tetrahydrobenzo[b]pyran derivatives 1 were utilized for the synthesis of several new pyrano[2,3-d]pyrimidine derivatives 2. compound 2 was obtained in the presence of ac2o/h2so4 (as a catalyst) and was confirmed by spectroscopic data such as ir, 1h nmr and 13c nmr. ab initio calculation was carried out to study geometric optimization, thermodynamic parameters, aromaticity and dynamic process of...

the dimerization constants of safranine t have been determined by studying the dependence of its absorption spectra on the temperature in the range 30–70 ◦c at different total concentrations of safranine t (1.03×10−5, 1.44×10−5 and 1.73×10−5 m). the monomer–dimer equilibrium of safranine t has been determined by applying mcr-als method on the absorption spectra. the quantitative analysis of the...

pyspeckit is a toolkit and library for spectroscopic analysis in Python. We describe the package highlight some of its capabilities, such as interactively fitting model to data, akin historically widely-used splot function IRAF. employs Levenberg-Marquardt optimization method via mpfit lmfit implementations, important assumptions regarding error estimation are described here. Wrappers use pymc ...