The doping reaction of truncated boron nitride and carbon nanotubes with aluminium atom wastheoretically investigated. The AM1, PM3, and PM6 semiempirical methods have been used toevaluate the thermochemistry of doping reactions of single walled boron nitride nanotubes andcarbon nanotubes. The enthalpy changes, Gibbs free energy changes, and entropy changes of studieddoping reactions were evaluated at different temperatures. The AM1 and PM6 results showed Aldopingreaction of (8,0)CNT is exothermic and spontaneous . Among the studied armchair and zigzagnanotubes, AM1 and PM6 calculations reveal that (8,0)CNT is the best candidate for Al-dopingreaction. Manuscript profile

The structures and stability of 531 novel boron nitride substituted isomers of 12-crown-4 etherverified theoretically. For a collection of 23 selected BN isomers, structural geometry, vibrationalstability, energy gaps, natural bond population analysis, and nonlinear optical responses investigatedtheoretically. The changes of standard enthalpies for ionization reactions and electron affinityreactions studied as well. The presence of double bonds in BN isomers of 12c4 might develop theirhost-guest chemistry. Moreover, the results of ionization potentials and electron affinities calculatedby single point calculations showed good correlation with those of thermochemistry ones. Theobserved correlations clearly suggest a lower cost of computations for the mentioned physicalproperties. The polarizability and hyperpolarizability results introduced some BN substituted crownethers as efficient candidates for construction of practical devices for optical harmonic generation andsignal processing. Manuscript profile