Reactions crystal structure

The objectives in this chapter are to illustrate the various kinds of information that are immediately derivable from a crystal-structure analysis by X-ray diffraction and their applications to alkaloid molecules. From unequivocally providing the structural formula, stereochemistry, and absolute configuration of an alkaloid of unknown formula to establishing the spatial arrangement of the atoms, particularly the disposition of the atoms that are the reactive centers or that provide a steric hindrance to reaction, crystal-structure analyses are extremely useful and often indispensable. 

Keywords Iminosilanes / Silaamidides / Addition Reactions / Crystal structure... 

If the first formed phosphonium salt in scheme (6.436) is allowed to react with diphenylphosphi-nous chloride according to scheme (6.904), the ultimate product is a stable water-soluble four-membered ring compound, mp=385°C, which does not undergo ylid reactions. Crystal structure analysis shows that all the P-C distances are rather short, thus indicating extensive delocalisation over the ring and the exocyclic bonds. Contributing structures may be as in [79]... 

A review entitled thiophenes from Viktor Meyer to Poly (thiophene) some reactions and synthesis was published in a special issue of Phosphorus, Sulfur and the related elements (13PS287). Over 80 reaction schemes are presented outlining important discoveries in the chemistry of thiophenes. Another review generalized published data on the reactions of 4-(2-R-aryl)-1,2,3-thia- and selenadiazoles (13RJOC479). Special emphasis on the use of these selenadiazole for the synthesis of 1-benzothiophenes, 1-benzosele-ophenes, and their more complex derivatives was presented. A recent review on recent advances in the use of the Wfllgerodt-Kindler reaction in thiophene syntheses appeared this year (13CSV7870). Extensive reviews on selenium and tellurium chemistry from small molecules to biomolecules and materials (B-13M001) as well as data on the synthesis, reactions, crystal structures, and spectral characteristics of benzo[b]tellurophene, dibenzo[b,d]... 

Solid-State Reaction Crystal Structure and Solid-State... 

Diederich F, Jonas U, Gramlich V, Herrmann A, Ringsdorf H and Thilgen C 1993 Synthesis of a fullerene derivative of benzo[18]crown-6 by Diels-Alder reaction complexation ability, amphiphilic properties, and x-ray crystal structure of a dimethoxy-1,9-(methano[1, 2]benzomethano)fullerene[60] benzene clathrate Helv. Chim. Acta 76 2445-53... 

Oxazolidine-4,5-dione, At-benzoyl-synthesis, 6, 231 Oxazolidinediones reactions, 6, 214 structure, 6, 179 Oxazolidine-2,4-diones as anticonvulsants, 1, 166 NMI 6, 181 reactions, 6, 214 s mthesis, 6, 231 OxazoIidine-2,5-diones crystal structure, 6, 185 reactions, 6, 214 polymers, 1, 307 s mthesis, 6, 231 Oxazolidine-4,5-diones synthesis, 6, 231 Oxazolidines... 

Oxetane, 3,3-bis(trimethylaminomethyl)-methane sulfonate X-ray crystal structure, 7, 365 Oxetane, 3-bromo-synthesis, 7, 390 Oxetane, 2-t-butyl-3-methyl-synthesis, 7, 399 Oxetane, 2-chloro-reactions, 7, 390 Oxetane, 3-chloro-synthesis, 7, 390... 

Oxetane-2-methanol, t/ireo-a,3,3,4,4-pentamethyl-3,5-dinitrobenzoate X-ray crystal structure, 7, 365 Oxetane-3-methanol, 3-alkyl-reactions... 

Reaction center hydropathy plots agree with crystal structural data... 

Crystal Structure, Crystal Defects and Chemical Reactions... 

Crystal structure, crystal defects and chemical reactions. Most chemical reactions of interest to materials scientists involve at least one reactant in the solid state examples inelude surfaee oxidation, internal oxidation, the photographie process, electrochemieal reaetions in the solid state. All of these are critieally dependent on crystal defects, point defects in particular, and the thermodynamics of these point defeets, especially in ionic compounds, are far more complex than they are in single-component metals. I have spaee only for a superficial overview. 

Reductive coupling reaction of fluonnated vinyl iodides or bromides has been used as a route to fluorinated dienes [246, 247, 248, 249, 250. Generally, the vinyl iodide is heated with copper metal in DMSO or DMF no 1 ntermediate perfluorovmy I-copper reagent is detected. Typical examples are shown m equations 163-165 [246, 247, 249. The X-ray crystal structure of perfluorotetracyclobutacyclooctatetraene, prepared via coupling of tetrafluoro-l,2-diiodocyclobutene with copper, is planar... 

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