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Atoms, Table

Isoparaffins have boiling points lower than normal paraffins witTilHe same number of carbon atoms. Table 1.1 presents some physical properties of selected paraffins... [Pg.4]

Another scheme for estimating thermocheraical data, introduced by Allen [12], accumulated the deviations from simple bond additivity in the carbon skeleton. To achieve this, he introduced, over and beyond a contribution from a C-C and a C-H bond, a contribution G(CCC) every time a consecutive arrangement of three carbon atoms was met, and a contribution D(CCC) whenever three carbon atoms were bonded to a central carbon atom. Table 7-3 shows the substructures, the symbols, and the contributions to the heats of formation and to the heats of atomization. [Pg.324]

Electronic Energies of Atoms and Single-Positive Ions in the First Row of the Atomic Table... [Pg.241]

Plot the calculated first IPs as a function of the atomic number Z for the elements from H to Ne in the atomic table. The plot has a characteristic shape that should be familiar from earlier courses. These plots are frequently given in the experimental units of electron volts (eV hartrees x 27.21 = eV) or kilojoules per mole (kJ mol hartrees x 2625 = kJmol ). Write a paragraph or two in your project report explaining why the graph of IP vs. Z appears as it does. [Pg.242]

Physical Properties. The physical properties of organosilanes are determined largely by the properties of the sihcon atom (Table 2). Because sihcon is larger and less electronegative than either carbon or hydrogen, the polarity of the Si—H bond is opposite to that of the C—H bond (Table 3). This... [Pg.24]

Comparison of the relevant data shows that an adjacent oxygen (Table 5) and especially a sulfur atom (Table 6) induce lower field shifts than either type of nitrogen atom. [Pg.14]

Two now classical papers 61MI40400, 62JCS2927) contain almost all the experimental thermochemical data on pyrazole and indazole. Heats of combustion determined by Zimmerman (61MI40400) have been used by Dewar to calculate the heats of atomization (Table 25) (69JA796). Quantum mechanical calculations, carried out by Dewar (69JA796) or Olivella 81JHC1189), gave accurate empirical values. [Pg.208]

Table 2.3 shows very obvious parallels with the TMS scale of C shifts. Thus, the shifts (Table 2.3) decrease in size in the sequence nitroso, nitro, imino, amino, following the corresponding behaviour of the shifts of carbonyl, carboxy, alkenyl and alkyl carbon atoms (Table 2.2). [Pg.15]

One-bond CH coupling constants Jqh ( Jch) proportional to the s character of the hybrid bonding orbitals of the coupling carbon atom, (Table 2.6, from left to right)according to... [Pg.26]

It is also useful for structure elucidation that Jqh increases with the electronegativity of the heteroatom or substituent bound to the coupled carbon atom (Table 2.6, from top to bottom). [Pg.26]

The subunits which can be defined can include atoms or collections of atoms corresponding to functional groups. The subunits can be represented as regions of space defined by electon density. These representations correspond well with the qualitative concepts that arise from valence bond stmctures. The mathematical evaluation can assign shape and charge density to atoms. Table 1.17 gives the C and H charge densities in some... [Pg.58]

As its name implies, this complex transfers a pair of electrons from NADH to coenzyme Q a small, hydrophobic, yellow compound. Another common name for this enzyme complex is NADH dehydrogenase. The complex (with an estimated mass of 850 kD) involves more than 30 polypeptide chains, one molecule of flavin mononucleotide (FMN), and as many as seven Fe-S clusters, together containing a total of 20 to 26 iron atoms (Table 21.2). By virtue of its dependence on FMN, NADH-UQ reductase is a jlavoprotein. [Pg.681]

Atom-kem, m. atomic nucleus, -kette,/. chain of atoms, atomic chain, -lage, /. atomic layer atomic position, -lehre, /, doctrine of atoms, atomic theory, -mechanik, /. mechanics of the atom, -modell, n, atomic model, -nummer, /, atomic number, -ord-nung, /. atomic arrangement, -refraktion, /. atomic refraction, -rest, m. atomic residue (= Atomrumpf). -ring, m. ring of atoms, -rumpf, m. atomic residue or core (remainder of an atom, as after removal of some electrons), -schale, /, atomic shell, -strabl, m. atomic ray, -tafel, /, atomic table, atomtbeoretisch, a. of or according to the atomic theory,... [Pg.37]

One of the most striking features of the common fatty adds is that they have an even number of carbon atoms (Table 27.1, p. 1062). This even number results because all fatty acids are derived biosynthelically from acetyl CoA by sequential addition of two-carbon units to a growing chain. The acetyl CoA, in turn, arises primarily from the metabolic breakdown of carbohydrates in the glycolysis pathway that weTl see in Section 29.5. Thus, dietary carbohydrates consumed in excess of immediate energy needs are turned into fats for storage. [Pg.1138]

Complex IV consists of 13 peptides, two heme A groups (cytochrome a and a3> and two or three Cu atoms (Table 2). It spans the inner membrane and protrudes into the intermembrane space. Complex IV catalyzes the reduction of dioxygen by oxidized cytochrome c, and four protons derived from the matrix are consumed in the reaction. [Pg.128]

Charney et al. (2001), Harvey (1985), Matthew (1971), and Wesson and Smith (1977) have discussed the pharmacology of barbiturates. Barbiturates are derived from barbituric acid, which is the product of the fusion of malonic acid and urea. Barbituric acid lacks CNS activity. The two main classes of barbiturates are the highly lipid-soluble thiobarbiturates, in which sulfur replaces oxygen at the second carbon atom of the barbituric acid ring, and the less soluble oxybarbiturates, with oxygen at the second carbon atom (Table 3-3). Highly lipid-soluble barbiturates have a more rapid onset, a short duration of action, and greater potency than those with lower lipid solubility. [Pg.138]

Benzene has often been used as a test system for vibrational calculations using a variety of different electronic structure algorithms. The molecule exhibits regular hexagonal planar symmetry with six carbon atoms joined by a bonds and six remaining p-orbitals which overlap to form a delocalised n electron over all six carbon atoms. Table 1 shows comparisons of several different methods for benzene. [Pg.34]

Chlorine molecules must be broken apart into chlorine atoms. Table gives the bond energy BE) of molecular chlorine, 240 kJ/mol. We need — mole of CI2 to form 1 mole of NaCl, so the energy... [Pg.546]

Upon reduction with methanol at 625 K, the vanadium ions in these samples exhibited an apparent, average degree of reduction of 0.5-0.8 electrons per atom (Table 3). This value... [Pg.340]

The alkene series of hydrocarbons is characterized by having one double bond in the carbon chain. The characteristic formula for members of the series is C H2 . Since there must be at least two carbon atoms present to have a carbon-to-carbon double bond, the first member of this series is ethene, C2H4, also known as ethylene. Propene (propylene), C,Hh, and butene (butylene), C4HK, are the next two members of the series. Note that the systematic names of these compounds denote the number of carbon atoms in the chain with the name derived from that of the alkane having the same number of carbon atoms (Table 21-2). Note also that the characteristic ending -ene is part of the name of each of these compounds. [Pg.320]

Calculation of the heats of formation (H) of the bonds between oxygen atoms and PANI (62) AC atoms (Table 2) shows the bonds in which one of the AS s (Cl, C7, Cl 3, Cl 8) forms a bond to the nitrogen atom to be characterized by the highest H values. In this case, the stability of adsorption complexes is 10 - 15 kcal higher than that of the complexes formed on the carbon atoms not bonded to nitrogen. Thus, oxygen adsorption on pairs of AS s which contain one of the carbon atoms Cl, C7, C13, C18 is more probable than that on pairs of side chain sites. [Pg.117]

Central E14-C bonds are longer (about 0.1 A) than the E14-CMe bonds, and the E14-C-E15 angles are greater than the ideal tetrahedral angle of 109.4°, which indicates considerable steric strain due to short nonvalent contacts X---E15. For betaines of the tin series, the E14 E15 distance approaches the sum of van der Waals radii of atoms (Table XI). This regularity is distinctly seen in the experimental X-ray data (see Section 3). [Pg.75]

Figure 1 shows schematically the structure of s-trans-1,3-butadicnc. Several studies show that proper geometry parameters are only obtained with a basis set of at least double-f quality, including polarization functions for carbon atoms. Table 1 presents a selection of the results obtained at several levels of calculation, using a basis set of this kind. [Pg.5]


See other pages where Atoms, Table is mentioned: [Pg.672]    [Pg.1327]    [Pg.416]    [Pg.12]    [Pg.27]    [Pg.1327]    [Pg.131]    [Pg.311]    [Pg.795]    [Pg.76]    [Pg.15]    [Pg.202]    [Pg.618]    [Pg.130]    [Pg.169]    [Pg.431]    [Pg.435]    [Pg.435]    [Pg.311]    [Pg.110]    [Pg.122]    [Pg.209]    [Pg.55]    [Pg.28]    [Pg.264]    [Pg.19]    [Pg.9]    [Pg.76]   
See also in sourсe #XX -- [ Pg.51 ]




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