Acetylene physical constants

Polyacetylenes (or Polyynesj. See under Acetylenic Condensation and Polymerization Products in Vol 1, A62-L to A63-L. Selected polyacetylene expl compds as an adjunct to this article are presented below, as well as addnl refs Addnl Refs 1) A.L. Henne K.W. Greenlee, Preparation and Physical Constants of Acetyl-... 

Preparative Data and Physical Constants of Cycuc Acetals from the Reaction OF Acetylene with Alcohols (Stoichiometric Quantities)... 

Property data from the literature (1-55,84-93) are given in Table 3-1. Critical constants have been determined experimentally for acetylene and methylacetylene (1-7). Critical pressure and volume are estimated for 1 butyne and 2 butyne (5). Additional property data such as acentric factor, enthalpy of formation, lower explosion limit in air and solubility in water are also available. The DIPPR (Design Institute for Physical Property Research) project (5) and recent data compilations by Yaws and co-workers (44-55) were consulted extensively in preparing the tabulation. 

Whilst the synthesis of new transition metal-olefin and -acetylene complexes continues unabated, only a relatively small amount of data has accumulated on the thermodynamic stability of these complexes and these are restricted almost exclusively to complexes of the unsatured species acting as monodentate ligands. Metals able to coordinate strongly with unsaturated ligands are restricted to those in a small triangle around the centre of the periodic table, and designated class (b) acceptors by Ahrland et al., 0>. Class (b) acceptors include Cu(I), Rh(II), Ag(I), Pt(II) and Hg(II). However the majority of such metals form inert complexes which are either very readily oxidised or involve solubility problems. If thermodynamic stability constants are to be measured reliably, the equilibrium should be reached reasonably quickly, the reaction should be clean and the stoichiometry should be known or easily deduced. Furthermore, the equilibrium must be followed by means of suitable electrodes or changes in some physical property of the reaction mixture. The solvent is therefore important. 

In their study of association in ammonia + acetylene mixtures, Cheh, O Connell, and Prausnitz calculated the physical contribution to B12 from potentials that included hard-core as well as multipole interactions. The existence of vapour-phase complexes of ethylene with ammonia and methanol and of methanol with pentane has been inferred from virial coefficient data. King and co-workers have obtained association constants for COj with naphthalene, methanol, ethanol, and diethyl ether, and for HgO with CO2 and... 

Cartesian system. It is hoped diat the reflect electric properties of individual atoms in molecules. King et al. [105] in their original study have found out that for hydrogen atoms are almost constant for many types of hydrocarbons with the exception of acetylene. An accurate physical interpretation of effective atomic charges as derived from Eq. (4.31) is, however, difficult to produce. The problem will be discussed in the following part. 

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