ENTHALPIES OF PHASE TRANSITIONS OF 5-ARYLFURAN-2-CARBALDEHYDES

Анотація

According to differential thermal analysis the thermodynamic parameters of melting and evaporation
process (kJ/mol) of 5-(2-nitrophenyl)-furan-2-carbaldehyde (D vap H 484,6 = 61,29±0,40; D fus H 368,3 = 33,39±0,70),
5-(3-nitrophenyl)-furan-2-carbaldehyde (D vap H 465,1 = 65,3±1,5; D fus H 428,6 = 36,31±0,44), 5-(4-nitrophenyl)-
furan-2-carbaldehyde (D vap H 523,8 = 79,8±2,2; D fus H 479,8 = 39,86±0,69), 5-(2-nitro-4-methylphenyl)-furan-2-
carbaldehyde (D vap H 439,6 = 75,0±2,0; D fus H 379,2 = 28,10±0,10), 5-(4-methoxy-2-nitrophenyl)-furan-2-
carbaldehyde (D vap H 420,1 = 95,6±2,9; D fus H 372,0 = 35,89±0,07), 5-(2-methyl-4-nitrophenyl)-furan-2-
carbaldehyde (D vap H 466,7 = 87,72±0,34; D fus H 440,4 = 34,7±1,1), 5-(2-methoxy-4-nitrophenyl)-furan-2-
carbaldehyde (D vap H 555,6 = 89,3±2,8; D fus H 490,9 = 36,93±0,13) were determined.

The magnitude of changes in specific entropy of 5-arylfuran-2-carbaldehydes established its
relative permanence. The relatively constant specific entropy change for 5-arylfuran-2-carbaldehydes
(Δ fus S = 0,364 ± 0,016 J/g·K) was established and the possibility of using the calculated values for the
approximate determination of the entropy change during melting and enthalpy change during melting
at the melting temperature for compounds containing both benzene and furan fragment in the
molecule was shown.

Key words: phase transitions, temperature, enthalpy and entropy of melting; enthalpy of
vaporization; 5-arylfurfurals.