Search results for "Solid-State"

Synthesis and thermal decomposition studies of homo- and heteroleptic tin(iv) thiolates and dithiocarbamates: molecular precursors for tin sulfides

2002

The syntheses and X-ray structures of novel heteroleptic thiolate/dithiocarbamate derivatives (Et2NCS2)2(RS)2Sn (R = Cy, CH2CF3) have been examined and their thermal decompositions compared with those of selected tin(II) and tin(IV) dithiocarbamates. The heteroleptic species decompose to SnS by initial elimination of RSSR to afford (Et2NCS2)2Sn and subsequent loss of [Et2NC(S)]2S. In contrast, (Et2NCS2)4Sn decomposes via [(Et2NCS2)2SnS]2, whose structure has been determined, and finally to SnS2 by sequential elimination of [Et2NC(S)]2S. The two families of compounds, (R2NCS2)4Sn and (Et2NCS2)2(RS)2Sn, thus provide single-source materials for bulk SnS2 and SnS, respectively, by virtue of the…

ChemInform Abstract: Highlights on Contemporary Recognition and Sensing of Fluoride Anion in Solution and in the Solid State

2013

The fluoride anion has recently gained well deserved attention among the scientific community for its importance in many fields of human activities, but also for concerns on its effect on health and the environment. Although surprisingly overlooked in systematic studies in the past, fluoride has nowadays become a topical target in the field of anion recognition. A multitude of scientific reports are published every year where the establishment of efficient and specific interaction with fluoride is sought in polar and aqueous media. Here, the emphasis is directed to a detailed description of the most interesting contemporary studies in the field, with a particular focus given to those publis…

1973

The mechanism of radiation-induced polymerizations in the solid state has been a subject mostly open to speculation. As radiation usually generates several kinds of active species (radicals and ions) it is difficult to find out, which of these actually causes polymerization. We have developped a method distinguishing between cationic and anionic active centers. Cationic polymerizations are terminated by addition of a base such as sodium alkoxide in a suitable solvent. The alkoxide is incorporated into the polymer as an endgroup. This endgroup is determined analytically after isolation and purification of the polymer. The incorporation of alkoxy endgroups into the polymer is a proof of the o…

Synthesis and photodimerisation of tetrabenzo[ab,f,jk,o][18]annulenes

1999

Abstract The tetrabenzo[ab,f,jk,o][18]annulenes 7a,b, generated in a 5-step synthesis, show photodimerisation and -oligomerisation reactions in the solid state and in solution. The state of aggregation determines the reaction route. Whereas the cyclodimer 8a has a simple cyclobutane structure, the dimer 8b is a highly symmetrical cyclophane.

NMR Solution Conformation of the Proposed Recombin Like Structure D(CCGCGG)2

1997

Long repeated stretches of d(CCG) trinucleotide are the crucial mutation of gen that causes hereditary form of mental retardation (fragile X-syndrome). Moreover, the alternating (CG) dinucleotide is one of the candidates for Z-DNA conformation. Both sequences are part of the hexanucleotide d(CCGCGG)2- d(CCGCGG)2 forms different crystals depending on the crystallisation conditions. In one of these forms, the central alternating tetramer has a Z-DNA conformation, while the initial cytosine swings out and forms a Watson-Crick base-pair with the terminal guanine of a symmetry-related molecule. In this communication a detailed comparison between solid and solution spatial conformation by NMR of …

Topochemical reactions of monomers with conjugated triple bonds. III. Solid-state reactivity of derivatives of diphenyldiacetylene

1971

ChemInform Abstract: COMPLEXES OF ORGANOMETALLIC COMPOUNDS PART 42, SPECTROSCOPIC STUDIES OF N,N′-ETHYLENEBIS(ACETYLACETONEIMINE) AND N,N′-ETHYLENEBI…

1975

Abstract The nature of the 1 1 adducts formed from the ligands N,N′-ethylenebis(acetylacetonemine) and N,N′-ethylenebis(salicylideneimine) with Ph2PbCl2 and PhTlCl2 was investigated in the solid state and in methanol solution by IR, electronic and PMR spectroscopy, and by osmometry and conductivity. The adducts exist only in the solid state and dissociate fully into the parent compounds in solution. Polymeric structures are proposed for the solids, in which bis-monodentate ligands bridge the organometallic moieties.

The structure of ammonium pyrazolates in the solid state

2006

The crystals obtained by mixing equimolar amounts of diethyl 1H-pyrazole-3,5-dicarboxylate and the primary amines phenethylamine and homoveratrylamine are ammonium pyrazolate salts as determined by 13C and 15N CPMAS NMR. Copyright © 2006 John Wiley & Sons, Ltd.

Transferability of ASTM/NIST alanine–polyethylene recipe at ISS

2000

Abstract Alanine–polyethylene solid state dosimeters were prepared at Istituto Superiore di Sanita (ISS) following the recipe proposed by National Institute of Standards and Technology (NIST) with the goal of testing its transferability. Dosimeters were prepared using 95% alanine and 5% polyethylene, by weight. They are rugged and of increased sensitivity, repeatability and reproducibility as respect to the ISS alanine-paraffin pellets. Reproducibility of about 1% was obtained at 10 Gy and at 3 Gy if one single pellet or a stack of five dosimeters were used, respectively.

Polyoxometalate-Based Molecular Materials.

1998

Molecule-based materials with active physical properties, in particular electrical, magnetic, and optical, are a focus of contemporary materials chemistry research. Certainly, one reason for this interest has been the realization that these materials can exhibit cooperative properties typically associated with the inorganic network solids, as for example metallic conduction or even superconductivity,1 ferromagnetism,2 and nonlinear optical properties.3 With respect to the electrical properties, many important achievements were obtained in the 1970s with the discovery of the first molecule-based metal in 1972,4 namely the π-electron donor-acceptor complex [TTF][TCNQ] (TTF ) tetrathiafulvalen…