close

Вход

Забыли?

вход по аккаунту

?

Graphical Abstract (Angew. Chem. Int. Ed. Engl. 11995)

код для вставкиСкачать
Gesellschaft
_
_
__
Deutscher Chemiker
_
International Edition in English
1995
341.1
Pages
1- 128
3
~
International Advisory Board
roughly 60 %5 in 1994. Most of these manuscripts
have come ,from Europe, the U S A , and Japan
(see Figs. 1 and 2 ) . The number of review articles
x
c from other countries has always been high, und
m
5a, excellent overviews Iiave contributed strongly to
(3 the reputation of the journal. The growing intera,
U
national character and continued high quality qf
.In
3
Angetvandte Chemie is recognized bj, the GDCh
0
and
encouraged. Last year on urging from the
U
a,
Editorial
Board, the president qf the society invit.E
n ed the respected scientists listed on the previous
3
In
page to yurticipate on an International Advisory
In
t
.-0 Board.
h
-m
u
0
1
Y
U
a,
1
.1
E
n
S
In
C
.-0
1
m
V
._
C
2
5
0
1
c
I
m
.-
z
K
:
0
Fig. 1. The number of communications submitted rose steadily from 1984 to
1993, but those submitted from Germany did not increase as fast as the total
(see also Fig. 2). This is not surprising since the best papers from Germany in
the central fields of Inorganic and Organic Chemistry have always been
submitted to Angewandic Cliemie. The value for 1994 (in red) was not
included in the linear regression calculation.
I
x
C
m
Ea,
2
U
a,
.-
4
1
-
E
n
3
In
In
C
0
.c
m
V
.C
E'
E
8
Fig. 2. The increase I n submissions of communications was particularly
pronounced both from Western Europe and from the USA. Red: values for
1994 (not included in the regression calculation).
These illustrious individuals represent different
regions and research areas. As advisors they wilI
serve as ambassadors and consultants ,for the
journal and should help make Angecoundte
Chemie even more attractive. The masthead will
now provide authors and readers with visible
prooj of the internationality of the ,journal, hut
the name Angewmdte Chemie will continue to
testify to the German origins.
The International Advisory Board and the Editorial Board-the latter of which was joined this
year by Professors F: N . Diederich ( E T H ,
Zurich), R. u/: Hojfmann (University of Marburg), K. Kiihlein (Hoechst AG, Frankfurt), and
-x G. WurfJ' (University o f Diisseldorf)-should
m help the editorial office maintain its successful
5 course.
a,
u
al
0
c
3
0
v
'0
a,
+
*
.-
E
n
2
v)
In
0
.c
m
.-u
c
z
5
0
Prof. Henri Brunner
Head of the Editorial Board
COVER PICTURE
The c o w r pictiire shows the en\,ironment of the Rb-centered R b , octahedron in the
compouiid h a , , R b 7 S b 7(Na = anthracite. R b = blue, Sb = red). The virtually
spherical iso~~irfaces
of the parti;il electron densities are colored according to the
values ol'thc electron localization function (high values are white). They support the
intei-pretation of the Rh-centered Rb, octahedron as Rb-(Rb'),. More about this
unusual anrimonide that was prepared from the elements under inert conditions at
X73 K is ireported by H . G. von Schneriiig et al. on page 103ff.
REVIEWS
With the rapid development of opto-electronic technology, new inaterials are required that show nonlinear optical phenomena and at the same time fulfill a
series of additional criteria such as optical transparency. thermal stability, processability. and ease of
npplication-specific modification. Organometallic
systems. like 1. through their unique characteristics
such ;is diversity ofmetals, oxidation states. ligands.
and geometries. allow fine-tuning of the properties
to be cari-ied o u l . which thus makes them suitable
candidates for device application.
Contents
N. J. Long* ...................................
21-38
Organoinetallic Compounds for Nonlinear
Optics The Search for En-light-enment!
NOz
1
The extremely different structures and properties of the neurotoxins enable them to
interact very specifically with key sites in the nervous system. Neurochemists are
beginning t o deduce the site of action from the neurotoxin structure. These compounds ha\e already proved invaluable in detecting and analyzing the key sites. for
example. in the conduction of nerve impulses within neurons and in their transfer
from cell to cell.
F. Hucho * ....................................
39-50
Toxins as Tools in Neurochemistry
HIGHLIGHTS
Electrophilic addition-so you thought you knew it all! Recent research into the title
reaction shows that a reexamination of well-established mechanisms by means of
modern theoretical. analytical, and synthetic methods can be altogether worthwhile.
For exxnple. A. C. Legon et. al (hgcir. Chetii. It?[.Ed. EngI. 1994, 33, 1512-1 51 3)
recentl) investigated the interactions between ethene and halogens with an F T
microwiiw hpectroineter equipped with B fast-mixing nozzle.
The reaction of arene anions with metal halides is not
only a n elegant approach t o arenemetalates. but
may also Icad to structurally novel complexes, as
Ellis et al. recently found ( A t ~ g e i i ~C. / w m h i t . Ed.
E/ig/. 1994. 33. 1973-1975) in. for instance. the
potassium salt of 1. the first tris(arene)inetal complex with three independent arene ligands.
P
&\
1
R. Herges * ...................................
51 -53
New Findings in the Electrophilic Addition
of Halogens to Olefins
U. Zenneck
*
Mononuclear
plexes
.................................
Tris(arene)-Metal
53- 54
Com-
COMMUNICATIONS
.4single crystal was not needed for the structure determination of radical 1. This is the first time that
the structure of a purely organic molecule having
only sand p electrons and with more than ten atoms
in the unit cell was obtained froin powder X-ray
diffraction data. The structure is in agreement with
that expected from the magnetic properties of I .
Contents
J. Cirujeda, L. E. Ochando.
J. M. Amigo. C. Rovira. J. Rius.
J. Veciana* ....................................
I
0-
1
55-57
Structure Determination from Powder XRay Diffraction Data of a Hydrogen-Bonded Molecular Solid with Competing Ferromagnetic and Antiferromagnetic Interactions: The 2-(3.4-Dihydroxyphenyl)-r-Nitronyl Nitroxide Radical
The first synthetic model for competitive exchange of an organic compound, specifically the exchange of triaminopyriinidine (TAP) between barbituric acid/TAP aggregates in water and highly ordered monolayers of a barbituric acid lipid, were studied
by IR and UVWis spectroscopy. Similar competitive interaction are important in
membranes and cell biology.
T. M. Bohanon, S. Denzinger.
R. Fink. W. Paulus, H. Ringsdorf,*
M.Weck .......................................
58-60
A convergent synthesis not requiring sugar protecting groups yields N-glycopeptides.
The key step is the condensation of unprotected glycosylamines with resin-bound
peptides that have activated carboxyl groups in specified positions. Twenty-three
N-linked glycopeptides such a s 1 and 2 all derived from one peptide motif were
obtained. This approach should facilitate generation of glycopeptide libraries.
D. Vetter.* D . Tumelty,
S. K. Singh. M. A. Gallop* .......... 60-63
G l n ( G a l ) - T y ~ - G l ~ - ~ I ~ - P l i c - 1L e u
Barbituric Acidl'2,4.6-Triaminopyrimidiiie
Aggregates in Water and Their Competitive
Interaction with Monolayers of Barbituric
Acid Lipids at the Gas.--Water Interface
A Versatile Solid-Phase Synthesis of NLinked Glycopeptides
~y~-Gly-Gln(Glc(/~I-~)Glc)-Gly-Phe-L~ii
2
The spiro-S building block 1 is an unusual arrangement of five [TO,] tetrahedra (T = Si. Zn) to give
two three-rings of tetrahedra. This building unit is
the backbone of the partial structure of the tetrahedral framework of the new zincosilicate zeolite 2.
The nonframework components Na K + , and H,O
likewise form a three-dimensional network. which
contributes considerably to the stability of 2.
C. Rohrig, H. Gies* .....................
63-65
A New Zincosilicate Zeolite with NineRing Channels
+,
K , N ~ , , [ S ~ , , Z I ~ , O - ~18
]. H 2 0 2
Up to now cationic hosts were necessary for the
molecular recognition of hydrophilic anions in
water. This task can, however, also be performed with the cage molecule 1 having zero
net charge. The vital design feature is the rigid
separation of substructures of unlike charge,
which enables encapsulation of the guest in the
central cavity
K. Worm. E P. Schmidtchen* ...... 65 -66
Molecular Recognition of Anions by Zwitterionic Host Molecules in Water
~~
At about 460°C indigo ( 1 ) isomerizes to dibenzonaphthyridindione (2) in the gas
G. Haucke.* G. Graness .............. 67-68
phase remarkably smoothly with ring enlargement to incorporate the central C-C
double bond. The transition state was calculated (PM3) and is characterized by the
rupture of the bonds between the carbonyl groups and the central C = C unit.
Thermal Isomerization of Indigo
X. Zhang, J. L. Schindler, T. Hogan,
J. Albritton-Thomas, C. R. Kannewurf,
M. G. Kanatzidis* .......................
68-71
Columnar stacks of discrete Cu,Te, six-membered
rings i n which each copper atom is also coordinated
to ;I Tei chclating ligand are present in the crystals
of 1 (depicted on the right) and in the isomorphous
compound 2. The stacks are held together by
T e . . 'Te interactions: sodium ions are located in interstitiiil sites between the rings. and Ba'+ and Te'ions cocryst:illix lor charge neutralization. Compounds I and 2 are semiconductors with a narrow
band p i p .
i x L t B L i c > t . l 1 3 x , dI
The Novel Copper Polytelluride Salts
NaBa,Cu,Te,, and (Ko,~,,lBa,
Ba,Cu,,,,Te,,:
Discrete ('lusters or Extended Solids'?
( K ~i ,,, l ~ ; l o . , , , ) B ~ , c u ~ . ~ , T ~2 , ,
Na,Ti,CI, is a temperature-dependent magnetic switch. The switching process
( = phase transition) takes places below room temperature and is accompanied by
a drastic decrease in magnetic susceptibility and molar volume. The transition is
attributed to thc formation of [Ti,],' clusters (see diagram) by two-dimensional
Peierl's distortion within [TiCI,,,C12,3]2 layers.
D. J. Hinz, G . Meyer,*
T. Dedecke, W. Urland* ............... 71 -73
Aggregates of fractal dimension were found in the
intermediate gel phases that organize prior to nucleation and crystallization (shown right) of silicalite
from ;I homogeneous reaction mixture. Small- and
wide-angle X-ray scattering studies prove that for
zeolites nucleation may be homogeneous or heterogeneous.
W. H. Dokter, H. F. van Garderen,
T. P. M. Beelen,* R. A. van Santen,
W. Bras .........................................
73 -75
Merely the change of the solvent for the crystallization of the title compound leads to different crystal
moditic'itions In the orthorhombic crystals (from
n-hexane) 't methoxy group i s twisted out of the C,
plme (\ec structure) I n the monoclinic crystals
(from diisopropyl ether) all four methoxy groups lie
in the pldne of the C, rings
H. Bock,* A. Rauschenbach,
C. Niither, Z. Havlas, A. GaLezzotti.
G . Filippini ...................................
76-78
Catalytic decomposition of diazo compound 1,
which is readily available in homochiral form. leads
exclusively to the unsaturated, enantiomerically
pure lactam 2. This chiral C,-building block and its
enantiomer open access to asymmetric pyrrolidinones and pyrrolidines. which are of potential therapeu t ic LI t i li t y .
Na,Ti3C1,: From Isolated Ti2* Ions to
Clusters
[Ti$
+
Homogeneous versus Heterogeneous Zeolite Nucleation
Orthorhombic and Monoclinic 2.3,7,8Tetramethoxythianthrene: Small Structural
Difference- Large Lattice Change
G. Chelucci, A. Saba * .................. 78-79
Ph
:,$+ :,Go
Ph
0
0
I
Me
Mc
1
2
(S)-( +)- and (R)-(-)-I S-Diinethyl-4phenyl-I ,5-dihydro-2H-pyrrol-2-ones by
Carbene Ring Contraction and Decarboxylation of (2 R,3 S)-(-)- and (2 S, 3 R)-( )6-Diazo-3,4-dimethyl-2-phenyloxazepane5.7-diones
+
Contents
J. P. Snyder* ....................................
Where are the electrons in copper complexes with a
formal Cu"' oxidation state? Ah initio calculations
suggest cuprate 1 to contain a d" Cu' metal atom
and the average of one CF; and three CF; groups.
Assignment of oxidation numbers based on consideration of the metal center alone can be misleading.
Elusiveness of Cu"'Complexation; Preference for Trifluoromethyl Oxidation in the
Formation of [Cu'(CF,)J Salts
4
A surprisingly straightforward cyclotetramerization
of tBuC E P in the coordination sphere of an q8-cyclooctatetraene-zirconium complex yields 1.3.5.7tetraphosphabarrelene I . The bicyclic compound is
initially bound to the Zr atom through two P = C
bonds, but can easily be liberated from the complex
by reaction with hexachloroethane.
pq+
P
n
1,3,5,7-TetraphosphabarreIene:A New
Cyclic Phosphaalkyne Tetrainer
B. Kriiutler,* T. Direr. P. Liu,
W. Muhlecker, M. Puchberger,
K. Gruber. C. Kratky * ............_...84-86
B. Kriiutler,* J. Maynollo ........_.__.
87-88
A Highly Symmetric Sixfold Cycloaddition
Product of Fullerene C,,
-
Through light-induced cis-trans isomerization of the hydrophobic azobenzene fragment (see below), the binding of surfactant molecules to hydrophobically modified
poly(acry1amide)s can be switched on and off, which influences phase separation and
gel formation.
8
81-83
Oligomethylene-Bridged Vitamin B , ?
Dimers
In one step and with 26% yield, a sixfold DielsAlder product is formed from buckminsterfullerene
C,, and ?,3-dimethyl-l.3-butadiene.This first direct
synthesis of a highly symmetric, exohedrally sixfold
substituted fullerene addition product is remarkably
simple. The components were heated in orfhodichlorobenzene at roughly 110°C for ten days, and
the product was purified by column chromatography.
0%
P. Binger.* G. Glaser, B. Gabor.
R. Mynott .....................................
1
The reaction of the highly nucleophilic Co' form of
vitamin B,, with 1.o-dibromo-n-alkanes ( ( I ) 2 4)
leads to oligoniethylene-bridged B, dimers in high
yields. Use of 1.4-dibromobutane results in a dimer
(shown schematically on the right), in which the two
cobalamin moieties are tightly packed and coaxially
linked through a tetramethylene chain. which is a
synclinal conformation.
so;
80-81
J. J. Effing, J. C. T. Kwak * ............ 88-90
Photoswitchable Phase Separation in Hydrophobically Modified Poly(acrylamide)/
Surfactant Systems
.so;
so;
so;
I(
P'CH I ~ , ~ / ( ~ ~ ~ huff
, ~ ~t ,d .l H
~ ,~D-094.il
, / / , ~ ~Li?;th+i,
199.1
1 / ~ 7 ~ l - ~ l ~ S 3 ~ ; 4 5 ~ ~ JB l lO.O(J
O I - ~+
l ~.25,'0
~~l,S
A i i g w . Clim.
/ti/.
Ed. EngI. IYY5. 34. N o . I
Site-specific attachment of biological molecules on gold and silicon dioxide surfaces
has been achieved : The surface is modified with the receptor!'hgand pair avidin D/
photobiotin I and exposed to light through a mask in the presence of a protein
solution: binding only occurs in the exposed areas. After unbound material is
removed b y washing. this process can be repeated several times to produce a twodimensional pattern. One of the potential applications of this technique is the patterning of antibodies in a format that can be used in a multi-analyte immunosensor.
Nanostructures through self-assembly: Suitably de-
signed planar cyclic peptides like 1 form cylindrical
diniers in nonpolar organic solvents. These ensembles are good models for the fundamental description of parallel and antiparallel /&sheet structures a s well a s for the design of novel peptide
nanostructures. The analysis of the structural and
thermodynamic aspects of the dimerization process
showed that the hydrogen bonds between the peptide backbones are crucial factors for the stability of
the enseinbles and selective formation of 8-sheet arrangements. Furthermore 1 crystallizes to form a
novel, porous. solid-state object with an amphiphilic
tubular superlattice. which may have potential utility in the molecular inclusion of hydrophilic and hydrophobic substr2itcs.
N-CH:,
H3C''''
O f
H3CHN
N
'33
95-98
1
/$Sheet Peptide Architecture: Measuring
the Relative Stability of Parallel vs. Antiparallel /]-Sheets
The first dendritic polysilane, methyl[tris(permethyIneopentasilyl)]sIlane[(Me,Si),SiSiMe2],SiMe. has been synthesized starting from (Me,Si),SiH and characterized
by crystallography. The dendrimer comprises 27 Si, pathways and consequently
exhibits UV absorption with greatly enhanced intensity over that of simple linear
polysilanes of similar length.
The intermediate metallacycle 1 was isolated from
the reaction of the corresponding (~/~-allyl)palladium complex with deprotonated isobutyronitrile i n THF;TMEDA (TMEDA = N.N.N'.N'-tetramethylethylenediamine) . When CO was passed
over ;I solution of 1 in dichloromethane at room
temperature. the compound underwent spontaneou\. slercoselective reductive elimination to form
the corresponding cyclopropane.
93-95
The Structural and Thermodynamic Basis
for the Formation of Self-Assembled Peptide Nanotubes
K. Kobayashi, J. R . Granja,
M. R. Ghadiri* ...........................
,
CH,
Micron-Scale Patterning of Biological
Molecules
J. R. Granja, R . K . Chadha.
D. E. McRee .................................
&P-z~o
P
91 -93
M. R. Ghadiri,* K. Kobayashi,
F H 3 FH3 0
Z
D. J. Pritchard, H. Morgan.*
J. M. Cooper * .............................
n
MeZN,
,NMe2
Me
98-99
Synthesis and Structure of a Dendritic
Polysilane
H. M. R. Hoffmann,*
A. R . Otte, A. Wilde, S. Menzer,
D. J. Williams ............................
100- 102
fCN
"...
ph ,
J. B. Lambert,* J. L. Pflug,
C. L. Stern ....................................
Ph
Me
1
Isolation and X-Ray Crystal Structure of a
Palladacyclobutane: Insight into the Mechanism of Cyclopropanation
An unusual electron distribution is shown by the ternary antimonide Na,,Rb,Sb,.
since o n l y 3-1 of the 23 valence electrons of the alkali metal atoms are required for
the formation of the Sb3- centers to be expected because of the semiconducting
behavior. The remaining two electrons are localized in the region of a R b center,
which is located inside a Rb, octahedron. The formulation of this center as R b - is
supported for example by the synthesis of the isostructural Na,,Rb,ISb, and by the
results of quantum chemical calculations.
H. G . von Schnering,*
R. H. Cardosa Gil, W. Honle.
A. Burkhardt,* G. Krier,
0. K. Andersen ..........................
Differences in the absorption intensity in the spectral range between 400 and 500 nm,
which the human eye perceives as changes in color, are the reason why solutions of
C,,, show different colors. The results of the experiments described rule out the
formation o f charge transfer complexes or of C,, aggregates.
J. C a t a h , * J. L. Saiz,* J. L. Laynez,
N. Jagerovic, J. Elguero* ........... 105-107
The Stabilization of the RbNa,,Rb,Sb, = Na,,(RbRb,)Sb,
The Colors of C,, Solutions
103-105
Ion in
Content5
Furocoumarin hydroperoxides such as 1 are novel photochemical sources of hydroxyl
radicals; in salmon testes D N A they form the mutagenic oxidation product 8-hydroxy-2’-deoxyguanosine 2 in up to 1.8% yield on UVA irradiation (2 = 350 nm).
W. Adam,* J. Cadet, F. Dall’Acqua,
B. Epe. D. Ramaiah,
C. R . Saha-Moller .__........._........
107- 110
Photosensitized Formation of 8-Hydroxy2’-deoxyguanosine in Salmon Testes D N A
by Furocoumarin Hydroperoxides . A Novel. Intercalating “Photo-Fenton” Reagent
for Oxidative D N A Damage
P
OCH,
HO
2
1
~
A planar W,N, ring showing marked alternation in
the bond lengths (structure shown on the right) is the
distinctive structural element in the trimeric tungsten nitride 1 (R = C(CH,),CF,), which was obtained by reaction of the alkoxide [W,(OR),] with
benzonitrile. When R = SirBuMe,. a complex 15
formed in solution with a central W,O, ring and
terminal nitrido Iigands.
“NW(OR),J
31
M . H . Chisholm.* K . Folting-Streib,
D. B. Tiedtke, F. Lemoigno,
0. Eisenstein* .........................
.. 110-112
&0
0
0
W
&,
i;c“N
W
9
*
N
’S
1
The reactive nitridomolybdenum(vr) fragment 1 is
available from the reaction of [Cp:Mo,CI,] with
azides. Aggregation occurs in different ways depending on the conditions to afford compounds
containing six-membered rings with either localized
or delocalized metal -nitrogen multiple bonds. The
nature and structure of the products indicates that 1
has a nucleophilic nitrido ligand.
Participation of several 14-electron complexes
as intermediates in the [Rh(PH,),CI]-catalyzed
addition of BH, to alkenes is suggested by results of a b initio pseudopotential computations, which also indicate a preference for migration of a hydrogen atom rather than the
BH, group to the C=C bond in the key step.
The calculations also provide a rationale for
the diastereoselectivity of the reaction. The
structure calculated for one of the intermediates is shown on the right.
Solid-state and Solution Structures of
[{NW(OC(CH,),CF,),J ,] and Factors Favoring the Metathesis of C - N and N-W
Triple Bonds in Reactions Involving Organic Nitriles and Ditungsten Hexaalkoxides
W. A. Herrmann,* S. Bogdanovic,
T. Priermeier, R. Poli,*
.I.C. Fettiiiger ............................
122-115
C1---M0SN
c1/
1
Aggregation of Nitrido- Metal Complexes:
The Example of [(~s-C,Me,)Mo(N)Cl,]
A. E. Dorigo,
P. von R. Schleyer* _.........._.......115 - 118
An Ab Initio Investigation of the Rh’-Catalyzed Hydroboration of C=C Bonds: Evidence for Hydrogen Migration in the Key
Step
* Author
to whom correspondence should be addresied
BOOKS
Contents
B. Coriiils .........................................
119
FT-NIR Atlas . M. Buback, H. P. Vogele
W Suridcr ......................................
120
Activated Metals in Organic Synthesis . P. Cintas
P. Knochel .........................................
121
Cluster Chemistry . G. Gonzilez-Morega
Clusters and Colloids G. Schmid
L. H . Gritke .........................................
121
Fritz Haber
-
Chemiker, Nobelpreistrager, Deutscher Jude . D. Stoltzenberg
123
Yew Books
Author Index 125
Keyword Index 124
Preview 126
Документ
Категория
Без категории
Просмотров
0
Размер файла
1 170 Кб
Теги
abstract, int, angel, engl, chem, graphical, 11995
1/--страниц
Пожаловаться на содержимое документа