Structure alkyls

Ternary materials that incorporate carbon into a boron-nitrogen framework are expected to exhibit extreme hardness as a result of their diamond-like structures. Alkyl-, vinyl- and alkynyl-substituted borazines are potential... 

A,B-Diheteropentalenes have only limited solubility in water. The hydrogen donor properties of the NH site of pyrrole and the hydrogen acceptor property of the oxygen atom of the furan ring can increase the solubility of the compounds containing these heteroatoms relative to the systems with only sulfur or selenium atoms in their structure. Alkylation at the nitrogen of furo[3,2-6]pyrrole derivatives increases the solubility in ethanol and other organic solvents. 

Alkane Number of Carbon atoms Structure Alkyl Structure... 

Hie configuration of onium ions stems from their electronic structure. Alkyl groups in oxonium ions are directed along the edges of a pyramid with angles at the top depending, however, in some systems on the steric requirements. 

Dacarbazine (DTIC) is chemically characterized by a dimethyl-triazeno structure. Alkylation, via a methyldiazonium ion metabolite is the most likely mechanism involved in its anti-tumour activity. Reconstituted solutions of DTIC are administered as slow IV bolus injection or the infusion of diluted solutions. DTIC is sensitive to photonic energy and heat. 

Formation of sub-bituminous coal seems to involve O loss through conversion of dihydroxy phenolic units (catechols) to monohydroxy units (phenols and alkylphenols), as shown in Fig. 4.7, based on the simple distribution of pyrolysis products, which are dominated by phenol, ortho-cresol (2-methylphenol) and 2,4-dimethylphenol (Hatcher 1990). Oxygenated aliphatic structures (alkyl hydroxyls and ethers) seem to be absent. Figure 4.8 shows the types of units present at various stages of biochemical coalification, based on a random hgnin polymer. 

The X-ray diffraction pattern of saponite exhibits a relatively weak and broad (001) reflection compared with montmorillonite, indicating a lack of long-range layer ordering. This characteristic of saponite can be ascribed to the three-dimensional voluminous house-of-cards structure. The house-of-cards structure also contributes to the high catalytic activity in comparison to montmorillo-nites, which do not form the house-of-cards structure. Alkylation activity... 

This reaction proceeds via a dinuclear intermediate, as shown in Scheme 5.24. The SnBu3 group of the ortho substituent of the phenyl ligand is able to approach the Cu-Ph bond of another cuprate unit in the eight-membered cyclic dimer structure. Alkyl and phenyl hgand exchange between Sn and Cu centers in both cuprates leads to the introduction of a phenyl group to the Sn center. 

To date, the best-studied SAM system has been that of self-assembled alkanethiolates on gold, where thiols adsorb onto the gold surface in an initial lying-down phase followed by rearrangement into a standing-up phase, which completes the monolayer and results in highly ordered, two-dimensional structures. Alkyl phosphates and phosphonates constitute two further systems that have been shown to form ordered SAMs on metal oxide surfaces. - Transition metal oxides such... 

A particular attribute of octasubstituted phthalocyanines is their liquid crystalline behavior. Phthalocyanines substituted in peripheral positions by long-chain substituents form, depending on the structure (alkyl or alkoxy), liquid discotic (from the disclike shape of the molecules) crystalline phases [68-71 ] or columnar meso-phases [72]. Liquid crystalline phases are found for side chains longer than C4 or Q (depending on the metals and substituents used) [73]. In these mesophases the phthalocyanine moieties stack in columns with arrangements of different symmetry (Fig. 15.8), depending on the nature of the side chains [71,74]. Only chains connected with a heteroatom X (X = O, S) to the aromatic macrocycle show an arrangement with the molecular planes perpendicular to the column axis. 

A particular attribute of octasubstituted phthalocyanines is their liquid crystalline behavior. Phthalocyanines substituted in peripheral positions by long chain substituents form, depending upon the structure (alkyl or alkoxy), liquid discotic (from the disc-like shape of... 

A series of alkyl-substituted anthracenes (14,18, and 24) were prepared from Diels-Alder reactions of bis(benzyne) equivalent 4 or dehydronaphthalene equivalent 8 with alkyl-substituted furans (11 or 27). The structural features of the crystals were characterized by X-ray crystallographic analysis. Depending on the length, position, and number of alkyl side chains, the molecular structures (alkyl conformations) and packing arrangements of the alkyl-substimted anthracenes changed drastically. Consequently, such modifications led to diffaent fluorescait properties for the anthracenes in the solid-state. 

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