Molecules containing three carbon atoms

A number of groups have studied one or more of the C3H4 isomers [213, 677—680, 806]. It has been proposed that the loss of H- from the allene ion proceeds via two pathways to give two different (C3H3)+ structures [213] (cf. loss of Cl- from the propargyl chloride ion). A kinetic shift has been determined for formation of (C3H3)+ from allene [806]. Some evidence was found that the cyclopropene and propyne ions isomerised to the allene structure before they decomposed [678]. 

Breakdown diagrams have been determined for acetone both by threshold and fixed wavelength PIPECO [154, 330, 619, 692, 797]. Perdeuteroacetone has also been studied [619]. 

The loss of Cl from the metastable propargyl chloride ion has been studied by PIPECO as a function of time and, again, two first-order rate coefficients were necessary to describe the kinetics [23, 840], At a photon energy of 11.02 eV E = 0.58 eV), these rate coefficients were 

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Two different alkanes are known with the molecular formula C Hm- In one of these, called butane, the four carbon atoms are linked in a straight (unbranched) chain. In the other, called 2-methylpropane, there is a branched chain. The longest chain in the molecule contains three carbon atoms there is a CH3 branch from the central carbon atom. The geometries of these molecules are shown in Figure 22.2 (p. 581). The structures are... 

Consider the combustion of propane (CsHg). Commonly used as fuel in gas grills, propane (a gas) combines with oxygen (O2, a gas) to form carbon dioxide (CO2, a gas) and water (H2O, a liquid). Because each propane molecule contains three carbon atoms and because carbon dioxide (with one carbon atom) is the only product that contains carbon, each propane molecule that reacts must produce three CO2 molecules. Similarly, the eight hydrogen atoms from each propane molecule should produce four water molecules. These data give ten oxygen atoms in the products (from three CO2 and four H2O molecules), so there must be five O2 molecules in the reactants. Thus, the chemical equation for this reaction is... 

This equation tells us that the conversion of one molecule of D-glucose, which contains six carbon atoms, to two molecules of lactate, which contain three carbon atoms each, is accompanied by the generation of two molecules of ATP from its constituents ADP and Pi. Note that the structure of ADP is identical to that of ATP with the exception that the terminal phosphate group is missing. 

In a reaction that similarly relies on the acidity of benzylic protons in arene-ruthenium(II) complexes, the r 6-mesitylene complex 92 containing bidentate (C6F5)2PCH2CH2P(C6F5)2 loses two molecules of HF on treatment with proton sponge to give the di-strapped salt 93 in which each tether contains three carbon atoms [Eq. (18)]).83... 

The recent discovery of spherical molecules containing 60 carbon atoms arranged over the surface of a sphere, each atom being linked to three... 

The structure of lecithin is illustrated here. Glycerol, which contains three carbon atoms, serves as the backbone of the lecithin molecule. The two fatty acids are linked to glycerol at carbon atoms 1 and 2 and the phosphate group is linked to carbon atom 3. Choline is, in turn, linked to the phosphate group. Typically, though not always, the fatty acid attached to carbon 1 of glycerol is saturated, while that attached to carbon 2 is unsaturated. 

These concepts are difficult for many people to fully grasp unless they use molecular models. This form of stereoisomerism is known as optical isomerism because chiral molecules have unique effects on polarized light. Molecules containing all carbon atoms with three or fewer different entities attached cannot be enantiomers and are called achiral. 

The molecule contains a carbon atom, two chlorine atoms, and two fluorine atoms. There are two covalent C-Cl bonds and two covalent C-F bonds. The Cl and F atoms have three lone pairs each. 

Step 3 We start with GgHg because it is the most complicated molecule. GgHg contains three carbon atoms per molecule, so a coefficient of 3 is needed for GO2. 

The building blocks of all carbohydrates are the simple sugars called monosaccharides. A monosaccharide can be a polyhydroxy aldehyde (aldose) or a polyhydroxy ketone (ketose). The simplest monosaccharides contain three carbon atoms and are called trioses (tri meaning three ). Glyceraldehyde is the aldose with three carbons (an aldotriose), and dihydroxy acetone is the ketose with three carbon atoms (a ketotiiose). Figure 16.1 shows these molecules. 

One molecule of glyceraldehyde-3-phosphate has already been produced by the aldolase reaction we now have a second molecule of glyceraldehyde-3-phosphate, produced by the triosephosphate isomerase reaction. The original molecule of glucose, which contains six carbon atoms, has now been converted to two molecules of glyceraldehyde-3-phosphate, each of which contains three carbon atoms. 

As a comparison, note that 32 moles of ATP can be obtained from the complete oxidation of one mole of glucose but glucose contains 6, rather than 18, carbon atoms. Three glucose molecules contain 18 carbon atoms, and a more interesting comparison is the ATP yield from the oxidation of three glucose molecules, which is 3 X 32 = 96 ATP for the same number of carbon atoms. The yield of ATP from the oxidation of the lipid is still higher than that from the carbohydrate, even for the same number of carbon atoms. The reason is that a fatty acid is all hydrocarbon except for the carboxyl group that is, it exists in a... 

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