Quantitative Correlation of Physical and Chemical Properties with Chemical Structure: Utility for Prediction

Solubilidade das substâncias orgânicas

“…Além disso, o conhecimento da solubilidade é necessário para a previsão do destino ambiental de contaminantes e poluentes, processos de adsorção no solo e fatores de bioconcentração de agrotóxicos. 7 A solubilidade de uma substância orgânica está diretamente relacionada com a estrutura molecular, especialmente com a polaridade das ligações e da espécie química como um todo (momento de dipolo). Geralmente, os compostos apolares ou fracamente polares são solúveis em solventes apolares ou de baixa polaridade, enquanto que compostos de alta polaridade são solúveis em solventes também polares, o que está de acordo com a regra empírica de grande utilidade: "polar dissolve polar, apolar dissolve apolar" ou "o semelhante dissolve o semelhante".…”

Toward the Toxicology of Some Nitro-Compounds

“…Hansch et al proposed Hansch-Fujita model and turned a new page of QSAR or QSPR [10,11] in the research of activities of compounds. By the beginning of twentieth century, it is commonly believed that bioactivities of compounds are mainly determined by their physical properties, including vapor pressure, Henry' s law constants, water solubility, octanol/water partition coefficients, heats of formation and ionization potentials of explosive TNT [12], acidity and basicity of hydrogenbond, solubilit, surface tension, dipole moment, refractive index and dielectric constant [13], solid, liquid and gaseous enthalpies of formation in terms molecular electrostatic potentials [14], density, vaporization enthalpy, heat capacity, surface tension, isothermal compressibility and dielectric constant [15~18], the role of polarization in the interaction between chemistry and biology [19].…”

A quantitative relationship between Tgs and chain segment structures of polystyrenes

“…T g is a fundamental characteristic and is taken as the most crucial property of amorphous polymeric materials [1] . The nature of the theory in the glass and glass transition is unsolved, however, is taken as the deepest and most interesting problem in solid stated theory.…”

“…Recently, some quantum chemical descriptors calculated from repeating units or monomers were used to develop QSPR models for T g s of polymers [10][11][12] . Due to the large and variable size of polymer molecules, the QSPR models stated above, together with QSPR models of other polymer properties, are modeled by extrapolation from monomer structures or repeating units [1] . These methods fail to account for the influences from neighboring repeating units.…”