THERMODYNAMIC AND TOPOLOGICAL INVESTIGATIONS IN BINARY-MIXTURES CONTAINING NITROBENZENE

Molar excess volumes, V-E, and molar excess enthalpies, H-E, for vario us nitrobenzene (i) +aniline, +N-methylaniline and +N,N-dimethylanilin e (j) mixtures have been measured as a function of composition at 308. 15 K. The observed data have been analysed in terms of graph-theoretic al approach and Sanchez and Lacombe's approach. The analysis of V-E da ta by graph-theoretical approach reveals that nitrobenzene, aniline, N -methyl aniline and N,N-dimethyl aniline exist as associated entities and these mixtures are characterised by the interactions between the d elocalised pi-electron cloud over nitrogen and oxygen atoms of the nit ro group of nitrobenzene and hydrogen atoms of aniline and N-methyl an iline. The present (i+j) mixtures contain 1:1 molecular complex. The I R studies lend additional support to the nature and extent of interact ions for proposed structures in the mixtures. The energetics of the mi xtures have also been discussed.