and weak ferromagnetic
interactions between the iron centers. Such aggregates may be important in the initial stages of ferritin core formation in the absence of dioxygen. Hbpg
= N,N-bis(2-pyridylmethyl)glycine.
[Fe,(bpg),(OZCC,H,),l(C1O,),
1
'(.:I
1657-1660
Active Surface Carbon-A Reactive Intermediate in the Production of Synthesis Gas
from Methane and Carbon Dioxide
S. Menage, H. Fujii, M. P. Hendrich,
L. Que, Jr.* ............................
1660-1662
Carboxylatoiron(I1) Aggregates: A Novel
Fey Complex with Threefold Symmetry
N
Vesicles with concave binding sites on
the surface form when the bowlshaped amphiphile 1 is dispersed in
water. The dimples on the outer surface of these molecular "golf balls"
strongly bind guest molecules (association constant K, = 4 x ~ O ' M - ' ) .
1532
M. F. Mark,
W. F. Maier* ..........................
VCH Verlug~gcs~~ll.schf~rft
inhH, 0-69451 Wcinheini,1994
A . P. H . J. Scheming,
B. de Bruin, M. C. Feiters,*
R. J. M. Nolte* ......................
1662-1663
Molecular Golf Balls: Vesicles from BowlShaped Host Molecules
0570-0833i94j1515-1532 B 10.00f 25i0
Angew. Chern. Int. Ed. En$. 1994, 33. N o . 15/16
Contents
Six q'-0-coordinated SO, ligands are present in the
pinwheel-shaped cation of complex 1. This mode of
coordination was considered unusual. The synthesis
was achieved by oxidation of Ni powder with AsF,
in liquid SO,. An analogous reaction with iron
yielded cic-[Fe(S02),(FAsF,),1.
E. Lork, J. Petersen,
R. Mews* ..............................
1663. 1665
No bonding interactions exist between the three interpenetr'iting framework structures in 1, and all of the
two-dimensional networks are constructed by coordinate Iink'iges these two principles describe the
qtructure of 1 (shown schematically on the right)
Compound 1 was prepared from K,[Cd(CN),]. AgNO,. .ind pyrazine at pH 10.
T. Soma, H. Yuge,
T. Iwamoto* ..........................
1665-1666
Three-Dimensional Interpenetrating Double and Triple Framework Structures in
[Cd(bPy),(A&(CN),I,l
and [Cd(PYrz){Ag,(CN),} {A&(CN),i1
b
[Cdip~i.iLiiie)IAg2(CN),J
(Ag(CY)L)] I
l*+ 3. E. Lyons, D. R.Rasmussen,
A planar tetracoordinate carbon atom in a singlycharged saturated hydrocarbon is found for the first
time. Ah initio calculations at the HF/6-31G* level
predict a planar geometry for the central five-carbon
moiety in the octaplane radical cation (1.'). The
ionization energy of octaplane ( 5 eV) is found to be
remarkably low for a saturated hydrocarbon; indeed. i t is comparable to that of the alkali metals
lithium and sodium.
M. P. McGrath, R . H. Nobes,
L. Radom * ............................
1667- 1668
Octaplane: A Saturated Hydrocarbon with
a Remarkably Low Ionization Energy
Leading to a Cation with a Planar
Tetracoordinate Carbon Atom
l'+
1688
Corrigenda
BOOKS
Cluster Ions
*
C.-Y. Ng, T. Baer, I . Powis
Phase Transfer Catalysis E. V. Dehmlow. S . S. Dehmlow
Phase Transfer Catalysis. Selected Problems and Applications
Fundamentals of Nuclear Magnetic Resonance
Neural Networks for Chemists. An Introduction
*
J. Zupan, J. Gasteiger
. W. R. Moser, D. W. Slocum
B. K . Keppler
Fluorescence Spectroscopy. New Methods and Applications
New Books
Author Index A-83
*
1669
I? Theil ............................................
1669
U . Haeberlen ...................................
1670
G. Schneider, P. Wrede ....................
1671
G. Consiglio .....................................
1671
B. Lippert ........................................
1672
R. NieJner .......................................
1673
Y. Goldberg
J. W. Hennel, J. Klinowski
Homogeneous Transition Metal Catalyzed Reactions
Metal Complexes in Cancer Chemotherapy
-
M . P. Irion .......................................
0. S. Wolfbeis
1674
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