Association Studies Between Intermolecular Interactions And Their Magnetic Coupling Interactions

For many years the strong anti-ferromagnetic interaction and the spin transition property that displayed from adjacent short contact radicals is hotspot in molecule-based magnetic researching field.But the factors that dominate radical intermolecular magnetic coupling strength are not clearly known.Therefore,the studying and understanding the factors is very meaning for theory and application.This dissertation studied the two main factors that dominate magnetic coupling strength between adjacent short contact radicals,in which the two factors are spin density on the short contact atoms and overlap integral between the short contact atomic pair and the two factors obtained by theoretical calculations.The studied radicals include the reported ethyl-substituted spiro-biphenalenyl neutral radical,the reported radical coordinated anion [Ni(mnt)2]?-and the reported neutral radical [1,3,2]-pyrazodithiozol-2-yl(PDTA),and the three radicals display bistable spin transitions due to intermolecular ?-? short contact.And the same times,the studied radicals also include the reported radical complex [H2DABCO][Ni(mnt)2],the reported radical organic salt {[1,2,5]Thiadiazolo[3,4-c]}{[1,2,5]thiadiazolidyl}2,the reported butyl-substituted spiro-biphenalenyl neutral radical and the reported neutral organic radical 2,5,8-tri-tert-butyl-phenalenyl,and the four radicals exhibit strong anti-ferromagnetic coupling strength because of ?-? short contact interaction between adjacent radicals.In addition,the study also include a neutral biradical bis(verdazyl)ferrocene,which displays the strong anti-ferromagnetic coupling due to intramolecular ?-? short contact interaction.The study first reveals and further confirms the following points.1.If the spin density on each atom of ?-? stacking short contact pair is larger than 0.1,the strong anti-ferromagnetic coupling strength may takes place in the ?-? stacking system;whereas it is not possible that if the system is non ?-? stacking short contact.This point is first revealed and no literature has been reported to date.2.The anti-ferromagnetic coupling strength between short contact radicals or between short contact radical anions is relevant with the overlap integral absolute value between short contact atoms,and the larger overlap integral absolute value,the stronger anti-ferromagnetic coupling strength.This point is also first revealed by this dissertation.3.The dissertation further confirms that the anti-ferromagnetic coupling strength is relevant with the spin densities on short contact atoms,the larger spin density,the stronger the anti-ferromagnetic coupling strength.The results of this dissertation will be very important for designing and synthesizing ideal molecule-based electronic devices in theory and experiment.