Building Blocks (build + block)

Distribution by Scientific Domains
Distribution within Chemistry


Selected Abstracts


Engineering Nanoparticle Cluster Arrays for Bacterial Biosensing: The Role of the Building Block in Multiscale SERS Substrates

ADVANCED FUNCTIONAL MATERIALS, Issue 16 2010
Linglu Yang
Abstract Noble metal nanoparticle cluster arrays (NCAs) are a novel class of engineered substrates for surface enhanced Raman spectroscopy (SERS), in which the noble metal nanoparticles interact on multiple length scales to create a multiscale E-field cascade enhancement. In this work the role of the building block for the NCA performance is quantified. Periodic NCAs with constant cluster diameter (D = 200 nm) but variable nanoparticle diameter (d) and intercluster separation (,) were assembled on glass and their optical response and SERS enhancement were systematically characterized as a function of D, ,, and d. An increase of d from 40 to 80 nm and simultaneous decrease of , from 200 to 50 nm led to an improvement of the ensemble averaged SERS enhancement factor by a factor of up to ,8. The coefficient of variation (cv) of the enhancement factors (G) is significantly lower for the d = 80 nm NCAs than for the d = 40 nm and d = 60 nm NCAs. Optimized (D = 200 nm, , = 50 nm, d = 80 nm) NCAs show the overall highest signal reproducibility of all investigated NCAs and random nanoparticle substrates and achieve effective single cell detection sensitivity. [source]


A Thermosensitive and Biodegradable Physical Gel with Chemically Crosslinked Nanogels as the Building Block

MACROMOLECULAR RAPID COMMUNICATIONS, Issue 9 2008
Zigang Yang
Abstract A triblock copolymer, poly(ethylene glycol),poly(propylene glycol),poly(ethylene glycol) was end-capped by acryloyl groups using a biodegradable oligolactide as spacer, and such biodegradable amphiphilic macromers could form micelles in water. A nanogel was prepared via polymerizing macromers in a micelle, and a macroscopic physical gelation was found upon heating a concentrated aqueous nanogel suspension. Such a sol,gel transition with a chemically crosslinked nanogel as the building block was thermoreversible. While the hydrogel affords a promising injectable biomaterial; this research reveals new physics of the thermogelling mechanism of amphiphilic block copolymers. [source]


ChemInform Abstract: Synthesis of 3,4-Dihydroxythiophene-2-carboxylate and Uses as Building Block for Efficient Synthesis of 3,4-Alkylenedioxythiophene (ADOT) Derivatives.

CHEMINFORM, Issue 39 2009
Kyukwan Zong
Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source]


ChemInform Abstract: The Unexpected Versatility of P4S3 as a Building Block in Polymeric Copper Halide Networks: 2,3-P, 1,2,3-P and all-P Coordination.

CHEMINFORM, Issue 7 2008
Andreas Biegerl
Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source]


2, 6-Bis[3-N,N-dimethylamino-1-oxopropen-1-yl]pyridine as a Building Block in Heterocyclic Synthesis: Synthesis of 2,2,:6,,2,,-Terpyridines and 2,6-Bis[pyrazolyl, isoxazolyl, diazepinyl, pyrazolo[5,1-c]pyrimidinyl and pyrazolo-[4,3-d]pyridazinyl]pyridines.

CHEMINFORM, Issue 7 2005
Abu Zeid Abd El Baset Hassanien
Abstract For Abstract see ChemInform Abstract in Full Text. [source]


A Novel Approach to Erythrinan Alkaloids by Utilizing Substituted Biphenyl as Building Block.

CHEMINFORM, Issue 30 2004
Yoshizumi Yasui
Abstract For Abstract see ChemInform Abstract in Full Text. [source]


ChemInform Abstract: Asymmetric Synthesis of Tetrahydroquinoline Derivative, a Building Block of Martinellines, via Intramolecular Allylic Amination Using 9-PBN.

CHEMINFORM, Issue 20 2002
Yasumasa Hamada
Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source]


ChemInform Abstract: Synthesis, Structural, and Optical Characterization of a New Europium(II) Tin Selenide, Eu8(Sn4Se14)(Se3)2 with a (Sn4Se14)12- Building Block.

CHEMINFORM, Issue 48 2001
Carl R. Evenson IV
Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source]


Water as a Building Block in Solid-State Acetonitrile,Pyrogallol[4]arene Assemblies: Structural Investigations

CHEMISTRY - A EUROPEAN JOURNAL, Issue 29 2007
Scott
Abstract Under various conditions, water molecules dramatically affect a number of solid-state C -alkylpyrogallol[4]arene assemblies. In the absence of water, hydrogen-bonded hexameric capsules are formed for the C -butyl, pentyl, hexyl, and heptyl pyrogallol[4]arenes. Introduction of water to acetonitrile solutions containing C -propyl,C -octylpyrogallol[4]arenes resulted in the formation of markedly different bilayer structures and the structural identification of two new dimer-type motifs. [source]


The First Homochiral Diamond-Like Coordination Polymer Containing Cubane Cluster (Cu4I4) as Connecting Node and Cinchonine as Donor-Acceptor (or Push-Pull Electronic Effect) Building Block

CHINESE JOURNAL OF CHEMISTRY, Issue 10 2007
Guo-Xi WANG
Abstract The reaction of CuI with cinchonine (an organic donor-acceptor chromophore) afforded a homochiral 3D diamondoid network [Cu4I4(cinchonine)2]n (1) containing a cubane cluster (Cu4I4) as a connecting node. This is the first homochiral coordination polymer with diamondoid nets containing a cluster as a connecting note. Its thermal stability and solid state optical properties such as fluorescence, circular dichroism and second-harmonic generation response were also reported. [source]


Preparation of Optically Active ,-Amino[3]ferrocenophanes , Building Blocks for Chelate Ligands in Asymmetric Catalysis

EUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 23 2003
Patrick Liptau
Treatment of 1,1,-diacetylferrocene (4) with dimethylamine and TiCl4 yielded the unsaturated dimethylamino-substituted [3]ferrocenophane product 5. Its catalytic hydrogenation gave the corresponding saturated [3]ferrocenophane system 6 (trans/cis , 7:1). The rac -[3]ferrocenophane amine 6 was partially resolved (to ca. 80% ee) by means of L - or D - O,O, -dibenzoyltartrate salt formation. Treatment of 4 with the pure (R)- or (S)-methyl(1-phenylethyl)amine (8)/TiCl4 gave the corresponding optically active unsaturated [3]ferrocenophane amines (R)-(+)- 9 and (S)-(,)- 9, respectively. Their catalytic hydrogenation again proceeded trans -selectively, giving the corresponding saturated diastereomeric [3]ferrocenophane amines (1R,3R,5R)- 10a and (1S,3S,5R)- 10b [starting from (R)- 9], their enantiomers ent - 10a and ent - 10b were obtained from (S)- 9, but with a poor asymmetric induction (10a/10b < 2:1). Quaternization of 6 (CH3I) followed by amine exchange using (R)- or (S)-methyl(1-phenylethyl)amine (8), respectively, proceeded with overall retention. Subsequent chromatographic separation gave the pure diastereoisomers (1R,3R,5R)- 10a and (1S,3S,5R)- 10b [from (R)- 8, ent - 10a and ent - 10b from (S)- 8] in > 60% yield. Subsequently, the benzylic (1-phenylethyl) auxiliary was removed from the nitrogen atom by catalytic hydrogenolysis to yield the enantiomerically pure (> 98%) ([3]ferrocenophanyl)methylamines (1R,3R)- 11 and (1S,3S)- 11, respectively, which were converted into the corresponding dimethylamino-substituted [3]ferrocenophanes (1R,3R)- 6 and (1S,3S)- 6. Each enantiomer from the following enantiomeric pairs was isolated in its pure form and characterized by X-ray diffraction: (R)- 9/(S)- 9; (1R,3R,5R)- 10a/(1S,3S,5S)- 10a; (1R,3R,5S)- 10b/(1S,3S,5R)- 10b; (1R,3R)- 11/(1S,3S)- 11. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003) [source]


Anthraquinones as Artificial DNA Building Blocks

EUROPEAN JOURNAL OF ORGANIC CHEMISTRY, Issue 13 2008
Nicolas Bouquin
Abstract Synthesis and properties of oligodeoxynucleotides containing anthraquinone-derived building blocks with flexible linkers are described. Starting from the 1,4-, 1,5-, 1,8- and 2,6-dihydroxyanthraquinone isomers, the corresponding phosphoramidites were prepared and incorporated into oligonucleotides. The site of linker attachment was found to be of critical importance for hybrid stability. Whereas the 2,6-isomer led to a significant stabilization, all other isomers had a negative effect on the stability of the duplex. Spectroscopic studies showed that the anthraquinones behave as fluorescence quenchers. Models of anthraquinone-modified double-stranded hybrids are proposed. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008) [source]


Converting Core Compounds into Building Blocks: The Concept of Regiochemically Exhaustive Functionalization

EUROPEAN JOURNAL OF ORGANIC CHEMISTRY, Issue 10 2005
Elena Marzi
Abstract In a model study, 3-fluorophenol and 3-fluoropyridine were converted into the each time four possible carboxylic acids by passing through the corresponding organometallic intermediates. As an attempt to generalize the findings reveals, a restricted set of principles and methods suffices to cope with all standard scenarios. The most valuable and versatile tools for the regiochemically exhaustive functionalization of a great variety of substrate patterns are the optionally site-selective metalation (either by reagent/substrate matching or by peripheral coordination control), the use of activating or congesting protective groups and the basicity gradient-driven heavy halogen migration (followed by halogen/metal permutation). (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005) [source]


Gold Nanoparticles Stabilized by Acetylene-Functionalized Multidentate Thioether Ligands: Building Blocks for Nanoparticle Superstructures

ADVANCED FUNCTIONAL MATERIALS, Issue 21 2009
Torsten Peterle
Abstract Aiming at the formation of inorganic/organic hybrid gold nanoparticle superstructures, the design and synthesis of acetylene-monofunctionalized multidentate thioether ligands and their ability to stabilize gold nanoparticles are presented. Rather monodisperse gold particles with diameters of about 1,nm are obtained, which are coated by a small number of ligands, each comprising a silyl-protected acetylene. The acetylene is attached at the end of a rigid ethynylene-phenylene unit of variable length, leading to functionalized gold nanoparticles carrying acetylenes at different distances from the nanoparticle surface. These particles are interlinked by diacetylene formation and are investigated by transmission electron microscopy and UV/vis spectroscopy, revealing the formation of nanoparticle aggregates and small superstructures such as dimers or trimers while the nanoparticles themselves retain their integrity. The interparticle distance in small nanoparticle superstructures reflects the ethynylene-phenylene spacer length corroborating the wet chemical interlinking as the origin of these organic/inorganic hybrid structures. [source]


Tuning the Amphiphilicity of Building Blocks: Controlled Self-Assembly and Disassembly for Functional Supramolecular Materials,

ADVANCED MATERIALS, Issue 28 2009
Yapei Wang
Abstract Amphiphilicity is one of the molecular bases for self-assembly. By tuning the amphiphilicity of building blocks, controllable self-assembly can be realized. This article reviews different routes for tuning amphiphilicity and discusses different possibilities for self-assembly and disassembly in a controlled manner. In general, this includes irreversible and reversible routes. The irreversible routes concern irreversible reactions taking place on the building blocks and changing their molecular amphiphilicity. The building blocks are then able to self-assemble to form different supramolecular structures, but cannot remain stable upon loss of amphiphilicity. Compared to the irreversible routes, the reversible routes are more attractive due to the good control over the assembly and disassembly of the supramolecular structure formed via tuning of the amphiphilicity. These routes involve reversible chemical reactions and supramolecular approaches, and different external stimuli can be used to trigger reversible changes of amphiphilicity, including light, redox, pH, and enzymes. It is anticipated that this line of research can lead to the fabrication of new functional supramolecular assemblies and materials. [source]


Interpersonal Expectations as the Building Blocks of Social Cognition: An Interdependence Theory Perspective

PERSONAL RELATIONSHIPS, Issue 1 2002
John G. Holmes
In this paper I use interdependence theory as an analytic framework for depicting the logically interconnected network of expectations that determines social interaction. The framework focuses on expectations about a partner's goals (B) relevant to particular interdependence situations (S), and suggests that expectations about these two elements define the social situation that activates a person's own goals (A). Together, these elements determine interaction behavior (I). This SABI framework is complementary to Mischel and Shoda's (1995) CAPS theory of personality in its logic. It depicts a person's interpersonal dispositions as having profiles or signatures dependent on both the expected features of situations and the expected dispositions of partners. A taxonomic theory for classifying both situations and the functionally relevant goals of interaction partners is outlined. Research on attachment theory and trust is used to illustrate the model. Finally, I suggest that people's expectations about partners' prosocial motivations,their perceived responsiveness toward the self,play an imperial role in social cognition, and, further, that complex SABI models can be seen as detailing a set of security operations that serve as a program for social action. SABI models detail the set of mechanisms that constitute the basic survival kit of interpersonal relations. [source]


Probing the Building Blocks of Eumelanins Using Scanning Electron Microscopy

PIGMENT CELL & MELANOMA RESEARCH, Issue 3 2000
J. BRIAN NOFSINGER
Scanning electron microscopy (SEM) is used to examine the structure of natural and synthetic melanins. Eumelanin from Sepia officinalis and synthetic eumelanin are found to be structurally dissimilar. The natural sample has a significant structural order with subunits that have a lateral dimension of ,15 nm. The synthetic samples, on the other hand, appear to be amorphous solids. These results lend support for the existence of fundamental structural units proposed from the analyses of wide-angle X-ray diffraction measurements and previous mass-spectrometry results. These findings also provide insight into the disparate photophysical behavior of Sepia and synthetic eumelanin. [source]


Novel Large Aluminophosphite Cage Unit as the Building Blocks to Form a Framework Structure Containing Multidimensional 12-Ring Channels.

CHEMINFORM, Issue 44 2007
Ailing Lu
Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF. [source]


Design of a New Family of Inorganic Compounds Ae2F2SnX3 (Ae: Sr, Ba; X: S, Se) Using Rock Salt and Fluorite 2D Building Blocks.

CHEMINFORM, Issue 15 2006
Houria Kabbour
Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF. [source]


Pyrazoles as Building Blocks in Heterocyclic Synthesis: Synthesis of Some New Substituted 1-Triazinylpyrazolo[3,4-d]pyrimidine and 1-Triazinylpyrazolo[3,4-b]pyridine Derivatives.

CHEMINFORM, Issue 50 2005
A.-F. A. Harb
No abstract is available for this article. [source]


Enaminones as Building Blocks in Heterocyclic Synthesis: New Syntheses of Nicotinic Acid and Thienopyridine Derivatives.

CHEMINFORM, Issue 44 2004
Mervat Mohammed Abdelkhalik
Abstract For Abstract see ChemInform Abstract in Full Text. [source]


4-Aryl(benzyl)amino-4-heteroarylbut-1-enes as Building Blocks in Heterocyclic Synthesis.

CHEMINFORM, Issue 30 2004
Part 4.
Abstract For Abstract see ChemInform Abstract in Full Text. [source]


5H-Oxazol-4-ones as Building Blocks for Asymmetric Synthesis of ,-Hydroxycarboxylic Acid Derivatives.

CHEMINFORM, Issue 23 2004
Barry M. Trost
Abstract For Abstract see ChemInform Abstract in Full Text. [source]


Novel O-Glycosyl Amino Acid Mimetics as Building Blocks for O-Glycopeptides Act as Inhibitors of Galactosidases.

CHEMINFORM, Issue 17 2004
Lars Kroeger
Abstract For Abstract see ChemInform Abstract in Full Text. [source]


Metal-Chelating Amino Acids as Building Blocks for Synthetic Receptors Sensing Metal Ions and Histidine-Tagged Proteins.

CHEMINFORM, Issue 9 2004
Silke Hutschenreiter
No abstract is available for this article. [source]


Enaminones as Building Blocks in Organic Synthesis: Synthesis of New Polyfunctional Pyridines, Condensed Pyridines, and Penta Substituted Benzene.

CHEMINFORM, Issue 10 2003
F. A. Abu-Shanab
Abstract For Abstract see ChemInform Abstract in Full Text. [source]


Synthesis of Sugar Azido or Amino Esters and Their Use as Building Blocks for the Preparation of Saccharide Nucleosides.

CHEMINFORM, Issue 2 2003
Juan Xie
No abstract is available for this article. [source]


ChemInform Abstract: Cyclic Oxonium Ylides: Building Blocks for Iterative Synthesis of Polycyclic Ethers.

CHEMINFORM, Issue 30 2002
Fredrik P. Marmsaeter
Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source]


ChemInform Abstract: Enaminones as Building Blocks in Heterocyclic Synthesis: A New One-Pot Synthesis of Polyfunctional Substituted Pyridines.

CHEMINFORM, Issue 9 2002
Samia Michel Agamy
Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source]


Pyrazino[2.3- g]quinoxaline-Bridged Indole-Based Building Blocks: Design, Synthesis, Anion-Binding Properties, and Phosphate-Directed Assembly in the Solid State

CHEMISTRY - A EUROPEAN JOURNAL, Issue 15 2010
Ting Wang
Abstract Strategies for exploring anionic templates to direct sophisticated supramolecular assembly have attracted attention. Herein, a series of new anion receptors 1,3 containing two indole-based binding sites bridged by linking spacer pyrazino[2.3- g]quinoxaline (PQ) have been rationally designed and prepared from the precursors 2,3-diindol-3,-yl quinoxaline (DIQ) and 5,6-dihydrodiindolo[3,2- a:2,,3,- c]phenazine (DIPZ). X-ray analyses showed a self-connected network and dimeric packing through hydrogen bonding and ,,, stacking interaction in the solid state in the structures of 1 and 2, respectively. All three receptors exhibited a series of prominent absorption bands from the expanded ,,system. The indole-based expanded receptors were found to strongly and selectively bind F,, AcO,, and H2PO4, among the tested anions (F,, Cl,, Br,, AcO,, H2PO4,, HSO4,, NO3,, and ClO4,), and operated as efficient colorimetric sensors for naked-eye detection of fluoride anions in DMSO. These tailored building blocks captured two anions located at far-spaced binding sites, and adopted noninterfering anion-binding processes to guarantee the anion-binding affinity, topology, and dimensionality. Solid-state studies elucidated that the neutral 1,3 interacted with the tetrahedral dihydrogen phosphate anion in proper proportions and designed topologies, thus leading to the formation of a series of multidimensional networks by self-assembly in the solid state. The observations showed a well-characterized phosphate-directed assembly of multidimensional metal-free coordination polymers in the solid state, in which the formed phosphate aggregates, including dimer encapsulated in an indole-mediated hydrogen-bonded pocket and an infinite chain, behaved as anionic templates to direct the self-assembly. However, no evidence proved the presence of such phosphate-directed infinite coordination polymers in solution. [source]