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141-30-0, Name is 3,6-Dichloropyridazine, belongs to pyridazine compound, is a common compound. category: pyridazineIn an article, once mentioned the new application about 141-30-0.
Recent advances in computing heteroatom-rich five- and six-membered ring systems
Recent developments in computer technology and the increasing efficiency and accuracy of current ab initio and density functional programs allow the investigation of increasingly complex systems. Molecules that could be treated only at the semiempirical level ten years ago can now be computed at the density functional or the MP2 level with basis sets of double-zeta quality. Very often, these calculations are accurate enough to explain experimental findings, and consequently many experimental studies are augmented by quantum chemical calculations. However, in many cases just a few kilocalories per mole may decide between different reaction mechanisms, different explanations of physical effects, or even a preferred tautomer or conformer. Since the inherent errors of MP2 and DFT calculations are still significantly larger than chemical accuracy, high-level calculations are mandatory for many problems. This holds particularly true for the investigation of reaction barriers involving bond-breaking processes. Although these problems have been recognized by many investigators, a substantial number of papers lack sufficient accuracy. This accuracy problem appears to be more severe for heteroatom-rich species than for other systems, in particular for systems with adjacent heteroatoms. However, DFT calculations were found to cope surprisingly well with the geometric parameters of most of these systems. As is common in heterocyclic chemistry, many studies concern tautomeric equilibria. While quantum chemical calculations are straightforward for the question of the most stable isomer, experiments are sometimes very demanding. Therefore, quantum chemistry can easily provide answers that may require substantial experimental effort. Comparatively few studies concern the investigation of entire reaction paths. This is much more demanding than computing a limited number of tautomers, of course, but usually provides a very detailed picture of the reaction mechanism. In certain cases, it was only possible to judge the nature of a chemical reaction on the basis of quantum chemical calculations. Most studies concerning pyrimidines originate from biochemical questions. Since these systems are dominated by hydrogen-bonding and/or dispersion contributions, methods beyond the Hartree-Fock level are mandatory. The success of quantum chemical studies in this field is impressive and many effects could be explained on the basis of these theoretical investigations.
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Reference：
Pyridazine – Wikipedia,
Pyridazine | C4H4N1873 – PubChem