Double and triple

Dupre C, Lahmam-Bennani A and Duguet A 1991 About some experimental aspeots of double and triple ooinoidenoe teohniques to study eleotron impaot double ionizing prooesses Meas. Sol. Technol. 2 327... 

Double and triple covalent bonds can be formed between elements by the sharing of two or three electron pairs respectively. Consider the formation of ethene (ethylene), C2H4 ... 

Double and triple bonds are counted as if they were split into two or three single bonds, respectively. 

Double zeta valence or triple zeta valence calculations can be carried out by putting DZV or TZV in place of STO NGAUSS = 3 in the second line of the INPUT file in the GAMESS implementation. The calculated energies become progressively lower (better) for double and triple zeta basis sets... 

Roos augmented double- and triple-zeta ANO Available for Fl(8.v4/i) to i sAp id) through Zn(2Lvl5/il0r/6/) to (2Lvl5/il0r/6/4 ). 

Molecular models such as the one shown often do not explicitly show double and triple bonds Write a Lewis structure for this hydrocarbon showing the location of any multiple bonds Specify the hybndization state of each carbon (You can view this model in more detail on Learn mg By Modeling)... 

Univalent radicals have the endings -enyl, -ynyl, -dienyl, -diynyl, etc. When necessary, the positions of the double and triple bonds are indicated by locants, with the carbon atom with the free valence numbered as 1. Examples ... 

Should there be a choice for the fundamental straight chain of a radical, that chain is selected which contains (1) the maximum number of double and triple bonds, (2) the largest number of carbon atoms, and (3) the largest number of double bonds. These are in descending priority. 

Bivalent radicals derived from unbranched alkenes, alkadienes, and alkynes by removing a hydrogen atom from each of the terminal carbon atoms are named by replacing the endings -ene, -diene, and -yne by -enylene, -dienylene, and -ynylene, respectively. Positions of double and triple bonds are indicated by numbers when necessary. The name vinylene instead of ethenylene is retained for —CH=CH—. 

For purely alicyclic compounds, the selection process proceeds successively until a decision is reached (a) the maximum number of substituents corresponding to the characteristic group cited earliest in Table 1.7, (b) the maximum number of double and triple bonds considered together, (c) the maximum length of the chain, and (d) the maximum number of double bonds. Additional criteria, if needed for complicated compounds, are given in the lUPAC nomenclature rules. 

In presence of carbon-carbon double and triple bonds —C=C—C=C— In presence of two carbon-carbon triple bonds —C=C—C=C— Double bond... 

Rocket Propellants. SoHd rocket propellants are mostly based on chemically cross-linked polymeric elastomers to provide the mechanical properties required in launchings and the environmental conditions experienced in storage, shipment, and handling (see Elastomers, synthetic). Double-and triple-based nitrocellulose propellants are also employed as rocket propellants. 

Continuous Solvent—Extrusion Process. A schematic for a typical continuous process, widely used for making solvent propellant for cannons, is shown in Figure 7. This continuous process produces ca 1100 metric tons of single-base propellant per month at the U.S. Army Ammunition Plant (Radford, Virginia). Continuous processes have also been developed for double- and triple-base propellants and for stick as well as granular geometries. A principal aspect of these processes has been the extensive use of single- and double-screw extmders instead of the presses used in the batch process. 

Dibromoborane—dimethyl sulfide is a more convenient reagent. It reacts directly with alkenes and alkynes to give the corresponding alkyl- and alkenyldibromoboranes (120—123). Dibromoborane differentiates between alkenes and alkynes hydroborating internal alkynes preferentially to terminal double and triple bonds (123). Unlike other substituted boranes it is more reactive toward 1,1-disubstituted than monosubstituted alkenes (124). 

Many other examples ia the Hterature illustrate the possibiUties of chemoselective hydroborations (124,186—189). For example, selectivity between double and triple bonds has been shown (124). 

Unsymmetrical functional tetraorganotins are generally prepared by tin hydride addition (hydrostaimation) to functional unsaturated organic compounds (88) (see Hydroboration). The realization that organotin hydrides readily add to atiphatic carbon—carbon double and triple bonds forming tin—carbon bonds led to a synthetic method which does not rely on reactive organometatiic reagents for tin—carbon bond formation and, thus, allows the synthesis of... 

Adhesives and Sealants. Various grades of chloriaated paraffins are used as nonvolatile iaert fire-retardant plasticizers and modifying resias ia adhesives and sealants (3). They find wide appHcation ia polysulfide, polyurethane, acryUc, and butyl sealants for use ia building and constmction. The low volatihty high chlorine types are also employed ia sealants for double- and triple-glazed wiadows. 

The addition of nucleophiles to double and triple bond systems is often a convenient way of effecting an intramolecular ring closure. Addition to cyano groups has received considerable attention, as in addition to ring formation it provides a convenient method for the introduction of an amino group. Reaction of methyl Af-cyanodithiocarbimidate with Af-methylaminoacetonitrile resulted in displacement of methanethiol and formation of (314). Sodium ethoxide treatment in DMF converted (314) into a 4-amino-5-cyanoimidazole... 

In cold climates, many homes and businesses use double and triple pane tows. The air pocket between double and triple pane windows serves to insulate so that heat is not lost through the windows. Likewise, air bubbles in oil prevent the heat from escaping. 

The hybridization concept can also be applied to molecules containing double and triple bonds. The descriptive valence bond approach to the bonding in ethylene and... 

The earbon-to-hydrogen bond is always a single bond. While the resulting bond between earbon and hydrogen is always a single bond, earbon does have the capability to form double and triple bonds between itself and other carbon atoms, and/or any other atom that has the ability to form more than one bond. When a hydrocarbon contains only single bonds between earbon atoms, it is known as a saturated hydrocarbon when there is at least one double or triple bond between two carbon atoms anywhere in the molecule, it is an unsaturated hydrocarbon. When determining the saturation or unsaturation of a hydrocarbon, only the carbon-to-... 

Double and triple bonded hydrocarbons Fire and explosion... 

This ordering by singles, doubles and triples takes added meaning when the failure rates of the active and passive components (Table 1.4.3-1) are included. A doublet has a failure frequency that is the product of the two failure rates a triplet is the product of three... 

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