Molecular energetics of 4-methyldibenzothiophene: An experimental study

Assessment of Gaussian-4 theory for the computation of enthalpies of formation of large organic molecules

“…Thus, although the deviations of the G4 enthalpies of formation from the experimental ones are larger than for molecules from test set [4], the accumulation of errors due to the size of the molecule is not observed for nitrogen heterocycles, at least with the increase of non-hydrogen atom number from 6 to 14. It is worth noting that rather small deviations are observed even for large three-cyclic condensed molecules (59,60).…”

Energetic effects of ether and ketone functional groups in 9,10-dihydroanthracene compound

“…The equivalent energies of the calorimeter during the study of anthrone and xanthene were e(calor) = 15551.7 ± 1.2 J Á K À1 (from six experiments) and e(calor) = 15546.3 ± 1.3 J Á K À1 (from eight experi-FIGURE 1. Views of the molecular structures of anthrone (1) and xanthene (2) optimized at the B3LYP/6-31G(d).…”

“…The G3(MP2)//B3LYP approach was used successfully in previous works for the calculation of the standard molar enthalpies of formation of other polycyclic compounds [1][2][3][4][5].…”

“…Recently, some thermochemical data in particular for heteropolycyclic compounds containing oxygen and sulfur have been published [1][2][3][4][5]. Herewith, there is presented an experimental and computational thermochemical study of two tricyclic compounds, namely, anthrone ((10H)-9-anthracenone) and xanthene ((10H)-9-oxaanthracene), whose basic structure is the 9,10-dihydroanthracene moiety.…”

Experimental and computational thermochemical studies of 9-R-xanthene derivatives (ROH, COOH, CONH2)

“…The objectives of this work are the understanding of the energetic effect of three different substituents on position 9 of xanthene (figure 1) and, anchored on data coming from some other studies performed earlier, the quantification of the effects of substituting an oxygen heteroatom by sulfur in heteropolycyclic compounds [7][8][9][10][11][12][13].…”