Compounds Containing Triple Bonds

One compound that contains a triple bond is ethyne (acetylene), C2H2. Its Lewis formula is 

An important use of ethylene, C2H4, is in the manufacture of polyethylene, a nonbreakable, nonreactive plastic. 

The VSEPR theory predicts that the two electron groups around each carbon atom are 180° apart. 

The two carbon atoms form one sigma bond by head-on overlap of the sp hybrid orbitals each C atom also forms a sigma bond with one H atom. The sp hybrids on each atom are 180° apart. Thus, the entire molecule must be linear. 

A triple bond consists of one sigma bond and two pi bonds. 

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RC = CNa and derived compounds. Sodium acetylides have been used for the synthesis of a large number of organic compounds containing triple bonds. 

Furthermore, compounds containing triple bonds can be obtained from sp hybrid orbitals, sp hybridisation produces two orbitals oriented at 180° to each other, as shown by the filled lobes in Fig. 1.4(a), which can form co-linear cr-bonds. This leaves two p-electrons, shown by the shaded lobes in Fig. 1.4(a), which are free to form rc-bonds aligned with the cr-bond, as in acetylene, C2H2, shown in Fig. 1.4(b). 

Compounds containing triple bonds are also Diels-Alder dienophiles. With this in mind, draw the products of each reaction. 

This section concerns compounds containing triple-bond unsaturation, thus cyanates and thiocyanates (R—O—C=N R—S—C=N), but not the iso-compounds (R—N=C—O R—N=C=S) are discussed. Early work has been reviewed. 

The 1,3-dipolar character of the azido group has been previously exploited for [2 + 3]-cycloaddition reactions of glycosyl azides with compounds containing triple bonds. It is known that formation of 1,4-disubstituted 1,2,3-triazoles is favored over the 1,5-disubstituted ones. Motivated mainly by pharmacological considerations (in order to obtain compounds with cytostatic properties), syntheses of a great number of 1-A -glycosyl-1,2,3-triazole derivatives have been reported. " " "" ... 

Compounds Containing Triple Bonds 8-16 A Summary of Electronic and Molecular Geometries... 

Carbon forms a number of compounds containing triple bonds. For example, the compound ethyne, C2H2, contains a carbon-carbon triple bond. 

Alkenes and alkynes are similar in structure to the alkanes except the alkenes contain a carbon-to-carbon double bond (C=C) and the alkynes contain a carbon-to-carbon triple bond (C=C). The name prefixes are exactly the same as for the alkanes with the same number of carbons, but the endings are -one for compounds with double bonds and their derivatives and -yne for compounds with triple bonds... 

Acetylenes (alkynes contain triple bonds) C C c2h2, c3h4, c4h6,. .., C H2 2 Ethyne, propyne, butyne (acetylene, methyl acetylene, ethyl acetylene) Unsaturated compounds... 

By writing about complexes containing triple bonds between phosphorus and transition metals, one has to take into account the triple-bond character of phosphinidene complexes which are in a nearly linear coordination mode (type C) in contrast to the usual bent coordination mode D possessing typical double-bond features. Due to the additional r-donation bonding ability of the PR moiety to the metal atom in type C and the observed bond lengths, this type of complexes has to be included into the classes of metal-phosphorus triple bond compounds. Thus, at the end of this review will appear a chapter highlighting the appropriate compounds of type C. 

Alkynes are hydrocarbons that contain a carbon-carbon triple bond. A triple bond consists of a cr bond and two tt bonds. The general formula for the alkynes is C li2n-2- The triple bond possesses two elements of unsaturation. Alkynes are commonly named as substituted acetylenes. Compounds with triple bonds at the end of a molecule are called terminal alkynes. Terminal —CH groups are called acetylenic hydrogens. If the triple bond has two alkyl groups on both sides, it is called an internal alkyne. 

Basidiomycetes. These compounds tend to be highly unstable and some are even explosive if sufficient amounts are accumulated. Since only very small amounts are present in plants, this does not present any widespread hazard. Whilst fatty acids containing several double bonds usually have these in a non-conjugated array, molecules containing triple bonds tend to possess conjugated unsaturation. This gives the compounds intense and highly characteristic UV spectra which aids their detection and isolation. 

Ethynylestradiol is a synthetic compound whose structure closely resembles the carbon skeleton of female estrogen hormones. Because it is more potent than its naturally occurring anaiogues, it is a component of several widely used oral contraceptives. Ethynylestradiol and related compounds with similar biological activity contain a carbon-carbon triple bond. In Chapter 11 we learn about alkynes, hydrocarbons that contain triple bonds. 

In addition to the reduction of N2 and H+, Mo nitrogenase has been shown to reduce a wide range of small molecules that contain triple bonds (e.g., C2H2, CN, and N3). Many of these compounds have yet to be tested as substrates with Mo-independent nitrogenases, but the reduction pattern of one such analog (C2H2) has proved interesting. 

We have systematically studied the possibility of preparing various types of cellulose derivatives containing triple bond. Certain chemical transformations of the resulting compounds have also been accomplished. 

Four of the seven known metal tetrakis-borohydrides—Zr, Hf, Th, and U borohydrides (1,2)—were first synthesized about 30 years ago during the Manhattan project. They were found to be very volatile and reactive compounds. In recent years, much structural, spectroscopic, and chemical studies were done on these molecules. New tetrakis-borohydrides of the actinides Pa, Np, and Pu have recently been prepared by analogous reactions used in the syntheses of U and Th borohydrides (3). The Pa compound, Pa(BHi+K, is iso-morphous to and behaves like U(BHi+)i+ and Th(BHi+)i+ while x-ray studies on Np(BHi+)i+ and the isostructural Pu(BHi+)i+ have shown that they resemble the highly volatile Zr and Hf compounds both in structure and properties. All seven compounds contain triple hydrogen bridge bonds connecting the boron atom to the metal. 

Compounds containing double or triple bonds between carbon atoms are said to be unsaturated. The alkenes contain double bonds, alkynes contain triple bonds, and aromatics contain a six-membered ring with three double bonds, objectiva 1, Exercise 2.2. In the lUPAC nomenclature system, alkene names end in -ene, and alkynes end in -yne. 

Compounds containing triple M = M bonds have or electronic... 

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