Positive electrostatic potential over the central area of the molecular surface is one of the main characteristics of high energetic materials (HEM) that determines their sensitivity towards detonation. The influence...

XÀ H/Pt interactions between cisplatin (cis-[Pt(NH 3 ) 2 Cl 2 ]) and transplatin (trans-[Pt(NH 3 ) 2 Cl 2 ]) molecules as hydrogen atom acceptors and CH 4 , NH 3 and H 2 O molecules as hydrogen atom donors were studied by quantum chemical calculations and analysis of crystallographic data from Cambridge Structural Database (CSD). Results of interaction energies calculations showed that almost in all cases cisplatin molecule forms stronger XÀ H/Pt interaction compared to transplatin molecule. The strongest calculated interaction is OÀ H/Pt interaction between cisplatin and a water molecule with the energy ΔE MP2/ aug-cc-PVDZ =-5.97 kcal/mol; calculated energy of the strongest transplatin/water interaction is ΔE MP2/aug-cc-PVDZ =-4.43 kcal/mol. Only in case of CÀ H/Pt interactions translplatin molecule forms slightly stronger interaction compared to cisplatin molecule; the energy of the strongest CÀ H/Pt interaction involving transplatin molecule is ΔE MP2/aug-cc-PVDZ =-1.20 kcal/mol while for cisplatin energy is ΔE MP2/aug-cc-PVDZ =-1.08 kcal/mol. Interaction energies for geometries with the strongest XÀ H/Pt interactions were re-calculated at CCSD(T)/CBS level and these results were in excellent agreement with results obtained at MP2/aug-cc-PVDZ level of theory. Electrostatic potentials were calculated and used to explain results of interaction energies calculations. Analysis of geometrical data revealed that cisplatin and transplatin molecules are involved in XÀ H/Pt contacts in crystal structures.

The existence of areas of strongly positive electrostatic potential in the central regions of the molecular surface of high-energy molecules is a strong indicator that these compounds are very sensitive towards detonation. Development of high-energy compounds with reduced sensitivity towards detonation and high efficiency is hard to achieve since the energetic molecules with high performance are usually very sensitive. Here we used Density Functional Theory (DFT) calculations to study a series of bis(acetylacetonato) and nitro-bis(acetylacetonato) complexes and to elucidate their potential application as energy compounds with moderate sensitivities. We calculated electrostatic potential maps for these molecules and analyzed values of positive potential in the central portions of molecular surfaces in the context of their sensitivity towards detonation. Results of the analysis of the electrostatic potential demonstrated that nitro-bis(acetylacetonato) complexes of Cu and Zn have similar values of electrostatic potential in the central regions (25.25 and 25.06 kcal/mol, respectively) as conventional explosives like TNT (23.76 kcal/mol). Results of analysis of electrostatic potentials and bond dissociation energies for the C-NO2 bond indicate that nitro-bis(acetylacetonato) complexes could be used as potential energetic compounds with satisfactory sensitivity and performance.