The crystal structure of N-（1-adamantyl）urea （tricyclo[3,3,1, 1^3.7]decan-1-urea, C11H18N2O） has been determined by X-ray diffraction. The crystal belongs to the monoclinic system, space group P2（1/c） with a = 1...The crystal structure of N-（1-adamantyl）urea （tricyclo[3,3,1, 1^3.7]decan-1-urea, C11H18N2O） has been determined by X-ray diffraction. The crystal belongs to the monoclinic system, space group P2（1/c） with a = 13.070（2）, b = 8.942（1）, c = 9.390（1） A^°, β= 109.819（8）°, V= 1032.5（2） A^°3, Mr= 194.27, Z = 4, Dc = 1.250 g/cm^3,μ = 0.081 mm^-1, F（000） = 424, R= 0.0427 and wR = 0.1076 for 1105 observed reflections with I〉 2σ（I）. The structure of the title compound consists of an adamantly cage which is a stable tricyclo structure with chair conformation and the substituted urea forms the interlayer-type crystal structure via hydrogen bonds between the molecules.展开更多
Six fully optimized geometries of urea nitrate cation and RDX complexes have been obtained with DFT-B3LYP and MP2 methods at the 6-311＋＋G＊＊ level. The intermolecular interaction energies have been calculated with ...Six fully optimized geometries of urea nitrate cation and RDX complexes have been obtained with DFT-B3LYP and MP2 methods at the 6-311＋＋G＊＊ level. The intermolecular interaction energies have been calculated with basis set superposition error （BSSE） and zero point energy （ZPE） correction. The nature of intermolecular interaction has been revealed by the analysis of AIM and NBO. The results indicate that the greatest binding energy of urea nitrate with RDX is –82.47kJ/mol. The O–H…O and N–H…O hydrogen bonds are important intermolecular interactions of urea nitrate cation with RDX, and the origin of hydrogen bonds is the oxygen atom offering its lone-pair electrons to the σ（O-H）＊ or σ（O-H）＊ antibonding orbital. The intermolecular interactions strengthen the N–NO2 bond, leading to the reduced sensitivity of urea nitrate and RDX mixture explosive.展开更多
基金Supported by the National Natural Science Foundation of China (20571012) and Natural Science Foundation of Beijing (2042013)
文摘The crystal structure of N-（1-adamantyl）urea （tricyclo[3,3,1, 1^3.7]decan-1-urea, C11H18N2O） has been determined by X-ray diffraction. The crystal belongs to the monoclinic system, space group P2（1/c） with a = 13.070（2）, b = 8.942（1）, c = 9.390（1） A^°, β= 109.819（8）°, V= 1032.5（2） A^°3, Mr= 194.27, Z = 4, Dc = 1.250 g/cm^3,μ = 0.081 mm^-1, F（000） = 424, R= 0.0427 and wR = 0.1076 for 1105 observed reflections with I〉 2σ（I）. The structure of the title compound consists of an adamantly cage which is a stable tricyclo structure with chair conformation and the substituted urea forms the interlayer-type crystal structure via hydrogen bonds between the molecules.
文摘Six fully optimized geometries of urea nitrate cation and RDX complexes have been obtained with DFT-B3LYP and MP2 methods at the 6-311＋＋G＊＊ level. The intermolecular interaction energies have been calculated with basis set superposition error （BSSE） and zero point energy （ZPE） correction. The nature of intermolecular interaction has been revealed by the analysis of AIM and NBO. The results indicate that the greatest binding energy of urea nitrate with RDX is –82.47kJ/mol. The O–H…O and N–H…O hydrogen bonds are important intermolecular interactions of urea nitrate cation with RDX, and the origin of hydrogen bonds is the oxygen atom offering its lone-pair electrons to the σ（O-H）＊ or σ（O-H）＊ antibonding orbital. The intermolecular interactions strengthen the N–NO2 bond, leading to the reduced sensitivity of urea nitrate and RDX mixture explosive.
